JP3753220B2 - Forging apparatus and forging method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a forging device and a forging method. More specifically, the present invention compresses and forms a workpiece into a predetermined shape by abutting punches and dies that are opposed to each other and relatively close to and away from each other. The present invention relates to a forging device and a forging method including upsetting for the purpose.
[0002]
[Prior art]
In general, a forging device is provided such that a pair of dies and a punch are arranged to face each other and relatively close to and away from each other. When a workpiece is formed into a predetermined shape using such a forging device, the workpiece is disposed between a die and a punch, and the two are moved relatively close to each other and brought into contact with each other. Thus, the workpiece is compressed in a sealed or semi-sealed state between the die and the punch and plastically deformed so that the meat of the workpiece flows in the radial direction, and is formed into a predetermined shape corresponding to the die and the punch. The After the work is formed, the die and the punch are moved relatively apart from each other. At this time, so-called biting or sticking (collectively referred to as sticking) occurs in which the formed work (molded product) is in close contact with the punch. There is. In particular, the punch is often caused outs with tension when having a portion extending linearly (straight portion) in a direction substantially parallel to the moving direction. When continuous molding is performed with the molded product stuck to the punch in this way, the workpiece to be molded next and the molded product are pressed between the punch and the die, and both the workpiece and the die are damaged. Will be.
[0003]
As a conventional technique for preventing sticking of a molded product to a punch, as disclosed in Japanese Utility Model Laid-Open No. 61-27536, a die and a punch having a mandrel are used to form a cylindrical shape from a ring-shaped material. In the forging die for forming the molded product, a step portion for forming a surplus portion having a larger diameter than the outer shape of the molded product is formed at the opening end of the die, and above the die. A forging die is known in which a stripper is provided on which an upper end of a surplus portion of a molded product that bites into the punch comes into contact.
[0004]
As another conventional technique, as disclosed in Japanese Patent Laid-Open No. 8-243678, in a mold apparatus that performs forging with a pair of molds that can move relative to each other in a closing direction, at least one of them The mold is provided with a knockout ring having an extrusion surface continuous in the circumferential direction of the annular end surface of the forged product, and a knockout pin for driving the knockout ring in a direction protruding from the inner surface of the mold is provided behind the knockout ring, and 2. Description of the Related Art A forging die device is known which is provided with an urging means for returning the knockout ring to a predetermined position.
[0005]
[Problems to be solved by the invention]
However, among the conventional techniques described above, in the forging die disclosed in Japanese Utility Model Laid-Open No. 61-27536, it is necessary to form a surplus portion that contacts the stripper on the molded product. There was a problem that it had to be formed in a shape different from the originally desired shape. If there is a problem if there is a surplus part, it must be removed by subsequent machining or the like (specification, page 8, line 10 to line 14), which increases the number of processes and reduces costs. There was a problem that it took.
Further, in this case, it is necessary to provide the stripper separately from the die so as to protrude upward from the die, that is, the structure is complicated.
[0006]
Of the conventional techniques described above, in the forging die device disclosed in Japanese Patent Laid-Open No. 8-243678, a knockout ring, a knockout pin, and an urging means are provided in at least one die (implementation). In the example, the other type is also provided with a knockout pin).
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a forging device and a forging method capable of reliably releasing sticking of a forged workpiece to a die with a simple configuration.
[0008]
In order to achieve the above object, the forging apparatus according to claim 1 is disposed so as to be opposed to each other and relatively close to and away from each other, and by being abutted, the workpiece is compressed and formed into a predetermined shape. A forging device equipped with a punch and a die, which is formed on the inner peripheral surface of the die and has a diameter due to compression of the workpiece stuck to the punch when the workpiece moves with the relative separation between the punch and the die. the radial stress releasing means for releasing the direction stress, is formed so as to protrude into the die adjacent to the該径direction stress releasing means, radially by compression I accompanied a relative further separation of the punch and die And a movement preventing means for releasing the sticking of the work to the punch by engaging with the work whose stress has been released and preventing the movement of the work .
