Press-fitting method and press-fitting tooling for two-section jacket-type lightweight axle box pivot node

Abstract

The present invention discloses a press-fitting method and press-fitting tooling for a two-section sleeve-type lightweight axle box pivot arm node, wherein the press-fitting method is to install a snap ring at the gap between the rubber joint 1 and the rubber joint 2 of the two-section sleeve-type lightweight axle box pivot arm node before press-fitting, and during the press-fitting process, the rubber joint 1, the rubber joint 2 and the snap ring are formed into an integral structure by using the effect of pressure, so that the rubber joint 2 located at the lower position is pressed into the node mounting hole, and then the press-fitting is stopped, the snap ring is first removed, and then the pressure is continued, and finally the rubber joint 1 located at the upper position is also pressed into the node mounting hole, thereby completing the press-fitting work. When the present invention press-fits the two-section sleeve-type lightweight axle box pivot arm node, the outer peripheral surface of the metal sleeve of the node and the inner peripheral surface of the node mounting hole of the pivot arm will not be scratched, thereby meeting the maintenance requirements and ensuring that there is sufficient interference press-fitting force between the mating surfaces.

Description

Technical Field

[0001] The present invention relates to a press-fitting method and a press-fitting tool for an axle box pivot arm node, and in particular to a press-fitting method and a press-fitting tool for a two-section outer sleeve type lightweight axle box pivot arm node. Background Art

[0002] As rail vehicle speeds increase, new requirements are placed on the performance and reliability of vehicle running gear, leading to the adoption of a wide range of new structures in bogies. Among these, the axlebox pivoting arm positioning method, with its compact structure, reliable performance, and lack of wear parts, has been widely used in high-speed EMU and urban rail vehicle bogies.

[0003] The arm rubber node is a key component in the axle box arm device, and its reliability is the guarantee of driving safety. Figure 1 As shown, an axle box pivot arm device includes a pivot arm 1 and a pivot arm node 2. A node mounting hole 3 is formed at one end of the pivot arm 1, and the pivot arm node 2 is press-fitted into the node mounting hole 3. During maintenance, the pivot arm node 2 needs to be withdrawn from the node mounting hole 3 of the pivot arm 1. After the maintenance is completed, the pivot arm node 2 needs to be press-fitted into the node mounting hole 3 of the pivot arm 1 again.

[0004] The rail transit industry is developing in a green and intelligent direction, and lightweighting is becoming a trend in future rail vehicles. As a crucial component of rail vehicles, bogies play a vital role in driving safety, ride comfort, and stability. Reducing bogie weight is crucial for overall rail vehicle lightweighting. In this context, corresponding lightweighting treatments have been applied to tumbler rubber joints. For example, a lightweight axlebox tumbler joint features an outer sleeve made of aluminum alloy.

[0005] There are many types of boom joints, including a two-section jacket-type lightweight axle box boom joint, such as Figure 2 As shown, the two rubber joints are vulcanized and bonded to the core shaft 4. They provide longitudinal stiffness for the axlebox and, together with the primary springs, provide primary lateral stiffness, transmitting the longitudinal and lateral forces between the wheelset and the frame. The two rubber joints include rubber joint 1 5 and rubber joint 2 6. The outermost metal jacket of each rubber joint is made of aluminum alloy.

[0006] A problem with the existing technology is that, due to the relatively soft aluminum alloy, press-fitting the two-section, jacket-type lightweight axlebox pivot joint often scratches the metal jacket of the rubber joint, resulting in scratches on the outer surface, and also scratches on the inner surface of the pivot joint mounting hole. This problem is not permitted by maintenance requirements. In addition, since the joint is press-fitted into the mounting hole by interference fit, scratches on the mating contact surface will reduce the interference fit force, causing the joint to move up and down during operation, ultimately affecting the performance of the bogie.

[0007] After searching, no patent documents identical or similar to this application have been found.

