JPS649486B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clinch nut and a crimping device for crimping and attaching a work piece to the clinch nut. More particularly, this invention relates to a sheet metal clinch nut that is easy and economical to manufacture and install. Clinch nuts that have a space for receiving a cylindrical extruded portion extruded from a workpiece and are used to attach the workpiece by caulking are conventionally known. Known clinch nuts are made from bar stock and are difficult to handle and process, as well as requiring costly manufacturing processes such as boring, counterboring, and tapping. Additionally, conventional clinch nuts accept the cylindrical extrusion of the work piece and rely on the undercut to retain the work piece. This undercut is difficult to process and is not very reliable since the holding force depends on the cylindrical extrusion that fills the undercut.

The clinch nut of the present invention overcomes the problems and deficiencies of conventional clinch nuts. The clinch nut of this invention has a first part connected at a folded part,
Includes a second arm. Both arms are pressed into the unfolded state from sheet metal, and the openings in each arm can be formed during the above pressing process, or later in a secondary processing process, or even formed in the pressing process and then processed in the secondary processing. It may be corrected during the process. Both arms are then bent into a U shape, and the openings in both arms are aligned axially. The first opening of the first arm is larger than the second opening of the second arm and is adapted to receive the cylindrical extrusion of the work piece. The other second opening is dimensioned to receive the shank of a tapping screw which initially taps into the cylindrical extrusion of the workpiece and then taps into the second opening of the second arm. As the tapping screw is screwed firmly into the clinch nut, the tapping screw draws the second arm toward the first arm due to the elasticity of the folded portion where both arms are connected.
Therefore, a restoring force is generated in the second arm that tends to separate it from the first arm, and this restoring force causes the female thread provided in the second opening to strongly engage with the thread of the tapping screw, causing the tapping screw to close. prevent it from loosening.
Furthermore, while the conventional clinch nut had to be made for each thickness of the work piece, the clinch nut of the present invention can accommodate the cylindrical extrusion part extruded from the work piece in the area between the two arms, so that the clinch nut has a certain range of thickness. Can be used for workpieces of medium thickness.

The clinch nut of the present invention provides improved workpiece retention, is easier and cheaper to manufacture, and has tightening characteristics not available with conventional clinch nuts.

Hereinafter, the present invention will be explained with reference to the accompanying drawings.

10 shows an embodiment of a clinch nut according to the present invention. 12 and 14 are parallel arms connected by a folded part 15, the upper first arm 12 has a first opening 16, the lower second arm 14 has a second opening 18, and both openings 16 and 18 are concentric. It is. Each aperture has two parts. That is, the first opening 16 is connected to the cylindrical portion 20 and the truncated conical portion 2 that communicates with the cylindrical portion at the small diameter end.
2 on the upper and lower sides, and serrations 24 are provided on both parts as rotation prevention means.

The second opening 18 has a truncated conical portion 28 and a cylindrical portion 26 at the top and bottom. This cylindrical portion 26 is the cylindrical portion 2 of the opening 16.
The inner diameter is smaller than 0. The cylindrical part 20 is a work piece 30
The inner diameter is large to accommodate the cylindrical extrusion 32 from the inside. The inner diameter of the cylindrical portion 26 is smaller than the thread diameter of the tapping screw 34. The screw may be thread forming or thread cutting.

To use the clinch nut of the present invention, the clinch nut 10 is positioned below the workpiece 30. A piercing device (punching device) having approximately the same diameter as the root diameter of the screw 34 is inserted into the first opening 16 through the workpiece 30, and the cylindrical extrusion portion 32 extruded from the workpiece is inserted into the opening 16. Push it in Nats 10
Make it look brighter. Since the cylindrical extrusion part 32 protrudes into the truncated conical part 22, which has an inner diameter larger than that of the cylindrical part 20, the work piece is fixed to the nut so as not to move in the lateral and axial directions. The serrations 24 then engage the outer surface of the cylindrical extrusion 32, and the spaces between the teeth of the serrations are filled with the extrusion to prevent the work piece from rotating relative to the nut.

Depending on the thickness of the workpiece 30 and the spacing between the arms 12 and 14, the cylindrical extrusion 3 is formed by caulking.
2 protrudes into the truncated cone portion 28 of the second opening 18, the serrations 24 may also be provided in the truncated cone portion 28. The tapping screw 34 is then screwed through the cylindrical extrusion 32 and into the cylindrical portion 26. Cylindrical part 2
6 has an inner diameter suitable for receiving this screw.
Screws 34 tighten panel member 35 onto work piece 30. As the screw is tightened into the cylindrical portion 26, the second arm 14 resiliently deflects obliquely toward the first arm 12, securing the screw with the newly formed thread in the clinch nut and preventing loosening of the screw. To prevent.

