Cold extrusion processing method of inverting front shock absorber outer tube

Abstract

The application discloses a cold extrusion processing method of an inverted front shock absorber outer cylinder, and the flow is as follows: a blank pipe with thin wall thickness and greater length than that of the inverted front shock absorber outer cylinder product is adopted, then pressure is applied to both ends of the blank pipe, the blank pipe is gradually compressed in the length direction, under the restriction of the mandrel and the forming section of the cylindrical die cavity, the metal material constituting the blank pipe is in a flowing state and gradually fills the space between the mandrel and the forming section of the cylindrical die cavity, so that the blank pipe is formed into the required outer contour; compared with the current turning processing mode, the blank pipe adopted by the processing method is thin, the forming of the required outer contour does not need to be turned, the processing time is short, and the material waste is small; in addition, the processing method will not damage the metal fiber continuity of the blank pipe itself, and the extrusion forming can make the inverted front shock absorber outer cylinder product more compact and higher in strength.

Description

Technical Field

[0001] This invention belongs to the technical field of machining, specifically relating to a cold extrusion processing method for the outer cylinder of an inverted front shock absorber. Background Technology

[0002] Motorcycle front shock absorbers are divided into upright and inverted types. Upright front shock absorbers have a caliper seat for mounting the caliper and an axle hole for mounting the wheel at the lower end of the outer cylinder. They are manufactured using casting, but casting is prone to producing air bubbles and porosity, resulting in lower strength for the upright front shock absorber outer cylinder. Therefore, compared to inverted front shock absorbers, upright front shock absorbers are often larger and heavier for the same rigidity requirements. Inverted front shock absorbers, on the other hand, lack caliper seats and axle holes, and their outer contour is a tubular shape with a continuously changing outer diameter (see attached diagram). Figure 3 Therefore, turning is generally used. The forged billet tube is turned to obtain the required outer contour. The forged billet tube is more compact, so the inverted front shock absorber formed by turning has better strength than the cast front shock absorber. Under the same rigidity requirements, the inverted front shock absorber has a smaller size and weight, which is more conducive to vehicle handling.

[0003] To meet the requirements of turning, the blank tube needs to have sufficient machining allowance (i.e., greater than the maximum outer diameter of the finished product) outside the required outer contour. The wall thickness of the blank tube is much greater than the wall thickness at the minimum outer diameter of the finished product after machining, which will cause a lot of material waste in the entire machining process. Moreover, since the difference between the maximum and minimum outer diameters of the required outer contour is large, the machining of the required outer contour not only requires turning the blank tube multiple times, but also the surface is prone to defects such as tool marks and grooves after turning, which require further grinding. The time and labor costs of the entire machining process are high.

[0004] Therefore, it is necessary to design a machining method for the outer cylinder of the inverted front shock absorber that can reduce material waste and processing time. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a cold extrusion processing method for the outer cylinder of an inverted front shock absorber, which solves the technical problems of serious material waste and long processing time in the current processing of the outer cylinder of an inverted front shock absorber, and achieves the effect of reducing costs.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A cold extrusion processing method for an inverted front shock absorber outer cylinder, wherein the mold used in the cold extrusion processing method includes a die, a punch, and a mandrel; the die includes an upper die and a lower die, both of which have grooved cavities extending to both ends on their opposing surfaces; when the two sides of the upper and lower dies with grooved cavities are in contact, the two grooved cavities can form a columnar cavity; the middle part of the columnar cavity is a forming section, and the two ends are guide sections; the inner contour of the forming section matches the desired outer contour; the guide sections are equal-diameter sections and coaxial with the forming section; the inner diameter of the guide sections is less than or equal to the minimum inner diameter of the forming section; the length of the mandrel is greater than the length of the forming section, and the diameter of the mandrel is less than the inner diameter of the guide sections; the punch includes extrusion heads located at both ends of the die and in a tubular shape; the outer diameter of the extrusion heads matches the inner diameter of the guide sections and the extrusion heads can slide relative to each other within the guide sections; the length of the extrusion heads is greater than the guide sections; the inner diameter of the extrusion heads matches the diameter of the mandrel and the extrusion heads are sleeved on the outside of the mandrel and can slide relative to each other;

