JPH0890135A - Joint metal tool and manufacture of this half-made product - Google Patents

Abstract

PURPOSE: To provide a fitting for piping which can efficiently be produced in the mass-production scale having extremely high productivity and yield, and a manufacturing method of a half finished product for manufacturing the fitting. CONSTITUTION: In a fitting 22 constituted of a head part 16 formed by cutting a sphere 10 to two surfaces with parallel planes 12 and forming a cavity part 14 in the inner part and a cylindrical shaft part 20 integrally extended from the head part 16 and provided with a hollow part 18 communicated with the cavity part 14, at least the cavity part 14 in the head part 10 and the hollow part 18 in the cylindrical shaft part 20 have the constitution integrally formed by forging formation. Further, the manufacturing method of half-made product for manufacturing such a fitting 22, the one end side of round columnar blank is forge-formed to almost half-spherical surface having the same diameter or a little smaller spherical diameter than the spherical diameter of the half-made product and on the other hand, the other end side of the round columnar blank is forge-formed to the outer diameter having almost the same diameter as the spherical diameter of the half-spherical surface and also, a rear part extruding formation is executed from the other end side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fitting for pipes used for fuel and lubricating oil pipes for automobiles, motorcycles, industrial machines and the like, and a method for producing the fitting, and more particularly to the fitting and an intermediate for producing the fitting. The present invention relates to a method of manufacturing a product.

[0002]

2. Description of the Related Art As shown in FIGS. 10 (a) and 10 (b), a joint fitting used for fuel or lubricating oil piping has a head in which a sphere is cut into two parallel planes and a cavity 100 is formed inside. Cylindrical shaft portion 1 including a portion 102 and a hollow portion 104 that integrally extends from the head portion 102 and communicates with the hollow portion 100.
And 06. This fitting is head 102
A fastening member having an oil passage is inserted into the hollow portion 100 of
For example, it is fastened to the machine body, and on the other hand, for example, a flexible pipe is fitted to the cylindrical shaft portion 106 to connect piping.

In such a joint fitting, as shown in FIG. 10 (a), in the case of the long joint fitting 108 of the cylindrical shaft portion 106, for example, a spherical body 110 and a solid shaft as shown in FIG. 11 (a) are used. The part 112 is manufactured by cutting or the like from an intermediate product 114 integrally formed. On the other hand, FIG. 10 (b)
As shown in FIG. 11, in the case of the short joint fitting 116 of the cylindrical shaft portion 106, for example, the spherical body 110 as shown in FIG.
Intermediate product 120 in which the hollow shaft 118 and the hollow shaft 118 are integrally formed
It is manufactured by cutting from.

Of these joint fittings 108 and 116, the joint fitting 10 having a long cylindrical shaft portion 106 shown in FIG. 10 (a) is used.
8 as an example, one example of the manufacturing method will be specifically described. First, as shown in FIG. 12 (a), the solid rod-shaped member 122 cut into an appropriate length is forged, and as shown in FIG. 12 (b), the solid shaft portion 112 is almost predetermined. In order to form the rod-shaped member 122 into a spherical shape without buckling, the head 124 is pre-installed in a substantially truncated cone shape. Next, the solid shaft 112 is fixed to the mold, and the head 124 is formed between the fixed mold and the movable mold formed on the substantially hemispherical surface.
Is forged to form a spherical body 110 and an intermediate product 114 is formed as shown in FIG. In order to mold the spherical body 110 into a substantially spherical shape, it is necessary to sufficiently perform centering between the fixed mold and the movable mold in all steps.
The preparation work was difficult and time-consuming.

The intermediate product 114 in which the sphere 110 is formed is
First, as shown in FIG. 2D, the spherical body 110 is cut into two parallel planes to form the head 102. This 2
The surface cut is formed by cutting, or trimming by a forging device and finishing by cutting. Then, as shown in FIG. 6E, a cavity 100 is formed in the head 102 by cutting, and then, as shown in FIG. 6F, a solid shaft 112 is cut by a drill. The hollow portion 104 is formed by. After that, the surface of the shaft portion 112 formed in a cylindrical shape is made uneven by cutting,
As shown in FIG. 10A, the cylindrical shaft portion 106 is formed, and the joint fitting 108 is manufactured.

