JP2944465B2 - Method for manufacturing component having fine shaft portion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a component in which a thin shaft portion having a smaller diameter is forged at the tip of a large diameter portion.

[0002]

2. Description of the Related Art In the case of manufacturing a component having a small shaft portion smaller in diameter than a material diameter by forging and molding a material, a conventionally used manufacturing method is generally as shown in FIG.
The material 101 previously cut to a predetermined length is inserted into a molding die 130 having stepped forming holes 131 and 132, and the rear part of the material 101 in the molding die 130 is pressed by a pressing punch 135 to form the material. The tip of 101 is drawn. In particular, when manufacturing a component having a shaft portion smaller than the material diameter, a component having the shaft portion 104 whose tip is narrowed to a smaller diameter than the material diameter is used as the intermediate material 103, and this is used. A method of manufacturing a component having a thin shaft portion at the tip end by inserting it into a mold 140 as shown in FIG. 9 and pressing the rear portion of the intermediate material 103 has been considered.

[0003]

However, as described above, the front end of the material is subjected to the drawing process to form an intermediate material having the front end narrowed by a predetermined dimension, and the intermediate material is further subjected to the drawing process to have a shaft portion. When a part is formed, the material of the portion forming the fine shaft portion in the mold bulges due to the pressing force from the rear, so that a fine shaft portion of a predetermined dimension cannot be obtained at the tip. At present, in order to solve this problem, the shape of this mold has to be changed so that the material can flow easily, or if an accurate product shape is required, the shaft of the intermediate material obtained by drawing is required. At present, cutting is performed to reduce the diameter of the shaft portion to a predetermined size, thereby obtaining a product having a fine shaft portion at the tip. Therefore, the number of processing steps for obtaining this product increases, and the processing cost is high. Further, there is a problem that it is impossible to form a spherical surface between the large diameter portion and the fine shaft portion by ordinary forging.

[0004] A first object of the present invention is to solve such problems and to provide a manufacturing method capable of mass-producing such products with a simple structure.
Is to provide more accurate products,
A third object of the present invention is to provide a manufacturing method which simplifies the manufacturing process, and a fourth object of the present invention is to provide a method in which the material at the front end of the material flows smoothly toward the center during drawing and is stable. It is an object of the present invention to provide a manufacturing method capable of obtaining a finished product.

[0005]

SUMMARY OF THE INVENTION A first object of the present invention is to:
In a manufacturing method for manufacturing a large-diameter component having a small-diameter thin shaft portion at a tip, a raw material 1 previously cut to a predetermined size is used.
A hole 2 having a slight depth is forged at the tip of the material, and a material 1 having the hole 2 is formed in a molding die 30 having a molding hole 31 having a large diameter substantially equal to the material diameter and a molding hole 32 having a diameter smaller than the material diameter. To form an intermediate material 3 having a shaft portion 4 smaller than the material diameter by drawing at the tip of the material 1 and having stepped forming holes 41 and 44 set to the completed dimensions. This is achieved by inserting the intermediate material 3 that has been subjected to the drawing process into the finishing mold 40, and pressing the intermediate material 3 from behind to provide a manufacturing method of a component having a thin shaft portion for performing the finishing process. .

A second object of the present invention is as a drawing process.
The material 1 having the hole 2 formed at the tip is subjected to a first drawing to form a shaft 4 having a diameter smaller than the diameter of the material, and the shaft 4 is subjected to a second drawing. This is achieved by providing a multi-stage drawing process for forming a shaft portion thinner than the above thickness.

A third object of the present invention is to provide a manufacturing method for manufacturing a large-diameter component having a small-diameter thin shaft portion at the tip thereof. The raw material 1 cut to a predetermined size is inserted into a first forming die having a forming hole, and the leading end of the raw material 1 is subjected to drawing processing to form an intermediate raw material 3 having a shaft portion 4 smaller than the raw material diameter. A hole 2 having a small depth is formed in the shaft portion 4 of the intermediate material 3, and the intermediate material 3 is inserted into the shaping hole of the second molding die.
Is inserted first to form the intermediate material 3a, and the shaft portion 4 having the hole 2 is subjected to a narrower stepped shaft-shaped drawing process, and further, has stepped forming holes 41 and 44 set to the completed dimensions. Intermediate material 3a in which finishing die 40 has been subjected to the drawing process
This is achieved by providing a method of manufacturing a component having a fine shaft portion for performing finishing by pressing the intermediate material 3a from behind.

