JP2002210519A - Method for machining recess of head rest stay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple method for machining the sharp recess of head rest stay at a low cost. SOLUTION: A method is presented for machining a recess 2 which is prepared in the stay 32 part of a head rest stay 3 made of a pipe material. A punch 4 is rotated and abutted against the stay part 32 with pressure for preliminary forming of the recess 2, and then, the recess 2 is formed by press working using a press punch 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for machining a recess of a headrest stay attached to an upper end of a seat back of a vehicle.

[0002]

2. Description of the Related Art A plurality of recesses 2 for height adjustment are provided at predetermined intervals on stay portions 32 of a headrest stay 3 so that a head of an occupant can be fitted to a headrest S attached to an upper end of a seat back of an automobile or the like. (FIGS. 9 and 10). In the drawing, reference numeral 2a denotes a recess for preventing the headrest from coming off, reference numeral 2b denotes a locking concave portion, reference numeral 31 denotes an insert portion, and reference numeral 7 denotes a pillow portion. For the headrest stay 3 incorporated in the headrest S, in recent years, a pipe material is often used for weight reduction. However, these recesses 2 have been cut by a milling method, a broach, or the like.
It has been formed by a method such as press working.

[0003]

However, the recess of the headrest stay made of a pipe plays a role of holding the vertical position by adjusting the vertical position, and must naturally satisfy a predetermined strength. Was. When the recess is formed by the above-mentioned cutting, it is necessary to use a thick-walled pipe so that a predetermined strength can be maintained even at the thinnest portion (a in FIG. 11). Even in the case where preliminary concave processing is performed in advance at the concave processing position by milling or broaching, it is necessary to secure a predetermined thickness at the thinnest place (FIG. 11).
B). On the other hand, when the concave portion is cut out and formed by the above-mentioned press working, a large burr is generated due to abrasion of a punch or the like, and polishing is costly (C in FIG. 11). Further, the fractured surface was dirty, and it was difficult to obtain a sharp edge required as a function of the concave portion. In addition, a sharp shape could not be formed due to the characteristics of the pipe by a method of holding the pipe in a mold and simply pushing it in from above with a punch. As a result, FIG.
The dripping as shown in (d) of 1 occurred. There was a problem that the stopper function could not be exerted due to the dripping of the press work, and the headrest came off from the upper end of the seat back.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method of processing a concave portion of a headrest stay which can provide a sharp concave shape simply and at low cost.

[0005]

In order to achieve the above object,
The gist of the invention according to claim 1 is a method of processing a concave portion of a headrest stay provided on a stay portion of a headrest stay made of a pipe material, wherein a preform of the concave portion is formed by pressing the stay portion while rotating a punch. And then forming the recess by press working using a press punch.

The gist of the invention according to claim 2 is a method of processing a concave portion of a headrest stay provided on a stay portion of a headrest stay made of a pipe material, wherein a portion of the stay portion where the concave portion is provided is exposed. The stay is set on the holder, and then the punch is pressed against the stay portion while rotating a disk-shaped punch whose outer peripheral portion is similar to the concave shape in a side view, and then the concave portion is preformed, and then the holder cover is covered with the holder. The method of forming a recess of a headrest stay is characterized in that the recess is formed by press working using a press punch.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for processing a concave portion of a headrest stay according to the present invention will be described in detail. 1 to 8
Is an embodiment of a method of processing a recess of a headrest stay of the present invention, FIG. 1 is an explanatory sectional view of a preforming apparatus in a first step,
FIG. 2 is an enlarged view of the punch of FIG. 1, FIG. 3 is an enlarged view of the periphery of the recess after preforming, FIG. 4 is an explanatory sectional view of a press working device in a second step, and FIG. 5 is a press punch of FIG. Enlarged view of the
FIG. 6 is an enlarged view around the concave portion after the second step, FIG. 7 is an explanatory cross-sectional view in which the periphery of the concave portion after the first step and the second step is superimposed,
FIG. 8 is an explanatory diagram showing the direction of the combined force generated by the centrifugal force and the pressing force when the rotating punch is pressed and lowered to the stay portion.

Prior to the method of processing a concave portion of a headrest stay according to the present invention, a concave portion processing apparatus used for this will first be described. The processing apparatus is provided with a punch 4 in a first step and a press punch 8 in a second step while sharing a lower mold holder 11 for holding and fixing the headrest stay 3.