[0006]

In the above-described method for manufacturing the joint fitting, it is difficult to form the intermediate product 114, especially the spherical body 110, by forging, as described above. Moreover, the solid glybite for machining the hollow internal cavity 100 from the solid sphere 110 of the intermediate product 114 has a low rigidity of the shank portion of the tool due to the characteristics of the shape of the product, and high-speed heavy cutting. Was impossible.
Therefore, a desired shape is formed by repeatedly cutting with a small cutting amount, which requires time. Further, the hole forming for forming the hollow portion 104 in the solid shaft portion 112 is performed by cutting with a drill, but this processing also requires a long time for cutting and is a low productivity method.

On the other hand, as shown in FIG. 11 (b), when the joint fitting 116 is manufactured from the intermediate product 120 integrally formed with the hollow shaft portion 118, the shaft portion 118 is formed with a hole by a drill. Although it is not necessary to apply, when forming the hollow portion 100 in the sphere 110 by cutting, the tip of the middle glybite is cut discontinuously in the hollow portion 104 of the shaft 118. Therefore, there is a problem that the tip of the medium glybite is easily damaged. Further, the hollow portion 1 is attached to the shaft portion 118.
There is also a problem that the punch for forming 04 is easily broken.

Therefore, the present inventor has conducted intensive studies for the purpose of providing a method for efficiently manufacturing a joint fitting on a mass production scale with extremely high productivity and yield, and as a result, the present invention has been achieved.

[0009]

SUMMARY OF THE INVENTION The gist of a fitting according to the present invention is that a spherical body is cut into two planes in parallel planes and a hollow portion is formed inside, and a head is integrally formed. In a joint fitting that is formed of a cylindrical shaft portion that has a hollow portion that extends into the hollow portion and communicates with the hollow portion, at least the hollow portion of the head portion and the hollow portion of the cylindrical shaft portion are integrally formed by forging. Is being done.

Next, the gist of the method for producing an intermediate product for producing a fitting according to the present invention is that one end side of a cylindrical material having a predetermined size has the same or slightly the same diameter as the spherical diameter of the intermediate product. Forged into a nearly hemispherical surface with a small spherical diameter, while
Simultaneously with or after press-forming the other end of the columnar material to an outer diameter substantially the same as the spherical diameter of the hemispherical surface, backward extrusion molding is performed from the other end to obtain one end of the hemispherical surface. The inside is forged into a hemispherical surface having a spherical diameter substantially the same as or slightly smaller than the inner diameter of the hollow portion of the head of the intermediate product, and has a wall thickness substantially the same as the wall thickness of the head of the intermediate product. A preforming step of forming the inside of the other end side into a cylinder having an inner diameter substantially the same as or larger than the inner diameter of the inner hemispherical surface, and an outer diameter of the cylindrical portion of the preformed material is a cylindrical shaft portion of an intermediate product. And a molding step of molding the hemispherical portion side of the material into a spherical body of a head of an intermediate product while molding the outer diameter of the material.

Further, in the method for manufacturing an intermediate product of such a fitting, in the forming step, a mandrel having an outer diameter substantially the same as the inner diameter of the hollow portion of the cylindrical shaft portion of the fitting is formed into a cylinder of the material. The shaft portion is provided inside by a draw forming portion having a hemispherical surface having a spherical diameter equal to that of the head of the intermediate product and a draw forming portion having an inner diameter equal to the outer diameter of the cylindrical shaft portion of the intermediate product. It is to shape the head into a spherical shape as well as to shape.

Further, in the method for manufacturing an intermediate product of such a fitting, the spherical head of the obtained intermediate product is trimmed so that two planes are cut by parallel planes which are substantially parallel to the axial direction of the cylindrical shaft. To do.

[0013]

The joint fitting according to the present invention is configured such that a hollow portion and a hollow portion are simultaneously formed inside the head portion and the cylindrical shaft portion which are integrally formed by forging. Therefore, the manufactured fitting has few places where it is cut, and the metal flow generated by forging flows from the head to the cylindrical shaft with almost no cutting, and the strength is greatly improved. . In addition, since machining such as cutting is hardly performed, manufacturing cost and time can be significantly reduced.

