JPH0425321A - Clutch gear manufacturing method - Google Patents

Abstract

PURPOSE:To increase productivity significantly by removing an excess thickness of a spline tooth section of a semi-processed forged clutch gear by means of a ring shape die in the case of manufacturing a clutch gear used in a synchromesh mechanism. CONSTITUTION:A semi-processed clutch gear 6 is forged by being provided with a spline tooth section 6a having an excess thickness 6d in the top part 6b in the outer peripheral section as well as having a chamfer section 6c projecting in a V shape on an edge section. Then the semi-processed clutch gear 6 is pressed into a die hole 7b having both a dimension and a form corresponding to those of the spline tooth section 6a in the outer peripheral section of the clutch gear of a ring shape die 7 from its chamfer section 6c side. In the case of this pressing in, the top part 6b is sheared and removed by its excess thickness 6d from a corner section 7d between a tooth shape inner peripheral surface 7b and a groove section 7c. Accordingly, each spline tooth section 6a of the semi-processed clutch gear 6 comes to have a new top section 6e having no underfill in the corner of the chamfer section 6c side.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is used for a synchromesh mechanism that facilitates the gear shifting operation of a manual transmission of an automobile. A method for manufacturing a clutch gear having a chamfer portion protruding in a seven-shape shape at one end so as to easily mesh with spline teeth of a clutch gear, and a plurality of spline teeth extending in an axial direction on an outer peripheral portion thereof. It is related to.

(Prior Art) When manufacturing a clutch gear as described above, normally, as shown in FIG. 3, the knockout sleeve 4, and the mandrel 5 are cold forged to form a large number of splines extending in the axial direction and having a chamfer portion 6b protruding in a figure 7 shape at one end, as shown in FIG. A clutch gear semi-finished product 6 having teeth 6c on the outer circumferential portion is formed, and then, as shown by the imaginary lines in FIG. 13, both end surfaces and the inner circumferential surface of the clutch gear semi-finished product 6 are finished by turning. It goes through a process called.

By the way, in the above-mentioned cold forging, due to constraints on material flow, clogging of mold release agent, etc., the chamfered portion 6c side of the top portion 6b, which has the maximum outer diameter, of the spline tooth portion 6a of the clutch gear semi-finished product 6 is As shown in FIG. 14, it is unavoidable that a lack of thickness A occurs at the corner of the clutch, but such a lack of thickness A reduces the effective area of the chamfer portion, which is undesirable in terms of durability of the clutch gear.

For this reason, conventionally, in anticipation of the occurrence of the underfill A, the top 6b of the spline tooth portion 6a of the clutch gear semi-finished product 6 is made higher than the top of the clutch gear by the amount of the underfill A, as shown in FIG. By cold forging the clutch gear semi-finished product 6, an extra thickness 6d is provided on the spline tooth portion 6a, and during the subsequent finishing turning of both end surfaces and the inner circumferential surface of the clutch gear semi-finished product 6. , The outer peripheral portion is also rough-turned and finish-turned, and the top portion 6b of the spline tooth portion 6a is shaved off by the amount of the excess thickness 6d that has the missing thickness A, as shown by the imaginary lines in FIGS. 13 and 14. This prevents any underfill from remaining at the corner of the top of the spline tooth portion of the clutch gear as a product on the chamfer portion side.

(Problems to be Solved by the Invention) However, in such a conventional clutch gear manufacturing method, as shown in FIG.
Burrs B are generated on the side edges of the newly formed top portion 6e of the spline tooth portion 6a and the side edge of the chamfer portion 6c, and this burr B greatly impairs the shift operability of the manual transmission. In particular, it is necessary to completely remove it by puffing or polishing.

Moreover, it is very difficult to remove the burr B from the spline tooth portion 6a because it requires work on a narrow area and if too much is removed, there will be insufficient thickness.

For this reason, the conventional manufacturing method described above has a problem in that the finishing work requires an extremely large number of man-hours, making it extremely difficult to increase productivity.

The present invention provides a manufacturing method that advantageously solves these problems.

