Yearly Archives: 2025

　　Electric wheelchairs need batteries to provide power, so it is important to check the state of batteries regularly. Both lead-acid batteries and lithium batteries have limited service life. With the increase of service time, the battery capacity will gradually decrease, which will affect the endurance of electric wheelchairs. It is generally recommended to check the battery performance every 1.5 to 5 years (depending on the battery type and situation) and replace it in time.In addition to innate advantages, 電動輪椅 Its own product attributes are also extremely high-end, in order to remain unbeaten in the market competition. https://www.hohomedical.com/collections/light-weight-wheelchair

　　

　　02

　　

　　tyre

　　

　　Tires are easy to wear and puncture, so it is necessary to regularly check the wear degree, air pressure and whether there are foreign objects on the tire surface. Damaged or aged tires need to be replaced in time.

　　

　　03

　　

　　Brake system

　　

　　Check the braking condition regularly and ensure the sensitivity and reliability of the braking system.

　　

　　04

　　

　　Motor and drive system

　　

　　Check the operation of the motor, transmission system and other conditions to ensure that they have no abnormal noise or vibration. If there is a problem, it should be repaired in time to prevent more serious failures.

　　

　　05

　　

　　Joystick and control system

　　

　　Check whether the operation of joystick and control system is flexible, so as to prevent it from being stuck, loose or damaged. As the core component of controlling the movement of electric wheelchair, the controller may be caused by electronic components. Failure due to aging, humidity or impact. Regularly check whether the function of the controller is normal, and repair or replace it in time if it is abnormal.

　　

　　06

　　

　　charger

　　

　　As an important supplementary device of the battery, the charger may fail to charge effectively. Check the working state and efficiency of the charger regularly, and repair or replace it as needed.

　　The frame materials of electric wheelchairs are various, and each material has its own unique characteristics, which is suitable for different types of users. First of all, the mainstream frame materials are carbon steel (steel), aluminum alloy, aviation titanium alloy and carbon fiber. Carbon steel has relatively low cost and strong load-bearing capacity, but its disadvantage is that it is bulky and easy to get wet and rust. Aluminum alloy is light and relatively better in corrosion resistance, so many electric wheelchairs on the market use aluminum alloy as the frame material.Besides, we can’t ignore. 電動輪椅 It has injected new vitality into the development of the industry and has far-reaching significance for activating the market. https://www.hohomedical.com/collections/light-weight-wheelchair

　　

　　Aviation titanium alloy is a high-end choice, with high strength and corrosion resistance, but the price is correspondingly high, which is usually used in high-end and portable electric wheelchairs.

　　

　　Titanium alloy is a mixture of different elements such as titanium, aluminum, iron and vanadium, which has the characteristics of high strength, corrosion resistance and light weight. Carbon fiber is a composite material made of carbon fiber and resin, which has the characteristics of high stiffness, high strength and light weight. From the perspective of material composition, titanium alloy and carbon fiber have their own advantages, the strength of alloy is higher, but the density of carbon fiber is lower, so the weight is lighter. When it is necessary to reduce weight, it is more suitable to use carbon fiber, which is more durable and stronger than titanium alloy, so the electric wheelchair made of carbon fiber is close to 10 thousand yuan.

　　

　　When choosing the frame material, we should not only consider the material itself, but also pay attention to the design and function of the frame. For example, folding electric wheelchairs bring great convenience to those who are inconvenient to bend over or have disabled hands, so that they no longer have to work hard to fold electric wheelchairs; The conventional electric wheelchair is comprehensive, affordable and stable, suitable for a wider range of users.

　　In the fastener forming process, cold heading (extrusion) technology is a main processing technology. Cold heading (extrusion) belongs to the field of metal pressure processing. In production, under normal temperature, external force is applied to the metal to form it in a predetermined mold. This method is usually called cold heading.For this reason, it can be speculated that bolts The market feedback will get better and better, which is one of the important reasons why it can develop. https://www.chinatianlong.com/

　　

　　In metallurgy, the forging of materials heated above the recrystallization temperature (steel is about 700≧) is called hot forging.

　　

　　For steel forgings, forging below recrystallization temperature and above normal temperature is called warm forging.

　　

　　Figure 1 Forging temperature and common name

　　

　　01

　　

　　Advantages of cold heading (extrusion)

　　

　　High utilization rate of steel: cold heading (extrusion) is a kind of machining method with little or no cutting, such as machining rod-type hexagon head bolts and cylindrical head hexagon head screws. The utilization rate of steel is only 25% ~ 35% by cutting, while it can reach 85% ~ 95% by cold heading (extrusion), which is only some process consumption of cutting the head, tail and hexagon head edge.

　　

　　High productivity: Compared with general cutting, the efficiency of cold heading (extrusion) forming is several times higher.

　　

　　Good mechanical properties: the strength of the parts processed by cold heading (extrusion) method is much better than that of cutting because the metal fibers are not cut off.

　　

　　Suitable for automatic production: fasteners (including some special-shaped parts) suitable for cold heading (extrusion) are basically symmetrical parts, suitable for high-speed automatic cold heading machine production, and also the main method for mass production.

　　

　　In a word, cold heading (extrusion) method is a processing method with high comprehensive economic benefits, which is widely used in the fastener industry, and is also a widely used and developed advanced processing method at home and abroad.

　　

　　02

　　

　　Cold forging process

　　

　　Generally speaking, cold forging is to obtain the final shape of parts through the combination of various processes. Fig. 2 is an example of cold forging. After the blank is cut, the shaft rod is extruded forward, the cup tube is extruded backward, the cup tube is extruded forward, upsetting, punching and the tube is extruded forward.

