Cold pressing die for ball spline outer shaft

Abstract

The cold pressing die comprises an upper die part and a lower die part capable of being in press fit with the upper die part, a forward extrusion head, a reducing head and a spline head are fixedly connected to the end face of the side, close to the lower die part, of the upper die part, and a forward extrusion cavity, a reducing cavity and a spline cavity are formed in the end face of the side, close to the upper die part, of the lower die part; according to the cold pressing die for the ball spline outer shaft, a three-station composite continuous cold forging forming process is adopted, a pipe material forward extrusion station, a diameter reducing station and a spline extrusion station are arranged, extrusion forming actions of the three stations can be synchronously executed in one-time die assembly, the forming efficiency of a workpiece is greatly improved, and the production cost is reduced. And meanwhile, the pipe forward extrusion procedure is added in the workpiece machining process, the deformation amount of single-time machining can be reduced, the working stability of the die and the error control precision of the workpiece are improved, and the overall quality of the workpiece is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of component processing, and particularly relates to a cold pressing die for a ball spline outer shaft. Background Art

[0002] With the development of domestic automotive technology, the structural requirements for key automotive transmission components are also getting higher and higher. The ball spline outer shaft mainly consists of two major features: an internal spline and a rod portion. Among them, the cold-forged ball spline outer shaft can achieve high precision, good comprehensive mechanical properties, and better meet the needs of the automotive industry.

[0003] During the cold forging process of the ball spline outer shaft, there are problems such as the spline part of the ball spline outer shaft being too long and the rod portion being too thin with a large deformation ratio, resulting in difficulties in cold forging forming. Most traditional cold forging dies for ball spline outer shafts use a single cavity design, which cannot meet the rapid forming of ball spline outer shafts and affects the production rhythm. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a cold pressing die for a ball spline outer shaft with strong working reliability and high production efficiency.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions.

[0006] The present application provides a cold pressing die for a ball spline outer shaft, including an upper die member and a lower die member that can be pressed together with the upper die member;

[0007] A forward extruding head, a diameter reducing head, and a spline head are fixedly connected to the end face of the upper die member close to the lower die member, and a forward extruding cavity, a diameter reducing cavity, and a spline cavity are provided on the end face of the lower die member close to the upper die member;

[0008] Among them, the forward extruding cavity is used to install a tubular workpiece, and the forward extruding head can be inserted into the forward extruding cavity to extrude the tubular workpiece in the forward extruding cavity into a forward extruded part;

[0009] The diameter reducing cavity is used to install the forward extruded part, and the diameter reducing head can be inserted into the diameter reducing cavity to extrude the forward extruded part in the diameter reducing cavity into a diameter reduced part;

[0010] The spline cavity is used to install the diameter reduced part, and the spline head can be inserted into the spline cavity to extrude the diameter reduced part in the spline cavity into a formed part.

[0011] Further defined, in the above-mentioned cold pressing die for a ball spline outer shaft, the forward extruding head, the diameter reducing head, and the spline head are respectively fixedly connected to the upper die member through positioning tooling;

[0012] And / or, the forward extruding cavity, the diameter reducing cavity, and the spline cavity are respectively arranged on the lower die member through die core assemblies.

[0013] Further defined, for a cold pressing die for the outer shaft of a ball spline as described above, wherein the upper die member includes an upper die frame, and the positioning tooling includes an outer sleeve fixedly arranged on the upper die frame, a positioning module embedded in the outer sleeve, and a locking member fixedly connected to the end of the outer sleeve away from the upper die frame;

[0014] Wherein, the forward extrusion head, the diameter reducing head, and the spline head respectively penetrate through the locking members at corresponding positions, and the locking members can limit the displacement of the forward extrusion head, the diameter reducing head, and the spline head towards the side close to the lower die member;

[0015] Both ends of the positioning module are respectively in contact with the upper die frame and the locking member, and the positioning module can contact the forward extrusion head, the diameter reducing head, and the spline head to limit the displacement of the forward extrusion head, the diameter reducing head, and the spline head towards the side away from the lower die member.

