JP2000218433A - Manufacturing method and device for metallic bar product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and a device for a metallic bar product, capable of efficiently forming in an engaging recessed part without any sagging or burrs in the outer peripheral part of a metallic bar. SOLUTION: In the manufacturing method of a metallic bar product, first, in its first step, a metallic bar K is held on the upper and lower die plates 7 and 13 of a press machine, upper and lower punches 6 and 12 provided to be movable vertically are pressed to the outer peripheral part of the metallic bar K to hold it between upper and lower sides, and a notched groove and an extra thick projected part are formed in the outer peripheral part of the metallic bar K. Then, in a second step, a punch 16 is slid from one direction into the notched groove formed in the first step, and by cutting off the extra thick projected part K2 by the punch 16, an engaging recessed part is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal rod having a locking recess formed on the outer periphery of a metal rod suitable for manufacturing a headrest support rod for a vehicle seat or a handle support rod for a vehicle handbrake. The present invention relates to a method and an apparatus for manufacturing a product.
Here, the metal rod is a concept including a hollow pipe and a solid rod.

[0002]

2. Description of the Related Art For example, a support rod of a headrest of a vehicle seat or a handle support rod of a handbrake of a vehicle is provided with a notch-shaped locking recess at a predetermined position on an outer peripheral portion of a solid or hollow metal rod. Is formed. When the headrest or the handbrake is pulled out or pushed in, the locking recess is locked by a projection provided on the seat or the vehicle body. At least one corner has an acute angle of about 90 degrees. Need to be formed with

[0003] For this reason, conventionally, for this type of processing, a milling cutter using a milling machine or a broach blade using a broaching machine has been used, and a locking concave portion has been formed at a predetermined position on the outer peripheral portion of the metal bar by cutting. However, although cutting with a milling machine or the like can be processed to an accurate shape, it takes a considerable amount of processing time and requires a polishing step to remove burrs generated by cutting, increasing the number of processing steps and increasing mass production. Had a problem that production efficiency was reduced.

In view of the above, in Japanese Patent Application Laid-Open No. Hei 8-90126, a press is used to hold a metal rod on a lower die, and a punch having a shape corresponding to the locking recess is placed on the metal rod from above. A method has been proposed in which an engaging recess is formed on the outer periphery of a metal rod by plastic deformation by pressing down and pressing.

[0005]

However, the formation of the locking recesses of the metal rod by the above-mentioned method is to press the locking recesses using a punch by pressing, that is, by pressing the punch onto the metal rod. The outer peripheral portion of the rod is plastically deformed so as to be crushed, and a locking concave portion is formed therein by depression. For this reason, as shown in FIG.
There has been a problem that sagging easily occurs at the corner 31 of the locking recess 30 that requires an acute angle.

The present invention has been made in view of the above points, and a method of manufacturing a metal rod product capable of efficiently forming a locking concave portion on the outer peripheral portion of a metal rod without causing sagging or burrs. And an apparatus thereof.

[0007]

In order to achieve the above object, a manufacturing method according to the present invention is directed to a method for manufacturing a metal bar product in which a locking recess is formed on the outer periphery of a metal bar using a pressing machine. A first step of pressing an upper punch and a lower punch movably provided on the outer peripheral edge of the metal bar so as to sandwich the upper punch and the lower punch from both upper and lower sides, and forming a notch groove and an extra protrusion on the outer peripheral edge of the metal rod. And a second step in which the punch is slid from one direction into the notch groove formed in the first step and the excess projection is scraped off by the punch to form a locking concave portion.

Further, the manufacturing apparatus of the present invention is a metal rod product manufacturing apparatus in which a locking recess is formed on the outer periphery of a metal bar by using a press machine.
A processing stage for the first step and a processing stage for the second step are provided. The processing stage for the first step includes a die plate for holding a metal rod, and an outer peripheral edge of the metal rod held by the die plate. An upper punch and a lower punch are formed on the outer peripheral edge of the metal bar to form a notch groove and an extra protrusion on the outer periphery of the metal bar. A die plate for holding the metal rod processed in the step, and a punch for sliding in one direction into the notch groove of the metal rod formed in the first step to cut off the excess protrusion and form a locking recess Are disposed.

