Hollow spline shaft yoke blank forging die and forging process

Abstract

The invention relates to a hollow spline shaft yoke blank forging die and a forging process. The forging die comprises a lower die, an upper die and a driving device. A lower die cavity and a plurality of lower slideways are arranged at the top of the lower die; a die rod is slidably arranged in the lower slide way, and one end of the lower slide way communicates with the lower die cavity. The upper die is arranged above the lower die, an upper die cavity and upper slideways in one-to-one correspondence with the lower slideways are arranged at the bottom of the upper die, the upper die cavity is matched with the lower die cavity, and a driving device matched with the upper slideways and the lower slideways is used for driving the upper die to move downwards and driving the die rod to move towards the lower die cavity; by arranging the multiple die rods, flash-free forging of the complex spline shaft fork can be completed through one-time heating, preferably, the die rods correspond to the deep hole in the end of the shaft part of the shaft fork and the two through holes in the fork part of the shaft fork correspondingly, a shaft fork blank with the shaft part and the fork part at the same time can be completed, the deep hole is formed in the shaft part, and the through holes are formed in the fork part; the shape of the blank is closer to that of a finished product, the feeding weight is light, the forming quality is good, and the forming precision is high.

Description

Technical Field

[0001] The invention relates to the technical field of forging a hollow spline shaft yoke blank, and in particular to a hollow spline shaft yoke blank forging die and a forging process. Background Art

[0002] At present, the spline shaft forks used in automobile transmission shafts are mainly solid one-piece and friction welded (the shaft fork head and shaft tube are friction welded), and are basically made by traditional forging technology. The traditional forging process route is: cutting → heating → blanking → heating → pre-forging → final forging → trimming → quenching and tempering → shot blasting. The traditional forging process requires 2 heatings and 9 processes, with high production costs and low production efficiency. At the same time, a large amount of trimming waste and oxidation burning will be generated. Although the traditional forging process can meet the needs, due to the need for two heatings and numerous processes, the traditional process generates a lot of waste from the flash, high energy consumption and cost, and heavy blank weight. Summary of the invention

[0003] Based on the above description, the present invention provides a hollow spline shaft fork blank forging die and forging process, and by setting a plurality of die rods, the flash-free forging of a complex spline shaft fork can be completed by heating at one time. Preferably, the die rods correspond to the deep hole at the end of the shaft portion of the shaft fork and the two through holes in the fork portion of the shaft fork, respectively, and a shaft fork blank having both a shaft portion and a fork portion can be completed, and the end of the shaft portion is provided with a deep hole, and the fork portion is provided with a through hole, the shape of the blank is closer to the shape of the finished product, and the feed weight is light, the forming quality is good, and the forming precision is high.

[0004] The technical solution of the present invention to solve the above technical problem is as follows: a hollow spline shaft fork blank forging die, including a lower die, an upper die and a driving device; The top of the lower mold is provided with a lower mold cavity and a plurality of lower slides; a mold rod is slidably provided in the lower slide, and one end of the lower slide is connected to the lower mold cavity; The upper mold is arranged above the lower mold, and the bottom of the upper mold is provided with an upper mold cavity and an upper slideway corresponding to the lower slideway one by one, the upper mold cavity is used to form a complete closed mold cavity with the lower mold cavity, and the upper slideway is used to form a complete slideway matched with the mold rod with the lower slideway; The driving device is used to drive the upper mold to move downward, and drive the mold rod to move toward the lower mold cavity.

[0005] Based on the above technical solution, the present invention can also be improved as follows.

[0006] Furthermore, the top of the lower mold cavity is provided with three lower slides and mold rods, and the mold rods correspond to the deep hole at the end of the shaft fork shaft portion and the two through holes of the shaft fork fork portion respectively.

[0007] Further, the driving device includes a cylinder body, and the cylinder body is arranged above the upper mold; An outer piston rod is arranged in the cylinder body, the top of the outer piston rod is open, and an outer piston plate is arranged on the outer side of the top of the outer piston rod, and the outer piston plate is slidably sealed with the inner side wall of the cylinder body; a push plate is arranged at the bottom of the outer piston rod, and push rods corresponding to the mold rods are arranged at the bottom of the push plate, and the bottoms of the push rods can slidably pass through the upper mold, and the push rods are respectively used to push the corresponding mold rods; An inner piston rod is arranged in parallel inside the outer piston rod, an inner piston plate is arranged on the top of the inner piston rod, and the inner piston plate is slidably sealed with the inner side wall of the outer piston rod; the bottom of the inner piston rod can slidably pass through the push plate and is connected to the upper die; The outer piston rod is provided with a slot, a trigger block which can move radially is provided in the slot, a block matching the slot is elastically provided at the bottom of the cylinder body, and when the upper mold and the lower mold are closed, the inner piston plate presses the block out of the slot through the trigger block.

