JPH04247177A - Metal fitting for connection - Google Patents

Abstract

PURPOSE:To reduce the fatigue of metal liable to concentrate to one point by increasing the size of the engaging parts of a locking piece as large as possible, and to increase the strength by providing ribs. CONSTITUTION:In the direction orthogonal to the axial direction of the first rod-form body 12 to which plain or bending inclination parts 18a and 18b are formed at both ends, the second rod-form body 14a and the third rod-form body 14b extending parallel to each other are provided. The first rib 20a and the second rib 20b extending outward from the second rod-form body 14a and the third rod-form body 14b respectively are formed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fastening fittings, and more particularly to fastening fittings having increased rigidity and strength against tensile forces.

0002

2. Description of the Related Art Conventionally, fastening fittings have been used. Suitable examples include vehicle door locking devices and conveyor chain link ends. The locking device includes a locking pawl provided on the door side and a fastening metal fitting provided on the vehicle body side. The locking pawl consists of a hook-shaped metal member that can be moved in and out of the space defined by the fastening metal fitting by locking operation, while the fastening metal member is a U-shaped metal member fixed to the center pole. It is made of metal parts.

0003

[Problems to be Solved by the Invention] As mentioned above, since this fastening metal fitting is U-shaped, when tightening, the locking pawl only contacts one point on the top of the locking part of the fastening metal fitting. They are merely engaged. Therefore, if the use is continued for a long period of time, metal fatigue will accumulate at the abutting parts of the fastening metal fittings due to the load of the door, etc., and eventually cracks will occur, causing the connection between the locking pawl and the fastening metal fittings to deteriorate. There is a concern that the door may open during driving, especially if a lateral load is applied to the door etc. when the vehicle tries to turn.

The present invention was made in order to solve this type of problem, and the purpose of the present invention is to make the area where the locking piece should be locked to the fastening fitting as large as possible, and to concentrate it in one place. It is an object of the present invention to provide a fastening metal fitting which reduces the metal fatigue that tends to occur and further increases the strength by providing ribs.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a first rod-like body, and a rod-like body extending in parallel with orthogonal to the axial direction of the first rod-like body from near both ends of the first rod-like body. a second rod-shaped body and a third rod-shaped body, and the first rod-shaped body has a first rib extending outward from a connecting portion of the second rod-shaped body and a connecting portion of the third rod-shaped body. and a second rib, and furthermore, the first rod-shaped body, the second rod-shaped body, the third rod-shaped body, and the first rib and the second rib are formed by bending one steel material. Features.

[0006]

[Operation] In the fastening fitting according to the present invention, the second rod-like body and the third rod-like body extend in parallel in a direction perpendicular to the axial direction of the first rod-like body, and the first rod-like body engages the locking piece. I try to receive it. Therefore, compared to a U-shaped structure, stress areas are dispersed and metal fatigue is less likely to occur. Also, place the ribs first.
Since the second rod-like body and the third rod-like body are made to protrude by extending from both ends of the rod-like body, the strength against tensile force is increased.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the fastening fitting according to the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 is a fastening fitting according to this embodiment, and this fastening fitting 10 is a first
It basically consists of a rod-shaped body 12, a second rod-shaped body 14a, and a third rod-shaped body 14b.

The first rod-shaped body 12 extends long in the axial direction, and flat or curved inclined portions 18a and 18b are formed at both ends of the first rod-shaped body 12.

A second rod-like body 14a and a third rod-like body 14b extend parallel to each other from near both ends of the first rod-like body 12. Note that the first rod-shaped body 12 has a first bulge outward from the second rod-shaped body 14a and the third rod-shaped body 14b.
A rib 20a and a second rib 20b are formed.

[0011] This fastening fitting 10 is manufactured as follows. First, a steel material having a circular cross section and a predetermined diameter, such as chromium-molybdenum steel, is cut to a predetermined length using a cutting device (not shown), and then bent into a U-shape using a bending device (not shown). Next, the fastening fitting 10 of this example is formed using the rib extension device 30 shown in FIG. That is, the rib ejecting device 30 is composed of a lower mold 32 and an upper mold 34. The lower mold 32 includes a cylindrical main die 36 and a sub-die 38. The main die 36 is defined along the axial direction with two holes 42a and 42b having a predetermined diameter into which the steel material 40 bent into a U-shape by the bending device is inserted. The sub die 38 is disposed below the main die 36 and is located in the holes 42a and 42b defined in the main die 36.
Protrusions 44a and 44b are provided to be inserted into.

