JP3138624B2 - Manufacturing method of belt connection metal fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a metal fitting for connecting a belt, such as a safety belt, and more particularly to a method of manufacturing a metal fitting for connecting a belt, such as a safety belt, in which cutting and breaking of the belt are effectively prevented.

[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] Similar belt connecting metal fittings are disclosed in Japanese Utility Model Registration No. 30000223 and Japanese Utility Model Registration No. 30000224.
This is also disclosed in the official gazette.

[0009]

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-mentioned 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 method of manufacturing a metal fitting for belt connection, which can be reliably and reliably prevented.

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 at the belt engaging side edge of the belt insertion hole of the metal plate is unnecessary. It is an object of the present invention to provide a method for manufacturing a connection fitting.

Still another object of the present invention is to stably perform resin coating around a belt insertion hole of a metal plate, while effectively breaking or cutting a seat belt even if the resin coating breaks. Another object of the present invention is to provide a method of manufacturing an inexpensive metal fitting for belt connection that can be prevented.

[0013]

SUMMARY OF THE INVENTION A method of manufacturing a belt connecting bracket according to the present invention has the following objects.
As set forth in claim 1, in a method for manufacturing a belt connecting metal fitting for manufacturing a belt connecting metal fitting by forming at least a belt insertion hole in a metal fitting plate, processing is performed when the belt inserting hole is formed in the metal fitting plate. At least a part of the punch and the die are provided with over clearance to form a belt insertion hole, and then, while expanding the sheared fracture surface on the over clearance side of the formed belt insertion hole with an expanding punch, the plate is opened. It is pressed and deformed to one side, and then pressed with a forming punch from one side of the plate and pushed back while wrapping around the deformed side edge of the belt insertion hole to swell to the other side of the plate, and the opposite recesses of the forming punch and forming die Extruded on both sides of the plate except for the belt non-engagement side edge facing the belt engagement side edge on the belt engagement side edge of the belt insertion hole on the curved surface Forming a bulging portion, and forming the bulging portion forming side edge portion as the belt engaging side edge portion of the belt insertion hole, and then molding at least the belt engaging side of the metal plate with a resin molding material. It is a method of forming and covering at least the vicinity of the belt insertion hole except for the seat belt insertion hole, and covering the bulging portion at the edge of the seat belt insertion hole.

According to a second aspect of the present invention, there is provided a method for manufacturing a belt connection metal fitting, wherein the belt insertion hole of the metal plate is formed by a forming punch and a forming die. At the time of processing, the thickness of the belt engaging side edge portion of the belt insertion hole is rolled from the center portion to both sides of the plate except for the belt non-engaging side edge portion facing the belt engaging side edge portion. This is a method in which the bulging portion forming side edge of the belt insertion hole is formed into a substantially circular curved cross-sectional structure by displacing.

[0015]

In the method for manufacturing a belt connection metal fitting according to the first aspect, at least a part of a punch and a die are provided with an overclearance, a metal plate is punched out, a belt insertion hole is formed, and the formed belt is formed. While expanding the sheared fracture surface on the over clearance side of the insertion hole with the expanding punch, it is pressed and deformed to the one surface side of the plate, and then pressing the forming punch from the one surface side of the plate and rolling the deformed side edge of the belt insertion hole It is pushed back and swells to the other side of the plate, and the concave punching surface of the forming punch and the forming die is engaged with the belt engaging side edge of the belt insertion hole, and the belt is not engaged with the belt engaging side edge. Except for the mating side edge, the bulging portion is formed on both sides of the plate, and the bulging portion forming side edge is set as the belt engaging side of the belt insertion hole, and at least the belt insertion hole of the metal fitting plate is formed. Since the resin was molded and covered with resin molding, the belt engaging side edge of the belt insertion hole became a bulging portion that protruded to both sides, and this bulging portion was further thickened by resin molding. The radius of curvature of the belt engaging side edge of the belt through hole can be further increased, and a smooth contact can be made with a large contact area with the seat belt, thereby effectively cutting and breaking the seat belt. Can be prevented.