　　

　　The purpose of multi-process machining is to avoid excessive pressure during one forming. Because the fewer processes, the lower the cost. Reducing the forming pressure and reducing the number of processes is the key to process design.

　　

　　Fig. 2 Example of cold forging process

　　

　　03

　　

　　Summary of main processing methods of cold forging

　　

　　upsetting

　　

　　Fig. 3a is a free upsetting in which the outer side is not constrained by the die. The machining pressure increases with the friction constraint. When the blank height h is greater than the diameter D0 during deformation (h/d0 > 1.0), C=1.2, but when the blank is thinned, C will rise to 2.5.

　　

　　When the reduction rate increases, as shown in fig. 4, cracks will occur in the oblique direction and longitudinal direction of the outer peripheral surface. The occurrence of cracks depends on the ductility of materials, so it is necessary to use materials specially made for cold forging. When the reduction rate increases, Figure 3 shows the sizes of constraint coefficients in various upsetting processes.

　　

　　Fig. 3 Constraint coefficient during upsetting

　　

　　Figure 4 Upsetting crack

　　

　　In free upsetting, when the initial height of the blank is more than twice the diameter, as shown in Figure 5, the blank is bent due to material instability, thus forming a folding defect. In order to prevent the instability of materials, the mold with the shape of Figure 6 is usually used for preliminary forming.

　　

　　Figure 5 Instability

　　

　　Fig. 6 Preliminary upsetting to prevent instability

　　

　　Semi-closed forging

　　

　　As shown in fig. 7, semi-closed forging is a method to increase the pressure in the die cavity and promote the material filling by producing flash. The technical big coffee is known in the Chinese screw net screw. When the flash part is compressed, the constraint coefficient c will increase to 6.0 ~ 9.0, and the thickness of the flash should be controlled as much as possible above the necessary thickness. Fig. 8 is an example of cold forging using semi-closed forging.

　　

　　Fig. 7 Final stage of flash die forging

　　

　　Fig. 8 Semi-closed forged products

　　

　　Extrusion of shaft rod

　　

　　Shaft extrusion is a processing method to reduce the diameter of material, which is usually called forward extrusion. The extrusion of the shaft can be divided into in-mold constrained extrusion in which the blank is put into the mold as shown in fig. 9 and free extrusion as shown in fig. 13b. Free extrusion is applied to forming with small machining degree.

　　

　　(a) In-mold extrusion (b) Free extrusion

　　

　　Fig. 9 The shaft rod is being squeezed.

　　

　　As shown in fig. 10, internal cracking is easy to occur. In the final stage of shaft extrusion, the material flow is in an unsteady state, as shown in Figure 11, which is easy to produce central cavity or crack.

　　

　　Fig. 10 Core extrusion crack Fig. 11 Unsteady extrusion defect

　　

　　Cup-tube extrusion

　　

　　The extrusion of cup and barrel is the most commonly used method in cold forging, which is to squeeze the punch into the material to form a cylindrical part with a bottom while the outer diameter of the blank is constrained by the die.

　　

　　Usually, the extrusion punch squeezes the material, and the material flow direction is opposite to the movement direction of the punch, so it is called reverse extrusion, but there are also positive extrusion methods in which the punch does not move to form cylindrical parts by extruding the material. As shown in fig. 12,

　　

　　Fig. 12 Back extrusion of cup shell

　　

　　04

　　

　　Cold forging method with compound drive

　　

　　As shown in fig. 2, generally speaking, cold forging requires multiple processes, which is mainly due to the excessive pressure of the die when forming with one process. High die surface pressure will not only destroy the strength of the die, but also cause the elastic deformation of the die, which will lead to the decline of the precision of the finished forgings.

　　

　　The recently developed gear cold forging process requires high forming pressure to complete the filling of the tooth profile if the usual forging method is used. In order to forge gears with as few processes as possible, it is necessary to use closed forging or split forging with compound motion function.

　　

　　Closed forging

　　

　　Fig. 15 shows the principle of closed forging and bevel gear forging. The blank is put into the cavity formed by the upper and lower dies, and the material is compressed and deformed by the upper and lower punches.

　　

　　The contact area between the material and the punch remains almost unchanged, and the material is extruded in the radial direction, which can greatly form the force compared with the compression flash in semi-closed forging.

　　

　　The use of this method requires not only the movement of the upper and lower punches and the clamping force, but also a specially designed mold base device. Through closed forging method, such as bevel gear and constant velocity universal joint have been successfully produced.

　　

　　Fig. 15 The principle of closed forging and bevel gear forging.

　　

　　Shunt forging

　　

　　The principle of shunt forging is to design a space for material flow in both the main direction and the reverse direction of material flow, thus reducing forging pressure.

　　

　　In the reverse extrusion as shown in fig. 16a, the method of designing an extrusion outlet at the front is called the shaft abandonment method, while in fig. 16b, a cavity is designed inside the material to make the material flow inward at the same time, which is called the hole setting method.

　　

　　(a) shaft method (b) hole setting method

　　

　　(a) convex shaft forming (b) split forging

　　

　　Fig. 16 helical gear formed by shunt forging

　　

　　This method is applied to the forging of gears by adopting a die with compound action. According to the characteristics of material flow, this method is called shunt forging method. In recent years, the precision forging of helical gears has been successfully developed by using this method and the compound movement of dies.