[0009]
Further, in order to achieve the above object, the forging method according to claim 2 compresses the workpiece by abutting a punch and a die that are arranged to face each other and relatively close to each other. When the workpiece moves with the relative separation between the punch and the die after forming into a predetermined shape, the diameter of the workpiece stuck to the punch is compressed by the radial stress release means formed on the inner peripheral surface of the die. The radial stress due to the compression is applied to the movement preventing means formed to release the directional stress and then project into the die adjacent to the radial stress releasing means due to the relative separation between the punch and the die. The released work is engaged to prevent the movement thereof, and the sticking of the work to the punch is released .
[0010]
In the invention of claim 1, the workpiece placed between the punch and the die, and a punch and a die are relatively close abutment molded by compressing the workpiece into a predetermined shape. At this time, the workpiece is plastically deformed so as to expand in the radial direction by being compressed in the axial direction to generate a radial stress, and in addition to this radial stress and oil attached to the surface of the workpiece, etc. It will stick to or bite into the mold. Then, when the forming is completed and the punch and the die are relatively separated from each other , the workpiece sticks to the punch and moves as the punch moves relative to the die . However, freed radial stress generated in the work by the radial stress releasing means formed on the inner peripheral surface of the die, then the movement of the workpiece with sticking or biting the punch is prevented by movement hampering means, sticking release the. By releasing the radial stress, the workpiece can be securely released from the punch by the movement preventing means.
[0011]
In the invention of claim 2, the workpiece placed between the punch and the die, and a punch and a die are relatively close abutment molded by compressing the workpiece into a predetermined shape. At this time, the workpiece is plastically deformed so as to expand in the radial direction by being compressed in the axial direction to generate a radial stress, and in addition to this radial stress and oil attached to the surface of the workpiece, etc. When the molding is completed and the punch and the die are moved relatively apart from each other, the workpiece is stuck to the punch and moved. At this time, the radial stress releasing means formed on the inner peripheral surface of the die is used to release the radial stress generated in the workpiece, and then, the radial stress releasing means is provided adjacent to the radial stress releasing means so as to protrude into the die. the formed movement preventing means engaging the workpiece to prevent movement of that canceling the sticking of the workpiece relative to the punch. Since the movement of the workpiece stuck or punched on the punch is prevented from moving in a state in which the radial stress is released, the workpiece can be easily and reliably released from sticking .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, an embodiment of the forging device of the present invention will be described in detail mainly based on FIG. The forging device of the present invention is generally arranged so as to be opposed to each other and relatively close to and away from each other, and by being abutted against each other, a punch 1 and a die 2 that compress a workpiece W in an axial direction to form a predetermined shape. The axial direction of the workpiece (molded product) W ′ formed on the inner peripheral surface of the die 2 and attached to the punch when the workpiece moves with the relative separation between the punch 1 and the die 2 The radial stress releasing means 21 for releasing the radial stress P due to the compression of the material and the radial stress releasing means 21 are formed adjacent to the radial stress releasing means 21 so as to protrude into the die 2 so that the punch and the die are relative to each other. 'and prevents movement thereof engages the workpiece W with respect to the punch 1' work W along with the spaced having a movement preventing means 22 for releasing the sticking of the.
[0013]
As shown in FIG. 1, the workpiece W in this embodiment is preformed from a blank (not shown) formed in a substantially disc shape, so that the flange portion WF, the leg portion WL, and the axial direction are formed. A through hole WH is formed. In addition, as shown in FIG. 2, the molded product W ′ molded by the forging device in this embodiment has a flange portion WF ′ that is thinner in the axial direction than the flange portion WF of the workpiece W before being molded, and It is formed so as to increase in the radial direction. Further, the leg portion WL ′ of the molded product W ′ is formed so as to be longer in the axial direction than the leg portion WL of the workpiece W before molding and to have a stepped portion on the outer periphery.
