JP4585724B2 - Forging equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a forging apparatus, and more particularly to a forging apparatus that can significantly extend the life of punches and dies.
[0002]
[Prior art]
Forging is widely used as a means for plastically deforming a workpiece into a desired shape.
[0003]
The principal part longitudinal cross-section block diagram of the general forge molding apparatus for performing such a forge process is shown in FIG. The forging apparatus 1 is for obtaining a molded product 10 whose cross section is shown in FIG. 5, a die 3 provided with a cavity 2 having a shape corresponding to the external shape of the molded product 10, and the molded product 10. And a punch 4 having a shape corresponding to the internal shape.
[0004]
Among these, the die 3 is supported by a support plate 5 disposed below the die 3. The die 3 and the support plate 5 are attached to the forging apparatus 1 by a holder 6 fitted on the die 3 and the support plate 5.
[0005]
Here, a through hole 7 is formed in the die 3 and the support plate 5, and a knockout pin 8 for taking out a molded product 10 that has been forged from the forging apparatus 1 is inserted into the through hole 7. Has been. That is, the knockout pin 8 is connected to a first drive mechanism (not shown), and is displaced in the vertical direction in FIG. 4 as the first drive mechanism is biased.
[0006]
On the other hand, the punch 4 is also connected to a second drive mechanism (not shown), and approaches or separates toward the die 3 as the second drive mechanism is biased.
[0007]
The forging process using this forging apparatus 1 is performed as follows.
[0008]
First, a workpiece (not shown) is placed in the cavity 2 with the punch 4 being separated from the die 3. Next, the second drive mechanism is energized to lower the punch 4 and insert it into the cavity 2. Accordingly, the workpiece is supported by the die 3 while being pressed by the punch 4, and as a result, the workpiece undergoes plastic deformation. That is, the outer shape corresponds to the shape of the cavity 2 and the inner shape corresponds to the shape of the punch 4.
[0009]
The obtained molded product 10 is pushed out of the cavity 2 by the knockout pin 8 displaced upward in FIG. 4 as the first drive mechanism is energized, and is thereby removed from the forging apparatus 1. It reaches.
[0010]
[Problems to be solved by the invention]
The die and punch are required to have excellent wear resistance and high strength. From such a viewpoint, it is becoming mainstream to employ sintered high-speed tool steel (hereinafter referred to as powder high-speed steel) as a constituent material of the die and punch. However, for example, when it is attempted to increase the molding speed in order to improve the production efficiency of the molded product, it is difficult to say that the wear resistance of the powdered high-speed steel is necessarily sufficient.
[0011]
Thus, it is recalled that the die or punch is made of a hard material that is superior in wear resistance compared to powdered high-speed steel. Examples of such a hard material include a cemented carbide obtained by sintering WC powder and Co powder, and a cermet obtained by sintering TiC powder and Mo powder. A die and punch made of a gradient composite material proposed by the present applicants in Japanese Patent Application Laid-Open No. 2000-301279, in which the ceramic composition ratio decreases from the surface to the inside and the metal composition ratio increases, is also disclosed. Excellent wear resistance compared to powder high-speed steel.
[0012]
However, if a forging process is actually performed using a die made of such a hard material and a punch made of powdered high-speed steel, the life of the punch will be significantly shortened. That is, a die and a punch made of a hard material and a powdered high-speed steel, while a die and punch have a life of about 100,000 shots in a forging apparatus (hereinafter referred to as Conventional Technology 1) having a die and a punch made of powdered high-speed steel. In the forging apparatus (hereinafter referred to as “prior art 2”) having a punch made of the above, the life of the die is doubled to about 200,000 shots, but the life of the punch is about 30,000 shots to 1/3 or less. On the contrary, if forging is performed using a die made of powdered high-speed steel and a punch made of a hard material, the die will have a short life.