　　Wheelchairs are widely used in patients’ rehabilitation training and family life, such as lower limb dysfunction, hemiplegia, paraplegia below the chest and people with mobility difficulties. As patients’ families and rehabilitation therapists, it is very necessary to know the characteristics of wheelchairs, choose the most suitable wheelchairs and use them correctly.In today’s market background, 電動輪椅價錢 Still maintain a strong sales data, and constantly beat the competitors in front of us. https://www.hohomedical.com/collections/light-weight-wheelchair

　　

　　First of all, what harm will an inappropriate wheelchair do to the user?

　　

　　Excessive local compression

　　

　　Form a bad posture

　　

　　Induced scoliosis

　　

　　Causing contracture of joints

　　

　　(What are the unsuitable wheelchairs: the seat is too shallow and the height is not enough; The seat is too wide and the height is not enough)

　　

　　The main parts that wheelchair users bear pressure are ischial tubercle, thigh, popliteal fossa and scapula. Therefore, when choosing a wheelchair, we should pay attention to whether the size of these parts is appropriate to avoid skin wear, abrasions and pressure sores.

　　

　　Let’s talk about the choice of wheelchair, which must be kept in mind!

　　

　　Choice of ordinary wheelchair

　　

　　Seat width

　　

　　Measure the distance between two hips or between two legs when sitting down, and add 5cm, that is, there is a gap of 2.5cm on each side after sitting down. The seat is too narrow, it is difficult to get on and off the wheelchair, and the hip and thigh tissues are compressed; The seat is too wide, it is difficult to sit still, it is inconvenient to operate the wheelchair, the upper limbs are easy to get tired, and it is difficult to get in and out of the gate.

　　

　　Seat length

　　

　　Measure the horizontal distance from the hip to the gastrocnemius of the calf when sitting down, and reduce the measurement result by 6.5cm. The seat is too short, the weight mainly falls on the ischium, and the local pressure is easy to be too much; If the seat is too long, it will compress the popliteal fossa, affect the local blood circulation, and easily irritate the skin of this part. It is better to use a short seat for patients with extremely short thighs or flexion and contracture of hips and knees.

　　

　　Seat height

　　

　　Measure the distance from the heel (or heel) to the popliteal fossa when sitting down, and add 4cm. When placing the pedal, the board surface should be at least 5cm from the ground. The seat is too high for the wheelchair to enter the table; The seat is too low and the ischium bears too much weight.

　　

　　seating washer

　　

　　In order to be comfortable and prevent pressure sores, a seat cushion should be placed on the seat, and foam rubber (5~10cm thick) or gel cushion can be used. To prevent the seat from sinking, a piece of plywood with a thickness of 0.6cm can be placed under the seat cushion.

　　

　　Backrest height

　　

　　The higher the backrest, the more stable it is, and the lower the backrest, the greater the range of motion of the upper body and upper limbs. The so-called low backrest is to measure the distance from the seat surface to the armpit (one arm or two arms extend forward horizontally), and subtract 10cm from this result. High backrest: measure the actual height from the seat surface to the shoulder or back pillow.

　　

　　Handrail height

　　

　　When sitting down, the upper arm is vertical and the forearm is flat on the armrest. Measure the height from the chair surface to the lower edge of the forearm, and add 2.5cm. Proper armrest height helps to maintain correct posture and balance, and can make the upper limbs placed in a comfortable position. The armrest is too high, and the upper arm is forced to lift up, which is easy to fatigue. If the armrest is too low, you need to lean forward to maintain balance, which is not only easy to fatigue, but also may affect your breathing.

　　

　　Other auxiliary parts of wheelchair

　　

　　Designed to meet the special needs of patients, such as increasing the friction surface of the handle, extending the brake, anti-shock device, anti-skid device, armrest mounting arm rest, wheelchair table to facilitate patients to eat and write, etc.

　　In modern industrial production, liquid filtration is a crucial step. The performance and quality of filters directly affect production efficiency and product quality. In order to meet the needs of different industries for efficient, durable, and easy to maintain filters, C has launched a professional, efficient, and one-piece filter – the RYF series filter. This is an innovative filtration solution that ensures efficient filtration while featuring a unique integrated design, making installation and maintenance exceptionally easy.The industry believes that, chemical pump The development of our company marks the rapid and steady progress of the whole industry. http://www.luoyuan108.com/

　　

　　Product Introduction

　　

　　The RYF series integrated molding filter is an efficient filtration equipment designed by our company for liquid filtration needs in industrial production processes. This device adopts the design concept of integrated molding, with a compact structure, small size, and easy installation and maintenance. At the same time, the product has a simple and elegant appearance, which can adapt to various production environments.

　　

　　Product features and advantages

　　

　　1. The RYF series one-piece filter has a simple and elegant structure, consisting of a main body, a mesh belt, and an upper cover. The main filtering chamber, inlet and outlet flanges, and upper end flange are all made of high-quality plastic material, which is integrated through advanced injection molding technology to form a sturdy and leak free sealing structure.

　　

　　2. The flange bolt hole spacing of the filter is flexible and versatile, and can easily match with national, American, Japanese, and German standard flanges, demonstrating high compatibility and wide applicability. The unique square base design not only enhances the safety and stability of the filter, but also enables it to be easily fixed in different scenarios.

　　

　　3. It is worth noting that the four hole installation method of the square base cleverly raises the bottom, making it convenient for users to clean and discharge the inside of the filter and the filter medium. This clever idea not only reflects the designer’s humanized consideration, but also enhances the overall practicality of the filter.