[0014]
Oite to this embodiment, the die 2 disposed below, consists of a die 2 phases oppositely disposed punch 1 Tokyo, punch 1 descends, provided to rise against the die 2 ing. The punch 1 includes an inner mold 10 that forms a hole WH formed in the workpiece W into a tapered hole WH ′ as shown in FIG. 2, and an outer mold 11 that is disposed concentrically around the inner mold 10. It consists of. The inner mold 10 is formed in a substantially cylindrical shape and has a straight portion 10a whose outer peripheral surface extends linearly in a direction substantially parallel to the moving direction of the punch, and is provided at the tip of the straight portion 10a via a stepped portion. And a tapered portion 10b. Further, the outer mold 11 has a tip that can be compressed in the axial direction in a state of being sealed (closed) so that the flesh of the flange portion WF of the workpiece W does not escape between the outer flange 11 and the flange forming portion 2a of the die 2 described later. A surface 11a is provided. The punch 1 can have an integral configuration in which the inner mold 10 and the outer mold 11 are not relatively movable in the axial direction, or can be configured to be relatively movable in the axial direction, as necessary.
[0015]
Since the molded product W ′ is formed into a predetermined shape from the workpiece W as described above, the die 2 is inserted without interference between the flange formation 2a, the stepped leg formation portion 2b, and the taper portion 10b of the inner mold 10. And a knockout pin (not shown) for taking out the molded product W ′ from the die 2 is disposed below the hole 2c.
[0016]
Further, a groove 21 is integrally formed above the flange forming portion 2a of the die 2 as a radial stress releasing means for releasing the radial stress P due to compression of the molded workpiece (molded product) W ′. In addition, a protrusion 22 is integrally formed above the groove 21 as a movement blocking means for blocking the movement of the molded product W ′ accompanying the relative separation between the molds 1 and 2.
[0017]
The groove 21 raises the punch 1 after completion of molding, and the molded product W ′ stuck to the punch 1 is moved up and moved along with the upward movement, and the flange portion WF ′ of the molded product W ′ is positioned in the groove 21. In this case, the radial stress generated between the outer peripheral surface of the straight portion 10a of the inner mold 10 and the inner peripheral surface of the flange forming portion 2a of the die 2 by compressing the flange portion WF of the workpiece W in the axial direction ( (See the arrow P in FIG. 3) that can be released in the radial direction, that is, with a diameter that makes a large diameter having a predetermined difference radially outward from the inner peripheral surface of the flange forming portion 2a, Is formed over. The depth in the radial direction of the groove 21 varies depending on the size of the flange portion WF ′ itself of the molded product W ′, the size of the radial stress P received by the flange portion WF ′, and the like. It can be set to about 0.10 mm.
[0018]
On the other hand, as described above, the protrusion 22 can hook the flange portion WF ′ of the molded product W ′ from which the radial stress P has been released when passing through the groove 21 and can take out the molded product W ′. That is, when a knockout pin (not shown) disposed in the hole 2c of the die 2 is driven with a diameter slightly smaller than the diameter of the outer peripheral edge of the flange portion WF ′ from which the radial stress P has been released. The diameter is such that the outer peripheral edge of the flange portion WF ′ from which the radial stress P has been released passes, and is formed so as to protrude inward at a position adjacent to the direction in which the punch 1 of the groove 21 moves away. In this embodiment, the case where the protrusion 22 is formed over the entire circumference is shown in the figure, but it may be partially formed so as to be intermittent in the circumferential direction.
[0019]
The grooves 21 and protrusions 22 integrated with the die 2 configured as described above are formed at the same time when the flange forming portion 2a, the stepped leg forming portion 2b, and the hole 2c are formed in the die 2 by cutting or the like. can do.
