Planetary carrier blank forging apparatus and forging method

Abstract

The present application belongs to the field of forging technology, and provides a planetary carrier blank forging equipment and a forging method thereof. The planetary carrier blank forging equipment comprises an upper die and a lower die. The bottom surface of the upper die is provided with a protruding center column. The top surface of the lower die is provided with a recessed groove I. An active ring which can move axially is arranged outside the center column. The sidewall of the active ring is provided with a groove III. A pin shaft which can swing is arranged on the lower die. The pin shaft can be switched between an unlocked state and a locked state. During the switching process from the unlocked state to the locked state, the free end of the pin shaft gradually enters the groove I. When the upper die and the lower die are closed, a forging cavity of the planetary carrier blank is formed between the center column, the groove I and the active ring. After the upper die and the lower die are closed, the pin shaft is switched from the unlocked state to the locked state, so that the free end of the pin shaft is embedded in the groove III, and the free end of the pin shaft remains embedded in the groove III for a period of time during the separation process of the upper die and the lower die.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of forging, and particularly relates to a planetary carrier blank forging equipment and a forging method thereof. BACKGROUND

[0002] The planetary carrier is one of the core components of planetary gear transmission, and is generally made through a forging process. In the die forging process, when the thickness of the planetary carrier is large, the cavity of the corresponding die is deep. If the cavity body is arranged in the upper die or the lower die, the forging part will be stuck in the die due to the deformation of the blank filling the cavity during forging. The die with a composite structure, including a cavity with a spring structure and a cavity with a separable structure, can solve this problem to some extent. However, the die with a composite structure has the problems of complex structure, difficulty in design, manufacture and maintenance, and forming precision caused by dimensional error and matching error of the structure. Moreover, when the planetary carrier with a large structure size is manufactured, the spring structure of the die with a composite structure will fail and the die will be stuck due to the large weight of the forging part. SUMMARY

[0003] To solve the above technical problems, the application provides a planetary carrier blank forging equipment and a forging method thereof, and the specific technical solutions are as follows.

[0004] In a first aspect, the application provides a planetary carrier blank forging equipment, which comprises an upper die and a lower die. The bottom surface of the upper die has a protruding center column, and the top surface of the lower die has a recessed groove one.

[0005] An active ring axially movable is arranged outside the center column, and the side wall of the active ring has a groove three. A pin shaft swingable is arranged on the lower die, and the pin shaft is switched between an unlocked state and a locked state. During the switching process from the unlocked state to the locked state, the free end of the pin shaft gradually enters the groove one.

[0006] When the upper die and the lower die are closed, a forging cavity of the planetary carrier blank is formed between the center column, the groove one and the active ring.

[0007] After the upper die and the lower die are closed, the pin shaft is switched from the unlocked state to the locked state, so that the free end of the pin shaft is embedded in the groove three, and the free end of the pin shaft remains embedded in the groove three for a period of time during the separation of the upper die and the lower die.

[0008] In an optional embodiment, a positioning hole is arranged beside the pin shaft. When the pin shaft is in the unlocked state, the pin shaft partially covers the positioning hole. When the pin shaft is in the locked state, the positioning hole is completely exposed.

[0009] The upper die is provided with a positioning pin matched with the positioning hole, the positioning pin comprises a positioning section and a control section, when the upper die is combined with the lower die and the pin shaft is in the unlocking state, the positioning section can be freely inserted into the positioning hole, and the pin shaft will hinder the control section from being inserted into the positioning hole.

[0010] In an alternative embodiment, the cross section of the control section is the same as the positioning hole, and the cross section of the positioning section is the same as the shape of the positioning hole exposed when the pin shaft is in the unlocking state.

[0011] In an alternative embodiment, after the upper die is combined with the lower die, the depth of the control section inserted into the positioning hole is greater than the thickness of the pin shaft.

[0012] In an alternative embodiment, the upper die is fixed with a telescopic controller, the telescopic controller has a telescopic rod, and the telescopic rod is fixed with the positioning pin.

