JP2516148B2 - Plastic forming method for members with holes - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic working of a perforated member capable of eliminating defects such as a cutout generated on the outer circumference when a perforated member having a through hole formed in the center thereof is obtained by plastic working. Regarding the method.

[0002]

2. Description of the Related Art Conventionally, as a method of flattening both end faces of a member having the same sectional shape such as a cylinder, a prism, and a spur gear whose outer peripheral shape does not change in the axial direction, as shown in FIG.
The following are known.

That is, in this method, the die 1 is formed with a die hole 5 having a shape corresponding to the member 3 having the same cross section and formed of a spur gear shown in FIG.
After the raw material 7 smaller than the inscribed circle of the member 3 having the same cross-section is put therein, the raw material 7 is compression-molded by the punch 9 and the counter punch 11 fitted to one side and the other side of the die hole 5, By filling the die hole 5 with the material 7, the member 3 having the same cross-section as shown in FIG. 27 is formed.

However, in such a plastic working method for a member having the same sectional shape, the punch 9 and the counter punch 1 are used.
When the material 7 is compression molded by 1, the material is moved from the point closest to the material 7 to the farthest point, that is, as shown in FIG.
In the spur gear of No. 7, since the tooth bottom portion 13 is sequentially filled toward the tooth tip portion 15, it is difficult for the material to reach the tooth tip portion 15, and as shown in FIG. There has been a problem that the thin portion 17 is generated at both ends of the outer periphery of the shaped member 3.

If a high stress is applied to the raw material 7 in order to reduce the thickness lacking portion 17, the stress on the die 1 may increase and the die 1 may be damaged. The spring back causes a large local variation when it is opened, making it difficult to reliably transfer the accuracy of the mold to the accuracy of the product.

Further, in this method, since it is necessary to fit the punch 9 and the die 1, there is a problem that vertical burrs are generated in the fitting portion 19. Furthermore, in this method, when trying to form a helical grooved tooth formation, such as a helical gear, it is necessary to fit the die while rotating the punch. There was a problem that it became extremely difficult.

The above-mentioned problem also occurs when the mandrel 21 is inserted in the central portion of the material 7 to form the hollow holed member 23, as shown in FIG. Therefore, as a method of plastically processing such a holed member 23, as shown in FIG. 29, the die portion 1A and the container portion 25 are urged toward the punch 9A side by the urging member 27, and the die portion 1A and the container portion 25 are urged. The material 7 put in the part 25 is
A plastic working method of a perforated member is considered in which the punch 9A that is in close contact with the upper surface of the die portion 1A pushes the material 7 together with the die portion 1A toward the counter punch 29 and compresses the material 7 by the punch 9A and the counter punch 29.

In this method, since it is not necessary to fit the punch 9A and the die portion 1A, vertical burrs do not occur in the fitted portion, and the tooth forming profile is twisted like a helical gear. It becomes possible to form a grooved material relatively easily.

[0009]

However, in such a plastic working method for a holed member, as shown in FIG. 29, the recessed portion 1 is formed at both ends of the outer periphery of the formed holed member 23.
There is a problem that 7 still occurs.

If a high stress is applied to the material 7 in order to reduce the thickness of the deficient portion 17, the stress on the die portion 1A increases, and the die portion 1A may be damaged. When the product is taken out, the spring back causes a large local variation, which causes a problem that it becomes difficult to reliably transfer the accuracy of the mold to the accuracy of the product.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a plastic working method for a perforated member capable of reliably preventing the occurrence of defects such as undercuts.

[0012]

A first method of plastic working a perforated member according to the present invention is to provide a die part in which a die hole having a shape corresponding to the perforated member to be obtained is formed and a continuous die part. Having a container part for holding the material, and inserting the material into a die member that is biased toward the punch side, and inserting the large diameter part of the mandrel into the through hole formed in the center of the material, and then fitting the material into the container part. The material is compression-molded by a counter punch that fits it and a punch that presses the end surface of the die member of the die member toward the counter punch, and the material is filled between the die hole and the large-diameter portion of the mandrel. Roughing step to obtain the material, after this roughing step, while applying compressive stress to the intermediate material by the punch and counter punch, while pulling out the large diameter portion of the mandrel from the through hole of the intermediate material, This Wherein to insert the small diameter portion of the mandrel into the through hole and has a finishing step of filling the material into the gap between the small diameter portion and the through hole of the mandrel.