A fourth object of the present invention is to form spherical connecting surfaces 33 and 46 at stepped portions of stepped forming holes 31, 41, 32 and 44 of a mold, respectively, and connect them to a thin shaft portion. This is achieved by providing a method for manufacturing a component having:

[0009]

A hole 2 having a predetermined depth is formed by pressing a hole 2 having a predetermined depth in a hole making step 11 on the front end of the material 1 previously cut to a predetermined size in a cutting step 10. Thereafter, the material 1 in which the hole 2 is formed is inserted into the molding die 30 in the drawing step 12 with the hole 2 first, and a pressing force is applied to the rear part of the material 1 from behind. Since the connecting holes 33 having a spherical shape are formed in the stepped portions of the forming holes 31 and 32, the tip of the material 1 moves in the direction of shrinking the hole 2 by the action of the connecting surface 33 and the pressing force. Drawing is performed. Then, the tip narrows by this drawing, and the tip enters the small-diameter forming hole 32 of the mold 30.

When the material 1 advances in this way, the tip enters the forming hole 32 and the material 1 is formed by the spherical connecting surface 33 of the large-diameter forming hole 31, and the front end has a small shaft portion and a large diameter. An intermediate material 3 having a spherical surface formed at the tip of the portion is formed.

Thereafter, the intermediate material 3 is transferred to the next finishing step 13, where the shaft 4 at the tip is inserted into the forming holes 41 and 44 of the finishing mold 40 having dimensions as a product. Since it is pressed from behind, it is pressed into these forming holes 41 and 44 and deformed. This completes the product.

In a drawing step 12 for forming a thin shaft portion at the tip from the raw material 1, the drawing step 12 is defined as a first drawing process, and after the first drawing process for forming the shaft portion 4, In order to further squeeze the shaft portion 4 by the drawing process 2, the shaft portion 4 is pressed by applying a pressing force from the rear portion of the material 4 using a mold having a molding hole having a smaller diameter than the shaft portion 4. After that, by performing a molding operation as a product in the finishing step 13, a material with high accuracy can be obtained without cracks in the material 1.

Further, in the above operation, instead of forming the hole 2 in the raw material 1, an intermediate raw material 3 having a shaft portion 4 is previously formed at the tip of the raw material 1 by drawing, and thereafter, simultaneously with this operation, After the hole 2 having a predetermined depth is formed in the shaft portion 4, the intermediate material 3 is drawn again to make the shaft portion 4 thinner to obtain an intermediate material 3a. The intermediate material 3a on which the tip shaft portion 4 is formed is transferred to the next finishing step 13.
In this step, the shaft 4 at the front end is inserted into the mold 40 of the molding holes 41 and 44 having dimensions as a product.
It is pressed from behind and deformed. This completes the product.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows the deformation of the material 1,
Is a material. This material 1 is used in advance in a cutting process 10
Is cut to the required length to form the product. This material 1 proceeds to a drilling step 11 shown in FIG. As shown in FIG. 5, a guide die 20 having an insertion hole 21 for guiding the material 1 is disposed in the drilling step 11. Reference numeral 22 is disposed so as to be movable back and forth in the axial direction of the insertion hole 21. A guide member 23 for pushing out the material 1 in which the hole 2 is formed is inserted in the other same center line of the insertion hole 21 so as to be movable back and forth.

Following the drilling step 11, a drawing step 12 is arranged in the next step. The drawing step 12 is, as shown in FIG. 6, a material diameter for inserting the material 1 in which the hole 2 is formed. A molding die 30 having a large-diameter molding hole 31 having substantially the same diameter as the above and a molding hole 32 having a smaller diameter than the molding hole 31 is disposed. These large-diameter and small-diameter stepped molding holes 31 and 32 are provided in these molding holes. A spherical connection surface 33 is formed in this stepped portion. A guide member 34 for pushing the formed material 1 backward is inserted into the small-diameter forming hole 32 so as to be movable back and forth in the axial direction. 35 are provided.

Subsequent to the drawing step 12, the drawing step 1 is performed.
A finishing step 13 for shaping the intermediate material 3 formed as a product into a product is disposed for the intermediate material 3 formed in Step 2, and the finishing step 13 is, as shown in FIG. Is provided.
The finishing mold 40 is a split mold composed of a pair of molds divided in the axial direction of the raw material 1. One of the opposing molds has a molding hole 44 having a small diameter and a conical hole 45.
Are formed, and a spherical connecting surface 46 is formed continuously with the conical hole 45.

On the other hand, the other mold is provided with a molding hole 41 formed of a flange hole 42 and a large-diameter sliding hole 43 connected to the flange hole 42 on the side facing the mold. Further, a guide member 47 for extruding the product formed by the forging process in the finishing step 13 from the mold is inserted into the small-diameter forming hole 44 so as to be movable back and forth in the axial direction. Is provided with a pressing punch 48 that can move back and forth on the same center line. These large-diameter molding hole 41 and small-diameter molding hole 4
Numeral 4 is set to the finished dimensions of the product.