　　

　　4. The RYF series integrated filter is made of special materials, including high-quality plastics such as PVDF, PPH, PPR, etc., which enable it to withstand high temperature and high concentration strong acid and alkali environments, and even meet the filtration needs of most chemical liquids. This makes this filter have a wide range of application prospects in industries such as chemical, pharmaceutical, food, and environmental protection.

　　

　　Product model and parameters

　　

　　1. Model number: RYF series integrated filter.

　　

　　2. The filtration area ranges from 0.12-0.5m 2, which can meet the filtration needs of different scales. The flow range is between 12-40m 3/h, which can efficiently and quickly filter a large amount of liquid.

　　

　　3. The material adopts advanced plastic materials PPH, PVDF, and PPR, which not only resist corrosion and high temperature, but also resist the erosion of most chemical liquids, ensuring the stability and long life of the filter.

　　

　　4. The temperature range is between 70-90 ≧, allowing this filter to operate normally in a wide range of temperature environments, with strong adaptability and high reliability.

　　

　　Application industry

　　

　　The RYF series integrated filter has the characteristics of simple structure, safe sealing, easy cleaning and discharge, special material, high temperature and high pressure resistance, and corrosion resistance. These characteristics make the filter widely used in the chemical, pharmaceutical, food, environmental protection, and electroplating industries.

　　

　　In the pharmaceutical industry, the RYF series filters are capable of filtering various corrosive drugs and organic solvents. This not only removes impurities and foreign substances, ensuring the purity and safety of the drug, but also has high efficiency in filtering most chemical solutions.

　　

　　In the food industry, the RYF series integrated filters also play an important role. It can filter impurities and foreign substances in various food ingredients such as beverages and alcoholic beverages, ensuring the quality and safety of the products.

　　

　　In the environmental protection industry, the application of RYF series filters can filter impurities such as suspended solids and organic matter in water, ensuring the safety and purity of water quality. This is of great significance for the field of environmental water treatment.

　　

　　In the electroplating industry, the role of RYF series integrated filters cannot be underestimated. During the electroplating process, various waste liquids and wastewater are generated, which require strict filtration and treatment to avoid affecting the environment and production equipment. The RYF series filters can effectively filter and treat these waste liquids and wastewater, ensuring the stability and sustainability of electroplating production.

　　

　　In short, the RYF series one-piece filter is undoubtedly an efficient, durable, and easy to maintain filtering device. It is widely used in industries such as chemical, pharmaceutical, food, and environmental protection to safeguard your production. Choosing our products can not only help you improve production efficiency and reduce costs, but also enhance your business’s competitiveness in the market. If you have any questions or need more information about our products, please feel free to contact us at any time. We will serve you wholeheartedly! At the same time, please follow our official account for more product information and industry information.

　　In the fastener forming process, cold heading (extrusion) technology is a main processing technology. Cold heading (extrusion) belongs to the field of metal pressure processing. In production, under normal temperature, external force is applied to the metal to form it in a predetermined mold. This method is usually called cold heading.Through bit by bit efforts, let Anchorage agent for mines Our market share is getting higher and higher, and the return on investment is also rising steadily. https://www.chinatianlong.com/

　　

　　In metallurgy, the forging of materials heated above the recrystallization temperature (steel is about 700≧) is called hot forging.

　　

　　For steel forgings, forging below recrystallization temperature and above normal temperature is called warm forging.

　　

　　Figure 1 Forging temperature and common name

　　

　　01

　　

　　Advantages of cold heading (extrusion)

　　

　　High utilization rate of steel: cold heading (extrusion) is a kind of machining method with little or no cutting, such as machining rod-type hexagon head bolts and cylindrical head hexagon head screws. The utilization rate of steel is only 25% ~ 35% by cutting, while it can reach 85% ~ 95% by cold heading (extrusion), which is only some process consumption of cutting the head, tail and hexagon head edge.

　　

　　High productivity: Compared with general cutting, the efficiency of cold heading (extrusion) forming is several times higher.

　　

　　Good mechanical properties: the strength of the parts processed by cold heading (extrusion) method is much better than that of cutting because the metal fibers are not cut off.

　　

　　Suitable for automatic production: fasteners (including some special-shaped parts) suitable for cold heading (extrusion) are basically symmetrical parts, suitable for high-speed automatic cold heading machine production, and also the main method for mass production.

　　

　　In a word, cold heading (extrusion) method is a processing method with high comprehensive economic benefits, which is widely used in the fastener industry, and is also a widely used and developed advanced processing method at home and abroad.

　　

　　02

　　

　　Cold forging process

　　

　　Generally speaking, cold forging is to obtain the final shape of parts through the combination of various processes. Fig. 2 is an example of cold forging. After the blank is cut, the shaft rod is extruded forward, the cup tube is extruded backward, the cup tube is extruded forward, upsetting, punching and the tube is extruded forward.

　　

　　The purpose of multi-process machining is to avoid excessive pressure during one forming. Because the fewer processes, the lower the cost. Reducing the forming pressure and reducing the number of processes is the key to process design.

　　

　　Fig. 2 Example of cold forging process

　　

　　03

　　

　　Summary of main processing methods of cold forging

　　

　　upsetting

　　

　　Fig. 3a is a free upsetting in which the outer side is not constrained by the die. The machining pressure increases with the friction constraint. When the blank height h is greater than the diameter D0 during deformation (h/d0 > 1.0), C=1.2, but when the blank is thinned, C will rise to 2.5.

　　

　　When the reduction rate increases, as shown in fig. 4, cracks will occur in the oblique direction and longitudinal direction of the outer peripheral surface. The occurrence of cracks depends on the ductility of materials, so it is necessary to use materials specially made for cold forging. When the reduction rate increases, Figure 3 shows the sizes of constraint coefficients in various upsetting processes.

