KR101748391B1

KR101748391B1 - Punch of unified reverse taper toothed forging device

Info

Publication number: KR101748391B1
Application number: KR1020150155038A
Authority: KR
Inventors: 김기백
Original assignee: 한호산업(주)
Priority date: 2015-11-05
Filing date: 2015-11-05
Publication date: 2017-06-27
Also published as: KR20170052917A

Abstract

The present invention relates to a stationary punch of a reverse graded forging apparatus, in which the preform is uniformly placed on a taper pin so as to maintain the stability of the preform, thereby reducing the occurrence of product defects and improving the height deviation of the preform The present invention also relates to a punch for the use of a reverse graded forging apparatus which can reduce the working time since it does not perform an additional correction work for reducing the work amount.

Description

Technical Field [0001] The present invention relates to a punch for an inverted-

[0001] The present invention relates to a punch for staggering a reverse graded forging device, and more particularly to a punch capable of accurately seating on a taper pin in order to realize a precision molding of a taper pin for forming a reverse gradient at each tooth of a spur gear To a stationary punch of a reverse graded forging apparatus for imparting a uniform pressure to a preform.

BACKGROUND ART Generally, a driving force required for a vehicle to travel is largely changed depending on a driving environment. Accordingly, a vehicle is provided with a transmission for changing a torque between an engine and a driving wheel. In a manual transmission, The speed of the vehicle, the speed of the vehicle, the degree of vehicle noise, and operates the clutch, which is a power interrupter, at the same time as the shifting operation.

The dog clutch provided in such a manual transmission is a part which is used after being press-fitted into a speed gear and welded to change the speed of the vehicle while transmitting or interrupting the power of the engine from time to time. The dog clutch rotates in conjunction with the sleeve. Gears, gear clutches, coupling clutches, and the like. In the present invention, it is referred to as a dog clutch.

Referring to Fig. 1, a dog clutch d inserted into a main shaft a of an automobile is used together with a speed gear s. Generally, the dog clutch d and the speed gear s are separately formed The dog clutch d is press-fitted into the speed gear "s, and then welded and integrated.

However, when the dog clutch (d) and the speed gear (s) are molded separately and then press-fitting and welding are performed in a single body, the process becomes excessively long and separate personnel and equipment for press- , The manufacturing cost is increased. In addition, since the two products are connected by welding, there is a problem that the flow of the metal is cut off at the welding site, and the durability is deteriorated.

In order to solve such a problem, in recent years, a method of fabricating a dog clutch d and a speed gear s as a composite integral type has been proposed. In the proposed technique, after a body of a speed gear (s) and a dog clutch (d) are integrally formed, an integral type dog clutch is manufactured and a subsequent step is performed to cut teeth on a body of a speed gear (s) Process such as carburizing heat treatment and shot blasting is carried out to produce a composite integral type gear in which the speed gear (s) and the dog clutch (d) are integrally formed.

On the other hand, the dog clutch (d) has a reverse gradient spur gear in order to prevent a phenomenon that the engagement of the gears with the sleeve is released easily during rotation, and even in the integral type dog clutch in which the speed gear and the dog clutch are integrated, It has a spur gear.

The step of manufacturing the integrated one-piece gear in which the speed gear (s) and the dog clutch (d) are integrally formed will be described. The integrated dog having the speed gear (s) body and the dog clutch After the clutch is manufactured and the precision of the spur gear having the straight type teeth formed on the outer circumferential surface of the integral dog clutch is improved through the cold forging process, the straight type teeth of the dog clutch (d) And formed by forming a backward gradient spur gear having a reverse grading tooth.

The backward gradient forming unit for forming a reverse gradient in the spur gear includes a plurality of taper pins arranged in a radial direction on the upper portion of the lower mold so as to be movable toward the center direction, When the height deviation occurs in the formed body, the punch of the upper mold does not uniformly press the preform, so that the outer diameter of the preform tends to be distorted, and the taper pin can not accurately form a reverse graded tooth.

If the precise graded profile is not formed, defective products may occur or a correction operation for reducing the height deviation of the preform may be additionally performed, so that the working time is increased and the productivity is lowered .