[0008] Furthermore, the bottom of the outer piston plate is connected to the cylinder body via a first elastic member, and the first elastic member is used to push the outer piston plate upward.

[0009] Furthermore, a first inclined surface is provided at one end of the mold rod away from the lower mold cavity, and the top of the first inclined surface is inclined toward the side close to the lower mold cavity; and a second inclined surface matching the first inclined surface is provided at the bottom of the push rod.

[0010] Furthermore, a buffer groove matching the push rod is provided at the bottom of one end of the lower slide away from the lower mold cavity.

[0011] Furthermore, the bottom of the inner piston plate is connected to the push plate via a second elastic member, and the second elastic member is used to push the inner piston plate upward.

[0012] Furthermore, the mold rods are connected to the lower mold via a third elastic member, and the third elastic member is used to push the mold rods in a direction away from the lower mold cavity.

[0013] The present invention also proposes a hollow spline shaft fork blank forging process, comprising the following steps: (1) Cut the raw steel bars into bars of specified length using a high-speed circular saw according to the required length and weight; (2) Place the bar of specified cutting length into the medium frequency heating furnace for heating; (3) Remove the oxide scale from the bar after it is removed from the heating furnace; (4) The bar material with the oxide scale removed is placed in the closed die cavity of the hydraulic forging machine, and the hydraulic press is started. The punch squeezes the bar material into the die cavity, so that the die forging and extrusion are performed simultaneously to form a blank, and a shaft fork blank having both a shaft and a fork is generated, and a deep hole is provided at the end of the shaft, and a through hole is provided on the fork; (5) The blank is tempered and shot blasted.

[0014] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: 1. The present invention can complete the flash-free forging of a complex spline shaft fork by setting a plurality of die rods in one heating. Preferably, the die rods correspond to the deep hole at the end of the shaft fork and the two through holes at the fork of the shaft fork respectively, so that a shaft fork blank having both a shaft and a fork can be completed, and the end of the shaft is provided with a deep hole, and the fork is provided with a through hole, so that the shape of the blank is closer to the shape of the finished product, and the weight of the feed is light, the forming quality is good, and the forming precision is high; 2. By arranging an outer piston rod and an inner piston rod in the cylinder body of the driving device, the upper and lower molds can be closed step by step through one cylinder body, and then the mold rod can be extended into the mold cavity, which simplifies the control process of the driving device and is more convenient to control; 3. The forging process only requires one heating and does not require trimming of the blank, which improves the production efficiency of the blank and reduces the production cost of the blank. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a blank completed in an embodiment of the present invention; Figure 2 A schematic structural diagram of a hollow spline shaft fork blank forging die and forging process provided in an embodiment of the present invention; Figure 3 A schematic top view of the lower mold in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the driving device before working in an embodiment of the present invention; Figure 5 It is a schematic diagram of the structure of the driving device after the upper and lower molds are closed in an embodiment of the present invention; Figure 6 It is a schematic diagram of the structure after the mold rod of the driving device in the embodiment of the present invention extends into the mold cavity; In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Lower die; 11. Lower die cavity; 12. Lower slide; 13. Die rod; 14. Third elastic member; 15. Buffer groove; 2. Upper die; 21. Upper die cavity; 22. Upper slide; 3. Cylinder body; 31. Block; 4. Outer piston rod; 41. Outer piston plate; 42. First elastic member; 43. Push plate; 44. Push rod; 45. Block; 46. Trigger block; 5. Inner piston rod; 51. Inner piston plate; 52. Second elastic member; 6. Blank; 61. Shaft; 62. Deep hole; 63. Fork; 64. Through hole. DETAILED DESCRIPTION

[0016] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0018] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0019] Embodiment 1 A hollow spline shaft fork blank 6 forging die, such as Figure 2 As shown, it includes a lower mold 1, an upper mold 2 and a driving device.

[0020] The top of the lower mold 1 is provided with a lower mold cavity 11 and a plurality of lower slideways 12. A mold rod 13 is slidably provided in the lower slideway 12, and one end of the lower slideway 12 is connected to the lower mold cavity 11.

[0021] The upper mold 2 is arranged above the lower mold 1, and the bottom of the upper mold 2 is provided with an upper mold cavity 21 and an upper slide 22 corresponding to the lower slide 12. The upper mold cavity 21 is used to form a complete closed mold cavity with the lower mold cavity 11, and the upper slide 22 is used to form a complete slide matching the mold rod 13 with the lower slide 12.

