CN215918978U - Synchronous extrusion forming device for tooth profile and internal spline of parking gear - Google Patents

Abstract

The utility model discloses a parking tooth shape and internal spline synchronous extrusion forming device which comprises an upper die and a lower die, wherein an extrusion cavity corresponding to the upper die is arranged in the middle of the upper die, a circle of rectangular teeth are arranged on the inner wall of the extrusion cavity, a male die is arranged in the extrusion cavity, a circle of external splines are arranged on the periphery of the male die, a lubricated annular blank is placed in the extrusion cavity, an inner hole of the annular blank is correspondingly placed on the male die, the lower die is used for extruding the annular blank in the extrusion cavity, cold extrusion forming of the rectangular teeth and the internal splines is simultaneously completed, and the extrusion process is a continuous extrusion form. Just so can guarantee that the axis of parking tooth hole is in same axis with the axis of cyclic annular blank when the extrusion of cyclic annular blank, guarantee that the axiality is unanimous.

Description

Synchronous extrusion forming device for tooth profile and internal spline of parking gear

Technical Field

The utility model relates to the technical field of automobile part processing, in particular to a synchronous extrusion forming device for a parking tooth profile and an internal spline.

Background

The existing pure electric or hybrid new energy automobiles are all provided with an electric drive power assembly, the electric drive power assembly comprises a motor and a speed reducer, and an output shaft (or a rotating shaft) of the motor is connected with an input shaft of the speed reducer to transmit torque.

In the existing speed reducer, some speed reducers are provided with a parking gear for braking when a vehicle stops so as to prevent the vehicle from sliding (P gear), and the parking gear can prevent a transmission part from rotating when being locked. The parking gear is generally arranged on an intermediate shaft or an output differential, is subjected to large torque and impact load, and can cause serious consequences once tooth surface pitting or tooth root crack failure occurs, so that the material development, the manufacturing process, the gear detection and the bench test for the parking gear are all very strict.

The parking gear is generally manufactured into an annular blank by adopting a hot forging process, as shown in figure 1, finish turning is carried out after isothermal normalizing, cylindrical rectangular teeth of the parking gear are processed by adopting hobbing, then a pull pin spline is carried out, and finally the tooth shape is ground after carburizing and quenching; the gear precision reaches 6 grades of precision, so the processing cost is higher, the gear processing cost can be greatly reduced by adopting a cold extrusion or cold finishing process to replace a hobbing process at present, but the following technical problems still exist:

1. in the processing technology of the parking gear in the prior art, the gear hobbing is adopted to process the excircle rectangular gear of the parking gear, and then the internal spline of the parking gear is processed, so that two procedures are needed to complete the forming processing of the parking gear, thus the processing period is long and the processing efficiency is low;

2. even though the excircle rectangle tooth with the gear hobbing processing parking tooth among the prior art more replaces to adopt the cold extrusion mode to excircle rectangle tooth processing, nevertheless, still need fix a position the parking tooth alone to carry out the broach spline to the circle in the parking tooth, also cause the axis of parking tooth broach spline like this and the axis of excircle rectangle tooth not be in coaxially, lead to the parking tooth to be unqualified easily.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a synchronous extrusion molding device for simultaneously processing the excircle rectangular teeth of the parking teeth and the tooth profile of the parking teeth and the internal splines by cold extrusion.

The technical scheme adopted by the utility model is as follows:

the synchronous extrusion forming device for the parking tooth profile and the internal spline comprises an upper die and a lower die, wherein the bottom of the upper die is of an annular structure, a circle of rectangular teeth are arranged on the periphery of the bottom of the upper die, a male die is arranged at the center of the lower die, and the male die corresponds to an inner concave cavity formed in the bottom of the upper die; the periphery of the male die is provided with a circle of external splines, the side wall of the lower die inner ring is provided with a circle of rectangular tooth grooves corresponding to the rectangular teeth, the bottom of the upper die, the rectangular tooth grooves and the external splines are combined to form a cavity for processing an annular blank, the lubricated annular blank is placed in the cavity when the die is used, the rectangular teeth primarily processed by the annular blank are placed in the rectangular tooth grooves, inner holes of the rectangular tooth grooves are correspondingly placed on the male die, the upper die is used for extruding the rectangular tooth grooves and the annular blank in the cavity, and finishing extrusion of the parking tooth rectangular teeth and cold extrusion forming of the internal splines are completed simultaneously.