[0013] In an alternative embodiment, a sensor is arranged between the upper die and the lower die, the sensor monitors the combined state of the upper die and the lower die and generates a control signal for the telescopic controller.

[0014] In an alternative embodiment, the groove bottom of the groove one has a recessed groove two, the cross section of the groove two is the same as the center column, and when the upper die is combined with the lower die, the lower end of the center column is located in the groove two.

[0015] In an alternative embodiment, the lower end face of the center column is provided with a chamfer.

[0016] In an alternative embodiment, the top of the movable ring is connected with the upper die through a return spring.

[0017] In a first aspect, the application provides a planet carrier blank forging method, the forging method is used for the planet carrier blank forging device, and the forging method is as follows:

[0018] Placing an annular blank in the groove one;

[0019] Controlling the upper die to be combined with the lower die;

[0020] After the upper die is combined with the lower die, controlling the pin shaft to rotate and become the locking state;

[0021] Controlling the upper die to be separated from the lower die, so that the planet carrier blank is actively separated from the center column until the pin shaft is reset.

[0022] The application has the following beneficial effects:

[0023] (1) High-efficiency demolding: The linkage design of the movable ring and the stopper is adopted, the movable ring is automatically locked when the mold is closed, and the forged piece and the center column are forcibly separated when the mold is opened, solving the problem of friction between the forged piece and the mold caused by the expansion ring process;

[0024] (2) Improve forming precision: The structure of the center column and the groove is adopted to form the forming cavity, which can improve the precision of the forged piece while solving the demolding problem of the forged piece, and avoid the size error and matching error of the composite mold structure, which can cause the forming precision problem;

[0025] (3) Simple structure and efficient control: Based on the traditional structure of positioning pin and positioning hole, through the structural improvement of the positioning pin and the position setting of the positioning hole, the linkage of the movable ring and the stopper can be controlled while meeting the positioning requirement; BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The structure of the upper die and the lower die is shown;

[0027] Figure 2 The structure of the upper die is shown;

[0028] Figure 3 The structure of the lower die is shown;

[0029] Figure 4 The schematic diagram of the pin shaft in different positions is shown;

[0030] Figure 5 The structure of the positioning pin is shown. DETAILED DESCRIPTION

[0031] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments. However, one skilled in the art will understand that the application can be practiced without these details. In other instances, well-known structures have not been described in detail in order to avoid unnecessarily obscuring the description of the embodiments. Unless the context requires otherwise, throughout the specification and claims that follow, the word "comprise" is to be construed in an open, inclusive and

[0032] The planetary carrier blank forging device described in the present application is used for forging a planetary carrier blank, and a ring-shaped blank, so as to facilitate subsequent heat treatment and finishing. In particular, the present application mainly proposes a special forging die for forging a planetary carrier blank. Referring to Figure 1 , the structure of the planetary carrier blank forging device (die part) of the present application is shown.

[0033] The planet carrier blank forging device of the present application comprises an upper die 100 and a lower die 200, generally the lower die 200 is fixed on a machine tool, the upper die 100 is movable and controlled by a hydraulic machine to move up and down, when the upper die 100 moves down to close with the lower die 200, the raw material placed in the lower die 200 can be forged into a planet carrier blank, correspondingly, when the upper die 100 closes with the lower die 200, a cavity corresponding to the planet carrier blank is formed inside.

[0034] In combination Figure 1 The bottom surface of the upper die 100 has a protruding center column 101, the top surface of the lower die 200 has a recessed groove 201, the groove bottom of the groove 201 has a recessed groove 202, the diameter of the groove 202 is smaller than that of the groove 201 so that the groove 201 and the groove 202 form a stepped structure, the diameter of the center column 101 is the same as that of the groove 202, so that when the upper die 100 closes with the lower die 200, the lower end of the center column 101 enters the inside of the groove 202, a cavity for forging the planet carrier blank is formed between the center column 101 and the groove wall of the groove 201, here the distance of the protruding center column 101 from the bottom surface of the upper die 100 should be less than or equal to the sum of the depths of the groove 201 and the groove 202.

