Cold extrusion finishing die structure for half axle gear of differential mechanism

Abstract

The utility model discloses a differential half axle gear cold extrusion finishing die structure. The die structure comprises an upper die base plate and a lower die base plate, the upper die sleeve is arranged on the upper die base plate; the finishing upper die is arranged in the upper die sleeve, and the finishing upper die is used for extruding the large end face of the half axle gear; the finishing upper ejector rod is provided with an extrusion end, the finishing upper ejector rod is arranged in the upper die sleeve, the extrusion end penetrates through the finishing upper die, and an extrusion protrusion is arranged at the extrusion end and used for extruding the end face of an inner hole of the half axle gear. The lower die sleeve is correspondingly arranged below the upper die sleeve; the lower die base plate is arranged in the lower die sleeve; the finishing lower die is arranged on the lower die base plate corresponding to the position of the finishing upper die, and a finishing cavity is formed in the finishing lower die; and the finishing lower ejector rod is provided with an ejection end, and the ejection end extends into the finishing cavity from bottom to top.

Description

Technical Field

[0001] This utility model relates to the field of cold extrusion finishing manufacturing technology, specifically to a cold extrusion finishing mold structure for differential half-shaft gears. Background Technology

[0002] In pursuit of superior performance, new energy vehicles require differentials with high-efficiency torque transmission capabilities to ensure optimal performance under various driving conditions. Consequently, the half-shaft gears within the differential bear high loads and frequent torque variations. Warm forging and cold extrusion finishing have become effective methods for plastic forming of these gears, while tooth surface topology is an important indicator for evaluating the precision of half-shaft gears.

[0003] However, the finishing molds used in the cold finishing of traditional half-shaft gears have the following problems: (1) When the traditional finishing mold is used for cold finishing, the end face of the half-shaft gear shank needs to reserve a lot of allowance to meet the extrusion amount of the finishing mold, which will cause material waste; (2) When the traditional finishing mold extrudes the end face of the half-shaft gear shank, it will cause the shank diameter to be upset, which will increase the allowance for subsequent machining and turning; (3) When the traditional finishing mold is used for cold finishing, the finishing upper ejector in its mold needs a lot of extrusion to make the half-shaft gear boss or the small end plane of the tooth fit against the lower mold, which will lead to excessive cold extrusion finishing tonnage and reduce the service life of the mold; (4) When the finishing upper ejector in the traditional finishing mold extrudes the half-shaft gear shank, it will cause the metal of the small end face of the tooth to shrink radially, which will cause the tooth surface topology to deteriorate, resulting in low gear accuracy. It is often necessary to make the topology deviation meet the requirements by repeatedly modifying the tooth surface locally. Utility Model Content

[0004] The purpose of this invention is to address the problems of traditional finishing dies used in the cold finishing of axle gears, and to design a cold extrusion finishing die structure for differential axle gears, thereby solving the aforementioned problems.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0006] This utility model designs a cold extrusion finishing die structure for a differential half-shaft gear. The die structure includes:

[0007] Upper mold base plate;

[0008] The upper mold sleeve is disposed on the upper mold pad plate;

[0009] A finishing upper die is disposed in the upper die sleeve, and the finishing upper die is used to press the large end face of the half shaft gear;

[0010] A finishing upper ejector pin has an extrusion end. The finishing upper ejector pin is disposed in the upper die sleeve and the extrusion end penetrates the finishing upper die. The extrusion end is provided with an extrusion protrusion, which is used to extrude the inner end face of the half shaft gear.

[0011] The lower mold sleeve is correspondingly disposed below the upper mold sleeve;

[0012] A lower mold pad is disposed in the lower mold sleeve;

[0013] A finishing lower mold is disposed on the lower mold pad plate at a position corresponding to the finishing upper mold, and a finishing cavity is provided in the finishing lower mold;

[0014] And a finishing push rod having an ejector end that extends from bottom to top into the finishing cavity.

[0015] Specifically, this utility model discloses a cold extrusion finishing die for a differential half-shaft gear. By improving the design of the finishing upper push rod structure and setting extrusion protrusions on the finishing upper push rod, the extrusion accuracy of the half-shaft gear is improved, while the service life of the die is also improved, the machining allowance is reduced, and good economic benefits are generated.

