JP2000079440A - Forging die device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a die by reducing distortion of the die due to stress and moreover to reduce the cost of the die. SOLUTION: This device is provided with an upper die 26 and a lower die 28 which form a cavity 24, a first to third inserting members 13, 15, 17 which externally fit the upper die 26 and the lower die 28 and which are divided in the axial direction and formed and a force-fitting ring 20 which externally fits the first to third inserting members 13, 15, 17. The hardness of the second inserting member 15 corresponding to a section where stress is concentrated on is set larger than the hardness of the first and third inserting members 13, 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forging die apparatus in which a forging material is provided in a cavity, and the forging material is forged under the action of a punch.

[0002]

2. Description of the Related Art Conventionally, a forging material is loaded into a cavity formed in an upper die and a lower die joined to each other, and a pressing force is applied to the forging material via a punch. There is known a mold apparatus for forging a sheet into a predetermined shape.

[0003]

In the case where a stepped component or a stepped gear is forged for a long period of time by using the above-described mold apparatus according to the prior art, a stepped portion of the stepped component or the like is formed. Stress concentrates on the inner wall surface of the mold in a direction substantially orthogonal to the axial direction, and the mold causes distortion (deformation) due to the stress. Therefore, there is an inconvenience that the life of the mold is shortened and the cost of the mold rises.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned disadvantages, and it is an object of the present invention to reduce the distortion of a mold due to stress, improve the durability of the mold, and reduce the cost of the mold. It is an object of the present invention to provide a possible forging die apparatus.

[0005]

In order to achieve the above object, the present invention provides an apparatus for forging by applying a pressing force to a forging material loaded in a cavity. A mold member to be formed, a plurality of annular bodies formed by externally fitting the mold members and divided in the axial direction, and a cylindrical member externally fitting the plurality of annular bodies. The hardness of the annular body corresponding to the portion where the stress is concentrated is set to be higher than the hardness of the other annular bodies.

[0006] In this case, the plurality of annular bodies include first to third insert members, and the hardness of the second insert member disposed in the middle in the axial direction is reduced by the hardness of the adjacent first and third insert members. It is preferable to set the hardness higher than the hardness.

According to the present invention, the hardness of the annular body corresponding to the portion where the stress is concentrated on the mold member is set to be higher than the hardness of the other annular bodies, and the rigidity in the radial direction perpendicular to the axis is secured. Therefore, distortion of the mold due to the stress is suppressed. As a result, the durability is improved as compared with the mold according to the related art.

Further, the present invention provides a mold member having a cavity in which a forging material is loaded, a plurality of annular bodies formed by externally fitting the mold member and being divided in the axial direction, A cylindrical member for externally fitting the annular body of the above, a punch for applying pressure to the forging material loaded in the cavity, and a punch mounted so as to surround a part of an outer peripheral portion of the punch, And a ring formed integrally with the mold member and having a hole into which the sleeve member is press-fitted when the punch applies a pressing force to the forging material. Wherein the hardness of the annular body corresponding to the portion where the stress is concentrated on the mold member is set to be higher than the hardness of the other annular bodies.

According to the present invention, the distortion of the mold due to the stress is suppressed, and the punch does not become misaligned in the lateral direction, so that the coaxial accuracy is maintained with high accuracy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a forging die apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 designates a forging die apparatus according to the present embodiment. The forging die apparatus 10 has a plurality of guide means 12a to 12a.
First die holder 14 on which 12d (see FIG. 4) is erected
And a second die holder 16 and a third die holder 18 provided at the center of the first die holder 14. A thick press-fit ring (cylindrical member) 20 is fixed on the second die holder 16 via a fastening means 22.

As shown in FIG. 3, a first insert member 13, a second insert member 15 and a third
The insert member 17 is integrally connected along the axial direction. In this case, the outer diameter of the first to third insert members 13, 15, 17 is set to be slightly larger than the inner diameter of the hole of the press-fit ring 20, and
The insert members 13, 15, and 17 are shrink-fitted into the holes of the press-fit ring 20 as described later. In addition,
The first to third insert members 13, 15, 17 are:
It functions as a plurality of annular bodies.

