JP2003053473A - Method for manufacturing approximately cylindrical forged goods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing excellent approximately cylindrical forged goods which is capable of reducing a material cost and working cost to a lower level and extremely simplifying working process steps. SOLUTION: In the method of obtaining the approximately cylindrical forged goods formed with holes and deformed to a cylindrical shape by plastically deforming a metallic columnar blank 3 in a die assembly 10 combined with a female lower die 11 and a male upper die 21, the male upper die 21 has a punch 22 which droops downward from the center of the bottom surface and has the same external diameter as the diameter of the hole formed at the metallic columnar blank 3 and a guide sleeve 23 which is inserted onto the root side of the punch 22 and has the same diameter as the external diameter of the metallic columnar blank 3. The punch 22 of which the front end face is flat only in the central part and of which the segment on the outer side is formed to a tapered surface inclining upward toward the circumferential edge is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a substantially tubular forged product which is wholly tubular or partially has a tubular portion.

[0002]

2. Description of the Related Art In a rotary drive unit of an electric washing machine, a bearing housing for rotatably holding a shaft and a connector for directly fixing an end of a shaft without a bearing as shown in FIG. Many shaped members are used.

This member is provided with a bottomed cylindrical portion 1 and a flange portion 2 which horizontally projects from the end edge of the bottom portion thereof, and usually the whole is cut out by cutting from a stainless steel round bar. It is manufactured by Alternatively, it can be obtained by cutting a round rod made of stainless steel into a predetermined length, applying a cold forging press to form the flange portion 2, and then cutting the other portion.

[0004]

However, the above-described manufacturing method has a problem that the material cost and the processing cost are high because the cutting allowance is large. Therefore, it is desired to manufacture not only the flange portion 2 but also a tubular portion by a cold forging press. However, in the tubular portion, unevenness in thickness is likely to occur in the peripheral wall. The accuracy of the coaxiality is poor, and after forging, the cutting process must be performed again to obtain the accuracy. In this case, it takes time and labor to process, and the processing cost cannot be reduced so much.

The present invention has been made in view of the above circumstances, and provides a method for manufacturing an excellent substantially cylindrical forged product which can keep the material cost and the processing cost low and can greatly simplify the processing process. Is its purpose.

[0006]

In order to achieve the above object, the present invention provides a method of plastically deforming a metal columnar material in a die formed by combining a female lower die and a male upper die to form a hole. Is a method of obtaining a substantially tubular forged product that is formed into a tubular shape and is formed into a tubular shape, and as the female lower die, at the center of the upper surface
Use the one having the hole whose outer diameter is the same as the outer diameter of the columnar material and the depth of which is set deeper than the height dimension of the columnar material.The male upper die is hung downward from the center of the lower surface. The punch has a punch having the same outer diameter as the hole diameter formed in the columnar material, and a guide sleeve fitted on the root side of the punch and having the same outer diameter as the columnar material. However, only the central part is flat, and the outer part is formed into a taper surface that is inclined upward toward the peripheral edge. The upper male die down from above, and push the punch downward from the upper surface of the cylindrical material while aligning the outer peripheral surface of the male upper die guide sleeve with the inner peripheral surface of the female lower die hole. By doing so, the inner peripheral surface of the hole of the female lower mold By utilizing the clearance of the punch peripheral surface, the preparation of substantially cylindrical forging which is adapted to form a cylindrical portion in the cylindrical element and the first aspect.

The present invention also provides a metal bottomed tubular member,
A method of obtaining a substantially cylindrical forged product in which the bottomed part is evenly deformed in the circumferential direction by plastically deforming in a mold formed by combining a female lower mold and a male upper mold, wherein the female lower mold is , A hole having the same diameter as the outer diameter of the tubular portion of the bottomed tubular member in the center of the upper surface, and the inner diameter of the tubular portion of the bottomed tubular portion which is coaxially fixed in the hole. A punch having an outer diameter is used, the tip surface of the punch is flat only in the central portion, and the outer portion thereof is formed into a tapered surface that is inclined downward toward the peripheral edge. The bottomed tubular member is mounted in the hole with the tubular portion fitted to the punch, and the male upper die is lowered from above, so that the bottomed tubular member is attached to the bottomed tubular member. The second gist is a method of manufacturing a substantially tubular forged product that is subjected to uniform plastic deformation in the circumferential direction.