According to the scheme, the cold extrusion forming of the rectangular teeth and the internal splines of the annular blank is realized through the cold extrusion die, compared with two processes of processing the rectangular teeth on the excircle of the parking tooth through the hobbing and then pulling the splines on the inner hole of the parking tooth in the parking tooth extrusion forming process in the prior art, the scheme only needs one process, and the processing of the rectangular teeth and the internal splines of the parking tooth can be finished simultaneously; simultaneously, still need repeatedly carry out the centre gripping location to cyclic annular blank among the prior art, and this scheme cooperates with the terrace die through the extrusion cavity in the lower mould, once only accomplishes the location to cyclic annular blank, just so can guarantee that the axis of parking tooth hole is in same axis with the axis of cyclic annular blank when the extrusion, guarantees that the axiality is unanimous.

Furthermore, the male die is inverted T-shaped, a positioning block is arranged at the top of the male die, and the diameter of the positioning block is smaller than that of the male die.

By the design, when the annular blank is placed on the male die, the annular blank is positioned by matching the positioning block with the extrusion cavity; meanwhile, the diameter of the positioning block is smaller than that of the male die, so that the annular blank moves downwards along the male die when being pressed, and an inner hole of the annular blank is machined to form an inner spline.

Further, the bottom of the lower die is provided with a base, the base is provided with a through hole, a push rod which moves up and down along the length direction of the through hole and penetrates through the male die is arranged in the through hole, the top of the push rod is provided with a plurality of back pressure blocks which are abutted against the bottom of the annular blank, and after the annular blank is pressed, the back pressure blocks extrude the lower surface of the annular blank to form a base surface of the end surface of the parking tooth.

This scheme is through applying ascending holding power at the ejector pin, realizes the base face that forms parking tooth terminal surface to annular blank extrusion through the backpressure piece at ejector pin top, like this, just can guarantee that the base face of rectangle tooth is unanimous with the base face of internal spline, simultaneously, also avoids when last mould extrusion, leads to annular blank compression deformation.

Furthermore, the lower surface of the upper die is step-shaped, the upper surface of the back pressure block is reverse step-shaped, and when the device is used, the lower surface of the upper die is matched with the upper surface of the back pressure block to extrude the end face of the parking tooth.

When this scheme was passed through the mould and is pushed annular blank downwards, annular blank lower surface and backpressure piece offset, annular blank upper surface offsets with last mould lower surface, along with last mould to the effort that annular blank was applyed for annular blank longitudinal section is the step form.

Further, still include roof and push rod, the roof is discoid, roof bottom and push rod fixed connection, the top equipartition have a plurality of knock-outs poles that pass the terrace die, knock-outs pole and back pressure piece one-to-one, just knock-outs pole and back pressure piece fixed connection.

According to the scheme, acting force is applied to the push rod, so that two functions are realized, firstly, when the upper die applies downward thrust to the annular blank in the extrusion cavity, upward supporting force to the annular blank is applied through the push rod, and under the action of the two forces, the extrusion stability of the annular blank can be ensured, and the annular blank is prevented from deforming; secondly, when the upper die does not apply downward thrust to the annular blank in the extrusion cavity, the push rod applies upward thrust to the annular blank, so that the annular blank formed by cold extrusion is separated from the extrusion cavity, and the annular blank is conveniently taken out.

Further, a base plate is arranged between the lower die and the base, and the ejector rod penetrates through the cushion block to be fixedly connected with the male die and the back pressure block. By the design, the stable environment of the whole cold extrusion die is ensured through the backing plate, and the balance of the stress environment of the annular blank is ensured.

Compared with the prior art, the utility model has the following advantages:

1. this scheme adopts the cold extruded method to forge out the external circle rectangle tooth of parking tooth and the internal spline of parking tooth hole simultaneously, and is high than hot forging size precision, and the oxidation is few, and the inherent tissue of metal is good, and the crystalline grain is more refined, avoids bad tissue such as coarse grain, mixed crystal, simultaneously, because the external circle rectangle tooth of parking tooth and internal spline once only fix a position in cold extrusion die, can improve axiality between them, also improve the straightness that hangs down of external circle rectangle tooth terminal surface and internal spline flank of tooth terminal surface simultaneously.