The first insert member 13 and the third insert member 17 are made of, for example, Rockwell hardness HRC.
The second insert member 15 is formed of, for example, a super hard material having a Rockwell hardness HRA of approximately 88. Therefore, the second insert member 15 is set to have a higher hardness than the first insert member 13 and the third insert member 17.

An annular convex portion 19 is formed at the lower portion of the inner peripheral surface of the press-fit ring 20, and the annular convex portion 19 and the annular concave portion 21 formed on the third insert member 17 are fitted to each other. The displacement of the three insert members 17 with respect to the lower side is regulated, and is positioned in the hole of the press-fit ring 20.

As shown in FIGS. 1 and 3, the fastening means 22 includes a fixing plate 27 that engages with the step of the press-fit ring 20 and a plurality of bolts 29 that hold the fixing plate 27 to the first die holder 14. And

The first to third insert members 13, 1
Inside the upper and lower dies 2, 5, 17 are formed.
The lower die 6 and the lower die 28 are integrally joined along the axial direction, and a cavity 24 in which a forging material is loaded is formed inside the upper die 26 and the lower die 28. The upper die 26 and the lower die 28 function as mold members.

In this case, the lower die 28 having the inner wall surface 23 corresponding to the connecting portion between the cup portion 86 and the shaft portion 88 of the outer cup, which is a forged product 84 (see FIG. 12), on which stress is concentrated during forging is formed. Since the outer insert is fitted by the annular second insert member 15 made of a harder material, the rigidity in the circumferential direction substantially perpendicular to the axis is enhanced. On the lower side of the outer peripheral surface of the lower die 28, an annular concave portion 25 that engages with the third insert member 17 is formed.

On the upper surfaces of the upper die 26 and the first insert member 13, as shown in FIG.
A first ring body (ring body) 34 having a hole 32 into which the press-fit ring 0 is formed is integrally joined.
A large-diameter second ring body 36 that is fitted to the first ring body 34 is integrally joined to the upper surface of the first ring body 34.

In this case, the second ring body 36 is fastened to the press-fit ring 20 so that the first ring body 34 is fitted to the outside, so that the tapered surface 38 formed on the second ring body 36 becomes the first ring body. Reverse tapered surface 4 formed on ring body 34
0, and a force acts to press the first ring body 34 downward.

An annular guide groove (not shown) for guiding the punch 30 when the punch 30 is press-fitted is formed in the upper portion of the hole 32 of the first ring body 34. One end of the punch 30 press-fitted into the hole 32 of the first ring body 34 has a desired uneven shape corresponding to the uneven shape of the product to be forged.

On the lower side of the cavity 24 formed by the upper die 26 and the lower die 28, a knockout pin 44 for extruding a forged product is formed along a hole 46 formed in the second die holder 16 and the third die holder 18. It is arranged to be able to move forward and backward. A secondary molded product 48 as shown in FIG. 11 is loaded into the cavity 24 as a forging material.

Above a predetermined distance from the press-fit ring 20, a ram (not shown) of a mechanical press (not shown) is connected, and is displaced vertically with the ram under the driving action of the mechanical press. An elevating member 50 is provided. The punch 30 is fixed to the elevating member 50 via a jig 52, and a guide sleeve (sleeve member) 54 formed of a cylindrical metal material is fitted on a predetermined portion of an outer peripheral portion of the punch 30. You.

As shown in FIG. 7, graphite 56 is buried in the guide sleeve 54 through a plurality of holes, and is lubricated when pressed into the holes 32 of the first ring body 34. Can be favorably maintained. In this case, the outer diameter of the guide sleeve 54 fitted to the punch 30 is set slightly larger than the inner diameter of the hole 32 of the first ring body 34.

The guide sleeve 54 is made of, for example, S
It is preferable that the first ring body 34 be formed of a material harder than the guide sleeve 54, such as a metal material such as KD11, FC25 or FC30.

The punch 30 is provided so as to be displaceable along the vertical direction integrally with the elevating member 50 under the guidance of a plurality of guide means 12a to 12d erected on the first die holder 14.