Further, in the method for manufacturing a belt connection metal fitting according to claim 2, the belt insertion hole of the metal plate is formed as follows.
Forming process so that the wall of the belt engaging side edge is rolled up from the center to both sides of the plate from the center except for the belt non-engaging side edge facing the belt engaging side edge with the forming punch and the forming die. Therefore, no burrs are generated at least at the belt engaging side edge portion of the belt insertion hole, and post-processing such as deburring becomes unnecessary, which is economical.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for manufacturing a belt connecting bracket according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an example in which a belt connecting fitting manufactured by the manufacturing method according to the present invention is applied to a seat belt device fixed to a vehicle body of an automobile.

In the seat belt device 1, as shown in FIG. 1, one end of a seat belt 2 as a webbing is attached to an anchor fitting 5 as a mini-anchor attached to a floor of a vehicle body 3 or a lower end of a center pillar 4. Locked. The other end of the seat belt 2 is sequentially connected to a winding device 8 as a seat belt retractor via a tongue plate 6 and a through anchor 7 as a guide anchor, and the seat belt 2 is biased by the spring force of the winding device 8. Is wound up to the storage side. The through anchor 7 is pivotally supported by a bolt on a center pillar 4 or a shoulder adjuster device (not shown) as an elevating device attached to the center pillar 4.

The tongue plate 6 is detachably engaged with a buckle device 9 provided on the side of the seat substantially at the center of the vehicle body. In this engaged state, the seat belt 2 is provided so as to be slidable in the longitudinal direction. The belt 2 can be freely pulled out and stored.

FIG. 2 shows an example in which the belt connecting fitting is used as the tongue plate 6 of the seat belt device 1.

The tongue plate 6 has a metal plate 11 made of carbon steel such as S55CM. The metal plate 11 is formed, for example, by stamping and forming a 2.3 mm-thick strip-shaped steel plate into a substantially T-shape. The metal plate 11 has an operation side base 11a for performing a plate operation and a tongue portion 11b which is attached to and detached from the buckle device 9, while the metal plate 11 has a tongue locking hole 12 for locking the tongue portion 11b to the buckle device 9. A belt insertion hole 14 that forms a seat belt through hole 13 through which the seat belt 2 can be inserted is provided. After the metal plate 11 has the tongue locking hole 12 and the belt insertion hole 14, the seat belt engaging side is
Molded with a resin molding material 19 such as nylon or polyester, and at least the vicinity of the belt insertion hole 14 is coated as shown in FIG.

As shown in FIGS. 4 and 5, the belt insertion hole 14 formed in the metal plate 11 is formed in a long hole shape extending in the plate width direction. The bulging portions 15a and 15b which bulge in a well-balanced manner are formed on both sides, and the cross-sectional shape of the edge portion on the belt engaging side is configured to be a substantially circular smooth curved cross-sectional structure.

As shown in detail in FIG. 6, the belt insertion hole 14 of the metal fitting plate 11 is formed such that the thickness of the belt engaging side edge is raised on both sides of the plate, and the belt engaging side edge is balanced on both sides of the plate. Bulging parts 15a, 15b that protrude well
Each of the bulging portions 15a and 15b is used to form the belt engaging side of the belt insertion hole 14 into a curved cross-sectional structure having a smooth curved portion 16 having a substantially circular cross section. As shown in detail in FIGS. 4 to 6, no bulging portion is formed on the belt engaging side edge of the belt insertion hole 14 facing the belt engaging side edge. Thereby, the curvature radius R of the substantially circular curved surface of the belt engaging side edge of the belt insertion hole 14 is obtained.
Can be increased, and even if the thickness (plate thickness) of the metal plate 11 is not increased, it is equivalent to an increase in the thickness of the plate. For example, the thickness of the metal plate 11 is set to 2.
When the length is 3 mm, the size (diameter) of the bulging portions 15a and 15b can be set to 2.5 mm or more, for example, 2.6 mm.

