JPH033093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method of manufacturing a change lever used as a change lever for, for example, automobiles, trucks, agricultural machinery, and the like.

(B) Prior Art Conventionally, as the above-mentioned change lever, there is a gear shift lever having a structure as shown in FIG. 10, for example.

That is, a synthetic resin spherical body 102 is fitted onto the outer periphery of a relatively short straight base tube 101,
This spherical body 102 is attached to a lever retainer (not shown).
At the same time, a solid lever body 103 is integrally connected to the upper part of the base tube 101 by welding means, and a screw 105 for attaching the change knob 104 is screwed to the upper end of this lever body 103. This change lever is constructed so that a pipe pivot 106 is integrally connected to the lower end of the above-mentioned base pipe 101 by welding means, and a change rod 107 is connected to this pipe pivot 106.

However, the conventional change lever described above has the following problems.

In other words, since the lever body 103 is in the shape of a solid round bar, vibrations from the engine and the transmission section are directly transmitted to the change lever, causing the lever body 103 to vibrate minutely.

Also, the main part of the change lever is the base pipe 101.
Since the lever body 103 is formed of a total of three parts, the spherical body 102 and the lever body 103, there are many parts, and there is a problem in that a welding process is required to connect the base pipe 101 and the lever body 103. The dot was hot.

Furthermore, since there are welded parts due to the above-mentioned welding process, there is a problem that the mechanical strength of these welded parts tends to deteriorate.

Furthermore, due to the large number of parts mentioned above, there was a problem in that the number of assembly steps and management steps were large.

Moreover, since the lever main body 103 is in the shape of a solid round bar, it has a certain weight, which poses a problem in that weight reduction is hindered.

(c) Purpose of the Invention The present invention provides a method for manufacturing a lightweight change lever with few welding and assembly steps by drawing a hollow change lever from a plastic metal pipe using a cold forging method. The purpose of this invention is to provide a method for manufacturing chain that can be used.

(D) Structure of the Invention The present invention includes a first step of press-fitting a punch into one end of a plastic metal pipe of a predetermined length to form an expanded tube portion in a portion corresponding to the spherical portion of the lever to be processed; A first mold consisting of a pair of a lower mold and an upper mold placed opposite each other at the center is divided into two shapes: an intermediate spherical shape that approximates the spherical part of the lever to be processed, and an intermediate connecting shape that approximates the connecting part. Then, a second step of drawing the approximate intermediate spherical part and the approximate intermediate connecting part by pressing these two molds, and a pair of lower mold and upper mold that are opposed to each other at approximately the center of the approximate intermediate spherical part. In a second mold, a spherical surface corresponding to the spherical part of the lever to be processed and a connecting part corresponding to the connecting part are formed separately, and the spherical part and the connecting part are drawn by pressing these two molds. A method for manufacturing a change lever is characterized in that the method includes a third step of:

(E) Effects of the Invention According to this invention, one end of a plastic metal pipe is expanded to form an expanded section at one end of the pipe, and then the expanded section is shaped into an intermediate spherical shape that approximates the final shape and a final shape. After drawing into an approximate intermediate connection shape, the intermediate spherical part and intermediate connection part are cold-forged into a sphere and connection part corresponding to the final shape, making it possible to easily create a hollow change lever from a plastic metal pipe. As a result, it is possible to manufacture
This has the effect of making it possible to obtain a change lever that requires fewer welding and assembly steps, is lightweight, and has sufficient mechanical strength as a whole.

In addition, since the main body of the tubular lever, the ball part, and the connecting part are manufactured as one unit, the number of parts can be reduced, and since there are no welded parts on the main part of the lever, the mechanical strength can be increased. be.

Furthermore, since a hollow change lever can be obtained by the above-described method, vibrations from the engine and the transmission part can be absorbed by the above-mentioned hollow part, especially the hollow part with a large volume inside the bulb part,
This has the effect of attenuating minute vibrations of the change lever, thereby reducing vibrations of the change lever.

(F) Embodiment of the Invention An embodiment of the invention will be described in detail below based on the drawings.

The drawing shows a method of manufacturing a change lever, and the first
In the figure, a change lever 1 made of a plastic metal pipe has a ball part 5 at the lower part of a tubular lever main body 4 in which an upper pipe part 3 is bent at a predetermined angle θ, for example, 15 to 20 degrees with respect to a base part 2. 5. A short tubular connecting part 6 with a wall thicker than other parts at the bottom (see Fig. 9 for details)
Furthermore, a tapered portion 7 is provided at the lower end of this thick connecting portion 6.
They are each integrally formed using a cold forging method using press working.

Further, a short pipe pivot 8 for connecting the ends of the change rod is fixed to the above-mentioned taper portion 7 by welding means.

Furthermore, the above-mentioned tubular lever main body 4 is formed into a tapered shape with a large diameter at the lower part and a small diameter at the upper part, and the upper end of the tubular lever main body 4 has a threaded portion 9.
is screwed on.

The above-mentioned change lever 1 is put into use by having the ball portion 5 pivoted on a lever retainer, connecting the pipe pivot 8 at the lower end to one end of the change rod, and further attaching the change knob to the threaded portion 9 at the upper end.