A second plastic working method for a holed member according to the present invention has a die part in which a die hole having a shape corresponding to the holed member to be obtained is formed and a container part continuous with the die part. Then, after inserting the material into the die member that is urged toward the punch side, and inserting the small diameter part of the mandrel into the punch side of the through hole formed in the center of this material, the hole diameter following this small diameter part. After pressing the enlarged portion into the through hole and expanding the punch side of the through hole, a counter punch that fits into the container portion and a punch that presses the die portion end surface of the die member toward the counter punch side Is subjected to compression molding, and a roughing step of filling the material between the die hole and the mandrel to obtain an intermediate material, and after this roughing step, compressive stress is applied to the intermediate material by the punch and the counter punch. While working While pulling out the hole diameter enlarged part of the mandrel from the through hole of the intermediate material, the small diameter part of the mandrel is inserted into the through hole, and by the small diameter part of the mandrel, the tapered part, or the tapered part and the large diameter part. And a finishing step of filling the material with a gap between the enlarged through hole.

The third method of plastic working a perforated member according to the present invention comprises a die part in which a die hole having a shape corresponding to the perforated member to be obtained is formed, and a container part continuous to this die part. Then, while inserting the material into the die member that is biased toward the punch side, and inserting the small diameter part of the mandrel into the through hole formed in the center of the material, a counter punch that fits into the container part is provided. , A punch that presses the end surface of the die part of the die member toward the counter punch side, the material is compression-molded to fill the material between the die hole and the mandrel, and then the small diameter part of the mandrel is filled. Roughing step of press-fitting the following enlarged hole diameter portion into the through hole and expanding the punch side of the through hole to obtain an intermediate material, and after this roughing step, compressing the intermediate material with the punch and counter punch. Stressed While pulling out the hole diameter enlarged portion of the mandrel from the through hole of the intermediate material, insert the small diameter portion of the mandrel into this through hole, the small diameter portion of the mandrel, and the penetration enlarged by the hole diameter enlarged portion. And a finishing step for filling the material between the holes and the material.

[0015]

In the plastic working method for a holed member of the present invention, in the finishing step, compressive stress is applied to the intermediate material by the punch and the counter punch, and the large diameter portion of the mandrel or When the hole diameter enlarged portion is sequentially pulled out, the small diameter portion of the mandrel is sequentially inserted into the through hole, the material is sequentially filled in the gap between the small diameter portion of the mandrel and the through hole, and the material causes plastic flow as a whole, Plastic flow is likely to occur in another portion, and the intermediate material also plastically flows to the cutout portion side of the outer circumference of the intermediate material, and the cutout portion of the intermediate material is gradually filled from below.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 shows a plastic working apparatus used in the first embodiment of the method for plastic working a holed member according to the present invention. In the drawing, reference numeral 31 denotes a die member. There is.

The die member 31 includes a die portion 31a,
A container portion 31b continuous with the die portion 31a is formed. The die member 31 is biased upward by a spring 32.

The die portion 31a is formed with a die hole 35 having a shape corresponding to the holed member 33 composed of a helical gear shown in FIG. A through hole 36 is formed in the holed member 33.

Then, above the die portion 31a of the die member 31, a punch 37 capable of contacting the upper end surface of the die member 31 is provided.
Is arranged. The upper portion of the counter punch 39 is fitted into the container hole 31c of the container portion 31b of the die member 31.

A through hole 41 is formed in the counter punch 39, and a drive pin 43 is inserted under the through hole 41. On the other hand, the small diameter portion 47 of the mandrel 45 is inserted in the upper portion of the through hole 41.

The mandrel 45 has a small diameter portion 47 and a large diameter portion 4
The large diameter portion 49 is inserted into the punch 37. The mandrel 45 is biased toward the drive pin 43 side by the spring 51 arranged inside the punch 37.

The die member 31 is housed in the holder 52 so as to be vertically movable. Further, in this embodiment,
The upper end of the punch 37 is fixed to the upper holder 73 by the punch holder 71.

