JPH05349A - Forging device for crankshaft - Google Patents

Abstract

PURPOSE:To allow a hot forging work for a crankshaft by automatically transporting a crankshaft material by means of a transporting device. CONSTITUTION:The forging device of this invention is provided with a bending die 21, forging dies 34, 35, and a trimming die 24. The transporting means is provided with finger parts 33-36 by which the crankshaft material is held when the crankshaft material is raised from each die by a prescribed stroke. A knockout means having a holding part, by which a portion nearly rectangular in the cross section of the crankshaft material is held, is provided in the bending die; in the crankshaft material worked by the forging dies, a knockout means by which burrs integrated with are pressurized is provided in the forging dies; and in the trimming die, a knockout means holding a journal part is provided. Forging scratches are not caused on products, the yield of the products is improved, and the working rate of the forging work line is greatly improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crankshaft forging device for carrying out hot forging while automatically conveying a crankshaft material to forge the crankshaft.

[0002]

2. Description of the Related Art FIG. 9 is a diagram showing an example of a crankshaft S for an automobile. The illustrated crankshaft S is 4
Since it is used for a cylinder engine, five journal parts J are provided on the same axis with respect to the center of rotation, and four crank pins P to which the piston rod of the engine is mounted are provided. There is. Further, counterweights B are provided at four locations corresponding to the number of crankpins P.

A process of molding such a crankshaft S is shown in FIG. First, FIG.
A rod-shaped material W having a rectangular cross section as shown in FIG.
After heating a to a predetermined temperature equal to or higher than the recrystallization temperature, a reducing roll (not shown) is used to form a small diameter portion on both sides of the central portion of the material Wa as shown in FIG. A raw material, that is, a billet W is formed. As a result, as shown in FIG. 10 (B), the crankshaft material W in which the balance weight portion and the journal portion are volume-distributed is formed.

Then, the crankshaft S, which is a product, is formed on the crankshaft material W by the three forging steps shown in FIGS. 10 (C) to 10 (E).
All of these three steps are formed by die forging using a forging die. Of these steps, the first step of forging shown in FIG. 10 (C) is called a bending step, and is a step of forming the crankshaft material W so that the center of the crankshaft material W is offset according to the shape of the counterweight B of the product. Is. The second step of forging shown in FIG. 10D is a step of rough forming using a forging die for rough forming which is also called a block die or a rough die, and in this step, the crankshaft material W is A part of it flows out from the flash land of the mold, and a burr (flash) F is formed. Further, FIG. 10E shows a finishing process using a finishing forging die called a finishing die or a finish die, and the molding of the crankshaft S, which is a product, is completed. After finishing such a forging process, as shown in FIG.
In the trim step as shown in (F), the burr F portion is separated from the product S portion.

FIG. 11 is a view showing the conventional structure of the lower die of the forging dies constituting the three steps shown in FIGS. 10 (C) to 10 (E). Forging die 12 and finishing forging die 1
3 are arranged and integrated in this order, and a recess corresponding to the shape to be processed is formed in each mold. However, the forging die shown in the figure shows only the lower die, and the upper die having the recessed portion is the lower die 11 to 13 like the lower die.
It can be moved up and down.

[0006]

Conventionally, when a crankshaft S, which is a product, is formed by using such a forging device, all the positioning with respect to the three forging dies shown in FIG. 11 is performed by the operator. It is done by hand.
Therefore, the worker first places the crankshaft material W processed into the shape shown in FIG. 10B on the bending die 11 by manual work, and further manually after the processing process is completed. It is necessary to mount the bending die 11 on the forging die 12 for rough forming. The same applies to the case where the forging die 12 is placed on the finishing forging die 13. However, since the crankshaft material W easily sticks to the two dies 12 and 13, the burrs A knockout pin 14 for pressing the F portion is provided. Therefore, the worker manually conveys the crankshaft material W lifted by the knockout pin 14 to the next step.