[0008] The cold extrusion processing method includes the following steps:

[0009] 1) Place the pre-made blank tube onto the mandrel and together they are placed inside the cylindrical mold cavity; the length of the blank tube is less than the length of the cylindrical mold cavity but greater than the length of the forming section, and both ends of the blank tube are located inside the two guide sections, while both ends of the mandrel extend outside the blank tube; the outer diameter of the blank tube matches the inner diameter of the guide section, and the inner diameter of the blank tube matches the diameter of the mandrel so that the cylindrical mold cavity, blank tube, mandrel, and two extrusion heads are all coaxial;

[0010] 2) The upper and lower dies are kept in contact by the pressure equipment to maintain the shape of the columnar mold cavity; the two extrusion heads move towards each other along the corresponding guide sections, respectively, and after they are respectively wrapped around the two ends of the mandrel that extend out of the billet tube, they continue to move towards each other and extrude the billet tube;

[0011] 3) The two extrusion heads stop moving towards each other, and the extrusion is completed; the billet tube is deformed by extrusion and fills the space between the mandrel and the forming section;

[0012] 4) Feeding.

[0013] Furthermore, the inner diameter of the guide section is equal to the minimum inner diameter of the forming section.

[0014] Furthermore, the length of the mandrel is greater than the length of the forming section but less than the length of the cylindrical mold cavity, and the diameter of the mandrel is less than the inner diameter of the guide section but equal to the inner diameter of the finished outer cylinder of the inverted front shock absorber.

[0015] Furthermore, the mandrel consists of a central block of the same length as the mandrel and two contour blocks. The central block has a large end face I and a small end face I along its length. Between the large end face I and the small end face I, there are four side faces I. Two opposite side faces I are inclined, and the other two opposite side faces I are arc surfaces with a radius equal to that of the mandrel. The contour blocks have a large end face II and a small end face II along their length. Between the large end face II and the small end face II, there are two side faces II. One side face II is inclined, and the other side face II is an arc surface with a radius equal to that of the mandrel. The two contour blocks are located on both sides of the central block. The large end face I and the two small end faces II form one end face of the mandrel, and the small end face I and the two large end faces II form the other end face of the mandrel. The two inclined side faces I on the contour blocks are respectively attached to the inclined side faces II on the two central blocks. The two arc surfaces I and the two side faces II form the outer circular surface of the mandrel.

[0016] In step 1), the center block and two contour blocks are assembled into a mandrel and pressed into the blank tube;

[0017] The blanking process described in step 4) involves fixing the blank tube and applying pressure toward the large end face I of the center block to disengage the center block from the blank tube, and then removing the two contour blocks from the blank tube.

[0018] Furthermore, the billet tube is made of 6061 aluminum alloy. Before step 1), the billet tube needs to be annealed. The annealing temperature is 410℃ and held for 2-3 hours. Then, it is cooled to room temperature in the heating furnace.

[0019] Further, in step 1), the blank tube is placed in the center of the groove-shaped mold cavity of the lower mold.

[0020] Furthermore, the pressure device includes a base and a frame fixed on the base. A hydraulic press is vertically mounted on the frame. The telescopic rod of the hydraulic press faces the base. An elastic element is connected to the end of the telescopic rod. An upper mounting seat is connected below the elastic element. A lower mounting seat is provided on the base directly opposite the upper mounting seat.

[0021] The machine frame is symmetrically equipped with vertically sliding pressure blocks on both sides of the hydraulic press. The pressure blocks are fixedly connected to the telescopic rod via pressure plates so that they can rise and fall vertically in sync with the telescopic rod. The machine base is equipped with a horizontally sliding pressure block opposite the pressure blocks. The upper end face of the pressure block and the lower end face of the pressure block are both inclined and matched. When the lower end face of the pressure block contacts the upper end face of the pressure block, the pressure block can be driven to slide towards the lower mounting base as the pressure block moves downward. A return spring is connected to one side of the pressure block. The force of the return spring on the pressure block drives the pressure block to slide away from the lower mounting base.