[0016] Further defined, for a cold pressing die for the outer shaft of a ball spline as described above, wherein the end of the outer sleeve away from the lower die member is fixedly connected to the upper die frame by bolts, and the end close to the lower die member is fixedly connected to the locking member by bolts.

[0017] Further defined, for a cold pressing die for the outer shaft of a ball spline as described above, wherein the positioning module includes a base, a transition member, and a positioning member;

[0018] Wherein, the end of the base away from the lower die member is in contact with the upper die frame, the end close to the lower die member is in contact with the transition member, the transition member is in interference fit with the outer sleeve, and the end close to the lower die member is in contact with the positioning member, and the end of the positioning member away from the transition member is in contact with the locking member.

[0019] Further defined, for a cold pressing die for the outer shaft of a ball spline as described above, wherein a locking sleeve is in interference fit inside the locking member, the locking member can limit the displacement of the locking sleeve towards the side close to the lower die member, and the end of the locking sleeve away from the lower die member is in contact with the positioning module;

[0020] Wherein, the forward extrusion head, the diameter reducing head, and the spline head penetrate through the locking sleeves at corresponding positions and are in interference fit with the locking sleeves at corresponding positions, and the locking sleeves can limit the displacement of the forward extrusion head, the diameter reducing head, and the spline head towards the side close to the lower die member.

[0021] Further defined, for a cold pressing die for the outer shaft of a ball spline as described above, which further includes a knockout assembly for separating the spline head from the formed part.

[0022] Further defined, for a cold pressing die for the outer shaft of a ball spline as described above, wherein the knockout assembly includes a sliding cavity arranged in the transition member at the corresponding position of the spline head, a sliding plate is slidably connected along the axial direction of the spline head in the sliding cavity, a guide rod is fixedly arranged at the end of the sliding plate close to the lower die member, and a knockout push rod is fixedly arranged at the end of the sliding plate away from the lower die member;

[0023] One end of the guide rod away from the slide plate extends to the side of the locking member close to the lower die member and is fixedly connected with a knockout head, and one end of the knockout push rod away from the slide plate extends to the side of the upper die member away from the lower die member;

[0024] Wherein, the spline head penetrates through the knockout head, and one end of the knockout head close to the lower die member can abut against one end of the corresponding forming member close to the upper die member.

[0025] Further defined, in the above-mentioned cold forging die for the outer shaft of the ball spline, further includes a demolding ejector rod arranged on the lower die member and used for ejecting the workpieces in the forward extrusion cavity, diameter reduction cavity and spline cavity.

[0026] Further defined, in the above-mentioned cold forging die for the outer shaft of the ball spline, further includes a driving unit for driving the relative movement of the upper die member and the lower die member.

[0027] The present invention has at least the following beneficial effects:

[0028] 1. Adopt a three-station composite continuous cold forging forming process, and respectively set a tube blank forward extrusion, diameter reduction and spline extrusion stations. The extrusion forming actions of the three stations can be synchronously executed in one mold closing, greatly improving the forming efficiency of the workpiece. At the same time, adding a tube blank forward extrusion process during the workpiece processing can reduce the deformation amount of a single processing, improve the working stability of the die and the error control accuracy of the workpiece, and further improve the overall quality of the workpiece;

[0029] 2. Through the modular installation of the forward extrusion head, diameter reduction head and spline head on the upper die member, and the modular setting form of the forward extrusion cavity, diameter reduction cavity and spline cavity on the lower die member, it is not only convenient for the loading, unloading and maintenance of components, but also can quickly replace the appropriate fittings for workpieces of different specifications, improving the overall practicality of the die;