Further, according to the present invention, the metal bottomed cylindrical member is plastically deformed in the mold formed by combining the female lower mold and the male upper mold, whereby the cylindrical portion is extended in the axial direction. A method for obtaining a substantially tubular forged product, wherein as the female lower die, a hole portion having the same outer diameter as the outer diameter of the tubular portion of the bottomed tubular member is provided in the center of the upper surface of the female lower die coaxially with the hole portion. And a punch having the same outer diameter as the inner diameter of the cylindrical portion of the bottomed cylindrical portion, the tip surface of the punch is flat only in the central portion,
The outer portion is formed into a taper surface which is inclined downward toward the peripheral edge, and the bottomed tubular member is fitted in the hole of the female lower die, and the tubular portion is fitted to the punch. In this state, the male upper die is lowered from above to utilize the gap between the inner peripheral surface of the hole portion and the outer peripheral surface of the punch of the female lower die to axially move the tubular portion of the bottomed tubular member. A third gist is a method of manufacturing a substantially tubular forged product that is extended in the direction.

Among these methods for manufacturing substantially cylindrical forged products, the diameter of the flat portion of the punch tip surface is set to 30 to 40% of the punch outer diameter, and the taper surface is inclined. A fourth gist is a manufacturing method of a substantially tubular forged product in which an angle is set to 6 to 8 ° with respect to a horizontal plane.

That is, according to the present invention, when manufacturing a substantially cylindrical forged product, a metal cylindrical body or a bottomed cylindrical body in which a part of the cylindrical portion is formed is used as a mold provided with a special punch. By compressing and plastically deforming inside, a cylindrical part is formed in the cylindrical body, the cylindrical part of the bottomed cylindrical body is extended in the axial direction, and the bottomed part of the bottomed cylindrical part is A substantially tubular forged product is obtained by applying some plastic deformation even in the direction. According to these manufacturing methods, since the tubular portion obtained by plastic deformation has highly accurate coaxiality, there is no need for cutting work, and material cost and working cost can be significantly reduced. And as a whole, there is an advantage that the process can be greatly simplified. Also,
Since the obtained product is a forged product, it has an advantage that it can be used in various applications in which the strength of the tubular portion is high and a load is easily applied, as compared with a machined product.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment in which the present invention is applied to manufacture a connector for holding a rotary drive shaft in a rotary drive section of a fully automatic electric washing machine will be described.

In this embodiment, the target connection
As shown in FIG. 1 (c), the kuta has a bottomed tubular portion 1 (bottom portion).
On the bottom edge of the
It has a shape in which the jeep portion 2 is extended. In addition, the above bottomed
The tubular portion of the tubular body 1 has an outer diameter D ₁Is 43 mm, inner diameter D₂But
It is 29 mm. Also, the bottom thickness T₁Is 11 mm,
Thickness T of flange 2₂Is 6.3 mm. Note that the cylinder
The depth T of the hole portion 4 provided in the groove portion is such that the bottom surface Ta is
Do not exceed the R start end U of the connecting portion between the flange portion 2 and the tubular portion.
It is preferable to do so. That is, the hole 4
If it is formed deeper than the R start end U, the flange 2
It may not be possible to form it on the ridge.

In the present invention, the connector is manufactured as follows.
The process is performed as shown in FIGS. 1 (a) to 1 (c). That is, first, as shown in FIG.
A columnar material 3 is prepared by cutting a 2.7 mm SUS403 bar to a length of 35.7 mm. Then, in order to provide lubricity to the surface of the cylindrical material 3,
Surface treatment is performed with a molybdenum-based treatment agent (so-called "black bonder treatment").