[0008] In summary, how to design a press-fitting method and press-fitting tooling for a two-section sleeve-type lightweight axle box pivot arm node so that when the two-section sleeve-type lightweight axle box pivot arm node is pressed, the outer peripheral surface of the metal sleeve of the node and the inner peripheral surface of the node mounting hole of the pivot arm are not scratched, the maintenance requirements are met, and sufficient interference pressing force is ensured between the mating surfaces, and the node is prevented from moving up and down during operation, and ultimately the performance of the bogie is ensured. This is a technical problem that needs to be solved urgently. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to address the defects existing in the prior art and provide a press-fitting method and press-fitting tooling for a two-section sleeve-type lightweight axle box pivot arm node. When the two-section sleeve-type lightweight axle box pivot arm node is press-fitted, the outer peripheral surface of the metal sleeve of the node and the inner peripheral surface of the node mounting hole of the pivot arm will not be scratched, thereby meeting the maintenance requirements and ensuring that there is sufficient interference pressing force between the mating surfaces, preventing the node from moving up and down during operation, and ultimately ensuring the performance of the bogie.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is: a press-fitting method for a two-section sleeve-type lightweight axle box pivot arm node, which is to place the two-section sleeve-type lightweight axle box pivot arm node above the node mounting hole of the pivot arm, and then vertically press the two-section sleeve-type lightweight axle box pivot arm node into the node mounting hole of the pivot arm. Before press-fitting, a snap ring is first installed in the gap between the rubber joint 1 and the rubber joint 2 of the two-section sleeve-type lightweight axle box pivot arm node. During the press-fitting process, the effect of pressure is used to form an integral structure between the rubber joint 1, the rubber joint 2 and the snap ring, so that the rubber joint 2 located at the lower position is pressed into the node mounting hole, and then the press-fitting is stopped, the snap ring is first removed, and then pressure is continued, and finally the rubber joint 1 located at the upper position is also pressed into the node mounting hole, thereby completing the press-fitting work.

[0011] Preferably, the snap ring includes an arc-shaped snap ring 1 and an arc-shaped snap ring 2. When the snap ring is inserted into the gap between the rubber joint 1 and the rubber joint 2, a gap 1 is left between the opposite ends of the arc-shaped snap ring 1 and the arc-shaped snap ring 2.

[0012] When the snap ring needs to be removed, a tool is inserted into the gap one to pry out the arc-shaped snap ring one and the arc-shaped snap ring two.

[0013] Preferably, before press-fitting, the corners of the metal jackets of the rubber joint 1 and the rubber joint 2 are chamfered, and the corners of the node mounting hole at one end of the rotating arm are chamfered.

[0014] Preferably, before press-fitting, lubricant is applied to the outer peripheral surfaces of the metal jackets of the rubber joint 1 and the rubber joint 2.

[0015] Preferably, the lubricant is applied on the metal jacket of each rubber joint from bottom to top, and the applied length does not exceed one third of the length of the metal jacket.

[0016] Preferably, the press speed is set to 50 to 100 mm / min.

[0017] Preferably, the press-fitting process is completed on a press-fitting tool;

[0018] The press-fitting tool comprises a base plate, a supporting cylinder 1 and a supporting cylinder 2 arranged on the base plate, a positioning cylinder is slidably connected inside the supporting cylinder 2, the bottom of the positioning cylinder is supported on the base plate by a spring inside the supporting cylinder 2, a positioning groove 1 is provided on the top of the positioning cylinder that matches one end of the core shaft of the node, the press-fitting tool also comprises a pressing head, the top of the pressing head is connected to the press, and a positioning groove 2 is provided on the bottom surface of the pressing head that matches the other end of the core shaft of the node, and the central axis of the pressing head coincides with the central axis of the positioning cylinder and the supporting cylinder 2;

[0019] When press-fitting, place one end of the swing arm on the top of the cylinder of the support cylinder 2, so that the positioning cylinder is located inside the node mounting hole on one end of the swing arm and the center axis of the node mounting hole coincides with the center axis of the positioning cylinder, and place the other end of the swing arm on the support cylinder 1. After placement, the swing arm is in a horizontal state; then place the two-section outer sleeve type lightweight axle box swing arm node with a snap ring vertically on the positioning cylinder, so that one end of the node's core shaft is located in the positioning groove 1, and then control the press to drive the pressure head to move downward, so that the other end of the node's core shaft is inserted into the positioning groove 2, and finally control the pressure head to press down, first press the rubber joint 2 into the node mounting hole, and then remove the snap ring, and continue to control the pressure head to press down until the rubber joint 1 is also pressed into the node mounting hole, and the press-fitting work is completed.

[0020] Preferably, during the press-fitting operation, the press-fitting stroke is controlled by adjusting the distance the press-fitting head moves downward when the bottom of the press-fitting head contacts the top of the cylinder body of the second supporting cylinder.