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 on the belt engaging side edge (or the entire circumference), and these bulging portions 15a, 15b are used to form a belt engaging side. A curved portion 16 having a substantially circular cross section is 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 that formed by protruding a rib smoothly connected to the inner edge of the belt insertion hole on both sides of the plate of the belt insertion hole 14. The rigidity of the metal plate 11 can be increased, and the mechanical and physical strength can be improved. Reference numeral 17 denotes a space for engraving, and reference numeral 18 denotes a space for a lot number.

Next, a method of manufacturing a device for manufacturing the tongue plate 6 as a belt connecting bracket will be described.

The device for manufacturing the tongue plate 6 as the belt connecting metal fitting is constituted by a punching type continuous press machine 20 shown in FIG. This press machine 20 has a die set 2 composed of a fixed lower mold 21 and a movable upper mold 22.
The die plate 24 is fixed on the lower die 21 of the die set 23, and the strip-shaped steel plate 25 to be formed is mounted on the die plate 24. The belt-shaped steel plate 25 is formed by forming a steel plate of carbon steel or the like, and is formed in a belt shape so that a number of metal plates 11 are continuously arranged in a row at a predetermined pitch 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 the ascending and descending movement of the movable base 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
A process of cutting the strip-shaped steel plate 25 into individual metal plates 11 on the downstream side of the die 0 and the dies 51, and is not necessary in the case of the metal plate 11 for the tongue plate. A forming punch and a die (both not shown) are provided.

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

The strip-shaped steel plate 25 in which the tongue locking holes 12 are formed in the metal plate 11 is sequentially fed by one pitch P corresponding to one metal plate 11. The upper die 22 moves down by a required stroke while the strip-shaped steel plate 25 is fed by a predetermined pitch, and the pilot 34 is inserted into the drilled tongue locking hole 12 to position the bracket plate 11 and The metal plate 11 is punched by the working punch 32 and the die 60 of the die plate 24, and the belt insertion hole 14 is formed in the plate operating base 11a. At this time, the tongue locking hole 12 is punched and formed simultaneously with the punch 31 and the die of the die plate 24 in the subsequent metal plate 11.

Working punch 3 formed on press machine 20
8 and the die 60 on the die plate 24 are configured as shown in FIG. 8. The clearance δ between the working 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 the over clearance δ1. The overclearance δ1 has a gap of 10% to 30%, preferably about 15% to 20%, with respect to a plate thickness (sheet thickness: for example, 2.3 mm) of a strip-shaped steel plate as a processing material, and a belt insertion hole. The remaining part of 14 has an appropriate clearance δ2, for example, a plate thickness ratio of 5% to 10%, preferably 5% to 6%.
It is formed in the gap of the degree.

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.
Pull out the belt insertion hole 14 and the tongue locking hole 12 of one part. After this drawing, the strip-shaped steel plate 25 is sequentially fed by one pitch, and the upper die 22 is again moved down by a required stroke to move the pilot 35 to the tongue locking hole 12 of the metal plate 11.
To the belt insertion hole 1 by the expanding punch 33 and the die 62 of the die plate 24.
4, while at least the belt engaging side edge is expanded (compressed), the plate is 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. 9, and at least a part of the expanding punch 33 in the circumferential direction of the punch is tapered in the axial direction.
Pressing deformation (compression bending) is performed so that at least the belt engaging side edge of the belt insertion hole 14 is pushed open with the downward movement of the expanding punch 33. 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. The fracture surface is deformed so as to fit in the clearance groove 63 of the die 62 while being smoothly pressed and expanded by the tapered surface of the expanding punch 33.

After the belt insertion hole 14 of 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 tongue locking hole 12. At this time, the belt insertion hole 1 is formed in the metal plate 11 subsequent to the belt-shaped steel plate 25.
4 is formed simultaneously with the working punch 32 and the die of the die plate 24, and further, the tongue locking hole 12 is punched in the subsequent metal plate 11 by the punch 31 and the die of the die plate 24.
5 is continuously formed.