Next, this is loaded into the first mold,
For example, it is plastically deformed by cold forging with a press pressure of 400 tons (39.23 × 10 ³ MPa), and as shown in FIG. 1 (b), a hole 4 is formed to form a bottomed cylindrical body 3 ′. . Then, the bottomed tubular body 3'is loaded into a second mold, and plastically deformed by cold forging with a press pressure of, for example, 630 tons (61.78 × 10 ³ MPa), and then, as shown in FIG. The connector having the flange portion 2 as shown in FIG.

As the first die for making a hole in the columnar material 3, for example, a die 10 as shown in FIG. 2 is used. The female lower mold 11 of the mold 10 includes an inner cylinder 12 made of cemented carbide and nickel chrome molybdenum steel (SNCM).
An outer cylinder 13 and a guide ring 14 for centering,
Although it is extremely hard, it has a structure in which the inner cylinder 12 that is brittle and easily cracked is protected by a tough outer cylinder 13.

The inner diameter of the inner cylinder 12 is equal to that of the cylindrical material 3
The outer diameter of the columnar material 3 is set to be the same as the outer diameter of the columnar material 3, and a shaft portion 15 having the same diameter as the outer diameter of the cylindrical material 3 is coaxially inserted in the lower portion of the inner cylinder 12. Therefore, the upper end surface of the shaft portion 15 and the peripheral wall of the inner cylinder 12 form a hole for mounting the columnar material 3. However,
The above "same diameter" is not limited to the literal "same diameter",
It also includes a diameter of a dimension provided with a tolerance such that they can be fitted to each other, and the following "same diameter" is also used for the same purpose. After the end of the forging press, the shaft portion 15 is lifted to remove the cylindrical material 3 from the mold. Reference numeral 16 is a guide cylinder that guides the vertical movement of the shaft portion 15.

On the other hand, the male upper die 21 of the die 10 has the same outer diameter as the diameter of the hole formed in the columnar material 3, and has a punch 22 that hangs downward, and an outer fitting on the base side of the punch 22. A guide sleeve 23 having the same diameter as the outer diameter of the cylindrical material 3 and an outer cylinder 24 integrally holding these are provided.

The tip surface of the punch 22 is shown in FIG.
As shown in FIG. 5, only the central portion is flat, and the outer portion is formed into a tapered surface which is inclined upward toward the peripheral edge portion.
The diameter P of the flat portion 22a is set to 9 mm (0.3 when the outer diameter 28.8 mm of the punch 22 is 1).
1). The inclination angle Q of the tapered surface 22b with respect to the horizontal plane is set to 7 °.

The tip surface of the punch 22 has such a special shape that the male upper die 21 is lowered and the punch 22 is driven into the columnar material 3 to form the hole 4 (see FIG. 1). At this time, it is taken into consideration that accurate centering and uniform plastic deformation of the material in the circumferential direction can be performed. That is, when the tapered surface 22b is provided, the material can be uniformly moved in the circumferential direction and uniform plastic deformation can be realized. However,
When the tip surface of the punch 22 is sharpened in a conical shape, the punch 22
Is likely to enter the columnar material 3, but core runout is likely to occur. To prevent this, the flat portion 2 as in the above example is used.
It is necessary to provide 2a.

In order to obtain the above effect, it is preferable to set the inclination angle Q of the tapered surface 22b with respect to the horizontal plane to 5 to 10 °, especially 6 to 8 °. Also, the flat portion 2
It is preferable to set the diameter P of 2a to 20 to 50% of the outer diameter of the punch, especially 30 to 40%.

Further, in the guide sleeve 23 (returning to FIG. 2) fitted on the base side of the punch 22, the distance R between the lower end surface of the guide sleeve 23 and the lowermost end surface of the punch 22 is fitted into the female lower die 11. It is preferable to set the distance S between the upper end surface of the cylindrical material 3 and the upper end surface of the inner cylinder 12 by 10 to 14 mm. That is, when the male upper die 21 is lowered to drive the punch 22 into the cylindrical material 3 to form the hole 4, before the tip of the punch 22 reaches the upper surface of the cylindrical material 3, the guide sleeve 23 The lower part enters the inner cylinder 12 of the female lower die 11, and the peripheral surface of the guide sleeve 23 and the inner peripheral surface of the inner cylinder 12 of the female lower die 11 make sliding contact with each other.
This is because the center runout of the punch 22 is prevented.

