JP2644456B2 - Belt connection bracket and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal fitting for connecting a belt such as a safety belt and a method of manufacturing the same, and more particularly to a metal fitting for connecting a belt such as a safety belt and the like that effectively prevents the belt from being cut or broken. .

[0002]

2. Description of the Related Art Generally, a seat belt device as a safety belt device is provided on a vehicle body or a seat of an automobile.
In this seat belt device, a seat belt in which a fiber material such as a synthetic fiber is woven in a belt shape is used as webbing. A belt connection fitting is used to connect the seat belt to a vehicle body or a seat of an automobile.

[0003] A belt connecting bracket is formed by punching a steel plate into a predetermined shape and forming a belt insertion hole in a part thereof.
It is used by fixing the belt connecting bracket to the body or seat of an automobile. In this type of belt connection bracket,
Anchor fittings, through anchor fittings, tongue plates, etc. are available.

[0004] The conventional belt connecting bracket is formed by punching and press-forming a belt insertion hole in a metal plate made of steel plate. When the metal plate is punched, burrs are generated at the edge of the belt insertion hole, and the blade shape due to the burrs is generated. Is formed, deburring is performed, and the cross-sectional structure of the edge of the belt insertion hole is made smooth.

[0005] In order to make the cross-sectional structure of the belt insertion hole of the metal plate smooth, a corner portion of the inner edge of the belt insertion hole is ground by a grinder to form a round portion, or the inner edge of the belt insertion hole is coated with a resin. Or the cross-sectional structure is smooth. However, in the conventional belt connection bracket, since the thickness of the bracket plate is increased due to processing cost and material restrictions, a sheet to be inserted into the belt insertion hole is used. Since the belt is pulled in a point contact or a line contact with a local portion of the belt insertion hole, the seat belt may be cut or broken at the contact portion.

In order to prevent the seat belt from being cut or broken, a belt connecting fitting disclosed in Japanese Utility Model Laid-Open No. 2-120272 has been developed.

In this belt connection metal fitting, the edge of the belt insertion hole formed in the metal plate is molded using an upper die and a lower die, and the edge of the belt insertion hole is bulged to one side of the plate. The edge cross section of the belt insertion hole has a semi-circular cross-sectional structure, and the seat belt inserted into the belt insertion hole makes surface contact with the semi-circular edge of the belt insertion hole, and the seat belt is cut or broken. Is prevented from doing so.

[0008]

In the conventional belt connecting metal fitting, the edge of the belt insertion hole of the metal plate is bulged to one side of the plate by molding with an upper die and a lower die, and the edge of the belt insertion hole is formed. Is formed into a semicircular cross-sectional structure, but since the mating surface of the upper and lower dies is located at the center in the thickness direction of the belt insertion hole, burrs generated on the mating surface of the upper and lower dies are removed. In addition to the need for post-processing, the belt insertion hole edge of the metal plate only swells to one side of the plate, so the seat belt pulling force does not act on the metal plate in a balanced manner, or the belt insertion hole The radius of curvature of the semicircular cross section formed at the edge cannot be large, and the seat belt is inserted into the edge of the belt insertion hole with a small radius of curvature. Break or cut Was difficulties in effectively prevented.

The present invention has been made in view of the above-described circumstances, and increases the radius of curvature of the edge of the belt insertion hole of the metal plate to increase the surface contact area of the belt, thereby effectively cutting or breaking the belt. It is an object of the present invention to provide a belt connecting metal fitting which is prevented reliably and reliably, and a method of manufacturing the same.

Another object of the present invention is to provide a belt in which the tensile force of the seat belt acts on the metal plate in a well-balanced manner, so that post-processing such as deburring to the belt engaging side edge of the belt insertion hole of the metal plate is unnecessary. An object of the present invention is to provide a connection fitting and a method of manufacturing the same.

It is still another object of the present invention to provide an inexpensive metal fitting for connecting a belt, which can eliminate the need for resin coating around a belt insertion hole of a metal fitting plate, and a method of manufacturing the same.