[0016] Furthermore, a cold extrusion finishing die structure for a differential half-shaft gear includes an upper die inner washer; the upper die inner washer is disposed in the upper die sleeve, the finishing upper die is disposed on the upper die inner washer, and the finishing upper ejector rod is disposed in the upper die inner washer.

[0017] Furthermore, a cold extrusion finishing die structure for a differential half-shaft gear includes a lower die inner pad; the lower die inner pad is disposed between the lower die pad and the finishing lower die.

[0018] Furthermore, a cold extrusion finishing die structure for a differential half-shaft gear includes a lower die insert; the lower die insert is disposed on the lower die pad, and the lower die inner pad and the finishing lower die are disposed in the lower die insert.

[0019] Furthermore, a cold extrusion finishing die structure for a differential half-shaft gear: the finishing lower push rod extends through the lower die pad, the lower die inner pad, and the finishing lower die to the finishing cavity of the finishing lower die.

[0020] Furthermore, a cold extrusion finishing die structure for a differential half-shaft gear: the extrusion protrusion is configured to match the shape of the inner end face of the half-shaft gear.

[0021] The beneficial effects of this utility model are:

[0022] (1) The differential half-shaft gear cold extrusion finishing die structure designed in this utility model improves the design of the finishing upper push rod structure by setting an extrusion protrusion at the extrusion end of the finishing upper push rod that matches the end face of the inner hole of the half-shaft gear. During the finishing process, the large end face and the inner hole end face of the half-shaft gear are respectively subjected to pressure applied by the finishing upper die and the extrusion protrusion in the finishing upper push rod. The extrusion protrusion extrudes the upper end face of the inner hole, which can improve the metal flow efficiency of the forging (half-shaft gear) inner hole, making it easier for the small end boss of the tooth to fit into the finishing lower die, while avoiding the problem of radial shrinkage of the small end metal of the tooth surface, thus ensuring the accuracy of the tooth surface topology mesh. That is, the finishing die structure designed in this utility model solves the problem of large local topology mesh deviation of the tooth surface, greatly improves the gear accuracy, and ensures the stability of product quality.

[0023] (2) The mold structure designed in this utility model improves the finishing upper ejector by setting an extrusion protrusion at the extrusion end of the finishing upper ejector. The extrusion protrusion extrudes the upper end face of the inner hole of the half-shaft gear, thereby allowing the end face of the gear shank to be subjected to a small amount of extrusion or no extrusion. Therefore, the gear shank does not need to reserve a large extrusion allowance, which not only avoids material waste and improves the material utilization rate of the product, but also avoids upsetting the diameter of the shank, reduces the machining cutting allowance, improves the processing efficiency, and reduces the cost of machining cutting tools. At the same time, since the end face of the gear shank is subjected to less extrusion, the cold extrusion finishing tonnage of the half-shaft gear is reduced, the amount of metal extrusion deformation is reduced, thereby improving the service life of the mold structure (finishing lower mold).

[0024] (3) The finishing mold structure designed in this utility model is simple in structure. Compared with the traditional mold used for finishing the differential half shaft gear, the mold structure of this utility model has a very low improvement cost and can effectively control the quality of the product and the upper end face of the inner hole of the half shaft gear forging. It effectively reduces the finishing tonnage. The finishing mold structure of this utility model improves the extrusion accuracy of the half shaft gear, improves the service life of the mold, reduces the machining allowance, and generates good economic benefits. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the half-shaft gear in Example 1;

[0027] Figure 2A schematic diagram of a cold extrusion finishing die structure for a differential half-shaft gear designed for Embodiment 1 of this utility model;

[0028] Figure 3 This is a schematic diagram illustrating the operation of finishing a half-shaft gear using the finishing mold of Example 1.

[0029] Figure 4 A schematic diagram of the structure of a conventional cold extrusion finishing die provided for Comparative Example 1;

[0030] Figure 5 This is a schematic diagram illustrating the operation of finishing a half-shaft gear using the finishing mold of Comparative Example 1.