The guide means 12a (12b to 12d)
As shown in FIG. 5, a long post body 58 fixed to the first die holder 14, a cylindrical cover member 60 connected to the elevating member 50 and displaced integrally with the elevating member 50, A guide ring 64 provided so as to surround the outer peripheral portion of the post main body 58 and slidingly displaced along the axial direction of the post main body 58 by engaging with the annular step portion 62 of the cover member 60; And a spring member 66 that supports the spring 64.

A plurality of rows of holes 68 are formed in the guide ring 64 substantially in parallel along the axial direction.
A substantially cylindrical rolling member 70 is provided in the inside 8 so as to freely roll. As shown in FIG. 6, a flat first rolling surface 72 extending in the axial direction and formed in a plurality of substantially parallel rows is formed on the outer peripheral surface of the post body 58. A flat second rolling surface 74 facing the first rolling surface 72 is formed on the inner wall surface of the member 60.

In this case, the rolling member 70 rolls in line contact with the first rolling surface 72 and the second rolling surface 74, respectively, so that the cover member 60 connected to the lifting member 50 Guide ring 6 engaging with cover member 60
4 are integrally displaced along the axial direction of the post main body 58.

The guide ring 64 is not provided in the hole 68 of the guide ring 64, and the guide ring 64 is
8 may be formed so as to surround the outer peripheral surface, and the guide ring 64 may be formed to be relatively slidably displaced while making surface contact with the post body 58.

The forging die apparatus 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effect of the apparatus will be described. The following describes an example in which an outer cup forming a constant velocity joint is forged as a forged product.

First, the process of assembling the lower mold part of the forging die apparatus 10 will be described.

The third insert member 17, the second insert member 15, and the first insert member 13 are sequentially inserted along the axial direction of the hole of the press-fit ring 20. in this case,
Annular convex portion 19 of press-fit ring 20 and third insert member 1
The engagement with the annular concave portion 21 of 7 prevents the displacement of the third insert member 17 toward the lower side, and positions the third insert member 17 in the hole of the press-fit ring 20 (see FIG. 3).

Since the outer diameters of the first to third insert members 13, 15, 17 are set to be slightly larger than the inner diameter of the hole of the press-fit ring 20, the press-fit ring is heated via a heating means (not shown). 20 is heated and expanded, and the first to third insert members 13, 15 and 17 are inserted into the press-fit ring 2.
And fit into the hole of No. 0 by shrink fitting.

Subsequently, the first to third insert members 1
The lower die 2 extends along the axial direction of the holes 3, 15, and 17.
8 and the upper die 26 are sequentially inserted. In this case, the third concave portion 25 is formed on the outer peripheral surface of the lower die 28.
When the inner peripheral portion of the insert member 17 is fitted, displacement of the lower die 28 toward the lower side is regulated, and the insert is mounted in a positioned state (see FIG. 3). In addition, the lower die 28 includes the second and third insert members 15,
17 is strongly pressed into the hole.

Further, by mounting the first ring body 34 which engages with the upper die 26 and the upper surface of the first insert member 13, the second ring body 36 is fitted to the first ring body 34. , The second ring body 36
The tapered surface 38 formed on the first ring body 34 comes into sliding contact with the reverse tapered surface 40 formed on the first ring body 34, and a force acts to press the first ring body 34 downward. Due to this pressing force, the surface pressure of the joint surface between the upper die 26 and the lower die 28 increases, and the occurrence of burrs can be prevented.

In this case, the upper die 26, the lower die 28, the first to third insert members 13, The punch 30 is positioned with respect to the cavity 24 formed in the upper die 26 and the lower die 28 by integrally assembling the components 15, 17 and the like. Thus, the process of assembling the lower mold portion is completed.

Next, the forging process for the forging material will be described.

A cylindrical billet 7 as shown in FIG.
By performing the first forging on the mold 6 by a mold device (not shown), as shown in FIG. 9, primary molded products 78 having different diameters are obtained through the intermediate step. Subsequently, after performing the preliminary molding on the primary molded product 78 (see FIG. 10), the secondary forging is performed by another mold device (not shown) to obtain the primary molding 78 shown in FIG.
As shown in FIG. 1, the secondary molded product 48 including the cup portion 80 and the shaft portion 82 is obtained.