A through hole 37a is formed in the center of the punch 37, and a retaining portion 45a of the mandrel 45 is housed in the through hole 37a. A spring 51 is arranged between the retaining portion 45a and the upper holder 73, and a mandrel stopper 75 for restricting the upper end position of the mandrel 45 is arranged above the through hole 37a.

On the other hand, the lower holder 77 has a lower plate 79.
The holder 52 is fixed via. Lower plate 7
9, a through hole 79a is formed, and a hole 77a is formed in the upper portion of the lower holder 77.

A pin driving cylinder 81 is arranged below the hole 77a of the lower holder 77, and a hydraulic power source 83 is connected to the pin driving cylinder 81. A piston 85 is housed in the pin driving cylinder 81, and the lower end of the drive pin 43 is fixed to the upper end of the piston 85.

A second knockout plate 87 is arranged in the hole 77a of the lower holder 77, and a first knockout plate 89 is arranged in the through hole 79a of the lower plate 79.

A thrust bearing 91 is arranged on the upper surface of the first knockout plate 89. Then, the first knockout plate 89 and the second knockout plate 87 are connected by the first knockout pin 93.

The upper end of the second knockout pin 95 is fixed to the lower surface of the second knockout plate 87, and the second knockout pin 95 is arranged below the second knockout pin 95. It is configured to be vertically driven by a knockout device.

Using such an apparatus, the first embodiment of the plastic working method of the holed member of the present invention is performed as described below. That is, in this embodiment, first, as shown in FIG.
As shown on the left side of FIG. 1, a material 55 having a through hole 53, which is smaller than the inscribed circle of the holed member 33, is put into the die hole 35 of the die part 31a and the container hole 31c of the container part 31b. The large diameter portion 49 of the mandrel 45 is located in the through hole 53.

After this, the punch 37 is lowered and the punch 3
The lower end of the punch 37 is brought into contact with the upper end surface of the die member 31, and the lower end of the punch 37 is further lowered by the lowering of the punch 37.
It is abutted on the upper end surface of 5.

When the punch 37 is further lowered,
As shown on the right side of FIG. 1, the punch 37 and the counter punch 39 compression-mold the material 55, and the material 55 is plastically flowed to the die portion 31 a. At the same time, the die hole 35 and the large-diameter portion 49 of the mandrel 45 are formed. In the meantime, the material 55 is filled and the intermediate material 57 is obtained.

At this time, the intermediate material 57 includes the die portion 31a.
In, the lacking portion E is formed. Then, as shown on the left side of FIG. 3, while the compressive stress PP is applied to the intermediate material 57 by the punch 37 and the counter punch 39, the hydraulic pressure is supplied to the pin driving cylinder 81,
When the drive pin 43 is sequentially raised by raising the piston 85, the large diameter portion 49 of the mandrel 45 is sequentially pulled out from the through hole 59 of the intermediate material 57, and the small diameter portion 47 of the mandrel 45 is sequentially positioned in the through hole 59. , Through hole 59
And a small diameter portion 47 of the mandrel 45 forms a gap S.

Then, the intermediate material 57 is plastically flowed into the gap S, and the intermediate material 57 is also accompanied by the lacked portion E.
Plastic flow also occurs on the side, and the cutout portion E of the intermediate material 57 is gradually filled from below.

After that, as shown on the right side of FIG. 3, when the small diameter portion 47 of the mandrel 45 is positioned over the entire through hole 59 of the intermediate material 57, the molding is completed and there is no lacking portion E and both end surfaces are A flat perforated member 33 is obtained.

After completion of this finishing step, after the punch 37 is raised, the second knockout pin 95 is raised by driving a knockout device (not shown), as shown in FIG. The first knockout pin 93 is raised via 87, the counter punch 39 is supported by the thrust bearing 91, and the counter punch 39 which is rotatable is rotated along the twist of the holed member 33, Attached member 33
Is knocked out and taken out.

However, in the plastic working method of the holed member described above, in the finishing step, the punch 37 and the counter punch 39 exert a compressive stress on the intermediate material 57, and the mandrel through the through hole 59 of the intermediate material 57. Four
When the large-diameter portion 49 of 5 is sequentially pulled out, the small-diameter portion 47 of the mandrel 45 is sequentially inserted into the through hole 59.
In the gap S between the small diameter portion 47 and the through hole 59 of the intermediate material 5
7 are sequentially filled, and at this time, the intermediate material 57 is filled with the lacking part E.
Since the plastic material flows to the side as well, and the flesh portion E of the intermediate material 57 is gradually filled from below, it is possible to reliably obtain a perforated member having no defects such as flesh thickness.