[0012]

According to a first aspect of the present invention, there is provided a belt connecting bracket having a plate mounting hole and a belt insertion hole formed in a metal plate. In a belt connection fitting configured so that a seat belt can be attached to the belt insertion hole, the belt insertion hole of the metal plate is punched and formed with at least an over clearance at a belt engaging side edge. The belt insertion hole of the bracket plate
At least the belt engaging side edge is pressed and expanded by an expanding punch and a die, and then formed by a forming punch and a forming die to form a swelling portion which swells on both sides of the metal plate. Is formed in a substantially circular curved cross-sectional structure in which the bulging portion forming side edge bulges to both sides of the plate.

According to a second aspect of the present invention, there is provided a method for manufacturing a belt connecting metal fitting, wherein a plate mounting hole and a belt insertion hole are formed in a metal plate as described above. In the method of manufacturing a belt connection metal fitting for manufacturing a belt connection metal fitting, when the belt insertion hole is formed in the metal fitting plate, at least a part of the working punch and the die have an over clearance to form the belt insertion hole. Then, while expanding the sheared cross section on the over-clearance side of the perforated belt insertion hole with the expanding punch, pressing and deforming the entire surface of the plate, and then pressing the forming punch from the entire surface of the plate to form the belt. Pushing back the deformed side edge of the insertion hole while rolling it in, it swells to the other side of the plate, and the belt insertion hole is formed by the concave curved forming surface of the forming punch and the forming die facing each other. Part molding the bulge bulging plate both sides to a method of forming the bulging portion forming the side edge portion as a belt engaging side edge portion of the belt insertion hole.

Further, in order to solve the above-mentioned problems,
A method for manufacturing a belt connection fitting according to the present invention is described in claim 3.
As described in the above, when forming the belt insertion hole of the metal plate with the forming punch and the forming die, at least the wall of the belt engaging side edge of the belt insertion hole is displaced so as to be rolled from the center portion to both sides of the plate. Then, the bulging portion forming side edge of the belt insertion hole is formed into a substantially circular curved cross-sectional structure.

[0015]

In the belt connection metal fitting according to the first aspect, the belt insertion hole of the metal plate is formed by swelling at least a portion of the belt engaging side edge to form a bulge on both sides of the plate. The bulging hole forming side edge has a substantially circular curved cross-sectional structure, so that the seat belt pulling force acts on the metal plate in a balanced manner, and the radius of curvature of the belt engaging side edge of the belt insertion hole is increased. It is possible,
In addition, a smooth surface contact can be made with a large contact area with the seat belt, and the cutting and breaking of the belt can be effectively and reliably prevented.

The belt insertion hole of the metal plate has well-balanced bulging portions formed at least on both sides of the plate at the side edge of the belt engagement side, and the belt engaging holes of the belt insertion holes are formed using the bulging portions protruding on both side surfaces of the plate. Since the mating side edge has a substantially circular curved cross-sectional structure, it is not necessary to build up the resin coating for eliminating the inner edge corners of the belt insertion hole, and it is possible to manufacture the belt connecting bracket at low cost.

According to a second aspect of the present invention, there is provided a method for manufacturing a belt connecting metal fitting, wherein at least a part of a punch and a die are provided with an overclearance, and a metal plate is punched out to form a belt insertion hole. While expanding the shear rupture surface on the over clearance side of the belt insertion hole with the expanding punch, it is pressed and deformed to one side of the plate,
Pressing the forming punch from one side of the plate and rolling it back while rolling in the deformed side edge of the belt insertion hole, swelling to the other side of the plate, and forming the swelling part with the concave curved forming surface facing the forming punch and the forming die. Molded on both sides of the plate, and the bulging portion forming side edge was the belt engaging side of the belt insertion hole, so that the belt engaging side edge of the belt insertion hole became a bulging portion projecting to both sides, and the belt insertion The radius of curvature of the belt engaging side edge portion of the hole can be made large, and the surface can be brought into smooth contact with the seat belt with a large contact area, so that cutting and breaking of the seat belt can be effectively and reliably prevented.

Further, in the method for manufacturing a belt connection metal fitting according to the third aspect, the belt insertion hole of the metal plate is formed such that at least the thickness of the belt engaging side edge portion of the forming punch and the forming die is from the center to the both sides of the plate. Since burrs are formed so as to be wound around, no burrs are generated at least at the belt engaging side edges of the belt insertion holes, and post-processing such as deburring is unnecessary, which is economical.