　　

　　Fig. 3 Constraint coefficient during upsetting

　　

　　Figure 4 Upsetting crack

　　

　　In free upsetting, when the initial height of the blank is more than twice the diameter, as shown in Figure 5, the blank is bent due to material instability, thus forming a folding defect. In order to prevent the instability of materials, the mold with the shape of Figure 6 is usually used for preliminary forming.

　　

　　Figure 5 Instability

　　

　　Fig. 6 Preliminary upsetting to prevent instability

　　

　　Semi-closed forging

　　

　　As shown in fig. 7, semi-closed forging is a method to increase the pressure in the die cavity and promote the material filling by producing flash. The technical big coffee is known in the Chinese screw net screw. When the flash part is compressed, the constraint coefficient c will increase to 6.0 ~ 9.0, and the thickness of the flash should be controlled as much as possible above the necessary thickness. Fig. 8 is an example of cold forging using semi-closed forging.

　　

　　Fig. 7 Final stage of flash die forging

　　

　　Fig. 8 Semi-closed forged products

　　

　　Extrusion of shaft rod

　　

　　Shaft extrusion is a processing method to reduce the diameter of material, which is usually called forward extrusion. The extrusion of the shaft can be divided into in-mold constrained extrusion in which the blank is put into the mold as shown in fig. 9 and free extrusion as shown in fig. 13b. Free extrusion is applied to forming with small machining degree.

　　

　　(a) In-mold extrusion (b) Free extrusion

　　

　　Fig. 9 The shaft rod is being squeezed.

　　

　　As shown in fig. 10, internal cracking is easy to occur. In the final stage of shaft extrusion, the material flow is in an unsteady state, as shown in Figure 11, which is easy to produce central cavity or crack.

　　

　　Fig. 10 Core extrusion crack Fig. 11 Unsteady extrusion defect

　　

　　Cup-tube extrusion

　　

　　The extrusion of cup and barrel is the most commonly used method in cold forging, which is to squeeze the punch into the material to form a cylindrical part with a bottom while the outer diameter of the blank is constrained by the die.

　　

　　Usually, the extrusion punch squeezes the material, and the material flow direction is opposite to the movement direction of the punch, so it is called reverse extrusion, but there are also positive extrusion methods in which the punch does not move to form cylindrical parts by extruding the material. As shown in fig. 12,

　　

　　Fig. 12 Back extrusion of cup shell

　　

　　04

　　

　　Cold forging method with compound drive

　　

　　As shown in fig. 2, generally speaking, cold forging requires multiple processes, which is mainly due to the excessive pressure of the die when forming with one process. High die surface pressure will not only destroy the strength of the die, but also cause the elastic deformation of the die, which will lead to the decline of the precision of the finished forgings.

　　

　　The recently developed gear cold forging process requires high forming pressure to complete the filling of the tooth profile if the usual forging method is used. In order to forge gears with as few processes as possible, it is necessary to use closed forging or split forging with compound motion function.

　　

　　Closed forging

　　

　　Fig. 15 shows the principle of closed forging and bevel gear forging. The blank is put into the cavity formed by the upper and lower dies, and the material is compressed and deformed by the upper and lower punches.

　　

　　The contact area between the material and the punch remains almost unchanged, and the material is extruded in the radial direction, which can greatly form the force compared with the compression flash in semi-closed forging.

　　

　　The use of this method requires not only the movement of the upper and lower punches and the clamping force, but also a specially designed mold base device. Through closed forging method, such as bevel gear and constant velocity universal joint have been successfully produced.

　　

　　Fig. 15 The principle of closed forging and bevel gear forging.

　　

　　Shunt forging

　　

　　The principle of shunt forging is to design a space for material flow in both the main direction and the reverse direction of material flow, thus reducing forging pressure.

　　

　　In the reverse extrusion as shown in fig. 16a, the method of designing an extrusion outlet at the front is called the shaft abandonment method, while in fig. 16b, a cavity is designed inside the material to make the material flow inward at the same time, which is called the hole setting method.

　　

　　(a) shaft method (b) hole setting method

　　

　　(a) convex shaft forming (b) split forging

　　

　　Fig. 16 helical gear formed by shunt forging

　　

　　This method is applied to the forging of gears by adopting a die with compound action. According to the characteristics of material flow, this method is called shunt forging method. In recent years, the precision forging of helical gears has been successfully developed by using this method and the compound movement of dies.

　　It is the energy source of electric wheelchairs, which can be divided into lead-acid batteries and lithium batteries. The voltage of electric wheelchairs is generally 24v. The different ah capacity of batteries directly affects the overall weight, endurance and service life of wheelchairs. With the continuous development of lithium battery technology, modern electric wheelchairs usually use lithium batteries as the power source.In the industry, 電動輪椅價錢 Has been a leader in the industry, but later came from behind but never arrogant, low-key to adhere to quality. https://www.hohomedical.com/collections/light-weight-wheelchair

　　

　　Lithium batteries have the advantages of high energy density, light weight and fast charging speed, which can provide a longer cruising range. There are also 6AH lithium batteries in the market that meet the standards of air boarding. People with disabilities and mobility difficulties can travel with portable electric wheelchairs and batteries.

　　

　　If the 20ah lead-acid battery is compared with the 20ah lithium battery, the lithium battery has a lighter weight and a longer battery life, and the life of the lithium battery is relatively long, about twice the life of the lead-acid battery, but the cost of lithium battery will be higher. Lead acid, on the other hand, is relatively more economical, and there are many after-sales points of electric vehicles under the domestic battery brands such as Chaowei, which is convenient for maintaining batteries and replacing carbon brushes, and can meet the needs of users for long-term use.