(Second Embodiment) FIG. 5 shows a plastic working apparatus used in a second embodiment of the plastic working method for a holed member according to the present invention. A mandrel drive part 43a having the same diameter as the small diameter part 47 of the mandrel 45 is formed in the upper part, and the mandrel drive part 43a is formed in the lower part.
A knockout portion 43b having a larger diameter is formed.

Then, at the upper end of the knockout portion 43b,
A thrust bearing 91 is arranged. In the plastic working method using this device, as shown in FIG. 5, the drive pin 43A is moved to the first position by a knockout device (not shown).
Is moved upwards at a driving speed of
The small diameter portion 47 of the mandrel 45 is sequentially inserted into the mandrel 45, and the mandrel 45 is moved.

After the completion of molding, as shown in FIG. 6, the driving pin 43A is further raised by driving a knockout device (not shown), and the thrust bearing 91
Is abutted against the counter punch 39 and is supported by the thrust bearing 91 so that the counter punch 39 is rotatable.
Is knocked out and taken out while rotating along the twist of the holed member 33.

In FIG. 5, L ₁ indicates the amount of movement of the drive pin 43A for moving the mandrel 45, and in FIG. 6, L ₂ indicates the drive pin for knocking out the holed member 33. The amount of movement of 43A is shown.

(Third Embodiment) FIG. 7 shows a plastic working apparatus used in a third embodiment of the plastic working method for a holed member according to the present invention. In this apparatus, a large mandrel 45A is used. A taper portion 61 that connects the large diameter portion 49A and the small diameter portion 47A is formed between the diameter portion 49A and the small diameter portion 47A.

A mandrel press-fitting cylinder 97 is arranged in the upper holder 73, and the upper end of the mandrel 45A is connected to the piston 99 of the mandrel press-fitting cylinder 97.

Using such an apparatus, a third embodiment of the plastic working method for a holed member of the present invention is carried out as described below. That is, in the third embodiment, first, as shown on the left side of FIG. 7, in the die hole 35 of the die portion 31a and the container hole 31c of the container portion 31b,
A ring-shaped material 55 having a smaller outer diameter than the inscribed circle of the holed member 33 and in which the through hole 53 is formed is introduced.

The inner diameter of the through hole 53 is equal to that of the mandrel 4.
The outer diameter of the small diameter portion 47A of 5A is substantially the same as or slightly larger than the outer diameter of the large diameter portion 49A, and is sufficiently smaller than the outer diameter of the large diameter portion 49A.

Thereafter, the punch 37 is lowered while the mandrel 45A is urged by the piston 99 of the mandrel press-fitting cylinder 97 toward the container portion 31b.
The small diameter portion 47A of the mandrel 45A is the through hole 5 of the material 55.
3 after being inserted into the mandrel 45A, the taper portion 61
And the large diameter portion 49A is continuously press-fitted into the through hole 53, and the opening portion of the material 55 on the punch 37 side is expanded as shown on the right side of FIG.

Next, when the punch 37 is further lowered, the material 55A is compression-molded by the punch 37 and the counter punch 39, as shown on the left side of FIG.
Is plastically flowed to the die part 31a, and the material 55 is put in the die hole 35.
A is filled and the intermediate material 57 is obtained.

At this time, the intermediate material 57 includes the die portion 31a.
Is formed on the upper part of. Then, as shown on the right side of FIG. 8, after the pressure PP is applied to the punch 37 and compressive stress is applied to the intermediate material 57 by the punch 37 and the counter punch 39, the drive pin 4 is pressed.
When 3 is sequentially raised, the large diameter portion 49A and the tapered portion 61 of the mandrel 45A are sequentially pulled out from the through hole 59 of the intermediate material 57, the small diameter portion 47A of the mandrel 45A is sequentially positioned above the through hole 59, and the through hole 59 is formed. A gap S is formed between the small diameter portion 47A of the mandrel 45A and the small diameter portion 47A.

