JPH02220727A - Die forging method, die forging equipment and die - Google Patents

Abstract

PURPOSE:To efficiently execute die forging at a high temperature and at a high speed by blowing high temperature gas from the outside into a gas passage of the inside of the die in the top or the bottom dead center, and bringing a material to be forged to pressure forming, while heating intermittently the die. CONSTITUTION:The upper and the lower dies 3, 3' installed in the upper and the lower anvils 2, 2' are used, and hot die forging is executed with a hammer 1. In the method, it is detected by a position sensor S that the upper and the lower dies 3, 3' are positioned in the top and the bottom dead centers, a solenoid opening/closing valve V provided on a combustion gas supply duct line F through a controller C is operated, and burners 4, 5 are ignited. High temperature gas generated thereby is blown from an inlet gas hole 16 into a gas passage provided in advance on the inside of the dies 3, 3'. In such a way, while heating intermittently the dies 3, 3' and holding them at a prescribed high temperature, forging can be executed.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a die forging method, a die forging device, and a die, and is particularly applicable to high-temperature and high-speed forging such as hot die forging using high-speed forging equipment such as a hammer. The present invention relates to a suitable die forging method, die forging apparatus, and die.

[Conventional technology]

As is well known, in hot die forging, the die used is preheated before the start of forging, and the die is preheated during forging in order to prevent the temperature of the forged material from decreasing and the die from thermal response cracking. G Appropriate heat is applied to keep it warm.

In normal hot die forging, a method is generally adopted in which appropriate heat is applied externally using a gas burner or the like to maintain the temperature. In forging and isothermal die forging, in which the material is heated to the same temperature range as the material to be forged, heating means such as electric resistance heating or electromagnetic induction heating equipment are attached to the die.
These heating means maintain a high temperature within a predetermined range.

In addition, high-speed forging equipment such as hammers is often used for normal hot die forging, while equipment capable of low-speed pressurization such as hydraulic presses is used for real die forging and constant temperature die forging. .

[Problems to be Solved by the Invention] Recently, with the progress of industrial technology, products made of difficult-to-forge high alloys and special metal materials are increasing.

In order to forge these difficult-to-forge metal materials with a die,
In terms of internal quality, dimensional accuracy, and efficiency, it is desirable to apply real die forging or constant temperature die forging. It has only been put into practical use in
Currently, high-speed forging equipment such as hammers that can be expected to perform high-speed and highly efficient die forging cannot be used.

This is because when making 12 molds using high-speed forging equipment such as a hammer, the mold moves at high speed and is subjected to a large impact force, so a heating means is attached to this mold. This is because it would be difficult or practically impossible to do so.

Therefore, in order to efficiently form difficult-to-forge metal materials by taking advantage of high-speed forging equipment that is capable of high-speed and highly efficient die forging, the present inventors conducted die forging while maintaining the die at a high temperature. As a result of careful consideration of possible methods and configurations,
Focusing on the point where these molds move on to the next stroke after they temporarily stop at the top or bottom dead center, they believe that if they add a device to effectively heat the molds from the outside when they stop, the desired purpose can be achieved. This conclusion has been reached and the present invention has been completed.

That is, the present invention enables forging to be performed while maintaining the mold at a desired high temperature by applying intermittent heating to the mold from the outside during forging without directly attaching a heating means to the mold. The object of the present invention is to provide a die forging method, a die forging device, and a die.

[! ! Means for Solving the Problem] In order to achieve the above object, the present invention has the following configuration. That is, in the die forging method according to the present invention, when the die is located at the top or bottom dead center, high-temperature gas is introduced from the outside into the gas passage provided in advance inside the die. The material to be forged is press-formed while blowing into the mold and heating the mold intermittently.

Further, the die forging device according to the present invention includes upper and lower anvils, one or both of which are included in the pressurizing means, a pair of upper and lower dies attached to these anvils, and upper and lower dies for heating these dies. and a lower burner, wherein the pair of dies has a gas passage whose entrance side is open on the burner side side, and the upper and lower burners are provided with a pair of dies, These are located to the sides of the top and bottom dead centers of each mold.

Further, the mold according to the present invention includes a main mold having a recess on the kissing surface side, and a nesting mold fitted into the recess of the main mold and having an impression on the kissing surface side. The mold includes a gas passage groove provided around the inner peripheral surface of the recess of the main mold and/or an outer peripheral surface of the nested mold, and an inlet that communicates the gas passage groove with the outer surface of the main mold. It is equipped with side and outlet gas holes.