(Means for Solving the Problems) A method for manufacturing a clutch gear according to the first invention of this application provides a clutch gear having a spline tooth portion on its outer circumferential portion having a chamfer and a chamfer portion projecting in a 7-shape at one end. When manufacturing a gear, first, a clutch gear semi-finished product is forged, which has a chamfer part protruding in a figure 7 shape at one end and a spline tooth part with extra thickness at the top part on the outer periphery, and then a ring-shaped die is used. The semi-finished clutch gear is press-fitted into a die hole having a size and shape corresponding to the spline teeth on the outer circumferential portion of the clutch gear from its chamfer side, and the excess material at the top of the spline teeth is removed. This is characterized by shearing and removal using the corners of the die hole.

Further, in the method for manufacturing a clutch gear of the second invention according to this application, when manufacturing a clutch gear having a spline tooth portion on an outer peripheral portion having a chamfer portion protruding in a 7-shape shape at one end, first, one end of the clutch gear is manufactured. The chamfer part has a chamfer part projecting in a figure 7 shape at the top, and the end part of the extra part recedes from the chamfer part, so that the ends of the extra part and the chamfer part form a stepped shape. A clutch gear semi-finished product is forged, and the clutch gear semi-finished product is provided with spline teeth on the outer peripheral portion, the peripheral surface of the stepped portion being slightly inclined radially inward as it approaches the edge, and then the clutch gear The present invention is characterized in that excess thickness at the top of the spline tooth portion of the semi-finished product is removed.

(Function) In the method of the first invention, the extra thickness provided at the top of the spline tooth portion of the forged clutch gear semi-finished product is formed from the chamfer portion side at the corner of the die hole of the ring-shaped die. Since the spline teeth are sheared away, no burrs are formed on the side edges of the tops of the spline teeth and on the side edges of the chamfer portions.

Therefore, according to the method of the first invention, it is not necessary to remove the flakes from the edge of the top of the spline tooth portion, especially the edge on the side of the chamfer portion, and the productivity of the clutch gear can be greatly improved. At the same time, it is possible to improve the shape accuracy of the corner part of the chamfered part, and since the excess thickness is removed by shearing with a ring-shaped die instead of turning, the accuracy of the maximum outer diameter of the clutch gear can also be improved. I can do it.

In addition, in the method of the second invention, the top of the spline tooth portion of the forged clutch gear semi-finished product is provided with a step that is set back from the chamfer portion of the spline tooth portion and the end portion and the chamfer portion. The extra thickness is provided so that it forms a shape and is slightly inclined towards the peripheral surface or edge of the stepped part, and the extra thickness is removed, so that the blade of the tool does not touch the spline teeth when removing the extra thickness. It does not touch the edge of the top chamfer section side at all, and therefore not only a break but also a minute burr does not occur there.

Therefore, according to the method of the second invention, it is possible to completely eliminate the work of removing burrs and burrs from the chamfered portion of the spline tooth portion, and it is possible to greatly improve the productivity of clutch gears, and also to greatly improve the productivity of the chamfered portion of the spline tooth portion. It is possible to improve the shape accuracy of the corner portion of the

(Example) Hereinafter, an example of the above invention will be described in detail based on the drawings.

FIG. 1 is a cross-sectional view showing a shear die used in an embodiment of the clutch gear manufacturing method of the first invention, in which 7 is a ring-shaped die, and 8 is a die holder that fixedly supports the ring-shaped die. are shown respectively.

The ring-shaped die 7 here has a die hole 7a in the center, as shown in a plan view in FIG. 2 and a partially enlarged plan view in FIG. Near the upper end, there is a tooth-shaped inner circumferential surface 7b having substantially the same size and shape as the spline teeth of the clutch gear as a product. In the surrounding parts, Fig. 4 and Fig. 5 show a view from the direction of arrow C in Fig. 3 and ■.
As shown in the cross-sectional view taken along line -V, the V-shaped end of the extra thickness 6d of the spline portion 6a of the clutch gear semi-finished product 6 on the side of the chamfer portion 6c as shown in FIG. The groove 7c has a V-shaped groove 7c corresponding to the groove 7c, and this groove 7c is tightly fitted with the V-shaped end of the extra thickness 6d, and the clutch gear semi-finished product 6 is inserted into the ring-shaped die 7. Can be accurately positioned concentrically.