Then, the intermediate material 57 is plastically flowed into the gap S, and the intermediate material 57 is accompanied by the lacked portion E.
Plastic flow also occurs on the side, and the cutout portion E of the intermediate material 57 is gradually filled from below.

Even when a downward biasing force P is exerted on the mandrel 45A when the drive pin 43 is sequentially raised, if the upward force of the drive pin 43 exceeds this, the mandrel 45A moves upward. At times, by eliminating the downward biasing force of the mandrel 45A, the upward movement of the mandrel 45A becomes smoother.

Further, by eliminating the downward urging force of the mandrel 45A, the taper portion 61 is pressed by the downward compression force of the punch 37, depending on the shape and friction coefficient of the mandrel 45A, and the mandrel 45A naturally moves. In some cases, the mandrel 45A need not be raised by the drive pin 43 in this case.

Then, as shown on the left side of FIG. 9, when the small diameter portion 47A of the mandrel 45A is positioned over the through hole 59 of the intermediate material 57, the molding is completed,
A holed member 33 having no flattened portion E and having flat end surfaces is obtained.

After completion of this finishing step, the punch 37 and the counter punch 39 are raised, and the perforated member 33 formed into a predetermined shape is taken out. Also in the third embodiment, it is possible to obtain substantially the same effect as that of the first embodiment.

In the embodiment described above, the taper portion 61 and the large diameter portion 49A are inserted in the material 55, but the present invention is not limited to this embodiment and the taper portion 61 is used. Of course, it is also possible to insert only.

Further, the taper portion 61 may have a curved surface shape such as an arc shape. (Fourth Embodiment) FIG. 10 shows an essential part of a fourth embodiment of the plastic working method for a holed member according to the present invention. In the fourth embodiment, first, on the left side of FIG. As shown, in the die hole 35 of the die portion 31a and the container hole 31c of the container portion 31b, the ring-shaped material 55B having a smaller outer diameter than the inscribed circle of the holed member 33 and the through hole 53 is formed. It is thrown in.

After this, the small diameter portion 47A of the mandrel 45A.
Is inserted into the through hole 53A of the material 55B, and the punch 37
10, the material 55B is compression-molded by the punch 37 and the counter punch 39 without using the mandrel press-fitting cylinder 97, and the material 55B is plastically flowed to the die portion 31a. The material 55B is filled in the die hole 35.

Next, the mandrel 45A is attached to the container 3
The piston 9 of the mandrel press-fitting cylinder 97 is attached to the side 1b.
9, the taper portion 61 and the large diameter portion 49A of the mandrel 45A are continuously pressed into the through hole 53A, and as shown on the right side of FIG.
The diameter of the opening on the 7 side is expanded to obtain the intermediate material 55C.

Then, after that, the finishing step is performed in the same manner as shown on the right side of FIG. 8 and the left side of FIG. 9 to obtain the perforated member 33 formed in a predetermined shape. Also in the fourth embodiment, it is possible to obtain substantially the same effect as the other embodiments described above.

(Fifth Embodiment) FIG. 11 shows a plastic working apparatus used in a fifth embodiment of the method of plastic working a holed member according to the present invention. In this apparatus, the mandrel 45 has a large size. An escape portion 101 having a diameter smaller than that of the small diameter portion 47 is formed between the diameter portion 49 and the small diameter portion 47.

Further, a tapered approach portion 103 is formed below the relief portion 101. The plastic working method using this apparatus is carried out in substantially the same manner as in the first embodiment, but in this embodiment, it acts on the material 57 when the mandrel 45 on the left side of FIG. 12 is replaced. Due to the compressive stress, the material 57 once flows into the relief portion 101, and the fluidized material 57 is ironed and formed by the approach portion 103 and the small diameter portion 47.

Therefore, the hole portion 36 of the holed member 33 can be finished with higher accuracy. In this embodiment, as shown in FIG. 13, the relief portion 1 of the mandrel 45 is provided.
01 on the outer periphery of the small-diameter portion 47 in the axial direction.
By forming 5 and making it a cross section of an irregular shape such as a spline shape, it becomes possible to finish the spline hole or the like with high accuracy.