For this purpose, in the cutting step 10, as shown in FIG. 1, the raw material 1 is cut into a predetermined size in advance, and the cut raw material 1 is transferred to a drilling step 11 shown in FIG. After the material 1 is inserted into the insertion hole 21 of the guide die 20 in the drilling step 11, as shown in FIG.
2 is operated to form a hole 2 having a predetermined depth at the tip of the material 1. Thereafter, the raw material 1 in which the holes 2 are formed is removed by a drawing process 1
2 and forming holes 31 shown in FIG.
32, the material 1 is inserted with the hole 2 first.

In this state, when the rear part of the raw material 1 is pressed by the pressing punch 35, the front end of the raw material 1 is pressed into the forming hole 32 and the outer peripheral portion of the raw material 1 is deformed toward the center along the spherical connecting surface 33. To start. When the pressing punch 35 further advances in this way, the tip of the material 1 continues to deform in the center direction, and further, the material 1 enters the front small-diameter forming hole 32, and as shown in FIG. The stepped intermediate part 3 having the shaft part 4 is obtained.

After the intermediate material 3 is formed as described above, the intermediate material 3 is transferred to a finishing step 13 shown in FIG.
The shaft 4 is inserted into the forming holes 41 and 44 of the finishing die 40 shown in FIG. Then, the intermediate material 3 is
When the rear part is pressed, this intermediate material 3
5, the leading end of the large-diameter portion is pressed by a spherical connecting surface 46, and as shown in FIG. 1, the straight portion 5 is formed at the tip, and the tapered portion 6 and the tip are subsequently formed into a spherical shape. A product comprising the large diameter portion 7 is obtained.

FIG. 2 shows another embodiment of the present invention.
The drawing step 12 of the above embodiment is a step in which drawing processing is performed stepwise. In the first drawing processing, the tip of the material 1 is made smaller in diameter than the material diameter, and subsequently, the diameter of this material 1 is reduced. This is a so-called multi-stage drawing process in which a second drawing process is performed on the shaft portion 4 to form a fine shaft portion. Thereby, the shaft portion 4 can be reduced to a diameter of about 1/2 to 1/3 of the material diameter. By performing the drawing stepwise in this way, the flow of the raw material 1 becomes smooth, and a thinner shaft portion 4 can be formed. In particular, when forming the shaft portion 4 having the thin straight portion 5 at the tip and subsequently the tapered portion 6 as shown in FIG. 2, the product does not crack.

FIG. 3 shows another embodiment of the present invention. In the above embodiment, a hole 2
Was formed before drawing, but instead of this,
The material 1 cut to a predetermined size in the cutting process 10 is inserted into a first molding die having a stepped forming hole with a diameter smaller than the material diameter at the tip of the material 1 in the drawing process 12 and subjected to drawing, A hole 2 is formed at the tip of the shaft portion 4 that has been subjected to the drawing process to a small depth. The raw material 1 thus obtained is transferred to the drawing process as the next step again as the intermediate raw material 3, and the intermediate raw material 3 is inserted into the molding hole of the second molding die with the shaft portion 4 first. The portion 4 is drawn in a stepped shaft shape, and an intermediate material 3a having a small diameter shaft portion 4 is formed. Intermediate material 3a having shaft 4 formed in this way
In the finishing step 13 similar to that of the above-described embodiment, a finish process is performed to obtain a product similar to that of the above-described embodiment. In this embodiment, the shaft portion 4 of the final product has the tapered portion 6 so that the shaft portion 4 of the intermediate material 3a is a stepped shaft. 4 may be only the straight portion 5.

[0023]

As is apparent from the above-described embodiments, the present invention provides a method for manufacturing a component having a fine shaft portion at the tip thereof. The material 1 having the hole 2 is inserted into a molding die 30 having a molding hole 31 having a large diameter substantially the same as the diameter and a molding hole 32 having a diameter smaller than the material diameter. An intermediate material 3 having a thinned shaft portion 2 is formed, and the intermediate material 4 that has been subjected to the drawing process is inserted into a finishing mold 40 having stepped forming holes 41 and 44 set to complete dimensions. This is a method of manufacturing a part to be subjected to finishing, and also forms an intermediate material 3 having a shaft portion 4 smaller than the material diameter by performing drawing on the material 1 cut to a predetermined size. 4 is formed with a hole 2 having a small depth, A method for producing a component for performing finishing the intermediate material 3a obtained by applying the drawing again the material 3.