The holder 11 has two split dies 11a and 11b.
It consists of a lower mold consisting of Cavity 1 with semicircular cross section
The left split mold 11a of FIG.
2 and the stay portion 32 mounted on the left-side split mold is then fixed to the holder 11 by closing the board-shaped right-side split mold 11b as shown in FIG. become. When the right and left split molds 11a and 11b are closed, the holder 11 becomes L-shaped in cross section as shown in the drawing, and the left upper surface forming the arc surface 112 of the right split mold 11b is in close contact with the stay peripheral surface 32a, and the stay portion 32 Is securely held by the holder 11. At this stage, the portion (right side) of the stay portion 32 where the concave portion 2 is provided is exposed,
As described above, even when the headrest stay 3 is set on the holder 11, the preforming of the recess 2 by the punch 4 in the first step can be performed.

The punch 4 is a disk having a shape resembling the concave portion 2 for obtaining the shape of the outer peripheral portion in a side view, and is supported by a rotating shaft 52 of a punch mounting tool 51. The punch mounting tool 51 is usually
It stands by at a position above the portion where the recess 2 of the stay portion 32 set on the holder 11 is provided. Then, while the punch 4 is being rotated clockwise as shown in FIG.
2 is pressed so that the concave portion 2 can be preformed. FIG. 2 shows an enlarged view of the punch 4. FIG. 2A is a front view of the punch 4, and FIG. 2B is a side view of the punch 4. On the outer peripheral portion of the punch 4, a side view shape of the concave portion 2 which is slightly smaller than the final concave shape is ensured while resembling the finally obtained concave shape. As shown in the enlarged view in the circle of FIG.
Is provided with an inclined surface 41 corresponding to the inclined surface 24 of the concave portion 2, and a flat surface 42 and a corner cut surface 43 corresponding to the concave bottom surface 23. By providing the corner cut surface 43 in addition to the rotation of the punch 4, the recess 20 for preforming the recess 2 can be easily formed.

In the second step, the press punch 8 is provided with the recess 20.
This is an apparatus for forming a concave portion 2 having a final shape by applying a press working to the substrate (FIG. 4). The press punch 8 is assembled into a holder cover 12 attached to the holder 11. Holder cover 1 that was waiting upward in the first process
2 is lowered in the second step and attached to the cover, and a press punch passage 121 is formed in the holder cover 12 in the vertical direction. When the holder cover 12 is attached to the holder 11, the passage 12 vertically penetrates the recess 20.
1 is formed, and the press punch 8 is disposed in the passage 121;
By passing through, the sharp concave portion 2 whose vertical surface 21 is perpendicular to the pipe peripheral surface can be processed. In the portion of the press punch 8 that descends and passes through the passage 121, a concave blade portion 8a as shown in FIG. 5 is formed. As shown in the enlarged view in the circle of FIG. 5, the convex shape formed by the upright surface forming portion 81, the bottom surface forming portion 82, and the slope forming portion 83 of the press punch blade 8a is almost equal to the concave shape to be obtained. . In FIG.
Reference numeral 8b indicates a chuck portion.

The method of processing the recess of the headrest stay is as follows.
First, the headrest stay 3 made of a pipe material is set on the holder 11 (FIG. 1). Left and right split type 11a, 11b
Is opened to attach the stay portion 32, and then the stay portion 32 is fixed and set by closing the mold. At this time, the recess 2
The right half of the stay portion 32, which is the portion M where is provided, is exposed.

Next, as a first step, while the rotating shaft 52 is activated and the punch 4 is rotated, the punch mounting tool 5 is rotated.
1 is lowered to the stay portion 32 of the concave portion forming portion M.
The recess 4 is preformed by pressing the stay 4 while rotating the punch 4 extending from the fixture. Punch 4
Is a disk body as described above, and the side view shape of the outer peripheral portion is similar to the concave portion 2. The concave portion 2 is preformed by lowering the disk body of the punch 4 toward the concave portion forming portion M so as to be perpendicular to the longitudinal direction of the stay portion 32.