2. The outer circle rectangular teeth of the parking teeth and the inner splines of the inner holes of the parking teeth are synchronously performed, so that the manufacturing time can be shortened, the rejection rate of parts is reduced, and the manufacturing cost is reduced.

3. According to the scheme, the tooth shapes of the excircle rectangular tooth and the internal spline are subjected to cold extrusion, the deformation amount of the tooth shape is small, so that the tooth shape precision is more easily achieved, and the size is stable; the die life is very high.

4. This scheme is through carrying out the shot blasting back for the first time to the raw materials material section, and lubricated back carries out cold extrusion to cyclic annular blank, obtains the excircle rectangle tooth and the hole internal spline of parking tooth simultaneously, and follow-up carries out the finish turning to the blank again, and the whole manufacturing procedure that shortens carries out cold extrusion simultaneously, can effectively eliminate the inside stress of material section, is showing each item mechanical properties index that improves cold extrusion shaping back gear.

Drawings

FIG. 1 is a schematic structural view of a synchronous extrusion molding device for parking tooth profiles and internal splines according to the present invention.

In the figure: the die comprises an upper die 1, a lower die 2, an extrusion chamber 3, rectangular teeth 4, a male die 5, an external spline 6, a base 7, a through hole 8, a back pressing block 9, an ejector rod 10, a top plate 11, a push rod 12, a backing plate 13 and an annular blank 14.

Detailed Description

The utility model will be described in connection with the following figures and examples.

In this embodiment: referring to fig. 1, the synchronous extrusion molding device for the parking tooth profile and the internal spline comprises an upper die 1 and a lower die 2, wherein the bottom of the upper die 1 is of an annular structure, a circle of rectangular teeth 4 is arranged on the periphery of the bottom of the upper die 1, a male die 5 is arranged at the center of the lower die 2, a circle of external splines 6 is arranged on the periphery of the male die 5, a circle of rectangular tooth grooves corresponding to the rectangular teeth 4 are arranged on the side wall of the inner ring of the lower die 2, the bottom of the upper die 1, the rectangular tooth grooves and the external splines 6 are combined to form a cavity 3 for processing an annular blank 14, when in use, the lubricated annular blank 14 is placed in the cavity 3, the rectangular teeth which are primarily processed by the annular blank are placed in the rectangular tooth grooves, the inner hole is correspondingly arranged on the male die 5, the upper die 1 is used for extruding the rectangular tooth socket and the annular blank 14 in the cavity 3, finishing extrusion of the parking gear rectangular teeth and cold extrusion molding of the internal spline are completed simultaneously, and the extrusion process is a continuous extrusion mode.

According to the scheme, the cold extrusion forming of the rectangular teeth 4 and the internal splines of the annular blank 14 is simultaneously realized through the cold extrusion die, compared with two processes of machining the rectangular teeth 4 on the excircle of the parking tooth through hobbing and then pulling the splines on the inner hole of the parking tooth in the parking tooth extrusion forming process in the prior art, the scheme only needs one process, and the machining of the rectangular teeth 4 and the internal splines of the parking tooth can be simultaneously completed; meanwhile, in the prior art, the annular blank 14 needs to be clamped and positioned repeatedly, the scheme is that the extrusion cavity 3 in the lower die 2 is matched with the male die 5, and the annular blank 14 is positioned at one time, so that the central axis of the inner hole of the parking tooth and the central axis of the annular blank 14 are on the same axis when the annular blank 14 is extruded, and the coaxiality is consistent.

Preferably, the male die 5 is in an inverted T shape, a positioning block is arranged at the top of the male die 5, and the diameter of the positioning block is smaller than that of the male die 5. By the design, when the annular blank 14 is placed on the male die 5, the annular blank 14 is positioned by matching the positioning block with the extrusion chamber 3; meanwhile, the diameter of the positioning block is smaller than that of the male die 5, so that the annular blank 14 moves downwards along the male die 5 when being pressed, and an inner hole of the annular blank 14 is machined to form an inner spline.

Preferably, the bottom of the lower die 2 is provided with a base 7, the base 7 is provided with a through hole 8, a mandril which moves up and down along the length direction of the mandril and penetrates through the convex die 5 is arranged in the through hole 8, the top of the mandril is provided with a plurality of back pressure blocks 9 which are abutted against the bottom of the annular blank 14, and after the annular blank 14 is pressed, the back pressure blocks 9 extrude the lower surface of the annular blank 14 to form a base surface of the end surface of the parking tooth.

