Three-pin type universal joint cold finishing die

Abstract

The utility model discloses a three-pin type universal joint cold finishing die which comprises an upper die and a lower die which is coaxially installed and located below the upper die, and further comprises a discharging mechanism and a discharging mechanism which are installed on the lower die. After the upper die carries out the extrusion process on a forge piece placed in the lower die, the upper die unloads the forge piece arranged on the upper die in a sleeving mode through the unloading mechanism when returning and resetting are carried out on the upper die, the unloaded forge piece is sent out of the lower die through the discharging mechanism, and a universal joint obtained through machining of the die reduces metal deformation resistance, is high in precision and good in surface quality and has good machining performance. And the procedure of machining the cup-shaped part is omitted, so that the production efficiency is greatly improved.

Description

Technical Field

[0001] The utility model relates to the field of automobile universal joints, in particular to a three-pin universal joint cold finishing die. Background Art

[0002] In the automobile transmission system and other systems, in order to achieve power transmission between two rotating shafts whose axes do not overlap, a universal joint transmission device must be used. The universal joint transmission device is generally composed of a universal joint and a drive shaft, and sometimes also includes an intermediate support. The universal joint is the "joint" part of the universal joint transmission device in the automobile transmission system, which allows the angle between the connected parts to change within a certain range and allows a certain range of relative telescopic movement between the connected parts. The universal joint, also known as the sliding sleeve, is a component of the automobile constant velocity universal joint drive device. The inner cavity of the automobile universal joint is evenly distributed in the inner hole by the arc surface, and a ball track is naturally formed in the inner hole. Since the constant velocity universal joint transmits heavy driving torque, it is subjected to heavy loads, has high transmission accuracy, is in great demand, and is also a safety part, so its main parts are all made of precision forgings.

[0003] During the assembly process of automobile universal joints, the tripod is inserted into the inner cavity of the universal joint to slide, so as to prevent interference with the bottom of the inner cavity during the sliding process. Therefore, the consistency of the shape of the bottom of the universal joint cavity and the R angle must be ensured during the forging process. At present, domestic and foreign manufacturers have adopted the technology of inner cavity precision forging to form blanks, which can not only meet the precision requirements, but also reduce the manufacturing cost and cycle, and also conform to the development trend of the world's manufacturing industry.

[0004] For example, Chinese patent CN 108856620 A discloses a cold finishing die for the outer star wheel of a universal joint of an automobile. The punch comprises an upper die plate, a fixing assembly, a column and a punch. The column is fixed on the upper die plate through the fixing assembly. The column is a conical column, the top of which is conically contracted, and six assembly grooves are evenly distributed on the wall. The punch is composed of six die halves with convex bodies. The overall appearance structure of the punch composed of the die halves is a cylindrical structure with a central hole and six convex bodies are evenly distributed on the cylindrical wall. Two adjacent convex bodies are arranged axially symmetrically. The convex bodies match the outer inclined ball track, and the central hole cavity matches the conical contraction surface of the column. The die halves are also provided with convex ribs that match the assembly grooves on the column. The punch is fixed on the column through the punch fixing assembly. The cold finishing die adopts a warm and cold combined forging method to replace cutting processing, which has high production efficiency, low cost, short cycle, and metal streamlines are not cut off. It has high strength and impact resistance, saves raw materials, and can meet the production requirements of supporting automobile parts. When this technical solution is actually applied, it will cause problems such as decarburization and thick oxide scale, which will reduce the surface quality of the product.

[0005] Another example is a telescopic ball cage constant velocity universal joint disclosed in Chinese patent CN201410129701.5, which includes an outer star wheel with an inner cavity and an inner star wheel located in the inner cavity, a ball cage is arranged between the outer star wheel and the inner star wheel, a plurality of outer ball tracks are opened on the inner surface of the outer star wheel, a plurality of inner ball tracks arranged opposite to the outer ball tracks are opened on the outer surface of the inner star wheel, a plurality of ball cage windows connected to the outer ball tracks and the inner ball tracks are opened on the circumferential surface of the ball cage, a rolling body is arranged in each ball cage window, the inner and outer ends of the rolling body are respectively located in the inner ball track and the outer ball track, and the outer ball track includes three uniformly distributed along the circumference of the outer star wheel. The outer oblique ballway is provided with an outer straight ballway between two adjacent outer oblique ballways, the center line of the outer oblique ballway and the axis of the outer star wheel form an acute angle α, the center line of the outer straight ballway is parallel to the axis of the outer star wheel, the inner ballway includes an inner oblique ballway and an inner straight ballway, the inner oblique ballway and the outer oblique ballway are arranged in mirror symmetry, and the inner straight ballway and the outer straight ballway are arranged in mirror symmetry; the center lines of the three outer oblique ballways and the center lines of the three inner oblique ballways intersect to obtain three intersection points, an angle bisector is determined by these three intersection points, and the angle bisector bisects the angle γ formed by the axis of the outer star wheel and the axis of the inner star wheel, and the centers of multiple rolling bodies are all located in the angle bisector. The metal streamline is cut off, the internal structure of the material is loose and the density is not good, the mechanical properties are poor, the production efficiency is low, the material utilization rate is low, the production cycle is long, the processing cost is high, and it is difficult to meet the quality requirements of automobile parts. However, the universal joint has a large processing allowance in actual operation, a long processing cycle, and low efficiency. Summary of the invention