Next, a method for manufacturing the above-mentioned change lever 1 will be described.

First, as shown in FIG. 2, a No. 1 die 11 having a shaped surface 10 for first-stage tube expansion is provided, and in a bottomed cylindrical die hole 12 of this No. 1 die 11,
Insert the plastic metal pipe 13.

The pipe 13 mentioned above has a predetermined length.

Then, as shown in FIGS. 2 and 3, a No. 1 punch 14 is press-fitted into the upper end of the pipe 13 to form a first expanded tube portion 15 at the upper end of the pipe 13.

After the first stage expanded tube portion 15 is formed, a stepped portion 16 is formed at the boundary between the pipe 13 and the first expanded tube portion 15 .

Further, the formation site of the first stage expanded tube portion 15 is as follows:
This corresponds to the position of the ball portion 5 in the change lever 1 as a completed product shown in FIG.

Note that the above-mentioned No. 1 die 11 is provided with a knockout pin as necessary.

Next, as shown in FIG. 4, a shaped surface 17 for second-stage tube expansion, which has a larger hole diameter than the shaped surface 10 for first-stage tube expansion, is placed in the upper region of the region corresponding to the step portion 16 described above.
A second die 18 having a diameter is provided, and the above-mentioned pipe 13 is inserted into the bottomed cylindrical die hole 19 of the second die 18.

Then, as shown in FIGS. 4 and 5, the first punch 14 is
A No. 2 punch 20 having a larger diameter than the outer diameter of the pipe 13 is press-fitted to form a second stage expanded tube part 21 having a larger diameter than the first stage expanded tube part 15 at the upper end of the pipe 13. (First step) Next, as shown in FIG.
A first mold 24 is provided, which is made up of a pair of a lower mold 22 and an upper mold 23 that are opposed to each other at approximately the center of the mold.

The lower mold 22 and the upper mold 23 have intermediate spherical shaped surfaces 25, 2 which approximate the outer shape of the spherical part 5 in FIG.
6 is divided into halves, and the upper mold 23 includes the first
An intermediate connection-shaped surface 27 that approximates the outer shape of the thick-walled connection portion 6 shown in the figure is formed to be continuous with the above-mentioned intermediate spherical shape surface 26.

Hole 28 of the above-mentioned lower die 22 formed in this way
Insert the aforementioned pipe 13 into the lower mold 22 on the fixed side.
Press the upper mold 23 on the movable side against the fifth
The second stage expanded pipe section 21 shown in the figure is plastically deformed, and an approximate intermediate spherical section 29 and an approximate intermediate connecting section 30 as shown in FIG. 6 are drawn. (Second step) Next, as shown in FIG.
A second mold 33 consisting of a pair of a lower mold 31 and an upper mold 32 which are disposed opposite each other approximately in the center of the mold 9 is provided.

The above-mentioned lower mold 31 and upper mold 32 are divided into halves with spherical shaped surfaces 34 and 35 corresponding to the final shape corresponding to the outer shape of the spherical part 5 in FIG.
1, a connecting shaped surface 36 corresponding to the outer shape of the thick connecting portion 6 shown in FIG. 1 is formed so as to be continuous with the above-mentioned spherical shaped surface 35.

Hole 37 of the above-mentioned lower mold 31 formed in this way
Insert the aforementioned pipe 13 into the lower die 31 on the fixed side.
Press the upper mold 32 on the movable side against the sixth
Approximate intermediate sphere portion 29 and approximate intermediate connecting portion 30 shown in the figure
is plastically deformed, and the spherical portion 5 and connecting portion 6 are drawn as shown in FIG. (Third Step) Next, as shown in FIG.
A mold 40 is provided.

The above-mentioned lower mold 38 and upper mold 39 have spherical shaped surfaces 41 and 42 that correspond to the outer shape of the spherical part 5 divided into halves, and the upper mold 39 has a final mold that corresponds to the outer shape of the connecting part 6. A connected shape surface 43 corresponding to the shape, and a first
A tapered portion shaped surface 44 corresponding to the outer shape of the tapered portion 7 shown in the figure is formed to be continuous with the above-mentioned spherical shaped surface 42.

Then, the upper mold 39 on the movable side is pressed against the lower mold 38 on the fixed side, and the end surface of the connecting part 6 is plastically deformed in an inclined shape in the axial direction, as shown in FIGS. 8 and 9. Thus, the tapered portion 7 is formed on the end surface of the above-mentioned connecting portion 6, and at the same time, the thickness of the connecting portion 6 is increased. (Fourth step) That is, in FIG. 9, when the wall thickness of the spherical portion 5 is t ₁ and the wall thickness of the thick connecting portion 6 is t ₂ , t ₁ <t ₂
The thickness of the connecting portion 6 is increased so that.

The pipe 13 below the ball portion 5 shown in FIG. 7 is plastically deformed into a predetermined shape as shown in FIGS. 8 and 9 through several drawing steps (not shown).

That is, the lower side of the above-mentioned spherical portion 5 in FIG. 8 is drawn into a tapered portion to form the tubular lever main body 4 having a tapered portion as shown in FIG. 9.

