A valve body machining process for a piston assembly and apparatus used thereby

Abstract

The application provides a valve body machining process of a piston assembly and an equipment used by the valve body machining process, and belongs to the technical field of shock absorbers. The valve body is manufactured by adopting a powder metallurgy process. After blank powder is pressed and sintered, a primary valve body is formed. After surface treatment is performed on the primary valve body, a valve body finished product is obtained. The consistency of the processed valve body is ensured. The problems of pores, flow lines and excessive impurities mixed are eliminated. The microstructure of the valve body is more fine and the quality is higher. Meanwhile, the product forming size can be more accurate, the machining amount can be reduced or eliminated, the material is more saved, the impact resistance is better, the service life is longer, and the use performance of the shock absorber is improved. In addition, a structure with a pressurizing equipment, a top die and a bottom die is arranged. The lifting of the bottom plate in the bottom die is realized by cooperating with a jacking wheel. The automatic ejection of the valve body mold from the blanking requirement is realized under the requirement of the mold of the valve body. The processing efficiency is higher, and the large-scale production and manufacturing requirement of the valve body is met.

Description

Technical Field

[0001] This invention relates to the technical field of shock absorbers, specifically to a valve body processing technology for a piston assembly and the equipment used therein. Background Technology

[0002] Shock absorbers suppress the oscillations caused by the rebound of the spring after absorbing shock and the direct impact from the outside through the movement of the piston assembly in the cylinder. They are widely used in the automotive industry.

[0003] The piston assembly, as the core structure of the shock absorber, includes a piston, a valve body, and valve plates. The piston has several through holes, divided into two groups. Valve plates are located on both sides of the piston; one end of one group of through holes is covered by a valve plate, and the other end of the other group of through holes is covered by another valve plate. Each valve plate has a valve body on the side facing away from the piston. The valve body is a cylindrical structure with a central hole for mounting the piston rod. A ring-shaped protrusion on one end of the valve body provides directional positioning. By pressing the valve plates with the valve body and providing space for deformation, each group of through holes forms a unidirectional flow structure. When the piston assembly moves within the cylinder, the damping medium inside the cylinder impacts the valve plates through the corresponding through holes, causing deformation and achieving a damping effect. Therefore, ensuring the quality of the valve body directly affects the performance of the piston assembly.

[0004] Currently, most valve bodies on the market are cast iron structures, meaning they are formed by casting and then machined. While the process is simple, air can easily get trapped in the mold during casting, leading to defects such as bubbles, incomplete material filling, oxide scale, and other impurities that can easily mix into the fluid. Defects like flow lines and pores are also common, resulting in poor quality. Furthermore, the machining process is extensive, leading to significant material waste. Additionally, because the piston assembly needs to move frequently within the cylinder, the valve body is constantly subjected to the impact of the damping medium, making it highly susceptible to damage, resulting in a shorter service life and affecting the performance of the shock absorber. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention aims to provide a valve body processing technology for piston assemblies and the equipment used therein. The technology employs powder metallurgy, where powder is loaded into a mold, compacted, and then sintered and surface-treated to complete the valve body fabrication. This effectively ensures product consistency, eliminates issues such as porosity, flow lines, and impurities, resulting in a finer microstructure and higher product quality. Furthermore, the molding dimensions are more precise, requiring little or no machining, saving materials, and offering better impact resistance and a longer service life, thus ensuring the performance of the shock absorber. Additionally, the structure incorporates multiple bottom molds and lifting rollers, enabling the sequential pressing and molding of multiple valve body molds. The pressed valve body molds are then ejected from the bottom mold cavities by the lifting rollers and transferred to the subsequent sintering mold via a conveyor belt, improving processing efficiency and adapting to the needs of large-scale production.

[0006] The specific technical solution is as follows:

[0007] A valve body machining process for a piston assembly includes the following steps:

[0008] Step S1: Prepare raw material powder;

[0009] The metal raw materials are crushed and made into metal powder;

[0010] Step S2, preparation of raw powder;

[0011] Different metal powders are mixed evenly in a predetermined ratio to form a blank powder;

[0012] Step S3, mold forming;

[0013] The raw powder is loaded into the molding die, and the pressurizing equipment is started to press the raw powder in the molding die into the mold body of the valve body;

[0014] Step S4, sintering;

[0015] The mold is placed in a graphite boat and transferred to a vacuum furnace for sintering to form a primary valve body;

[0016] Step S5, surface treatment;

[0017] The primary valve body is placed in a steam environment for steam treatment, and an oxide film is formed on the surface of the primary valve body to obtain the finished valve body.

[0018] In the valve body processing technology of the piston assembly described above, after step S4 and before step S5, a gauge is used to inspect the shape, size and flatness of the primary valve body.

[0019] In the valve body processing technology of the aforementioned piston assembly, a temperature measuring hole penetrating the wall is opened on the outer wall of the graphite boat, the temperature measuring hole is provided with a metal sleeve, and a metal plug is provided in the metal sleeve.

[0020] A valve body processing apparatus for a piston assembly, used in step S3 of the aforementioned valve body processing technology for the piston assembly, has the following technical features, including:

[0021] The frame is equipped with an upper platform and an intermediate platform arranged parallel to each other and spaced apart, with the upper platform located above the intermediate platform.

