JPH03165947A - Forging die for working gear - Google Patents

Abstract

PURPOSE:To form spline teeth to the desired shaped with a teeth punch after preworking with a round punch by advancing the round punch and the teeth punch to one teeth die in order. CONSTITUTION:Under mounting a raw material for a gear on a die 14 in a lower anvil 30, an upper anvil 32 is descended and a first mandrel 35 and the round punch are advanced into the die 14. Then, the raw material is preworked to spread the teeth part of the spline into teeth part 17 in the die 14. Successively, while mounting the gear raw material on the die 14 at it is, by horizontally shifting the slider 33, a second mandrel 40 and the teeth punch 41 are positioned to center of the die 14 in the lower anvil 30. Then, by descending the upper anvil 32, the spreading part H is formed into shape of the teeth part 17 in the die 14 with the teeth punch 41. Further, back face of the gear 1 is made to flat with the teeth punch 41 and machining work of the gear 41 in the sequential process is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applications!l!j,) The present invention relates to a gear processing forging die for forging gears such as automobile transmission gears.

(Prior Art) Gears used in automobile transmissions have shapes as shown in FIGS. 3 and 4. This gear 1 has an annular shape as a whole, has a shaft hole 2, and has a thin wall portion 3 formed on the tip end side in the axial direction. The rear end portion of this is thick, and spline teeth 4 are provided at predetermined intervals on its outer periphery. This spline tooth 4
On the end face of one end, that is, the front end face, in order to facilitate engagement with the internal spline of the mating sleeve when this gear is assembled into the 1-transmission,
A chamfer portion 5 having a triangular cross section is formed. Reference numeral 6 indicates the ridgeline of the chamfer portion 5.

In order to form such a gear by forging, a forging die shown in Japanese Patent Application Laid-Open No. 60-213333 has been developed. This forging die is shown in FIG. 5, and a die base 11 is fixed to a bolster (not shown), and this die base 11 has a shaft hole 12. A die 14 having a die hole 13 aligned with the shaft hole 12 is fixed on the die base 11. This die 14 is formed with a tapered surface 15 that forms the outer peripheral surface of the thin part 3 of the gear 1, and a shoulder part 16 that forms the front end surface of the thick part, and these form the shape of the gear 1. ing. Furthermore, this die 14 is formed with a tooth portion 17 for forming the spline tooth 4.
The lower end of 7 is a stepped portion 18 that is positioned offset from the shoulder portion 16 in one direction.

A cushion pad 20 is mounted in a shaft hole 12 formed in the die base 11 so as to be vertically movable, and this vertical movement is performed by a cushion pin 21. Furthermore, a cylindrical lifter sleeve 22 is placed on the cushion pad 20. This lifter sleeve 22
is for forming the end face on the tip side of gear 1,
It is configured to move up and down via the cushion pad 20 by the cushion pin 21.

The lower mold made of the above-mentioned members includes a mandrel 2
5 and a punch 26 enters. The mandrel 25 also contacts the inner circumferential surface of the gear 1 and the inner circumferential surface of the lifter sleeve 22. Further, the punch 26 has a circumferential surface whose outer diameter is slightly smaller than the inner circumference of the cutting edge of the tooth portion 17 formed on the die 14, and is a so-called round die.

To form the gear 1 using such a conventional forging die, the material of the gear 1 is loaded into the lower die, and then the upper die is lowered to enter the lower die. Then, the gear 1 is formed into the shape shown in FIG. In the forging die shown in FIG. 5, by forming a stepped portion 18 which is shifted toward the rear end of the gear 1 from the shoulder portion 16 in the portion forming the chamfer portion 5, the material is The chamfer portion 5 is blocked to prevent defects from occurring in the chamfer portion 5.

(Prior Art) However, in such a conventional forging die, the round punch 26 is also used to form the chamfer part 5, and therefore the chamfer part 5 is shown by a broken line F in FIG. As such, a lack of thickness may occur at the outer peripheral portion of the tip of the chunf γ portion 5. This is because the technique does not fully penetrate into this part. Furthermore, in the conventional forging die, as shown in FIG. 5, an extra extruded portion G is formed on the rear end surface of the product gear 1, and this needs to be removed in a post-process.