[0030] 3. Through the lock sleeve, on the one hand, it can realize the installation and positioning of the forward extrusion head, diameter reduction head and spline head. On the other hand, through the interference fit between the lock sleeve and the locking member, and the interference fit between the lock sleeve and the forward extrusion head, diameter reduction head and spline head, the axial position accuracy of the forward extrusion head, diameter reduction head and spline head can be guaranteed, so as to ensure the fitting accuracy between the forward extrusion head, diameter reduction head, spline head and the forward extrusion cavity, diameter reduction cavity and spline cavity, and further improve the workpiece processing quality;

[0031] 4. After the upper die and the lower die are closed and the forming of the formed part in the spline cavity is completed, the upper die and the lower die reset. The spline head drives the formed part in the spline cavity to move towards the side close to the upper die. At this time, the knockout head and the spline head move relative to each other until the knockout head abuts against the formed part at the corresponding position. Under the abutment of the knockout head, the displacement of the formed part relative to the lower die is restricted, that is, the formed part and the spline head move relative to each other, and the spline head disengages from the through hole of the formed part, thereby realizing the auxiliary separation of the spline head and the formed part, and solving the problem that the punch is wrapped by the outer shaft of the ball spline during the extrusion process. Description of the Drawings

[0032] Figure 1 Structural schematic diagram of the cold pressing die for the outer shaft of the ball spline in the embodiment of the present application;

[0033] Figure 2 Structural schematic diagram of the cold pressing die for the outer shaft of the ball spline in the embodiment of the present application;

[0034] Figure 3 Structural schematic diagram of the "knockout assembly" part in the cold pressing die for the outer shaft of the ball spline in the embodiment of the present application;

[0035] Figure 4 Structural schematic diagram of the "tube blank part 510";

[0036] Figure 5 Structural schematic diagram of the "forward extrusion part 520";

[0037] Figure 6 Structural schematic diagram of the "diameter reducing part 530";

[0038] Figure 7 Structural schematic diagram of the "formed part 540".

[0039] Reference Signs

[0040] Upper die - 100, base - 110, transition part - 120, positioning part - 130, locking part - 140, locking sleeve - 141, sliding cavity - 160, sliding plate - 161, guide rod - 162, knockout push rod - 163, knockout head - 164, outer sleeve - 170, lower die - 200, demolding ejector rod - 210, forward extrusion head - 310, diameter reducing head - 320, spline head - 330, forward extrusion cavity - 410, diameter reducing cavity - 420, spline cavity - 430, tube blank part - 510, forward extrusion part - 520, diameter reducing part - 530, formed part - 540. Detailed Description of the Invention

[0041] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0042] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same type, and do not limit the number of objects. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0043] Next, in conjunction with the accompanying drawings, the cold pressing die for the outer shaft of the ball spline provided by the embodiments of the present application will be described in detail through specific embodiments and their application scenarios.

[0044] As Figures 1 to 7 shown, the embodiments of the present application provide a cold pressing die for the outer shaft of a ball spline, including an upper die member 100 and a lower die member 200 that can be pressed together with the upper die member 100.

[0045] On the end face of the upper die member 100 close to the lower die member 200, a forward extrusion head 310, a diameter-reducing head 320, and a spline head 330 are fixedly connected. On the end face of the lower die member 200 close to the upper die member 100, a forward extrusion cavity 410, a diameter-reducing cavity 420, and a spline cavity 430 are provided.

[0046] Among them, the forward extrusion cavity 410 is used to install a tubular workpiece 510, and the forward extrusion head 310 can be inserted into the forward extrusion cavity 410 to extrude the tubular workpiece 510 in the forward extrusion cavity 410 into a forward extrusion part 520. The diameter-reducing cavity 420 is used to install the forward extrusion part 520, and the diameter-reducing head 320 can be inserted into the diameter-reducing cavity 420 to extrude the forward extrusion part 520 in the diameter-reducing cavity 420 into a diameter-reduced part 530. The spline cavity 430 is used to install the diameter-reduced part 530, and the spline head 330 can be inserted into the spline cavity 430 to extrude the diameter-reduced part 530 in the spline cavity 430 into a formed part 540.