On the other hand, after the belt insertion hole 14 is formed in the metal plate 11 by the expanding punch 33, the belt-shaped steel plate 25 is fed again. When the belt-shaped steel plate 25 is fed forward by, for example, two pitches corresponding to two metal plate 11, the metal plate 11 of the belt-shaped steel plate 25 is moved forward as shown in FIG.
Are guided by a forming punch 50 and a die 51 shown in FIG. FIG.
By lowering the upper die 22 by the required stroke at the processing position shown in FIG.
4 is bulged on both sides of the plate, and the arc-shaped bulges 15a,
15b is formed.

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 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), where the belt-shaped steel plate 25 is cut to form individual metal plates 11. The cut metal plate 11 is subjected to heat treatment such as quenching and tempering after being surface-treated by plating or the like, and then resin molding is performed on a required portion of the metal plate 11, and a desired tongue plate 6 is connected to the belt connection. Manufactured as metal fittings.

The resin molding of the metal plate 11 is performed by inserting a tongue locking hole 1 into a mold splitting mold (not shown).
Positioning is set accurately using the tongue formed with 2. Subsequently, the heat-softened resin molding material or liquid resin material is pushed into a split mold in which the metal plate 11 is set, and is cured in the split mold to form a tongue plate 6 having a desired shape.

The tongue plate 6 is shown in FIGS.
, The seat belt 2 excluding the tongue portion 11a
The engagement side is covered by resin molding. that time,
The belt insertion hole 14 of the tongue plate 6 is filled up by resin molding and is covered except for the seat belt through hole 13 to guide the seat belt 2 to slide smoothly, thereby improving slidability. Let me. For this reason,
The seat belt through hole 13 covers the bulging portions 15a and 15b protruding from both sides of the plate of the belt insertion hole 14, and is formed to be thickened and formed into a smoothly curved shape. The engaging side is formed into a curved shape having a large radius of curvature, and is in surface contact with the seat belt 2 passed through the seat belt through hole 13 while being maintained at a large radius of curvature. The seat belt 2 maintains a large contact area with the seat belt through hole 13 and engages in smooth surface contact, thereby ensuring the slidability of the seat belt 2 and effectively preventing the seat belt 2 from being cut or damaged. And the durability of the seat belt 2 is improved.

Further, even if the resin molding material 19 coated on the tongue plate 6 is damaged or broken by repeating the load action of the seat belt 2 or using the seat belt device 1 for many years, the belt can be inserted. The hole 14 has at least a bulging portion 15 projecting to both sides at the belt engaging side edge.
a, 15b are formed, and the bulging portions 15a, 15b protrude from both sides of the plate in a well-balanced manner so that the belt insertion holes 14
Are formed in a smoothly curved structure having a large radius of curvature. For this reason, breakage and breakage of the seat belt 2 can be effectively and reliably prevented.

In the tank plate 6, an example is shown in which bulging portions 15a, 15b bulging from both sides of the plate are formed at least on the belt engaging side of the belt insertion hole 14. Bulge 15 over
a and 15b may be formed.

FIGS. 11 and 12 show modifications of the tongue plate.

Although the overall shape of the metal plate 11 used for the tongue plate 6A is not substantially different from that shown in FIGS. 4 and 5, when the metal plate 11 is molded with the resin molding material 19, a belt is used. Insertion hole 14
The anti-slip hole 70, which is substantially parallel to the seat belt through hole, is integrally formed of a resin material. The anti-slip hole 70 is formed integrally with the seat belt through-hole 13 by resin molding, and at least one side of the seat belt 2 that has passed through the seat belt through-hole 13 is guided through the anti-slip hole 70 so that the tongue plate 6
A can be relatively held at a required position of the seat belt 2 in a slip prevention state.

FIGS. 13 and 14 show an example in which the metal fitting for belt connection according to the present invention is applied to a through anchor metal fitting.

The through-anchor 7 is formed, for example, by punching and forming a 2.3 mm-thick strip-shaped steel plate, similarly to the tongue plate 6 shown in FIGS.
1, the metal plate 71 is bent along the bending line L at a required angle θ (θ = 20 ° to 40 °), and the plate surface is molded with a resin molding material 72 to provide a required coating. Is done. The metal plate 71 has a plate mounting hole 73 as a bolt insertion hole through which a fixing bolt (not shown) is inserted, and a belt insertion hole 74 through which the seat belt 2 can be inserted. Of these, the belt insertion hole 74
Are coated by resin molding to form seat belt through holes 75 having a long and narrow hole shape through which the seat belt 2 is slidably inserted.