[0009]

In the method of manufacturing a metal bar product having such a configuration, first, in a first step, a metal bar is held on a die plate of a press machine, and an upper punch which is vertically movable is provided. The lower punch is pressed against the outer peripheral edge of the metal bar so as to sandwich the lower punch from both the upper and lower sides, and a notch groove and extra protrusion are formed on the outer peripheral edge of the metal bar. Next, in the second step,
The punch is slid from one direction into the notch groove formed in the first step, and the excess protrusion is scraped off by the punch to form a locking recess.

As described above, first, in the first step, the upper punch and the lower punch are pressed against the outer peripheral edge of the metal rod so as to be sandwiched from both upper and lower sides, and the notch groove and the extra protrusion are formed on the outer peripheral edge of the metal rod. Is formed, the blade portion of the punch is pushed into the outer peripheral edge of the metal bar in a direction perpendicular to the axial direction of the bar, and enters so as to scrape the edge. Therefore, burrs do not occur at the pushed-in portions, and corners of the notched grooves do not sag. In other words, in the cross section of the notch groove along the axial direction of the metal rod, the shape of the blade portion of the upper punch and the lower punch accurately appears, and the corner of the notch groove has a good corner having an acute angle of about 90 degrees. Further, since the shaving process by the upper punch and the lower punch is stopped at the intermediate position of the notch portion, the shape of the notch groove does not deteriorate near the exit of the blade portion.

Then, in the next second step, the punch is slid from one direction into the notch groove formed in the first step, and the extra protrusion is cut off by the punch to form a locking concave portion. Cutting only removes the excess protrusion, and does not cause any deformation of the shape of the locking concave portion.

Therefore, at the time of the first step, the outer peripheral edge of the metal rod is pushed in from both sides so as to sandwich it, so that the notch groove is formed. There is no occurrence, and the corner of the notch groove has an acute angle of about 90 degrees, so the locking recess formed by cutting off the excess projection also has no burrs at the end and sagging of the corner, It is possible to form an accurate and good shape engaging recess.

Further, if a working stage for the first process and a working stage for the second process are provided between the bolster and the slide of one press machine as in the above-mentioned manufacturing apparatus, the operation of the press machine in one process can be achieved. Thus, one metal rod product can be manufactured efficiently.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view of a press machine for forming a locking recess K3 on a metal bar K used for a support bar of a headrest of a vehicle seat or a handle support bar of a vehicle handbrake. In this press machine, two processing stages, a processing stage 3 for a first process and a processing stage 4 for a second process, are mounted between the bolster 1 and the slide 2.

In the processing stage 3 for the first step, 5
Is an upper die fixed to the lower side of the slide 2, and an upper punch 6 having a groove forming blade is attached below the upper die 5. As shown in FIG. 4, the upper punch 6 is formed in a shape corresponding to the cross-sectional shape along the axial direction of the locking concave portion K3 formed in the metal rod K, and the upper punch 6 is provided by the number (three in this case). .

Reference numeral 7 denotes an upper die plate which is mounted on the periphery of the upper die 5 so as to be vertically movable with a slight width, and is mounted via a coil spring 11. The lower part of the upper die 5 and the upper punch 6 It is slidably fitted into an opening provided inside the plate 7. On the lower surface of the upper die plate 7, a concave portion (groove) for holding a metal rod K to be processed at a predetermined position corresponding to the upper punch 6 is formed.

On the bolster 1 located below, a slide die 8 is disposed so as to be movable in the horizontal direction. On a cam surface formed on the slide die 8, a lower die 9 is provided with a cam surface on its lower surface. Are disposed in contact with each other. A lower punch 12 having a blade for forming a groove is attached to the upper part of the lower die 9 similarly to the upper punch 6. The lower punch 12 has a blade portion having the same shape as the upper punch 6 symmetrically, and is provided in the same number as the upper punch 6 so as to face the upper punch 6. A passive cam surface is formed at the right end of the slide die 8, and the lower cam surface of the fixed cam 10 is disposed on the passive cam surface so as to be in contact with the passive cam surface.
Is fixed to the lower side of the slide 2.

Reference numeral 13 denotes a lower die plate fixed on the bolster 1 so that the upper part of the lower die 9 and the lower punch 12 can slide through an opening provided inside the lower die plate 13 via a coil spring 14. It is inserted. A concave portion is formed on the upper surface of the lower die plate 13 for holding the metal bar K as a workpiece at a predetermined position corresponding to the lower punch 12. A support frame plate 15 is attached to the side of the mold holding block that holds the periphery of the upper mold 5, and the upper portion of the lower die plate 13 slidably enters the support frame plate 15.