[0021] The present invention also discloses a press-fitting tool, the press-fitting tool comprising a bottom plate, a first supporting tube and a second supporting tube arranged on the bottom plate, a positioning tube being slidably connected inside the second supporting tube, the bottom of the positioning tube being supported on the bottom plate by a spring inside the second supporting tube, a first positioning groove matching one end of the core shaft of the node being provided on the top of the positioning tube, the press-fitting tool further comprising a pressing head and a retaining ring, the top of the pressing head being connected to the press, a second positioning groove matching the other end of the core shaft of the node being provided on the bottom surface of the pressing head, the central axis of the pressing head being coincident with the central axes of the positioning tube and the second supporting tube;

[0022] The clamping ring can be detachably clamped into the gap between the first rubber joint and the second rubber joint of the two-section sleeve-type lightweight axle box swing arm nodes before press-fitting.

[0023] Preferably, a composite material layer is provided on the outer peripheral surface of the positioning cylinder.

[0024] The beneficial effects of the present invention are as follows: in the first half of the press-fitting, the present invention forms an integral structure between the rubber joint 1, the rubber joint 2 and the snap ring by adding a snap ring, so that the force on the rubber joint 1 and the rubber joint 2 is uniform, and the tilting of the rubber joint 1 located at the upper position is avoided; before the second half of the press-fitting, the snap ring is first removed, and then the press-fitting work is continued. Through the above-mentioned press-fitting method, when the present invention press-fits the two-section jacket-type lightweight axle box pivot arm node, the outer peripheral surface of the metal jacket of the node and the inner peripheral surface of the node mounting hole of the pivot arm will not be scratched, which meets the maintenance requirements and ensures that there is sufficient interference press-fitting force between the mating surfaces, and prevents the node from moving up and down during operation, ultimately ensuring the performance of the bogie. The snap ring is designed as a split structure and a gap 1 is reserved between the two split snap rings after installation, so that the snap ring can be easily taken out through the gap 1. By rounding the corners, the problem of scratching the outer peripheral surface of the metal jacket of the node and the inner peripheral surface of the node mounting hole of the pivot arm can be further avoided. By applying appropriate lubricants, the problem of scratches on the outer circumference of the node's metal jacket and the inner circumference of the node mounting hole of the pivot arm can be further solved, and sufficient interference fit force can be ensured after the node is installed, so that the node will not move up or down during operation. By designing a press-fitting tool, the positioning structure of the positioning groove 1 of the positioning cylinder of the tool and the positioning groove 2 of the pressure head and the positioning structure of the pressure head are aligned with the central axis of the positioning cylinder and the supporting cylinder 2, thereby ensuring that the press can apply vertical pressure to the end face of the metal jacket, thereby further avoiding the occurrence of scratches. By providing a composite material layer on the outer circumference of the positioning cylinder, scratches on the inner circumference of the node mounting hole of the pivot arm are further avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the three-dimensional structure of an axle box rotating arm device;

[0026] Figure 2 This is a schematic diagram of the main structure of a two-section jacket-type lightweight axle box swing arm node;

[0027] Figure 3 Theoretically, the principle structure diagram of the press-fitting of the two-section jacket-type lightweight axle box arm node Figure 1 ;

[0028] Figure 4 Theoretically, the principle structure diagram of the press-fitting of the two-section jacket-type lightweight axle box arm node Figure 2 ;

[0029] Figure 5 Theoretically, the principle structure diagram of the press-fitting of the two-section jacket-type lightweight axle box arm node Figure 3 ;

[0030] Figure 6Theoretically, the principle structure diagram of the press-fitting of the two-section jacket-type lightweight axle box arm node Figure 4 ;

[0031] Figure 7 Theoretically, the principle structure diagram of the press-fitting of the two-section jacket-type lightweight axle box arm node Figure 5 ;

[0032] Figure 8 This is a schematic diagram of the principle structure of the press-fitting of the two-section jacket-type lightweight axle box arm node in the actual working process. Figure 1 ;

[0033] Figure 9 This is a schematic diagram of the principle structure of the press-fitting of the two-section jacket-type lightweight axle box arm node in the actual working process. Figure 2 ;

[0034] Figure 10 This is a schematic diagram of the principle structure of press-fitting two-section sleeve-type lightweight axle box pivot node in an embodiment of the present invention;

[0035] Figure 11 Schematic diagram of the axial cross-sectional structure of the snap ring in an embodiment of the present invention;

[0036] Figure 12 This is a schematic diagram of a partial axial cross-sectional structure at the clamping ring after the clamping ring is clamped into the gap between the first rubber joint and the second rubber joint in an embodiment of the present invention;