[0047] It can be understood that, as Figure 4As shown, the tubular workpiece 510 is in a hollow cylindrical shape. After installing the tubular workpiece 510 in the forward extrusion cavity 410, when the upper die 100 and the lower die 200 are closed, the forward extrusion head 310 on the upper die 100 extends into the forward extrusion cavity 410, and the forward extrusion head 310 pushes the tubular workpiece 510 to closely fit with the inner wall of the forward extrusion cavity 410, so that the shape of the tubular workpiece 510 matches the shape of the forward extrusion cavity 410, and then the tubular workpiece 510 is extruded into a forward extrusion part 520; As Figure 5 shown, the diameter of one end of the forward extrusion part 520 away from the upper die 100 decreases, and there is a tapered transition between the part with the unchanged diameter and the part with the decreased diameter. After installing the forward extrusion part 520 in the diameter reduction cavity 420, when the upper die 100 and the lower die 200 are closed, the diameter reduction head 320 on the upper die 100 extends into the diameter reduction cavity 420, and the diameter reduction head 320 pushes the forward extrusion part 520 to closely fit with the inner wall of the diameter reduction cavity 420, so that the shape of the forward extrusion part 520 matches the shape of the diameter reduction cavity 420, and then the forward extrusion part 520 is extruded into a diameter reduction part 530; As Figure 6 、 Figure 7 shown, the diameter reduction part 530 is specifically the forward extrusion part 520 with the diameter of one end away from the upper die 100 further reduced, and the formed part 540 is specifically a spline part formed in the through hole at one end of the diameter reduction part 530 away from the lower die 200. After installing the diameter reduction part 530 in the spline cavity 430, when the upper die 100 and the lower die 200 are closed, the spline head 330 on the upper die 100 extends into the through hole of the diameter reduction part 530, and the spline head 330 extrudes the inner wall of the through hole of the diameter reduction part 530, so that a spline part is formed on the inner wall of the through hole of the diameter reduction part 530, and then the diameter reduction part 530 is extruded into a formed part 540.

[0048] It should be noted that the reason for first extruding the tubular workpiece 510 into the forward extrusion part 520 and then extruding the forward extrusion part 520 into the diameter reduction part 530 is that on the one hand, it is to reduce the deformation amount of a single processing, thereby reducing the required extrusion force during a single processing, and on the other hand, it is convenient for precision control, that is, the extrusion of the tubular workpiece 510 into the forward extrusion part 520 is rough machining or pre - machining, and the extrusion of the forward extrusion part 520 into the diameter reduction part 530 is finish machining, ensuring the forming accuracy of the workpiece.

[0049] In the embodiment of the present application, the above - mentioned cold - pressing die for a ball - spline outer shaft is adopted, and a three - station composite continuous cold - forging forming process is used. The forward extrusion station, diameter reduction station, and spline extrusion station for the tubular workpiece are respectively set. The extrusion forming actions of the three stations can be synchronously executed in one die closing, greatly improving the forming efficiency of the workpiece. At the same time, by adding a forward extrusion process for the tubular workpiece during the workpiece processing, the deformation amount of a single processing can be reduced, the working stability of the die and the error control accuracy of the workpiece can be improved, and the overall quality of the workpiece can be further improved.

[0050] In a preferred embodiment, as Figures 1 to 3 shown, the forward extrusion head 310, the reducing head 320, and the spline head 330 are respectively fixedly connected to the upper die member 100 through a positioning tooling;

[0051] and / or, the forward extrusion cavity 410, the reducing cavity 420, and the spline cavity 430 are respectively arranged on the lower die member 200 through a die core assembly.

[0052] It can be understood that through the modular installation of the forward extrusion head 310, the reducing head 320, and the spline head 330 on the upper die member 100, and the modular setting form of the forward extrusion cavity 410, the reducing cavity 420, and the spline cavity 430 on the lower die member 200, it is not only convenient for the loading, unloading, and maintenance of components, but also can quickly replace the adapters for workpieces of different specifications, improving the overall practicability of the die.