Forging die apparatus 10 according to the present embodiment
In this method, a third forging is performed using the second molded product 48 as a forging material.

First, as a preparatory operation, it is assumed that the punch 30 is previously positioned with respect to the cavities 24 formed in the upper die 26 and the lower die 28 in the above-described assembling process.

In a state where the punch 30 is arranged at a raised position (not shown), the cavity 24 is charged with a secondary molded product 48 as a forging material. Then, under the driving action of a mechanical press (not shown), the punch 30 descends integrally with the elevating member 50 connected to a ram (not shown), and forging is started when the state shown in FIG. 1 is reached.

When the punch 30 descends integrally with the elevating member 50, the elevating member 50 and the first die holder 14
A plurality of (e.g., four) guide means 12a to 12d provided between the first and second guide members 12a to 12d appropriately absorb the lateral eccentric load, and the punch 30 is smoothly pressed into the center of the first ring body 34.

When forging is started, the guide sleeve 54 fitted to a part of the outer peripheral surface of the punch 30 is formed into an annular guide groove formed at the upper end of the hole 32 of the first ring body 34 (see FIG. (Not shown), and the punch 30 descends, so that the punch 30 and the guide sleeve 54 are integrally displaced while being pressed into the hole 32 of the first ring body 34. .

In this manner, the punch 30 is lowered, and FIG.
2 from the forming start position shown in FIG. 2 to the forming end position shown in FIG. 2, forging is performed on the forging material via the punch 30, the lower die 28 and the upper die 26, and the forging is performed. The material plastically flows along the shape of the cavity 24.

After the forging is completed in this manner, the punch 30 is raised to a predetermined position integrally with the lifting member 50 connected to the ram (not shown) under the driving action of a mechanical press (not shown). Then, the punch 30 and the guide sleeve 54 are separated from the hole 32 of the first ring body 34, and are in a standby state for the next step. Then, the forged product 84 (see FIG. 12) is taken out under the displacement action of the knockout pin 44.

In this embodiment, the lower die corresponding to the portion where stress concentrates on the mold during forging, that is, the connecting portion between the cup portion 86 and the shaft portion 88 of the outer cup obtained as the forged product 84. Although the stress acts on the inner wall surface 23 of the lower die 28, the lower die 28 is externally fitted by the annular second insert member 15 made of a harder material, and the rigidity in the radial direction substantially perpendicular to the axis is secured. Therefore, distortion (deformation) of the mold due to the stress can be suppressed.

Therefore, even when forging is continuously performed for a long time using the forging die apparatus 10 according to the present embodiment, the life is prolonged as compared with the conventional die. , Durability can be improved. As a result, the cost of the mold can be reduced.

Further, when a pressing force is applied to the forging material, the guide sleeve 54 externally fitted to the punch 30 is in a state of being press-fitted into the hole 32 of the first ring body 34. The punch 30 descends while maintaining.

Therefore, in this embodiment, the punch 3 is inserted into the hole 32 of the first ring body 34 via the guide sleeve 54.
Since the pressing force is applied to the forging material in a state where 0 is press-fitted and the punch 30 does not become misaligned in the lateral direction, the outer cup obtained as a forged product 84 as shown in FIG. Axis E of the cup portion 86 and the shaft portion 88
Can be maintained with high accuracy in the coaxiality with the axis F. In this case, the deflection of the shaft portion 88 of the outer cup is
For example, it could be suppressed to 0.06 mm or less.

Further, the guide sleeve 54 and the first ring body 34 are each formed of a dissimilar metal material, and the graphite 5 embedded in the guide sleeve 54 is formed.
By maintaining good lubrication characteristics by the use of 6, it is possible to suppress the occurrence of galling on the sliding surfaces of the guide sleeve 54 and the first ring body 34.

Furthermore, by providing the guide sleeve 54 detachably with respect to the punch 30 via the jig 52, the guide sleeve 54 can be easily replaced with another new guide sleeve 54. There is.