[0022] Several bottom molds are evenly and spaced on an intermediate platform. Several bottom molds are arranged along a straight line on the intermediate platform. Each bottom mold includes an outer mold and a bottom plate. The bottom of the outer mold is fixed to the intermediate platform and has a cavity with an upper opening. An expansion hole is opened on the outer mold and at the center of the bottom wall of the cavity. The bottom plate is set in the cavity, and an expansion rod is set at the bottom of the bottom plate and extends through the expansion hole to the bottom of the outer mold and the intermediate platform.

[0023] A top mold selectively engages with a bottom mold. The top mold selectively extends into the cavity and slides within the cavity. Simultaneously, the bottom of the top mold is provided with a concave cavity and a protruding post. Furthermore, the bottom plate is provided with a concave hole corresponding to the protruding post. When the top mold is pressed into the cavity, the lower end of the protruding post is inserted into the concave hole.

[0024] The pressurizing device is slidably installed on the upper platform along the arrangement direction of several bottom molds. The pressurizing device has a vertically downward pressing rod, and the top mold is fixedly installed on the pressing rod on the side away from the bottom mold.

[0025] A conveyor belt is set on the middle platform and is positioned on the side of the bottom mold along the arrangement direction of several bottom molds;

[0026] Several lifting wheels are rotatably installed below the intermediate platform. Each lifting wheel is a cam, and each lifting wheel corresponds to a bottom mold. The wheel surface of the lifting wheel is in contact with the lower end of the telescopic rod.

[0027] The valve body processing equipment for the piston assembly described above includes an electromagnet embedded in the top mold, a protrusion made of magnetically attractive metal or a permanent magnet embedded at the upper end of the protrusion, and a positioning hole with an flared arrangement at the bottom of the top mold, with the positioning hole located at the center of the electromagnet.

[0028] The valve body processing equipment for the piston assembly described above further includes a sliding drive assembly. The sliding drive assembly is disposed between the upper platform and the pressurizing device. The sliding drive assembly includes a drive screw, a nut, a sliding actuator, and a first reducer. Both ends of the drive screw are rotatably mounted on the upper platform and arranged along the sliding direction with the pressurizing device. The nut is threaded onto the drive screw and fixedly connected to the pressurizing device. Furthermore, the drive screw is poweredly connected to the first reducer, and the first reducer is poweredly connected to the sliding actuator.

[0029] The valve body processing equipment for the piston assembly described above further includes a transmission assembly. The transmission assembly includes a transmission shaft, a drive shaft, a second reducer, and several sets of bevel gear transmission groups. The drive shaft is rotatably mounted below the intermediate platform in a direction parallel to the drive screw, and each lifting wheel is fixedly sleeved on the drive shaft. The transmission shaft is located between the drive screw and the drive shaft, and a set of bevel gear transmission groups is respectively provided at both ends of the transmission shaft and between the drive screw and the drive shaft. At the same time, the second reducer is connected to the drive shaft before connecting to the corresponding bevel gear transmission group.

[0030] In the valve body processing equipment for the piston assembly described above, the protrusions of two adjacent lifting wheels are offset from each other in the rotation plane of the lifting wheels, and the offset angle is 180°.

[0031] The valve body processing equipment for the piston assembly described above includes a stepped hole for the telescopic hole, a guide hole for the larger diameter section of the telescopic hole and a swing hole for the smaller diameter section. The guide hole is located on the side near the base plate, and its depth is greater than the thickness of the valve body mold. The swing hole has a diameter greater than the diameter of the telescopic rod. Two symmetrically arranged guide grooves are provided on the wall of the swing hole along its axial direction. A guide sleeve is provided on the bottom of the base plate and on the outer sleeve of the telescopic rod. The guide sleeve slides in the guide hole. A deflection shaft is provided on the outer wall of the end of the telescopic rod away from the base plate, and both ends of the deflection shaft extend into the two guide grooves respectively.

[0032] In the valve body processing equipment of the piston assembly described above, the orifice of the guide hole at the end opposite to the deflection hole is arranged in a trumpet-shaped flared shape.

[0033] The valve body processing equipment for the piston assembly described above further includes a reset assembly. The reset assembly includes a tension spring and a limiting block. The two ends of the tension spring are respectively fixedly connected to the outer wall of the telescopic rod and the hole wall of the swing hole. The tension spring is arranged radially along the telescopic rod and perpendicular to the deflection axis. At the same time, the tension spring is located in the opposite direction of the rotation direction of the telescopic rod relative to the lifting wheel. Furthermore, a limiting block is provided on the hole wall of the swing hole on the side of the telescopic rod where the tension spring is located. The limiting block contacts the outer wall of the telescopic rod when the telescopic rod is arranged vertically.

[0034] In the valve body processing equipment for the piston assembly described above, ball bearings are provided on the end of the telescopic rod that contacts the wheel surface of the lifting wheel and on the end of the limiting block that contacts the outer wall of the telescopic rod.

[0035] The positive effects of the above technical solution are:

[0036] The aforementioned piston assembly valve body processing technology and equipment utilize powder metallurgy to manufacture the valve body. Powder is loaded into a molding die, compacted, and then sintered and surface-treated to obtain the valve body. This ensures product consistency and effectively eliminates problems such as porosity, flow lines, and impurities present in existing casting processes. The resulting microstructure is finer, product quality is higher, and product dimensions are more precise. Less inorganic or mechanical processing is required, saving materials. Furthermore, it offers better impact resistance and a longer service life, ensuring the performance of the shock absorber. Additionally, by setting multiple bottom molds and lifting rollers that cooperate with each bottom mold on the frame, along with a pressurizing device and a top mold, the top mold selectively cooperates with a bottom mold to sequentially press and form multiple valve body molds. The lifting rollers then eject the pressed valve body molds from the bottom mold cavities and transfer them via a conveyor belt to the subsequent sintering mold. This improves processing efficiency and better meets the needs of large-scale valve body production. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the valve body processing technology of a piston assembly according to the present invention.