(Sixth Embodiment) FIG. 14 shows a plastic working apparatus used in a sixth embodiment of the method of plastic working a holed member according to the present invention. In this apparatus, a mandrel 45A is used.
Between the taper portion 61 and the small diameter portion 47A of the small diameter portion 47A.
An escape portion 101 having a smaller diameter is formed.

Further, a tapered approach portion 103 is formed below the escape portion 101. The plastic working method using this apparatus is carried out in substantially the same manner as in the third embodiment. However, in this embodiment, in the replacement state of the mandrel 45A on the right side of FIG. 15, the same as in the fifth embodiment. In addition, due to the compressive stress acting on the material 57, the material 57 once flows into the relief portion 101, and the flowing material 57 is
Since the small diameter portion 47A is formed by ironing, the holed member 3
The hole 36 of No. 3 can be finished with higher accuracy.

Then, as shown in FIG. 16, the holed member 33 is knocked out and taken out in the same manner as in the third embodiment. In the embodiment described above, the die member 3
The punch 3 is provided with a biasing member 32 including a spring.
Although the example of urging toward the 7 side has been described, the present invention is not limited to such an example, and for example, FIG.
As shown in FIG. 7, the urging force generating cylinder 107 is arranged on the upper surface of the lower holder 105, and the piston rod 1 is connected to the piston 109 of the urging force generating cylinder 107.
Needless to say, the die member 31 may be biased upward by 11.

In the above-described embodiment, the mandrel 45 is integrally formed with the large-diameter portion 49 and the small-diameter portion 47. However, the present invention is not limited to this embodiment. Of course, as shown in FIGS. 18 and 19, the large diameter portion 49B and the small diameter portion 47B may be separated at the boundary surface 113 thereof.

Further, in the above-described embodiment, the example in which the taper portion 61 and the small diameter portion 47A are integrally formed on the mandrel 45A has been described. However, the present invention is not limited to such an embodiment. As shown in FIG.
Of course, the taper portion 61 and the large diameter portion 45A may be formed by the dividing member 115, and the upper end of the small diameter portion 47C may be inserted into the dividing member 115.

In the embodiment described above, the die member 3
Although the example in which the die portion 31a and the container portion 31b are integrally formed in 1 has been described, the present invention is not limited to such an embodiment. For example, as shown in FIG. 21, the die portion 117 and the container portion 31b are formed. 119 may be formed separately, and further, the die part 117 is arranged in the lower holder 121, and the container part 119 is arranged in the upper holder 12.
Needless to say, it may be arranged in No. 3.

Further, in the above-mentioned embodiment, the example in which the holed member 33 having the boss portion formed on only one side of the tooth profile portion is formed is described, but the present invention is not limited to this embodiment. Instead, for example, as shown in FIG. 22, by forming the concave portion 125 at the tip of the punch 37, it becomes possible to form a holed member in which the boss portions 129 and 131 are formed on both sides of the toothed portion 127. .

Further, in the above-mentioned embodiment, an example in which the method of the present invention is applied to the plastic working of the holed member 33 made of a helical gear has been described, but the present invention is not limited to this embodiment. Alternatively, the holed member may be a cylinder, a triangular prism, a quadrangular prism, a hexagonal prism, or the like, or may be a spur gear, a bevel gear, or the like.

Further, the cross-sectional shape of the small-diameter portions 47, 47A of the mandrels 45, 45A is not limited to the circular shape, and it goes without saying that the cross-sectional shape may be a square shape, a hexagonal shape, a spline shape or the like. Further, in the plastic working method of the holed member of the present invention,
By heating the die member 31 and improving the lubrication condition, molding can be performed with lower stress, the life of the mold can be improved, and the dimensional accuracy of the product can be improved.

That is, FIG. 23 shows a helical gear 133 having one module, 23 teeth and a pitch cylinder twist angle of 20 degrees as shown in FIG. The average stress of 120 kg / mm ² is applied to the portion 135 to show the lack of tooth tip (A portion in the figure) when molding is performed while maintaining the die member 31 at room temperature. There was a substantially triangular cutout 137 of 5.5 mm and 0.06 mm in the axial direction.

On the other hand, FIG. 25 shows a state where the tooth tips (A portion in the figure) are thinned when the die member 31 is heated to 100 ° C. and molded under the same conditions. 0.0 in the radial direction
There was a recessed portion 139 of 5 mm and 0.015 mm in the axial direction, but this is almost negligible.

