JPS63171237A - Porging method - Google Patents

Abstract

PURPOSE:To form both ends of one set of products by one stroke of a punch and to improve productivity by pressing and molding one set of the rough materials disposed on both sides of an intermediate die in-between by means of a pair of the punches. CONSTITUTION:One set of the rough materials 8, 8 are put into the hole 3a of a die 3 in the state of sandwiching the intermediate die 6. The movable punch 4 is lowered and one set of the materials 8 are molded to pistons 1, 2, etc., of a prescribed shape by the stationary punch 5 and the die 6. The movable punch 4 is risen and the pistons 1, 2 and die 6 left in the hole 3a of the die 3 are pushed upward and discharged by the actuation of a sleeve knock- out. Two pieces of the pistons 1, 2 and recesses in peak parts 1B, 2B of the pistons 1, 2 are thus formed by one time of the operation of the movable punch 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a forging method, and particularly to a forging method that allows two products to be formed simultaneously with one stroke of a pressure ram.

[Conventional technology]

When forming a columnar product such as a piston for an internal combustion engine by forging, conventionally, as shown in FIG. a die 32 and a skirt portion 3 of the piston 31;
A stepped approximately cylindrical punch 33 whose unevenness is reversed to the shape of 1A.
A method of molding one molded product 31 from - pieces of rough material using Using a die 42 having a through hole 42A, and a pair of upper and lower punches 43 and 44 each having a stepped, approximately cylindrical shape, in which the unevenness is inverted to the shape of the skirt portion 41A of the molded product 41, - pieces of rough material are punched. A method is adopted in which a molded product 41 for two pistons is formed from the same.

[Problem that the invention seeks to solve]

However, among the conventional forging methods, the forging method shown in FIG. 3 can form only one molded product 31 with one stroke of the pressurizing ram of the press machine that supports the punch 33, resulting in low productivity. . In order to increase productivity with this additional forging method, the pinch of one stroke of the pressure ram should be shortened,
Although there are methods for shortening the time for removing and transporting the molded piston 31 from the press, both methods require modification of the press and the transfer device, which is a transport device, which is difficult.

Furthermore, among the conventional forging methods, the forging method shown in FIG. Because the two bones of
It is necessary to separate and cut into two pieces using a saw or milling machine in a separate process. Therefore, there is a problem in that productivity deteriorates and the yield of raw material decreases by the amount of cutting waste. Furthermore, since the cut surface of the molded product 41 is flat, in the case of a product that has a recess at the top that forms a combustion chamber, such as the piston of an internal combustion engine, this recess must be processed in a separate process. , productivity deteriorates further.

Therefore, an object of the present invention is to improve productivity in forging without major modification of press machines and other production equipment.

[Means for solving problems]

Therefore, in the present invention, a pair of punches are disposed opposite to each other on both sides of a hole formed through the die, an intermediate mold is placed in the middle of the hole of the die, and It is characterized in that a pair of rough materials are placed on both sides of the intermediate mold, and the molding is performed by pressing from both sides with the pair of punches.

Specifically, a hole having an inner surface shape that is the same as the outer shape of the cylindrical product after molding is formed through the die, and a hole having the shape of one end of the product is formed on both sides of the opening of the hole of the die. A pair of punches with tip shapes with reversed concave and convex shapes are installed,
An intermediate mold having an end surface shape on both sides of which the unevenness is reversed to the shape of the other end of the product is placed in the middle part of the die hole, and a set of rough materials is placed on both sides of the intermediate mold in the die hole. It is characterized in that the pair of punches is used to press-form the set of rough materials with an intermediate mold sandwiched therebetween.

[Effect]

According to the configuration of the present invention, a pair of punches is used to press-form a set of raw materials placed on both sides of the intermediate mold, so that the molding of both ends of the product of -m is performed. Machining can be done at once with one stroke of the punch.

〔Example〕

Next, a forging method according to an embodiment of the present invention will be explained based on the drawings.

FIG. 1 is a partial cross-sectional view of the main parts of a press machine that implements a forging method according to an embodiment of the present invention, showing the state after forming, and FIG. 2 is a partial cross-sectional view of the press machine shown in FIG. 1. shows the state before molding.