FIG. 5 shows a continuous unfolded piece of the clinch nut 10 pressed from sheet metal material and connected to the lower second arm by very small connections 36, 38. With such a shape, the openings 16 and 18 can be easily formed by pressing, drilling, shaping, and serration. And both openings 16, 18
When the arm 12 is folded back so that the axes of the two are aligned, it becomes a continuous clinch nut.

Fig. 6 shows a crimping device 40 that automatically feeds a clinch nut and swages a workpiece onto the clinch nut.
shows. The cylindrical outer piston 42 is attached to the frame 44
It is provided so that it can move up and down, and is pushed up by a spring 46.
An inner piston 48 is provided in a hollow portion of the outer piston so as to be movable up and down, and its upper end is connected to a power cylinder 50 such as a pneumatic, hydraulic, or electromagnetic actuator. A piercing device 52 is attached to the lower end of the inner piston. A spring 54 is provided between the movable portion of the power cylinder 50 and the top surface 56 of the outer piston 42.

One end of the linkage 58 is connected to the power cylinder 50, and the other end is connected to the rocker arm 60. A feed pawl 62 is pivotally attached to the rocker arm. Feed claw 6
2 preferably has a plurality of tongues 64 (one of which is shown) which engage the slits between the first arms on the series of clinch nuts connected by the joints 36, 38. The continuum is adapted to be advanced beneath the outer piston. Since the trailing edge of the tongue piece 64 is tapered, it can be easily removed from the slit between the first arms of the clinch nut during the next return process after being fed. An upwardly spring biased plunger 66 is adjacent the cutting blade 68 to lift the series of clinch nuts from the bed.

The operation of the crimping device for the second embodiment of the clinch nut shown in FIGS. 7 to 9 will be explained. In this clinch nut 110, the first opening 116 in the upper first arm 112 has anti-rotation means therein in the form of teeth 124, the lower half of the teeth 124 being diagonally undercut. The upper half 128 of the second opening 118 in the lower second arm is formed by punching and recessing the arm from the upper surface, and the lower surface of the arm is formed with a recessed material to protrude and form a ring-shaped protrusion. 121, and a hole in the lower half of the second opening 118, which is smaller than the thread diameter of the tapping screw, is opened in this protrusion 121.

When the power cylinder 50 descends due to operation,
Since spring 54 is stronger than 46, outer piston 42
Both the inner piston 48 and the inner piston 48 descend, and the spring 46 is compressed. When the lower end of the outer pinston 42 contacts the upper surface of the work piece 30, the plunger 66
The continuum of the work piece and the clinch nut is pushed down against the upward force of . Once spring 46 is fully compressed and spring 54 begins to compress, piercing device 52 is lowered into work piece 30.

When the downward thrust of the piercing device overcomes the elasticity of the folded portion 115 connecting the upper first arm and the lower second arm, both arms 112 and 114 come into contact (FIG. 8). Of course, this will depend on the material of the klina nuts and the thickness of the material. The formation of the ring 121 described above is also similar. If the force is large enough and both arms come into contact, the second opening 118
Cylindrical extrusion part 3 extruded from the work piece in the upper half of the
2, so that the cylindrical extrusion can be reliably moved into it. However, the ring-shaped protrusion 121 acts as a reinforcing member, ensuring that the upper half 128 of the second opening remains uncollapsed until extrusion is completed. When the upper surface of the work piece 30 is contacted by the lower end of the inner piston 48 or the shoulder 53 of the piercing device, the shoulder 53 performs two functions. The shoulder prevents material from the cylindrical extrusion from attempting to escape upwards while the piercing device 52 remains within the lower half of the second opening and prevents any material from exiting the underside of the clinch nut. block If a further downward force is applied, the shoulder 53 has a second function of flattening the ring-shaped projection 121. As a result, the material forming the ring-shaped protrusion is removed from the opening 1.
18 , the cylindrical extruded portion 32 is pressed upward and caulked into the first opening 116 to fit into the gap between the teeth 124 . (9th
figure).