[0037] Figure 13 This is a schematic diagram of the axial cross-sectional structure of the press-fitting tooling in an embodiment of the present invention;

[0038] Figure 14 This is a schematic diagram of the axial cross-sectional structure of the positioning cylinder in an embodiment of the present invention;

[0039] In the figure: 1. pivot arm, 2. pivot arm node, 3. node mounting hole, 4. core shaft, 5. rubber joint 1, 6. rubber joint 2, 7. snap ring, 71. arc snap ring 1, 72. arc snap ring 2, 8. gap 1, 9. arc bottom plate, 10. arc side wall, 11. gap 2, 12. bottom plate, 13. support cylinder 1, 131. step portion, 14. support cylinder 2, 141. cylinder top, 142. slide 1, 143. slide 2, 15. positioning cylinder, 151. positioning groove 1, 152. slider 1, 153. slider 2, 16. spring, 17. pressure head, 171. positioning groove 2, 18. insert 1, 19. insert 2, 20. composite material layer, 21. mounting hole, 22. ball bearing. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example: To solve the problem of scratches on the outer circumference of the metal jacket of the node and the inner circumference of the node mounting hole of the rotating arm, the applicant has made improvements in the following aspects, which are described below:

[0042] 1. In theory, the press-fitting process is: first place the two-section jacket-type lightweight axle box arm node 2 above the node mounting hole 3 at one end of the arm 1 (such as Figure 3 As shown), then a downward pressure F is applied to the two-section jacket-type lightweight axle box arm node 2. Under the action of the pressure F, the rubber joint 2 6 at the lower position of the two-section jacket-type lightweight axle box arm node 2 first enters the node mounting hole 3 (as shown). Figure 4 and Figure 5 As shown), then the rubber joint 5 at the upper position of the two-section jacket-type lightweight axle box arm node 2 enters the node mounting hole 3 (as shown Figure 6 As shown), finally, when the press is in place, the rubber joint 1 5 and the rubber joint 2 6 of the two-section jacket-type lightweight axle box arm node 2 are all pressed into the node installation hole 3 (as shown Figure 7 shown).

[0043] However, the applicant found through research that Figure 8 As shown in the figure, during the actual press-fitting process, the rubber joint 15 located at the upper position of the two-section sleeve-type lightweight axle box arm node 2 will tilt and deform, so that the central axis L2 of the rubber joint 15 and the central axis L1 of the node core shaft 4 do not coincide with each other, but intersect to form an angle. Figure 9 As shown, when the rubber joint 1 5 enters the node mounting hole 3 , the tilted metal jacket of the rubber joint 1 5 will scratch the inner circumference of the node mounting hole 3 , and accordingly, the metal jacket of the rubber joint 1 5 will also be scratched.

[0044] Further research revealed that the tilting and deformation of rubber joint 1 (5) at the top occurs primarily because the press applies pressure gradually, i.e., the pressure F gradually increases. During the initial half of the press, the pressure F is less than the node gap closing force N. Therefore, under the action of pressure F, rubber joint 1 (5) and rubber joint 2 (6) do not contact each other, and the forces acting on them are uneven. Rubber joint 2 (6) at the bottom, because it can immediately enter the node mounting hole 3, does not tilt. However, rubber joint 1 (5) at the top is farther away from the node mounting hole 3 during the first half of the press-fitting process and, having not yet entered the node mounting hole 3, tilts, causing scratches on the outer circumference of the rubber joint's metal jacket and the inner circumference of the node mounting hole during the second half of the press-fitting process. The node gap closing force N is the force required to eliminate the gap H between rubber joint 1 (5) and rubber joint 2 (6) of the two-section jacket-type lightweight axle box pivot node 2, closing them together.