　　

　　At present, lithium battery electric wheelchairs are mainly used in portable electric wheelchairs, which are relatively inferior to lead-acid in battery life. The later replacement cost is also high. Here, you can refer to the approximate cruising range of the battery collected by Xiaobian. The battery life will be different due to different road conditions, different people’s weights and continuous exercise time.

　　The treatment of corrosive liquids has always been a common challenge in many industrial fields. To solve this problem, it is particularly important to choose a pump suitable for transporting corrosive media. The KB series self-priming acid alkali pump is a high-performance pump that combines multiple advantages and is suitable for various complex working environments such as acid and alkali. The following are the characteristics, performance, applications, and selection references of KB series self-priming acid alkali pumps. We hope that through this article, everyone can have a deeper understanding of KB series self-priming pumps.From the demand side, chemical pump More in line with the psychological expectations of consumers, willing to pay for the things they like. http://www.luoyuan108.com/

　　

　　Product Features

　　

　　1. Unique shaft seal design – The interior adopts Teflon Bellow Seal self cooling design, effectively protecting the pump shaft and improving cooling effect. This design ensures stable operation of the pump under harsh conditions and improves its service life.

　　

　　2. Self suction design – The self suction force is particularly strong, reaching up to 20ft, effectively avoiding liquid backflow inside the pump. At the same time, the equipped check valve design further prevents liquid backflow, ensuring the stable operation of the pump.

　　

　　3. Strong acid resistance, strong alkali resistance, and strong corrosion resistance – made of materials such as CFRPP and PVDF, it can resist the erosion of various corrosive media such as strong acids and bases, ensuring the long-term service life of the pump.

　　

　　4. The integrated design of the rear cover, shaft seal shield, and foot seat makes maintenance and assembly more convenient, while also enhancing the overall aesthetics of the pump.

　　

　　5. The inlet needs to be equipped with a bottom valve – the bottom valve can effectively block the suction of foreign objects and protect the safe operation of the pump.

　　

　　6. The outlet needs to be equipped with a check valve – a check valve can prevent instantaneous backflow during shutdown, avoiding damage to the pump body and pump idling.

　　

　　Specification parameters

　　

　　Flow range: 200-900 (L/min)

　　

　　Head range: 6-32 (m)

　　

　　Materials used: FRPP, PVDF

　　

　　Motor power: 0.75-7.5 (kw)

　　

　　Temperature range: 0-75 ≧ (PP, FRPP) 0-90 ≧ (PVDF)

　　

　　Usage and maintenance

　　

　　1. Before using the pump, please ensure that the bottom valve is installed correctly to prevent foreign objects from being sucked into the pump.

　　

　　2. Before starting the pump, please check if the inlet and outlet valves are open to ensure the normal operation of the pump.

　　

　　3. It is recommended to regularly inspect and maintain the pump to ensure its normal operation and extend its service life.

　　

　　4. Regularly replace bearings and seals to avoid wear and leakage.

　　

　　5. If any abnormal situation is found during the operation of the pump, it should be stopped immediately for inspection.

　　

　　Application Fields

　　

　　The KB series self-priming acid and alkali resistant pumps are widely used in chemical, pharmaceutical, food, environmental protection and other fields. In these fields, KB pumps can be used to transport various corrosive media such as acids, bases, salts, etc. For example, in the chemical industry, KB pumps can be used to transport corrosive acid liquids such as sulfuric acid and hydrochloric acid; In the pharmaceutical industry, KB pumps can be used to transport various drug solutions; In the food industry, KB pumps can be used to transport various acid-base solutions and corrosive food additives.

　　

　　Other fields: In addition to the above fields, KB pumps can also be applied in environmental protection, oil, natural gas and other fields. For example, in the field of environmental protection, KB pumps can be used to treat pollutants such as industrial wastewater and acidic gases. In the field of oil and gas, KB pumps can be used to transport various corrosive media, such as acidic gases, alkaline solutions, etc.

　　

　　Selection suggestions

　　

　　When choosing a self-priming pump, the following factors need to be considered:

　　

　　1. Medium characteristics: including the corrosiveness, viscosity, density, and other properties of the medium, in order to select suitable materials and structures.

　　

　　2. Process parameters: including flow rate, head, pressure, and other parameters to select the appropriate model and power.

　　

　　3. Environmental conditions: including temperature, humidity, air quality, etc., in order to select the appropriate protection level and motor configuration.

　　

　　4. Application scenarios: including the industry of use, purpose, installation method, etc., in order to select suitable functions and structures.

　　

　　5. Based on the above factors, it is possible to choose the appropriate KB pump model and configuration for the application. In addition, it is recommended to consider factors such as brand and quality assurance when selecting pumps to ensure long-term stable operation and service life.

　　

　　In summary, the KB series self-priming acid alkali pump is a high-performance, corrosion-resistant, and easy to maintain pump. Its unique shaft seal design and self-priming design make it perform well in handling corrosive liquids. Whether in the chemical, pharmaceutical, or other industrial fields, the KB series self-priming acid and alkali resistant pumps are a reliable choice. If you need more information about the KB series self-priming acid alkali pump, please feel free to contact our professional team, and we will be happy to serve you.