This scheme is through applying ascending holding power at the ejector pin, realizes forming the base plane of parking tooth terminal surface to the extrusion of cyclic annular blank 14 through the backpressure piece 9 at ejector pin top, like this, just can guarantee that the base plane of rectangle tooth 4 is unanimous with the base plane of internal spline, simultaneously, also avoids when last mould 1 extrudees, leads to cyclic annular blank 14 pressurized deformation.

Preferably, the lower surface of the upper die 1 is step-shaped, the upper surface of the back pressure block 9 is reverse step-shaped, and when the upper die is used, the lower surface of the upper die 1 is matched with the upper surface of the back pressure block 9 to extrude the end face of the parking tooth.

According to the scheme, when the upper die 1 extrudes the annular blank 14 downwards, the lower surface of the annular blank 14 is abutted against the back pressure block 9, the upper surface of the annular blank 14 is abutted against the lower surface of the upper die 1, and the longitudinal section of the annular blank 14 is in a step shape along with the acting force applied to the annular blank 14 by the upper die 1.

Preferably, the punch further comprises a top plate 11 and a push rod 12, wherein the top plate 11 is disc-shaped, the bottom of the top plate 11 is fixedly connected with the push rod 12, a plurality of ejector rods 10 penetrating through the male die 5 are uniformly distributed at the top of the top plate, the ejector rods 10 correspond to the back pressure blocks 9 one by one, and the ejector rods 10 are fixedly connected with the back pressure blocks 9.

According to the scheme, acting force is applied to the push rod 12, two functions are achieved, firstly, when the upper die 1 applies downward pushing force to the annular blank 14 in the extrusion cavity 3, upward supporting force to the annular blank 14 is applied through the push rod 12, and under the action of the two forces, the extrusion stability of the annular blank 14 can be ensured, and the annular blank 14 is prevented from deforming; secondly, when the upper die 1 does not apply downward thrust to the annular blank 14 in the extrusion chamber 3, the push rod 12 applies upward thrust to the annular blank 14, so that the annular blank 14 formed by cold extrusion is separated from the extrusion chamber 3, and the annular blank 14 is convenient to take out.

Preferably, a backing plate 13 is arranged between the lower die 2 and the base 7, and the ejector rod 10 penetrates through the backing plate to be fixedly connected with the punch 5 and the back pressure block 9. By the design, the stable environment of the whole cold extrusion die is ensured by the backing plate 13, and the balance of the stress environment of the annular blank 14 is ensured.

The device is applied to the parking gear machining and forming process and comprises the processes of blanking, forging, normalizing, rough turning, first shot blasting, lubricating, cold extruding, finish turning, carburizing and quenching and second shot blasting, wherein in the blanking process, raw material blanks are sawn to a specified size according to design requirements, in the forging process, the sawn blanks are heated to 950 +/-20 ℃ by using power frequency heating equipment, upsetting and inner hole punching and extruding are completed on forging equipment to form cup-shaped blanks, and the blanks after forging are placed in a blank heat-insulating barrel to store forging waste heat.

In the normalizing procedure, the hot forging stock is placed in a shaft furnace, and during heating, spheroidizing annealing treatment of the forging stock is completed under the protective atmosphere by pre-vacuumizing, introducing nitrogen and simultaneously dropwise adding methanol to remove oxygen, so that the hardness of the stock is reduced to less than or equal to 140 HB.

After the normalizing process is finished, roughly turning the cup-shaped blank, and punching on an open press to form an annular blank 14; and performing primary shot blasting, performing shot blasting on the annular blank 14 to remove oxide skin, turning the inner hole and the end face of the annular blank 14, then performing high-molecular lubricant infiltration treatment, and performing air drying for extrusion.

After the extrusion is finished and the hot front machine is machined, in the carburizing and quenching treatment, the carbon potential is controlled to be 1% in the strong carburizing stage and 0.8% in the diffusion stage, the surface hardness, the core hardness, the carburized layer depth and the grain size of the quenched part meet the technical requirements, and the tooth surface directly meets the design requirements after the second shot blasting.