[0053] In a preferred embodiment, as Figures 1 to 3 shown, the upper die member 100 includes an upper die frame. The positioning tooling includes an outer sleeve 170 fixedly arranged on the upper die frame, a positioning module embedded in the outer sleeve 170, and a locking member 140 fixedly connected to one end of the outer sleeve 170 away from the upper die frame.

[0054] Among them, the forward extrusion head 310, the reducing head 320, and the spline head 330 are arranged through the locking member 140, and the locking member 140 can limit the displacement of the forward extrusion head 310, the reducing head 320, and the spline head 330 toward the side close to the lower die member 200;

[0055] Both ends of the positioning module are respectively abutted against the upper die frame and the locking member 140, and the positioning module can abut against the forward extrusion head 310, the reducing head 320, and the spline head 330 to limit the displacement of the forward extrusion head 310, the reducing head 320, and the spline head 330 toward the side away from the lower die member 200.

[0056] It can be understood that through the limiting of the positioning module by the upper die frame and the locking member 140, the forward extrusion head 310, the reducing head 320, and the spline head 330 can be fixed in position relative to the upper die frame, and at the same time, pressure support can be provided when the upper die member 100 and the lower die member 200 are closed.

[0057] In a preferred embodiment, as Figures 1 to 3 shown, one end of the outer sleeve 170 away from the lower die member 200 is fixedly connected to the upper die frame through a bolt, and one end close to the lower die member 200 is fixedly connected to the locking member 140 through a bolt.

[0058] It can be understood that since the outer sleeve 170 is detachably connected to both the upper die frame and the locking member 140, it is convenient for loading, unloading, and replacing the pressure head.

[0059] In a preferred embodiment, as Figures 1 to 3 shown, the positioning module includes a base 110, a transition member 120, and a positioning member 130.

[0060] Among them, one end of the base 110 away from the lower die member 200 abuts against the upper die frame, and one end close to the lower die member 200 abuts against the transition member 120;

[0061] The transition member 120 is in interference fit with the outer sleeve 170, and one end close to the lower die member 200 abuts against the positioning member 130;

[0062] One end of the positioning member 130 away from the transition member 120 abuts against the locking member 140.

[0063] It can be understood that the setting form of the positioning module is not limited to the above one. For example, the positioning member 130 can also be set to be integrally formed with the transition member 120, or the positioning member 130 can be further set to be embedded in the locking member 140 and in interference fit with the locking member 140, as long as the press-fitting of the positioning module in the outer sleeve 170 can be realized, which will not be elaborated here.

[0064] In a preferred embodiment, as Figures 1 to 3 shown, a lock sleeve 141 is in interference fit inside the locking member 140. The locking member 140 can limit the displacement of the lock sleeve 141 towards the side close to the lower die member 200, and one end of the lock sleeve 141 away from the lower die member 200 abuts against the positioning module.

[0065] Among them, the forward extruding head 310, the reducing head 320, and the spline head 330 penetrate through the lock sleeve 141 and are in interference fit with the lock sleeve 141, and the lock sleeve 141 can limit the displacement of the forward extruding head 310, the reducing head 320, and the spline head 330 towards the side close to the lower die member 200.

[0066] It can be understood that on the one hand, the lock sleeve 141 can realize the installation and positioning of the forward extruding head 310, the reducing head 320, and the spline head 330. On the other hand, through the interference fit between the lock sleeve 141 and the locking member 140, and the interference fit between the lock sleeve 141 and the forward extruding head 310, the reducing head 320, and the spline head 330, the axial position accuracy of the forward extruding head 310, the reducing head 320, and the spline head 330 can be ensured, so as to ensure the fitting accuracy between the forward extruding head 310, the reducing head 320, the spline head 330 and the forward extruding cavity 410, the reducing cavity 420, and the spline cavity 430, and further improve the workpiece processing quality.

