JPH0649389Y2 - Die for forging joining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a mold used when two types of materials having different rigidity are put into a mold and joined by forging.

[Conventional technology]

Conventionally, forging joining, in which two materials having extremely different rigidity are wrapped by joining one material with the other material, and joined, when forming with a forging pressure higher than the plastic deformation stress of the highly rigid material, the other one has low rigidity. This was extremely difficult because the material could not withstand this pressure and broke.

For this reason, two kinds of materials having different rigidity are joined by pasting, but the joining strength is low and the durability and reliability are also low.

JP-A-62-168 discloses a method for improving the conventional joining forging method.
In 625 publication, when the SiC whisker reinforced composite material is embedded in a base metal such as iron or stainless steel, the base metal and the molded SiC whisker reinforced composite material are heated to 450 to 550 ° C. and forged under pressure. A method has been proposed in which the head is preheated to 200 to 400 ° C. and the forging pressure head is pressure forged at a pressure of 1000 to 3000 Kg / cm ² .

[Problems to be solved by the device]

In the forge joining method described in the publication, the heating temperature of the forging material and the forging pressure head must be strictly controlled,
The forging temperature fluctuates and abnormal stress occurs in the low-rigidity material, causing it to break. Further, when the weight of the forged material varies, the destruction also occurs.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a die for forging joining in which low stress does not occur in a low-rigidity material.

[Means and Actions for Solving the Problems]

According to the present invention, in a mold in which two kinds of materials having different rigidity are put into a mold and molded and bonded by forging, the part of the mold that presses the bonding surface of the two kinds of materials is operated with a predetermined allowable stress or more. It is a movable die for forging and joining.

When two types of materials having different rigidity are put in a die and pressure is applied by hot forging, the highly rigid material is plastically deformed and molded, and is simultaneously joined.

If the heating temperature or volume of the high-rigidity material varies, a huge impact load may be momentarily applied, and one of the low-rigidity materials may be destroyed. The fracture of the low-rigidity material is a fracture due to the compression force during the forging process.

Since the part of the mold that presses the joining piece of the two materials is configured as a movable mold, when a huge impact load is momentarily applied, the movable mold releases the compressive stress in this part,
Compressive stress above the allowable stress set for the movable type is not applied to the joint, and destruction of the low-rigidity material is prevented.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment in which the present invention is applied to a rocker arm forging die of an engine, in which a forging material is placed on a fixed lower die 1 and an upper die 2 is moved up and down for forging.

The work W, which is a rocker arm forming material to be inserted into the mold, has a base material made of steel, which is a high-rigidity material. It is joined by forging. The upper die 2 is provided with a through hole 3 in a region on the back side of the joining piece Wa which presses the work W, and a movable die 4 sliding in the through hole 3 is arranged with a spring 5 loaded. The strength of the spring 5 is set so that the spring 5 operates above the allowable cold compressive stress of the joining piece Wa which is a low-rigidity material. 6 is a spring bridge.

Next, forging using this forging joining die will be described.

The work W and the preformed joining piece Wa are placed on the lower die 1, the upper die 2 is lowered and pressure is applied to the workpiece W, and the work W is plastically deformed and shaped. The formed back surfaces are joined. Generally, in the case of hot forging, the plastic deformation stress of the base steel is significantly smaller than the cold compressive stress of the joining piece Wa of the low rigidity material of the ceramic material, so that the back surface of the joining piece Wa is The steel plastically flows around the irregularities and the two are firmly joined.

If the heating temperature or volume of the work W, which is a high-rigidity material, is varied, a huge impact load is momentarily applied to the cold-joined low-rigidity material piece Wa, and the piece Wa is destroyed. There is. The fracture of the joining piece Wa of the low-rigidity material is a fracture due to the compressive force during the forging process.

Since the movable die 4 is arranged on the upper die 2 at a portion for pressing the work W on the back side of the joining piece Wa by loading the spring 5, when a huge impact load is momentarily applied to the joining piece Wa. Moreover, the movable die 4 pushes up the spring 5 to release the compressive stress in this portion, and the compressive stress exceeding the allowable stress set by the spring 5 is not applied to the joining piece Wa, and the joining piece Wa is prevented from being broken.

In the above embodiments, the movable die 4 is provided in the upper die 2, but it can be provided in the lower die, and it goes without saying that a fluid shock absorber can be applied instead of the spring.

As a low-rigidity material, in addition to ceramics, aluminum,
Copper, magnesium, etc. can be used, and high rigidity materials such as carbon steel and chrome molybdenum steel can be forged and joined.

In addition to the rocker arm of the engine shown in the embodiment, for the purpose of improving partial rigidity or wear resistance of the valve, the valve seat, the cam nose of the camshaft, the journal part of the bearing, the pin part of the connecting rod cap, etc. 2 It can also be applied to a member for joining seed materials.

[Effect of device]

In the present invention, when the forging pressure applied to the low-rigidity material exceeds a predetermined value, the stress of the joint part, which is a part of the mold, is released, so that the heating temperature and volume of the high-rigidity material are increased. Even if there is a variation, it is possible to prevent the low-rigidity material from being damaged and to obtain a strong joint strength between the low-rigidity material and the high-rigidity material.

[Brief description of drawings]

 FIG. 1 is a sectional view showing an embodiment of the present invention. 1: Lower die, 2: Upper die 3: Through hole, 4: Movable die 5: Spring W: Work piece of high rigidity material Wa: Joint piece of low rigidity material

Claims (1)

[Scope of utility model registration request] 1. A mold for molding and bonding two kinds of materials having different rigidity into a mold by forging and actuating a part of the mold which presses a bonding surface of the two kinds of materials at a predetermined allowable stress or more. A die for forging and joining which is characterized by being made movable.