The present invention has been made in view of the problems of the prior art described above, and it is an object of the present invention to make it possible to mold a gear with a desired shape on one side of the chamfer with high precision.

(Means for Solving the Problems) - The present invention for achieving the object L is a forging gear for forging a gear having an annular shape, a thinner part on the front end side, and spline teeth formed on the outer periphery of the rear end part. In the mold, a die for forming a mold surface for shaping the outer circumferential shape of the gear and a tooth portion for forming the spline teeth in the die hole, and a die for disposing a mold surface for shaping the outer circumferential shape of the gear in the die hole, and a tip of the gear that is mounted in the die hole so as to be movable in one direction. A lower mold is provided with a lifter sleeve for forming the side ends, a vertically movable mold is provided above the lower mold, a slider is provided on the mold so as to be movable in the horizontal direction, and a slider is provided on the mold so as to be movable horizontally, and A first mandrel that enters the inside and comes into contact with the inner circumferential surface of the gear is fixed to the slider, and a first mandrel is provided surrounding the first mandrel and has a diameter slightly smaller than the inner diameter of the cutting edge of the teeth of the die hole. A round punch having an outer circumferential diameter of 6 is provided, and a second mandrel is further fixed to the slider at a position apart from the first mandrel, and the second mandrel is bent to form a hole corresponding to the die hole. A forging die for gear processing, characterized in that the slider is provided with a drive device for moving the first and second mandrels alternately to positions facing the die hole. be.

(Function) The gear element 4A is loaded onto the lower die, and the first
By inserting the mandrel and round punch into the die, it is first preliminarily bent, and the south part of the spline is extended into the teeth of the die.

Next, with the Gael H placed on the die, move the slider horizontally to position the second punch part at the center of the lower die, and form the overhang into the final spline shape using the tooth punch. do. Therefore, by using one die, a round punch and a tooth-shaped punch can be used together.
Process processing can be performed.

(Embodiment) FIGS. 1 and 2 are diagrams showing a forging die for gear processing according to an embodiment of the present invention, and are for processing the gear 1 shown in FIGS. 3 and 4. . The structure of the lower mold is almost the same as that of the forging mold shown in FIG. 5, and the same reference numerals are given to the same members as those shown in FIG.

The lower mold 30 has a die base 11 fixed to a bolster 31.
and a die 14 fixed thereon, and within the center of these, a lifter sleeve 13 is vertically movable via a cushion pad 20 by means of a cushion pin 21.

Above this lower mold 30, an upper mold main body 32 is vertically movable by a drive means (not shown).
2, the slider 33 is movable in the horizontal direction. In order to drive this slider 33 in the horizontal direction,
A hydraulic cylinder 34 is attached to the upper mold body 32. Therefore, this slider 33 is attached to the upper mold body 32.
The cylinder 34 causes the cylinder to move in the vertical direction and the cylinder 34 to move in the horizontal direction. This slider 3
Two limit switches LS are attached to the upper die main body 32 in order to detect the position of the horizontal sliding end of the upper mold body 32.

A first mandrel 35 is fixed to the slider 33, and this first mandrel 35 is connected to the slider 33.
When the upper mold body 32 is lowered toward the lower mold 30 while being positioned at the center of the lower mold 30, it comes into contact with the inner circumferential surface of the grout of the gear 1 and the inner circumferential surface of the lifter sleeve 13. A cylindrical round punch 36 is attached to the outside of the first mandrel 35. This round punch 36
The outer periphery of the die 14 is circular, and its outer diameter is slightly smaller than the inner diameter of the inner circumferential surface of the cutting edge of the tooth portion 17 of the die 14.

Furthermore, a first mandrel 35 is provided on the lower surface of the slider 33.
A second mandrel 40 is attached at a position a predetermined distance away from the second mandrel 40, and a cylindrical tooth-shaped punch 41 is attached to the outer periphery of the second mandrel 40. On the outer periphery of this round punch 41, a round part 42 is formed which has a concavity and convexity relationship opposite to that of the tooth part 17 of the die 14.

Hand 9 for processing gear 1 using a forging die with the above structure The order will be explained.