[0038] Figure 2 This is a simplified structural diagram of the valve body processing equipment for the piston assembly of the present invention from one perspective.

[0039] Figure 3 This is a simplified diagram showing the arrangement of the bottom mold and conveyor belt on the intermediate platform of the valve body processing equipment for the piston assembly of the present invention.

[0040] Figure 4 A simplified structural diagram of the bottom mold, top mold, lifting wheel, and reset assembly of the valve body processing equipment for the piston assembly of the present invention;

[0041] Figure 5 This is a simplified structural diagram of the bottom mold, top mold, lifting wheel, and reset assembly of the valve body processing equipment for the piston assembly of the present invention in another state.

[0042] Figure 6 This is a cross-sectional view of the bottom mold of the valve body processing equipment for the piston assembly of the present invention;

[0043] Figure 7 This is a simplified structural diagram of the transmission assembly of the valve body processing equipment for the piston assembly of the present invention.

[0044] In the attached diagram: 1. Frame; 11. Upper platform; 12. Middle platform; 2. Bottom mold; 21. Outer mold; 22. Base plate; 23. Telescopic rod; 24. Guide sleeve; 25. Deflection shaft; 211. Cavity; 212. Telescopic hole; 221. Concave hole; 231. Ball bearing; 2121. Guide hole; 2122. Swing hole; 2123. Guide groove; 3. Top mold; 31. Concave cavity; 32. Protruding column; 33. Positioning hole; 4. Pressurizing device; 41. Lower pressure rod; 5. Conveyor belt; 6. Lifting wheel; 7. Sliding drive assembly; 71. Drive screw; 72. Nut; 73. Sliding driver; 74. First reducer; 8. Transmission assembly; 81. Transmission shaft; 82. Drive shaft; 83. Second reducer; 84. Bevel gear transmission group; 9. Reset assembly; 91. Tension spring; 92. Limit block. Implementation

[0045] To make the technical means, creative features, objectives, and effects of this invention easier to understand, the following embodiments are provided in conjunction with the appendix. Figure 1 To be continued Figure 7 The technical solutions provided by this invention are described in detail, but the following content is not intended to limit this invention.

[0046] Figure 1 This is a flowchart illustrating the valve body manufacturing process of a piston assembly according to the present invention. Figure 1 As shown, the valve body processing technology of the piston assembly provided in this embodiment includes the following steps;

[0047] Step S1: Prepare raw material powder;

[0048] Multiple metal raw materials are crushed separately using mechanical crushing methods to produce various metal powders, which are then collected separately for later use.

[0049] Step S2, preparation of raw powder;

[0050] The different metal powders prepared in step S1 are mixed evenly according to a predetermined ratio. At this time, non-metallic raw material powders can be added as needed. Preferably, the metal powder raw materials for processing the valve body are tungsten carbide powder, titanium powder and molybdenum powder, and the mass percentages of each component are 80-85%, 10-15% and 8-12%, respectively. This makes the valve body obtained after subsequent processing stronger, more stable, less susceptible to impact damage, and has a longer service life. After mixing evenly, the blank powder used for processing is prepared.

[0051] Step S3, mold forming;

[0052] The raw powder prepared in step S2 is loaded into the molding mold. The molding mold is a combination structure of bottom mold 2 and top mold 3. Bottom mold 2 has a cavity 211. Top mold 3 moves with pressurizing device 4. During molding, raw powder is loaded into cavity 211 of bottom mold 2. At the same time, pressurizing device 4 is started to close top mold 3 and bottom mold 2 and apply pressure to press the raw powder in the molding mold into the mold body of valve body. The mold body of valve body after molding is taken out for use.

[0053] Step S4, sintering;

[0054] The valve body mold taken out in step S3 is placed into a graphite boat and transferred to a vacuum furnace for sintering. At this time, the temperature is rapidly raised to 1200-1300℃ within 3-5 minutes, and then held for 10-15 minutes. After completion, it is taken out to form the primary valve body.

[0055] Step S5, surface treatment;

[0056] The primary valve body formed in step S4 is placed in a steam environment for steam treatment to oxidize the surface of the primary valve body. An oxide film is then formed on the surface of the primary valve body, which improves its rust and corrosion resistance, resulting in a finished valve body and extending its service life.

[0057] It is worth noting that after step S4 is completed and before step S5 is performed, the operator needs to use a gauge to inspect the shape, size and flatness of the primary valve body. This ensures that the obtained primary valve body does not have defects such as deformation and meets the design requirements. If defects such as deformation occur, secondary processing is required in conjunction with shaping and machining processes to ensure the quality of the product.

[0058] Furthermore, a temperature measuring hole penetrating the wall is opened on the outer wall of the graphite boat used in step S4. At this time, a metal sleeve is provided for the temperature measuring hole, that is, the metal sleeve protects the hole wall of the temperature measuring hole of the graphite boat. At the same time, a removable metal plug is provided in the metal sleeve. That is, when temperature measurement is required, the metal plug is removed, and the temperature measuring components such as the temperature sensor are inserted into the graphite boat through the temperature measuring hole for detection. The operation is convenient. When not measuring temperature, the temperature measuring hole can be directly sealed by the metal plug to avoid excessive temperature loss from the temperature measuring hole, which would cause the problem of low sintering efficiency.