When the metal bar K is a support bar for a headrest of a vehicle seat, the metal bar K is bent in a substantially U-shape. In FIG. 1, reference numeral 28 in FIG. The holding portion 29 is a holding portion for holding the holding portion from above.

In the working stage 3 for the first step, the fixed cam 10 is lowered with the slide 2 being lowered, and accordingly, the slide die 8 is moved to the left, whereby the lower die 9 and the lower punch 12 are moved. To rise. At the same time, the upper die plate 7, the upper die 5, and the upper punch 6 descend. The upper die plate 7 descends first to hold the metal bar K in the concave portion of the mating surface, and the upper and lower upper punches 6 and lower punches 12 move up and down with a slight delay, so that the first process is performed. .

By the lowering of the upper punch 6 and the raising operation of the lower punch 12, a notch groove K1 and an extra protrusion K2 are formed on the outer peripheral edge of the metal rod K. As shown in FIG. As the lower punch 12 is pushed into the metal bar K with a slightly shorter stroke than the upper punch 6, the upper die 5 is formed so that K2 is formed slightly below the center axis of the metal bar K.
The movement timing of the lower die 9 is adjusted.

A processing stage 4 for the second process is disposed adjacent to the processing stage 3 for the first process. In the processing stage 4 for the second step, reference numeral 18 denotes an upper die fixed to the lower side of the slide 2, and a punch 16 having a cutting blade is attached below the upper die 18. The punches 16 are formed in the same shape as the upper punch 6 for the first step, and are the same in number as the number of the locking recesses K3 formed in the metal rod K (here, three).
It is attached.

An upper die plate 17 is mounted around the upper die 18 so as to be able to move up and down with a small width. The upper die plate 17 is mounted below the upper die 18 via a coil spring 21.
And the punch 16 are slidably fitted into an opening provided inside the upper die plate 7. Upper die plate 1
7, a metal rod K to be processed is placed on a punch 16.
A concave portion (groove) for holding at a predetermined position corresponding to.

A lower die plate 23 is fixed on the lower bolster 1 via a fixing block 19. A groove for holding the metal bar K of the workpiece is formed on the lower die plate 23, and an opening is formed adjacent to the groove to allow the tip of the upper die 18 and the punch 16 to enter. On the left side of the upper die plate 17 and the lower die plate 23 in FIG. 1, a holding portion 28 that holds the non-processed side of the U-shaped metal bar K from below,
A holding unit 29 for holding the unit from above is provided.

Next, a description will be given of a method of manufacturing a metal rod which is carried out by using the press having the above-described structure. First, with the slide 2 raised and the upper die 5 and the lower die 9 opened, the metal rod K of the workpiece is placed at a predetermined position in the groove of the lower die plate 13. The press machine operates and the slide 2 descends by a predetermined stroke.

At this time, first, the lower surface of the upper die plate 7 and the upper surface of the lower die plate 13 are in contact with each other, and the metal bar K is held in the groove therebetween. At a slightly delayed timing, the upper die 5 and the upper punch 6 descend, and the lower die 9 and the lower punch 12 rise by the action of the fixed cam 10 and the slide die 8, and the blades of the upper punch 6 and the lower punch 12 The portion descends and rises so as to press and pinch a predetermined position of the outer peripheral edge of the metal rod K. As a result, as shown in FIGS. 2A and 2B, a notch groove K <b> 1 and an extra thickness protrusion K <b> 2 are formed at an intermediate portion of the notch groove K <b> 1 on the outer peripheral edge of the metal bar K.

More precisely, as shown in FIG.
Is slightly longer than the rising stroke of the lower punch 12, the excess protrusion K2 is formed slightly below the center position of the cutout groove K1.

Then, the upper die 5,
The first step is completed by the lower mold 9 returning to the original position,
The blades of the upper punch 6 and the lower punch 12 enter and push into the outer peripheral edge of the metal rod K in such a way as to cut off the edge in a direction perpendicular to the axial direction of the rod, so that burrs occur at the pushed-in locations. Also, the corners of the cutout groove K1 do not sag. That is, in the cross section of the notch groove K1 along the axial direction of the metal rod K, the shapes of the blade portions of the upper punch 6 and the lower punch 12 accurately appear, and as shown in FIG. The part has an acute angle of about 90 degrees.