The belt insertion hole 74 formed in the metal plate 71 is formed in a long hole shape extending in the plate width direction as shown in FIGS.
The bulging portions 76a and 76b bulging out of the balance on both sides of the plate are formed at least at the belt engaging side edge, and the cross section of the belt engaging side edge is formed into a substantially circular smooth curved cross-sectional structure. .

As shown in FIG. 16, the belt insertion hole 74 of the metal fitting plate 71 is formed such that the flesh of the belt engaging side edge is raised on both sides of the plate, and the belt inserting hole 74 is tightly spread on the belt engaging side edge on both sides of the plate. Protruding bulging portions 76a and 76b are formed, respectively, and the belt engaging side of the belt insertion hole 74 is formed into a smooth curved cross-sectional structure having a substantially circular cross-section by using these bulging portions 76a and 76b. Thus, the radius of curvature R of the substantially circular curved surface of the belt engaging side edge of the belt insertion hole 74 can be increased, and the thickness of the metal plate 71 can be increased without increasing the thickness (plate thickness). Is equivalent to increasing.

The belt insertion hole 7 of the metal plate 71
The bulging portions 76a and 76b bulging on both surface sides of the plate 4 make the metal plate 71 equivalent to one in which a smooth continuous rib is provided at least on the belt engaging side edge of the belt insertion hole 74. The rigidity of the plate 71 can be increased, and the mechanical and physical strength can be improved.

The production of the metal plate 71 of the through-anchor metal fitting 7 is performed in the same manufacturing procedure as that of the tongue plate 6 by using a punching-type continuous press machine 20 shown in FIG. I do. However, while the shapes and processing pitches of the processing punch and the dies provided in the press machine 20 are different from those of the tongue plate 6, after cutting the strip-shaped steel plate into the individual metal plates 71, the metal plate 71 is bent along the bending line L. Is different from the press machine 20 in that a processing punch and a die for providing a bending at a required angle θ along the axis are provided.

The metal plate 7 is made of a strip-shaped steel plate.
After forming into one, the metal plate 71 is accurately positioned and set on a mold splitting die (not shown) using the periphery of the plate mounting hole 73. Hardware plate 71
After the positioning setting, the molding is performed using the resin molding material 72, and the metal plate 71 excluding the peripheral portion of the plate mounting hole 73 is almost entirely filled. In this case, the resin molding may be performed so as to cover at least the seat belt engaging side of the belt insertion hole 74 of the metal plate 71. The resin molding material covering the bulging portions 76a and 76b of the belt insertion hole 74 of the metal plate 71 is formed so that the belt engaging side of the seat belt through hole 75 has a radius of curvature of approximately 6 to 8 mm, and is formed by resin molding. The radius of curvature can be increased by filling.

FIGS. 16 and 17 show an example in which the belt connecting fitting is applied to an anchor fitting as a mini-anchor.

The anchor 5 has a metal plate 81 formed by stamping and forming a strip-shaped steel plate, like the tongue plate 6. For example, 4 mm
A strip-shaped steel plate made of high-temperature steel or the like having a thickness of about 3 mm is used, and a plate mounting hole 82 as a bolt insertion hole for inserting an unillustrated anchor bolt and a belt insertion hole 83 for inserting the seat belt 2 are formed. . After the metal plate 81 has formed the plate mounting hole 82 and the belt insertion hole 83, the metal plate 81 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 extends across the belt insertion hole 83.

The belt insertion hole 83 formed in the metal fitting plate 81 is formed in a long hole shape extending in the width direction of the plate, and at least the belt engagement side edge of the belt insertion hole 83 bulges in a well-balanced manner on both sides of the plate. Outer part 85a,
85b is formed, and the cross-sectional shape of the belt engaging side edge portion is configured to be a substantially circular and smooth curved cross-sectional structure.