[0022] Furthermore, the elastic element is made of polyurethane rubber.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The cold extrusion processing method for the outer cylinder of the inverted front shock absorber described in this invention directly uses a blank tube with a thinner wall thickness and a length greater than that of the finished outer cylinder of the inverted front shock absorber. The blank tube is cold extruded to form the required outer contour. Compared with the current turning processing method, the blank tube required to manufacture a single finished product is lighter in weight, the required outer contour does not need to be turned, the processing time is short, and the material waste is less.

[0025] Furthermore, performance testing of cold-extruded products revealed that cold-pressed products exhibit higher strength compared to machined products! The reason for this is that, unlike turning, cold pressing does not disrupt the continuity of the metal fibers in the billet tube (leading to a decrease in the overall strength of the finished product). This method not only avoids disrupting the continuity of the metal fibers in the billet tube, but the extrusion molding also makes the outer cylinder of the inverted front shock absorber more compact and stronger. This allows for easier design of the part's volume or weight variations, achieving unexpected technical benefits.

[0026] 2. The cold extrusion processing method for the outer cylinder of the inverted front shock absorber described in this invention, through mold design, ensures that the inner diameter of the blank tube is consistent with the inner diameter of the finished outer cylinder of the inverted front shock absorber, and the outer diameter of the blank tube is consistent with the minimum outer diameter of the finished outer cylinder of the inverted front shock absorber. In this way, the wall thickness and extrusion deformation of the blank tube are small, which facilitates extrusion deformation and reduces the time consumption. By calculating and adjusting the length of the blank tube, it is achieved that when the required outer contour is obtained on the blank tube, the blank tube is just extruded to the same length as the forming section. The finished outer cylinder of the inverted front shock absorber is obtained in one step, thereby eliminating the need for subsequent turning, trimming and grinding processes, which can further reduce material waste and reduce manufacturing costs.

[0027] 3. In the cold extrusion processing method of the inverted front shock absorber outer cylinder of the present invention, the pressure equipment used realizes the conversion between vertical and horizontal movement through structural design. An elastic element is set between the end of the telescopic rod and the upper mounting seat, eliminating the conflict between the upper mounting seat and the extrusion head in the stroke. Thus, a single ordinary vertical hydraulic press can simultaneously provide the pressure required by the cold extrusion processing method of the present invention in three directions. Its structure is simple and the cost is low, which can effectively reduce the equipment cost required by the cold extrusion processing method. Attached Figure Description

[0028] Figure 1 This is a partial structural diagram of the mold used in the cold extrusion processing method described in the embodiment;

[0029] Figure 2 This is a half-sectional schematic diagram of the billet tube described in the embodiment;

[0030] Figure 3 This is a half-sectional schematic diagram of the finished inverted front shock absorber outer cylinder as described in the embodiment;

[0031] Figure 4 This is a schematic diagram of the combination of the pressure device and the mold described in the embodiment;

[0032] Figure 5 for Figure 4 A partial cross-sectional view of the blank tube placed at point A before processing;

[0033] Figure 6 for Figure 4 A cross-sectional view of the portion after the blank tube is inserted and processed at point A in the middle;

[0034] Figure 7 This is a schematic diagram of the structure of the existing three-dimensional pressure device described in the embodiment;

[0035] Figure 8 This is a front view of the mandrel described in the embodiment;

[0036] Figure 9 This is a left view of the mandrel described in the embodiment;

[0037] Figure 10 This is a right view of the mandrel described in the embodiment;

[0038] Among them, there are: 1. Cavity mold; 2. Upper mold; 3. Lower mold; 4. Extrusion head; 5. Mandrel; 51. Center block; 52. Contour block; 53. Large end face I; 54. Small end face I; 55. Large end face II; 56. Small end face II; 6. Columnar mold cavity; 7. Forming section; 8. Guide section; 9. Blank tube; 10. Finished product of inverted front shock absorber outer cylinder.