Further, since the shaving process by the blade portions of the upper punch 6 and the lower punch 12 is stopped at an intermediate position between the notches, no burrs are generated at the lower ends of the notches. Furthermore,
In the first step, since the blade portions of the upper punch 6 and the lower punch 12 are pushed into the outer peripheral edge of the metal rod K in a tangential direction of the rod cross section, plastic flow of the material occurs inside the notch groove K1,
When the metal rod K is a tube material, the lower side of the notch groove K1 swells slightly inward and its thickness becomes slightly thicker, so that the strength of the portion does not decrease and a relatively thin tube material is used. It can be used and material costs can be reduced.

Next, the metal rod K that has completed the first step is transferred to the processing stage 4 for the second step, and is placed in the groove of the lower die plate 23. A new metal rod K is placed in the groove on the lower die plate 13 on the processing stage 3 for the first step. Then, as described above, the press machine is operated again, and the slide 2 is lowered by a predetermined stroke.

At this time, first, the lower surface of the upper die plate 17 and the upper surface of the lower die plate 23 are in contact with each other, and the metal bar K is held in the groove therebetween. And at a slightly delayed timing,
The upper die 18 and the punch 16 descend, and the blade portion of the punch 16 accurately enters the cutout groove K1 on the outer peripheral edge of the metal rod K. Thereby, as shown in FIGS. 2C and 2D, the notch groove K1
The inner excess projection K2 is scraped off, and a locking recess K3 having a predetermined shape as shown in FIGS. 4C and 4D is formed on the outer peripheral edge of the metal rod K. Since the cutting by the punch 16 only removes the excess protrusion K2, the deformation of the shape of the locking recess K3 does not occur at all.

Therefore, as described above, in the first step, the outer peripheral edge of the metal rod K is pushed in so as to sandwich it from both sides to form the notch groove K1, and burrs are generated at both ends of the notch groove K1. Also, there is no dripping at the corners of the notch groove K1 and the corners of the notch groove K1 have an acute angle of about 90 degrees. The locking recess K3 thus formed does not have burrs at the ends or sagging at the corners, and can form the locking recess K3 having a precise and favorable shape.

Also, as described above, one press machine:
Processing stage 3 of the first process and processing stage 4 of the second process
Is provided, it is possible to process and form the locking recess of one metal bar product in one stroke operation of the press machine.

FIG. 5 shows the processing steps of another embodiment. In this example, a press having a structure in which a punch 46 having the same shape as the upper punch 6 is attached to the upper die and only the lower die plate is provided on the lower side is used for the processing stage in the first step. In the processing stage of the second step of the press machine,
A punch 56 similar to the lower punch 12 is attached to the lower die, and only the upper die plate is provided on the upper side.

When the processing shown in FIG. 5 is performed, in such a press machine, a metal is placed in a predetermined position of the workpiece in the groove of the lower die plate with the upper die and the lower die plate being opened in the first step. The bar K is placed, the press is operated, and the slide is lowered by a predetermined stroke.

At this time, first, the upper die plate and the lower die plate come into contact with each other, the metal bar K is held in the groove between them, and at a slightly delayed timing, the upper die and the punch 46 are lowered, and the blade of the punch 46 is cut. The part presses a predetermined position on the outer peripheral edge of the metal rod K, moves down to an intermediate position (slightly below the axial position of the metal rod K), and rises. As a result, FIG.
As shown in (b), a notch groove K5 is formed on the outer peripheral edge of the metal rod K.
Is formed, and an excess protrusion K4 is formed below the cutout groove K5.

At this time, the blade portion of the punch 46 is pushed into the outer peripheral edge of the metal bar K in a direction perpendicular to the axial direction of the bar, as described above, so that no flash occurs at the pushed-in portion. Further, the corners of the cutout groove K5 do not sag. That is, in the cross section of the notch groove K5 along the axial direction of the metal rod K, the shape of the blade portion of the punch 46 appears accurately, and the corner of the notch groove K5 has an acute angle of about 90 degrees.
Further, since the shaving process by the blade portion of the punch 46 is stopped at the intermediate position of the notch portion, no burr is generated at the end of the notch portion.