[0019]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show an example in which the belt connecting fitting according to the present invention is used as an anchor fitting of a seat belt device fixed to a vehicle body of an automobile.

The belt connecting metal fitting 10 has a metal fitting plate 11 made of a steel plate such as high-tensile steel. Hardware plate 1
1 is formed by stamping and forming a strip-shaped steel plate, and has a plate mounting hole 12 through which an anchor bolt (not shown) is inserted and a belt insertion hole 14 through which a seat belt 13 can be inserted. After the metal plate 11 has formed the plate mounting hole 12 and the belt insertion hole 14, it is bent along the bending line L at a predetermined angle θ, for example, 60 degrees or less, preferably about 35 degrees. The bending line L is related to the belt insertion hole 14 and straddles the belt insertion hole 14.

The belt insertion hole 14 formed in the metal plate 11 is formed in a long hole shape extending in the width direction of the metal plate, and at least the belt engagement side edge of the belt insertion hole 14 is expanded in a well-balanced manner on both sides of the plate. Outgoing parts 15a, 15b
Is formed, and the cross-sectional shape of the belt engaging side edge is configured to be a smooth curved cross-sectional structure having a substantially circular shape.

As shown in FIG. 3, the belt insertion hole 14 of the metal plate 11 is formed such that the flesh of the belt engaging side edge is raised on both sides of the plate, and the belt engaging side edge is well balanced on both sides of the plate on the belt engaging side edge. The bulging portions 15a and 15b are formed respectively, and the belt engaging side of the belt insertion hole 14 is formed into a curved cross-sectional structure having a smooth curved portion 16 having a substantially circular cross-section by using the bulging portions 15a and 15b. doing. Thereby, the radius of curvature R of the substantially circular curved surface of the belt engaging side edge of the belt insertion hole 14 can be increased, and the plate thickness can be reduced without increasing the thickness (plate thickness) of the metal plate 11. It is equivalent to a larger one, and engages with the seat belt 13 inserted through the belt insertion hole 14 with a smooth surface contact having a large contact area.
Can be effectively and reliably prevented from being cut or damaged, and the durability of the seat belt 13 can be improved.

The belt insertion hole 1 of the metal plate 11
Reference numeral 4 denotes bulging portions 15a, 15b bulging to both sides of the plate at least at the edge of the belt engaging side, and using these bulging portions 15a, 15b, a curved portion having a substantially circular cross section is formed on the belt engaging side. 16 are formed. Since the curved portion 16 is formed to have a large radius of curvature by protruding on both sides of the plate, it is equivalent to forming a rib smoothly continuous with the inner edge of the belt insertion hole on both sides of the plate of the belt insertion hole 14, Wear and cutting of the belt 13 can be effectively prevented, and the durability of the seat belt 13 is improved. Reference numeral 17 denotes a space for engraving, and reference numeral 18 denotes a space for a lot number.

Further, the metal plate 11 of the belt connecting metal 10A used for the anchor metal is shown in FIGS.
As shown in the above, the bending angle .theta.1 may be bent, for example, from 60 to 90 degrees, preferably about 90 degrees. At this time, the belt insertion hole 14 formed in the metal fitting plate 11 may be formed in a curved shape so that the center in the longitudinal direction of the belt engaging side edge projects toward the opposite side edge of the insertion hole.

Next, a description will be given of an apparatus and a method for manufacturing a metal fitting for belt connection.

FIG. 6 shows an apparatus for manufacturing the metal fitting for belt connection.
The stamping type continuous press machine 20 shown in FIG. The press machine 20 includes a fixed lower mold 21 and a movable upper mold 22.
Having a die set 23 composed of
A die plate 24 is fixed on the lower die 21, and a strip-shaped steel plate 25 to be formed is placed on the die plate 24. The belt-shaped steel plate 25 is formed by forming a steel plate such as a high-strength steel, and forming the metal plate 11 in a belt shape at a predetermined pitch so as to be continuous in a row through the weakened region.