[0013]
When such a situation occurs, the operation of the forging apparatus must be stopped and the punch or die that can no longer be used must be replaced. Therefore, the production efficiency of the molded product is lowered, and the purchase cost of punches and dies is increased. That is, the malfunction that processing cost rises is caused. The above situation is that the support plate 5 is made of a relatively soft material such as SKD61 material or SKH57 material in order to relieve the stress acting on the die or punch during forging, and this support plate 5 is forged. Sometimes it is difficult to avoid even elastic deformation.
[0014]
In addition, there are some errors in the dimensions of the die and punch. For this reason, there is a difference between the molded product by the forging device before replacing the die or punch and the molded product by the forging device after replacement. Dimensions may vary. That is, when the die or punch is frequently replaced, there is a problem that the dimensions of the molded product may vary.
[0015]
The present invention has been made in order to solve the above-described problems. Even when a die or punch made of a hard material such as cemented carbide, cermet, or graded composite material is provided, the life of the die or the punch is extended. Therefore, it is an object of the present invention to provide a forging apparatus that can reduce processing costs and avoid variations in dimensions of a molded product.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a die provided with a cavity, a holder externally fitted to the die, a support plate disposed below the die, and a punch inserted into the cavity. Forging molding device comprising
An insert member having a Young's modulus of 70 to 200 GPa is interposed between the die and the support plate in a state of being separated from the inner wall of the insertion portion of the holder.
[0017]
In the forging device thus configured, when forging is performed on a workpiece, the stress generated from the workpiece is consumed to elastically deform the insert member. Furthermore, in such an insert member, when the stress is transmitted, the impedance difference between the longitudinal wave component and the transverse wave component of the stress wave becomes remarkably large. That is, while the impedance of the longitudinal wave component is about 50 to 100, the impedance of the transverse wave component is about 8 to 46. Under such circumstances, stress waves are consumed in the insert member. For this reason, the stress acting on the die and the punch is remarkably reduced, so that the life of the die and the punch is prolonged.
[0018]
In addition, because of this, the frequency of exchanging dies and punches is reduced, so that the frequency of stopping the operation of the forging apparatus is also reduced. That is, since the forging process can be performed continuously without stopping, the production efficiency of the molded product is greatly improved. Further, in this case, it is not necessary to purchase a large number of dies and punches, so that the purchase cost does not increase. As described above, the processing cost of the molded product can be greatly reduced.
[0019]
In addition, as a suitable constituent material of the insert member whose Young's modulus is in the above-described range, any of Ti, Ti alloy, Cu, and Cu alloy can be cited.
[0020]
Further, in order to sufficiently consume the stress, the thickness of the insert member may be set according to the thickness of the workpiece. Specifically, when the workpiece thickness exceeds 3 mm, the thickness of the insert member is 0.5 mm, and when the workpiece thickness is 1 to 3 mm, the thickness of the insert member is 0.5 to 2 mm. When the thickness is less than 1 mm, the thickness of the insert member is preferably 2 mm or more. Note that the thickness of the workpiece referred to here is a thickness on a surface that is sandwiched between the punch and the die and substantially orthogonal to the moving direction of the punch.
[0021]
Moreover, it is preferable that the side wall part of an insert member is curvedly formed. In this case, when the insert member is elastically deformed as the workpiece is forged, the insert member can smoothly slide on the upper end surface of the support plate and the lower end surface of the die. it can. Since there are no sharp corners on the side wall of the insert member, the side wall is caught by minute recesses or projections on the upper end surface of the holder and the lower end surface of the die when the insert member slides. This is because it is avoided.
[0022]
In the forging apparatus having the above-described configuration, a material made of a hard material having a Vickers hardness of 800 or more can be used for at least one of the die and the punch. As described above, in the forging apparatus according to the present invention, the stress acting on the die and the punch is small. Therefore, even a die or punch made of such a hard material can extend the life.
[0023]
In addition, in this case, the molding speed can be increased as compared with the forging apparatus of the prior art 1 described above. That is, the production efficiency of a molded product can be further improved.