Next, the metal rod K, which has completed the first step, is transferred to a processing stage for the second step, placed in the groove of the die plate below it, and operated again by the press to operate the second step. Is carried out. That is, the upper die plate and the lower die plate are in contact with each other, the metal bar K is held in the groove between them, and at a slightly delayed timing, the lower die and the punch 56 rise, and the blade of the punch 56 From the lower side of the outer peripheral edge of K, it rises so as to scrape off excess projection K4. As a result, as shown in FIGS. 5 (c) and 5 (d), the excess protrusion K4 on the outer peripheral edge of the metal rod K is cut off, and the locking recess K3 is formed there. Since the cutting by the punch 56 only removes the excess protrusion K4, no deformation of the shape of the locking concave portion K3 occurs.

Accordingly, in the same manner as described above, in the first step, since the notch groove K5 is formed by pushing in from one of the outer peripheral edges of the metal rod K, burrs do not occur at the end of the notch groove K5. In addition, no dripping occurs at the corners of the cutout groove K5, and the corners of the cutout groove K5 have an acute angle of about 90 degrees. The concave portion K3 is also free from burrs at the ends and sagging at the corners, and can form the locking concave portion K3 having a good and accurate shape.

In the embodiment shown in FIG. 5, in the second step, the punch 56 is lifted from below and the extra protrusion K4 is formed.
However, in the second step, the metal rod is inverted and placed on the groove of the die plate in the reverse of the first step, and a punch having a symmetrical shape with the punch 56 is fixed to the upper mold, and the punch By lowering, the excess protrusion K4 can be scraped off. Further, as the metal rod, a solid round rod can be used in addition to the tube material as in the above two embodiments.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a press for performing a manufacturing method according to an embodiment of the present invention.

FIG. 2 is an explanatory sectional view showing a processing step of a metal rod.

FIG. 3 is an enlarged sectional view showing a relationship between a punch and a metal rod.

FIGS. 4A and 4B are a front view and a plan view of the metal rod when the first step and the second step are completed.

FIG. 5 is an explanatory sectional view showing a processing step of a metal rod according to another embodiment.

FIG. 6 is a sectional view of a locking recess of a metal rod processed by a conventional method.

[Explanation of symbols]

 1-bolster 2-slide 3-first processing stage 4-second processing stage 6-upper punch 7-upper die plate 12-lower punch 13-lower die plate 16-punch K-metal rod K1-notched groove K2 -Excess protrusion K3-locking recess

Claims (3)

[Claims] 1. A method of manufacturing a metal bar product in which a locking recess is formed on an outer periphery of a metal bar by using a press machine, wherein an upper punch and a lower punch provided in the press machine so as to be movable up and down are connected to the metal bar. A first step of pressing the outer peripheral edge so as to sandwich it from both upper and lower sides to form a notch groove and an extra protrusion on the outer peripheral edge of the metal rod, and a punch in the notch groove formed in the first step. A second step of forming a locking concave portion by sliding the excess protrusion with the punch by sliding from one direction. 2. A method of manufacturing a metal bar product in which a locking recess is formed on an outer periphery of a metal bar using a press machine, wherein a first punch provided on the press machine is provided on one side of an outer peripheral edge of the metal bar. A first step of forming a notch groove and an extra projection on the outer peripheral edge of the metal rod; and a second punch provided in a press machine, the extra projection formed in the first step. A second step of pressing against the other side to form a locking recess by shaving off the excess protrusion with the second punch. 3. An apparatus for manufacturing a metal bar product in which a locking recess is formed on the outer periphery of a metal bar using a press machine, wherein a processing stage for a first process and a second process are provided between a bolster and a slide of the press machine. A processing stage for the first step is provided on the processing stage for the first step, and a die plate for holding the metal bar and a metal plate held by the die plate are pushed from both upper and lower sides to the outer peripheral edge of the metal bar. An upper punch and a lower punch forming a notch groove and an extra protrusion on the outer peripheral edge of the metal rod, and the processing stage for the second step includes a metal processed in the first step. A die plate for holding a rod, and a punch for sliding into the notch groove of the metal rod formed in the first step from one direction to cut off the excess protrusion to form a locking recess are arranged. An apparatus for manufacturing a metal bar product, which is provided.