A punch fixing plate 27 is fixed to the upper die 22 of the die set 23 via a packing plate 26 made of hardened steel.
The stripper plate 29 is elastically supported by the plate holder 30 via a plurality of springs 28 formed of a multilayer disc spring or the like. The stripper plate 29 is always urged downward by a plurality of springs 28 provided on both sides.

A punch 31, a working punch 32, an expanding punch 33, and pilots 34, 35 are arranged and fixed in a row at required intervals on a punch fixing plate 27 fixed to the upper die 22 of the die set 23. You. Punch guide holes 37, 38, 39 and pilot guide holes 40, 41 for guiding the punching punch 31, the working punch 32, the pilot 34, the expanding punch 33, and the pilot 35 fixed to the punch fixing plate 27 are respectively provided on the stripper plate 29. While being formed, the die plates 24 face the punch guide holes 37, 38, 39 and the pilot guide holes 40, 41 of the stripper plate 29, and the die holes 43, 44, 45 and the pilot guide holes 46,
47 are formed.

Thus, a punch and a die are formed by the die plate 24 having the die holes 43, 44, and 45, the punch 31, the working punch 32, and the expanding punch 33 fixed to the punch fixing plate 27. Punching and shaping processes are performed.

The press machine 20 is provided with a forming punch 50 and a forming die 51 made of cemented carbide on the downstream side of the expanding punch 33 and the die 45. While the forming punch 50 is fixed to the lower mold 21 of the die set 23, the forming punch 5
Numeral 0 guides up and down movement of a movable table 53 elastically supported by a spring 52 such as a multilayer disc spring. On the other hand, the molding die 51 is provided with the packing plate 2 on the upper die 22 of the die set 23.
6, and is incorporated in a fixed base 54 fixed.
A pilot 55 for positioning the metal plate 11 is fixed to the fixing table 54.
5 is guided by a pilot guide hole 56 formed in the movable base 53.

Further, the forming punch 5 is
On the downstream side of the die 0 and the die 51, there are provided a work forming punch and a die (both not shown) for cutting the strip-shaped steel plate 25 into individual fitting plates 11 and imparting a required angle of bending.

In this press machine 20, a punch 31 is used.
Then, a plate mounting hole 12 is formed by punching a metal plate 11 of a strip-shaped steel plate 25 by a die of a die plate 24 by lifting and lowering an upper die 22.

A plate mounting hole 12 is formed in the metal plate 11.
The strip-shaped steel plate 25 in which is drilled is sequentially fed by one pitch P of the metal plate 11. The upper die 22 moves down by a required stroke while the belt-shaped steel plate 25 is fed by a predetermined pitch,
The pilot 34 is inserted into the drilled plate mounting hole 12 to position the bracket plate 11 and
This metal plate 11 is punched out by the working punch 32 and the die 60 of the die plate 24 to form the belt insertion hole 1.
4 are drilled. At this time, the following metal plate 11
The plate mounting hole 12 is punched and formed by the punch of the punch 31 and the die of the die plate 24.

Working punch 3 formed on press machine 20
7 and the die 60 on the die plate 24 are configured as shown in FIG. 7. The clearance δ between the processing punch 32 and the die 60 is not uniform over the entire circumference of the belt insertion hole 14, A portion, for example, a belt engaging side is formed with an overclearance δ1. The over clearance δ1 has a gap of 10% to more than 20%, preferably about 15% to 20%, with respect to the plate thickness (thickness: for example, 3.2 mm) of the strip-shaped steel sheet as a processing material, and the belt is inserted. The remaining portion of the hole 14 has an appropriate clearance .delta.2, for example, a plate thickness ratio of 5% to 10%, preferably 5% to 6%.
% Gap.

The belt insertion hole 14 is formed by punching the metal plate 11 of the strip-shaped steel plate 25 with the working punch 32 and the die 60, and a relief groove 61 is formed in the die 60 on the belt engaging side during the punch forming process. Then, the belt engaging side edge of the belt insertion hole 14 formed by the working punch 32 and the die 60 is slightly pressed and deformed toward the one surface (lower surface) side of the plate, so that the plate material of the belt engaging side edge, especially the plate, etc. The plate material on the front (top) side is stretched.