Here, a clutch gear is manufactured using such ring-shaped die 7 as follows.

That is, first, as shown in FIG. 12, as in the conventional case,
By putting a ring-shaped material 2 into a forging die 1 and cold forging the material 2 with the die 1, punch 3, knockout sleeve 4, and mandrel 5, the 13th
As shown in the figure, a clutch gear semi-finished product 6 is formed which has an extra thickness 6d substantially equal to the height of the missing thickness A at each top 6b of a large number of spline portions 6a on the outer periphery.

Next, the clutch gear semi-finished product 6 is placed on a ring-shaped die 7 fixed to a bolster 9 of a press machine with the chamfer part 6c facing downward, as shown on the right side in FIG.

During this placement, the clutch gear semi-finished product 6 is assembled as shown in FIG. dice 7
The extra thickness 6d is positioned concentrically with the groove 7c, as shown by the imaginary lines in FIG.

Thereafter, as shown in the left half of FIG. 1, the sleeve-shaped punch 9 fixed to the slide IO of the press machine is lowered based on the operation of the press machine, and the punch 9 presses the clutch gear half. The product 6 is press-fitted into the die hole 7a of the ring-shaped die 7.

During this press-fitting, each of the top portions 6b is sheared off by the corner portion 7d of the tooth-shaped inner circumferential surface 7b and the groove portion 7c, as shown in FIG. Each spline portion 6a of the gear semi-finished product 6 has substantially the same dimensions and shape as each spline portion of the clutch gear as a product, and has the top portion 6 as shown in FIG.
The missing thickness A at the corner on the chamfer part 6c side of b is removed, and a new top part 6e with no missing thickness at the corner on the chamfer part 6c side is obtained.

Moreover, since this new top portion 6e is formed by shearing and removing the excess thickness 6d from the chamfer portion 6c side, no burrs are formed on the side edges of the new top portion 6e and the edges on the chamfer portion 60 side. do not have.

Here, in order to make the sheared surface of the new top portion 6e a neatly finished surface, it is preferable that the corner portion 7d is slightly rounded as shown in FIG. 5 rather than having a sharp edge.

The clutch gear semi-finished product 6 that has passed through the tooth-shaped inner circumferential surface 7b of the ring-shaped die 7 falls through the relief part 7e of the die hole 7a, which has an inner diameter sufficiently larger than that part, and is then inserted into the die holder. Slanted shoe H disposed within 8
a, and is discharged to the outside by the chute 8a through the opening 8b of the die holder 8, as shown by the arrow in FIG.

Thereafter, as shown by the phantom lines in FIG. 8, both end surfaces and the inner circumferential surface of the clutch gear semi-finished product 6 are finished by turning.

Therefore, according to the method of this embodiment, the spline tooth portion 6a
It is possible to eliminate the work of removing the edges of the side edges of the top part 6e and the side edges of the chamfer part 6c, and the productivity of the clutch gear can be greatly improved, and the shape accuracy of the corner part of the chamfer part can be improved. Furthermore, since the excess thickness 6d is removed by shearing using the ring-shaped die 7 rather than by turning, the accuracy of the maximum outer diameter of the clutch gear can also be improved. In addition, since turning, which is an interrupted cutting process, is not performed to remove the excess thickness 6d, chipping of the tip of the cutting tool hardly occurs.

By the way, when shearing the clutch gear semi-finished product 6 using the ring-shaped die 7, depending on the processing speed, the material of the die 7, etc., the spline tooth portion 6a may be cut as shown in FIG.
There is a slight burr D on the edge of the chamfer part 6c side of the top part 6e.
may occur.

Although this burr D is not as bad as the burr B caused by the turning process, it impairs the shift operability of the manual transmission, so it is preferable to completely remove it.