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a spur gear of a preform which is capable of accurately forming a reverse gradient without any error, Which is capable of providing a uniform pressure throughout the preform in order to fix the preform.

In order to achieve the above object, according to the present invention, there is provided a lower mold comprising: a lower mold provided on an upper portion of a lower body and including a reverse gradient forming portion for forming a reverse gradient in each tooth of a spur gear of a dock clutch to form a reverse gradient spur gear; And an upper punch for providing an urging force to move the taper pin of the gradient forming part in a horizontal direction, wherein the upper mold is provided in the upper mold, and when forming a reverse gradient in each tooth of the spur gear, A punch for making a stationary preform is provided with a stationary punch for uniformly resting on a fin so as to stabilize the stability of the preform, characterized in that the stationary punch disperses a load acting on the preform to uniformly pressurize the entire preform So as to uniformly maintain the overall distribution load of the preform, and have at least three sections Generated ejector; And a gas spring provided in the ejector and composed of a nitrogen spring for buffering a pressing force applied to the ejector so as to apply an elastic force to the preform to maintain the stability of the valve.

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According to the punch of the present invention having the above-described constitution, since the preform is allowed to stand evenly on the taper pin, the static stability of the preform is maintained, An additional correction operation for reducing the height deviation of the preform is not performed, so that the operation time can be reduced.

1 is a view showing a coupling relationship between a general speed gear and a dog clutch.
FIGS. 2 to 4 are views showing a reverse graded forging process of the dog clutch according to the present invention.
5 is a perspective view showing a reverse draft forming unit of a backward graded forging apparatus according to the present invention.
Fig. 6 is a bottom view showing a punch for a stair-step forging apparatus according to the present invention; Fig.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 6. FIG.

2 to 4 are process drawings showing a cold forging process for forming a dog clutch having a reverse gradient spur gear according to the present invention.

The dog clutch 10 in which the speed gear body 20 and the dog clutch 30 are integrated in the hot forging process performed in the previous step is made of a preformed body and the preformed body Is subjected to a cold forging process to fabricate an integrated dog clutch (10) having a reverse gradient spur gear.

In the integrated dog clutch 10 in which the speed gear 20 and the dog clutch 30 are integrally formed, generally, the speed gear 20 has a body shape before the teeth are formed on the outer circumferential surface, A spur gear is formed.

The cold forging process for manufacturing an integrated dog clutch includes a first step, which is a cold sizing process for improving the accuracy of the spur gear, and a second step, in which the integrated dog clutch (10) cold- And a second step for forming the reverse gradient spur gear by shaping the type tooth profile to have a reverse gradient.

FIGS. 2 to 4 are diagrams for explaining a cold forging process for forming a dog clutch having a reverse gradient spur gear according to the present invention, in which a straight type spur gear is subjected to a cold- And a second step for forming the reverse gradient spur gear.

The inverse-graded forging device of an integrated dog clutch according to the present invention includes a lower mold (00) and an upper mold (200).

The lower mold 100 includes a lower body 101 on which a seat 102 is formed and a lower body 101 on which upper and lower ends of the spur gear of the dock clutch 10, To form a reverse gradient so as to form a reverse gradient spur gear.

5 is a view for explaining a shape of a backward gradient forming part 300 of a backward graded forging device according to the present invention. The backward projecting part 300 includes a lower body 101 of the lower mold 100, And a plurality of taper pins 310 radially disposed on the upper portion and movable forward toward the center direction.

The dog clutch 10 is positioned in the seating groove 102 of the lower body 101 in a state where the body of the speed gear 20 of the integrated dog clutch 10 is supported on the upper surface of the backlash- When the taper pin 310 is advanced in the lower portion of the body of the speed gear 20 supported while being pressed in the horizontal direction, each taper pin 310 is engaged with the respective straight type teeth 113 of the spur gear of the dog clutch 30, So that each value of the spur gear is reverse-gradient-formed.