Incidentally, in order to reduce the thickness of the recessed portion 137 of FIG. 23 to the same size as the thickness of the recessed portion 139 of FIG. 25 with the die member 31 maintained at room temperature, an average stress of 160 kg is applied to the tooth portion 135. It was necessary to operate / mm ² .

[0073]

As described above, according to the plastic working method for a holed member of the present invention, in the finishing step, the intermediate material penetrates while the compressive stress is applied to the intermediate material by the punch and the counter punch. When the large diameter portion of the mandrel or the enlarged diameter portion of the mandrel is sequentially pulled out from the hole, the small diameter portion of the mandrel is sequentially inserted into the through hole, and the material is sequentially filled in the gap between the small diameter portion of the mandrel and the through hole. , The intermediate material also plastically flows to the flesh side, and the flesh portion of the intermediate material
Since it is gradually filled from below, there is an advantage that it is possible to reliably obtain a perforated member that is free from defects such as lack of thickness.

[Brief description of drawings]

FIG. 1 is a sectional view showing a plastic working apparatus used in a first embodiment of a plastic working method for a holed member of the present invention.

FIG. 2 is a top view showing a member with holes formed by the apparatus of FIG.

FIG. 3 is a cross-sectional view showing a finishing process using the apparatus of FIG.

4 is a cross-sectional view showing a knockout process by the apparatus of FIG.

FIG. 5 is a sectional view showing a plastic working apparatus used in a second embodiment of the method for plastic working a holed member of the present invention.

6 is a cross-sectional view showing a knockout process by the device of FIG.

FIG. 7 is a cross-sectional view showing a plastic working apparatus used in a third embodiment of the method for plastic working a holed member of the present invention.

8 is a cross-sectional view showing a finishing process with the apparatus of FIG.

9 is a cross-sectional view showing a knockout process by the apparatus of FIG.

FIG. 10 is a cross-sectional view showing a plastic working apparatus used in a fourth embodiment of the method of plastic working a holed member of the present invention.

FIG. 11 is a cross-sectional view showing a plastic working apparatus used in a fifth embodiment of the method of plastic working a holed member of the present invention.

12 is a cross-sectional view showing a finishing process with the apparatus of FIG.

13 is a cross-sectional view showing a small diameter portion in which a groove is formed in the device of FIG.

FIG. 14 is a sectional view showing a plastic working apparatus used in a sixth embodiment of the method for plastic working a holed member of the present invention.

FIG. 15 is a cross-sectional view showing a finishing process with the apparatus of FIG.

16 is a cross-sectional view showing a knockout process by the device of FIG.

FIG. 17 is a cross-sectional view showing an apparatus for urging the die member upward by the urging force generating cylinder.

FIG. 18 is a cross-sectional view showing an apparatus in which a large diameter portion and a small diameter portion of a mandrel are divided.

FIG. 19 is a cross-sectional view showing a finishing process using the apparatus of FIG.

FIG. 20 is a cross-sectional view showing an apparatus in which a tapered portion and a small diameter portion of a mandrel are divided.

FIG. 21 is a cross-sectional view showing an apparatus in which a die part and a container part are divided.

FIG. 22 is a cross-sectional view showing an apparatus for forming a holed member having boss portions formed on both sides of a toothed portion.

FIG. 23 is an explanatory diagram showing a cutout portion of a helical gear formed according to the first embodiment.

24 is a cross-sectional view showing the shape of the helical gear shown in FIG.

FIG. 25 is an explanatory view showing a cutout portion of a helical gear formed by heating a die member in the first embodiment.

FIG. 26 is an explanatory view showing a conventional plastic working method of a member without holes.

27 is a top view showing a gear processed by the method of FIG. 27. FIG.

FIG. 28 is an explanatory view showing a conventional plastic working method for a member with holes.

FIG. 29 is an explanatory view showing another example of the conventional plastic working method for a holed member.