FIG. 1θ is a sectional view showing a forging die used in an embodiment of the clutch gear manufacturing method of the second invention, which can effectively prevent the occurrence of such burrs D, and this forging die 12 is Similar to the conventional forging die 1, it has a groove portion 12a corresponding to the spline tooth portion of the clutch gear, and has a V-shaped abutting portion 12b at the lower end of the groove portion 12a corresponding to the chamfer portion. 12a
is deeper than the height of the spline teeth of the clutch gear so as to provide extra thickness at the top of the spline teeth of the clutch gear semi-finished product, but the V-shaped abutment at the lower end of the groove bottom 12c forms the extra thickness. The part is the conventional forging die 1
In contrast, it is located slightly above and parallel to the V-shaped abutting part at the lower end near the opening of the groove, and therefore the abutting part 12b has two steps. Moreover, the circumferential surface 12d of the stepped portion is slightly inclined radially inward as it approaches the lower end.

In this embodiment, first, cold forging is performed in the same manner as in the conventional method using the forging die 12 to form a clutch gear semi-finished product 13 as shown in FIG.

Similar to the clutch gear semi-finished product 6, this clutch gear semi-finished product 13 has a chamfer portion 13c projecting in a V-shape at one end, and a spline tooth portion 13a having an extra thickness 13d at the top portion 13b on the outer peripheral portion. However, unlike the clutch gear semi-finished product 6, the ends of the extra thickness 13d are set back from the chamfer part 13c, and the ends of the extra thickness 13d and the chamfer part 13c form a stepped shape as shown in the figure. Furthermore, the circumferential surface 13e of the stepped portion is slightly inclined radially inward as it approaches the edge.

Then, a lack of thickness A occurs at the end of the excess thickness 13d,
Since the material is forcibly poured into the chamfer portion 13c by the amount that the end of the excess thickness 13d has receded, there is little or no shortage of thickness.

Next, here, the clutch gear semi-finished product 13 is press-fitted into the die hole 7a of the ring-shaped die 7 described in the previous embodiment from its chamfer portion 13b side.

By this press-fitting, each of the top portions 13b is sheared off by the corner portion 7d by an amount of excess thickness 13d, and thereby each spline portion 13a of the clutch gear semi-finished product 13 is substantially connected to each spline portion of the clutch gear as a product. In addition to having the same size and shape, the missing thickness A is removed, and a new top portion with no missing thickness is provided at the corner on the side of the chamfer portion 13c.

Moreover, this new top part only has the extra thickness 13d whose end is retracted from the chamfer part 13c.
Since it was formed by shearing and removing the edge of the chamfered portion 13c without applying the corner 7d of the die 7 to the edge of the chamfered portion 13c from the side, the side edge of the new top and the edge of the chamfered portion 13c are Not only Paris but also minute burrs do not occur at all.

Thereafter, as in the previous embodiment, both end surfaces and the inner circumferential surface of the clutch gear semi-finished product 13 are finished by turning.

Therefore, according to the method of this embodiment, the spline tooth portion 13
It is possible to completely eliminate the need to remove the burrs and minute burrs on the side edges of the top of the top part a and on the side edges of the chamfer part 13c, and the productivity of the clutch gear can be greatly improved. The shape accuracy of the corner portion of the clutch gear can be improved, and since the excess thickness 13d is removed not by turning but by shearing with the ring-shaped die 7 as in the previous embodiment, the maximum outer diameter dimensional accuracy of the clutch gear can be improved. It can also be improved.

Although the above description has been made based on the illustrated example, the present invention is not limited to the above-mentioned example. For example, after forging the clutch gear semi-finished product 13 shown in FIG. 11, the excess thickness 13d is removed by turning. Even in this way, it is possible to effectively prevent the occurrence of burrs on the edge of the chamfered portion 13c at the new top of the spline tooth portion 13a, so the number of man-hours required for finishing the burr removal can be significantly reduced compared to the conventional method. As a result, the productivity of the clutch gear can be improved, and the shape accuracy of the corner portion of the chamfer portion can be improved.

