JPS61165246A - Transfer warm closed forging method - Google Patents

Abstract

PURPOSE:To reduce the contact time between dies and heated stock and to improve the life of the dies in the titled forging method by supplying intermittently the stock to the dies and interposing a spacer which prohibits the contact of the upper and lower dies between the upper and lower dies while the stock is not supplied. CONSTITUTION:The heated annular stock 20 is inserted into the space between the lower die 8 and mandrel 10 of a transfer press machine and the upper die is lowered. The stock 20 is then closed and the upper die 14 pushes down the lower die 8 down to the bottom dead point of a press slide thereby, forming a gear. The die 14 is thereafter risen and the formed product A is ejected to behind the device, but the stock 20 is not supplied in succession thereto and in turn the space 34 delivered to be interposed between the upper and lower dies. Te die 14 is lowered in this state. The die 14 is then risen and the spacer 34 is retreated; at the same time, a parting material is supplied to the engraving part of the upper and lower dies. The stock 20 is then supplied and the next transfer warm closed forging is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses a transfer press machine to close a heated blank of steel or the like in a die-cutting space between an upper die and a lower die.
The present invention relates to a transfer warm closed forging method for die forging products into desired shapes.

Conventional technology For closed forging mold equipment, Japanese Patent Publication No. 54-33583
There are numbers, etc.

Problems to be Solved by the Invention When automatically and continuously producing products by transfer warm closed forging, the temperature of the mold rises significantly and the mold sag, so special mold cooling must be applied. There's a problem.

In contrast, by increasing the lifting cycle time of the upper mold and intermittently supplying material between the upper and lower molds, the contact time between the mold and the heated material can be shortened and the mold cooling effect can be improved. It was suggested that it be increased.

However, since this method involves closed forging, the upper and lower dies come into strong contact even during blank forging, which shortens the life of the dies.

That is, when blank punching is performed between the upper and lower molds, as in the case of a warm closed forging mold for a bevel gear shown in FIG. Therefore, there was a problem in that the main parts of the mold engraving, such as the tooth mold 14a, were easily damaged at an early stage, and the life of the mold was shortened.

Means for Solving the Problem Material is intermittently supplied to the mold, and a spacer piece is interposed between the upper and lower molds to prevent the upper and lower molds from coming into contact when the material is not supplied.

The contact time between the working mold and the heating material is shortened, and there is no need for contact between the upper and lower molds due to blank punching.

Example The present invention will be explained below based on examples.

FIGS. 1 and 2 are cross-sectional plan views of essential parts of a transfer warm closed forging process for a bevel gear in an embodiment of the present invention.

In the figure, 1 is a die set fixed on the bolster 2.
A cylindrical guide tube 3 is fixed to this guide set 1 with a ring 4. A ring cylinder 6 into which a ring piston 5 is vertically fitted is provided on the upper surface of the die set 1 in a portion surrounded by the guide cylinder 3. Reference numeral 6b denotes a plate whose lower surface is in contact with the guide tube 3 and fixed by the guide tube 3, and a plurality of pawls 7 pass through this plate 6b in the upward direction so that the lower end is in contact with the upper surface of the ring piston 5. It is provided so that it can slide freely. Reference numeral 8 denotes a lower mold which is slidably fitted into the guide cylinder 3, and its lower surface is supported by the upper end of the pole 7, and a ring 3a fixed to the upper part of the guide cylinder 8 prevents it from being pulled out. be. Lower mold 8
A die engraving 8a for shaping the lower surface of the molded product is formed at the axial center of the molded product.

Reference numeral 9 designates a knockout forming the bottom surface of the mold engraving 8a, and reference numeral 10 designates a mandrel for forming the inner diameter portion of the molded product A. The knockout 9 is elastically supported by a knockout pin 11 that is always urged upward.

Reference numeral 12 denotes a die set for an upper die fixed to the slide side, and an upper die 14 on which a tooth pattern 14a for forming the upper side of the molded product is formed is fixed to this die set.

The lower chamber 6a of the ring cylinder 6 of the Guiset 1 is
As shown in FIG. 3, a hydraulic cylinder 15k pressurized by air pressure is connected through a circuit 17 interposed with a check valve 16 that allows flow only in the direction of the ring cylinder 6. Further, a relief valve 18 is connected to the ring cylinder 6.

19 is a regulator interposed between the air chamber 15a of the hydraulic cylinder 15 and the compressor.

In the above configuration, the ring piston 5 is moved upward by a predetermined pushing force due to the hydraulic pressure acting on the ring cylinder 6, and therefore the lower die 8 is moved upward via the pawl 7 as shown in the left half of FIG. has been done.