Therefore, the female lower mold 11 of the mold 10 is
After inserting the columnar material 3 into the inner cylinder 12 of the above, as shown in FIG. 3, the male upper die 21 is lowered from above to move the punch 22 of the male upper die 21 into the central portion of the cylindrical material 3. Punched to form a hole 4, and the material portion extruded to the periphery is plastically deformed to form a uniform cylindrical portion between the inner peripheral surface of the inner cylinder 12 of the female lower die 11 and the outer peripheral surface of the punch 22. can do. At this time, as described above, since the tip end surface of the punch 22 has a special shape, and the punch 22 is driven while the center runout is prevented by the guide of the guide sleeve 23, the above-mentioned hole is formed. The formation of No. 4 is performed with very high accuracy and without center runout. Therefore, the tubular portion of the bottomed tubular body 3'obtained by forming the hole 4 has a uniform thickness in every portion, and the accuracy of coaxiality is high.

Then, by raising the male upper die 21 and raising the shaft portion 15 of the female lower die 11, the bottomed cylindrical body 3'having the hole 4 can be removed from the die.

Further, the cylindrical body 3'having a bottom has a structure shown in FIG.
As the second mold for shaping the flange portion 2 shown in, for example, a mold 30 as shown in FIG. 4 is used. The male upper mold 41 of the mold 30 has a flat lower end surface and is generally cylindrical. Further, the female lower die 31 is similar to the female lower die 11 of the first die 10 in that an inner cylinder 32 made of cemented carbide, an outer cylinder 33 made of nickel chromium molybdenum steel (SNCM), and a guide for centering. It has a structure including a ring 34.

The inner diameter of the inner cylinder 32 is set to be the same as the outer diameter of the bottomed cylindrical body 3 '. Inside the inner cylinder 32, the bottomed cylindrical body 3'is provided. A punch 35 having the same diameter as the inner diameter of the formed hole 4 is coaxially fixed.
A guide sleeve 36 having a flange portion 36a at the lower end is externally fitted to the base side of the punch 35, and four push-out pins 37 (two in front and rear are not visible) are provided below the guide sleeve 36. A push block 38 (see FIG. 5) is provided.

Therefore, the punch 35 and the peripheral wall of the inner cylinder 32 form a hole for mounting the bottomed cylindrical body 3'downward. The upper end surface of the guide sleeve 36 is set to have a slight gap with the lower end surface of the bottomed tubular 3'which is mounted in the punch 35 with the hole 4 fitted therein.

Further, like the punch 22 in the first die 10, the tip surface of the punch 35 is flat only in the central portion, and the outer portion thereof is formed into a tapered surface which is inclined downward toward the peripheral edge portion. ing. The punch 22 and the punch 35 are installed upside down,
Both are the same in shape.

The tip surface of the punch 35 is formed in such a shape as in the case of the punch 22, and the male upper die 41 is lowered to plastically deform the bottomed cylindrical body 3'to the bottomed portion. When the flange portion 2 is formed by applying the above, the prevention of center runout of the tubular portion of the bottomed tubular body 3 ′ fitted on the punch 35 and the uniform circumferential formation of the flange portion are taken into consideration. The operation is as described above, and the preferable range of the shape is the punch 2
Same as 2.

