JPS6178528A - Forging forming method of connecting rod cap - Google Patents

Abstract

PURPOSE:To miniaturize, etc. a forging machine by squashing a cylindrical blank material in a flat square shape and by forming the medium formed article providing two pieces in parallel with performing a closed forging. CONSTITUTION:A rising part R is formed in four places with upsetting a cylindrical blank material W in a flat shape. The blank material W is then enclosed in the closed space formed by a punch and die and is further squashed to a flat square shape, also a preparatory forming is performed upto the prescribed shape of curvature by a closed forging. The blank material W being formed preparatorily is in succession subjected to a finishing formation with the closed forging of the punch and die and the medium formed product P having the shape of two pieces of the final products being provided in parallel is obtd. With the division and trimming of said medium formed product, two pieces of the final products are obtd. simultaneously. Due to the blank material W being enabled to be formed in a flat square shape with said method, the size of a forging machine is miniaturized and the productivity is improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forging a connecting rod cap for an internal combustion engine.

BACKGROUND OF THE INVENTION As a method for forging a gap (bearing cap) attached to the large end of a connecting rod of an internal combustion engine, there is a so-called multi-cavity forging method.

Figures 5 and 6 show an example 7 in which processing is performed using a vertical forging press, in which a long material W is supplied between the upper die 1 and the lower die 2 and press-formed. As shown in the figure, an intermediate molded product P is obtained in which, for example, two connecting rod caps are arranged side by side in the longitudinal direction. Then, in the post-process, the entire interior of beam B etc. 2)
By pressing IJ, two connecting rod caps, which are molded products, are simultaneously molded.

Problems to be Solved by the Invention When attempting to forge using a high-speed multi-stage forging machine with excellent processing efficiency based on the above-mentioned multi-piece forging method,
A characteristic of high-speed multi-stage forging machines is that the orientation of the material when it is shear cut in the front stage of the forging machine does not match the orientation of the material required by the die, so the material is It is necessary to change the posture by at least 90 degrees.

In addition, as shown in Fig. 5, an intermediate molded product P of horizontal series type
In order to obtain this, the material would be too long, and the forging machine itself would require a lot of work.

It is an object of the present invention to provide a method that makes it possible to forge a plurality of connecting rod caps without incurring the above-mentioned material reversal operation or increasing the size of the forging machine. It is.

Means for Solving the Problems In the present invention, two connecting rod caps are formed by crushing a cylindrical material into a substantially oblate shape (upsetting) and sealingly forging the substantially oblate material. The method includes the steps of molding intermediate molded products arranged in parallel shapes, and cutting the intermediate molded products into 2-ill connecting rod caps.

In this case, a preforming step may be added before the step of molding the intermediate molded product. In addition, since the intermediate molded product has a shape in which two connecting rod caps are arranged side by side in the wall thickness direction, there is an excess thickness in the continuous part.
This excess thickness is trimmed when the two connecting rod caps are separated.

According to the present invention, when forging with a high-speed multi-stage forging machine, (
・Although it is a so-called two-piece structure, the length of the material is longer.
・This eliminates the need to increase the size of the forging machine, and also eliminates the need for reversing the material.

EXAMPLE FIG. 1 (5) to (1) are process explanatory diagrams showing an example of the method of the present invention.

In the crushing process of the gt process shown in Fig. g1 (Bl), the cylindrical material W (Fig. 2 (A)
))' to flatten it (upset).

At this time, considering the free flow of the material W in the subsequent process, raised portions R are formed at four locations as shown in FIG. 2 (Bl).

In the second preforming process shown in Figure 1 (q), the material W
' is further crushed into an oblate shape and preformed into a shape with a predetermined curvature as shown in Figure 2 (Q).The specific method for this preforming process is as shown in Figure 3. A closed forging method is used in which the material W is sealed and pressurized in a closed space defined by a punch 3 and a die 4.

In the third finish forming step shown in FIG. 1(D), the preformed material W is finish formed to create an intermediate molded product P that is faithful to the final product shape. As shown in the figure, the intermediate molded product P has a shape in which two connecting rod caps, which are the final molded products, are arranged side by side in the thickness direction.

In addition, as a specific method in this finish forming process, the fourth
As shown in the figure, a closed forging method is used in which the material Wf is enclosed and pressurized in a closed space defined by a punch 5 and a die 6.

Subsequently, in the final trimming step shown in FIG. 1(E), the intermediate molded product P11 is sheared and divided into 3 blocks, and the surplus portion B generated in the continuous portion is trimmed. As a result, two connecting rod caps CI and C2, which are molded products, are obtained at the same time.

Effects of the Invention As described above, according to the method of the present invention, closed forging with a so-called 2 (l! cut) can be performed using a high-speed multi-stage forging machine without reversing the material 90 degrees, and the material can be forged in almost any direction. Since the shape is pressed and pressed, the material does not become extremely long in the horizontal direction as in the past, and the forging machine does not need to be large.

[Brief explanation of drawings]

The first prisoner, @, (Q, (D), C-th is a process explanatory diagram showing an embodiment of the present invention, the second position is a front view of the first prisoner, and the second figure (B) is the first figure (Cross-sectional view of Bl along line I[-II, Figure 2 (q is a front view of Figure 1 (front view of Q, Figure 2 (D
1 is a front view of Dl, FIG. 3 is a cross-sectional view showing the mold configuration of q, FIG. 4 is a cross-sectional view of the mold configuration of Dl, and FIG. 5 is a conventional Fig. 6 is a sectional view of the bath 5 taken along the line VI-VI in Fig. 5. W...Material, P...Intermediate molded product, C+, Cz...・Connecting rod cap. 1. 2. Heat (D)

Claims (1)

[Claims] (1) A method for simultaneously forging two connecting gland caps, which are molded products, and includes a process of crushing a cylindrical material into a substantially oblate shape, and a process of sealingly forging the substantially oblate material. , comprising the steps of molding an intermediate molded product having a shape in which two connecting rod caps are arranged side by side, and separating the intermediate molded product into two connecting rod caps. A forging method for connecting rod caps.