[0020]
Next, one embodiment of the forging method of the present invention will be described based on FIGS. 1 to 5 by using a forging device configured as described above. The forging method of the present invention is generally performed by compressing a workpiece W in the axial direction by abutting a punch 1 and a die 2 which are opposed to each other so as to be relatively close to each other and can be separated from each other. When the workpiece (molded product) W ′ formed along with the relative separation between the punch 1 and the die 2 moves, the radial stress releasing means 21 formed on the inner peripheral surface of the die 2 causes the punch 1 to The radial stress P due to the compression of the workpiece W ′ stuck to the die is released, and then the punch 1 and the die 2 are further separated from each other, so that the radial stress releasing means 21 is provided next to the die 2 in the die 2. The movement preventing means 22 formed so as to protrude is engaged with the workpiece W ′ released from the radial stress due to the compression, the movement is prevented, and the sticking of the workpiece W ′ to the punch 1 is released. .
[0021]
When starting forging forming of the workpiece W, as shown in FIG. 1, the punch 1 is raised and separated from the die 2, and the flange portion WF, the leg portion WL, and the axial direction are preliminarily formed. A workpiece W in which a hole WH penetrating through is formed on the die 2. From this state, when the punch 1 is lowered and brought into contact with the die 2, the workpiece W has a flange portion WF having a front end surface 11 a of the outer mold 10 of the punch 1 and a flange forming portion 2 a of the die 2 as shown in FIG. Are rolled by being plastically processed so as to be compressed in the axial direction, and the leg portion WL is expanded in the radial direction, and the leg portion WL is formed with the stepped leg portion 2b of the inner die 10 of the punch 1 and the die 2. 2, a step portion is formed on the outer periphery and is extended in the axial direction, and the center portion is tapered by the inner die 10 of the punch 1 as shown in FIG. 2. A molded product W ′ in which a hole WH ′ having a shape is formed is molded.
[0022]
As the flange portion WF of the workpiece W is compressed in the axial direction and expanded in the radial direction, the flange portion WF ′ of the molded product W ′ has the flange forming portion 2a of the die 2 as shown by an arrow P in FIG. A compressive stress P is generated in the radial direction between the inner periphery and the outer peripheral surface of the straight portion 10 a of the inner mold 10 of the punch 1. When the molded product W ′ is taken out and the punch 1 is raised so as to carry in the workpiece W of the next molding cycle, the radial compression stress P generated in the flange portion WF ′ of the molded product W ′ causes the punch 1 to move. The molded product W ′ bites into the straight portion 10a, and the molded product W ′ sticks to the punch 1 by oil (not shown) attached between the molded product W ′ (work W) and the punch 1 or the like. The molded product W ′ moves up and moves together with the punch 1 without being prevented from moving up due to the rise of the punch 1.
[0023]
However, in the forging device configured as described above, the radial compressive stress P generated in the flange portion WF ′ of the molded product W ′ is flanged in the groove 21 formed above the flange forming portion 2 a of the die 2. When the part WF ′ is located, it is released as indicated by an arrow R in FIG. Further, when the punch 1 is further raised, the molded product W ′ from which the radial compressive stress P of the flange portion WF ′ is released is a protrusion 22 formed above the groove 21 as shown in FIG. By engaging the outer peripheral edge of the flange portion WF ′, the movement associated with the rise of the punch 1 is prevented and the die 2 remains reliably. Next, the punch 1 is further raised and separated from the die 2 until the molded product W ′ can be taken out, and then a knockout pin (not shown) disposed in the hole 2c of the die 2 is driven so that the flange portion WF ′ with respect to the protrusion 22 is driven. The molded product W ′ is taken out from the die 2 against the engagement of the outer periphery of the die 2.
[0024]
Here, without providing the groove 21 as a means for releasing the radial stress P of the molded product W ′, the protrusion 22 as a movement preventing means for preventing the movement of the molded product W ′ accompanying the rise of the punch 1. In the case where only the punching 1 is provided, in addition to the radial stress P occurring in the molded product W ′, the molded product W ′ is further compressed in the radial direction by the protrusions 22, and the biting or sticking of the molded product W ′ to the punch 1 is further strengthened. Sometimes it is done. Therefore, in the present invention, the groove 21 as a means for releasing the radial stress P of the molded product W ′ and the protrusion 22 as a means for preventing the movement of the molded product W ′ accompanying the rise of the punch 1. Is an essential combination.