[0045] The applicant's pressing method is: Figure 10 As shown, before press-fitting, a snap ring 7 is first installed in the gap H between the rubber joint 1 5 and the rubber joint 2 6 of the two-section sleeve-type lightweight axle box arm node 2, and then press-fitting is carried out. At this time, under the action of pressure F, the rubber joint 1 5, the rubber joint 2 6 and the snap ring 7 form an integral structure. Although the pressure F is still less than the node gap width closing force N during the first half of the press-fitting process, the integral structure formed between the rubber joint 1 5, the rubber joint 2 6 and the snap ring 7 makes the force on the rubber joint 1 5 and the rubber joint 2 6 uniform, thus preventing the rubber joint 1 5 located at the upper position from tilting. Figure 5 As shown, after the lower rubber joint 6 is pressed into the node mounting hole 3, the snap ring 7 is removed and the press-fitting process continues, ultimately completing the press-fitting process. After the lower rubber joint 6 is pressed into the node mounting hole 3, the upper rubber joint 1 5 is already very close to the node mounting hole 3. Therefore, during the subsequent second half of the press-fitting process, the rubber joint 1 5 can be quickly pressed into the node mounting hole 3. Consequently, the rubber joint 1 5 will not tilt during the subsequent press-fitting process, ensuring that the rubber joint 1 5 can also vertically enter the node mounting hole 3, thereby preventing scratches.

[0046] Through the above-mentioned pressing method, when this embodiment presses the two-section sleeve-type lightweight axle box arm node, the outer peripheral surface of the node's metal sleeve and the inner peripheral surface of the node mounting hole of the arm will not be scratched, which meets the maintenance requirements and ensures that there is sufficient interference pressing force between the mating surfaces, preventing the node from moving up and down during operation, and ultimately ensuring the performance of the bogie.

[0047] The illustrated snap ring 7 comprises an arcuate snap ring 1 71 and an arcuate snap ring 2 72. When snap ring 7 is inserted into the gap H between rubber joint 1 5 and rubber joint 2 6, a gap 8 is left between the opposing ends of arcuate snap ring 1 71 and arcuate snap ring 2 72. The split design of the snap ring and the reserved gap 8 facilitate the operator's removal of snap ring 7.

[0048] like Figure 11 As shown, the axial cross-section of the arc-shaped snap ring 1 71 and the arc-shaped snap ring 2 72 is L-shaped, including an arc-shaped bottom plate 9 and an arc-shaped side wall 10 provided on one end of the arc-shaped bottom plate 9, as shown in FIG. Figure 10 and Figure 12 As shown, the thickness D of the arcuate bottom plate 9 is less than the gap H between the rubber joint 1 5 and the rubber joint 2 6. Before press-fitting, after the snap ring 7 is inserted into the gap H, the arcuate bottom plates 9 of the arcuate snap ring 1 71 and the arcuate snap ring 2 72 are placed on the top surface of the rubber joint 2 6, and a gap 211 is left between the arcuate bottom plates 9 of the arcuate snap ring 1 71 and the arcuate snap ring 2 72 and the rubber joint 1 5. When pressurization begins, under the action of the pressure F, the rubber joint 1 5 presses the arcuate bottom plate 9 against the rubber joint 2 6, thereby forming an integral structure between the rubber joint 1 5, the rubber joint 2 6, and the snap ring 7. When the snap ring 7 needs to be removed, a tool such as a screwdriver or a crowbar is inserted into the gap 8 between the arcuate snap ring 1 71 and the arcuate snap ring 2 72 to pry them out. The press is then controlled to continue applying pressure, and finally the two-section sleeve-type lightweight axle box pivot node 2 is press-fitted. When removing the snap ring 7, the press can be depressurized first and then removed, or the snap ring 7 can be directly removed while maintaining the pressure.

[0049] Second, to further prevent scratches, the applicant also rounded the corners of the metal jackets of rubber joint 1 5 and rubber joint 2 6 before press-fitting, as well as the corners of the node mounting hole 3 at one end of the swing arm 1. This rounding further prevents scratches on the outer circumference of the node's metal jacket and the inner circumference of the node mounting hole in the swing arm.

[0050] Third, to further prevent scratches, the applicant also applied lubricant to the outer circumference of the metal jackets of rubber joint 1 5 and rubber joint 2 6 before press-fitting. Applying lubricant further prevents scratches on the outer circumference of the metal jackets of the nodes and the inner circumference of the node mounting holes of the rotating arms.

[0051] Among them, such as Figure 2As shown, lubricant is applied to the metal jacket of each rubber joint from bottom to top, with the applied length K not exceeding one-third of the length of the metal jacket. This is because the applicant has discovered through experiments that while applying lubricant can lubricate and reduce scratches, excessive application can reduce the interference fit force of the node, making the interference fit force less than the axial fatigue load, which can lead to the problem of the node moving up and down during operation. In this embodiment, the lubricant can be made of molybdenum disulfide, etc. By applying an appropriate lubricant, the problem of scratches on the outer circumference of the node metal jacket and the inner circumference of the node mounting hole of the rotating arm can be further solved, while also ensuring that the node has sufficient interference fit force after installation, preventing the problem of the node moving up and down during operation.