Further, the tip of the tubular lever main body 4 is threaded to form the threaded portion 9 shown in FIG. The change lever 1 shown is formed.

In Fig. 1, a pipe pivot 8 is welded to the lower end of the tapered part 7, but since the above-mentioned connecting part 6 and tapered part 7 are thickened and the tapered part 7 is formed, welding work is facilitated. By increasing the thickness of only the necessary parts, the weight of the change lever as a whole can be reduced.
This has the effect of sufficiently increasing the strength of the lower part of the ball part 5 to which the most force is applied when connecting it to a change rod or the like.

Incidentally, if the wall thickness of the connecting portion 6 is thin, the base material will melt during welding, making welding difficult.
By the process described above, it is possible to manufacture a change lever that can solve these problems and perform good welding work.

Further, since the thickness of the threaded portion 9 described above can be increased by the same processing means, the threaded portion 9 can be maintained at a predetermined strength after thread cutting.

Moreover, since the hollow change lever 1 is drawn from the plastic metal pipe 13 by the above-described cold forging method, it is possible to significantly reduce the weight compared to the conventional product shown in FIG. This has the effect of reducing welding processes and assembly processes.

Moreover, the tubular lever main body 4 is manufactured by the above-mentioned manufacturing method.
Since the ball part 5 and thick-walled connecting part 6 are integrally formed, the number of parts can be significantly reduced compared to conventional products, which reduces management man-hours, and
This also has the effect of improving the external shape.

Furthermore, since the change lever 1 can be provided in a hollow shape, when it is installed and used in a vehicle or other transmission part, the vibrations from the engine and transmission part can be absorbed by the hollow part, especially the ball part 5 with a large internal volume. This has the effect of reducing minute vibrations of the change lever 1 by absorbing them in the internal space of the engine.

Furthermore, since it is a cold forged product, the surface is smooth and dimensional accuracy is high, and there is no need for finishing or correction processing after processing.

Furthermore, in the first step (see FIGS. 2 to 5) of the above-mentioned embodiment, the case is illustrated in which multiple steps are performed in which the diameter of the punch is sequentially increased. However, depending on the material of the pipe or the size of the bulb 5, a sufficiently satisfactory product can be obtained even with only one tube expansion step.

It goes without saying that knockout pins may be provided on the first die 11, the second die 18, and each of the lower molds 22, 31, and 38, if necessary.

In the correspondence between the structure of this invention and the above-described embodiment, the punch of this invention is the first punch 14 of the embodiment.
and No. 2 punch 20, and similarly below. The tube expansion section is also for the first tube expansion section 15 and the second stage tube expansion section 21. The present invention is not limited to the configuration of the above-described embodiment.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of the change lever, and FIG. 2 is a perspective view of the first pipe expansion lever.
A sectional view showing the pre-stage process, Figure 3 is the first stage of pipe expansion.
4 is a sectional view showing the step of pipe expansion, FIG. 5 is a sectional view showing the second step of pipe expansion, and FIG. 6 is a sectional view of the process of forming an approximate intermediate sphere. FIG. 7 is a cross-sectional view showing the process of forming the spherical part, FIG. 8 is a cross-sectional view showing the process of forming the thick-walled joint, and FIG. 9 is an enlarged cross-section of the lever to be processed after the cold forging process. 10 are explanatory diagrams of a conventional change lever. DESCRIPTION OF SYMBOLS 1... Change lever, 5... Ball part, 6... Connecting part, 13... Plastic metal pipe, 14... No. 1 punch, 15... First stage tube expansion part, 20... No. 2 punch, 21... ...Second stage tube expansion part, 22, 31...Lower mold, 23, 32...Upper mold, 24...First mold, 2
5, 26... Intermediate spherical shaped surface, 27... Intermediate connected shaped surface, 29... Approximate intermediate spherical part, 30... Approximate intermediate connecting part, 33... Second mold, 34, 35...
Spherical shaped surface, 36... connected shaped surface.

Claims (1)

[Claims] 1. A first step of press-fitting a punch into one end of a plastic metal pipe of a predetermined length to form an expanded tube portion at a portion corresponding to the spherical portion of the lever to be processed; A first mold consisting of a pair of a lower mold and an upper mold placed opposite each other is divided into two shapes: an intermediate spherical shape approximating the spherical part of the lever to be processed, and an intermediate connecting shape approximating the connecting part. a second step of drawing the approximate intermediate spherical portion and the approximate intermediate connecting portion by pressing both dies; and a second step consisting of a pair of a lower mold and an upper mold that are opposed to each other approximately in the center of the approximate intermediate spherical portion. A third step is to divide the mold into a spherical shape corresponding to the spherical part of the lever to be processed and a connecting part corresponding to the connecting part, and draw the spherical part and the connecting part by pressing these two molds.
A method for manufacturing a change lever formed by the steps of. 2. The method according to claim 1, further comprising a fourth step of increasing the wall thickness of the connecting portion by pressurizing the end face of the connecting portion in an axially inclined manner following the third step. How to make a change lever.