In FIG. 1, symbols l and 2 indicate a pair of engine pistons (hereinafter referred to as pistons) which are products after molding,
Reference numeral 3 indicates a die through which a hole 3A having an inner surface having the same outer shape as the outer shape of the piston 1.2 is formed, and reference numeral 4 indicates a die whose unevenness is reversed to the shape of the skirt portion IA of the one piston 1. The hole 3 of the die 3 has a tip shape and a hole 3 of the die 3.
One movable punch has the same outer shape as the inner surface of A, and reference numeral 5 denotes the skirt portion 2 of the other piston 2.
This is the other fixed punch having a tip shape with the convex and concave portions reversed to the shape of A, and an outer diameter smaller than the inner diameter of the hole 3A of the die 3. Among these, the movable punch 4 is attached to a pressurizing ram of a press machine (not shown) and slides in the vertical direction in the drawing.

The other fixed punch 5 is fixed to the press body together with the die 3. The pair of movable punch 4 and fixed punch 5 are disposed on both sides of the hole 3A of the die 3, facing each other. Reference numeral 6 denotes an intermediate type having on one side an end face shape in which the unevenness is inverted to the shape of the top part IB of the piston 1, and on the other side, an end face shape in which the unevenness is inverted to the shape of the top part 2B of the other piston 2. This intermediate die 6 is disposed in the middle of the hole 3A of the die 3. Symbol 7 is the piston after the molding -1
. It is slid through the gap with 3A by a knockout cylinder (not shown).

In FIG. 2, reference numeral 8 designates a blank material before being formed into the piston 1.2.

Next, the operation of this embodiment will be explained.

First, as shown in FIG. 2, a set of rough materials 8.8 is inserted into the hole 3A of the die 3 with the intermediate mold 6 sandwiched therebetween. Then, when the press machine is operated, the movable punch 4 moves to the second position.
As shown in the figure, the other fixed punch 5 descends downward.
and an intermediate mold 6 sandwiched between a set of blank materials 8, to form this set of blank materials 8 into a piston 1.2 having a predetermined shape as shown in FIG.

After molding, the movable punch 4 is raised upward as shown in FIG. 1, and the piston 1.2 remaining in the hole 3A of the die 3 is
Then, the sleeve knockout 7 is activated to push the intermediate mold 6 upward and discharge it.

After completion of ejection, one cycle of the forging process is completed with the sleeve knockout 7 being lowered and returned to its initial state.

In this way, with one operation of the movable punch 4, the two pistons 1 and 2 are simultaneously activated.
A depression corresponding to the combustion chamber can also be formed at the top parts IB and 2B of the combustion chamber. Note that the intermediate mold 6 can be used repeatedly.

In this embodiment, the two pistons l and 2 have the same shape, but the present invention is not limited to this, and as long as the balance between forward extrusion and backward extrusion is taken into consideration, two types of pistons with different shapes can be used. It is also possible to mold pistons.

The forging method according to the present invention includes cold forging, warm forging,
It can be applied to general forging processing such as hot forging, or molten metal forging.

〔Effect of the invention〕

As described above, according to the present invention, two products can be molded simultaneously with a single operation in one process with a very simple configuration, and the end of the product that is in contact with the punch can be molded at the same time. Since desired shaping can be performed also on the end portion on the opposite side, there is no need for major modification of existing equipment, and there is an excellent effect that productivity is greatly improved.

Furthermore, since the above-described forming can be performed only by forging, the yield of the material is greatly improved, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of the main parts of a press machine that implements a forging method according to an embodiment of the present invention, showing the state after forming, and FIG. 2 is a partial sectional view of the press machine of FIG. 1. The state before forming is shown, FIG. 3 is a cross-sectional view of the main parts of an example of a press machine that implements a conventional forging method, and FIG. 4 is a cross-sectional view of another example of a press machine that implements another conventional forging method. It is a sectional view of the main part. l, 2... Piston (product) IA, 2A... Skirt part (one end of the product) IB,
2B...Top (other end of the product) 3...Dice 3A...Hole 4...Movable punch (punch) 5...Fixed punch (punch) 6... Intermediate mold 8...Rough material

Claims (1)

[Claims] A hole having an inner surface having the same shape as the outer shape of the cylindrical product after molding is formed through the die, and on both sides of the opening of the hole of the die, a tip whose unevenness is reversed to the shape of one end of the product is formed. A pair of punches each having a shape are placed in the middle of the hole of the die, and an intermediate die having an end surface shape on both sides of which the unevenness is reversed to the shape of the other end of the product is placed in the middle of the hole of the die. A forging method characterized in that a set of rough materials is housed on both sides of an intermediate die, and the pair of punches press-forms the set of rough materials with the intermediate die sandwiched therebetween. .