[0059] In addition, this embodiment also provides a processing equipment for the valve body of a piston assembly, used to prepare the mold of the valve body in step S3 of the above processing method. Figure 2 This is a simplified structural diagram of the valve body processing equipment for the piston assembly of the present invention from one perspective. Figure 3 This is a simplified diagram showing the arrangement of the bottom mold and conveyor belt on the intermediate platform of the valve body processing equipment for the piston assembly of the present invention. Figure 2 and Figure 3 As shown, the valve body processing equipment for the piston assembly provided in this embodiment includes: a frame 1, several bottom molds 2, a top mold 3, a pressurizing device 4, a conveyor belt 5, and several lifting wheels 6. The frame 1 serves as the carrier for installing the bottom molds 2, top molds 3, pressurizing device 4, conveyor belt 5, and lifting wheels 6.

[0060] Figure 4 A simplified structural diagram of the bottom mold, top mold, lifting wheel, and reset assembly of the valve body processing equipment for the piston assembly of the present invention; Figure 5 This is a simplified structural diagram of the bottom mold, top mold, lifting wheel, and reset assembly of the valve body processing equipment for the piston assembly of the present invention in another state. Figure 6 This is a cross-sectional view of the bottom mold of the valve body processing equipment for the piston assembly of the present invention. Figures 2 to 6 As shown, the frame 1 is placed on the ground. An upper platform 11 is located on the upper part of the frame 1, and an intermediate platform 12 is located in the middle of the frame 1. The upper platform 11 and the intermediate platform 12 are arranged parallel to each other and spaced apart, providing sufficient space between them to install structures such as the bottom mold 2, top mold 3, and conveyor belt 5. This also provides space for the movement of the top mold 3, conveyor belt 5, and other structures. Furthermore, placing the upper platform 11 above the intermediate platform 12 allows for the subsequent installation of the pressurizing device 4 via the upper platform 11 and the installation of the bottom mold 2 via the intermediate platform 12, enabling the pressurizing device 4 to act on the bottom mold 2.

[0061] Specifically, several bottom molds 2 are evenly and spaced on the intermediate platform 12. These bottom molds 2 are arranged along a straight line on the intermediate platform 12, allowing the pressurizing device 4 and conveyor belt 5 to be arranged in a straight line during subsequent mold closing and pressing of each bottom mold 2, as well as during the unloading of the pressed material. This results in a simpler stroke and facilitates structural layout and operation. Furthermore, each bottom mold 2 includes an outer mold 21 and a base plate 22. The bottom of the outer mold 21 is fixed to the intermediate platform 12, achieving stable installation of the outer mold 21 on the intermediate platform and providing stable support for the outer mold 21 during subsequent mold closing and pressing. Additionally, the outer mold 21 includes a cavity 211 with an upper opening. The cavity 211 is a cylindrical chamber, conforming to the outer contour shape of the valve body. This also facilitates the loading of raw material into the cavity 211 through the upper opening, making operation more convenient. In addition, a telescopic hole 212 is provided on the outer mold 21 and located at the center of the bottom wall of the cavity 211. A base plate 22 is coaxially disposed in the cavity 211, so that the base plate 22 can form the bottom of the cavity 211, providing conditions for sealing the telescopic hole 212 and bearing the blank powder. Furthermore, a telescopic rod 23 is provided at the bottom of the base plate 22, and the lower end of the telescopic rod 23 extends through the telescopic hole 212 to the bottom of the outer mold 21 and the intermediate platform 12. That is, by moving the telescopic rod 23 in the telescopic hole 212, the base plate 22 can be driven to move in the cavity 211. When the telescopic rod 23 rises, the base plate 22 pushes the mold of the pressed valve body out of the cavity 211, which facilitates the subsequent transfer to the graphite boat for sintering.

[0062] Specifically, the top mold 3 is positioned between the intermediate platform 12 and the upper platform 11. The top mold 3 selectively engages with a bottom mold 2, meaning it can be closed with a bottom mold 2 containing raw material powder as needed. During mold closing, the top mold 3 selectively extends into the cavity 211 of the corresponding bottom mold 2, and can slide within the cavity 211. Simultaneously, the bottom of the top mold 3 is provided with a recess 31 and a protrusion 32. During mold closing and pressing, the recess 31 on the top mold 3 forms a ring of protrusions on the end face of the resulting valve body mold, thus distinguishing the front and back of the valve body mold and providing conditions for ensuring the sintering direction in the subsequent process. Furthermore, a recess 221 corresponding to the protrusion 32 is provided on the base plate 22. When the top mold 3 is pressed into the cavity 211, the lower end of the protrusion 32 is inserted into the recess 221. That is, before the blank powder is loaded into the cavity 211, the protrusion 32 needs to be installed in the recess 221 of the base plate 22. This ensures that when pressing the mold of the valve body, the protrusion 32 can occupy the center position of the mold of the valve body, forming the central hole of the mold of the valve body through the protrusion 32, thus forming the outline structure of the valve body of the piston assembly and meeting the processing requirements. It is worth noting that when the base plate 22 pushes the mold of the valve body out of the cavity 211, the protrusion 32 can be removed first, preventing the problem of the mold of the valve body being difficult to remove from the base plate 22. In addition, to facilitate demolding, a release agent is applied to the inner wall of the cavity 211 of the outer mold 21, the top surface of the base plate 22, and the outer wall of the protrusion 32, which further facilitates the demolding operation of the molded valve body after pressing.