[0024]
In addition, as a suitable example of a hard material, any of a cemented carbide, a cermet, or a gradient composite material in which the composition ratio of ceramics and metal changes from the surface to the inside can be given. Specific examples of these are as described above.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the forging apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. Components corresponding to those shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0026]
The principal part longitudinal cross-section block diagram of the forge molding apparatus which concerns on this Embodiment is shown in FIG. The forging apparatus 20 is for obtaining the molded product 10 shown in FIG. 5, and includes a die 22 and a support plate 5 disposed below the die 22, and includes a support plate 5 and a die 22. An insert member 24 is interposed therebetween (see FIG. 1). The holder 6 is externally fitted to the support plate 5 and the die 22 so that the support plate 5, the die 22 and the insert member 24 are mounted on the forging apparatus 20.
[0027]
In this case, the support plate 5 and the holder 6 are made of SKD61 material, while the die 22 placed on the support plate 5 is inclined in the same manner as the die ring described in Japanese Patent Laid-Open No. 2000-301279. Made of composite material. That is, the die 22 is a composite material containing a ceramic such as WC and a metal such as Co. As can also be understood from FIG. 2, which is a cross-sectional view taken along the line II-II in FIG. 1, the ceramic composition ratio in the die 22 is the surface side, that is, the outer wall portion side on which the holder 6 is fitted. And it is the highest at the inner wall portion side exposed to the cavity, the upper end surface and the lower end surface, and the center portion (inside) is the lowest. In contrast, the metal composition ratio is lowest on the surface side and highest in the interior. In other words, the ceramic rich portion 26 is formed on the surface of the die 22, and the metal rich portion 28 is formed inside. Further, between the ceramic rich portion 26 and the metal rich portion 28, there is an inclined portion 30 in which the ceramic composition ratio decreases from the ceramic rich portion 26 toward the metal rich portion 28 and the metal composition ratio increases. is doing.
[0028]
The inner wall portion and the outer wall portion of the die 22, that is, the Vickers hardness of the ceramics rich portion 26 is 1400 or more.
[0029]
Insert member 24 (refer to Drawing 1) is for relieving the stress which acts on die 22 and punch 4 at the time of forge processing. That is, as will be described later, most of the stress is consumed as the insert member 24 undergoes elastic deformation when forging a workpiece (not shown).
[0030]
As the insert member 24, one having a Young's modulus of 70 to 200 GPa is selected. If the Young's modulus is less than 70 GPa, buckling or breakage may occur during forging. On the other hand, if it exceeds 200 GPa, it becomes difficult to cause elastic deformation during forging, and it becomes difficult to relieve stress.
[0031]
Preferable examples of the insert member 24 satisfying such conditions include those made of Ti, Ti alloy, Cu or Cu alloy. An example of the Ti alloy is a Ti-6Al-4V alloy. Here, the Ti-6Al-4V alloy means a Ti alloy containing 6 wt% Al and 4 wt% V as constituent elements. On the other hand, examples of the Cu alloy include a Cu—Cr alloy and a Cu—Zn alloy called brass or brass.
[0032]
The constituent material of the insert member 24 may be selected depending on the molding load. For example, when the forming load is several tens of kN, the insert member 24 is preferably made of a material having a Young's modulus of about 120 GPa, such as Cu or a Cu—Cr alloy. Further, when the forming load is several tens to 100 kN, it is preferable that the Young's modulus such as Cu—Zn alloy is about 100 GPa, and when it exceeds 100 kN, the Young's modulus such as Ti or Ti alloy is 120 GPa. A thing of a grade is suitable.
[0033]
Furthermore, it is preferable that the thickness t of the insert member 24 shown in FIG. 3 which is an enlarged view of the main part of FIG. 1 is increased as the thickness of the workpiece is reduced. This is because the stress acting on the die 22 and the punch 4 during the forging process increases as the workpiece thickness decreases. That is, it is because it is necessary to increase the stress relieved by the insert member 24 as the workpiece thickness decreases.
[0034]
Specifically, when the workpiece has a thickness exceeding 3 mm, a thickness t of the insert member 24 of about 0.5 mm is sufficient. Moreover, what is necessary is just to let the thickness t of the insert member 24 be 0.5-2 mm in the workpiece | work whose thickness is 1-3 mm. In this case, needless to say, the insert member 24 may have a wall thickness t exceeding 2 mm. Furthermore, when the thickness of the workpiece is less than 1 mm, the thickness of the insert member 24 is preferably 2 mm or more.