Therefore, as shown in FIG. 4, the hole 4 is punched 35 in the inner cylinder 32 of the female lower die 31 of the die 30.
After fitting the bottomed tubular body 3'with the bottomed portion of the bottomed portion plastically deformed by the flange portion 2 protruding from the upper end surface of the inner cylinder 32, as shown in FIG. Then, by lowering the male upper die 41 from above, the portion of the bottomed tubular body 3'protruding from the upper end surface of the female lower die 31 is crushed in the circumferential direction by the lower end surface of the male upper die 41. Plastic deformation can be given. At this time, as described above, the punch 3 provided in the knife lower die 31
5 has a special end surface, and even when the punch 35 receives an impact, the guide of the guide sleeve 36 prevents center runout, so that the flange portion 2 is evenly formed in the circumferential direction and has a tubular shape. Runout of the core is prevented.

Then, by raising the male upper die 41 and raising the push pin 37 of the female lower die 31, the bottomed cylindrical body 3'having the flange portion 2 can be removed from the die.

Then, the bottomed cylindrical body 3 ′ with the flange portion 2 is subjected to polishing finish processing to obtain a desired connector.

According to the above-mentioned manufacturing method, since the cylindrical portion (hole 4 forming portion) and the flange portion 2 obtained by plastic deformation have a highly precise coaxiality, there is no need for cutting,
Material costs and processing costs can be significantly reduced. And as a whole, there is an advantage that the process can be greatly simplified. In addition, since the obtained product is a forged product, the strength of the cylindrical portion and the flange portion 2 is higher than that of the machined one, and
The rotary drive shaft can be held well.

Although SUS403 is used as the columnar material 3 in the above embodiment, the material is not particularly limited to this, and SUS4 is used from the viewpoint of rigidity, toughness and the like.
Stainless steel such as 10 and various high-strength metals and alloys can be used.

Similarly, the materials of the respective members of the molds 10 and 30 can be appropriately selected depending on the material of the plastically deformable material, the pressing pressure and the like.

The configuration of the molds 10 and 30 is not limited to the above example, but may be any appropriate configuration. However,
The tip surfaces of the punches 22 and 35 for giving plastic deformation are
As in the above example, a special shape must be formed in which the central portion is flat and the periphery is tapered. Then, it is preferable to provide guide sleeves 23 and 36 on the root sides of the punches 22 and 35 in order to prevent core runout.

Further, in the above example, in order to obtain the connector, the step of forming the hole 4 in the columnar material 3 to form the bottomed cylindrical body 3 ', and the flange portion 2 on the bottomed cylindrical body 3'. However, the present invention may be a manufacturing method in which only one of the above-mentioned step and step is carried out. Further, according to the present invention, when performing plastic deformation from the bottomed tubular body 3 ′, a female lower die provided with the special punch 35 is used, and the bottomed portion is not limited to the formation of the flange portion 2 but the circumferential direction. It can also be applied to a method of shaping various uniform shapes.

Further, the present invention, as shown in FIG. 7, has holes 4 "(whether obtained by the forging method to which the present invention is applied or obtained by cutting). The bottomed tubular body 3 ″ having a shape in which the tubular portion is extended further in the axial direction by plastically deforming the material of the tubular portion from the bottomed tubular body 3 ″ along the outer circumference of the punch.
Can be applied to the method of obtaining.

Further, the present invention can be applied to obtain a complete tubular body 303 from the bottomed tubular body 302 by penetrating a punch as shown in FIG.
Furthermore, it is possible to obtain a perfect cylindrical body from the cylindrical material 3.

[0039]

As described above, according to the method for producing a substantially tubular forged product of the present invention, a cylindrical portion is formed in a cylindrical body by compressing a metal rod-shaped body in a mold and plastically deforming it. Or extending the tubular part of the bottomed tubular body in the axial direction or applying some plastic deformation evenly in the circumferential direction to the bottomed part of the bottomed tubular part to obtain a substantially tubular forged product. It is the one. According to these manufacturing methods, since the cylindrical portion obtained by plastic deformation has a highly accurate coaxiality, there is no need for cutting,
Material costs and processing costs can be significantly reduced. And as a whole, there is an advantage that the process can be greatly simplified. Further, since the obtained product is a forged product, it has an advantage that it can be used in various applications where the strength of the tubular portion is high and a load is easily applied, as compared with a machined product.