As shown in FIG. 17 (A), the belt insertion hole 83 of the metal plate 81 has the belt-engaging side edge portion raised on both sides of the plate, and the belt-engaging side edge portion is formed on both sides of the plate. Swelling portions 85a, 85 projecting in a well-balanced manner
The belt engaging side of the belt insertion hole 83 is formed into a smooth curved cross-sectional structure having a substantially circular cross-section by utilizing these bulging portions 85a and 85b. This allows
The curvature radius R of the substantially circular curved surface of the belt engaging side edge of the belt insertion hole 83 can be increased, and the metal plate 8
Even if the thickness of the sheet No. 1 is not increased (for example, 4 mm in thickness), the thickness of the sheet is equivalent to that of the plate having a large thickness, and is engaged with the seat belt 2 inserted into the belt insertion hole 83 by a smooth surface contact with a large contact area. It is possible to effectively and reliably prevent the breakage and breakage of the seat belt 2,
The durability of the seat belt 2 can be improved.

The belt insertion hole 8 of the metal plate 81
3 has bulging portions 85a, 85b bulging on both sides of the plate at least at the edge of the belt engaging side, and using these bulging portions 85a, 85b, a curved portion having a substantially circular cross section is formed on the belt engaging side. 86 are formed. Since the curved portion 86 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 projecting from the inner edge of the belt insertion hole on both sides of the plate of the belt insertion hole 83. , Increasing the plate rigidity of the metal plate 11,
The mechanical and physical strength can be improved, and the seat belt 2 can be effectively prevented from being worn or cut, and the durability of the seat belt 2 is improved. Note that reference numeral 87 is a space for engraving, and reference numeral 88 is a space for a lot number.

Since the method of manufacturing the metal plate 81 of the anchor metal 5 is not substantially different from that of the metal plate 71 of the through anchor 7, the description will be terminated. In the case of the anchor fitting 5, it is not always necessary to mold with a resin molding material after the forming processing of the fitting plate 81. However, the belt insertion hole 83 on the engagement side of the seat belt 2 is filled with a resin mold to reduce the radius of curvature. It may be even larger.

[0064]

As described above, in the method of manufacturing the metal fitting for belt connection according to the first aspect of the present invention, at least a part of the punch and the die is provided with overclearance, the metal fitting plate is punched out, and the belt is inserted. A hole is drilled, and the shearing cross section on the over clearance side of the drilled belt insertion hole is expanded and deformed by pressing the expanding punch to the entire surface of the plate, and then the forming punch is pressed from the entire surface of the plate. The deformed side edge of the belt insertion hole is pushed back while being rolled up and swelled to the other side of the plate, and the swelled portion is formed on both sides of the plate by the concave curved forming surfaces facing the forming punch and the forming die. The side edge of the part forming side is the belt engaging side of the belt insertion hole, and then at least the seat belt engaging side of the bracket plate is molded with a resin molding material, and at least the bell is formed. Since the vicinity of the insertion hole is covered except for the seat belt insertion hole, and the bulging portion of the edge of the seat belt insertion hole is covered, the belt engaging side edge of the belt insertion hole becomes a bulging portion projecting to both sides, Since the bulging portion is covered with the resin mold and filled, the radius of curvature of the belt engaging side edge portion of the belt insertion hole can be increased, and a smooth contact can be made with the seat belt with a large contact area. In addition, the seat belt can be effectively and reliably prevented from being cut or broken.

Further, in the method for manufacturing a belt connection metal fitting according to claim 2, the belt insertion hole of the metal plate is formed as follows.
With the forming punch and the forming die, the belt engaging side edge portion is processed so as to be rolled from the center portion to both sides of the plate except for the belt non-engaging side edge portion facing the belt engaging side edge portion. Therefore, no burrs are generated at least on the belt engaging side edge of the belt insertion hole, and post-processing such as deburring is unnecessary, which is economical.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example in which a belt connecting fitting manufactured by a manufacturing method according to the present invention is applied to a seat belt device.