[0035] In a forging mode, an annular blank is placed in the groove 201, the inner diameter of the annular blank is smaller than the actual required inner diameter of the planet carrier blank, correspondingly, the outer diameter of the annular blank is also or can be smaller than the actual required inner diameter of the planet carrier blank, when the upper die 100 moves down, the center column 101 enters the center hole of the annular blank, contacts and extrudes the annular blank, so that the annular blank expands to a certain extent, until the final forging is completed when the dies are completely closed, so that the annular blank becomes the required planet carrier blank.

[0036] In order to facilitate the center column 101 to enter the center hole of the annular blank when the upper die 100 moves down, a chamfer 102 is provided on the outer periphery of the lower end surface of the center column 101; since the lower end of the center column 101 enters the groove 202 beyond the groove 201 when the dies are completely closed, the center hole can ensure the forging requirements of the inner hole of the blank.

[0037] In another embodiment, the structure of the groove 202 can also be cancelled, that is, only the groove 201 and the center column 101 are provided, at this time the diameter of the center column 101 should be smaller than that of the groove 201, and the distance of the protruding center column 101 from the bottom surface of the upper die 100 should be equal to the depth of the groove 201, that is, the ground surface of the center column 101 should contact the groove bottom of the groove 201 when the dies are completely closed. And this structure is not suitable for forging that requires large size deformation.

[0038] It should be noted that the whole process of the planet carrier is complex, even the forging is not one-step forming, but generally consists of upsetting, punching, multi-pass hole expanding and other processes from a solid cylindrical raw material, and the planet carrier blank forging equipment of the application is particularly suitable for the forging demand of hole expansion.

[0039] In an embodiment, the planet carrier blank forging equipment further comprises an auxiliary separation assembly, which comprises a movable ring 310 arranged on the upper die 100 and a stopper arranged in the lower die 200 and used in cooperation with the movable ring 310. Referring to Figure 2 , the movable ring 310 is slidingly sleeved on the center column 101 and can move along the axial direction of the center column 101 under the action of an external force, and the outer diameter of the movable ring 310 is the same as the diameter of the groove one 201, so that when the upper die 100 and the lower die 200 are closed, the movable ring 310 enters the groove one 201 entirely or partially, and when the upper die 100 and the lower die 200 are separated by the action of the stopper on the movable ring 310, the movable ring 310 still remains in the groove one 201, and then the formed planet carrier blank is separated from the center column 101, so as to solve the problem that the planet carrier blank is difficult to demold due to excessive friction between the center column 101 and the annular blank when the center column 101 extrudes the annular blank.

[0040] Referring to Figure 3 , when the upper die 100 and the lower die 200 are separated by the action of the stopper on the movable ring 310, the movable ring 310 still remains in the groove one 201, which is realized by the cooperation between the position change of the stopper and the structure of the movable ring 310. The stopper comprises a pin shaft 320, the pin shaft 320 has a rotating shaft so that the pin shaft 320 can rotate around the rotating shaft to change its position, and the pin shaft 320 has two states according to the different positions, including an unlocked state and a locked state. In the unlocked state, the pin shaft 320 is accommodated in the main body of the lower die 200, and in the locked state, the pin shaft 320 extends its free end (relative to the rotating end) into the groove one 201 due to rotation, and the side wall of the movable ring 310 has a groove three 311 matched with the pin shaft 320.

[0041] When the upper die 100 and the lower die 200 are closed, the movable ring 310 is in the position state shown in Figure 3 , the pin shaft 320 rotates under the action of an external force to change from the unlocked state to the locked state, and the end of the pin shaft 320 extends into the groove three 311 to limit the movable ring 310, so that when the upper die 100 and the lower die 200 are separated, the movable ring 310 still remains in the groove one 201.