[0022] The driving device is used to drive the upper mold 2 to move downward, and drive the mold rod 13 to move toward the lower mold cavity 11.

[0023] This embodiment, by providing a plurality of die rods 13, can complete the flash-free forging of a complex spline shaft fork by heating at one time.

[0024] In this embodiment, Figure 3 As shown, three lower slides 12 and a mold rod 13 are provided on the top of the lower mold cavity 11, and the mold rod 13 corresponds to the deep hole 62 at the end of the shaft fork shaft portion 61 and the two through holes 64 of the shaft fork fork portion 63 respectively.

[0025] Therefore, the forging die of this embodiment can complete the following Figure 1 The blank 6 shown has both a shaft portion 61 and a fork portion 63, and a deep hole 62 is provided at the end of the shaft portion 61, and a through hole 64 is provided on the fork portion 63. The shape of the blank 6 is closer to the shape of the finished product, and the feed weight is light, the forming quality is good, and the forming precision is high.

[0026] Preferably, Figures 4 to 6 As shown, the driving device includes a cylinder body 3, and the cylinder body 3 is arranged above the upper mold 2.

[0027] An outer piston rod 4 is arranged in the cylinder body 3, the top of the outer piston rod 4 is open, and an outer piston plate 41 is arranged on the outer side of the top of the outer piston rod 4, the outer piston plate 41 is slidably sealed with the inner wall of the cylinder body 3, and the bottom of the outer piston plate 41 is connected to the cylinder body 3 through a first elastic member 42, and the first elastic member 42 is used to push the outer piston plate 41 upward.

[0028] A push plate 43 is provided at the bottom of the outer piston rod 4, and a push rod 44 corresponding to the mold rod 13 is provided at the bottom of the push plate 43. The bottom of the push rod 44 can slide through the upper mold 2, and the push rod 44 is used to push the corresponding mold rod 13. A first inclined surface is provided at the end of the mold rod 13 away from the lower mold cavity 11, and the top of the first inclined surface is inclined toward the side close to the lower mold cavity 11. A second inclined surface matching the first inclined surface is provided at the bottom of the push rod 44. A buffer groove 15 matching the push rod 44 is provided at the bottom of the end of the lower slide 12 away from the lower mold cavity 11. The mold rods 13 are connected to the lower mold 1 through a third elastic member 14, and the third elastic member 14 is used to push the mold rod 13 in a direction away from the lower mold cavity 11.

[0029] An inner piston rod 5 is arranged in parallel inside the outer piston rod 4, and an inner piston plate 51 is arranged on the top of the inner piston rod 5, and the inner piston plate 51 is slidably sealed with the inner side wall of the outer piston rod 4. The bottom of the inner piston rod 5 can slide through the push plate 43 and is connected to the upper mold 2. The bottom of the inner piston plate 51 is connected to the push plate 43 through the second elastic member 52, and the second elastic member 52 is used to push the inner piston plate 51 upward.

[0030] When the pressure inside the cylinder body 3 is increased, the outer piston plate 41 moves downward due to the block 31 being inserted into the groove 45. The gradually increasing pressure first pushes the inner piston plate 51 downward to close the upper and lower molds 1.

[0031] After the upper and lower molds 1 are closed, the inner piston plate 51 presses the block 31 out of the slot 45 through the trigger block 46, and the outer piston plate 41 starts to move downward. At this time, the push rod 44 pushes the mold rod 13 into the mold cavity until the push rod 44 passes through the mold rod 13 and enters the buffer groove 15. At this time, the push rod 44 prevents the mold rod 13 from resetting, so that the mold rod 13 remains in the mold cavity.

[0032] After the forging is completed, the cylinder 3 is depressurized, and the outer piston plate 41 , the inner piston plate 51 and the die rod 13 are reset under the action of the first elastic member 42 , the second elastic member 52 and the third elastic member 14 , respectively.

[0033] This embodiment arranges an outer piston rod 4 and an inner piston rod 5 in the cylinder body 3 of the driving device, so that the upper and lower molds 1 can be closed step by step through one cylinder body 3, and then the mold rod 13 can be extended into the mold cavity, which simplifies the control process of the driving device and is more convenient to control.