Next, in the method for manufacturing an intermediate product of a fitting according to the present invention, one end of a cylindrical material cut into a predetermined size is changed from a ball diameter substantially equal to that of the head of the fitting or the intermediate product. Is formed into a hemispherical surface, and the other end of the columnar material is press-formed into an outer diameter approximately the same as the spherical diameter of the hemispherical surface. Simultaneously with or after this forging, the columnar part that is the other end of the hemisphere is extruded backward, and the wall thickness on the hemispherical side is the same as the wall thickness of the joint fitting or the head of the intermediate product. A hemispherical cavity having a spherical diameter that is approximately equal to or slightly thicker and has a spherical diameter that is approximately equal to or slightly smaller than the spherical diameter of the spherical cavity that is formed inside the head, and , The other end is formed into a cylinder. Then, the material preformed in this way is drawn from the cylinder at the other end to the dimension of the cylindrical shaft portion of the intermediate product, and at the same time, the space between the hemispherical surface and the cylinder is formed into a hemispherical surface. To mold. This allows
A spherical hollow portion is formed inside the spherical body, and a cylindrical shaft portion having a hollow portion is formed from the cylinder at the other end.

Further, in the method of manufacturing such an intermediate product,
By arranging a mandrel in the center of the draw forming part of the inner diameter, and by squeezing out the cylinder of the preformed material in the space formed by the draw forming part of the inner diameter and the mandrel,
It is possible to obtain a cylindrical shaft portion in which not only the outer diameter but also the inner diameter is formed uniformly.

Further, in the method of manufacturing such an intermediate product,
By cutting the spherical head of the obtained intermediate product on two sides by trimming, the subsequent cutting can be greatly reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a method for manufacturing a joint fitting and an intermediate product thereof according to the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1 (a) and 1 (b), the joint metal fitting according to the present invention has a head 16 in which a sphere 10 is cut on two parallel planes 12 and a cavity 14 is formed therein, and a head 16 thereof. And a cylindrical shaft portion 20 having a hollow portion 18 which extends integrally from the head portion 16 and communicates with the hollow portion 14,
In this joint fitting 22, at least the hollow portion 14 of the head portion 16 and the hollow portion 18 of the cylindrical shaft portion 20 are integrally formed by forging. That is, the joint fitting 22 is formed integrally with the hollow portion 14 and the hollow portion 18 at the same time that the head portion 16 and the cylindrical shaft portion 20 are formed by forging, instead of being formed by a processing method such as cutting. Has been done.

Since the cavity 14 and the cavity 18 are formed by forging in the joint metal fitting 22 having such a structure, not only the man-hour of cutting work is greatly reduced, but also the consumption of cutting tools such as a bite and a drill is reduced. In addition, the cost and time required for manufacturing the joint fitting 22 can be significantly reduced, because the consumption of material is reduced. Moreover, the fitting 2
Since the hollow portion 14 and the hollow portion 18 are not cut in No. 2, the so-called metal flow flows from the head portion 16 to the cylindrical shaft portion 20, and the strength of the joint fitting 22 is significantly improved.

The intermediate product of the joint metal fitting 22 according to the present invention is manufactured through the basic steps shown in FIG.
First, a solid rod-shaped member having a predetermined diameter and a circular cross section is used, and a columnar material 24 having a predetermined length is cut out from this rod-shaped member as shown in FIG. Next same figure
As shown in (b), one end of this columnar material 24 is forged into a hemispherical shape 26, and the other end is forged into a columnar shape 28 having a diameter substantially the same as the spherical diameter of the hemispherical shape 26. This processing can be carried out, for example, by using a combination of forward extrusion and upsetting in a mold. In addition, in this processing step, when the end surface 30 of the cut columnar material 24 is not flat, at the same time as forming one end into the hemispherical shape 26,
The end face 30 at the other end is flattened.