[0067] In a preferred embodiment, as Figures 1 to 3 shown, it further includes a demolding ejector rod 210 provided on the lower die member 200 and used for ejecting the workpiece in the forward extruding cavity 410, the reducing cavity 420, and the spline cavity 430.

[0068] In a preferred embodiment, as Figures 1 to 3 shown, there are three ejection pins 210 slidably arranged on the lower die member 200, and the three ejection pins 210 respectively correspond to the positions of the forward extrusion cavity 410, the diameter-reducing cavity 420, and the spline cavity 430.

[0069] Among them, one end of the ejection pin 210 close to the upper die member 100 can extend into the forward extrusion cavity 410, the diameter-reducing cavity 420, and the spline cavity 430 to eject the workpiece at the corresponding position.

[0070] In a preferred embodiment, as Figures 1 to 3 shown, there is also a knockout assembly for separating the spline head 330 from the formed part 540.

[0071] It can be understood that since the spline head 330 extrudes the spline by extending into the through hole of the diameter-reducing part 530, when the diameter-reducing part 530 in the spline cavity 430 is extruded into the formed part 540, the spline head 330 will be extruded against the inner wall of the through hole of the formed part 540, making it difficult to separate the spline head 330 from the formed part 540. Therefore, a knockout assembly needs to be provided to assist in separating the spline head 330 from the formed part 540.

[0072] In a preferred embodiment, as Figures 1 to 3 shown, the knockout assembly includes a sliding cavity 160 provided in the transition member 120 at the corresponding position of the spline head 330. A sliding plate 161 is slidably connected along the axial direction of the spline head 330 in the sliding cavity 160. One end of the sliding plate 161 close to the lower die member 200 is fixedly provided with a guide rod 162, and the end far from the lower die member 200 is fixedly provided with a knockout push rod 163.

[0073] One end of the guide rod 162 far from the sliding plate 161 extends to the side of the locking member 140 close to the lower die member 200 and is fixedly connected with a knockout head 164. One end of the knockout push rod 163 far from the sliding plate 161 extends to the side of the upper die member 100 far from the lower die member 200.

[0074] Among them, the spline head 330 penetrates through the knockout head 164, and one end of the knockout head 164 close to the lower die member 200 can abut against one end of the corresponding formed part 540 close to the upper die member 100.

[0075] It can be understood that after the upper mold part 100 and the lower mold part 200 are closed and the forming of the formed part 540 in the spline cavity 430 is completed, the upper mold part 100 and the lower mold part 200 reset. The spline head 330 drives the formed part 540 in the spline cavity 430 to move towards the side close to the upper mold part 100. At this time, the knockout head 164 and the spline head 330 move relatively until the knockout head 164 abuts against the formed part 540 at the corresponding position. Under the abutment of the knockout head 164, the displacement of the formed part 540 relative to the lower mold part 200 is restricted, that is, the formed part 540 and the spline head 330 move relatively, and the spline head 330 disengages from the through hole of the formed part 540, thereby realizing the auxiliary separation of the spline head 330 and the formed part 540, and solving the problem that the outer shaft of the ball spline wraps the punch during the extrusion process.

[0076] In a preferred embodiment, it further includes a driving unit for driving the relative movement of the upper mold part 100 and the lower mold part 200.

[0077] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0078] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection scope of the present application.

Claims

1. A cold pressing die for a ball spline outer shaft, characterized in that It includes an upper die module and a lower die module that can be pressed together with the upper die module; On the end face of the upper die module close to the lower die module, a forward extrusion head, a reducing head, and a spline head are fixedly connected. On the end face of the lower die module close to the upper die module, a forward extrusion cavity, a reducing cavity, and a spline cavity are provided; Among them, the forward extrusion cavity is used to install a tubular workpiece, and the forward extrusion head can be inserted into the forward extrusion cavity to extrude the tubular workpiece in the forward extrusion cavity into a forward extrusion part; The reducing cavity is used to install the forward extrusion part, and the reducing head can be inserted into the reducing cavity to extrude the forward extrusion part in the reducing cavity into a reducing part; The spline cavity is used to install the reducing part, and the spline head can be inserted into the spline cavity to extrude the reducing part in the spline cavity into a formed part.