[0006] Purpose of the utility model: In order to solve the shortcomings of the existing technology, the utility model provides a three-pin universal joint cold finishing mold, which can avoid the problems of decarburization and thick oxide scale in the produced universal joint, improve the surface quality of the universal joint, reduce machining allowance, shorten the processing cycle and increase efficiency.

[0007] Technical solution: In order to achieve the above purpose, the utility model discloses a three-pin universal joint cold finishing die, which comprises: an upper die, a lower die coaxially installed and located below the upper die, and a discharge mechanism and a discharging mechanism installed on the lower die;

[0008] After the upper die completes the extrusion process on the forging placed in the lower die, the upper die unloads the forging sleeved on the upper die through the unloading mechanism when returning to the original position, and the unloaded forging is sent out of the lower die through the discharging mechanism.

[0009] As a further preferred embodiment of the present invention, the upper die comprises: an upper die plate connected to a press slide, a cushion block A inserted on the upper die plate, an upper punch located below the cushion block A, and an upper punch sleeve sleeved on the outer side of the upper punch, wherein the upper punch sleeve is fixedly connected to the upper die barrel through a positioning pin A, and an upper die pressing cover sleeved on the radial outer side of the upper die barrel fastens the upper die barrel, the upper punch sleeve and the upper punch;

[0010] The upper die barrel fixes the upper punch, the upper punch cover, the upper die pressing cover and the cushion block A which are fastened together on the upper die plate.

[0011] As a further preferred embodiment of the present invention, a plane provided on the radial outer side of the upper punch abuts against a plane on the upper punch sleeve, so that the upper punch cannot rotate arbitrarily in the upper die barrel.

[0012] As a further preferred embodiment of the present invention, the lower die comprises: a lower die plate connected to a machine tool worktable, a pad D passing through the lower die plate, a pad C, a pad B and a cold finishing die radially outside of which are located above and adjacent to the pad D, a lower die cover radially outside the cold finishing die to fix the cold finishing die in the lower die barrel, and the lower die barrel is vertically mounted on the lower die plate by screws;

[0013] The cushion block B is radially provided with a plurality of discharge holes for placing the discharge mechanism, and the cushion block C is radially provided with a discharge hole for placing the discharge mechanism.

[0014] As a further preferred embodiment of the utility model, the unloading mechanism includes: a unloading rod, a spring, a spring pad, a headless bolt and a unloading rod cover plate located in the unloading hole, the two ends of the spring are respectively provided with a unloading rod and a spring pad, the other end of the spring pad is provided with a headless bolt that abuts against the spring pad, and a unloading rod cover plate is provided above the unloading rod, and the unloading rod cover plate is fixed to the pad B by screws.

[0015] As a further preferred embodiment of the present invention, the plane on the discharge rod abuts against the plane provided on the discharge rod cover plate, and the discharge rod is located on the side close to the axis.

[0016] As a further preferred embodiment of the present invention, the discharging mechanism includes a cylinder, an ejection block and a cylinder connecting block, one end of the ejection block is inserted into the discharging hole on the cushion block C, the other end of the ejection block is fastened to the cylinder, and the cylinder is fixed to the radial surface of the lower mold barrel through the cylinder connecting block.

[0017] As a further preferred embodiment of the present invention, the cylinder is connected to a solenoid valve controlled by a controller PLC.

[0018] As a further preference of the utility model, a slide for taking materials is provided on one side of the discharging mechanism. When the forging falls onto the slide, the controller PLC sends a command to the solenoid valve to move the cylinder forward to drive the ejection block to push the forging out of the slide, and finally the forging is clamped into the material frame with pliers.