[0031] The markings in the diagram are: 1-Upper mold pad, 2-Upper mold sleeve, 3-Finishing upper mold, 4-Finishing upper ejector pin, 5-Lower mold sleeve, 6-Lower mold pad, 7-Finishing lower mold, 8-Finishing lower ejector pin, 9-Upper mold inner washer, 10-Lower mold inner pad, 11-Lower mold insert, 41-Extrusion end, 42-Extrusion protrusion, 71-Finishing cavity, 81-Ejection end, 12-Half shaft gear, 121-Large end face, 122-Inner hole end face, 123-Handle end face, 124-Small tooth end face. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0033] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," "right," "top," and "bottom," etc., indicating orientation or positional relationships, are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein.

[0034] Example 1

[0035] like Figures 1-2 As shown in the figure, this embodiment 1 designs a cold extrusion finishing die structure for differential half-shaft gears. The die structure includes the following:

[0036] Upper mold pad 1;

[0037] Upper mold sleeve 2 is disposed on the upper mold pad 1;

[0038] The upper mold inner washer 9 is disposed in the upper mold sleeve 2;

[0039] The finishing upper die 3 is disposed in the upper die sleeve 2 and on the upper die inner washer 9. The finishing upper die 3 is used to press the large end face 121 of the half shaft gear 12.

[0040] The finishing upper ejector rod 4 has an extrusion end 41. The finishing upper ejector rod 4 is disposed in the inner washer 9 of the upper mold and the extrusion end 41 penetrates the finishing upper mold 3. The extrusion end 41 is provided with an extrusion protrusion 42 that matches the shape of the inner hole end face 122 of the half shaft gear 12. The extrusion protrusion 42 is used to extrude the inner hole end face 122 of the half shaft gear 12.

[0041] The lower mold sleeve 5 is correspondingly disposed below the upper mold sleeve 2;

[0042] The lower mold pad 6 is disposed in the lower mold sleeve 5;

[0043] The lower mold insert 11 is disposed in the lower mold sleeve 5 and on the lower mold pad 6;

[0044] The lower mold inner pad 10 is disposed in the lower mold insert 11 and on the lower mold pad 6;

[0045] The finishing lower mold 7 is positioned on the inner pad plate 10 of the lower mold, corresponding to the position of the finishing upper mold 3, and the finishing lower mold 7 is provided with a finishing cavity 71.

[0046] And finishing lower ejector pin 8, which has an ejector end 81, which extends from bottom to top through the lower mold pad 6, the lower mold inner pad 10 and the finishing lower mold 7 into the finishing cavity 71.

[0047] Cold extrusion finishing process: such as Figure 3 As shown, the half-shaft gear 12 is placed in the finishing cavity 71 of the finishing lower die 7. The finishing upper die 3 and the finishing upper ejector rod 4 move downward under the action of the press to extrude the half-shaft gear 12. During this process, the large end face 121 and the inner end face 122 of the half-shaft gear 12 are respectively subjected to the pressure of the extrusion protrusions 42 in the finishing upper die 3 and the finishing upper ejector rod 4. The extrusion protrusions 42 extrude the inner end face 122, thereby improving the metal flow efficiency of the forging's inner hole, making the small end face 124 of the gear more easily fit the finishing lower die 7, and avoiding the problem of radial shrinkage of the metal on the small end face of the gear, thus ensuring the accuracy of the topology mesh. When demolding after finishing, the finishing lower ejector rod 8 pushes the half-shaft gear 12 out.