[0039] Machine base 11, machine frame 12, hydraulic press 13, telescopic rod 14, elastic element 15, upper mounting base 16, lower mounting base 17, pressure plate 18, pressure block 19, pressure receiving block 20, return spring 21. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0041] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Example:

[0043] Please see Figure 1A cold extrusion processing method for an inverted front shock absorber outer cylinder, wherein the mold used in the cold extrusion processing method includes a die 1, a punch, and a mandrel 5; the die 1 includes an upper die 2 and a lower die 3, both of which have grooved cavities extending to both ends, and the two sides of the upper die 2 and lower die 3 with grooved cavities can be tightly fitted together to form a columnar cavity 6, the two grooved cavities are symmetrical and are axially divided by the columnar cavity 6, the middle part of the columnar cavity 6 is a forming section 7, and the two ends are guide sections 8, the inner contour of the forming section 7 matches the size of the outer contour to be formed, the outer contour to be formed is the outer contour of the finished product, which can be machined by turning on a lathe. The outline of the die 1 is such that the cross-section of the inner outline of the forming section 7 is a circle and the center of each circle is on the same axis. The inner diameter of the guide section 8 is equal and coaxial with the forming section 7. The inner diameter of the guide section 8 is less than or equal to the minimum inner diameter of the forming section 7. The length of the mandrel 5 is greater than the length of the forming section 7 and less than the length of the cylindrical mold cavity 6. The diameter of the mandrel 5 is less than the inner diameter of the guide section 8. The mandrel 5 can be movably inserted into the cylindrical mold cavity 6. The punch includes a tubular extrusion head 4 located on both sides of the die 1. The outer diameter of the extrusion head 4 matches the inner diameter of the guide section 8. The inner diameter of the extrusion head 4 matches the diameter of the mandrel 5. The extrusion head 4 can slide along the corresponding side guide section 8.

[0044] Please see Figure 2 , Figure 3 , Figure 5 and Figure 6 The cold extrusion processing method includes the following steps:

[0045] 1) Fix the lower mold 3, place the pre-made blank tube 9 in the groove-shaped mold cavity of the lower mold 3, and make the two ends of the blank tube 9 respectively located in the corresponding areas of the two guide sections 8; the length of the blank tube 9 is less than the length of the columnar mold cavity 6 and greater than the length of the forming section 7, the outer diameter of the blank tube 9 matches the inner diameter of the guide section 8, and the inner diameter of the blank tube 9 matches the diameter of the mandrel 5; in this embodiment, the material of the blank tube 9 is 6061 aluminum alloy, and the blank tube 9 needs to be annealed before step 1). The annealing temperature is 410℃ and held for 2-3 hours, and then cooled to room temperature with the heating furnace;

[0046] 2) Insert the mandrel 5 into the blank tube 9, and make both ends of the mandrel 5 extend outside the blank tube 9;

[0047] 3) Place the upper mold 2 above the lower mold 3, and use a pressure device to keep the two sides of the upper mold 2 and the lower mold 3 with the grooved cavity tightly fitted;

[0048] 4) The two extrusion heads 4 are symmetrically arranged on both sides of the die 1 and coaxial with the guide section 8. The two extrusion heads 4 are pushed to move towards each other in a synchronous manner by the pressure device. The two extrusion heads 4 enter the corresponding side guide section 8 and gradually extrude the billet tube 9.

[0049] 5) After the two extrusion heads 4 move a certain distance towards each other, the blank tube 9 is compressed and deformed and completely fills the space between the mandrel 5 and the forming section 7, and the required outer contour is obtained on the blank tube 9.

[0050] 6) Reset the two extrusion heads 4, separate the upper die 2 and the lower die 3, remove the blank tube 9 with the desired outer contour and take out the mandrel 5 to complete the processing.