Further, 30 is a bracket fixed to the outer periphery of the upper die set 12 and holds an air cylinder 31. A flexible rod 33 such as a tightly coiled coil spring or a plate spring is connected to the tip of the piston rod 32 of the air cylinder 31, and a spacing piece 34 made of a piece of steel or the like is connected to the other end of the flexible rod 33.
is installed.

The synchronization timing between the air cylinder 31 and the press machine is
For example, a necessary signal is extracted by a combination of a rotary cam of a press machine and a sensor output that detects material supply/non-supply.

Although not shown, a transfer device for conveying the material 20 and the molded product A is appropriately installed, and the transfer device is synchronously and interlocked with the press machine.

Next, a description will be given of transfer warm closed forging, which is performed by intermittently supplying a material to a die using the above-mentioned apparatus so that blank punching and forming are performed alternately.

First, a mold release agent is supplied to the mold engravings of the upper and lower molds, and then, as shown on the left side of FIG. 1, a ring-shaped heating material 20 is inserted into the space between the lower mold 8 and the mandrel 10. Move down.

As a result, the upper mold 14 comes into contact with the upper surface of the lower mold 8 to which a predetermined back pressure is applied, closing the material 20, and as shown on the right side of FIG. The lower mold 8 is pushed down to the point to complete the molding of the bevel gear.

Thereafter, the upper mold 14 is raised, and the molded product A is lifted by a knockout and transported by a transfer device (not shown).

Subsequently, as shown on the left side of FIG. 2, the material 20 is not supplied,
At the same time, the spacer piece 34 is sent out by the operation of the air cylinder 31 to be interposed between the upper and lower molds, and in this state, the upper mold 14 is moved down.

As a result, the upper die inserts the spacing piece 34 between it and the lower die 8 to which back pressure is applied, and as shown on the right side of FIG. 2, the upper die cannot come into direct contact with the lower die 8! Press down the lower die 8 to the bottom dead center of the press slide.

At this time, the lower mold 8 is lowered further below the lowered position when molding the material 20, and the spacer piece 34 is interposed between the upper and lower molds without being deformed.

Therefore, the tooth pattern 14a of the upper mold 14 and the die engraving 8a of the lower mold 8 are prevented from coming into contact with each other due to blank punching when the material is not supplied.

Thereafter, the upper mold 14 is raised, and the spacer piece 34 is also retracted by the operation of the air cylinder 31. At the same time, a mold release agent is supplied to the mold engravings of the upper and lower molds, and then the heated material 20 is supplied to the lower mold 8 to start the next molding.

The supply of mold release agent is also beneficial for mold cooling, but the lower mold 8
If it accumulates on the die engraving 8a or the upper end surface of the knockout, it will cause sinkage defects in the molded product, so it is best to use an intermittent feeding method that is carried out immediately before material feeding and is carried out only when material is not being fed.

In addition, as a method of making the upper and lower dies 14, 8 unable to contact when the material is not supplied, firstly, it is possible to utilize a mechanism that uses the brake and clutch of the press machine to stop the press slide for a limited time. , there is a durability problem as the brakes and clutches are overused, and secondly, the hydraulic circuit leading to the ring cylinder 6 is modified, and the upper mold 14 pushes the lower mold 8 down to the bottom dead center of the press slide to complete the molding. When this occurs, it is possible to stop the raising of the lower mold 8 in preparation for the next material supply failure, and if necessary, to lower the lower mold a little further from the lowered position of the lower mold 8, but it is possible to I have a sexual problem.

In this regard, according to the present invention, as in the above-mentioned embodiment, the upper and lower dies are caused to perform normal continuous lifting and lowering movements, and a spacer piece is simply interposed between the upper and lower dies, so that such a problem does not occur.

Effects As described above, according to the present invention, when products are automatically and continuously produced by transfer warm closed forging, the mold cooling effect can be enhanced without impairing the life of the mold.

[Brief explanation of drawings]

1 and 2 are cross-sectional plan views of essential parts of a bevel gear warm closed forging process in an embodiment of the present invention. Figure 3 is a back pressure adjustment circuit system diagram. FIG. 4 is an enlarged cross-sectional plan view of the main parts showing the blank firing state of the upper and lower dies. (Explanation of symbols) 8... Upper mold. １４・・・・・・Bottom
Type. 20...Material. A・・・・・・Number
Shape. 31...Air cylinder. 32...
piston rod. 38... Possible flexible rod. 34......interval piece.

Claims (1)

[Claims] When forging is performed by closing the heated material 20 between the upper and lower molds 14 and 8 using a transfer press machine, the material is intermittently supplied to the mold, and the upper and lower molds 14 and 8 are brought into contact when the material is not supplied. A transfer warm closed forging method characterized by interposing a disabling spacer piece 34 between the upper and lower dies.