[0019] Beneficial effects: Compared with the prior art, the three-pin universal joint cold finishing mold described in the utility model avoids the generation of more oxide scale and decarburization and reduces the metal deformation resistance. The universal joint obtained by cold finishing mold processing has high precision and good surface quality, eliminates the process of machining the cup-shaped part, and greatly improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a partial cross-sectional schematic diagram of the utility model when not extruded;

[0021] Figure 2 It is a partial cross-sectional schematic diagram of the utility model during extrusion;

[0022] Figure 3 Schematic diagram of the structural position of the slide. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] like Figure 1 , Figure 2 As shown, the utility model describes a three-pin universal joint cold finishing mold, which includes: an upper mold composed of an upper punch 11, an upper punch sleeve 12, an upper mold cover 13, an upper mold barrel 14, an upper mold plate 15, a pad A16 and a locating pin A17; a lower mold composed of a cold finishing die 21, a lower mold cover 22, a pad B23, a pad C24, a pad D25, a lower mold plate 26 and a lower mold barrel 28; a discharge mechanism composed of a discharge rod 31, a spring 32, a spring pad 33, a headless bolt 34 and a discharge rod cover plate 35; and a discharge mechanism composed of a cylinder 41, a push-out block 42 and a cylinder connecting block 43.

[0025] The upper template 15 is connected to the press slider, the pad A16 is passed through the upper template 15, the upper punch 11 is located below the pad A16, the upper punch sleeve 12 is sleeved on the outside of the upper punch 11, the upper punch sleeve 12 is fixedly connected to the upper die barrel 14 through the locating pin A17, the upper die cover 13 sleeved on the radial outside of the upper die barrel 14 fastens the upper die barrel 14, the upper punch sleeve 12 and the upper punch 11, and the upper die barrel 14 fixes the upper punch 11, the upper punch sleeve 12, the upper die cover 13 and the pad A16 fastened together on the upper template 15.

[0026] The lower template 26 is connected to the worktable of the machine tool, the pad D25 is penetrated on the lower template 26, the lower die barrel 28 is sleeved on the outer sides of the pad C24, the pad B23 and the cold finishing die 21 which are located above the pad D25 and are close to each other in sequence, the locating pin C27 is fixed in the locating groove on the side of the pad B23, the whole is loaded into the lower die barrel 28, the lower die pressing cover 22 is sleeved on the radial outer side of the cold finishing die 21 to fix the cold finishing die 21 in the lower die barrel 28, the lower die barrel 28 is vertically installed on the lower template 26 by screws, the locating pin B29 is fixed in the outer circle locating groove of the cold finishing die 21 by bolts, the cold finishing die 21 is loaded into the lower die barrel 28, and the cold finishing die 21 is fixed in the lower die barrel 28 by the lower die pressing cover 22.

[0027] A discharge rod 31 and a spring pad 33 are respectively provided at both ends of the spring 32 located in the discharge hole. A headless bolt 34 is provided at the other end of the spring pad 33, which abuts against the spring pad 33. A discharge rod cover plate 35 is provided above the discharge rod 31. The discharge rod cover plate 35 is fixed to the pad B23 by screws, and the plane on the discharge rod 31 close to the axis side abuts against the plane provided on the discharge rod cover plate 35.

[0028] One end of the ejection block 42 is inserted into the discharge hole on the cushion block C24 , and the other end of the ejection block 42 is fastened to the cylinder 41 . The cylinder 41 is fixed to the radial surface of the lower die barrel 28 through a cylinder connecting block 43 .

[0029] Example

[0030] Step 1: Clamp the forging into the cold finishing die 21, and the upper punch 11 connected to the press slide moves downward into the inner hole of the forging. The upper punch 11 pushes the forging downward to start thinning and stretching. The material flows upward along the gap between the cold finishing die 21 and the upper punch 11 to form a cup portion.

[0031] Step 2: When the upper punch 11 continues to push the forging downward, the forging starts to compress the spring 32 on the rear side of the discharge rod 31 when it hits three evenly distributed discharge rods 31 in the circumferential direction, until the upper punch 11 pushes the upper end surface of the forging through the discharge rod 31. The three evenly distributed discharge rods 31 in the circumferential direction are reset to 2 / 3 of the wall thickness of the forging under the action of the spring force, and the upper punch 11 moves upward, and the discharge rod 31 removes the forging from the upper punch 11.

[0032] Step three, a cylinder 41 is installed on the front side of the slide, and the push-out block 41 is connected to the cylinder 41. When the forging falls onto the slide, the controller PLC sends a command to the solenoid valve to make the cylinder 41 move forward to drive the push-out block 42 to push the forging out of the slide. Finally, the forging is clamped into the material frame with pliers. The controller PLC sends a command to the solenoid valve to make the cylinder 41 move backward to reset the push-out block 42 and proceed to the next cycle.

[0033] Because the three-pin universal joint is a special-shaped part, the upper punch 11 corresponds to the position of the cold finishing die 21 during cold finishing. The upper punch 11 is limited by the outer circle plane and the inner hole plane of the upper punch sleeve 12, and the upper punch sleeve 12 and the upper die barrel 14 are limited by the positioning pin A17, so that the upper punch 11 cannot rotate arbitrarily in the upper die barrel 14.