[0052] Fourth, to further avoid scratches, the applicant also controlled the press speed, controlling the press to slowly press the node into the node installation hole. The press speed should not be too fast, and the preferred press speed is 50 to 100 mm / min.

[0053] 5. To further avoid scratches, it is also necessary to ensure that the pressure applied is vertical.

[0054] To this end, the applicant designed a set of press fittings, such as Figure 13 and Figure 14As shown, the pressing tool includes a base plate 12, a support tube 13 and a support tube 2 14 arranged on the base plate 12, and a positioning tube 15 is slidably connected inside the support tube 2 14. Inside the support tube 2 14, the bottom of the positioning tube 15 is supported on the base plate 12 by a spring 16. In this embodiment, the spring 16 adopts a compression spring, and a positioning groove 151 is provided on the top of the positioning tube 15 to match one end of the node core shaft 4. The pressing tool also includes a pressing head 17, the top of the pressing head 17 is connected to the press, so that under the action of the press, the pressing head 17 can be driven to move up and down, and a positioning groove 2 171 is provided on the bottom surface of the pressing head 17 to match the other end of the node core shaft 4, and the central axis of the pressing head 17 coincides with the central axis of the positioning tube 15 and the support tube 2 14. When press-fitting, place one end of the swing arm 1 on the top 141 of the cylinder of the supporting cylinder 2 14, so that the positioning cylinder 15 is located inside the node mounting hole 3 on one end of the swing arm 1 and the central axis of the node mounting hole 3 coincides with the central axis of the positioning cylinder 15, and place the other end of the swing arm 1 on the supporting cylinder 1 13. After placement, the swing arm 1 is in a horizontal state; then place the two-section outer sleeve lightweight axle box swing arm node 2 with the snap ring 7 vertically, so that the core shaft 4 of the two-section outer sleeve lightweight axle box swing arm node 2 is One end is located in the positioning groove 151, and then the press is controlled to drive the pressure head 17 downward, so that the other end of the core shaft 4 of the two-section sleeve-type lightweight axle box arm node 2 is inserted into the positioning groove 2 171, and finally the pressure head 17 is controlled to press down, first the rubber joint 2 6 of the two-section sleeve-type lightweight axle box arm node 2 is pressed into the node mounting hole 3, and then after removing the retaining ring 7, the pressure head 17 is continued to be controlled to press down until the rubber joint 1 5 of the two-section sleeve-type lightweight axle box arm node 2 is also pressed into the node mounting hole 3, completing the press-fitting work. This embodiment designs the positioning structure of the positioning groove 1 of the positioning cylinder and the positioning groove 2 of the pressure head in the tooling and makes the central axis of the pressure head coincide with the central axis of the positioning cylinder and the support cylinder 2, thereby ensuring that the press can apply vertical pressure to the end face of the metal sleeve, thereby further avoiding the occurrence of scratches.

[0055] The press-fitting stroke is calculated in advance and is achieved by forming a limiting structure through the pressure head 17 and the support cylinder 14. That is, during the pressing process, when the bottom of the pressure head 17 contacts the top 141 of the cylinder body of the support cylinder 14, it indicates that the press-fitting is completed. At this time, the two-section sleeve-type lightweight axle box arm node 2 has been pressed into place.

[0056] On the outer circumference of the positioning tube 15, there are respectively provided outwardly protruding sliders 152 and 153 at opposite positions, and on the inner circumference of the supporting tube 2 14, there are respectively provided sliding grooves 142 and 143 at opposite positions. By inserting the sliders 152 and 153 of the positioning tube 15 into the sliding grooves 142 and 143 respectively, the positioning tube 15 is slidably connected to the inside of the supporting tube 2 14 by utilizing the mutual cooperation between the sliders and the sliding grooves.

[0057] Support tube 2 (14) is also equipped with removable inserts (18) and (2) (19) located at the top of chute 1 (142) and chute 2 (143). During the downward pressing process, the spring (16) below the positioning tube (15) is compressed, allowing the positioning tube (15) to move downward. When the assembled rotating arm needs to be removed, inserts (18) and (2) are first installed, and then the pressure relief control pressure head (17) is moved upward. Under the restoring force of spring (16), the positioning tube (15) moves upward. During this upward movement, inserts (18) and (2) (19) contact the sliders (152) and (153) of the positioning tube (15), forming a limiting structure. This prevents the positioning tube (15) from popping out of support tube 2 (14), ensuring the normal press-fitting process.