Since the stay 4 is pressed while the punch 4 rotates, preforming can be performed while suppressing unnecessary deformation of the pipe (stay portion 32). Here, it is more preferable to set the rotating punch 4 to apply a force in a direction of pushing the pipe meat t into the inside O of the pipe. Specifically, in FIG. 1 and FIG. 8, the force G1
Then, the combined force G3 of the force G2 that rotates the punch 4 in the clockwise arrow direction applies a force in the direction of pushing the pipe meat t into the pipe O. Punch 4
When the centrifugal force G21 related to the force G1 for lowering the pressure and the clockwise rotation force G2 of the punch 4 is applied, the resultant force G3 becomes a force that tries to enter the pipe as shown in FIG. In FIG. 8, hatching of the pipe section of the stay portion 32 is omitted. When the punch 4 is rotated clockwise in FIG. 1, unnecessary deformation of the pipe is less likely to occur than in the case where the punch 4 is rotated counterclockwise, even if the punch 4 is also rotated. In fact, when the punch 4 is rotated clockwise in FIG. 1 and the punch 4 is lowered to preform the concave portion 2, the necessary concave portion 20 can be formed without deforming in unnecessary places. Have confirmed. It is considered that the direction of the resultant force when the punch 4 comes into contact with the peripheral surface corresponding to the concave portion forming portion M of the stay portion 32 is most effective in forming the concave portion when passing through the central axis of the pipe. In that case, in consideration of the rotational force of the punch 4 that generates the centrifugal force, it is preferable that the punch 4 be pressed against the concave portion forming portion M and lowered at a considerably high speed adapted thereto.

The outer peripheral portion 4 a of the punch rotates and presses the recess M at the stay portion 32, thereby forming the pipe 32.
8, a force G3 directed toward the inside of the pipe is applied. However, since the inside of the pipe is hollow O, the force is well absorbed and absorbed while being recessed 20 inside the pipe.
The pipe thickness t is not scraped off, and there is no risk of cracks or the like occurring in the pipe material. Thus, when the punch 4 that has been rotated while being pressed against the stay portion 32 passes through the recess forming portion M, a preformed recess 20 as shown in FIG. 3 is formed. Indentation with the 20 formation of the can portion F ₁ bulge to the stay portion inner periphery of the recess forming portion M. FIG. 3A is a cross-sectional view of the stay portion, and FIG. 3B is a vertical cross-sectional view of the stay portion. As described above, the outer peripheral portion of the punch 4 adopts a side view shape slightly smaller than the concave portion 2, and a concave portion 20 close to the concave portion 2 is obtained as shown in FIGS. 3 and 7. It is desirable that the shape of the concave portion 2 to be obtained as close as possible is as close as possible. This is because the present embodiment employs shaving processing as the second step, and the smaller the margin, the better the result.

After the recess 20 is formed, the punch 4 is retracted while the holder 11 for fixing and holding the stay portion 32 is left as it is. Subsequently, the holder cover 12 is attached to the holder 11 (FIG. 4).

Thereafter, the final recess 2 is formed by press working using a press punch 8. Pressing here employs shaving as described above. Shaving is generally performed by shaving the cut face with a press punch, and is said to provide a smooth and high-precision shearing surface. The present invention provides a recess 20 corresponding to the shape of the recess 2.
The presser punch 8 is used to scrape off the margins, thereby ensuring a highly accurate shear surface. Of course, unlike the blanking by the normal press punch 8, since the stay portion 32 is formed of a pipe, a part of the force of the press punch 8 is absorbed into the pipe while being recessed 20 in the process of punching with the press punch 8. Will do. Therefore, when the press punching is finished, the stay portion inner periphery of the recess engaging portion M can portion F ₂ swell bit larger inward than the portion F ₁ bulge made of a punching process (FIG. 7).

In the shaving process, the upright surface forming portion 81 of the blade portion 8a stands on the outer peripheral surface of the stay portion 32 to form the concave portion 2 in a shape orthogonal to the outer peripheral surface 32a of the stay portion 32. A sharp raised surface 21 is formed, and the function as a stopper can be exhibited. Further, since the vertical surface forming portion 81 and the bottom surface forming portion 82 of the blade portion 8a form a corner portion that intersects at right angles, the portion where the vertical surface 21 and the bottom surface 23 of the concave portion 2 cross has a sharp shape without a curved surface. Finish.

Thus, by punching out with the press punch 8, the clearance of the recess 20 is removed (FIG. 4). Although a part of the margin is cut off, the remaining part is recessed into the pipe so that the margin is removed. Since the convex dimension of the blade portion 8a of the press punch 8 is substantially equal to the dimension of the concave portion 2,
(FIG. 5), the desired recess 2 as shown in FIGS. 6 and 7 is formed by shaving using the press punch 8.