[0051] The cold extrusion processing method for the outer cylinder of the inverted front shock absorber described in this invention uses the aforementioned mold. In this method, the inner contour of the forming section 7 of the cylindrical cavity 6 in the die 1 matches the outer contour to be formed on the blank tube 9, for forming the required outer contour. The inner diameter of the guide section 8 is less than or equal to the minimum inner diameter of the forming section 7. During processing, the outer diameter of the blank tube 9 matches the inner diameter of the guide section 8, for installation and positioning of the blank tube 9, ensuring that the blank tube 9 remains coaxial with the cylindrical cavity 6, thus ensuring the blank tube 9 is properly positioned during processing. The coaxiality of the inner and outer contours after extrusion is ensured. In addition, the guide section 8 also guides the movement of the extrusion head 4. The diameter of the mandrel 5 is consistent with the inner diameter of the billet tube 9, providing support for the inner wall of the billet tube 9 and preventing the billet tube 9 from collapsing inward during the extrusion process. The outer diameter of the extrusion head 4 is consistent with the inner diameter of the guide section 8, and the inner diameter of the extrusion head 4 is consistent with the diameter of the mandrel 5. That is, the cross-section of the extrusion head 4 is consistent with the cross-section of the billet tube 9, so as to apply pressure to the end face of the billet tube 9 and avoid interference with the mandrel 5.

[0052] The main idea of ​​the cold extrusion processing method for the outer cylinder of the inverted front shock absorber described in this invention is as follows: a blank tube 9 with a thinner wall thickness and a length greater than that of the finished outer cylinder 10 of the inverted front shock absorber is used. Then, pressure is applied to both ends of the blank tube 9, and the blank tube 9 is gradually compressed in the length direction. Under the constraint of the mandrel 5 and the forming section 7 in the cylindrical mold cavity 6, the metal material constituting the blank tube 9 is in a fluid state and gradually fills the space between the mandrel 5 and the forming section 7 in the cylindrical mold cavity 6, thereby forming the required outer contour of the blank tube 9. Compared with the current turning processing method, the blank tube 9 used in this processing method is thinner, and the forming of the required outer contour does not require turning, the processing time is short, and the material waste is less. In addition, this processing method not only does not destroy the continuity of the metal fibers of the blank tube 9 itself, but the extrusion molding also makes the finished outer cylinder 10 of the inverted front shock absorber more compact and stronger.

[0053] To ensure that the mandrel 5 maintains support for the inner wall of the blank tube 9 throughout the extrusion process, the mandrel 5 needs to be in a state where it completely passes through the blank tube 9. Although step 1) states that the two ends of the blank tube 9 are located in the corresponding areas of the two guide sections 8, and step 2) states that both ends of the mandrel 5 extend outside the blank tube 9, if the blank tube 9 is biased to one side and the mandrel 5 is also biased to the same side before the extrusion begins, then in step 4), when the two extrusion heads 4 move towards each other, they will first push the blank tube 9 to the middle position. However, the mandrel 5 may not move with the blank tube 9 due to its own inertia, or the movement position may be short. This may result in the mandrel 5 not completely passing through the blank tube 9 after the blank tube 9 is centered, thus causing the extrusion process to fail. Therefore, to avoid this situation, in step 1), the blank tube 9 should be placed in the groove cavity of the lower die 3 as much as possible.

[0054] In this embodiment, the mandrel 5 consists of a central block 51 of the same length as the mandrel 5 and two contour blocks 52; the central block 51 has a large end face I 53 and a small end face I 54 along its length, and four side faces I are located between the large end face I 53 and the small end face I 54, two opposite side faces I are inclined, and the other two opposite side faces I are arc surfaces with a radius equal to that of the mandrel 5; the contour blocks 52 have a large end face II 55 and a small end face II 56 along their length. Between the large end face II 55 and the small end face II 56, there are two side faces II. One side face II is inclined, and the other side face II is an arc surface with a radius equal to that of the mandrel 5. Two contour blocks 52 are located on both sides of the center block 51. The large end face I 53 and the two small end faces II 56 form one end face of the mandrel 5, and the small end face I 54 and the two large end faces II 55 form the other end face of the mandrel 5. The two inclined side faces I on the contour block 52 are respectively attached to the inclined side faces II on the two center blocks 51. The two arc-shaped side faces I and the two side faces II form the outer circular surface of the mandrel 5. Correspondingly:

[0055] Step 1) includes assembling a mandrel from the center block and two contour blocks and pressing it into the blank tube;

[0056] Step 4) involves fixing the billet tube and applying pressure toward the large end face I of the center block to disengage the center block from the billet tube, and then removing the two contour blocks from the billet tube;

[0057] In this way, the mandrel 5 is divided into three parts and fitted with bevels so that the mandrel 5 can be easily removed after cold extrusion when it is tightly fitted with the blank tube 9.

