JP2600438B2 - Manufacturing method of clutch gear - Google Patents

Description

The present invention is used in a synchromesh mechanism for facilitating the shifting operation of a manual transmission of an automobile, and includes an inner peripheral portion of a coupling sleeve of the synchromesh mechanism. The present invention relates to a method of manufacturing a clutch gear having a plurality of axially extending spline teeth on an outer peripheral portion having a chamfer portion protruding in a V-shape at one end so as to easily mesh with spline teeth. is there.

(Prior Art) When a clutch gear as described above is manufactured, usually, as shown in FIG. 12, a ring-shaped material 2 is put into a forging die 1 and the material 2 is punched with the die 1. 13, a plurality of splines extending in the axial direction having a chamfer portion 6b protruding in a V-shape at one end as shown in FIG. 13 by cold forging with the knockout sleeve 3, the mandrel 5, and the mandrel 5. A clutch gear semi-finished product 6 having teeth 6c on the outer peripheral portion is formed, and then both end surfaces and an inner peripheral surface of the clutch gear semi-finished product 6 are finished by turning as shown by phantom lines in FIG. It has gone through the process.

In the above-described cold forging, the spline teeth 6a of the clutch gear semi-finished product 6 have the maximum outer diameter on the side of the chamfer 6c on the top 6b due to restrictions on material flow and clogging of the release agent. It is inevitable that underfill A occurs at the corners of the clutch gear as shown in FIG. 14, but such underfill A is not preferable in terms of durability of the clutch gear since the effective area of the chamfer portion is reduced.

For this reason, conventionally, in anticipation of the occurrence of the underfill A, the top 6b of the spline teeth 6a of the clutch gear semi-finished product 6 is higher than the top of the clutch gear by the amount of the underfill A, as shown in FIG. In this way, the clutch gear semi-finished product 6 is cold forged so that the spline teeth portion 6a is provided with extra thickness 6d, and when turning and finishing the both end surfaces and the inner peripheral surface of the clutch gear semi-finished product 6 thereafter. In addition, rough turning and finish turning are also performed on the outer peripheral portion, and as shown by phantom lines in FIGS. 13 and 14, the top portion 6b of the spline tooth portion 6a is cut off by an amount corresponding to the excess thickness 6d having the underfill A. As a result, no underfill is left at the corner of the top of the spline teeth of the clutch gear as a product on the chamfer side.

(Problems to be Solved by the Invention) However, in such a conventional method of manufacturing a clutch gear, as shown in FIG. 15, the spline is turned by turning an outer peripheral portion to cut off the top 6b of the spline teeth 6a by the excess thickness 6d. Burrs B are formed on the side edges of the newly formed top portions 6e of the tooth portions 6a and on the side edges of the chamfer portions 6c, and the burrs B greatly impair the shifting operability of the manual transmission. In particular, an operation of completely removing buffing and polishing by polishing is required.

In addition, it is very difficult to remove the burrs B of the spline teeth 6a because it is necessary to work on a narrow portion, and if the burrs are taken too much, the portion becomes underfilled.

For this reason, in the above-mentioned conventional manufacturing method, there is a problem that the number of steps required for the finishing operation is extremely large and it is extremely difficult to enhance the productivity.

The present invention provides a manufacturing method that advantageously solves such a problem.

(Means for Solving the Problems) A method of manufacturing a clutch gear according to a first aspect of the present invention is directed to a clutch gear having a spline tooth portion having a chamfer portion protruding in a V-shape at one end portion on an outer peripheral portion. In manufacturing, first, forging a clutch gear semi-finished product having a chamfer portion protruding in a V-shape at one end and having a spline tooth portion having excess thickness at the top portion on an outer peripheral portion, and then a ring-shaped die, The clutch gear semi-finished product is press-fitted from the chamfer portion side into a die hole having a size and a shape corresponding to a spline tooth portion of the outer peripheral portion of the clutch gear, and the excess thickness at the top of the spline tooth portion is formed in the die hole. Characterized by being removed by shearing at the corners.