However, in the forging process using such a conventional crankshaft forging device, an operator manually positions the crankshaft material W on each die, and therefore, the accuracy is accurate. However, if an unskilled person performs the forging work, the crankshaft material W and the dies 11 to 13 may be misaligned, which may cause forging scratches on the product.
In addition, various attempts have been made to automate the forging process.However, if such a forging device is applied to an automatic press, the crankshaft material can be transferred in the same manner as when the crankshaft material is transferred by a transfer device or a manipulator. The transfer device may cause a misalignment at the time of setting, resulting in a clamp error, and further, forging flaws may occur in the product and the defective rate may increase, resulting in a decrease in the operating rate of the entire forging line. Was to be invited. Therefore, the present invention improves the forging die to automatically convey the crankshaft material,
The purpose is to enable hot forging of the crankshaft.

[0008]

The present invention for achieving the above object provides a crankshaft forging apparatus for forging a crankshaft material, which is capacity-distributed to a balance weight portion and a journal portion, in a heated state. Bending dies that process crankshaft material by the cooperation of upper and lower dies, forging dies, and trimming dies are continuously arranged at predetermined intervals, and the cross-sectional shape of the crankshaft material of the bending dies is A knockout means having a holding portion for holding the rectangular portion is provided so as to be capable of rising in a portion substantially corresponding to the rectangular portion, and a knockout for pressing the burr to a portion corresponding to the burr formed after the forging die is processed. Means is provided so that it can be raised, and the journal portion is provided at a portion corresponding to the crankshaft journal portion of the trimming die. Knockout means having a journal holding portion for holding is provided so as to be able to rise, and when the crankshaft material is raised by each of the knockout means, a finger portion formed according to the shape of the crankshaft material is engaged with each crankshaft material. After combining
The crankshaft forging device is characterized in that a conveying means for moving to a next step is mounted along each of the molds.

[0009]

In the forging device having the above structure, the crankshaft material is sequentially conveyed by the conveying means to each die. During transportation, the crankshaft material is gripped by the fingers provided on the transportation means, and the gripping by the fingers holds the portion of the crankshaft material having a substantially rectangular cross section in the bending die. The forging die for rough forming and the forging die for finishing are made in a state of being held by a knockout means having a holding portion that uses a knockout pin that presses the burr portion formed on the crankshaft material. The crankshaft material is held, and in the trimming die, the crankshaft material is held by the knockout pin at the journal portion. As a result, the crankshaft material is accurately positioned at a predetermined position with respect to each mold, and the crankshaft material that has been processed in each mold is reliably gripped and conveyed to the next processing step.

[0010]

FIG. 1 is an overall view showing a crankshaft forging device according to an embodiment of the present invention. A bending die 21, a roughing forging die 22, and a finishing forging die. The mold 23 and the trimming mold 24 are arranged adjacent to each other. These molds 21
Reference numerals 24 to 24 are lower molds, and upper molds (not shown) are movable above and below the lower molds 21 to 24.

As shown in FIG. 1, two three-dimensional transfer feeders 31 and 32 are mounted on both sides of these molds. Each transfer feeder 3
1 and 32 are adapted to move closer to each other, move upward, move forward, move downward, move away from each other, and move backward. The feeders 31 and 32 correspond to the molds 21 to 24, respectively. 33 to 36 are attached.

The detailed shapes of the molds 21 to 24 shown in FIG. 1 are as shown in FIG. 2, and the crankshaft material W formed into a shape shown in FIG. The bending die 21 is provided with two knockout pins 41 so as to be vertically movable. These knockout pins 41 are included in the crankshaft material W which is heated by being volume-distributed to the balance weight part and the journal part by the reduction process.
In order to hold a portion having a substantially rectangular cross section, as shown in FIG. 3, a holding portion having a bottom surface 42a and side surfaces 42b parallel to each other and having a substantially U-shaped cross section. Four
Have three. The knockout pins 41 described above are vertically moved by hydraulic cylinders (not shown). The crankshaft material W after being processed by the reduce roll is conveyed to the vicinity of the die shown in FIG. 1 and transferred to the transfer feeder 3 shown in FIG.
It is placed on the bending die 21 by the Nos. 1 and 32, but at this time, as shown in FIG. 3 (A), the holding portion 43 is at the lower limit. Therefore, during this mounting operation, the side surface of the crankshaft material W is guided by the side surface 42b of the holding portion 43 and is accurately set in a predetermined posture. Then, after being set, the upper mold (not shown) is moved downward, and the crankshaft material W is bent in cooperation with the lower mold 21.