[0042] In order to facilitate installation, fixation, maintenance and other operations, a sealing plate 330 is further arranged, which is fixed with the lower die 200 to hide the pin shaft 320 inside, achieving the purpose of fixation and protection, and the sealing plate 330 and the lower die 200 can be fixed by means of a countersunk head bolt connection.

[0043] Referring to Figure 4 , two different states of the pin shaft 320 (320a, 320b) are shown, wherein 320a is the locked state and 320b is the unlocked state, and a positioning hole 210 is arranged beside the pin shaft 320, and a positioning pin 110 is arranged on the upper die 100, when the upper die 100 and the lower die 200 are closed, the positioning pin 110 is inserted into the positioning hole 210, which assists the positioning of the upper die 100 and the lower die 200 and maintains the stability of the closed upper die 100 and lower die 200, and the positioning pin 110 also controls the pin shaft 320 to change from the unlocked state to the locked state according to different insertion states in the positioning hole 210.

[0044] In combination Figure 4 , when the pin shaft 320 is in the unlocked state, the pin shaft 320 partially covers the positioning hole 210, and when the pin shaft 320 is in the locked state, the positioning hole 210 is completely exposed.

[0045] In combination Figure 5 , the positioning pin 110 includes a positioning section 111 and a control section 112, wherein the cross section of the control section 112 is the same as that of the positioning hole 210, and the cross section of the positioning section 111 is smaller than that of the control section 112 and the same as the shape of the positioning hole 210 when the pin shaft 320 is in the unlocked state. During the closing process of the upper die 100 and the lower die 200, the positioning section 111 first enters the positioning hole 210 and does not contact and press the pin shaft 320, and after the upper die 100 and the lower die 200 are completely closed, the control section 112 is inserted into the positioning hole 210 and contacts and presses the pin shaft 320, so that the pin shaft 320 rotates and changes to the locked state.

[0046] In particular, the depth of the control section 112 inserted into the positioning hole 210 is greater than the thickness of the pin shaft 320, so that when the upper die 100 and the lower die 200 are separated, as the upper die 100 is lifted, the control section 112 is still in the positioning hole 210, thereby keeping the pin shaft 320 in the locked state, that is, the movable ring 310 is still kept in the groove one 201, so that the planetary carrier blank and the center column 101 are actively separated, until the control section 112 is completely separated from the positioning hole 210, the pin shaft 320 is reset to the unlocked state, and the movable ring 310 can be separated from the groove one 201.

[0047] In order to provide power for resetting the pin shaft 320, a torsional spring can be arranged at the rotation of the pin shaft 320, or an elastic spring sheet can be arranged between the pin shaft 32 and the lower die 200, both of which provide force to keep the pin shaft 320 in the unlocked state, and the detailed setting structures of the two are not described here.

[0048] To provide power for the reset of the movable ring 310, a reset spring can be fixed on the top of the movable ring 310 and fixed with the upper die 100, and a slot can be opened on the bottom of the upper die 100 to hide the reset spring. When the pin shaft 320 is reset to the unlocked state, the movable ring 310 is released from the reset by the elastic force of the reset spring in the slot 201.

[0049] The air cylinder 120 is also fixed on the upper die 100, and the telescopic rod of the air cylinder 120 is connected with the positioning pin 110 inside the upper die 100. The movement state of the positioning pin 110 is controlled by the air cylinder 120, that is, the air cylinder 120 is in the retracted state during the clamping process, so that the control section 112 is accommodated in the upper die 100. After the clamping is completed, the air cylinder 120 is in the extended state, so that the control section 112 extends out of the upper die 100 and enters the positioning hole 210. Correspondingly, the upper die 100 has a cavity for accommodating the telescopic rod of the air cylinder 120 and the reciprocating movement of the positioning pin 110.

[0050] The air cylinder 120 can also be replaced by an oil cylinder, an electric cylinder, or other telescopic controllers.