Further, the method for manufacturing a clutch gear according to the second invention according to the present application, when manufacturing a clutch gear having a spline tooth portion having a chamfer portion protruding in a V-shape at one end portion on an outer peripheral portion, firstly, at one end, Portion has a chamfered portion protruding in a V-shape and has a surplus at the top, the end of the surplus retreats from the chamfered portion, and the end of the surplus and the chamfer become a step-like shape. Forging a clutch gear semi-finished product having a spline tooth portion on the outer peripheral portion where the peripheral surface of the step portion is slightly inclined inward in the radial direction as approaching the edge, and thereafter, the clutch gear It is characterized by removing excess material at the top of the spline teeth of the semi-finished product.

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

Therefore, according to the method of the first aspect of the invention, it is unnecessary to remove the burrs at the top edge of the spline teeth, particularly at the chamfer-side edge, and the productivity of the clutch gear can be greatly improved. It is possible to improve the accuracy of the shape of the corners of the chamfer part, and to remove excess material by shearing with a ring-shaped die instead of turning, thereby improving the maximum outer diameter dimensional accuracy of the clutch gear. Can be.

Further, in the method of the second invention, at the top of the spline teeth of the semi-finished forged clutch gear, the end is retracted from the chamfer of the spline teeth and the end and the chamfer are stepped. In the shape, and the excess surface is provided so that the peripheral surface of the step is slightly inclined toward the edge,
Since the excess thickness is removed, the blade of the tool does not hit the edge of the spline teeth at the chamfer side at the time of removal of the excess thickness, so that not only burrs but also fine burrs do not occur there.

Therefore, according to the method of the second aspect of the present invention, the operation of removing the burr and the burr of the chamfer portion of the spline tooth portion can be completely unnecessary, and the productivity of the clutch gear can be greatly improved and the chamfer portion can be improved. Can improve the shape accuracy.

(Example) Hereinafter, an example of the above-mentioned invention is described in detail based on a drawing.

FIG. 1 is a sectional view showing a shearing die used in an embodiment of the method for manufacturing a clutch gear according to the first invention.
Denotes a ring-shaped die, and 8 denotes a die holder for fixedly supporting the ring-shaped die.

As shown in a plan view of FIG. 2 and a partially enlarged plan view of FIG. 3, the ring-shaped die 7 has a die hole 7a at a central portion, and has a Near the upper end, having substantially the same dimensions and shape as the spline teeth of the product clutch gear,
4 and 5 are provided on the upper surface of the die 7 around the die hole 7a.
As shown in FIG. 3 as viewed from the direction of arrow C in FIG. 3 and a sectional view taken along the line VV, the spline portion 6a of the clutch gear semi-finished product 6 as shown in FIG. V corresponding to the V-shaped end of the surplus portion 6d on the side of the chamfer portion 6c.
The groove 7c has a surplus portion 6d.
And the clutch gear semi-finished product 6 can be accurately positioned concentrically with the ring-shaped die 7.

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

That is, first, as in the prior art, as shown in FIG.
A ring-shaped material 2 is put into a forging die 1 and the material 2 is cold-forged with a die 1, a punch 3, a knockout sleeve 4, and a mandrel 5 to form an outer peripheral portion as shown in FIG. Each spline part 6a
A semifinished clutch gear 6 having a surplus thickness 6d substantially equivalent to the underfill A is formed on 6b.

Next, as shown in the right half of FIG. 1, the clutch gear semi-finished product 6 is placed on the ring-shaped die 7 fixed to the bolster 9 of the press machine with the chamfer portion 6c facing downward.

At the time of this mounting, the clutch gear semi-finished product 6 is fitted with the V-shaped end of the excess thickness 6d of each spline portion 6a and the V-shaped groove 7c as shown in FIG. The excess thickness 6d is located on the groove 7c as shown by the imaginary line in FIG.

Thereafter, as shown in the left half of FIG. 1, the sleeve-shaped punch 9 fixed to the slide 10 of the press machine is lowered based on the operation of the press machine, and is pressed by the punch 9 to press the clutch gear half. The product 6 is pressed into the die hole 7a of the ring-shaped die 7.

At the time of this press-fitting, as shown in FIG. 7, each of the top portions 6b is sheared and removed by an excess portion 6d by a corner portion 7d of the tooth-shaped inner peripheral surface 7b with the groove portion 7c. The spline portions 6a of the semi-finished gear 6 have substantially the same dimensions and shape as the spline portions of the clutch gear as a product, and the corners on the chamfer portion 6c side of the top portion 6b as shown in FIG. The meat A is removed, and a new top portion 6e having no underfill is provided at the corner on the chamfer portion 6c side.