In the process of this processing, a portion having a rectangular cross section remains in the crankshaft material W corresponding to the shape of the holding portion 43 in the crankshaft material W. Therefore, when the knockout pin 41 is raised, the crankshaft material W
Is lifted while being held by the holding portion 43 of the knockout pin 41. Under this state, the transfer feeders 31 and 32 shown in FIG.
The crankshaft material W is clamped by the finger portions 33 provided at 32 and is conveyed to above the forging die 22 for rough forming. As described above, the holding portion 43 of the knockout pin 41 provided in the bending die 21 does not hold the vicinity of the rotation center where the crankshaft material W has a circular cross section as shown in FIG. The rectangular part is retained. As a result, the crankshaft material W is held in the holding portion 4.
3 is securely held without rotating when it is mounted on No. 3 and when it is moved up by the knockout pin 41.

In the conventional forging die 22 for rough forming, which is also called a rough die, a journaled portion having a size corresponding to the final shape of the journal portion J of the product S is conventionally formed. The die 22 has a size corresponding to the outer diameter of the journal portion of the crankshaft material W for which the bending process has been completed. That is, FIG.
The outer diameter of the journal portion J of the final product S shown in 0 (F) is D, and the outer diameter corresponding to the journal portion J of the crankshaft material W after the bending process is Da as shown in FIG. Then, the value of Da is 20% than D
It is a value that has increased to some extent, and this forging mold 2
Of the two, the part Ja that processes the journal part J is Da
The diameter is set to correspond to. As a result, the crankshaft material W is better seated with respect to the forging die 22, and at the same time, when the crankshaft material W is unclamped on the forging die 22, the crankshaft material W slightly moves. Although it will fall, it helps to accurately position the crankshaft material W in the longitudinal direction and the conveying direction. To remove the crankshaft material W after rough forming,
The knockout pin 51 pushes up the portion of the burr F formed by this processing. Knockout pin 5 with the same structure is used for finishing forging die 23.
1, the crankshaft material W is taken out.
Therefore, since the crankshaft material W is held by the knockout pin 51 at the burr B, the crankshaft material W is securely held without rotating.

FIG. 5 is a cross-sectional view showing a state in which the crankshaft material W is placed on the forging die 22 for rough forming. In the die 22 of the present invention, the counterweight B is not shown. The die height of the portion Ba to be formed and the portion Wb to form the portion of the web on the opposite side to this are carved lower than before. Conventionally, the height is the same as that of the flash land L, but the height is formed so as to prevent the crankshaft material W from rotating when the crankshaft material W is placed on the die 22. This is because.

Both forging dies 22 and 23 are
As shown in FIG. 2, the flash lands L are formed to extend in the longitudinal direction from both ends of the crankshaft material. This is because if the burr F becomes thick, bends, or becomes long enough to pop out of the mold 22, the crankshaft material W cannot be gripped by the fingers 34 and 35 of the transfer bars 31 and 32.
This is to make the burr F thin and straight, and to prevent the burr F from becoming too long in the longitudinal direction.

FIG. 6A shows a forging die 2 for rough forming.
Crankshaft material W in the state where processing is completed by 2
It is a figure which shows, and a part of crankshaft raw material W comes out from the land part L of this forging die 22, and the burr F is formed. After the processing is completed, the burr F is used to lift the crankshaft material W by the knockout pin 51 as shown in FIG. 6B. The crankshaft material W in the lifted state is gripped by the fingers 34, and the forging die 2 for the next finish is formed.
3 is conveyed to the top. In this way, the crankshaft material W is conveyed from the forging die 22 for rough forming to the forging die 23 for finishing using the both ends of the burr F in the longitudinal direction while being grasped by the fingers 34. Then, it is conveyed from the forging 23 to the trimming die 24 while being held by the fingers 35.

FIG. 7 is a view showing a trimming die 24. The trimming die 24 has a receiving die 24a which is a main body of the die, and a crankshaft formed above the receiving die 24a by the receiving die 24a. Material W
An upper die having a top stripper 61 for holding and a trim die 62 for removing the burr F is vertically movable by a ram (not shown). To cut off the burr F, first, after holding the crankshaft material W by the receiving die 24a and the top stripper 61, the trim die 62 moves downward to separate the burr F from the crankshaft material W. This receiving die 2
4a, as shown in FIG. 2, a journal holding portion 63 for holding the journal portion J of the crankshaft material W.
Is provided. Thus, in the trimming die 24, the journal portion J, which is the rotation center of the crankshaft material W, is held, and the product S after the burr B is removed is kept in rotational balance. ,
The product S is securely held without rotating.