[0063] Specifically, the pressurizing device 4 is slidably mounted on the upper platform 11 along the arrangement direction of the bottom molds 2. That is, the pressurizing device 4 is installed on the upper platform 11 and can slide on the upper platform 11. The sliding direction of the pressurizing device 4 is the arrangement direction of the bottom molds 2, so that when the pressurizing device 4 slides, it can pass through each bottom mold 2 in sequence, providing a condition for the subsequent top mold 3 to selectively close with a bottom mold 2. At this time, the pressurizing device 4 has a vertically downward pressing rod 41. At the same time, the side of the top mold 3 away from the bottom mold 2 is fixedly installed on the pressing rod 41. That is, the top mold 3 can move with the pressurizing device 4 on the upper platform 11, so that the top mold 3 passes through the bottom molds 2 in sequence. At the same time, it can also move towards the bottom mold 2 under the action of the pressing rod 41 of the pressurizing device 4, so as to close with the bottom mold 2 below it and apply pressure to realize the pressing and molding of the blank powder in the cavity 211 to obtain the mold body of the valve body.

[0064] Specifically, the conveyor belt 5 is set on the intermediate platform 12, and the conveyor belt 5 is set along the arrangement direction of several bottom molds 2. The conveyor belt 5 is set on the side of the bottom mold 2 so that the mold of the valve body that is subsequently ejected from the bottom mold 2 can be transported out by the conveyor belt 5 on its side, which facilitates its subsequent placement in the graphite boat for sintering.

[0065] Specifically, several lifting wheels 6 are rotatably mounted below the intermediate platform 12, avoiding the problem of the lifting wheels 6 occupying the space above the intermediate platform 12. At this time, each lifting wheel 6 is a cam, that is, the distance from the wheel surface of the lifting wheel 6 to its axis changes linearly. In addition, one lifting wheel 6 corresponds to one bottom mold 2, and the wheel surface of the lifting wheel 6 contacts the lower end of the telescopic rod 23 installed on the bottom plate 22 of the corresponding bottom mold 2. This provides the conditions for the lifting wheel 6 to push the bottom plate 22 of the corresponding bottom mold 2 out of the cavity 211 through the telescopic rod 23 when the lifting wheel 6 rotates, thus facilitating demolding and material unloading.

[0066] More specifically, an electromagnet is embedded in the top mold 3. In this case, the protrusion 32 is made of a magnetically attractive metal, or a permanent magnet is embedded in the upper end of the protrusion 32. This achieves selective magnetic connection between the protrusion 32 and the top mold 3. After demolding, the operator can control the electromagnet to de-energize, making it easier to remove the protrusion 32 from the top mold 3 and place it in the recess 221 on the base plate 22. This provides the conditions for creating the center hole when pressing the valve body mold again, and also facilitates loading the blank powder. The molded part 211 is inserted into the mold cavity to facilitate the production of the central hole on the valve body mold. When the valve body mold is pressed and needs to be demolded, the top mold 3 rises with the pressure rod 41 of the pressurizing device 4. At this time, the electromagnet is activated so that the electromagnet attracts the protrusion 32 onto the top mold 3, thereby separating the protrusion 32 from the bottom plate 22. This allows the protrusion 32 to be pulled out from the central hole of the valve body mold pressed on the bottom plate 22, which solves the problem of the protrusion 32 blocking the movement of the valve body mold on the bottom plate 22 during subsequent demolding. Meanwhile, a flared positioning hole 33 is provided at the bottom of the top mold 3, and the positioning hole 33 is located at the center of the electromagnet. The flared positioning hole 33 facilitates the accurate and rapid entry of the upper end of the protrusion 32 into the positioning hole 33 when the top mold 3 is closed. The concave hole 221 and the positioning hole 33 restrict both ends of the protrusion 32, ensuring the stability of the protrusion 32 during mold closing and pressing, and ensuring higher quality of the mold body of the pressed valve body. It is worth noting that the distance from the bottom of the concave hole 221 to the bottom of the positioning hole 33 is greater than the length of the protrusion 32. Simultaneously, the length of the protrusion 32 is greater than the length of the center hole of the pressed valve body. This ensures that during the pressing of the valve body mold, initially, the lower end face of the protrusion 32 contacts the bottom of the concave hole 221 under its own weight, while the upper end face of the protrusion 32 does not contact the bottom of the positioning hole 33. This provides a certain feed margin for the top mold 3 to press. When pressing is completed and demolding is finished, the electromagnet can be activated first, i.e., the top mold 3 presses down on the valve body. In the case of the mold body, the protrusion 32 moves against gravity toward the top mold 3, so that the upper end face of the protrusion 32 contacts the bottom of the positioning hole 33, while the lower end face of the protrusion 32 separates from the bottom of the concave hole 221. This realizes the relative movement of the protrusion 32 with respect to the central hole of the mold body of the pressed valve body, which provides conditions for the protrusion 32 to be extracted from the central hole of the mold body of the pressed valve body more quickly. At the same time, it also prevents the risk of damage caused by excessive friction of the protrusion 32 against the central hole during demolding. The structural design is more reasonable.