[0058] like Figure 14 As shown, a composite material layer 20, such as nylon, is provided on the outer circumference of the positioning tube 15. When the positioning tube 15 passes through the node mounting hole 3 of the rotating arm, since the texture of the composite material layer 20 is softer than the rotating arm, even if there is a contact scratch, it is the composite material layer 20 of the positioning tube 15 that is scratched, and the inner circumference of the node mounting hole 3 of the rotating arm will not be scratched.

[0059] like Figure 13 As shown, an annular step portion 131 is provided on the top of the support cylinder 13. Figure 1 As shown, a mounting hole 21 is opened at the other end of the rotating arm 1. When the other end of the rotating arm 1 is placed on the supporting cylinder 13, the annular step portion 131 is used to position and support the mounting hole 21.

[0060] In order to facilitate the movement of the press-fitting tool, a ball 22 , such as a bull's eye ball, may be provided on the bottom plate 12 of the tool.

[0061] In summary, the present invention forms an integral structure between rubber joint 1, rubber joint 2 and the snap ring by adding a snap ring in the first half of press-fitting, so that the force on rubber joint 1 and rubber joint 2 is uniform, and the tilting of rubber joint 1 located at the upper position is avoided; before the second half of press-fitting, the snap ring is taken out first, and then the press-fitting work is continued. Through the above press-fitting method, the present invention will not scratch the outer peripheral surface of the metal jacket of the node and the inner peripheral surface of the node mounting hole of the swing arm when press-fitting the two-section jacket-type lightweight axle box swing arm node, meeting the maintenance requirements and ensuring that there is sufficient interference press-fitting force between the mating surfaces, preventing the node from moving up and down during operation, and ultimately ensuring the performance of the bogie. The snap ring is designed to be a split structure and a gap one is reserved between the two split snap rings after installation, so that the snap ring can be easily taken out through the gap one. By rounding the corners, the problem of scratching the outer peripheral surface of the metal jacket of the node and the inner peripheral surface of the node mounting hole of the swing arm can be further avoided. By applying appropriate lubricants, the problem of scratches on the outer circumference of the node's metal jacket and the inner circumference of the node mounting hole of the pivot arm can be further solved, and sufficient interference fit force can be ensured after the node is installed, so that the node will not move up or down during operation. By designing a press-fitting tool, the positioning structure of the positioning groove 1 of the positioning cylinder of the tool and the positioning groove 2 of the pressure head and the positioning structure of the pressure head are aligned with the central axis of the positioning cylinder and the supporting cylinder 2, thereby ensuring that the press can apply vertical pressure to the end face of the metal jacket, thereby further avoiding the occurrence of scratches. By providing a composite material layer on the outer circumference of the positioning cylinder, scratches on the inner circumference of the node mounting hole of the pivot arm are further avoided.

[0062] The term "plurality" in this embodiment refers to "two or more." The above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Persons skilled in the art may make various modifications or alterations without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions are intended to fall within the scope of protection of the present invention, which is defined by the claims.

Claims

1. A method for press-fitting a two-section jacket-type lightweight axle box pivot arm node, which comprises placing the two-section jacket-type lightweight axle box pivot arm node (2) above the node mounting hole (3) of the pivot arm (1), and then vertically pressing the two-section jacket-type lightweight axle box pivot arm node (2) into the node mounting hole (3) of the pivot arm (1), characterized in that: Before press-fitting, a snap ring (7) is first installed at the gap (H) between the rubber joint 1 (5) and the rubber joint 2 (6) of the two-section sleeve-type lightweight axle box arm node (2). During the press-fitting process, the rubber joint 1 (5), the rubber joint 2 (6) and the snap ring (7) are formed into an integral structure by using the action of pressure (F), so that the rubber joint 2 (6) at the lower position is pressed into the node installation hole (3). Then, the press-fitting is stopped, the snap ring (7) is first removed, and then the pressure is continued, and finally the rubber joint 1 (5) at the upper position is also pressed into the node installation hole (3), thereby completing the press-fitting work.