Subsequently, as shown in FIG.
After the belt insertion hole 14 is formed in the metal plate 11 part, the upper die 22 is moved up by a required stroke so that the working punch 32 and the pilot 34 are connected to the metal plate 1 of the belt-shaped steel plate 25.
It is pulled out from one part of the belt insertion hole 14 and the plate mounting hole 12. After this drawing, the strip-shaped steel plate 25 is sequentially fed by one pitch, the upper die 22 is again moved down by a required stroke, and the pilot 35 is fitted into the plate mounting hole 12 of the metal fitting plate 11 for positioning and expansion. Punch 3
3 and the die 62 of the die plate 24, the at least the belt engaging side edge of the belt insertion hole 14 is further expanded (compressed) while being further pressed and deformed toward one surface (lower surface) of the plate.

At this time, the expanding punch 33 and the die 62 are configured as shown in FIG. 8, and the expanding punch 33 is formed such that a part of the circumferential direction of the punch is tapered in the axial direction. The belt is pressed and deformed (compressed and bent) so that at least the belt engaging side edge of the belt insertion hole 14 is pushed open with the movement. That is, the belt engaging side edge of the belt insertion hole 14 is further expanded and deformed to be pressed and deformed toward the one surface (lower surface) side of the plate with the downward movement of the expanding punch 33, thereby shearing the belt insertion hole 14 on the belt engagement side. Opening punch 3 with broken surface
3 is deformed so as to fit into the clearance groove 63 of the die 62 while being smoothly pressed and formed by the tapered surface.

After the belt insertion hole 14 in the metal plate 11 of the strip-shaped steel plate is pressed and expanded by the expanding punch 33 and the die 62, the upper die 22 is moved upward as shown in FIG. 33 and pilot 35 through belt insertion hole 1
4 and pulled out from the plate mounting hole 12. At this time, the belt insertion hole 14 is formed in the subsequent metal plate 11 portion of the strip-shaped steel plate 25 by using the working punch 32 and the die of the die plate 24, and further, the metal plate 11 is formed.
The plate mounting hole 12 is punched in the portion by the punch 31 and the die of the die plate 24, and the strip-shaped steel plate 25 is continuously formed.

On the other hand, after the belt insertion hole 14 is formed by expanding and bending the metal plate 11 with the expanding punch 33, the belt-shaped steel plate 25 is fed again. The strip steel plate 25 is, for example, 2
When the belt is fed by the pitch, the metal plate 11 of the strip-shaped steel plate 25 is guided by the forming punch 50 and the die 51 shown in FIG. When the upper die 22 is moved down by the required stroke at the position shown in FIG. 9, the metal of the metal plate 11 is bulged up on the belt engaging side edge of the belt insertion hole 14 on both sides of the plate. The arc-shaped bulges 15a and 15b are formed in the ridge.

At this time, the belt connecting metal fitting punch 50 and the die 51 have arc-shaped concave curved forming surfaces 64 and 65 facing each other on the belt engaging side of the belt insertion hole 14. The downward movement guides the die hole 66 of the die 51 to the forming punch 50, and the forming punch 50 and the die 51 smoothly bulge out on both sides of the belt engaging side edge of the belt insertion hole 14 in a well-balanced manner. 16 is molded.

At this time, the forming punch 50 is attached to the belt insertion hole 1.
4 is pressed from one surface (lower surface) side of the plate, and the belt engaging side edge of the belt insertion hole 14 is pushed back while being rolled into the concave curved forming surface 64 of the forming punch 50 (see FIG. 4). Bulge to the (top) side. The bulge on the other side of the plate is guided and formed on the arcuate concave curved forming surface 65 of the die.

When the belt insertion hole 14 of the metal plate 11 is formed by the forming punch 50 and the forming die 51, at least the edge portion of the belt insertion hole 14 at the edge of the belt engaging side is moved from the center to the both sides of the plate. The belt is formed so as to be swollen and displaced so as to be caught in the belt, and the bulging portion forming side edge portion of the belt insertion hole 14 is formed into a substantially circular smooth curved sectional structure.
Accordingly, the radius of curvature of the belt engaging side edge of the belt insertion hole 14 can be increased without increasing the thickness of the metal plate 11, while the belt engaging side edge of the belt insertion hole 14 can be increased. Since bulging does not occur in the bulging curved portion 16 of the portion, post-processing such as deburring work of this portion becomes unnecessary.