Next, as shown in FIG. 3C, a hollow bottomed material 3 having a hemispherical surface 32 at one end and a cylindrical shape 34 at the other end.
Mold 6. That is, for the hollow material with a bottom 36, the cylindrical material 38 shown in FIG. 1 (b) whose one end side is formed on the hemispherical surface 26 is the spherical diameter of the head 16 of the joint fitting 22 which is a finished product or its intermediate product. While being loaded into a mold having a mold formed on a substantially hemispherical surface (32) having the same diameter as or a slightly smaller spherical diameter, the material 3 in the mold by pressing the punch from the other end side.
It is obtained by extruding 8 backward. The molded bottomed hollow material 36 has a hemispherical surface 40 having a spherical diameter substantially the same as or slightly smaller than the inner diameter of the cavity portion 14 of the product head 16 at the one end side of the hemispherical surface 32. A hollow portion is formed by forging into a thickness substantially the same as the thickness of the head portion 16 and the inside of the cylindrical shape 34 on the other end side of the bottomed hollow material 36 has a diameter substantially equal to or larger than the inner diameter of the hemispherical surface 40. 42 is obtained by forging.

Thereafter, as shown in FIG. 3D, the cylindrical portion 34 of the bottomed hollow material 36 is drawn to form a cylindrical shaft portion 44, and at the same time, between the hemispherical surface 32 and the cylindrical shaft portion 44. Is formed on the hemisphere surface 46, and the hemisphere surface 32 and the hemisphere surface 46 form the sphere 10. The cylindrical shaft portion 44 is formed with an outer diameter suitable for forming the cylindrical shaft portion 20 of the joint fitting 22 by cutting the outer surface, and the hollow portion 42 is accordingly formed into a hollow portion of the joint fitting 22 which is a finished product. The inner diameter of the portion 18 is approximately equal to the inner diameter of the portion 18. On the other hand, inside the spherical body 10, a substantially spherical cavity portion 14 is formed by a previously formed hemispherical surface 40 and a hemispherical surface 48 formed inside the hemispherical surface 46 formed by drawing. ing. It should be noted that the spherical body 10 and the spherical cavity portion 14 can be obtained as a substantially spherical body by the positioning of the fixed die and the movable die and the centering. In this way, the intermediate product 50 for manufacturing the joint fitting 22 is manufactured by forging.

Here, as shown in FIG. 3C, in the inner surface shape of the hollow material 36 with a bottom, the inner diameter of the hollow portion 42 at the other end is larger than the inner diameter of the hemispherical surface 40 at the one end. Is preferably made larger and a shape in which a smooth taper 52 is connected between them is preferable.

First, in determining the spherical diameter of the spherical body 10, the wall thickness of the head 16 of the joint fitting 22 determines the inside and outside diameters of the sphere in this step, and ideally, the head 16 of the joint fitting 22. It is preferable that the sphere has the same size as the sphere outer diameter. Next, the outer diameter of the cylindrical shape 34 on the other end side is the same as the outer diameter of the sphere, and the inner diameter of the cylindrical shaft portion 4 is reduced in the next step.
It has a close relationship with the inner and outer diameter dimensions of No. 4, and during the drawing process in the process shown in Fig. 4 (d), there is no abnormal burr on the outer diameter portion of the ball, and the inner diameter portion of the ball is not deformed due to buckling. It is necessary to have such a size that the cylindrical shaft portion 44 can be squeezed out smoothly, that is, the cross-sectional reduction rate is 50% or less. Further, the purpose of joining the inner diameter portion joining the hemispherical surface 40 and the hollow portion 42 with the smooth taper 52 is to form the cylindrical shaft portion 44 by the drawing process in the next step, and then join the hemisphere surface 4
This is because, when 6 is formed by drawing, it is necessary to gradually change the wall thickness so that the wall thickness of the sphere sandwiched by the hemispherical surface 46 and the inner hemispherical surface 48 is as uniform as possible. .

The intermediate product 50 for manufacturing the joint metal fitting 22 may be manufactured by forging, and then the joint metal fitting 22 may be manufactured by cutting, as shown in FIG. As shown in e), the intermediate portion for manufacturing the joint metal fitting 22 is manufactured by so-called trimming at the time of forging, by cutting two surfaces of the spherical body 10 with parallel planes 54 parallel to the axial center direction of the cylindrical shaft portion 44. It may be the item 56. By cutting the two surfaces with the parallel plane 54, the subsequent cutting process can be shortened.

Using the intermediate product 50 or 56 thus obtained, as shown in FIG.
Is manufactured. In manufacturing the joint fitting 22, the hollow portion 14 and the hollow portion 18 are not subjected to cutting work, the manufacturing process is significantly shortened, and consumption of consumable tools such as a cutting tool and a drill is eliminated, and the material is Therefore, the manufacturing cost of the fitting 22 is significantly reduced. On the other hand, since the metal flow that flows into the joint metal fitting 22 is hardly cut by cutting, the strength of the joint metal fitting 22 is improved as compared with the conventional product.

In the method for manufacturing the intermediate product of the joint fitting described above, the cylindrical shaft portion 34 of the bottomed hollow material 36 shown in FIG. 2 (c) is drawn, and the intermediate product 50 shown in FIG. 2 (d) is drawn. When manufacturing the above, if the cross-sectional reduction rate of the cylindrical shaft portion 34 of the bottomed hollow material 36 is 50% or less, it is possible to perform drawing with the cylindrical shaft portion 34 partially open.

That is, as shown in the mold structure 58 in FIG. 3, the movable side is a hemispherical mold 60 having a diameter equal to that of the hemispherical surface 32.
And a molding punch 62 having On the other hand, on the fixed side, a semi-spherical mold 64 formed with a spherical diameter equal to the spherical diameter of the head 16 of the joint fitting 22 which is a finished product or the hemispherical surface 46 of the intermediate product 50, and the intermediate product 50. Cylindrical shaft 4
A molding die 68 having a drawing die 66 formed with an inner diameter corresponding to the shaft diameter of 4 and the hole size of the hollow portion 18 of the joint fitting 22 or the cylindrical shaft portion 44 of the intermediate product 50 are determined. The mandrel 70 and the protrusion sleeve 72 required when the length of the cylindrical shaft portion 44 of the intermediate product 50 is determined and the molded intermediate product 50 is extracted from the molding die 68.
A spacer 74 for ensuring a stroke of sliding of the protrusion sleeve 72, a back die 75 for holding the mandrel 70, and a pressure acting on the mandrel 70 and sliding the protrusion sleeve 72. A back die 77 that holds a knockout pin 76 for moving is configured. Then, the knockout pin 76 is operated via the pin 78 at a set timing by the protrusion mechanism provided in the apparatus main body. Here, the tip of the mandrel 70 arranged through the drawing die 66 is sufficiently projected from the hemispherical die 64.

Therefore, as shown in FIG. 3, in the molding operation using the mold structure 58, the cylindrical shaft portion 34 of the bottomed hollow material 36 is arranged on the hemispherical mold 64 side, and the bottomed hollow material is formed. 36 is pressed by the forming punch 62, and the cylindrical shaft portion 34
Is plastically deformed into a hemispherical shape (46) by the hemispherical mold 64, and is squeezed into a space formed between the drawing mold 66 and the mandrel 70 to form an intermediate product 50 as shown in FIG. . In such drawing, the cross section of the cylindrical shaft portion 34 of the hollow material 36 with a bottom has a cylindrical shaft portion 44 of the intermediate product 50.
When the cross-section reduction rate of the cross-section of the sphere is 50% or less, the above-mentioned drawing process can be performed, and the molded sphere 1
A spherical cavity 14 is formed inside 0, and
The hollow portion 18 communicating with the hollow portion 14 is simultaneously press-formed. Here, the spherical body 10 is molded by the hemispherical mold 60 of the molding punch 62 and the hemispherical mold 64 of the molding die 68.

Intermediate product 5 formed by forging as described above
As shown in FIG. 5, the knockout pin 76 is pushed out by the pin 78 of the push-out mechanism as the molding punch 62 moves away from the fixed side mold, and as a result, the push-out sleeve 72 slides. The result is that they are pushed out. The intermediate product 50 taken out is, if necessary, subjected to a trimming process in the next step so that a part of the spherical body 10 is a parallel flat surface 54 in which the axial direction of the cylindrical shaft portion 44 is parallel.
Then, two surfaces are cut to obtain an intermediate product 56.

Thereafter, in the obtained intermediate product 50, a part of the sphere 10 is cut on two sides by cutting or the like, and an intermediate product 56 which is cut on two sides by trimming is machined on the two-sided cut. To form flat and parallel surfaces. Next, after the cylindrical shaft portion 44 and the like are subjected to cutting work to form the joint metal fitting 22 as shown in FIG. 1, heat treatment is performed if necessary, and further plating and other surface treatments are performed to obtain a finished product. That is, the joint metal fitting 22 is manufactured.

The embodiment of the mold structure used in the method of manufacturing the intermediate product of the fitting according to the present invention has been described above.
The present invention is not limited to the above embodiment. In particular, the above-mentioned mold structure has a sufficiently low cross-sectional reduction rate, there is no risk of buckling, or the sphere diameter of the head of an intermediate product is the sphere of a bottomed hollow material that is a preform thereof. When it is necessary to set the diameter larger than the diameter, when the hollow material with a bottom, which is such a preform, is to be inserted into the molding die, it may not be possible to insert it vertically on the center axis of the mold. At this time, if the molding is performed by the above-mentioned method, the sphericity of the sphere is deteriorated, the desired product accuracy cannot be obtained, and the outer diameter of the sphere is along the parting line between the molding punch 62 and the molding die 68. Burrs may be generated in the part and the inside of the cavity may be deformed.

In order to prevent such a problem, it is preferable to add the following one step. That is, as shown in FIG. 6, at least the tip of the cylindrical shaft portion 34 of the bottomed hollow material 36 shown in FIG. 2 (c) is formed in a molding die 80 formed with a minimum inner diameter that can be smoothly inserted. A part of the cylindrical shaft portion 34 is inserted, the hollow material 36 with a bottom is further pushed forward by the punch 82 and drawn, and the cylindrical shaft portion 44 of the intermediate product 50 is drawn and formed as shown in FIG. A preform 84 of is obtained. As shown in FIG. 8, the shape of the sphere 86 of the preform 84 obtained by this forging is such that the shape of the sphere of the head is an ellipse on the vertical axis. The cylindrical shaft portion 44 of the preform 84 of this intermediate product is then inserted into the molding die 68 of the mold structure 58 shown in FIG. 3, and the intermediate product 50 having the substantially spherical sphere 10 is formed by forging. obtain. This forming step is a processing method of obtaining a target shape by drawing and then upsetting.

As described above, when molding the intermediate product 50 shown in FIG. 2D from the hollow material 36 with a bottom shown in FIG. First, the hemispherical surface 32 of the bottomed hollow material 36 shown in Fig. 2 (c).
The outer diameter and the inner diameter of the sphere etc. are molded to be smaller than the outer diameter and the inner diameter of the sphere 10 of the intermediate product 50 shown in FIG. 8 (d) to obtain the preform 84 shown in FIG. It is preferable to upset the spherical sphere 10. That is, it is preferable to perform molding by using both drawing and upsetting.

Although the embodiments of the present invention have been described in detail above, it goes without saying that the present invention is not limited to the above-mentioned embodiments.

For example, as shown in FIG. 9 (a), the shape of the mandrel may be such that a draw-molded portion 88 is formed at the tip and a relief 90 is formed at the other shafts. As shown in FIG. 2B, the mandrel shaft portion 92 may be formed to have a predetermined size. Furthermore,
As shown in (c) of the figure, a hole 9 is formed in the center of the mandrel.
4 is provided, and the sphere 10 is formed when the intermediate product 50 or the like is molded.
The air or oil that is compressed and confined in the hollow portion 14 inside may be released to the outside through the hole 94.

The length of the protrusion sleeve 72 may be configured so that the length of the cylindrical shaft portion 44 of the intermediate product 50 can be adjusted, but the length of the protrusion sleeve 72 is the intermediate product. It is sufficient if 50 protrusions are possible. Further, the columnar material 24 shown in FIG. 2 (a) can be directly pressure-formed into the shape of the hollow material with a bottom 36 shown in FIG. 2 (c) in view of the material and the forging method. Is.

Further, although the above-mentioned embodiments have been described mainly for the purpose of cold forging, it goes without saying that warm forging or hot forging may be used. Further, although alloy steel is mainly used as the material, other materials such as aluminum alloy may be used without any particular limitation. Other,
The present invention can be carried out in a mode in which various improvements, modifications and variations are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

Example 1 First, as for the shape of the bottomed hollow material 36 shown in FIG. 2 (c), the spherical diameter of the hemispherical surface 32 and the outer diameter of the cylindrical shaft portion 34 are 21.8 mm,
The inner diameter of the hemispherical surface 40 was 15.8 mm, the inner diameter of the hollow portion 42 was 18 mm, the length of the hollow portion 42 was 29 mm, and the total length was 53 mm. Using this bottomed hollow material 36, an intermediate product 50 shown in FIG. 2 (d) was molded by a mold structure 58 shown in FIGS. As for the dimensions of the obtained intermediate product 50, the outer diameter of the spherical body 10 is 22 mm, the inner diameter of the hollow portion 14 is 16 mm, the outer diameter of the cylindrical shaft portion 44 is 11 mm, the inner diameter of the hollow portion 18 is 6 mm, and the total length is 60 mm. Met.

When the manufactured intermediate product 50 was inspected, no burr was generated on the parting line between the forming punch 62 and the forming die 68, and the meat portion between the spherical body 10 and the spherical cavity 14 was formed. It was possible to smoothly mold hollow spheres and hollow cylinders having a wall thickness of about 3 mm without buckling.

Embodiment 2 Similar to Embodiment 1, the shape of the hollow material 36 with a bottom shown in FIG. 2 (c) is that the spherical diameter of the hemispherical surface 32 and the outer diameter of the cylindrical shaft portion 22 are 22 mm and the hemispherical surface 40. Inner diameter of 14mm, hollow part 42
Has an inner diameter of 18 mm and the length of the hollow part 42 is 18 m.
m, the total length was 53 mm. Using this bottomed hollow material 36, an intermediate product 50 shown in FIG. 2 (d) was similarly molded by the mold structure 58 shown in FIGS. This processing method is simultaneous processing of drawing and upsetting. The size of the obtained intermediate product 50 is such that the outer diameter of the sphere 10 is 24 mm,
The inner diameter of the hollow portion 14 is 16 mm, the outer diameter of the cylindrical shaft portion 44 is 11 mm, the inner diameter of the hollow portion 18 is 6 mm, and the total length is 61.
It was 3 mm.

Intermediate product 50 produced as in Example 1
As a result of inspection, there was no burr on the parting line between the forming punch 62 and the forming die 68.
Further, the wall portion between the spherical body 10 and the spherical cavity portion 14 did not buckle, and the hollow spherical body and the hollow cylindrical body having a wall thickness of about 4 mm could be smoothly molded.

[0043]

In the joint fitting according to the present invention, at least the hollow portion of the head portion and the hollow portion of the cylindrical shaft portion are integrally formed by forging, so that it is necessary to machine these hollow portions and hollow portions. In addition, the time and cost for manufacturing the joint fitting can be significantly reduced, and the consumption cost of consumable tools such as a bite and a drill is not consumed, so that the manufacturing cost can be further reduced. On the other hand, since the obtained joint metal fitting is not subjected to the cutting work inside, it is constituted by the fiber structure in which the metal flow is continuous as the whole product, and the strength is significantly improved.

Further, in the method for manufacturing an intermediate product of the fitting according to the present invention, first, the inner and outer hemispheres of the head of the fitting, that is, the head of the intermediate product and its wall thickness are press-formed, and then the intermediate cylinder is formed. Since the shaft part and the inner and outer hemispheres of the head part that follows it are drawn and forged, the manufacturing process is almost the same as the manufacturing process required to manufacture a conventional solid intermediate product. be able to. Moreover, according to such a manufacturing method, the metal flow is not cut, and the joint fitting having high strength can be manufactured.

Further, in this manufacturing method, by using the mandrel, the inner diameter of the hollow portion of the cylindrical shaft portion can be formed with high accuracy. Further, in such a manufacturing method, the spherical head of the intermediate product is cut on two sides by trimming, whereby the subsequent cutting process can be significantly shortened.

[Brief description of drawings]

1A and 1B are views showing an example of a joint fitting to which the present invention is applied, FIG. 1A is a front sectional view, and FIG. 1B is a plan sectional view.

2 (a) to 2 (e) are views showing a representative example of a method for manufacturing an intermediate product of a fitting according to the present invention, and (a) and (b)
Is a front view, and (c) to (e) are front sectional views.

FIG. 3 is a cross-sectional view showing a mold structure used in a method for manufacturing an intermediate product of a fitting according to the present invention and one processing step.

FIG. 4 is a cross-sectional view showing a next processing step using the mold structure shown in FIG.

5 is a cross-sectional view showing a further processing step by the mold structure shown in FIG.

FIG. 6 is a cross-sectional view showing another mold structure used in the method for manufacturing the intermediate product of the fitting according to the present invention and one processing step.

FIG. 7 is a cross-sectional view showing a next processing step using the mold structure shown in FIG.

FIG. 8 is a front sectional view showing a preformed product of an intermediate product of the fitting according to the present invention.

9 (a) to 9 (c) are each an enlarged view of the essential parts showing another embodiment of the mandrel used in the method for manufacturing the intermediate product of the fitting according to the present invention.

10 (a) and 10 (b) are front sectional views showing an example of a joint fitting.

11A and 11B are views showing a conventional intermediate product for manufacturing a fitting, in which FIG. 11A is a front view and FIG. 11B is a fragmentary front view.

12 (a) to 12 (f) are views showing a typical example of a conventional method for manufacturing an intermediate product of a fitting, wherein FIGS. 12 (a) to 12 (d) are front views, (e) and (f). ) Is a front sectional view.

[Explanation of symbols]

 10; sphere 12, 54; parallel plane 14; cavity portion 16; head portion 18, 42; hollow portion 20, 44; cylindrical shaft portion 22; joint metal fitting 24; cylindrical material 26; hemispherical shape 28; cylindrical shape 32, 40, 46, 48; hemispherical surface 34; cylindrical shape 36; hollow material with a bottom 38; material 50, 56; intermediate product 52; taper 58; mold structure 62; forming punch 64; hemispherical surface mold 66; drawing mold 68 , 80; molding die 70; mandrel 84; preform

Claims (3)

[Claims] 1. A cylindrical shaft provided with a head part having a hollow part formed therein and having a hollow part formed by cutting a sphere into two parallel planes, and a hollow part integrally extending from the head part and communicating with the hollow part. In the joint metal fitting, the joint metal fitting is characterized in that at least the hollow portion of the head portion and the hollow portion of the cylindrical shaft portion are integrally formed by forging. 2. A method for manufacturing an intermediate product for manufacturing a fitting according to claim 1, wherein one end side of a cylindrical material having a predetermined size has the same or slightly smaller spherical diameter as the spherical diameter of the intermediate product. While forging into a substantially hemispherical surface having the other side, and at the same time or after forging the other end side of the cylindrical material into an outer diameter approximately the same as the spherical diameter of the hemispherical surface, rearward from the other end side. By extrusion molding, the inside of one end side of the hemispherical surface is made into a hemispherical surface having a spherical diameter substantially the same as or slightly smaller than the inner diameter of the cavity of the head of the intermediate product, and the wall thickness of the head of the intermediate product. A preforming step of forming by forging into approximately the same wall thickness, on the other hand, the inside of the other end side of which is formed a cylinder having an inner diameter substantially equal to or larger than the inner diameter of the internal hemispherical surface, and the preformed material While forming the outer diameter of the cylindrical part to the outer diameter of the cylindrical shaft part of the intermediate product, intermediate the hemisphere side of the material Method for producing an intermediate product of joint fittings, characterized in that it comprises a forming step of forming the sphere of the head. 3. In the forming step, a mandrel having an outer diameter substantially the same as the inner diameter of the hollow portion of the cylindrical shaft portion of the fitting is disposed inside the cylinder of the material while A hemispherical draw forming portion having a spherical diameter equal to that of the head portion and a draw forming portion having an inner diameter equal to the outer diameter of the cylindrical shaft portion of the intermediate product form the shaft portion and the head portion into a spherical shape. The method for manufacturing an intermediate product of a fitting according to claim 2, characterized in that.