Further, the forging of the clutch gear semi-finished product is not limited to cold forging, but may be warm or hot forging.

(Effect of the invention) Thus, according to the clutch gear manufacturing method of the present invention,
In the first aspect of the present invention, it is possible to eliminate the need for removing debris from the edge of the top of the spline tooth portion, especially the edge on the side of the chamfer portion,
The productivity of the clutch gear can be greatly improved, and the shape accuracy of the corner portion of the chamfered part can be improved.Moreover, the excess metal is removed by shearing with a ring-shaped die instead of turning. The accuracy of the maximum outer diameter dimension of the clutch gear can also be improved, and in the second invention, it is possible to completely eliminate the work of removing burrs and burrs from the chamfered portion of the spline teeth, thereby improving the productivity of the clutch gear. It is possible to significantly improve the shape accuracy of the corner portion of the chamfer portion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a shear die used in an embodiment of the clutch gear manufacturing method of the first invention of this application; FIG. 2 is a plan view showing a ring-shaped die of the shear die; FIG. 4 is a plan view showing an enlarged main part of the ring-shaped die, FIG. 4 is a view taken from the direction of arrow C in FIG. 3, and FIG. 5 is a sectional view taken along the line ■-V in FIG. 3. , FIGS. 6 to 8 are explanatory diagrams showing the process of removing excess metal from the clutch gear semi-finished product in the above embodiment, respectively. FIG. 9 shows the occurrence of minute burrs due to the shearing removal of the excess metal from the clutch gear semi-finished product. FIG. 10 is a sectional view showing a forging die used in an embodiment of the clutch gear manufacturing method of the second invention according to this application; FIG. 11 is a forging in the above embodiment. FIG. 12 is an enlarged perspective view of the main part showing the state of excess metal of the clutch gear semi-finished product; FIG. 12 is a sectional view showing a conventional forging die used in the conventional manufacturing method and the manufacturing method of the first invention; FIG. 13 14 is a side view showing a partial cross section of a half of the clutch gear semi-finished product cold-forged by the conventional forging die; FIG. 14 is a perspective view showing an enlarged main part of the clutch gear semi-finished product; FIG. 15 is a view seen from the direction of arrow E in FIG. 14. 6.13...Clutch gear semi-finished products 6a, 13a...Spline tooth portions 6b, 13b
...Top part 6c, 13c'--Chamfer part 6d, 13d--Excess meat 7--...
Ring-shaped die 7b--inner peripheral surface 7tl
- Corner 12-1 Forging die 12d- Surrounding surface

Claims (1)

[Scope of Claims] 1. When manufacturing a clutch gear having a spline tooth portion on the outer peripheral portion having a chamfer portion projecting in a V-shape at one end, first, a chamfer portion projecting in a V-shape at one end. (6c)
A clutch gear semi-finished product (6) having a spline tooth portion (6a) having an extra thickness (6d) at the top portion (6b) on the outer peripheral portion is forged, and then the clutch gear is forged with a ring-shaped die (7). The clutch gear semi-finished product is press-fitted from the chamfer side into a die hole (7b) having a size and shape corresponding to the spline teeth on the outer circumference of the gear, and the excess material at the top of the spline teeth is inserted into the die. A method for manufacturing a clutch gear, characterized in that shearing and removal are performed using a corner (7d) of a hole. 2. When manufacturing a clutch gear having a spline tooth portion on its outer circumferential portion having a chamfer portion projecting in a V-shape at one end, first, a chamfer portion (13b) projecting in a V-shape at one end.
) and has an extra thickness (13d) at the top (13c), the end of the extra thickness recedes from the chamfer part, and the ends of the extra thickness and the chamfer part form a stepped shape,
A clutch gear semi-finished product (13) is provided with a spline tooth portion (13a) on the outer peripheral portion, and the peripheral surface (13e) of the stepped portion is slightly inclined radially inward as it approaches the edge. A method of manufacturing a clutch gear, comprising forging the clutch gear, and then removing excess thickness at the top of the spline tooth portion of the clutch gear semi-finished product.