2. The press-fitting method according to claim 1, wherein: The snap ring (7) shown includes an arc-shaped snap ring 1 (71) and an arc-shaped snap ring 2 (72). When the snap ring (7) is inserted into the gap (H) between the rubber joint 1 (5) and the rubber joint 2 (6), a gap 1 (8) is left between the opposite ends of the arc-shaped snap ring 1 (71) and the arc-shaped snap ring 2 (72). When it is necessary to remove the snap ring (7), a tool is inserted into the gap (8) to pry out the arc snap ring (71) and the arc snap ring (72).

3. The press-fitting method according to claim 1, wherein: Before press-fitting, the corners of the metal jackets of the rubber joint 1 (5) and the rubber joint 2 (6) are chamfered, and the corners of the node mounting hole (3) at one end of the swing arm (1) are also chamfered.

4. The press-fitting method according to claim 1, wherein: Before press-fitting, apply lubricant to the outer peripheral surfaces of the metal jackets of rubber joint 1 (5) and rubber joint 2 (6).

5. The press-fitting method according to claim 4, wherein: The lubricant is applied on the metal jacket of each rubber joint from bottom to top, and the applied length (K) does not exceed one third of the length of the metal jacket.

6. The press-fitting method according to claim 1, wherein: The press speed is set at 50 to 100 mm / min.

7. The press-fitting method according to any one of claims 1 to 6, characterized in that: The pressing process is completed on the pressing tooling; The press-fitting tool comprises a base plate (12), a supporting cylinder 1 (13) and a supporting cylinder 2 (14) arranged on the base plate (12), a positioning cylinder (15) is slidably connected inside the supporting cylinder 2 (14), the bottom of the positioning cylinder (15) is supported on the base plate (12) by a spring (16) inside the supporting cylinder 2 (14), a positioning groove 1 (151) matching one end of the core shaft (4) of the node is provided on the top of the positioning cylinder (15), the press-fitting tool also comprises a pressing head (17), the top of the pressing head (17) is connected to the press, a positioning groove 2 (171) matching the other end of the core shaft (4) of the node is provided on the bottom surface of the pressing head (17), and the central axis of the pressing head (17) coincides with the central axis of the positioning cylinder (15) and the central axis of the supporting cylinder 2 (14); When press-fitting, one end of the rotating arm (1) is placed on the top (141) of the cylinder of the second supporting cylinder (14), so that the positioning cylinder (15) is located inside the node mounting hole (3) on one end of the rotating arm (1) and the central axis of the node mounting hole (3) coincides with the central axis of the positioning cylinder (15). The other end of the rotating arm (1) is placed on the supporting cylinder (13). After placement, the rotating arm (1) is in a horizontal state. Then, the two-section outer sleeve type lightweight axle box rotating arm node (2) with the snap ring (7) is vertically mounted. Place it directly on the positioning cylinder (15) so that one end of the node's core shaft (4) is located in the positioning groove (151), and then control the press to drive the pressure head (17) to move downward so that the other end of the node's core shaft (4) is inserted into the positioning groove (171). Finally, control the pressure head (17) to press down, first press the rubber joint (6) into the node installation hole (3), and then remove the retaining ring (7). Continue to control the pressure head (17) to press down until the rubber joint (5) is also pressed into the node installation hole (3), completing the press-fitting work.

8. The press-fitting method according to claim 7, wherein: During the pressing operation, the pressing stroke is controlled by adjusting the distance that the pressing head (17) moves downward when the pressing head (17) starts to press downward until the bottom of the pressing head (17) contacts the top (141) of the cylinder body of the second support cylinder (14).

9. A press-fitting tool, comprising a base plate (12), a first support tube (13) and a second support tube (14) arranged on the base plate (12), a positioning tube (15) being slidably connected inside the second support tube (14), the bottom of the positioning tube (15) being supported on the base plate (12) by a spring (16) inside the second support tube (14), and a first positioning groove (151) matching one end of the core shaft (4) of the node being provided on the top of the positioning tube (15), characterized in that: The press fitting device further comprises a press head (17) and a retaining ring (7), the top of the press head (17) being connected to the press, and a second positioning groove (171) matching the other end of the core shaft (4) of the node being provided on the bottom surface of the press head (17), and the central axis of the press head (17) coincides with the central axis of the positioning cylinder (15) and the central axis of the second support cylinder (14); The snap ring (7) can be detachably snapped into the gap (H) between the rubber joint 1 (5) and the rubber joint 2 (6) of the two-section jacket-type lightweight axle box swing arm node (2) before press-fitting.

10. The press-fitting tool according to claim 9, characterized in that: A composite material layer (18) is provided on the outer peripheral surface of the positioning cylinder (15).

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