In addition, for example, the outer peripheral surface of the cup portion 86 of the outer cup, which is the mounting portion of the pulsar (not shown), can be directly ground.

In the present embodiment, the outer cup constituting the constant velocity joint is used as a forging material, but the present invention is not limited to this. For example, a stepped part, a stepped gear or the like (not shown) may be used. It is needless to say that the present invention can be applied to various forged products requiring coaxial accuracy between a part of a part and another part.

[0054]

According to the present invention, the following effects can be obtained.

That is, the distortion of the mold due to the stress is reduced, the durability of the mold is improved, and the cost of the mold can be reduced.

Further, the coaxial accuracy of the obtained forged product can be maintained with high accuracy.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a forging die apparatus according to an embodiment of the present invention.

FIG. 2 is an operation explanatory view showing a state where a punch descends from a forging start position shown in FIG. 1 and forging is completed.

FIG. 3 is a partially enlarged longitudinal sectional view of the forging die apparatus shown in FIG. 1;

FIG. 4 is a partial cross-sectional plan view of the forging die apparatus shown in FIG.

FIG. 5 is an explanatory view of a guide means provided in the forging die apparatus shown in FIG.

FIG. 6 is a transverse sectional view taken along the line VI-VI in FIG. 5;

FIG. 7 is a perspective view showing a guide sleeve externally fitted to the punch.

FIG. 8 is an explanatory diagram showing a manufacturing process of an outer cup constituting the constant velocity joint.

FIG. 9 is an explanatory diagram showing a manufacturing process of an outer cup constituting the constant velocity joint.

FIG. 10 is an explanatory diagram showing a manufacturing process of an outer cup constituting the constant velocity joint.

FIG. 11 is an explanatory view showing a manufacturing process of an outer cup constituting the constant velocity joint.

12 is a longitudinal sectional view of a forged product forged by the forging die apparatus shown in FIG.

[Explanation of symbols]

10 ... Forging die apparatus 12a-12d ...
Guide means 13, 15, 17 ... insert member 14, 16, 18
... Die holder 19 ... Circular projection 20 ... Press-fit ring 23 ... Inner wall surface 24 ... Cavity 26,28 ... Die 30 ... Punch 32,46 ... Hole 34,36 ... Ring body 38 ... Taper surface 40 ... Reverse taper surface 50 ... Elevation Member 54: Guide sleeve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E050 FA01 FA03 FB03 FB06 FB07 FC01 4E087 AA08 AA09 AA10 CA11 CA31 EC11 EC12 EC22 EC37 EC41 EC46 ED22 ED25 ED28 ED31 ED33 HA21

Claims (3)

[Claims] An apparatus for forging by applying a pressing force to a forging material loaded in a cavity, wherein a mold member forming the cavity, and the mold member are externally fitted, and are axially oriented. A plurality of annular bodies formed by division; and a tubular member for externally fitting the plurality of annular bodies, wherein the hardness of the annular body corresponding to a portion where stress is concentrated on the mold member is determined by another annular body. A forging die apparatus characterized in that the hardness is set higher than the hardness of the forging die. 2. The device according to claim 1, wherein the plurality of annular bodies include first to third insert members, and the hardness of the second insert member disposed in the middle in the axial direction is equal to the hardness of the adjacent insert member. A forging die apparatus wherein the hardness is set to be larger than the hardness of the first and third insert members. 3. A mold member having a cavity in which a forging material is loaded, a plurality of annular bodies formed by externally fitting the mold members and being divided in an axial direction, and the plurality of annular bodies. A cylindrical member to be externally fitted, a punch for applying a pressing force to the forging material loaded in the cavity, and mounted so as to surround a part of an outer peripheral portion of the punch;
A sleeve member integrally displaced with the punch, and a hole formed integrally with the mold member, into which the sleeve member is press-fitted when the punch applies a pressing force to the forging material. And a ring body, wherein the hardness of the annular body corresponding to the portion where the stress is concentrated on the mold member is set to be higher than the hardness of the other annular bodies.