1. This scheme adopts the cold extruded method to forge out the internal spline in the excircle rectangle tooth 4 and the parking tooth hole of parking tooth simultaneously, and is high than hot forging size precision, and the oxidation is few, and the inherent tissue of metal is good, and the crystalline grain is more refined, avoids coarse grain, thoughtlessly brilliant etc. bad tissue, simultaneously, because the excircle rectangle tooth 4 and the internal spline of parking tooth once only fix a position in cold extrusion die, can improve axiality between them, also improve the straightness that hangs down of 4 terminal surfaces of excircle rectangle tooth and internal spline flank of tooth terminal surfaces simultaneously.

2. The excircle rectangle tooth 4 and the internal spline of parking tooth hole of parking tooth through this scheme go on in step, like this, can shorten the manufacturing time, reduce the rejection rate of part, reduce manufacturing cost.

3. According to the scheme, the tooth forms of the excircle rectangular tooth 4 and the internal spline are subjected to cold extrusion, the deformation amount of the tooth forms is small, so that the tooth form precision is more easily achieved, and the size is stable; the die life is very high.

4. This scheme is through carrying out the shot blasting back for the first time to the raw materials material section, and lubricated back carries out cold extrusion to cyclic annular blank 14, obtains the excircle rectangle tooth 4 and the hole internal spline of parking tooth simultaneously, and follow-up carries out the finish turning to the blank again, and the whole manufacturing procedure that shortens carries out cold extrusion simultaneously, can effectively eliminate the inside stress of material section, is showing each item mechanical properties index that improves cold extrusion shaping rear gear.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and those skilled in the art should understand that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all that should be covered by the claims of the present invention.

Claims (6)

1. The synchronous extrusion forming device for the parking tooth profile and the internal spline is characterized by comprising an upper die (1) and a lower die (2), wherein the bottom of the upper die (1) is of an annular structure, a circle of rectangular teeth (4) are arranged on the periphery of the bottom of the upper die (1), a male die (5) is arranged at the center of the lower die (2), and the male die (5) corresponds to an inner concave cavity formed at the bottom of the upper die (1); the side of the male die (5) is provided with a circle of external splines (6), the side wall of the inner ring of the lower die (2) is provided with a circle of rectangular tooth grooves corresponding to the rectangular teeth (4), and the bottom of the upper die (1), the rectangular tooth grooves and the external splines (6) are combined to form a cavity (3) for processing an annular blank (14).

2. The synchronous extrusion molding device for the parking tooth shapes and the internal splines according to claim 1, wherein the male die (5) is in an inverted T shape, a positioning block is arranged at the top of the male die (5), and the diameter of the positioning block is smaller than that of the male die (5).

3. The synchronous extrusion molding device for the parking teeth and the internal splines as claimed in claim 1, wherein a base (7) is arranged at the bottom of the lower die (2), the base (7) is provided with a through hole (8), an ejector rod which moves up and down along the length direction of the through hole (8) and penetrates through the male die (5) is arranged in the through hole, the top of the ejector rod is provided with a plurality of back pressure blocks (9) which are abutted against the bottom of the annular blank (14), and after the annular blank (14) is pressed, the back pressure blocks (9) extrude the lower surface of the annular blank (14) to form a base surface of the end surface of the parking teeth.

4. The synchronous extrusion molding device for the parking teeth and the internal splines as claimed in claim 1, wherein the lower surface of the upper die (1) is step-shaped, the upper surface of the back pressing block (9) is reverse step-shaped, and the lower surface of the upper die (1) and the upper surface of the back pressing block (9) are matched to extrude the end face of the parking teeth.

5. The synchronous extrusion molding device for the parking tooth shape and the internal spline according to claim 1, further comprising a top plate (11) and a push rod (12), wherein the top plate (11) is disc-shaped, the bottom of the top plate (11) is fixedly connected with the push rod (12), a plurality of ejector rods (10) penetrating through the male die (5) are uniformly distributed on the top of the top plate, the ejector rods (10) correspond to the back pressure blocks (9) one by one, and the ejector rods (10) are fixedly connected with the back pressure blocks (9).

6. The synchronous extrusion molding device for the tooth profile and the internal spline of the parking gear according to claim 5, wherein a cushion plate (13) is arranged between the lower die (2) and the base (7), and the ejector rod (10) penetrates through the cushion block to be fixedly connected with the male die (5) and the back pressing block (9).

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