[Effect]

In the die forging method according to the present invention, high-temperature gas is blown from the outside into the gas passage provided in advance inside the die, so that the die can be heated from the inside by this high-temperature gas. The high temperature gas is blown in when the mold is at the top or bottom dead center, that is, when the mold is once stopped at a certain position 1, so the blowing can be easily done from the outside. In addition, since this can be carried out each time a pressurizing stroke is performed, the material to be forged can be press-formed while the die is intermittently heated during forging and maintained at a high temperature.

Further, in the die forging apparatus according to the present invention, the upper and lower pairs of dies attached to the upper and lower anvils are located to the side of the top and bottom dead center positions of the pairs of dies. Upper and lower heating burners are provided, and these pairs of molds are
The burner side has a gas passage that opens on the inlet side, so when the upper mold is at the top dead center and the lower mold is at the bottom dead center, the high temperature combustion gas of the upper and lower burners is released. , can be blown into the internal gas passages from the respective openings of these molds.

Furthermore, in the mold according to the present invention, there is provided a gas passage groove provided inside the inner peripheral surface of the recess of the main mold and/or an outer peripheral surface of the lower mold, and a gas passage groove that is connected to the main mold. A gas flow path consisting of an inlet and an outlet gas hole is formed in communication with the outer surface of the mold, so high temperature gas can be blown from the outside through the inlet gas hole on the outer surface. A high-temperature gas flow is formed that flows along the outer peripheral surface of the lower mold and reaches the outside through the outlet gas hole, and the heat of this high-temperature gas can heat the mold from the inside. Furthermore, the gas passage groove of the mold is integrated by inserting the lower mold into the recess of the main mold.
Since it is located on the inner and outer surfaces of each before
Can be easily processed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a partially cutaway front view showing the main parts of the die forging device of this embodiment, and Fig. 2a is a front sectional view showing the die attached to the forging device of Fig. 1. , FIG. 2 is a sectional view taken along line AA in FIG. 2a.

In FIG. 1, (1) is a hammer, and this hammer (1) is a counter blow type hammer.

(2) (2") are upper and lower anvils, and these upper and lower anvils
The lower anvils (2)'(2') are interlocked with each other by drive means, not shown here.

(3) and (3") are upper and lower molds, and these upper and lower molds (3) (3') are the upper and lower anvils (21 (2')
They are removably attached in pairs.

In addition, these upper and lower molds (3) (3'') are composed of a main mold (11) having a recess rm on the kissing surface side, and a main mold (11) having a recess rm on the kissing surface side, as shown in FIG. 2a and FIG. It is a nested mold with a lower mold 0 which is fitted into the recess Ob of the mold 00 and has an impression 0 bleed on the kissing surface side.
Inside thereof, a gas passage groove 09 provided around the inner peripheral surface of the main mold (recess 02 of 10) and an inlet gas which communicates this gas passage groove θω with one side of the main mold 01) are provided. A gas flow path consisting of the hole 0ω and the outlet side gas hole θ which communicates with the other side surface is provided.

Further, the main mold (11) and the lower mold 02 are firmly connected by a fixing pin 08).

In this example, the main mold 01) is a hot mold steel (J
IS; 5KT4), and the lower mold 03) was made of a heat-resistant alloy (AST old^-286).

On the other hand, in Fig. 1, (4) and (5) are upper and lower burners, and these upper and lower burners (4 and 5) are mounted on independent support columns ( 6), and these upper and lower burners (4)
(5) is the upper and lower mold (3) at the top and bottom dead center positions (
3'), and is fixed at a position corresponding to the inlet gas hole 00 with its tip facing the inlet gas hole 00.

The combustion gas supply pipes F for the upper and lower burners (4) and (5) are equipped with electromagnetic on-off valves. On-off control is performed by opening and closing valve (2).

In addition, a height position sensor S for the upper anvil (+) is provided at the top of the support column (6) and is connected to the control unit Hc of the electromagnetic on-off valve (■). When the lower die (3') is at the top dead center (at this time, the lower die (3') is at the bottom dead center), the electromagnetic on-off valve ■ is operated to open via the control device C, while the upper die (2) is opened. It is supposed to close immediately when it is scraped from top dead center.

1. The opening degree of electric I & n l'j71 closing valve ■ is limited.
The upper and lower burners (
4) The combustion output in (5) is controlled by this control device C.

With the die forging apparatus of this embodiment having the above configuration,
A titanium alloy (6Al-4V) material having an optimum forging temperature range of 900 to 950'C was forged with a die to produce a titanium alloy disk.