[Explanation of symbols]

 31 die member 31a die part 31b container part 33 hole member 35 die hole 37 punch 39 counter punch 45, 45A mandrel 47, 47A small diameter part 49, 49A large diameter part 53 through hole 55 material 57 intermediate material 61 taper part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-351 (JP, A) JP-A-1-104437 (JP, A) JP-A-1-104436 (JP, A) JP-A-1- 104438 (JP, A) JP 61-27137 (JP, A) JP 50-99940 (JP, A) JP 57-134230 (JP, A) Actual development 59-194347 (JP, U)

Claims (8)

(57) [Claims] 1. A die member that has a die portion having a die hole having a shape corresponding to the holed member to be obtained and a container portion that is continuous with the die portion, and is provided in a die member that is biased toward the punch side. After inserting the material, after inserting the large diameter part of the mandrel into the through hole formed in the center of the material, press the counter punch that fits into the container part and the die part end surface of the die member to the counter punch side. The material is compression-molded by a punch that is used to fill the material between the die hole and the large diameter portion of the mandrel to obtain an intermediate material, and after the roughing step, the intermediate material is While applying compressive stress by the punch and the counter punch,
While pulling out the large-diameter portion of the mandrel from the through-hole of the intermediate material, insert the small-diameter portion of the mandrel into this through-hole, the finishing process step to fill the material between the small-diameter portion of the mandrel and the through-hole A plastic working method for a member having a hole, comprising: 2. A die member having a die part having a shape corresponding to a holed member to be obtained and having a container part continuous with the die part, wherein the die member is biased toward the punch side. After inserting the material, after inserting the small diameter part of the mandrel into the punch side of the through hole formed in the center of this material,
After press-fitting the hole diameter enlarged part following this small diameter part into the through hole and expanding the punch side of the through hole, the counter punch that fits into the container part and the die part end surface of the die member are placed on the counter punch side. With a punch that presses, a material is compression-molded, and a rough processing step of filling the material between the die hole and the mandrel to obtain an intermediate material, and after the rough processing step, the intermediate material with the punch. While exerting a compressive stress with a counter punch, while pulling out the hole diameter enlarged portion of the mandrel from the through hole of the intermediate material, insert the small diameter portion of the mandrel into this through hole, the small diameter portion of the mandrel, and the A plastic working method for a perforated member, comprising: a finishing step of filling a material in a gap between the through hole enlarged by the enlarged hole diameter portion and the through hole. 3. A die member which has a die portion having a die hole having a shape corresponding to the holed member to be obtained and a container portion which is continuous with the die portion, and which is urged to the punch side. While inserting the material, after inserting the small diameter part of the mandrel into the through hole formed in the center of this material, the counter punch that fits in the container part and the die part end surface of the die member are placed on the counter punch side. By pressing the punch, the material is compression-molded, the material is filled between the die hole and the mandrel, and then a hole diameter enlarged portion following the small diameter portion of the mandrel is press-fitted into the through hole to penetrate. Roughing step of expanding the punch side of the hole to obtain an intermediate material, and after this roughing step, applying compressive stress to the intermediate material by the punch and the counter punch, from the through hole of the intermediate material. The above Insert the small diameter part of the mandrel into this through hole while pulling out the expanded diameter part of the mandrel, and fill the gap between the small diameter part of the mandrel and the through hole expanded by the expanded diameter part with material. A plastic working method for a member with holes, comprising: 4. The plastic working of the perforated member according to claim 2, wherein the mandrel is pulled out in the finishing step by pressing force from the intermediate material acting on the hole diameter enlarging portion. Method. 5. A relief portion having a diameter smaller than the outer diameter of the small diameter portion is formed between the small diameter portion of the mandrel and the large diameter portion or the hole diameter enlarged portion, and while pulling out the mandrel,
When inserting the small-diameter portion of the mandrel, the compressive stress acting on the mandrel causes the material to flow into the relief portion once, and the fluidized material is ironed by the small-diameter portion to form the inner diameter portion of the holed member. The plastic working method for a holed member according to any one of claims 1 to 3, characterized by finishing. 6. A mandrel drive unit and a knockout unit are provided on the drive pin, and the mandrel is pulled out and the product is knocked out by operating the same knockout device in two steps. 3. The method of plastic working of a member with holes according to any one of 3 or 5. 7. The plastic working method for a holed member according to claim 1, wherein the die part and the container part are formed separately. 8. The plastic working method for a perforated member according to claim 1, wherein the die member is molded while being heated to a predetermined temperature.