Moreover, this new top 6e replaces excess 6d with chamfer 6c.
Since it is formed by shearing off from the side, no burrs are formed on the side edge of the new top portion 6e and the edge of the chamfer portion 6c.

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

Thus, the clutch gear semi-finished product 6 that has passed through the toothed inner peripheral surface 7b of the ring-shaped die 7 falls inside the relief portion 7e of the die hole 7a having an inner diameter sufficiently larger than that, and the die holder. The chutes 8a come into contact with the inclined chutes 8a arranged in the inside 8 and are discharged to the outside through the openings 8b of the die holder 8 as shown by arrows in FIG.

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

Therefore, according to the method of this embodiment, the spline teeth 6a
The burr removal work on the side edge of the top 6e and the side edge of the chamfer 6c can be eliminated, greatly improving the productivity of the clutch gear and improving the shape accuracy of the corners of the chamfer. Can be made to survive
Since the removal of 6d is performed not by turning but by shearing with the ring-shaped die 7, the maximum outer diameter dimensional accuracy of the clutch gear can also be improved. In addition, since turning processing for intermittent cutting is not performed to remove the excess thickness 6d, chipping of the cutting tool hardly occurs.

By the way, during the shearing of the clutch gear semi-finished product 6 by the ring-shaped die 7, depending on the processing speed, the material of the die 7, and the like, as shown in FIG.
A small burr D may be generated at the edge of the top 6e of the chamfer 6c on the side of the chamfer 6c.

The burr D is not as good as the burr B due to the turning process, but impairs the shift operability of the manual transmission. Therefore, it is preferable to completely remove the burr D.

FIG. 10 is a cross-sectional view showing a forging die used in an embodiment of the method for manufacturing a clutch gear according to the second aspect of the present invention, which can effectively prevent the generation of the burr D. Similar to the conventional forging die 1, the groove 12a has a groove 12a corresponding to the spline teeth of the clutch gear, and has a V-shaped butting portion 12b at the lower end of the groove 12a corresponding to the chamfer. 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 lower end of the groove bottom 12c that forms the excess is provided. Unlike the conventional forging die 1, the abutting portion is located slightly above and parallel to the V-shaped abutting portion at the lower end near the opening of the groove, so that the abutting portion 12b has two steps in a stepwise manner. ing. In addition, here, the peripheral surface 12d of the step is slightly inclined so as to approach radially inward as approaching the lower end.

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

Similar to the clutch gear semi-finished product 6, the semi-finished clutch gear 13 has a chamfer portion protruding in a V-shape at one end.
The outer peripheral portion of the clutch gear semi-finished product 6 has a spline tooth portion 13a having a spline tooth portion 13a having a top portion 13b and a surplus portion 13d.
Retreating from 3c, the end of the excess 13d and the chamfer 1
3c is stepped as shown in the figure, and the peripheral surface 13e of the step is slightly inclined so as to move inward in the radial direction as approaching the edge.

And the underfill A is generated at the end of the surplus 13d,
Material is forcibly poured into the chamfer portion 13c by an amount corresponding to the retreated end of the surplus portion 13d, so that little or no underfill occurs.

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

By this press-fitting, each of the top portions 13b is sheared and removed by the corner portions 7d by the excess thickness 13d, whereby each spline portion 13a of the clutch gear semi-finished product 13 substantially corresponds to each spline portion of the clutch gear as a product. With the same size and shape, the underfill A is removed, and a new top without a underfill is provided at the corner on the chamfer portion 13c side.

Moreover, this new top portion is sheared away from the chamfered portion 13c only from the chamfered portion 13c without any corner 7d of the die 7 being applied to the edge of the chamfered portion 13c. The new top edge and the chamfer 13c
No burrs or fine burrs are formed on the side edges.

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

Therefore, according to the method of this embodiment, the spline teeth 13
The work of removing burrs and fine burrs on the side edge of the top part of a and the side edge of the chamfer part 13c may be completely unnecessary,
The productivity of the clutch gear can be greatly improved, and the shape accuracy of the corner portion of the chamfer portion 13c can be improved. In addition, the removal of the excess thickness 13d is performed not by turning but by using a ring as in the previous embodiment. Since the cutting is performed by the shearing die 7, the dimensional accuracy of the maximum outer diameter of the clutch gear can be improved.