[0067] More specifically, the pressurizing device 4 and the upper platform 11 are connected by a sliding drive assembly 7, which enables the pressurizing device 4 to slide on the upper platform 11. The sliding drive assembly 7 is positioned between the upper platform 11 and the pressurizing device 4. The sliding drive assembly 7 includes a drive screw 71, a nut 72, a sliding actuator 73, and a first reducer 74. Both ends of the drive screw 71 are rotatably mounted on the upper platform 11. The drive screw 71 is arranged along the sliding direction of the pressurizing device 4, meaning its arrangement direction is consistent with the arrangement direction of the bottom molds 2. The nut 72 is threaded onto the drive screw 71 and fixedly connected to the pressurizing device 4. When the drive screw 71 rotates, it drives the nut 72 to reciprocate along its axial direction, thus providing power for the sliding of the pressurizing device 4 on the upper platform 11. Furthermore, the drive screw 71 is powered by the first reducer 74, which in turn is powered by the sliding actuator 73. That is, the sliding actuator 73 drives the drive screw 71 to rotate via the first reducer 74. This not only provides driving force for the rotation of the drive screw 71 but also reduces speed, increases torque, and ensures the reliability of the drive. It is worth noting that a guide rail and a slider are provided between the pressurizing device 4 and the upper platform 11. The guide rail is arranged parallel to the drive screw 71 and fixed to the upper platform 11. The slider slides on the guide rail, and the pressurizing device 4 is mounted on the slider. The first reducer 74 may include, but is not limited to, a three-stage gear reducer, and the sliding actuator 73 may include, but is not limited to, an electric motor, as long as it meets the usage requirements.

[0068] Figure 7 This is a simplified structural diagram of the transmission assembly of the valve body processing equipment for the piston assembly of the present invention. Figure 2 and Figure 7 As shown, in order to drive the lifting wheel 6, a transmission component 8 is provided between the sliding drive component 7 and the lifting wheel 6. That is, the movement of the lifting wheel 6 is driven by the sliding drive 73 through the transmission component 8, so that the movement of the pressurizing device 4 and the rotation of the lifting wheel 6 are driven by the same sliding drive 73, which has higher coordination and more harmonious cooperation. At the same time, the use of drives is reduced, and the manufacturing and use costs are lower.

[0069] In addition, the transmission assembly 8 includes a transmission shaft 81, a drive shaft 82, a second reducer 83, and several sets of bevel gear transmission groups 84. The drive shaft 82 is rotatably mounted below the intermediate platform 12 in a direction parallel to the drive screw 71, and each lifting wheel 6 is fixedly sleeved on the drive shaft 82. That is, the synchronous installation of several lifting wheels 6 is achieved through one drive shaft 82, and the synchronous rotation of several lifting wheels 6 is also ensured, providing conditions to prevent confusion during subsequent material unloading. At this time, the transmission shaft 81 is set between the drive screw 71 and the drive shaft 82, and a set of bevel gear transmission groups 84 is respectively set between both ends of the transmission shaft 81 and the drive screw 71 and the drive shaft 82. That is, the drive screw 71 drives the transmission shaft 81 to rotate through the bevel gear transmission groups 84, and the transmission shaft 81 drives the drive shaft 82 to rotate through the bevel gear transmission groups 84, thus realizing the structural arrangement of the sliding actuator 73 driving the drive shaft 82 to rotate. Meanwhile, a second reducer 83 is connected to the drive shaft 82 before connecting to the corresponding bevel gear transmission group 84. Since the drive screw 71 and the sliding drive 73 have already been reduced in speed by the first reducer 74, the drive shaft 82 and the sliding drive 73 can be reduced in speed by the first reducer 74 and the second reducer 83. The speed reduction is more obvious, that is, the drive shaft 82 only rotates once after the drive screw 71 rotates multiple times. This ensures that the stroke settings of the pressurizing equipment 4 movement and the lifting wheel 6 rotation can meet the usage requirements, and the structural design is more reasonable.

[0070] More specifically, the protrusions of two adjacent lifting rollers 6 are staggered within the rotation plane of the lifting rollers 6 by an angle of 180°. That is, when the protrusion of the first lifting roller 6 contacts the lower end of the corresponding telescopic rod 23, the protrusion of the second lifting roller 6 separates from the corresponding telescopic rod 23. This achieves the staggered arrangement of the bottom plates 22 in the two bottom molds 2, allowing the other bottom mold 2 to unload material while one bottom mold 2 is pressing, thereby improving processing efficiency. It is worth noting that the loading process in the bottom mold 2 occurs before the top mold 3 moves above the corresponding bottom mold 2 and before pressing down. At this time, the bottom plate 22 in the bottom mold 2 moves to the lowest point of the cavity 211, ensuring that the space of the cavity 211 meets the pressing requirements of the valve body. Preferably, each lifting wheel 6 has a half-cam structure. That is, when the lifting wheel 6 rotates, if the lower end of the telescopic rod 23 passes the protrusion of the lifting wheel 6, the telescopic rod 23 will immediately move down, realizing the immediate reset of the top plate, thus providing sufficient time for the bottom mold 2 to load the blank powder, and the structural design is more reasonable.