As described above, a hole is formed at the tip of the material, and thereafter, drawing is performed. Alternatively, after the material is drawn, a hole is formed at the tip of the shaft portion, and then drawing is performed again. Therefore, since the material flows smoothly toward the center, a shaft portion relatively thin with respect to the diameter of the material can be easily manufactured by forging. Further, by forming this hole in the material, the material does not swell in the gap between the material and the mold as in the related art during drawing. Further, since the need for forming a fine shaft portion at the tip of the material is eliminated by the cutting process, the number of processing steps is reduced, the processing cost is reduced, and an inexpensive product is obtained.

Further, since the drawing is performed in multiple stages, the flow of the raw material is ensured, and a highly accurate part can be obtained. In addition, since the spherical connecting surface is formed in the stepped part of the stepped forming hole of the mold, the material can be deformed so as to gather toward the center reliably, and the material will crack. There are no specific effects such as a beautiful surface.

[Brief description of the drawings]

FIG. 1 is a product process diagram showing a flow of a product as one embodiment of the present invention.

FIG. 2 is a product process chart showing a flow of a product as another embodiment of the present invention.

FIG. 3 is a product process diagram showing a flow of a product as another embodiment of the present invention.

FIG. 4 shows a manufacturing process of the present invention.

FIG. 5 is a cross-sectional view of a main part showing a drilling step of the present invention.

FIG. 6 is a sectional view of a main part showing a drawing step of the present invention.

FIG. 7 is a fragmentary cross-sectional view showing the finishing step of the present invention.

FIG. 8 is a sectional view of a main part showing a conventional example of drawing.

FIG. 9 is a sectional view of a main part showing another conventional example of drawing.

[Explanation of symbols]

 Reference Signs List 1 material 2 hole 3 intermediate material 4 shaft 5 straight part 6 taper part 7 large diameter part 10 cutting step 11 drilling step 12 drawing step 13 finishing step 20 guide die 21 insertion hole 22 forming punch 23 guide member 30 forming die 31 Large-diameter forming hole 32 Small-diameter forming hole 33 Connection surface 34 Guide member 35 Press punch 40 Finishing die 41 Large-diameter forming hole 42 Flange hole 43 Sliding hole 44 Small-diameter forming hole 45 Conical hole 46 Connection surface 47 Guide member 48 Press punch

Claims (4)

(57) [Claims] In a manufacturing method for manufacturing a large-diameter component having a small-diameter thin shaft portion at a front end, a hole 2 having a small depth is formed at a front end of a raw material 1 cut to a predetermined size, and a diameter of the raw material 1 is reduced. The material 1 having the hole 2 is inserted into a molding die 30 having a molding hole 31 having substantially the same large diameter and a molding hole 32 having a diameter smaller than the material diameter. The intermediate material 3 is formed by forming the intermediate material 3 having a thinner shaft portion 4 and further performing the drawing process on a finishing mold 40 having stepped forming holes 41 and 44 set to the completed dimensions.
And finishing the intermediate material 3 by pressing the intermediate material 3 from behind to perform a finishing process. 2. The drawing process is to perform a first drawing process on a material 1 having a hole 2 formed at a tip thereof to reduce the diameter of the material to a diameter smaller than the diameter of the material. 2. The method of manufacturing a component having a thin shaft portion according to claim 1, wherein the drawing process is a multi-stage drawing process in which a shaft portion 4 smaller than the thickness is formed by performing the drawing process. 3. A manufacturing method for manufacturing a large-diameter part having a small-diameter thin shaft portion at a tip thereof, wherein a first molding die having a molding hole having substantially the same diameter as the material diameter and a molding hole having a diameter smaller than the material diameter. The material 1 cut into a predetermined dimension is inserted into the shaft portion 4, and the leading end of the material 1 is subjected to drawing to make the shaft portion 4 thinner than the material diameter.
Forming an intermediate material 3 having
A hole 2 having a small depth is formed, and this intermediate material 3 is first inserted into the shaping hole of the second molding die with the shaft portion 4 formed therein to form an intermediate material 3a. Further, the intermediate material 3a subjected to the drawing process is inserted into a finishing die 40 having a narrow stepped shaft-shaped drawing process and having stepped forming holes 41 and 44 set to the completed dimensions. A method of manufacturing a component having a fine shaft portion, wherein the material 3a is pressed from behind to perform finishing. 4. The stepped forming hole of the mold is connected to the stepped portion by forming spherical connecting surfaces 33, 46 in the stepped portion. A method for producing a component having a fine shaft portion according to item 1.