The bulging portions 15a, 15a are formed in the belt insertion holes 14 of the metal fitting plate 11 by the forming punch 50 and the dies 51.
After the b is formed on both sides of the plate, the belt-shaped steel plate 25 is again fed forward and guided by a work forming punch and a die (not shown). Here, the belt-shaped steel plate 25 is cut to form each metal plate 11 and cut. Metal plate 1
1 is bent to a required angle, and a desired belt connecting metal fitting 10
Is manufactured.

Since the belt insertion hole 14 of the manufactured belt connecting metal fitting 10 has a substantially circular cross-section with a large radius of curvature due to the belt-engaging side edge bulging out on both sides of the plate, the belt insertion hole 14 is formed. The resin coating for applying a vinyl chloride resin or the like around the belt insertion hole 14 of the connection fitting 10 is not required, and the cutting and breaking of the seat belt 13 can be effectively prevented without applying the resin coating.

In the embodiment of the present invention, an example is shown in which a belt connecting metal fitting is continuously punched and formed from a strip-shaped steel sheet by using a press machine. However, individual metal fitting plates are individually formed by a pressing device. It may be processed. Further, it is preferable that the press machine is suitable for mass production so that a plurality of rows of strip-shaped steel sheets can be simultaneously and sequentially press-formed.

Further, in one embodiment of the present invention, an example was described in which the belt connecting metal was used as the anchor metal. However, the belt connecting metal is not limited to the anchor metal, but the through anchor metal and the buckle metal for the safety belt. It may be applied to a tongue plate for a buckle. In the case of a buckle fitting or tongue plate, a processing guide hole is formed instead of the plate mounting hole.

[0048]

As described above, in the belt connecting fitting according to the present invention, the belt insertion hole of the fitting plate is formed by punching with at least an over clearance at the belt engaging side edge. The belt insertion hole of the metal plate is formed by pressing and expanding at least the belt-engaging side edge portion with an expanding punch and a die, and then forming with a forming punch and a forming die to bulge on both sides of the metal plate. Is formed, and the bulging portion forming side edge of the belt insertion hole is formed into a substantially circular curved cross-sectional structure that swells to both sides of the plate, so that the radius of curvature of the belt engaging side edge of the belt insertion hole is increased. And can make smooth surface contact with a large contact area with the seat belt, effectively and reliably prevent the belt from being cut or broken, and form a belt insertion hole The metal plate can be formed into a substantially circular curved cross-sectional structure by pressing and deforming at least the bulging portion that bulges to both sides of the plate at the belt engaging side edge by press molding, so that post-processing such as deburring can be performed. Unnecessary
Processing costs can be reduced.

The belt insertion hole of the metal plate forms a bulge at least on both sides of the plate at the edge of the belt engaging side,
The belt engaging side edge of the belt insertion hole has a substantially circular cross-sectional structure using the bulging portion that protrudes in a well-balanced manner on both sides of the plate, so the resin coating that eliminates the inner edge corner of the belt insertion hole is used. Becomes unnecessary, and the metal fitting for belt connection can be manufactured at low cost.

According to a second aspect of the present invention, there is provided a method for manufacturing a belt connecting metal fitting, wherein at least a part of a punch and a die are provided with overclearance, a metal fitting plate is punched out, and a belt insertion hole is formed. While expanding the shear rupture surface on the over clearance side of the belt insertion hole with the expanding punch, it is pressed and deformed to one side of the plate,
Pressing the forming punch from one side of the plate and rolling it back while rolling in the deformed side edge of the belt insertion hole, swelling to the other side of the plate, and forming the swelling part with the concave curved forming surface facing the forming punch and the forming die. Molded on both sides of the plate, and the bulging portion forming side edge was the belt engaging side of the belt insertion hole, so that the belt engaging side edge of the belt insertion hole became a bulging portion projecting to both sides, and the belt insertion The radius of curvature of the belt engaging side edge portion of the hole can be made large, and the surface can be brought into smooth contact with the seat belt with a large contact area, so that cutting and breaking of the seat belt can be effectively and reliably prevented.