[0034] The cold finishing die 21 and the lower die barrel 28 are limited by the positioning pin B29, thus limiting the relative position relationship between the upper punch 11 and the cold finishing die 21. Since there are three unloading rods 31 in the pad B23, and the unloading rods 31 are related to the unloading position of the forging, a positioning groove is provided on the outer circle of the pad B23, which cooperates with the positioning groove of the inner hole of the lower die barrel 28 through the positioning pin C27, so that the pad B23 cannot rotate in the lower die barrel 28.

[0035] The head of the discharge rod 31 is provided with an angle of 60° to 80° to play a guiding role. In order to allow the forging to pass through the discharge rod 31 smoothly, a plane is provided on the outer circle of the discharge rod 31 to prevent the discharge rod 31 from rotating freely, so that the angle of the head of the discharge rod 31 always remains in the same direction.

[0036] The above implementation is only to illustrate the technical concept and features of the utility model, and its purpose is to enable technicians familiar with the technical field to understand the content of the utility model and implement it accordingly, and it cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A three-pin universal joint cold finishing die, comprising: The upper die and the lower die which are coaxially mounted and located below the upper die are characterized in that: the lower die also includes a discharge mechanism and a discharge mechanism mounted on the lower die; After the upper die completes the extrusion process on the forging placed in the lower die, the upper die unloads the forging sleeved on the upper die through the unloading mechanism when returning to the original position, and the unloaded forging is sent out of the lower die through the discharging mechanism.

2. A three-pin universal joint cold finishing die according to claim 1, characterized in that: The upper die comprises: an upper die plate (15) connected to a slide block of a press machine, a cushion block A (16) inserted into the upper die plate (15), an upper punch (11) located below the cushion block A (16), and an upper punch sleeve (12) sleeved on the outer side of the upper punch (11); the upper punch sleeve (12) is fixedly connected to the upper die barrel (14) via a positioning pin A (17); an upper die pressing cover (13) sleeved on the radial outer side of the upper die barrel (14) fastens the upper die barrel (14), the upper punch sleeve (12) and the upper punch (11); The upper die barrel (14) fixes the upper punch (11), the upper punch sleeve (12), the upper die cover (13) and the cushion block A (16) which are fastened together on the upper die plate (15).

3. A three-pin universal joint cold finishing die according to claim 2, characterized in that: The plane provided on the radial outer side of the upper punch (11) abuts against the plane on the upper punch sleeve (12).

4. A three-pin universal joint cold finishing die according to claim 1, characterized in that: The lower die comprises: a lower die plate (26) connected to a machine tool worktable, a pad D (25) inserted on the lower die plate (26), a pad C (24) and a pad B (23) located above and adjacent to the pad D (25) in sequence, and a lower die barrel (28) sleeved on the radial outer side of the cold finishing die (21), a lower die cover (22) sleeved on the radial outer side of the cold finishing die (21) to fix the cold finishing die (21) in the lower die barrel (28), and the lower die barrel (28) is vertically mounted on the lower die plate (26) by screws; The pad B (23) is provided with a discharge hole for accommodating a discharge mechanism in its inner radial direction, and the pad C (24) is provided with a discharge hole for accommodating a discharge mechanism in its inner radial direction.

5. A cold finishing die for a three-pin universal joint according to claim 1 or 4, characterized in that: The unloading mechanism comprises: a unloading rod (31) located in the unloading hole, a spring (32), a spring pad (33), a headless bolt (34) and a unloading rod cover plate (35), wherein the two ends of the spring (32) are respectively provided with an unloading rod (31) and a spring pad (33), the other end of the spring pad (33) is provided with a headless bolt (34) which abuts against the spring pad (33), and a unloading rod cover plate (35) is provided above the unloading rod (31), and the unloading rod cover plate (35) is fixed on the pad B (23) by screws.

6. A three-pin universal joint cold finishing die according to claim 5, characterized in that: The plane on the discharge rod (31) abuts against the plane provided on the discharge rod cover plate (35).

7. A three-pin universal joint cold finishing die according to claim 5, characterized in that: The discharge rod (31) is located on a side close to the axis.

8. A cold finishing die for a three-pin universal joint according to claim 1 or 4, characterized in that: The discharge mechanism comprises a cylinder (41), a push-out block (42) and a cylinder connecting block (43); one end of the push-out block (42) is inserted into a discharge hole on a cushion block C (24); the other end of the push-out block (42) is fastened to the cylinder (41); and the cylinder (41) is fixed to a radial surface of the lower die barrel (28) via the cylinder connecting block (43).

9. A cold finishing die for a three-pin universal joint according to claim 8, characterized in that: The cylinder (41) is connected to a solenoid valve controlled by a PLC.

10. A three-pin universal joint cold finishing die according to claim 1, characterized in that: One side of the discharging mechanism is provided with a slideway for taking materials.

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