First, the upper and lower molds (31 (3°)) are preheated to 500°C and attached to the upper and lower anvils (2) (2'), then these are positioned at the top and bottom dead centers, Upper and lower burners (4
) (The temperature was raised to within the range of 600 to 700°C at step 51.

Then, the titanium alloy material heated to 950°C was set between upper and lower molds (3H3°), and was repeatedly blown to perform mold forging.

The number of blows per workpiece in this die forging is around 10, and the upper and lower dies (31 (3') are intermittently heated at the top, bottom, and dead center each time this blow is made, and During workpiece replacement, the workpieces were placed at top and bottom dead centers and heated.

The surface temperature of the forged material immediately after the completion of this die forging is 870.
°C, and the product after cooling had the expected good dimensional accuracy with no missing parts.

On the other hand, the upper and lower molds (3) (3') immediately after the completion of mold forging
The surface temperature of the impression part was 610°C, which was approximately the same temperature as the surface temperature of the rolling part at the start of forging, 650°C, and the effectiveness of the present invention was confirmed.

As described above, according to the die forging apparatus and forging method of this embodiment, in the die forging process in which the material to be forged is formed by repeatedly applying impact loads, the inside of the die is・It can be heated intermittently by blowing high-temperature combustion gas from the lower burner, and the heating means can be installed outside the mold, which moves at high speed and is subjected to impact loads. Therefore, even in a high-speed forging device, it is possible to easily carry out hot die forging, etc., which requires raising and maintaining the temperature of the die during forging close to the heating temperature of the material to be forged.

Furthermore, since the IT forgeable metal material can be forged with a die at high temperature and high speed, the scope of application of these high speed forging equipment can be expanded. In addition, the mold used in this experiment can heat the inside not only during forging and workpiece replacement, but also during preheating before forging, so the preheating can be done evenly inside and outside and in a short time. It can also be achieved by

Note that although the upper and lower molds used in this implementation had one gas hole each on the inlet and outlet sides, it is also possible to provide more than one gas hole each depending on the scale of the mold and the application target. . Further, in this embodiment, a counter-blow hammer is used as the forging machine, but a single-stroke drop hammer, a high-speed forging machine such as a crank press or a screw press may also be used.

〔Effect of the invention〕

As described above, according to the die forging method, die forging apparatus, and die according to the present invention, there is no need to directly attach a heating means to the die, and the die is intermittently heated from the outside during forging. It is possible to perform forging while maintaining the mold at the desired high temperature by applying high-speed heating, making it possible to carry out high-temperature and high-speed mold forging using high-speed forging equipment, and efficiently processing difficult-to-forge metal materials. This will help expand the means for forming and expand the range of applications for high-speed forging equipment.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing the main parts of a die forging device according to an embodiment of the present invention, and Fig. 2a shows a die attached to a die forging device according to an embodiment of the present invention. FIG. 2A is a sectional view taken along the line A-A in FIG. 2a. (]) - hammer (2) - upper anvil, (
2'L-lower anvil, (3)-upper mold, (3')
~Lower mold, (4)-upper burner, (4'L-lower burner, (ll)-main mold, 021-recess,
θ■ - lower mold, θ two impressions, 0ω - inlet gas hole, F - combustion gas supply pipe, C - control device, gas passage groove, outlet gas hole, electromagnetic shut-off valve, position sensor patent Applicant Kobe Steel Co., Ltd. Representative Patent Attorney Akira Kanemaru - Figure 1 Figure 2 a

Claims (3)

[Claims] (1) During die forging, when the die is at the top or bottom dead center, high-temperature gas is blown from the outside into the gas passage pre-installed inside the die to intermittently heat the die. A die forging method characterized by press forming the material to be forged. (2) Mold forging comprising upper and lower anvils, one or both of which have pressure means, a pair of upper and lower dies attached to these anvils, and upper and lower burners for heating these dies. The device, wherein the pair of molds has a gas passage inside which is opened on the inlet side on the burner side, and the upper and lower burners are arranged at top and bottom dead center positions of the pair of molds, respectively. A die forging device characterized in that it is located on the side of the die forging device. (3) A mold comprising a main mold having a recess on the kissing surface side, and a nesting mold fitted into the recess of the main mold and having an impression on the kissing surface side, the mold comprising: A gas passage groove is provided around the inner peripheral surface of the recess of the mold and/or the outer peripheral surface of the nested mold, and inlet and outlet gas holes are provided to communicate the gas passage groove with the outer surface of the main mold. A mold that is characterized by: