JPS6231202B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to the manufacture of a shaft having a spherical portion rotatably supported by a mounting portion, which is suitably used as a component for an automobile, such as a change lever or a rear view mirror. It is about the method.

Conventional technology Conventionally, shafts with this type of spherical portion were formed by forging, etc. with a machining allowance at the location corresponding to the spherical portion, and then the spherical portion was processed by machining.
There was a problem of high cost due to large material loss and many processing steps.

In order to reduce the above-mentioned material loss and processing man-hours, in Japanese Patent Publication No. 53-33309, a connecting piece with a through hole that fits the outer circumference of the lever and a slightly thin cylindrical tongue piece are installed in appropriate places on the lever part. A manufacturing method for providing a spherical part in a lever part by fitting and inserting a spherical part material having a spherical part into the through hole, coupling a connecting piece to the lever part, and then forming a cylindrical tongue piece into a spherical surface. is proposed.

However, in the above method, the ball part material of the tube material has a through hole that is adapted to the outer periphery of the lever part,
It is necessary to provide a connecting piece that is connected to the lever part by welding, etc., and forging or sheet metal processing is required to manufacture the ball part material, which increases the number of man-hours for processing the ball part material and increases costs. Along with becoming
This requires a step of joining the connecting piece of the ball member to the lever part by welding or the like, and is not very effective in reducing the number of processing steps.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems of the prior art, and to provide a method for manufacturing a shaft having a spherical portion with a small number of processing steps and at a low cost. The invention involves inserting a metal base shaft with a circular cross section into a cylindrical metal tube, placing the tubes at appropriate positions on the base shaft on a concentric axis, and forming a single spherical surface by placing the tubes on both sides of the tube, respectively. Using a two-part press mold that moves and presses each other in the axial direction to form a shape, the outer shape of both sides of the pipe material is forged into a spherical shape, and at the same time, in the final stage of the forging process, the peripheral edges of the openings on both sides of the pipe material are , has created a method for manufacturing a shaft having a spherical portion, which is characterized in that the end is fixed to the outer circumferential surface of the base shaft by compression contraction of the end.

Further, the second invention provides a clamp member for supporting a central portion of the outer circumferential surface of a pipe material in which a metal base shaft having a circular cross section is inserted into a cylindrical metal pipe material and placed at an appropriate position on the base shaft. The outer shape of both sides of the tube is fixed using a two-piece press mold that is fixed on a base axis and a concentric axis, and is placed on both sides of the tube and presses movably in the axial direction so that they form one spherical surface. At the same time, the clamp member is released and removed just before the end of the forging process, and the ends of the peripheral edges of the openings on both sides of the tube are fixed to the outer circumferential surface of the base shaft by compression contraction of the ends. The present invention provides a method for manufacturing a shaft having a spherical portion, which is characterized by the following.

Embodiments Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

In Fig. 1, reference numeral 1 denotes a shaft having a spherical part that is rotatably supported on the mounting part of the automobile as a component of the on-vehicle equipment of the automobile, and the shaft is a hollow, linear metal base shaft 2 with a circular cross section. , and the spherical portion is constituted by a metal spherical shell 3 that is hollow inside and has a pair of through holes 4, 4 on both sides through which the base shaft passes. The spherical shell portion is made to correspond to the base shaft by inserting a cylindrical tube into the appropriate position, and then the tube is temporarily clamped with a clamp member so as to be arranged concentrically with the base shaft.
Next, the tube is subjected to spherical forging with press dies placed on both sides of the opening of the tube, and during the process of spherical forging, the holding means 9 is released, and the contraction force at both ends of the opening of the tube causes the tube to be centered around the base axis. Fix it.
The spherical shell 3 has a through hole 4 provided at its center inserted into the base shaft, and the axial openings on both sides of the spherical shell 3 form vertical surfaces 5, 5, and the terminals 6 of the vertical surfaces 5, 5. , 6 are narrower than the outer diameter of the base shaft 2, recesses 7, 7 are formed on the outer periphery of the base shaft 2 corresponding to the terminals 6, 6, and the terminals 6, 6 are fitted and fixed in the recesses 7, 7, Therefore, the shaft has a spherical portion.

2 to 5 show the manufacturing process of the shaft having the spherical portion shown in FIG. 1 above. First, as shown in FIG. 2, the base shaft 2 is placed at the center of the cylindrical guide 8, and the portion of the base shaft 2 where the ball is provided is located at a position opposite to the holding means 9 attached to the guide 8 so as to be retractable. let Next, as shown in the figure, make a through hole 4 in the center.
A cylindrical tube 10 having a cylindrical shape is inserted into the base shaft 2, and a holding means 9 serving as a clamp member is made to protrude from the guide 8 to hold the outer periphery of the tube 10 and temporarily clamp the base shaft 2 and the tube 10 so that they are concentric. are doing.
At this time, there is a uniform gap 11 in the axial direction between the inner circumferential surface of the tube material 10 and the outer circumferential surface of the base shaft 2. As mentioned above, a cylindrical tube 1 is attached to the outer periphery of the base shaft 2 at a predetermined position.
0, the press molds 12A and 12B, which are divided into two on both sides of the tube 10 in the axial direction, are slidably fitted into the guide 8. The pair of press molds 12A,
12B has mold cavities 13A and 13B in which spherical parts are formed on opposing surfaces on the side of the tube material 10, and has base shaft insertion holes 14A and 14B in the axial direction in the center, and the insertion holes 4A and 14B are connected to the base shaft 2. It is slidably fitted on the outside. The mold holes 13A and 13B form flat surfaces 15A and 15B perpendicular to the small diameter portion that contact the base shaft insertion holes 14A and 14B, and are slightly cut outward in the large diameter portion (parting portion) to prevent burr generation. The inclined surfaces 16A and 16B are formed.
The lengths l ₁ and l ₂ of the mold cavities 13A and 13B are set such that the length L of the tube material 10 is larger than the sum of the lengths l 1 and l 2 .

(l ₁ +l ₂ <L) Press mold 12 with the spherical part divided into two as described above
After arranging the press molds 12A and 12B on both sides of the opening side of the tube material 10, as shown in FIG.
are pressurized and moved within the guide 8 in the direction of bringing them close to each other, and the large diameter portions of the opposing inner sides of both press molds 12A and 12B are fitted onto both sides of the tube material 10. In this state, the tube material 10 has press molds 12A and 12 on both sides.
Since the tube material 10 is held at B, next, the holding means 9 temporarily clamping the tube material 10 is inserted into the guide 8, and the clamping by the holding means 9 is released. When the press molds 12A and 12B are moved closer together, the tube material 10
A spherical shell 3 is formed along the mold holes 13A and 13B into a spherical shape with the maximum diameter at the axial center of the through hole 4 and smaller diameters at both open sides. Press mold 12
In the final step shown in FIG. 5 in which the inner end surfaces of tubes A and 12B come into contact, both ends of the tube material 10 are pressed into press molds 12A and 12B.
Vertical surfaces 5, 5 are formed by the flat surfaces 15A, 15B of 12B, and the ends 6, 6 (both opening ends of the pipe material 10) of the vertical surfaces 5, 5 dent the outer periphery of the base shaft 2 by contraction force. It is fixed in the biting state. Furthermore, since the contact surfaces of the press dies 12A and 12B have inclined surfaces 16A and 16B for preventing burr generation, burrs do not occur on the maximum outer diameter portion 3a (parting portion) of the spherical shell 3. In addition, press mold 12A,
If the slanted surface for preventing burr generation is not provided on 12B, burr cutting may be performed in the next step after the spherical shell 3 is fixed onto the base shaft 2 using a press mold. It may also be formed into a vertical surface using a press mold, and any burrs generated may be contained within the ball ring to eliminate the need for burr cutting.

Further, in the above embodiment, flat surfaces are formed on both sides of the opening of the spherical shell 3, but if the vertical surfaces 5, 5 are not formed, the portions close to both sides of the opening will become a little thinner, and Wrinkles will occur at the end of the opening and the clamping force will become somewhat unstable, but if the vertical surfaces 5, 5 are provided, the thin parts near the vertical surfaces will tend to actively follow the mold surface, Improves spherical accuracy and prevents wrinkles on the terminal.
The force becomes stable. However, it is not always necessary to form both sides of the opening of the spherical shell body 3' flat, and depending on the usage conditions of the shaft having a spherical part, both ends of the opening of the spherical shell body 3' may be formed along a circular pattern as shown in FIG. Ivy-shaped,
The terminal 6' may be fixed to the base shaft 2. In addition, in the embodiment shown in FIGS. 6 and 1, the entire end of the spherical shell is fitted into the recess 7 of the base shaft, but the length of the spherical shell (the axial length of the tube material ) is short, a part of the end 6'' of the spherical shell 3'' may be fixed to the base shaft 2, as shown in FIG. In each of the above embodiments, the base shaft is hollow.
As shown in the figure, when the base shaft is a round bar, it is difficult to fit the spherical shell into the base shaft and fix the base shaft 2'.
If the surface 2'a is roughened by serration processing or the like, the biting force will be improved.

In the manufacturing shown in FIGS. 2 to 5 described above, the cylindrical tube material 10 is temporarily clamped with the guide 9, but the guide 9 is eliminated and the press mold 12
A, 12B may support both sides of the opening of the tube material 10 as shown in FIG.
Either one of 2B may be fixed and only the other may be moved.

Base shaft 1 having a spherical part manufactured by the above process
As shown in FIG.
The spherical shell body 3 is rotatably fitted into the support hole 20a to rotatably support the back mirror.

As is clear from the above description, according to the present invention, a cylindrical tube material is placed in a suitable position in a linear hollow space, and the tube material is subjected to spherical forging with a press die having a spherical portion divided into two parts. Since both ends of the opening are fixed to the base shaft to form a shaft with a spherical part, the number of processing steps is reduced compared to the conventional method, and the shape of the tube material that forms the spherical part is cylindrical and simple, reducing costs. It can be lowered to a large extent. In addition, in particular, if the tube material is temporarily clamped with a holding means before being forged with a press die, misalignment of the spherical shell with respect to the base axis can be minimized, and a shaft with a highly accurate spherical part can be manufactured. can.

According to the embodiment of the present invention, a recess is formed in the base shaft, and the terminals of the vertical surfaces at both ends of the spherical shell are fixed to the recess, so that the spherical shell is firmly fixed in the axial direction of the base shaft. The fixing force is strong because it can be fixed in the direction of rotation and is fixed in the rotating direction. In addition, since vertical surfaces are formed at both ends of the opening of the spherical shell, the accuracy of the spherical shape is improved, wrinkles can be prevented from occurring at the end, and the adhesive force is stabilized, among other effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a shaft having a spherical portion manufactured by the method of the present invention, FIGS. 2, 3, 4 and 5 are sectional views sequentially showing the manufacturing process of the shaft.
The figure is a sectional view of a shaft showing another embodiment of the invention, FIGS. 7 and 8 are sectional views of essential parts showing other embodiments of the invention, and FIG. 9 is a shaft sectional view of a shaft according to the invention. It is a sectional view showing an example of use. 1...axis, 2...basic axis, 3...spherical shell, 4...
Through hole, 5... Vertical surface, 6... Terminal, 7... Recess, 8... Guide, 9... Holding means, 10... Tube material, 12A, 12B... Press mold.

Claims (1)

[Scope of Claims] 1. A metal base shaft with a circular cross section is inserted into a cylindrical metal tube, and the tubes are arranged on a concentric axis at appropriate positions on the base shaft, and the tubes are arranged on both sides of the tube, respectively. Using a two-part press mold that moves and presses each other in the axial direction so as to form one spherical surface, the outer shape of both sides of the pipe material is pressed into a spherical shape, and at the same time, in the final stage of the forging process, openings on both sides of the pipe material are formed. A method for manufacturing a shaft having a spherical portion, characterized in that the end of the peripheral edge of the end is fixed to the outer circumferential surface of the base shaft by pressure contraction of the end. 2 A metal base shaft with a circular cross section is inserted into a cylindrical metal pipe material and placed at an appropriate position on the base shaft,
Clamp members that support the center portion of the outer peripheral surface of the tube are used to fix the tube on a concentric axis with the base axis, and are arranged on both sides of the tube to be movable in the axial direction so as to form one spherical surface. The outer shape of both sides of the pipe material is pressed into a spherical shape using a two-part press die, and at the same time, just before the end of the forging process, the clamp member is released and removed, and the ends of the peripheral edges of the openings on both sides of the pipe material are shaped into a spherical shape. A method for manufacturing a shaft having a spherical portion, characterized in that the shaft is fixed to the outer peripheral surface of the base shaft by pressure contraction.