[0071] More specifically, the expansion hole 212 on the bottom mold 2 is configured as a stepped hole. The larger diameter section of the expansion hole 212 is designated as the guide hole 2121, and the smaller diameter section is designated as the swing hole 2122. The guide hole 2121 and the swing hole 2122 are connected. Furthermore, the guide hole 2121 is located near the bottom plate 22, making it close to the cavity 211. Simultaneously, the depth of the guide hole 2121 is greater than the mold thickness of the valve body. This ensures that during subsequent material unloading, after the bottom plate 22 moves from the cavity 211 to the outer mold 21, the guide sleeve 24 sliding within the guide hole 2121 will disengage from the guide hole 2121. This ensures the stability of the bottom plate 22 during sliding within the cavity 211 and prevents damage to the bottom plate 22 and the inner wall of the cavity 211. In addition, the diameter of the swing hole 2122 is set to be larger than the diameter of the telescopic rod 23, which provides clearance for the swing movement of the telescopic rod 23 within the swing hole 2122. Meanwhile, two symmetrically arranged guide grooves 2123 are provided on the wall of the deflection hole 2122 along its axial direction. Furthermore, a guide sleeve 24 is provided on the bottom of the base plate 22, surrounding the telescopic rod 23, and slides within the guide hole 2121. That is, when the telescopic rod 23 rises or falls, the guide sleeve 24 slides within the guide hole 2121 and disengages from it. Simultaneously, a deflection shaft 25 is provided on the outer wall of the end of the telescopic rod 23 facing away from the base plate 22, extending radially through it. Both ends of the deflection shaft 25 extend into the two guide grooves 2123. That is, when the lifting wheel 6 rotates, the wheel surface of the lifting wheel 6 contacts the lower end of the telescopic rod 23 and gradually pushes the telescopic rod 23 upwards. Because the wheel surface of the lifting wheel 6 gradually protrudes linearly, when the lifting wheel 6 rotates, it not only provides a radial force to the telescopic rod 23, but also... A force is provided along the tangential direction of the lifting wheel 6. Therefore, when the guide sleeve 24 is in the guide hole 2121, due to the mutual restriction between the guide sleeve 24 and the guide hole 2121 and the restriction of the deflection shaft 25 in the guide groove 2123, the telescopic rod 23 cannot deflect and only moves upward. As the telescopic rod 23 gradually rises, the bottom plate 22 moves out of the cavity 211 and the guide sleeve 24 comes out of the guide hole 2121. At this time, the mutual restriction between the guide sleeve 24 and the guide hole 2121 disappears, so that the telescopic rod 23 can deflect about the deflection shaft 25 as the axis, thereby realizing the tilting of the bottom plate 22. Preferably, the tilting direction of the bottom plate 22 is the side where the conveyor belt 5 is arranged, so that the mold of the valve body pressed on the bottom plate 22 can slide onto the conveyor belt 5 and be transported to the subsequent sintering process by the conveyor belt 5, which has a higher degree of automation.

[0072] More specifically, the orifice of the guide hole 2121 is arranged in a flared shape at the end opposite to the swing hole 2122, so that when the lower end of the telescopic rod 23 passes the most protruding point of the lifting wheel 6, and the base plate 22, guide sleeve 24 and telescopic rod 23 are reset, the guide hole 2121 can accurately and quickly enter the guide hole 2121, thus providing conditions for the base plate 22 to smoothly enter the cavity 211.

[0073] More specifically, a reset assembly 9 is also provided between the telescopic rod 23 and the sway hole 2122. The reset assembly 9 includes a tension spring 91 and a limiting block 92. The two ends of the tension spring 91 are fixedly connected to the outer wall of the telescopic rod 23 and the hole wall of the sway hole 2122, respectively. At the same time, the tension spring 91 is arranged radially along the telescopic rod 23 and perpendicular to the deflection shaft 25. The tension spring 91 is located in the opposite direction of the rotation of the telescopic rod 23 relative to the lifting wheel 6, so that the direction of action of the tension spring 91 is exactly opposite to the sway direction of the telescopic rod 23. Thus, after the telescopic rod 23 rises and sways, the tension spring 91 can quickly pull the telescopic rod 23 to sway in the opposite direction and move it downward, thereby achieving rapid reset. Furthermore, a limit block 92 is provided on the wall of the sway hole 2122 and on the side of the telescopic rod 23 where the tension spring 91 is located. At the same time, when the telescopic rod 23 is vertically arranged, the limit block 92 contacts the outer wall of the telescopic rod 23, so that when the telescopic rod 23 automatically resets, the limit block 92 can prevent the telescopic rod 23 from excessively swaying, thereby preventing structural damage and making the structural design more reasonable.

[0074] More specifically, a ball bearing 231 is provided at the end of the telescopic rod 23 that contacts the wheel surface of the lifting wheel 6. Similarly, a ball bearing 231 is also provided at the end of the limiting block 92 that contacts the outer wall of the telescopic rod 23. The ball bearing 231 reduces frictional loss during mutual movement and extends service life.

[0075] The piston assembly valve body processing technology and equipment provided in this embodiment include the following steps: S1, preparing raw material powder; S2, preparing raw material powder; S3, molding; S4, sintering; and S5, surface treatment. By using powder metallurgy to manufacture the valve body, the raw material powder is pressed and sintered to form a primary valve body. The primary valve body is then surface treated to obtain the finished valve body. This ensures the consistency of the processed valve body, eliminates the problems of pores, flow lines, and excessive impurities, and results in a finer microstructure and higher quality. It also allows for more precise product molding dimensions, reduces or eliminates machining, saves materials, improves impact resistance, and extends service life, thus improving the performance of the shock absorber. In addition, by setting up a structure with a pressurizing device 4, a top mold 3, and a bottom mold 2, and cooperating with a lifting wheel 6 to lift and lower the bottom plate 22 in the bottom mold 2, the mold body can be automatically ejected and unloaded while meeting the mold pressing requirements of the valve body. This results in higher processing efficiency and adapts to the needs of large-scale valve body production.