[0058] In this embodiment, the inner diameter of the guide section 8 is equal to the minimum inner diameter of the forming section 7, and the diameter of the mandrel 5 is equal to the inner diameter of the finished outer cylinder 10 of the inverted front shock absorber. That is, the inner diameter of the blank tube 9 is limited to be consistent with the inner diameter of the finished outer cylinder 10 of the inverted front shock absorber, and the outer diameter of the blank tube 9 is consistent with the minimum outer diameter of the finished outer cylinder 10 of the inverted front shock absorber. In this way, the wall thickness and extrusion deformation of the blank tube 9 are small, which facilitates extrusion deformation and reduces the time consumption. In addition, the required length of the blank tube 9 can be calculated according to the size of the finished outer cylinder 10 of the inverted front shock absorber, so that when the required outer contour is obtained on the blank tube 9, the blank tube 9 is just extruded to the same length as the forming section 7. In this way, after the blank tube 9 is extruded, the finished outer cylinder 10 of the inverted front shock absorber can be directly formed. There is no need to machine the outer contour and inner wall, nor is it necessary to cut the edges and grind the ends. This can further reduce material waste and reduce manufacturing costs.

[0059] Correspondingly, it can be understood that the cold extrusion processing method for the outer cylinder of the inverted front shock absorber described in this invention can also meet different processing requirements by changing the size of the mold and the blank tube 9. When the finished outer cylinder 10 of the inverted front shock absorber has high requirements for the dimensional accuracy or surface roughness of the outer contour, the inner contour of the forming section 7 can be made slightly larger than the outer contour of the required forming, so as to leave a processing allowance for the precision turning and grinding of the outer contour. When the finished outer cylinder 10 of the inverted front shock absorber has high requirements for the dimensional accuracy or surface roughness of the inner diameter, the diameter of the mandrel 5 can be made smaller than the inner diameter of the finished outer cylinder 10 of the inverted front shock absorber, so as to leave a processing allowance for the precision turning and grinding of the inner diameter.

[0060] Please see Figure 4 In the cold extrusion processing method of the inverted front shock absorber outer cylinder of the present invention, the pressure equipment used includes a base 11 and a frame 12 fixed on the base 11. A hydraulic press 13 is vertically arranged on the frame 12. The telescopic rod 14 of the hydraulic press 13 faces the base 11. An elastic element 15 is connected to the end of the telescopic rod 14. An upper mounting seat 16 is connected below the elastic element 15. A lower mounting seat 17 is provided on the base 11 directly opposite the upper mounting seat 16.

[0061] The end of the telescopic rod 14 is connected to the elastic element 15 through the pressure plate 18. The lower end of the pressure plate 18 is fixedly connected to the pressure block 19. The base 11 is provided with a horizontally sliding pressure block 20 opposite to the pressure block 19. The upper end surface of the pressure block 20 is in contact with the lower end surface of the pressure block 19 and both are inclined surfaces. The pressure block 20 can slide horizontally toward the hydraulic press 13 as the pressure block 19 moves downward. A return spring 21 is connected to one side of the pressure block 20. The force of the return spring 21 on the pressure block 20 is in the direction away from the hydraulic press 13, so that the pressure block 20 can automatically return to its original position after the pressure block 19 moves upward after processing is completed.

[0062] Please see Figure 7Existing multi-directional pressure equipment generally has multiple hydraulic presses 13, which provide the required pressure in multiple directions respectively, such as... Figure 7 The three-dimensional pressure device shown;

[0063] Please see Figure 4 , Figure 5 and Figure 6 The pressure equipment of the present invention uses a hydraulic press 13 to simultaneously provide pressure in three directions required by the cold extrusion processing method of the present invention. Its structure is simple and the cost is low, which can effectively reduce the equipment cost required by the cold extrusion processing method.