As the power cylinder 50 moves upward while retracting the piercing device 52, the linkage 58
is pulled from the dotted line state to the solid line state in FIG. 6, and rotates the rocker arm 60 counterclockwise. This causes the tongue 64 on the feed pawl 62 to engage the slit in the clinch nut chain and advance the chain to the right. The feed pawl 62 is set back excessively to the left as shown by the dotted line in FIG. 6, and when the piercing device 52 leaves the work piece 30 upward, it pulls the slit of the clinch nut continuum and advances the continuum. It is necessary to do so.
When the piercing device 52 moves upward from the workpiece, the workpiece crimped to the cut-off leading clinch nut is moved in the horizontal or vertical direction of the crimping device by a device not shown, and the position of the clinch nut on the workpiece is adjusted. can be changed as desired. When the downward force on the piercing device is removed, the second arm 114 springs back into approximation with the first arm similar to second arm 14 of FIG. The amount of springback depends on the material, such as how much the folded portion 115 is deformed. In the embodiment of FIGS. 1 to 4, the tapping screw taps the cylindrical portion 26 of the second opening 18 and does not tap the truncated conical portion 28, but in this second embodiment, the upper half of the second opening 118 is recessed. Since the portion 128 is returned to its original state by pushing in the ring 121, the tapping screw taps approximately the entire length of the second opening 118, so that the screw engagement is large.

Although the present invention has been described above with reference to the illustrated embodiments, the present invention can be implemented with various structural changes within the framework of the technical idea described in the claims at the beginning.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the clinch nut of the present invention, Fig. 2 is a sectional view of Fig. 1, Fig. 3 is a sectional view of a work piece crimped to the clinch nut of Fig. Figure 5 is a cross-sectional view of a panel mounted on a workpiece, Figure 5 is a plan view of a continuously unfolded piece of a punched clinch nut, and Figure 6 is a cross-section of a part of the crimping device that crimps a workpiece to the clinch nut. A schematic side view, FIG. 7 is a cross-sectional view of another embodiment of the clinch nut of the present invention, FIG. 8 is a cross-sectional view of a work piece being swaged into the clinch nut of FIG. 7, and FIG. 9 is the same as above. This is a cross-sectional view of the work piece after caulking.
0,110 is the clinch nut, 12,112 is the first arm, 14,114 is the second arm, 16,1
16 is a first opening, 18, 118 is a second opening, 20
2 is a first portion of the first opening, 22 is a second portion of the first opening, 24 is a serration exemplified as a rotation prevention means, 30 is a work piece, 32 is a cylindrical extrusion portion of the work piece, 34 is a tuft pin screw, 42 is a cylindrical outer piston, 48 is an inner piston, 50 is a power cylinder, 52 is a piercing device, 58 is a linkage,
62 is a feed pawl, 66 is a plunger, 68 is a cutting blade, and 124 is a tooth-like projection illustrated as a rotation prevention means.

Claims (1)

[Claims] 1. A first arm that contacts the work piece on one side;
a second arm extending substantially parallel to the other surface of the first arm and connected to the first arm at a folded portion; a cylindrical extrusion portion provided on the first arm and extruded from the work piece; a first receiving opening, provided in the second arm generally concentrically with the first opening;
At least a portion thereof includes a second opening having a diameter smaller than the thread diameter of a tut pin screw screwed through the cylindrical extrusion, and the first opening includes a first opening having a predetermined inner diameter.
and a second portion having a larger diameter than the first portion and located on a side farther from the surface that contacts the work piece, and means for preventing rotation between the cylindrical extrusion portion of the work piece and the first arm. A clinch nut that is characterized by having an inner periphery. 2. A clinch nut according to claim 1, in which the tapping screw in the region of the first arm screws only into a cylindrical extrusion of the work piece, and in the second arm into a second opening. 3. When the tapping screw is tightened into the opening of the second arm, the second arm is bent toward the first arm, and the folded portion connecting both arms serves as means for preventing the screw from loosening and coming out. Clinch nuts as described in section. 4. The clinch nut according to claim 1, wherein the rotation prevention means is a plurality of serrations provided on the inner periphery of the first opening. 5. The clinch nut according to claim 1, wherein the rotation prevention means is a plurality of tooth-like protrusions provided on the inner periphery of the first opening. 6. The clinch nut according to claim 1, wherein a surface of the second arm that does not face the first arm has a ring-shaped protrusion surrounding the second opening. 7. A crimping device for crimping and fixing a workpiece to a clinch nut according to claim 1, which comprises a cylindrical outer piston provided movably in the vertical direction, and a cylindrical outer piston provided vertically movably in a hollow portion of the outer piston. an inner piston that is movable in a direction; and a power cylinder that connects the inner piston to move the piston up and down, and when the piston is moved downward, the lower end of the inner piston projects downward from the lower end of the outer piston. , the inner piston has a piercing device at its lower end, a linkage connects the power cylinder and a feed pawl that advances the clinch nut, and a plunger biased upward by a spring is generally opposed to the outer piston. 1. A caulking device for caulking a work piece to a clinch nut, characterized in that a cutting device is provided adjacent to the plunger to separate the clinch nut from a continuous body of the clinch nut.