[0076] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A valve body processing device for a piston assembly, characterized in that, The step S3 of the valve body machining process for the piston assembly is used, and the valve body machining process for the piston assembly includes the following steps: Step S1: Prepare raw material powder; The metal raw materials are crushed and made into metal powder; Step S2, preparation of raw powder; The different metal powders are mixed evenly in a predetermined ratio to prepare a blank powder; Step S3, mold forming; The raw powder is loaded into the molding die, and the pressurizing equipment is started to press the raw powder in the molding die into a mold body of the valve body; Step S4, sintering; The mold is placed in a graphite boat and transferred to a vacuum furnace for sintering to form a primary valve body; Step S5, surface treatment; The primary valve body is placed in a steam environment for steam treatment, and an oxide film is formed on the surface of the primary valve body to obtain the finished valve body. After step S4 and before step S5, a gauge is required to inspect the shape, size and flatness of the primary valve body. A temperature measuring hole penetrating the wall is provided on the outer wall of the graphite boat. The temperature measuring hole is provided with a metal sleeve, and a metal plug is provided in the metal sleeve. The valve body processing equipment for the piston assembly includes: A frame, wherein the frame is provided with an upper platform and an intermediate platform arranged parallel to each other and spaced apart, the upper platform being located above the intermediate platform; A plurality of bottom molds are evenly and spaced apart on the intermediate platform. The bottom molds are arranged along a straight line on the intermediate platform. Each bottom mold includes an outer mold and a bottom plate. The bottom of the outer mold is fixed to the intermediate platform and has a cavity with an upper opening. A telescopic hole is opened on the outer mold at the center of the bottom wall of the cavity. The bottom plate is disposed in the cavity, and a telescopic rod is provided at the bottom of the bottom plate, which passes through the telescopic hole and extends to the bottom of the outer mold and the intermediate platform. A top mold selectively engages with a bottom mold, the top mold selectively extends into the cavity and slides within the cavity, the bottom of the top mold is provided with a concave cavity and a protruding post, and the bottom plate is provided with a concave hole corresponding to the protruding post, and when the top mold is pressed into the cavity, the lower end of the protruding post is inserted into the concave hole; A pressurizing device is slidably mounted on the upper platform along the arrangement direction of the plurality of bottom molds. The pressurizing device has a vertically downward pressing rod, and the top mold is fixedly mounted on the pressing rod on the side opposite to the bottom mold. A conveyor belt is disposed on the intermediate platform and is arranged on the side of the bottom mold along the arrangement direction of the plurality of bottom molds; A plurality of lifting wheels are rotatably mounted below the intermediate platform. Each lifting wheel is a cam, and each lifting wheel corresponds to a bottom mold. The wheel surface of each lifting wheel is in contact with the lower end of the telescopic rod. The telescopic hole is a stepped hole. The larger diameter section of the telescopic hole is a guide hole, and the smaller diameter section is a swing hole. The guide hole is located on the side close to the base plate, and the depth of the guide hole is greater than the thickness of the valve body mold. The diameter of the swing hole is greater than the diameter of the telescopic rod. At the same time, two symmetrically arranged guide grooves are formed on the wall of the swing hole along its axial direction. A guide sleeve is provided on the bottom of the base plate and outside the telescopic rod. The guide sleeve slides in the guide hole. A deflection shaft is provided on the outer wall of the end of the telescopic rod away from the base plate, and the two ends of the deflection shaft extend into the two guide grooves respectively. It also includes a reset assembly, which includes a tension spring and a limiting block. The two ends of the tension spring are respectively fixedly connected to the outer wall of the telescopic rod and the wall of the deflection hole. The tension spring is arranged radially along the telescopic rod and is perpendicular to the deflection axis. At the same time, the tension spring is located in the opposite direction of the rotation of the telescopic rod relative to the lifting wheel. The limiting block is provided on the wall of the deflection hole and on the side of the telescopic rod where the tension spring is located. The limiting block contacts the outer wall of the telescopic rod when the telescopic rod is vertically arranged.

2. The valve body processing equipment for the piston assembly according to claim 1, characterized in that, An electromagnet is embedded in the top mold, and the protrusion is made of a metal that can attract magnetically or a permanent magnet is embedded at the upper end of the protrusion. Meanwhile, a positioning hole with an flared arrangement is opened at the bottom of the top mold, and the positioning hole is located at the center of the electromagnet.

3. The valve body processing equipment for the piston assembly according to claim 1, characterized in that, It also includes a sliding drive assembly, which is disposed between the upper platform and the pressurizing device. The sliding drive assembly includes a drive screw, a nut, a sliding actuator, and a first reducer. Both ends of the drive screw are rotatably mounted on the upper platform and arranged along the sliding direction with respect to the pressurizing device. The nut is threaded onto the drive screw and fixedly connected to the pressurizing device. Furthermore, the drive screw is poweredly connected to the first reducer, and the first reducer is poweredly connected to the sliding actuator.

4. The valve body processing equipment for the piston assembly according to claim 3, characterized in that, The system also includes a transmission assembly, which includes a transmission shaft, a drive shaft, a second reducer, and several sets of bevel gear transmission groups. The drive shaft is rotatably mounted below the intermediate platform in a direction parallel to the drive screw, and each lifting wheel is fixedly sleeved on the drive shaft. The transmission shaft is located between the drive screw and the drive shaft, and a set of bevel gear transmission groups is respectively provided between both ends of the transmission shaft and the drive screw and the drive shaft. In addition, the second reducer is connected to the drive shaft before connecting to the corresponding bevel gear transmission group.

5. The valve body processing equipment for the piston assembly according to claim 1, characterized in that, The protrusions of two adjacent lifting wheels are staggered from each other in the plane of rotation of the lifting wheels, and the staggered angle is 180°.

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