According to the method of processing the recess of the headrest stay configured as described above, the preliminary forming by the punch 4
Since the recess 20 close to the recess 2 can be obtained without performing the cutting process, the margin to be cut in the finishing stage of the recess shape by the subsequent press working can be extremely small. The thickness t can be sufficiently ensured even in the concave portion 2, and even when the concave portion 2 having the height adjusting function is formed in the stay portion 32, it can serve as a holding member. It is no longer necessary to increase the wall thickness of the pipe when relying on conventional cutting.

Further, since the headrest stay 3 made of pipe material is used to press the stay portion 32 while rotating the punch 4 to preform the concave portion 2, the pipe wall t is efficiently filled in the pipe O. The recess 20 for the concave portion which is pushed in is formed, and burrs do not occur. When the recess 20 is formed, no deformation occurs at unnecessary places. Since the desired concave portion 2 is finished by press working with the press punch 8, it can be formed into a sharp shape as a locking function required for the concave portion 2. Since the approximate shape of the concave portion 2 is formed by the first-stage preforming, no sagging or the like occurs. Further, when the shaving process using the press punch 8 is employed as in the embodiment, the concave portion 2 with high accuracy can be obtained. Moreover, there is no need for deburring or the like, so that simple and low-cost production is possible. In addition, because of the two-stage molding, the press molding time of each stage can be shortened. Then, in the same press equipment, the process shifts to the press working in the second step using the holder 11 for the preforming in the first step as it is, so that the total forming time can be shortened even in the two-stage forming.

In the present invention, the present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the present invention depending on the purpose and application. The shape, size, material, and the like of the holder 11, the holder cover 12, the recess 2, the headrest stay 3, the punch 4, the press punch 8, and the like can be appropriately selected within the scope of the present invention according to the application. In the embodiment, the shaving process is employed as the press process using the press punch, but the shaving process is an example and is not limited to this.

[0023]

As described above, the method for processing the concave portion of the headrest stay of the present invention forms a sharp concave portion while securing the required wall thickness, and can provide a simple, low-cost and excellent effect. I do.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of a preforming device in a first step in one form of a recess of a headrest stay.

FIG. 2 is an enlarged view of the punch of FIG.

FIG. 3 is an enlarged view around a concave portion after completion of preforming.

FIG. 4 is an explanatory sectional view of a press working device in a second step.

FIG. 5 is an enlarged view of the punch of FIG.

FIG. 6 is an enlarged view around the concave portion after the second step.

FIG. 7 is an explanatory cross-sectional view of the periphery of the recess relating to a stay portion where the periphery of the recess after the first step and the second step is overlapped.

FIG. 8 is an explanatory diagram showing directions of a combined force generated by a centrifugal force and a pressing force according to a rotational force.

FIG. 9 is a perspective view of a headrest incorporating the headrest stay with a recess in which the recess is formed in FIGS.

FIG. 10 is a view taken along line CC in FIG. 8;

FIG. 11 is an explanatory diagram of a conventional technique.

[Description of Signs] 11 Holder 12 Holder Cover 2 Depression 3 Headrest Stay 32 Stay Part 4 Punch 8 Press Punch M Depression-Forming Part (Part)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeki Eguchi 3-7-6 Dekimachi, Higashi-ku, Nagoya City, Aichi Prefecture Inside Arai Seisakusho

Claims (2)

[Claims] 1. A method of processing a recess of a headrest stay provided on a stay portion of a headrest stay made of a pipe material, wherein the punch is rotated and pressed against the stay portion to preform the recess, and thereafter, a press punch is formed. A method of forming a recess of a headrest stay, wherein the recess is formed by press working using a rubber. 2. A method of processing a concave portion of a headrest stay provided on a stay portion of a headrest stay made of a pipe material, wherein a portion of the stay portion provided with the concave portion is exposed, and a headrest stay is set on a holder. Pressing against the stay portion while rotating a disc-shaped punch whose side view shape of the outer peripheral part resembled the concave part, preformed the concave part, and then
A method of processing a concave portion of a headrest stay, comprising: attaching a holder cover to the holder; and forming a concave portion by pressing using a press punch.