2. The cold pressing die for the outer shaft of the ball spline according to claim 1, characterized in that, The forward extrusion head, the reducing head, and the spline head are respectively fixedly connected to the upper die module through a positioning tooling; And / or, the forward extrusion cavity, the reducing cavity, and the spline cavity are respectively arranged on the lower die module through a die core assembly.

3. A cold pressing die for the outer shaft of a ball spline according to claim 2, characterized in that, The upper die module includes an upper die frame. The positioning tooling includes an outer sleeve fixedly arranged on the upper die frame, a positioning module embedded in the outer sleeve, and a locking part fixedly connected to the end of the outer sleeve away from the upper die frame; Among them, the forward extrusion head, the reducing head, and the spline head respectively penetrate through the locking parts at corresponding positions, and the locking part can limit the displacement of the forward extrusion head, the reducing head, and the spline head toward the side close to the lower die module; Both ends of the positioning module are respectively abutted against the upper die frame and the locking part, and the positioning module can abut against the forward extrusion head, the reducing head, and the spline head to limit the displacement of the forward extrusion head, the reducing head, and the spline head toward the side away from the lower die module.

4. A cold pressing die for the outer shaft of a ball spline according to claim 3, characterized in that, The end of the outer sleeve away from the lower die module is bolted to the upper die frame, and the end close to the lower die module is bolted to the locking part.

5. A cold pressing die for the outer shaft of a ball spline according to claim 3 or 4, characterized in that, The positioning module includes a base, a transition part, and a positioning part; Among them, the end of the base away from the lower die module is abutted against the upper die frame, the end close to the lower die module is abutted against the transition part, the transition part is in interference fit with the outer sleeve, and the end close to the lower die module is abutted against the positioning part. The end of the positioning part away from the transition part is abutted against the locking part.

6. A cold pressing die for the outer shaft of a ball spline according to claim 5, characterized in that, A locking sleeve is in interference fit inside the locking part. The locking part can limit the displacement of the locking sleeve toward the side close to the lower die module, and the end of the locking sleeve away from the lower die module is abutted against the positioning module; Among them, the forward extrusion head, the reducing head, and the spline head penetrate through the locking sleeves at corresponding positions and are in interference fit with the locking sleeves at corresponding positions. The locking sleeve can limit the displacement of the forward extrusion head, the reducing head, and the spline head toward the side close to the lower die module.

7. A cold pressing die for the outer shaft of a ball spline according to claim 5, characterized in that It further includes a knockout component for separating the spline head from the formed part.

8. A cold pressing die for the outer shaft of a ball spline according to claim 7, characterized in that, The knockout component includes a sliding cavity arranged in the transition part at the corresponding position of the spline head. A sliding plate is slidably connected in the sliding cavity along the axial direction of the spline head. A guide rod is fixedly arranged at the end of the sliding plate close to the lower die module, and a knockout push rod is fixedly arranged at the end of the sliding plate away from the lower die module; The end of the guide rod away from the sliding plate extends to the side of the locking part close to the lower die module and is fixedly connected with a knockout head. The end of the knockout push rod away from the sliding plate extends to the side of the upper die module away from the lower die module; Among them, the spline head penetrates through the knockout head, and the end of the knockout head close to the lower die module can be abutted against the end of the corresponding formed part close to the upper die module.

9. A cold pressing die for the outer shaft of a ball spline according to claim 1, characterized in that It further includes a demoulding ejector rod disposed on the lower die member and used for ejecting the workpieces in the direct extrusion cavity, the reducing cavity, and the spline cavity.

10. A cold pressing die for the outer shaft of a ball spline according to claim 1, characterized in that, It further includes a driving unit used for driving the relative movement of the upper die member and the lower die member.

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