[0048] Comparative Example 1

[0049] A traditional finishing mold structure is provided, such as Figure 4 As shown, the difference between the finishing mold of Comparative Example 1 and the mold of Example 1 is that the ejector end 41 of the finishing upper ejector rod 4 of the finishing mold of Comparative Example 1 does not have a pressing protrusion 42 structure that matches the shape of the inner hole end face 122 of the half shaft gear 12. Therefore, as Figure 5As shown, when using the finishing mold of Comparative Example 1 for cold extrusion finishing, the following problems will be encountered: (1) Since the finishing upper ejector rod 4 in the mold of Comparative Example 1 is not provided with extrusion protrusion 42, it mainly extrudes the shank end face 123 of the half shaft gear 12 by the finishing upper ejector rod 4 to achieve the fit between the small end face 124 of the gear and the finishing lower mold 7, thereby achieving finishing. In this process, the extrusion amount of the finishing upper ejector rod 4 on the shank end face 123 is large, so the shank end face 123 needs to reserve a large amount of allowance to meet the extrusion amount of the finishing mold, which will cause material waste; (2) Based on the finishing mold structure of Comparative Example 1, the extrusion amount of the finishing upper ejector rod 4 on the shank end face 123 is large. (3) Because the amount of extrusion of the finishing upper ejector 4 on the end face 123 of the shank is large, the cold extrusion finishing tonnage is too large, which will reduce the service life of the mold. (4) Because the finishing upper ejector 4 of Comparative Example 1 is not equipped with extrusion protrusion 42, the finishing upper ejector 4 of Comparative Example 1 can only extrude the end face 123 of the shank and cannot extrude the end face 122 of the inner hole. The complete extrusion of the end face 123 of the shank will cause the metal of the small end face 124 of the tooth to shrink radially, resulting in the problem of the tooth surface topology mesh deterioration, which will result in the gear accuracy being low. It is necessary to make the topology deviation meet the requirements by multiple local tooth surface modifications.

[0050] This invention improves the flow efficiency of metal in the inner hole of the half-shaft gear 12 by setting extrusion protrusions 42 on the extrusion end 41 of the finishing upper push rod 4, and using the extrusion protrusions 42 to extrude the inner hole end face 122, so as to make the small tooth end 124 more easily fit the finishing lower die 7, avoid the problem of radial shrinkage of the metal at the small tooth end, ensure the accuracy of the tooth surface topology grid, and thus improve the accuracy of gear finishing.

[0051] The above-described preferred embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of this utility model. Any obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. A cold extrusion finishing die structure for a differential half-shaft gear, characterized in that, The mold structure includes: Upper mold pad (1); Upper mold sleeve (2) is disposed on the upper mold pad (1); A finishing upper die (3) is disposed in the upper die sleeve (2), and the finishing upper die (3) is used to press the large end face (121) of the half shaft gear (12); A finishing upper ejector rod (4) has an extrusion end (41) thereon. The finishing upper ejector rod (4) is disposed in the upper mold sleeve (2) and the extrusion end (41) penetrates the finishing upper mold (3). The extrusion end (41) is provided with an extrusion protrusion (42) for extruding the inner end face (122) of the half shaft gear (12). The lower mold sleeve (5) is correspondingly disposed below the upper mold sleeve (2); The lower mold pad (6) is disposed in the lower mold sleeve (5); The finishing lower mold (7) is positioned on the lower mold pad (6) corresponding to the finishing upper mold (3), and the finishing lower mold (7) is provided with a finishing cavity (71); And a finishing push rod (8) having an ejector end (81) extending from bottom to top into the finishing cavity (71).

2. The differential half-shaft gear cold extrusion finishing die structure according to claim 1, characterized in that, The mold structure also includes an inner gasket (9) for the upper mold; The upper mold inner washer (9) is disposed in the upper mold sleeve (2), the finishing upper mold (3) is disposed on the upper mold inner washer (9), and the finishing upper ejector rod (4) is disposed in the upper mold inner washer (9).

3. The differential half-shaft gear cold extrusion finishing die structure according to claim 1, characterized in that, The mold structure also includes a lower mold inner pad (10); The lower mold inner pad (10) is disposed between the lower mold pad (6) and the finishing lower mold (7).

4. The differential half-shaft gear cold extrusion finishing die structure according to claim 3, characterized in that, The mold structure also includes a lower mold insert (11); The lower mold insert (11) is disposed on the lower mold pad (6), and the lower mold inner pad (10) and the finishing lower mold (7) are disposed in the lower mold insert (11).

5. The differential half-shaft gear cold extrusion finishing die structure according to claim 4, characterized in that, The finishing ejector pin (8) extends through the lower mold pad (6), the lower mold inner pad (10) and the finishing lower mold (7) into the finishing cavity (71).

6. The differential half-shaft gear cold extrusion finishing die structure according to claim 1, characterized in that, The extrusion protrusion (42) is configured to be adapted to the shape of the inner end face (122) of the half-shaft gear (12).

Images