[0051] A sensor can be arranged on the contact surface of the upper die 100 and the lower die 200, which is used to detect the clamping state of the upper die 100 and the lower die 200, such as a distance sensor, a grating sensor, etc. The relative position, relative distance, relative light intensity, and other factors are changed when the upper die 100 and the lower die 200 are clamped, so as to form a control signal to control the action of the air cylinder 120.

[0052] The application also provides a planet carrier blank forging method, which is used for the planet carrier blank forging device described above, and the method is as follows:

[0053] The annular blank is placed in the slot 201;

[0054] The upper die 100 and the lower die 200 are controlled to be clamped;

[0055] When the upper die 100 and the lower die 200 are clamped, the positioning pin 110 is controlled to move downward to press the pin shaft 320, so that the pin shaft 320 rotates to become the locked state;

[0056] The upper die 100 and the lower die 200 are controlled to be separated, so that the planet carrier blank and the center column 101 are actively separated until the pin shaft 320 is reset, and the positioning pin 110 is controlled to move upward to reset.

[0057] The above embodiments are only used to illustrate the technical solutions of the application, and not to limit them.

Claims

1. A planetary carrier blank forging apparatus comprising an upper die and a lower die, characterized in that, The bottom surface of the upper die has a convex center column, and the top surface of the lower die has a concave groove one; An axially movable movable ring is arranged outside the center column, and the side wall of the movable ring has a groove three; a swingable pin shaft is arranged on the lower die, and the pin shaft is switched between an unlocked state and a locked state by swinging, and during the switching of the pin shaft from the unlocked state to the locked state, the free end of the pin shaft gradually enters the groove one; When the upper die and the lower die are closed, a forging cavity of the planetary carrier blank is formed between the center column, the groove one and the movable ring; After the upper die and the lower die are closed, the pin shaft is switched from the unlocked state to the locked state, so that the free end of the pin shaft is embedded in the groove three, and the free end of the pin shaft remains embedded in the groove three for a period of time during the separation of the upper die and the lower die; A positioning hole is arranged beside the pin shaft, and when the pin shaft is in the unlocked state, the pin shaft partially covers the positioning hole; when the pin shaft is in the locked state, the positioning hole is completely exposed; A positioning pin matched with the positioning hole is arranged on the upper die, and the positioning pin includes a positioning section and a control section; when the upper die and the lower die are closed and the pin shaft is in the unlocked state, the positioning section can be freely inserted into the positioning hole, and the control section is prevented from being inserted into the positioning hole by the pin shaft; The cross section of the control section is the same as the positioning hole, and the cross section of the positioning section is the same as the shape of the positioning hole exposed when the pin shaft is in the unlocked state; After the upper die and the lower die are closed, the depth of the control section inserted into the positioning hole is greater than the thickness of the pin shaft; A telescopic controller is fixed on the upper die, and the telescopic controller has a telescopic rod which is fixed with the positioning pin.

2. The planetary carrier blank forging apparatus according to claim 1, characterized by, A sensor is arranged between the upper die and the lower die, and the sensor monitors the closing state of the upper die and the lower die and generates a control signal for the telescopic controller.

3. The planetary carrier blank forging apparatus according to claim 1, characterized by, The groove bottom of the groove one has a concave groove two, the cross section of the groove two is the same as the center column, and when the upper die and the lower die are closed, the lower end of the center column is located in the groove two.

4. The planetary carrier blank forging apparatus according to claim 3, characterized by, An outer periphery of the lower end surface of the center column is provided with a chamfer.

5. The planetary carrier blank forging apparatus of claim 1, wherein, The top of the movable ring is connected with the upper die through a return spring.

6. A planetary carrier blank forging method characterized by, The forging method is applied to the planetary carrier blank forging equipment of any one of claims 1-5, and the forging method is: Place the annular blank in the groove one; Control the closing of the upper die and the lower die; After the upper die and the lower die are closed, control the pin shaft to rotate to become the locked state; Control the separation of the upper die and the lower die, so that the planetary carrier blank and the center column are actively separated until the pin shaft is reset.

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