As described above, the present invention has been described based on the illustrated example. However, the present invention is not limited to the above-described example. For example, after forging a clutch gear semi-finished product 13 shown in FIG. 11, the excess thickness 13d is removed by turning. In this case, it is possible to effectively prevent the occurrence of burrs on the edge of the spline tooth portion 13a on the side of the chanfa portion 13c at the new top, so the man-hour required for deburring is greatly reduced compared to the past. As a result, the productivity of the clutch gear can be improved, and the shape accuracy of the corner of the chamfer can be improved.

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

(Effects of the Invention) According to the method for manufacturing a clutch gear of the present invention, the first invention eliminates the necessity of removing the burrs at the top edge of the spline teeth, particularly at the chamfer side edge. The productivity of the clutch gear can be greatly improved, and the shape accuracy of the corners of the chamfer can be improved. In addition, the removal of excess thickness is performed not by turning but by shearing with a ring-shaped die. Also, the maximum outer diameter dimensional accuracy of the clutch gear can be improved, and in the second invention, it is possible to completely eliminate the work of removing burrs and burrs of the chamfer portion of the spline tooth portion,
The productivity of the clutch gear can be greatly improved, and the shape accuracy of the corner of the chamfer can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a shearing die used in an embodiment of the clutch gear manufacturing method according to the first invention of the present application, FIG. 2 is a plan view showing the above-mentioned shearing ring-shaped die, FIG. FIG. 4 is an enlarged plan view showing a main part of the ring-shaped die, FIG. 4 is a view taken in the direction of arrow C in FIG. 3, and FIG. 5 is a sectional view taken along line VV in FIG. 6 to 8 are explanatory views showing the process of removing the excess thickness of the clutch gear semi-finished product in the above embodiment, and FIG. 9 is a diagram showing the generation of minute burrs accompanying the shear removal of the excess thickness of the clutch gear semi-finished product. FIG. 10 is a cross-sectional view showing a forging die used in an embodiment of the method for manufacturing a clutch gear according to the second invention of the present application, and FIG. 11 is a forging in the above embodiment. FIG. 12 is an enlarged perspective view of a main part showing a state of excess thickness of a clutch gear semi-finished product, and FIG. FIG. 13 is a cross-sectional view showing a conventional forging die used in the method and the manufacturing method of the first invention, and FIG. 13 is a partial cross-sectional view showing a half part of a clutch gear semi-finished product cold-forged by the above-mentioned conventional forging die. FIG. 14 is a perspective view showing an enlarged main part of the semi-finished clutch gear, and FIG. 15 is a view seen in the direction of arrow E in FIG. 6,13 ... Semi-finished clutch gear 6a, 13a ... Spline teeth 6b, 13b ... Top, 6c, 13c ... Chamfer 6d, 13d ... Extra thickness, 7 ... Ring die 7b ... Inner circumference Surface, 7d: Corner 12: Die for forging, 12d: Peripheral surface

Claims (2)

(57) [Claims] When manufacturing a clutch gear having a spline tooth portion on an outer peripheral portion having a chamfer portion protruding in a V shape at one end portion, first, a chamfer portion (6c) protruding in a V shape at one end portion. Forging a clutch gear semi-finished product (6) having a spline tooth portion (6a) on an outer peripheral portion having a surplus portion (6d) on a top portion (6b), and thereafter, the clutch of a ring-shaped die (7) The semi-finished clutch gear is pressed into the die hole (7b) having the size and shape corresponding to the spline teeth on the outer periphery of the gear from the chamfer side, and the excess thickness at the top of the spline teeth is removed from the die. A method for manufacturing a clutch gear, characterized in that the hole is sheared off by a corner (7d) of the hole. 2. When manufacturing a clutch gear having a spline tooth portion having a chamfer portion protruding in a V-shape on one end portion, a chamfer portion (13b) first protruding in a V-shape from one end portion.
And a surplus (13d) at the top (13c), the end of the surplus retreats from the chamfered portion, and the end of the surplus and the chamfer become stair-like, and Semi-finished clutch gear (13) having a spline tooth portion (13a) on the outer peripheral portion of which the peripheral surface (13e) is slightly inclined radially inward as approaching the edge.
And then removing the excess thickness at the top of the spline teeth of the clutch gear semi-finished product.