[0064] First, during the extrusion process, the internal pressure on the upper die 2 and lower die 3 of the die 1 gradually increases. To ensure that the two sides of the upper die 2 and lower die 3 with grooved cavities remain tightly fitted, the telescopic rod 14 of the hydraulic press 13 applies a certain pressure to the upper die 2 through the upper mounting seat 16. Second, the telescopic rod 14 of the hydraulic press 13 is connected to the pressure block 19 through the pressure plate 18. The pressure block 19 and the pressure receiving block 20 abut against each other through the inclined surface. Under the guidance of the inclined surface, the vertical movement of the telescopic rod 14 of the hydraulic press 13 is converted into the lateral movement of the pressure receiving block 20. The pressure receiving blocks 20 on both sides synchronously push the two extrusion heads 4 to move towards each other to complete the extrusion of the billet tube 9. That is, one hydraulic press 13 provides pressure in three directions, but after the upper die 2 and lower die 3 are tightly fitted, the two... As the side extrusion head 4 begins to move laterally, to eliminate the conflict between the upper mounting base 16 and the extrusion head 4 in terms of stroke, an elastic element 15 is provided between the end of the telescopic rod 14 and the upper mounting base 16. In this way, when the hydraulic press 13 drives the extrusion head 4 to move laterally, the position of the upper mounting base 16 remains unchanged, and the elastic element 15 is gradually compressed and applies a gradually increasing downward pressure to the upper mounting base 16. Through the stroke of the extrusion head 4 moving laterally, and the pressure required by the extrusion head 4 at each position corresponding to the upper die 2, the elastic coefficient and size of the required elastic element 15 can be calculated. It can be designed as a helical compression spring. In this embodiment, the elastic deformation of the material itself is directly utilized, and the elastic element 15 is directly made of a columnar body of polyurethane rubber.

[0065] Correspondingly, in step 1), the lower mold 3 is located above the lower mounting base 17 and is fixedly connected to the lower mounting base 17; in step 3), the upper mold 2 is located below the upper mounting base 16 and is fixedly connected to the upper mounting base 16; in step 4), the end of the extrusion head 4 away from the die 1 is fixedly connected to the corresponding side pressure block 20.