FIG. 8 is a view showing details of the knockout pin 64 having the journal holding portion 63. The knockout pin 64 is movable up and down by a hydraulic cylinder (not shown), and the journal holding portion 63 is provided with a guide rod 6 for the receiving die, that is, the trimming die 24.
It is supported by 5 so as to be vertically movable. Reference numeral 66 is a coil spring for urging a downward elastic force to the journal holding portion 63, and reference numeral 67 is a bottom stripper.

Although the drawings show a crankshaft for a four cylinder engine, the invention is applicable to various types of crankshafts.

[0021]

As described above, according to the present invention, when the crankshaft is forged by the forging device having the bending die, the forging die and the trimming die, the die is provided for each die. Since the crankshaft material is delivered at the position lifted from the mold by the knockout pin, it becomes possible to automatically convey the crankshaft material by the conveying means having the finger portions for gripping the crankshaft material, and efficiently. It has become possible to forge the crankshaft with high yield. As a result, the operability of the forging line was greatly improved and the occurrence of defective products was reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire hot forging press die of the present invention and a conveying device for sequentially conveying a crankshaft material to the die.

2 is a perspective view showing a part of the mold shown in FIG. 1,

FIG. 3 (A) is a sectional view of the bending mold showing a state where the knockout provided in the bending mold is at the lower limit position, and FIG. 3 (B) is a knockout of the crankshaft material after the bending process. A sectional view of a bending die showing a state of being raised by a pin,

4 (A) is a front view showing a crankshaft material after being processed by a reduce roll, FIG. 4 (B) is an end view taken along line BB of FIG. 4 (A), and FIG. 4 (C) is Same figure (A)
End view of CC line of

FIG. 5 is a sectional view showing a state in which a crankshaft material is placed on a forging die for rough forming.

6A is a cross-sectional view showing a rough forming forging die showing a state where rough forming is completed, and FIG. 6B is a crankshaft material after the rough forming is completed and is lifted by a knockout pin. Sectional view showing the state,

FIG. 7 is a perspective view showing details of a trimming die,

FIG. 8 is a sectional view showing details of a knockout pin provided on a trimming die,

FIG. 9 is a perspective view showing an example of a crankshaft,

10A to 10F are process diagrams showing a hot working process of a crankshaft,

FIG. 11 is a perspective view showing a conventional hot working die.

[Explanation of symbols]

21 ... Bending die, 22 ... Rough forming forging die, 23 ... Finishing forging die, 24 ... Trimming die, 31, 32 ... Transfer feeder (conveying means), 33-36 ... Finger part , 41 ... Knockout pin, 43 ... Holding part, 51 ... Knocking pin,
63 ... Holding part, 64 ... Knockout pin, F ... Burr, J
… Journal section, S… Crankshaft.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hisao Suzuki 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Yoshimi Yamauchi 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. ( 72) Inventor Ryo Watari Yamada 5-2 Sokai-cho, Niihama-shi, Ehime Sumitomo Heavy Industries Machinery Co., Ltd. Niihama Factory (72) Inventor Yutaka Ozaki 5-2 Sokai-cho, Niihama-shi, Niihama Niihama Industrial Co., Ltd. Inside the factory

Claims (1)

Claim: What is claimed is: 1. A crankshaft forging apparatus for forging a crankshaft material, which has a volume distribution between a balance weight portion and a journal portion, in a heated state. A bending die for processing the material, a forging die, and a trimming die are continuously arranged at predetermined intervals, and the crankshaft material of the bending die has a cross-sectional shape corresponding to a substantially rectangular portion. A knockout means having a holding portion for holding the rectangular portion is provided so as to be able to rise, and a knockout means for pressing the burr is provided at a portion corresponding to the burr formed after processing the forging die so that the trimming is possible. A journal holding part that holds the journal part is provided at the part corresponding to the crankshaft journal part of the mold. Provided to be raised knockout means that the when the crankshaft blank is raised by the knock-out means, after a finger portion formed according to the shape of the crankshaft material was engaged with each crankshaft blank,
A crankshaft forging device, characterized in that a conveying means for moving to a next step is mounted along the respective molds.