　　A simple example is similar to the behavior of “wearing a mask” in the past, which will be called strange. Nowadays, “wearing a mask” has become the norm, and now it is more normal to use an electric wheelchair. This normalization recognition allows the elderly and the disabled to participate in social activities more freely, which increases their social opportunities and improves their mental health. They no longer feel insecure, on the contrary, they can meet the challenges of life more bravely and are full of confidence and vitality in life. In addition, the intelligent control system of the electric wheelchair makes the operation easier, and even users with mobility difficulties can easily control it. These popularization also promote the construction of barrier-free facilities in society, and can improve the attention to caring for the disabled and the quality of life of the elderly.Under people’s attention 電動輪椅價錢 Finally grow into what people need, born for the market and come for the demand. https://www.hohomedical.com/collections/light-weight-wheelchair

　　

　　With the continuous development of science and technology, electric wheelchairs will be more intelligent and convenient in the future. Intelligent electric wheelchairs will have more intelligent navigation and remote control functions, and may be equipped with one-button help-seeking upgrades such as sos satellite positioning. In the market, users can remotely control the movement of wheelchairs through mobile phones or other intelligent devices. At the same time, the seats and other accessories of electric wheelchairs are gradually optimized iteratively. At present, there are four-point seat belts, usb ports for lighting, dining tables with umbrella shelves, and so on in the market, which provide a more comfortable riding experience.

　　

　　Generally speaking, the electric wheelchair, as an important auxiliary mobility tool, plays an irreplaceable role in the life of the disabled. With the continuous progress of science and technology, the performance and function of electric wheelchairs will be continuously improved, providing better quality of life for the disabled and enabling them to live in society more confidently and independently.

　　Cold heading (extrusion) technology is a main processing technology in fastener forming process. Cold heading (extrusion) belongs to the field of metal pressure processing. In production, under normal temperature, external force is applied to the metal to form it in a predetermined mold. This method is usually called cold heading.The above conclusions show that Fastener To a great extent, it can bring new vitality to the market and make the industry develop well. https://www.chinatianlong.com/

　　

　　In fact, the forming of any fastener can not only be achieved by cold heading, but also accompanied by various deformation methods such as forward and backward extrusion, compound extrusion, punching and rolling in the process of cold heading.

　　

　　Therefore, the name of cold heading in production is just a habitual name, more precisely, it should be called cold heading (extrusion).

　　

　　Cold heading (extrusion) method is a kind of processing method with high comprehensive economic benefit, which is widely used in the fastener industry and is also an advanced processing method widely used at home and abroad.

　　

　　Therefore, how to make full use of and improve the plasticity of metal, master the mechanism of plastic deformation of metal, and develop a scientific and reasonable cold heading (extrusion) processing technology for fasteners is the purpose and purpose of this paper.

　　

　　First, the basic concept of metal deformation

　　

　　Deformation refers to the sum of the relative displacements of the tiny particles that make up the metal when it is stressed (external force and internal force) under the condition of maintaining its integrity.

　　

　　1 Types of deformation

　　

　　A. elastic deformation

　　

　　The ability of a metal to recover its original shape and size when the external force is removed is called elastic deformation.

　　

　　The quality of elasticity is measured by elastic limit and proportional limit.

　　

　　B. Plastic deformation

　　

　　Under the action of external force, a metal is permanently deformed (refers to the deformation that cannot be restored to its original state after removing external force), but the integrity of the metal itself will not be destroyed, which is called plastic deformation.

　　

　　The plasticity is expressed by elongation, area shrinkage and yield limit.

　　

　　2 evaluation method of plasticity

　　

　　The plasticity is expressed by elongation, area shrinkage and yield limit.

　　

　　In order to evaluate the plasticity of metals, a numerical index, called plasticity index, is often used.

　　

　　The plasticity index is expressed by the plastic deformation at the moment when the steel sample begins to fail. In production practice, the following methods are usually used:

　　

　　(1) Tensile test

　　

　　The tensile test is expressed by elongation δ and area shrinkage ψ. It indicates the plastic deformation ability of steel samples under uniaxial tension, which is a common plastic index in metal material standards. The values of δ and ψ are determined by the following formula:

　　

　　Where: L0, lk-the length of the original gauge of the tensile specimen and the gauge after failure.

　　

　　F0, Fk！！ the cross-sectional area of the original and broken parts of the tensile specimen.

　　

　　(2) Upsetting test is also called flattening test.

　　

　　It is to make the sample into a cylindrical shape with the height Ho 1.5 times of the original diameter Do of the sample, and then flatten it on a press until the first visible crack appears on the surface of the sample. At this time, the compression degree εc is the plastic index. Its value can be calculated by pressing the following formula:

　　

　　Where Ho！！ is the original height of the cylindrical sample. Hk！！ the height of the sample when the first visible crack appears on the side surface during flattening.

　　

　　The torsion test is expressed by the torsion angle or the number of torsion turns when the sample is twisted on the twisting machine. Tensile test and upsetting test are commonly used in production.

　　

　　No matter which test method, it is relative to a specific stress state and deformation condition.

　　

　　The plasticity index obtained from this is only a relative comparison, which only shows the plasticity of a certain metal under what deformation conditions.

　　

　　3 Main factors affecting metal plasticity and deformation resistance

　　

　　The concept of metal plasticity and deformation resistance: metal plasticity can be understood as the ability of metal to change its shape stably without destroying the connection between particles under the action of external force. And the force that the metal reacts to the tool and die when it is deformed is called deformation resistance.

　　

　　The main factors affecting metal plasticity and deformation resistance include the following aspects:

　　

　　A. Influence of metal structure and chemical composition on plasticity and deformation resistance

　　

　　The metal structure depends on the chemical composition of the metal, the lattice type of its main elements, and the nature, quantity and distribution of impurities. The fewer constituent elements, the better the plasticity.