The upper mold 34 has a cylindrical regulating die 46.
and a pressing die 48. A rectangular hole 50 is defined in the regulating die 46, and the horizontal dimension of the hole 50 in the drawing is selected to be longer than the longest distance between the holes 42a and 42b defined in the main die 36. has been done. A pressing die 48 having a lower surface with sloped sides is inserted into the hole 50 so as to be freely displaceable. An actuator (not shown) is connected to the upper part of the pressing die 48.

Therefore, first, the secondary die 38 is replaced with the main die 3.
Steel material 4 bent into a U shape after being positioned below 6
0 second rod-shaped body 14a and third rod-shaped body 14b are inserted into the main die 3.
It is inserted into the holes 42a, 42b of No. 6 and brought into contact with the protrusions 44a, 44b of the sub die 38. At this time, the curved portion of the steel material 40 is inserted into the main die 36 as shown by the broken line in FIG.
It is floating above the top surface.

Next, the regulating die 46 is fixed in contact with the upper surface of the main die 36, and the pressing die 48 is displaced toward the main die 36 under the biasing action of the actuator. Then, when a pressing force is applied to the steel material 40 while bringing the lower surface of the pressing die 48 into contact with the curved portion of the steel material 40, a flat portion is formed in the central portion of the steel material 40,
The both side portions are pushed outward from the holes 42a and 42b of the main die 36 to form the first rib 20a and the second rib 20b.

Then, the upper mold 34 is separated from the lower mold 32 again under the biasing action of the actuator, and the formed fastening metal fitting 10 is taken out.

FIG. 3 shows a vertical cross section of the bent state of the steel material 40 in the fastening fitting 10 formed by the rib extension device 30 in this manner. That is, the composition 52 constituting the first rod-shaped body 12 is applied to the first rib 2 at approximately right angles at the bent portions of the first rod-shaped body 12, the second rod-shaped body 14a, and the third rod-shaped body 14b.
0a, curved toward the second rib 20b side. The composition 52 bends or bends from the second rod-shaped body 14a and the second rod-shaped body 14b as it is directed toward the first rib 20a and the second rib 20b projected by the pressing die 48 of the rib ejecting device 30. However, the first rib 20a, the second
When it reaches the rib 20b, it becomes parallel again,
The composition shape of these first and second ribs 20a, 20b can increase the strength against tensile force.

In forming the fastening fitting 10, a warm forging method or a hot forging method may be used. In particular, the application of the fastening metal fitting of the present invention is not limited to a vehicle door locking device, but also as a fastening metal fitting for connecting the terminal end and the starting end of a chain for transmitting rotational force, for example. Available. In this case, a tightening device may be separately fixed to the free ends of the second rod-shaped body and the third rod-shaped body.

[0018]

[Effects of the Invention] According to the fastening fitting according to the present invention, the following effects can be obtained.

The first rod-like body extends in the axial direction, and a second rod-like body and a third rod-like body extend in parallel from both ends thereof, and the locking piece is held by the first rod-like body. Therefore, stress concentration is not concentrated in one place, and metal fatigue is less likely to occur. Furthermore, the presence of the ribs has the effect of increasing the strength against tensile force.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a fastening fitting according to the present invention.

FIG. 2 is a longitudinal cross-sectional view of a rib extension device for manufacturing a fastening fitting according to the present invention.

FIG. 3 is a longitudinal cross-sectional view of the fastening fitting according to the present invention, and is a schematic longitudinal cross-sectional explanatory view of the composition of the steel material obtained by the rib extraction device.

[Explanation of symbols]

10... Fastening metal fittings 12...first rod-shaped body 14a...Second rod-shaped body 14b...Third rod-shaped body 20a...first rib 20b...Second rib 30...Rib removal device 32...Lower mold 34...Upper mold 36...Main die 38…Secondary dice 42a, 42b...holes 46...Regulation dice 48...pressing die

Claims (1)

[Claims] 1. A first rod-shaped body, a second rod-shaped body and a third rod-shaped body extending in parallel from near both ends of the first rod-shaped body and perpendicular to the axial direction thereof, The first rod-shaped body has a first rib and a second rib that extend outward from the communication portion of the second rod-shaped body and the communication portion of the third rod-shaped body, and furthermore, the first rod-shaped body and the first rib A fastening fitting characterized in that the two rod-like bodies, the third rod-like body, and the first rib and the second rib are formed by bending a single piece of steel.