JPH03230837A - Punch supporting structure for closed forging die set - Google Patents

Abstract

PURPOSE:To prolong the lives of a punch and a punch supporting surface by bringing a surface to be supported of the punch and a punch supporting surface of a punch supporting member into a spherical contact with each other. CONSTITUTION:When a billet W1 is loaded in a closed space formed by a lower die 66 and an upper die 67 and the punch supporting members and punches 1, 2 are approached to one another to pressurize the billet W1, a forged part of a prescribed shape can be obtained. At this time, large surface pressures act on the contact surfaces 3a, 4a between the punches 1, 2 and the punch supporting members but since the surfaces 5a, 6a to be supported by the punches and the punch supporting surfaces 3a, 4a of the punch supporting members are brought into contact with each other through the spherical surface though nonconformity such as fine inclinations or unbalanced loads is generated in the punches 1, 2, the surface pressures are actuated uniformly. Consequently, the surfaces to be supported by the punches and the punch supporting surfaces of the punch supporting members reduce in wear and the punches and the punch supporting members are prolonged in life, therefore, the maintenance cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a punch support structure for a closed forging tool set.

<Prior Art> FIG. 2 is a vertical cross-sectional view showing an example of a conventional closed forging die set, and FIG. 3 is an enlarged view of the main parts at the bottom dead center of the press in FIG. 2.

As shown in FIGS. 2 and 3, a fixed die 63 is attached to the fixed base 61, and a lower mold 66 is attached to the fixed die 63. Further, a piston 53 is installed inside the stationary die 63, and a punch supporting oil chamber 63a and a pull pack oil chamber 63b are defined.

A lower punch 51 that slides within a lower mold 66 is fixed to the upper part of the piston 53 by a holding plate 68 and bolts 69.

A movable die 64 is attached to the slide 62, and an outer piston 65 and an inch piston 54 are installed inside the movable die 64, and a primary oil chamber 64a and a punch supporting oil chamber 6 are installed.
A 4b1 pull pack oil chamber 64c is defined.

An upper mold 67 is attached to the lower part of the outer piston 65,
An upper punch 52 that slides within the upper mold 67 is fixedly provided at the lower part of the inner piston 54 in the same way as the lower punch 51 .

Primary oil chamber 64a and each punch support oil chamber 63a, 6
4b, a hydraulic pressure generator 71 is connected via a relief valve 73 and a check valve 72. Also, a pull pack oil chamber 63b.

An accumulator 75 is connected to 64c.

As shown in FIG. 2, when the material W is loaded into the lower mold 66 and the slide 62 is lowered, and the upper mold 67 comes into contact with the lower mold 66, the outer piston 65 stops, but the movable die 64 continues to move above and below the bottom dead center, and the primary oil chamber 64a is compressed.

The pressure generated by this compression expands the upper and lower punch support oil chambers 63a, 64b, and as shown in FIG. W is pressurized to form a finished product W1.

Then, before reaching the bottom dead center, the finished product W is placed in the closed space.
1, each punch = 3 51.52, piston 53, and inner piston 54 stop, but the movable die 64 descends, so the primary oil chamber 64
The pressure in the oil chambers 63a and 64a for supporting the punch increases extremely, and when the pressure exceeds the allowable pressure, the oil pressure is relieved from the relief valve 73.

When the slide 62 passes the bottom dead center, the movable die 64 rises, so the primary oil chamber 64. The pressure in the punch support oil chambers 63a and 64b decreases, and the accumulator 75
The pull-pack hydraulic pressure moves the piston 53 and the inner piston 54 to their original positions, and the outer piston 65 also moves to its original position. Further, when hydraulic pressure is relieved from the relief valve 73, the insufficient hydraulic pressure is replenished by the pressure generating device 71.

<Problems to be Solved by the Invention> By the way, in such die sets for closed forging, there are many cases in which the punch causes a slight inclination or is subjected to an uneven load due to manufacturing errors, etc.4.

However, if the conventional punch has the above-mentioned problem, the support surface is flat, and the local surface pressure on the support surface becomes extremely large, causing chipping and uneven wear.

As a result, the lifespan of the punch and the punch support member is shortened, which increases maintenance costs, increases downtime of the apparatus due to replacement of the punch and the punch support member, and reduces productivity.

Means for solving the problems mentioned above II! The structure of the present invention to solve problem I is a closed forging method in which a fixed die is attached to the fixed base of a reciprocating press, a movable die is attached to the same slide, and a die and a punch are attached to both dies. The die set is characterized in that the punch is provided with a spherical supported surface, and the punch support member of the die set is provided with a concave spherical punch support surface that substantially coincides with the supported surface of the punch. shall be.