FIG. 2 is a plan view showing an embodiment in which a belt connection fitting is applied to a tongue plate.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a plan view showing a metal plate constituting the tongue plate of FIG. 2;

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

FIG. 6 is an enlarged sectional view showing a main part of a metal plate of the tongue plate shown in FIG. 5;

FIG. 7 is a schematic cross-sectional view of a press machine that manufactures a tongue plate as a belt connection fitting according to the present invention.

FIG. 8 is a cross-sectional view showing a process of manufacturing a tongue plate as a belt connecting fitting according to the present invention, showing a punching process using a working punch and a die.

FIG. 9 is a cross-sectional view showing a forming process using an expanding punch and a die.

FIG. 10 is a sectional view showing a forming process using a forming punch and a die.

FIG. 11 is a plan view showing another embodiment in which the metal fitting for belt connection according to the present invention is applied to a tongue plate.

FIG. 12 is a sectional view taken along the line XII-XII in FIG. 11;

FIG. 13 is a plan view showing an example in which the belt connecting fitting according to the present invention is applied to a through anchor fitting.

FIG. 14 is a sectional view taken along the line XIV-XIV in FIG. 13;

FIG. 15 is a plan view showing a metal plate of the through anchor metal shown in FIG. 13;

FIG. 16 is a sectional view taken along the line XVI-XVI in FIG. 15;

FIG. 17 is a plan view showing an embodiment in which the belt connecting fitting is applied to an anchor fitting as a mini-anchor.

FIG. 18A is a cross-sectional view showing an unfolded state of a metal plate of an anchor before bending, and FIG. 18B is a cross-sectional view showing a state of the anchor after bending.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Seat belt device 2 Seat belt (webbing) 3 Body 5 Anchor fittings (mini anchor) 6, 6A tongue plate 7 Through anchor fitting 8 Belt winding device (retractor) 9 Buckle device 11, 71, 81 Fitting plate 12 Tongue locking hole 13, 75 Seat belt through hole 14, 74, 83 Belt insertion hole 15a, 15b, 76a, 76b, 85a, 85b Swelling portion 16 Curved portion 19, 72 Resin molding material (resin mold) 20 Press machine 21 Lower mold 22 Upper Mold 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 Chair holes 46 and 47 pilot guide holes 50 forming punch 51 forming dice 52 spring 53 carriage 54 fixing stand 55 pilot 60, 62 die 61, 63 relief grooves 64, 65 concave curved molding surface

Claims (2)

(57) [Claims] In a method for manufacturing a belt connecting metal fitting, wherein at least a belt insertion hole is formed in a metal fitting plate to manufacture a belt connecting metal fitting, when a belt inserting hole is formed in the metal fitting plate, a processing punch and a die are formed. A belt insertion hole is drilled with at least a part of over-clearance, and then the shearing cross-section of the drilled belt insertion hole on the over-clearance side is expanded with a spreading punch and pressed against one surface of the plate. Deformed, then pressed with a forming punch from one side of the plate, pushed back while rolling in the deformed side edge of the belt insertion hole, and swelled to the other side of the plate, the concave curved forming surface facing the forming punch and the forming die A bulging portion bulging to both sides of the plate except for a non-belt engaging side edge facing the belt engaging side edge is formed at a belt engaging side edge of the belt insertion hole. The bulging portion forming side edge is formed as a belt engaging side edge of the belt insertion hole. Subsequently, at least the belt engaging side of the metal plate is molded with a resin molding material, and at least the belt is formed. A method of manufacturing a metal fitting for a belt, comprising: covering the vicinity of an insertion hole while leaving a seat belt through hole, and covering a bulging portion at an edge of the seat belt insertion hole. 2. When forming a belt insertion hole of a metal plate with a forming punch and a forming die, the thickness of the belt engaging side edge of the belt inserting hole is changed by a belt non-engaging member facing the belt engaging side edge. The belt according to claim 1, wherein the belt is displaced so as to be wound on both sides of the plate from the center except for the joint side edge, and the bulge forming side edge of the belt insertion hole is formed into a substantially circular curved cross-sectional structure. A method of manufacturing a connection fitting.