[0025]
The present invention is not limited to the above-described embodiment, and can be applied to other forges as long as radial stress P is generated in the molded product W ′ by forging. The term “forging” here includes “upsetting”.
[0026]
【The invention's effect】
According to the first aspect of the present invention, when the workpiece is moved along with the relative separation between the punch and the die, the radial stress due to the compression of the workpiece stuck to the punch is formed on the inner peripheral surface of the die. the radial stress releasing means for releasing, is formed so as to protrude into the die adjacent to the該径direction stress releasing means, punch and relative radial stresses due to compression What accompanied to a further separation of the die release And a movement preventing means for releasing the sticking of the work against the punch by engaging with the formed work and preventing the movement of the work, and securely releasing the sticking of the forged work to the mold. It is possible to provide a forging device that can
[0027]
According to the invention of claim 2, the radial direction formed on the inner peripheral surface of the die when the workpiece moves with the relative separation between the punch and the die after the workpiece is compressed into a predetermined shape. The stress relief means releases the radial stress due to the compression of the workpiece stuck to the punch, and then projects into the die adjacent to the radial stress relief means by the relative separation between the punch and the die. to the formed movement hampering means, the radial stress due to compression is released the workpiece is engaged to prevent movement thereof in a simple structure that releases the sticking of the workpiece with respect to the punch, and forging the workpiece It is possible to provide a forging device that can reliably release the sticking to the mold.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of a forging device according to the present invention in a state before forming a workpiece.
FIG. 2 is a cross-sectional view when the punch is brought into contact with a die from the state of FIG.
FIG. 3 is a partially enlarged cross-sectional view of FIG. 2 for explaining a state in which a radial compressive stress is generated in a flange portion of a molded product.
4 is a partially enlarged cross-sectional view for explaining a state in which the punch is moved upward from the state of FIG. 3 and the radial compressive stress of the molded product attached to the punch is released by the groove. FIG.
5 further raises the punch from the state of FIG. 4, the outer peripheral edge of the flange portion released from the radial compressive stress is engaged with the protrusion, and the movement of the molded product accompanying the upward movement of the punch is prevented. It is a partial expanded sectional view for demonstrating the state which met.
[Explanation of symbols]
W Work W 'Molded product P Radial stress 1 Punch (one mold)
2 Dice (the other type)
21 groove (radial stress relief means)
22 Protrusion (Movement prevention means)

Claims (2)

It is a forging device provided with a punch and a die that are arranged so as to be relatively close to each other and can be separated from each other and pressed to form a predetermined shape by compressing the workpiece,
A radial stress releasing means that is formed on the inner peripheral surface of the die and releases the radial stress due to compression of the workpiece stuck to the punch when the workpiece moves with relative separation of the punch and the die ;
Is formed so as to protrude into the die adjacent to the該径direction stress releasing means, the radial stress due to compression What accompanied the relative further separation of the punch and die engage the freed workpiece a movement preventing means for canceling the sticking of the workpiece with respect to the punch and prevent movement,
A forging device comprising: After the workpiece is compressed and molded into a predetermined shape by abutting punches and dies arranged so as to face each other and relatively close to and away from each other,
When the workpiece moves with the relative separation between the punch and the die , the radial stress releasing means formed on the inner peripheral surface of the die releases the radial stress due to the compression of the workpiece stuck to the punch ,
Then, by the relative further separation between the punch and the die, the workpiece in which the radial stress due to the compression is released is engaged with the movement preventing means which is formed adjacent to the radial stress releasing means and protrudes into the die. The forging method is characterized in that the movement is prevented and the sticking of the workpiece to the punch is released .

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