Function: Load the material into the closed space formed by the lower mold and upper mold,
By bringing the upper and lower punch support members and the punch close to each other and pressurizing the material, a forged product having a predetermined shape can be obtained.

At this time, a large surface pressure acts on the contact surface between the punch and the punch support member, but even if there is a problem such as a slight inclination of the punch or an unbalanced load, the supported surface of the punch and the punch support member Since the punch support surface and the punch support surface are in spherical contact with each other, the surface pressure acts equally.

Embodiment Hereinafter, an embodiment of the present invention will be explained in detail with reference to the drawings, and the same members and parts as the conventional device are designated by the same reference numerals.
Omit duplicate explanations.

In FIG. 1, a concave spherical punch support surface 3a is formed at the upper end of a piston 3 serving as a punch support member. This punch support surface 3a has a spherical supported surface 5a.
The lower punch 1 is attached to the presser plate 68 via the spherical block 5 on which the spherical supported surface 5a is formed.
and bolts 69, and the tip of the lower punch 1 is slidably inserted into the lower mold 66.

Similarly, a concave spherical punch support surface 4a is formed at the lower end of the inner bis 4 as a punch support member. This punch support surface 4a has a spherical supported surface 6a.
The upper punch 2 is fixed by a presser plate 68 and bolts 69 via the spherical block 6 having a spherical block 6 formed therein, and the tip of the upper punch 2 is slidably inserted into the upper mold 67.

Note that portions of the piston 3 and the inner piston 4 that are not shown have the same shape as the piston 53 and the inner piston 54 of the conventional device, and are engaged in the same manner as other members.

When the die set shown in FIG. 1 is operated in the same manner as the conventional device, the movable die 64 descends until the press reaches the bottom dead center, and rises until the lower punch 1 and the closed space formed are filled with the product W1. Then, it descends and pressurizes the finished product W1 to form it into the desired shape.

At this time, the lower surface of the lower punch 1 and the upper surface of the spherical block 5,
Although a large load acts on the punch supporting surface 3a and supported surface 5a, the upper surface of the upper punch 2 and the lower surface of the spherical block 6, and the punch supporting surface 4a and supported surface 6a, each of the punches 1 and 2
If the axes of the piston 3 and the inner piston 4 do not match, at the same time as the load starts to act on their respective contact surfaces,
The supported surfaces 5a, 6a of the spherical blocks 5, 6 slightly slide on the punch support surfaces 3a, 4a to support the upper and lower punches 1, 2.
The contact between the block and the spherical blocks 5 and 6 is corrected, and the load is evenly distributed. Note that the punch support surface 3a.

Needless to say, the contact between the support surface 4a and the supported surfaces 5a and 6a is always good.

The present invention is not limited to the above-mentioned embodiments. For example, in this embodiment, the punch with high wear rate and the supported surface which is expensive to process are separated by a spherical protrusion. The punch and the spherical block may be integrated as long as the degree of wear and tear is low.

<Effects of the Invention> As explained in detail above, in the present invention, by bringing the supported surface of the punch and the punch supporting surface of the punch supporting member into spherical contact with each other, the contact surface is When a large load is applied to the punch, for example, even if the axes of the punch and the punch support member do not match, the contact surface is spherical, so the surface pressure acts evenly, and the load is evenly supported. be done.

Therefore, wear of the supported surface of the punch and the punch supporting surface of the punch supporting member is reduced, and the life of the punch and the punch supporting member is extended, so that maintenance costs thereof can be reduced.

In addition, there is less need to replace punches and punch support members, which reduces device downtime and improves productivity.

and improve productivity.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a die set for closed forging as an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view showing an example of a conventional die set for closed forging, and FIG. FIG. 2 is an enlarged vertical cross-sectional view of the main part at the bottom dead center of the press in FIG. 2; In addition, in the drawings 1...Lower punch, 2...Upper punch, 3...Piston, 3a...Punch support surface, 4...Inner piston, 4a...Punch support surface, 5.6. ... Spherical block, 5a, 6a... Supported surface, 63... Fixed side die, 64... Movable side die, 65. Outer piston, 66... Lower mold, 67... Upper mold, Wl...It is a finished product.

Claims (1)

[Claims] In a die set for closed forging, in which a fixed die is attached to the fixed base of a reciprocating press, a movable die is attached to the same slide, and a die and a punch are attached to both dies, a spherical supported object is attached to the punch. Along with providing a surface,
A punch support structure for a die set for closed forging, characterized in that a punch support member of the die set is provided with a concave spherical punch support surface that substantially coincides with a supported surface of the punch.