[0035]
For example, when forming the molded article 10 having the shape shown in FIG. 5 by forging a workpiece made of an SCM420 tempered material having a thickness of 1 mm with a molding load of 180 kN, as the insert member 24, Ti-6Al— What consists of 4V alloy should just be selected, and the wall thickness t should be 1 mm.
[0036]
Here, a clearance 32 is provided between the insert member 24 and the holder 6 at a predetermined interval w. Further, the side wall portion of the insert member 24 is curved.
[0037]
In such a configuration, the holder 6, the insert member 24 and the die 22 are formed with a through hole 7, and a knockout pin 8 connected to a first drive mechanism (not shown) is inserted into the through hole 7. ing.
[0038]
On the other hand, the punch 4 is made of powdered high-speed steel and is connected to a second driving device (not shown).
[0039]
The main part of the forging apparatus 20 according to the present embodiment is basically configured as described above. Next, the function and effect will be described.
[0040]
The forging process using the forging apparatus 20 is performed as follows.
[0041]
First, the workpiece is placed in the cavity 2 with the punch 4 being separated from the die 22. Next, the second drive mechanism is energized to lower the punch 4 and insert it into the cavity 2. Along with this, the workpiece is pressed by the punch 4 while being supported from the die 22, and as a result, the workpiece undergoes plastic deformation. That is, the outer shape corresponds to the shape of the cavity 2 and the inner shape corresponds to the shape of the punch 4.
[0042]
As this pressing force is applied, a reaction (stress) occurs from the workpiece. However, most of this stress is consumed in the insert member 24, which is relatively soft and elastic. For this reason, of the generated stress, the component force acting on the die 22 and the punch 4 is remarkably reduced. In short, the insert member 24 itself undergoes elastic deformation when stress is generated, thereby reducing the stress acting on the die 22 and the punch 4. In other words, the insert member 24 performs a stress relaxation action.
[0043]
As described above, since the stress acting on the die 22 and the punch 4 is remarkably reduced by the stress of the insert member 24 being reduced, the life of the die 22 and the punch 4 is prolonged. Specifically, both can use up to about 810,000 shots.
[0044]
That is, by inserting the insert member 24 between the support plate 5 and the die 22, the life of the punch 4 and the die 22 is about 8.1 times that of the die and punch of the prior art 1 and the die of the prior art 2. About 4 times as long as the punch 4 and about 26.7 times as long as the punch 4. For this reason, since the replacement frequency of the die 22 or the punch 4 is remarkably reduced, the frequency of stopping the operation of the forging apparatus 20 is inevitably reduced. In other words, since the forging process can be continued without stopping, the production efficiency of the molded product 10 is greatly improved. In addition, in this case, the purchase cost of the die 22 and the punch 4 does not increase. Therefore, the processing cost of the molded product 10 is significantly reduced.
[0045]
Furthermore, since it is not necessary to replace the die 22 and the punch 4 over a long period of time, it is possible to avoid variations in the dimensions of the molded product 10.
[0046]
In the end, in the forging device 20 according to the present embodiment, the life of the die 22 and the punch 4 is prolonged, so that the processing cost of the molded product 10 can be greatly reduced and the dimensional accuracy of the molded product 10 can be reduced. Can be secured.
[0047]
As described above, the clearance 32 is provided between the insert member 24 and the holder 6 at the interval w. For this reason, stress is not transmitted from the insert member 24 to the holder 6. Furthermore, the insert member 24 causes thermal expansion by transferring heat generated from the workpiece when the workpiece is forged. However, since the clearance 32 is provided, the thermal expansion is also prevented. Absent. Therefore, it is possible to avoid the thermal stress from acting on the insert member 24, and eventually, the insert member 24 can be prevented from being deformed.