The taper pin 310 is disposed to correspond to a position between the teeth of the spur gear 110 of the dog clutch 30. The tip 311 is trapezoidal in shape as it goes downward, The spur gear 110 is inserted between the teeth of the spur gear 110 so as to press the side surface of the teeth 113 of the spur gear 110 so that the teeth 113 of the spur gear 110 are formed unstably. The rear end of the taper pin 310 is in contact with the inner surface of the upper punch 210 when the upper punch 210 of the upper mold 200 descends, And has an inclined surface 312 that is inclined outward toward the downward direction so as to be movable.

The upper mold 200 includes an upper body 201 and an upper punch 210 for contacting the inclined surface 312 of the taper pin 310 when the lower body 200 is lowered to provide a pressing force to move the taper pin 310 in the horizontal direction And a stationary punch 220 for allowing the lower part of the preform to be uniformly placed on the taper pin 310 to maintain the stability of the preform.

The upper punch 210 is connected to the punch 220 disposed at the center of the upper body 201 and has a side end extending in an annular shape so as to surround the unfolded shape 300, The inner side surface contacts the slant surface 312 of the taper pin 310 to move the taper pin 310 in the horizontal direction.

The punch (220) allows the lower portion of the preform to be placed on the taper pin (310) to be uniformly positioned on the taper pin (310), thereby maintaining the stability of the preform.

To this end, as shown in FIG. 6, the stationary punch 220 according to the present invention includes at least three ejectors 221 having the same area so as to apply a uniform pressure to the preform.

A gas spring 222 is installed on the ejector 221 so as to be symmetrical with respect to each other. The reason why the number of ejectors 221 is limited to at least three is that it is difficult to maintain the stability of the preform when the number of ejectors 221 is less than three. However, the present invention is not limited to this, and the number of the ejectors may be changed.

The gas spring 222 is an elastic means configured to apply an elastic force to the preform in response to the lowering of the ejector 221. The gas spring 222 compresses nitrogen gas through a charging valve A cylinder having a gas chamber, a head accommodated in the gas chamber, and a rod connected to the cylinder.

When the force exerted on the rod from the outside is greater than the gas repulsion force exerted on the head, the gas is compressed and the rod is flexibly moved and the force applied to the rod is buffered.

The gas spring 222 is installed in the divided ejector 221 to buffer the pressing force applied to the ejector 221 to maintain the stability of the preform.

The gas spring 222 is installed inside and the elastic pressure of the ejector 221 divided into at least three portions is continuously applied to the position of the preform corresponding to the divided region when the elastic pressure of the ejector 221 is applied to the preform on the taper pin 310 So that the preform and the taper pin 310 are held in a fixed position.

Therefore, since the precise molding of the taper pin 310 for forming the reverse gradient in each tooth of the spur gear is implemented, it is not necessary to perform additional correction work for reducing the height deviation of the preform, Time can be reduced.

The ejector 221 of the punch 220 for pressing the preform thus disperses the load acting on the preform so as to apply a resilient and uniform pressure to the entire preform so that the preform It is possible to compensate for errors in lifting of the preform due to the offset of the uniform distribution load.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It should be understood that various modifications made by the person skilled in the art are also within the scope of protection of the present invention.

10: Integrated dog clutch 20: Speed gear body
30: dog clutch 100: lower mold
101: lower body 102: seat groove
200: Upper mold 210: Upper punch
220: Political punch 221: Ejector
222: gas spring 300: reverse gradient forming part
310: Taper pin

Claims

And a reverse gradient forming unit provided on an upper portion of the lower body to form a reverse gradient in each tooth of the spur gear of the dock clutch to form a reverse gradient spur gear; And the upper mold is provided with an upper punch for providing a pressing force so that the preform is uniformly positioned on the taper pin when a reverse gradient is formed on each tooth of the spur gear, In a punch for a stationary graded forging apparatus for stabilizing stability,
The punch for fixing,
An ejector having the same area and divided into at least three sections so as to uniformly maintain a total distribution load of the preform while uniformly applying a pressure to the entire preform while dispersing a load acting on the preform; And
And a gas spring made of a nitrogen spring for buffering a pressing force applied to the ejector so as to apply an elastic force to the preform and installed in the ejector so as to maintain the stability of the valve. .

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