[Brief description of drawings]

1A, 1B, and 1C are process explanatory views of an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the first mold used in the above-described embodiment.

FIG. 3 is an operation explanatory view of the first mold used in the above embodiment.

FIG. 4 is an operation explanatory view of a second mold used in the above-mentioned embodiment.

FIG. 5 is an operation explanatory diagram of a second mold used in the above-described embodiment.

FIG. 6 is an explanatory diagram of a tip shape of a punch 22 in the first die.

FIG. 7 is a process explanatory diagram according to another embodiment of the present invention.

FIG. 8 is a process explanatory drawing in still another embodiment of the present invention.

FIG. 9 is an explanatory view of the shape of the connector.

[Explanation of symbols]

3 cylindrical material 10 First mold 11 female lower mold 21 Male upper mold 22 punch 23 Guide sleeve

Claims (4)

[Claims] 1. A substantially cylindrical forged product in which a hole is formed and is deformed into a tubular shape by plastically deforming a metal columnar material in a die formed by combining a female lower die and a male upper die. In the method, as the female lower mold, in the center of the upper surface,
Use the one having the hole whose outer diameter is the same as the outer diameter of the columnar material and the depth of which is set deeper than the height dimension of the columnar material.The male upper die is hung downward from the center of the lower surface. The punch has a punch having the same outer diameter as the hole diameter formed in the columnar material, and a guide sleeve fitted on the root side of the punch and having the same outer diameter as the columnar material. However, only the central part is flat, and the outer part is formed into a taper surface that is inclined upward toward the peripheral edge. The upper male die down from above, and push the punch downward from the upper surface of the cylindrical material while aligning the outer peripheral surface of the male upper die guide sleeve with the inner peripheral surface of the female lower die hole. By doing so, the inner peripheral surface of the hole of the female lower mold By utilizing the clearance of the punch peripheral surface, process for preparing a substantially cylindrical forging, characterized in that so as to form a cylindrical portion in the cylindrical material. 2. A substantially tubular shape in which a bottomed part is evenly deformed in the circumferential direction by plastically deforming a metal bottomed tubular member in a die formed by combining a female lower die and a male upper die. A method for obtaining a forged product, wherein, as the female lower die, a hole portion having the same diameter as the outer diameter of the tubular portion of the bottomed tubular member is coaxially fixed in the upper surface center thereof. A punch having the same outer diameter as the inner diameter of the tubular portion of the bottomed tubular portion, the tip surface of the punch is flat only in the central portion, and the outer portion is tapered downward toward the peripheral portion. Using the one formed on the surface, the bottomed tubular member is mounted in the hole of the female lower die with the tubular portion fitted to the punch, and the male upper die is lowered from above. By doing so, the bottomed portion of the bottomed cylindrical member is given uniform plastic deformation in the circumferential direction. A method for producing a characteristic tubular forging product. 3. A substantially tubular forging in which a tubular portion is axially extended by plastically deforming a metal bottomed tubular member in a die formed by combining a female lower die and a male upper die. A method for obtaining a product, wherein as the female lower die, at the center of the upper surface thereof, a hole having the same diameter as the outer diameter of the tubular portion of the bottomed tubular member, and coaxially fixed in the hole, A bottomed cylindrical portion having a punch having the same outer diameter as the inner diameter of the cylindrical portion, and the front end surface of the punch is flat only in the central portion, and the outer portion is a tapered surface inclined downward toward the peripheral portion. The bottomed tubular member is mounted in the hole of the female lower die with the tubular portion fitted to the punch, and the male upper die is lowered from above. By using the gap between the inner peripheral surface of the hole of the lower knife and the outer peripheral surface of the punch,
A method for producing a substantially tubular forged product, characterized in that the tubular portion of the bottomed tubular member is extended in the axial direction. 4. The diameter of the flat portion of the punch tip surface is set to 30 to 40% of the punch outer diameter, and the inclination angle of the taper surface is set to 6 to 8 ° with respect to the horizontal plane. The method for manufacturing the substantially tubular forged product according to claim 1.