[0048]
Further, since the side wall portion of the insert member 24 is curved, sliding of the insert member 24 with respect to the support plate 5 and the die 22 smoothly proceeds when thermal expansion or elastic deformation occurs. In the insert member 24 having such a configuration, since there is no acute angle portion on the side wall portion, when the slide member slides with respect to the upper end surface of the holder 6 and the lower end surface of the die 22, the insert member 24 exists on the upper end surface and the lower end surface. This is because the side wall portion is prevented from being caught by the minute concave portion or convex portion.
[0049]
As can be understood from the above, in the forging device 20 according to the present embodiment, the clearance 32 is provided between the insert member 24 and the holder 6 and the side wall portion of the insert member 24 is curved. The insert member 24 can easily undergo thermal expansion or elastic deformation. For this reason, the stress relaxation action is favorably performed.
[0050]
The obtained molded product 10 is pushed out of the cavity 2 by the knockout pin 8 displaced upward in FIG. 1 as the first drive mechanism is biased, and is thereby taken out from the forging molding apparatus 20. It reaches. At this time, the insert member 24 is restored to its original size.
[0051]
In the above-described embodiment, the forging apparatus 20 including the die 22 configured similarly to the die ring described in Japanese Patent Application Laid-Open No. 2000-301279 has been described as an example, but the present invention is particularly limited thereto. It may be a forging apparatus provided with a die made of cemented carbide or cermet. Moreover, the forging apparatus which a punch consists of a cemented carbide alloy, a cermet, or a gradient composite material may be sufficient. Of course, both the die and the punch may be made of a hard material as described above.
[0052]
Furthermore, the constituent material of the die 22 and the punch 4 is not limited to a hard material, and may be a general constituent material of a die and a punch such as powdered high-speed steel or SKD11 material. Even in such a case, the life of the die and the punch can be prolonged as compared with the die and the punch of the prior art 1.
[0053]
【The invention's effect】
As described above, according to the forging device according to the present invention, the insert member is interposed between the die and the support plate that supports the die from below, so that the forging process is performed on the workpiece. The stress acting on the die and punch when applying is significantly reduced. For this reason, since the life of the die and the punch is prolonged, the effect that the machining cost is greatly reduced and the variation of the dimension of the molded product can be avoided is achieved.
[Brief description of the drawings]
FIG. 1 is a vertical cross-sectional configuration diagram of a main part of a forging apparatus according to the present embodiment.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is an enlarged view of a main part of FIG. 1;
FIG. 4 is a vertical cross-sectional configuration diagram of a main part of a forging apparatus according to a conventional technique.
FIG. 5 is a schematic overall longitudinal sectional view of a molded product produced by the forging apparatus of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,20 ... Forging molding apparatus 2 ... Cavity 3, 22 ... Die 4 ... Punch 5 ... Supporting board 10 ... Molded article 24 ... Insert member 26 ... Ceramics rich part 28 ... Metal rich part 30 ... Inclined part 32 ... Clearance

Claims (5)

In a forging apparatus comprising: a die provided with a cavity; a holder externally fitted to the die; a support plate disposed below the die; and a punch inserted into the cavity.
An insert member that is slidably interposed between the die and the support plate, and whose side wall portion is spaced from the inner wall of the insertion portion of the holder ;
The insert member has a Young's modulus of 70 to 200 GPa and the side wall portion is curved .   The forging apparatus according to claim 1, wherein the insert member is made of Ti, Ti alloy, Cu, or Cu alloy.   3. The apparatus according to claim 1, wherein the thickness of the insert member is 0.5 mm when the thickness of the workpiece exceeds 3 mm, 0.5 to 2 mm when the thickness of the workpiece is 1 to 3 mm, A forging apparatus characterized by having a thickness of 2 mm or more when the wall thickness is less than 1 mm. The apparatus according to any one of claims 1 to 3 at least one of the punch or the die, forged and wherein the Vickers hardness of a hard material having more than 800. 5. The forging apparatus according to claim 4 , wherein the hard material is one of a cemented carbide, a cermet, or a gradient composite material in which the composition ratio of ceramics and metal changes from the surface to the inside.

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