[0034] Embodiment 2 A hollow spline shaft fork blank forging process comprises the following steps: (1) Cut the raw steel bars into bars of specified length using a high-speed circular saw according to the required length and weight; (2) Place the bar of specified cutting length into the medium frequency heating furnace for heating; (3) Remove the oxide scale from the bar after it is removed from the heating furnace; (4) The bar material with the oxide scale removed is placed in the closed die cavity of the hydraulic forging machine, and the hydraulic press is started. The punch squeezes the bar material into the die cavity, so that the die forging and extrusion are performed simultaneously to form a blank, and a shaft fork blank having both a shaft and a fork is generated, and a deep hole is provided at the end of the shaft, and a through hole is provided on the fork; (5) The blank is tempered and shot blasted.

[0035] The forging process of this embodiment only requires one heating and does not require trimming of the blank, thereby improving the production efficiency of the blank and reducing the production cost of the blank.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hollow spline shaft fork blank forging die, characterized in that: It includes a lower die, an upper die and a driving device; The top of the lower mold is provided with a lower mold cavity and a plurality of lower slides; a mold rod is slidably provided in the lower slide, and one end of the lower slide is connected to the lower mold cavity; The upper mold is arranged above the lower mold, and the bottom of the upper mold is provided with an upper mold cavity and an upper slideway corresponding to the lower slideway one by one, the upper mold cavity is used to form a complete closed mold cavity with the lower mold cavity, and the upper slideway is used to form a complete slideway matched with the mold rod with the lower slideway; The driving device is used to drive the upper mold to move downward, and drive the mold rod to move toward the lower mold cavity.

2. A hollow spline shaft yoke blank forging die according to claim 1, characterized in that: The top of the lower mold cavity is provided with three lower slides and the mold rods, and the mold rods correspond to the deep hole at the end of the shaft fork shaft portion and the two through holes of the shaft fork fork portion respectively.

3. The hollow spline shaft yoke blank forging die according to claim 1, characterized in that: The driving device comprises a cylinder body, and the cylinder body is arranged above the upper mold; An outer piston rod is arranged in the cylinder body, the top of the outer piston rod is open, and an outer piston plate is arranged on the outer side of the top of the outer piston rod, and the outer piston plate is slidably sealed with the inner side wall of the cylinder body; a push plate is arranged at the bottom of the outer piston rod, and push rods corresponding to the mold rods are arranged at the bottom of the push plate, and the bottoms of the push rods can slidably pass through the upper mold, and the push rods are respectively used to push the corresponding mold rods; An inner piston rod is arranged in parallel inside the outer piston rod, an inner piston plate is arranged on the top of the inner piston rod, and the inner piston plate is slidably sealed with the inner side wall of the outer piston rod; the bottom of the inner piston rod can slidably pass through the push plate and is connected to the upper die; The outer piston rod is provided with a slot, a trigger block which can move radially is provided in the slot, a block matching the slot is elastically provided at the bottom of the cylinder body, and when the upper mold and the lower mold are closed, the inner piston plate presses the block out of the slot through the trigger block.

4. A hollow spline shaft yoke blank forging die according to claim 3, characterized in that: The bottom of the outer piston plate is connected to the cylinder body via a first elastic member, and the first elastic member is used to push the outer piston plate upward.

5. The hollow spline shaft yoke blank forging die according to claim 3, characterized in that: A first inclined surface is arranged at one end of the mold rod away from the lower mold cavity, and the top of the first inclined surface is inclined toward the side close to the lower mold cavity; a second inclined surface matching the first inclined surface is arranged at the bottom of the push rod.

6. The hollow spline shaft yoke blank forging die according to claim 3, characterized in that: A buffer groove matching the push rod is arranged at the bottom of one end of the lower slide away from the lower die cavity.

7. The hollow spline shaft yoke blank forging die according to claim 3, characterized in that: The bottom of the inner piston plate is connected to the push plate via a second elastic member, and the second elastic member is used to push the inner piston plate upward.

8. The hollow spline shaft yoke blank forging die according to claim 1, characterized in that: The mold rods are connected to the lower mold via a third elastic member, and the third elastic member is used to push the mold rods in a direction away from the lower mold cavity.

9. A hollow spline shaft fork blank forging process, characterized in that: The following steps are involved: (1) Cut the raw steel bars into bars of specified length using a high-speed circular saw according to the required length and weight; (2) Place the bar of specified cutting length into the medium frequency heating furnace for heating; (3) Remove the oxide scale from the bar after it is removed from the heating furnace; (4) The bar material with the oxide scale removed is placed in the closed die cavity of the hydraulic forging machine, and the hydraulic press is started. The punch squeezes the bar material into the die cavity, so that the die forging and extrusion are performed simultaneously to form a blank, and a shaft fork blank having both a shaft and a fork is generated, and a deep hole is provided at the end of the shaft, and a through hole is provided on the fork; (5) The blank is tempered and shot blasted.

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