Further, in the method for manufacturing a belt connecting metal fitting according to the third aspect, the belt insertion hole of the metal plate is formed such that at least the wall of the belt engaging side edge of the forming punch and the forming die is from the center to the both sides of the plate. Since burrs are formed so as to be rolled up, burrs are not generated at least at the belt engaging side edge of the belt insertion hole, and post-processing such as deburring is not required, which is economical.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a belt connection fitting according to the present invention.

FIG. 2A is a cross-sectional view showing a developed state of a belt-connecting metal member before bending, and FIG. 2B is a cross-sectional view showing a state of the belt-connecting metal member after bending.

FIG. 3 is a cross-sectional view showing a main part of a belt connection fitting according to the present invention.

FIG. 4 is a diagram showing another embodiment of the belt connecting bracket according to the present invention.

FIG. 5 is a cross-sectional view showing a state after bending of the belt connecting bracket shown in FIG. 4;

FIG. 6 is a schematic cross-sectional view of a press machine that manufactures a belt connection fitting according to the present invention.

FIG. 7 is a cross-sectional view illustrating a manufacturing process of the belt connecting bracket according to the present invention and illustrating a punching process using a processing punch and a die.

FIG. 8 is a cross-sectional view showing a forming process using an expanding punch and a die.

FIG. 9 is a sectional view showing a forming process using a forming punch and a die.

[Explanation of symbols]

 10, 10A Belt connection metal fitting 11 Metal fitting plate 12 Plate mounting hole 13 Seat belt (webbing) 14 Belt insertion hole 15a, 15b Swelling portion 16 Curved portion 20 Press machine 21 Lower die 22 Upper die 23 Die set 24 Die plate 27 Punch Fixing plate 28 Spring 29 Stripper plate 31 Punch punch 32 Processing punch 33 Expanding punch 34,35 Pilot 37,38,39 Punch guide hole 40,41 Pilot guide hole 43,44,45 Dice hole 46,47 Pilot guide hole 50 Molding Punch 51 Molding die 52 Spring 53 Movable table 54 Fixed table 55 Pilot 60,62 Dice 61,63 Escape groove 64,65 Concave curved molding surface

Claims (3)

(57) [Claims] 1. A belt connecting metal fitting, wherein a plate mounting hole and a belt insertion hole are formed in a metal plate, and a seat belt can be attached to the belt insertion hole. While being punched and formed with over clearance on the side edge,
At least the belt-engaging side edge of the stamped and formed metal plate is pressed and expanded by the expanding punch and the die at the belt engaging side edge, and then formed by the forming punch and the forming die to swell on both sides of the metal plate. A belt connecting metal member having a substantially circular curved cross-sectional structure in which a bulging portion is formed, and a bulging portion forming side edge of the belt insertion hole bulges to both sides of the plate. 2. A method of manufacturing a belt connecting metal fitting for manufacturing a belt connecting metal fitting by forming a plate mounting hole and a belt insertion hole in a metal fitting plate. And a belt insertion hole with at least a part of the die having an over clearance, and then, while expanding the sheared fracture surface on the over clearance side of the drilled belt insertion hole with an expansion punch, the entire plate. Side, and then press with a forming punch from one side of the plate and push back while rolling in the deformed side edge of the belt insertion hole to swell to the other side of the plate, and the opposite concave shape of the forming punch and the forming die A bulging portion that bulges to both sides of the plate is formed at the edge of the belt insertion hole on the curved forming surface, and the bulging portion forming side edge is formed as the belt engaging side edge of the belt insertion hole. A method for manufacturing a metal fitting for belt connection, wherein 3. When forming a belt insertion hole of a metal plate with a forming punch and a forming die, at least the meat of the belt engaging side edge portion of the belt insertion hole is displaced from the central portion so as to be wound on both sides of the plate. 3. The method according to claim 2, wherein the bulging portion forming side edge of the belt insertion hole is formed into a substantially circular curved cross-sectional structure.