The gear element is placed in the die 14 of the lower die 30.

Before or after this placement, the slider 33 is moved horizontally by the hydraulic cylinder 34,
The center of the first mandrel 35 is connected to the die hole 13 of the die 14.
decided to be abducted to the center of 1st mandrel 3 to this position
The movement of limit switch 5 is detected by turning on the right switch of the two limit switches LS in FIG.

In synchronization with turning on this limit switch LS, the upper mold body 3
By moving the element 2 downward, the element is plastically deformed in the axial and radial directions by the round punch 36. Figure 2 (
A) shows a state in which processing using the round punch 36 has been completed. The semi-finished product of Gya 1 is indicated by the symbol 1a,
The outer periphery of the rear end portion is extended in the outer radial direction to form a projecting portion H. Since this projecting portion H is inserted into the tooth portion 17, it is uneven in the circumferential direction.

10 Next, after raising the upper mold body 32 by -L, the hydraulic cylinder 34 is driven again to position the center of the second mandrel 40 at the center of the die hole 13.

This position is detected by the limit switch LS located on the left side in FIG. Then, when the upper mold body 32 is lowered again in this state, the toothed punch 41
The spline portion 4 of the gear 1 is formed by plastic working so that the overhanging portion H is crushed. In this way, the spline part 5 is formed by processing only the protruding part H with the tooth-shaped punch 41, and the spline part 5 is formed by the tooth part 17 formed on the die 14 from the inside to the outside. It was decided that it would be formed with high precision into a shape that corresponds to the shape of. In addition, the back side of the gear 1 is made flat by the tooth-shaped punch 42, which facilitates machining of the gear 1 in a subsequent process.

The forging die of the present invention is a round punch 36? Since the shaped bunch 42 is shared by one toothed die 14, it becomes possible to machine a high quality gear by using only one expensive toothed die 14.

(Effects of the Invention) As described above, according to the present invention, a round punch in which the spline teeth of the gear protrude from one tooth-shaped punch;
Since the tooth profile punch that processes only the south spline is made to enter in sequence, first the south spline is preliminarily processed using the round punch, and then only the south spline is machined using the tooth profile punch. Thus, the spline teeth are formed into a desired shape from the inner circumferential side to the outer circumferential end in correspondence with the teeth of the die. Further, since the shape of the gear is finally formed by a tooth-shaped punch, the end face of the rear end portion is flat, which facilitates subsequent machining.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a forging die for gear processing according to an embodiment of the present invention, FIG. ) is a cutting diagram showing the gear formed into the final shape by the tooth punch, Figure 3 is a front view showing the gear formed by Honhatsumon's forging 12 molding, and Figure 4 is the FIG. 5 is a sectional view showing a conventional forging die. 1... Gear, 4... Spline tooth, 5... Part of chamfer, 14... Die, 15... Tapered surface,
16...Shoulder part, 17...Tooth part, 18...Step part, 2
2... Lifter sleeve, 25... Mandrel, 3
2... Upper mold body, 33... Slider, 35...
1st mandrel, 40...2nd mandrel.

Claims (1)

[Claims] In a gear processing forging die for forging a gear having an annular shape with a thinner part on the tip side and spline teeth formed on the outer periphery of the rear end, a die surface for forming the outer peripheral shape of the gear and a tooth part for forming the spline teeth. A lower mold is provided with a die having a die in a die hole, and a lifter sleeve that is installed in the die hole so as to be movable up and down and molds the tip side end surface of the gear,
An upper die movable up and down is provided above the lower die, a slider is provided on the upper die so as to be movable in the horizontal direction, and a first mandrel is inserted into the die hole and comes into contact with the inner peripheral surface of the gear. A round punch is fixed to the slider, is provided around the first mandrel, and has an outer diameter slightly smaller than the inner diameter of the cutting edge of the teeth of the die hole; A second mandrel is fixed at a position apart from the first mandrel, a tooth-shaped punch is provided surrounding the second mandrel and has teeth corresponding to the die hole, and the slider is further provided with a first,
A forging die for gear processing, characterized in that a drive device is provided for moving the second mandrels alternately to positions facing the die holes.