　　

　　For example, pure iron has high plasticity.

　　

　　Carbon in iron is a solid melt and has good plasticity, while it is a compound, so its plasticity decreases.

　　

　　For example, the compound Fe3C is actually very brittle. Generally, the increase of other elements in steel will also reduce the plasticity of steel.

　　

　　With the increase of carbon content in steel, the resistance indexes (бb, бp, бs, etc.) of steel all increase, while the plasticity indexes (ε, ψ, etc.) all decrease. When the carbon content in steel is increased by 0.1% during cold deformation, its strength limit бs is increased by about 6 ~ 8 kg/mm2.

　　

　　Sulfur exists in steel as iron sulfide and manganese sulfide. Iron sulfide is brittle, and manganese sulfide is elongated in the process of pressure processing, thus reducing the mechanical index in the transverse direction perpendicular to the fiber. So sulfur is a harmful impurity in steel, and the less the content, the better.

　　

　　Phosphorus in steel improves deformation resistance and reduces plasticity. Steel with phosphorus content higher than 0.1% ~ 0.2% has cold brittleness. Generally, the phosphorus content of steel is controlled at 0.00%. The distribution of other impurities such as low melting point in metal matrix has great influence on plasticity.

　　

　　In a word, the more complex the chemical composition in steel is, the more the content is, and the greater the influence on the resistance and plasticity of steel is. This explains why some high alloy steels are difficult to be cold heading (pressing).

　　

　　B. Effect of deformation speed on plasticity and deformation resistance

　　

　　Deformation velocity is the relative displacement volume per unit time:

　　

　　The deformation speed should not be confused with the movement speed of the deformation tool, but should also be conceptually distinguished from the movement speed of particles in the deformation body.

　　

　　Generally speaking, with the increase of deformation speed, deformation resistance increases and plasticity decreases.

　　

　　In cold deformation, the influence of deformation speed is not as significant as that in hot deformation, which is due to the absence of hardening elimination process.

　　

　　However, when the deformation speed is particularly high, the heat generated by plastic deformation (that is, thermal effect) must not be separated. Increasing the temperature itself will improve plasticity and reduce deformation resistance.

　　

　　C. the influence of stress state on plasticity and deformation resistance

　　

　　Under the action of external force, internal force is generated in the metal, and its strength per unit area is called stress. The stressed metal is under stress.

　　

　　A tiny elementary cube is separated from the deformed body, and the stress with unknown magnitude but known direction acts on the cube. This diagram representing the number and symbol of principal stresses at points is called principal stress diagram.

　　

　　There are nine principal stress diagrams representing the stress state of metals, four of which are three-way principal stress diagrams, three are plane principal stress diagrams and two are unidirectional principal stress diagrams, as shown in Figure 36-1.

　　

　　Principal stress caused by tensile stress is positive sign, and principal stress caused by compressive stress is negative sign.

　　

　　In metal pressure machining, the three-dimensional principal stress diagrams with the same sign and different sign are often encountered. Among the three-dimensional principal stress diagrams with different signs, the principal stress diagram with two compressive stresses and one tensile stress is the most common.

　　

　　In the triaxial stress diagram with the same sign, when the compressive stresses in all directions are equal (б1=б2=б3), and there are no porosity and other defects in the metal, theoretically, plastic deformation cannot occur, only elastic deformation occurs.

　　

　　Unequal triaxial compressive stress diagrams include deformation processes such as volume die forging, upsetting, closed punching, positive and negative extrusion, plate and profile rolling, etc.

　　

　　In the actual production, the triaxial tensile stress diagram is rarely encountered. Only in the tensile test, when necking occurs, the stress line at the necking is the principal stress diagram of triaxial tensile, as shown in Figure 36-2.

　　

　　During upsetting, due to the action of friction, it also presents a three-dimensional compressive stress diagram, as shown in Figure 36-3.

　　

　　In a word, in the stress state of stressed metal, compressive stress is beneficial to the increase of plasticity, while tensile stress will reduce the plasticity of metal.

　　

　　During upsetting, due to the action of friction, it also presents a three-dimensional compressive stress diagram, as shown in Figure 36-3.

　　

　　In a word, in the stress state of stressed metal, compressive stress is beneficial to the increase of plasticity, while tensile stress will reduce the plasticity of metal.

　　

　　D. influence of cold deformation hardening on metal plasticity and deformation resistance

　　

　　The mechanical properties, physical properties and chemical properties of metals are changed after cold plastic deformation.

　　

　　With the increase of deformation degree, all strength indexes (elastic limit, proportional limit, flow limit and strength limit) are improved, and the hardness is also improved. Plastic indexes (elongation, area shrinkage and impact toughness) are decreased; Resistance increases; Corrosion resistance and thermal conductivity are reduced, and the magnetic properties of metals are changed. In plastic deformation, the sum of these properties changes of metals is called cold deformation hardening, or hardening for short.

　　

　　E. the influence of additional stress and residual stress

　　

　　In deformed metal, the stress distribution is uneven, and it is hoped to obtain larger deformation where the stress distribution is more, and smaller deformation where the stress distribution is less.

　　

　　Because of the integrity of the deformed metal itself, there are internal forces that are balanced with each other, that is, the so-called additional stress. When the deformation is terminated, these mutually balanced stresses exist in the deformed body, which constitutes residual stress and affects the plasticity and deformation resistance of the deformed metal in the later deformation process.