[0066] In this embodiment, the frame 12 includes a plurality of vertical guide columns fixedly connected to the base 11 and a support plate fixedly connected to the upper end of each vertical guide column. The pressure source 13 is fixed on the support plate and its telescopic rod 14 passes downward through the support plate. The lower end of the telescopic rod 14 is connected to the pressure plate 18 through a sliding plate. The sliding plate is slidably connected to each vertical guide column to improve the stability of the vertical operation of the pressure plate 18. The pressure plate 18 is connected to the lower surface of the sliding plate, and each pressure block 19 is connected to the lower surface of the pressure plate 18.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A cold extrusion processing method of an inverted front shock absorber outer tube, characterized by: The mold used in the cold extrusion processing method comprises a concave die, a convex die and a mandrel; the concave die comprises an upper die and a lower die, and the opposite faces of the upper die and the lower die are provided with groove-shaped die cavities extending to both ends, and when the two faces of the upper die and the lower die are attached, the two groove-shaped die cavities form a columnar die cavity, the middle part of the columnar die cavity is a forming section, and both ends are guide sections, the inner contour of the forming section matches the outer contour of the required forming, the guide sections are equal-diameter sections and coaxial with the forming section, and the inner diameter of the guide section is less than or equal to the minimum inner diameter of the forming section; the length of the mandrel is greater than the length of the forming section, and the diameter of the mandrel is less than the inner diameter of the guide section; the convex die comprises extrusion heads in the form of tubes located at both ends of the concave die, the outer diameter of the extrusion head matches the inner diameter of the guide section, and the extrusion head can slide in the guide section, the length of the extrusion head is greater than the guide section, the inner diameter of the extrusion head matches the diameter of the mandrel, and the extrusion head is sleeved on the outer side of the mandrel and can slide relative to the mandrel; The cold extrusion processing method comprises the following steps: 1) The pre-prepared blank pipe is sleeved on the mandrel and placed in the columnar die cavity; the length of the blank pipe is less than the length of the columnar die cavity and greater than the length of the forming section, both ends of the blank pipe are located in the two guide sections respectively, and both ends of the mandrel extend out of the blank pipe; the outer diameter of the blank pipe matches the inner diameter of the guide section, and the inner diameter of the blank pipe matches the diameter of the mandrel so that the columnar die cavity, the blank pipe, the mandrel and the two extrusion heads are coaxial; 2) The pressure equipment is used to keep the upper die and the lower die attached to keep the shape of the columnar die cavity; the two extrusion heads move towards each other along the corresponding guide sections, continue to move towards each other after the two ends of the mandrel extending out of the blank pipe are sleeved, and extrude the blank pipe; 3) The two extrusion heads stop moving towards each other, and the extrusion is completed; the blank pipe is deformed and filled with the space between the mandrel and the forming section; 4) Discharging; The mandrel is composed of a center block with the same length as the mandrel and two profile blocks; the center block has a large end face I and a small end face I along the length direction, and has four side faces I between the large end face I and the small end face I, two opposite side faces I are inclined surfaces, and the other two opposite side faces I are circular arc surfaces with a radius equal to that of the mandrel; the profile block has a large end face II and a small end face II along the length direction, and has two side faces II between the large end face II and the small end face II, one side face II is an inclined surface, and the other side face II is a circular arc surface with a radius equal to that of the mandrel; the two profile blocks are located on both sides of the center block, the large end face I and the two small end faces II form one end face of the mandrel, the small end face I and the two large end faces II form the other end face of the mandrel, the two side faces I of the profile block that are inclined surfaces are attached to the side faces II of the two center blocks that are inclined surfaces respectively, and the two side faces I and the two side faces II that are circular arc surfaces form the outer circular surface of the mandrel; In step 1), the center block and the two profile blocks are combined into the mandrel and pressed into the blank pipe; In step 4), the discharging comprises fixing the blank pipe, applying pressure to the small end face I of the center block towards the large end face I to make the center block separate from the blank pipe, and then taking out the two profile blocks from the blank pipe; The pressure device comprises a base, a frame fixed on the base, an oil press vertically arranged on the frame, an extension rod of the oil press facing the base, an elastic element connected to the end of the extension rod, an upper mounting seat connected below the elastic element, and a lower mounting seat arranged on the base opposite to the upper mounting seat; Symmetrically arranged on both sides of the oil press on the frame are pressure blocks vertically slidable, the pressure blocks being fixedly connected with the extension rod through a pressing plate to vertically ascend and descend synchronously with the extension rod, the base being provided with a pressure-receiving block opposite to the pressure blocks and horizontally slidable, the upper end surface of the pressure-receiving block and the lower end surface of the pressure block being both inclined and matched, the lower end surface of the pressure block being in contact with the upper end surface of the pressure-receiving block, and the pressure-receiving block being driven to slide towards the lower mounting seat when the pressure block moves downwards; one side of the pressure-receiving block is connected with a return spring, and the force of the return spring drives the pressure-receiving block to slide away from the lower mounting seat.

2. The cold extrusion method of claim 1, wherein: The inner diameter of the guide section is equal to the minimum inner diameter of the forming section.

3. The cold extrusion method of claim 1, wherein: The length of the mandrel is greater than the length of the forming section and less than the length of the cylindrical mold cavity, the diameter of the mandrel is less than the inner diameter of the guide section and equal to the inner diameter of the inverted front shock absorber outer cylinder product.

4. The cold extrusion method of claim 1, wherein: The material of the blank pipe is 6061 aluminum alloy, and the blank pipe needs to be annealed before step 1), the annealing temperature is 410 DEG C and the temperature is kept for 2-3 hours, and then the blank pipe is cooled to room temperature with the heating furnace.

5. The cold extrusion method of claim 1, wherein: In step 1), the blank pipe is centrally arranged in the groove-shaped mold cavity of the lower mold.

6. The cold extrusion method of inverting a front shock absorber outer tube according to claim 1, characterized by: The material of the elastic element is polyurethane rubber.

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