JP4169960B2 - Nut with claw for electrical connection and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, an antenna or the like having a male screw on a fixing member is fastened and fixed to a mounting member such as a vehicle with a nut, and a claw of the nut bites into the mounting member to ensure electrical connection. The present invention relates to a nut with a connection claw and a method for manufacturing the same.
[0002]
[Prior art]
In an in-vehicle antenna, a fixing member engraved with a male screw is inserted into a hole formed in a mounting member such as a vehicle chassis, and a nut is screwed into the male screw from the inside. Fastened and fixed to the mounting member. Here, one end of the cable core wire is electrically connected to the antenna element of the vehicle-mounted antenna and is appropriately introduced into the vehicle, and the outer conductor of the antenna is appropriately electrically connected to the chassis or the like to be grounded.
[0003]
Therefore, conventionally, a claw is provided on the nut for fastening and fixing the antenna to the mounting member, and the fastening member is tightened and fixed so that the claw bites into the surface of the mounting member and makes an electrical connection. It is configured to be electrically connected to a mounting member such as a chassis through a male screw and a conductive nut sequentially.
[0004]
An example of such a conventional nut will be described with reference to FIGS. FIG. 5 is an external view of an example of a conventional nut, where (a) is a front view and (b) is a bottom view. FIG. 6 is a diagram illustrating a situation where the claw bites into the surface of the mounting member.
[0005]
As shown in FIG. 5, a plurality of protrusion claws 12, 12... Are provided in the circumferential direction on one side surface 10 a that contacts a mounting member 30 such as a vehicle chassis of a conventional nut 10 (three in FIG. 5). Projected. The claw 12 has a triangular or semicircular cross section, and its protruding height h is substantially constant in the circumferential direction.
[0006]
When the claws 12, 12... Come into contact with the surface of the mounting member 30 by tightening the nut 10 as shown in FIG. 6, the claws 12, 12... Bites into the surface of the mounting member 30. Accordingly, the nut 10 is electrically connected to the mounting member 30.
[0007]
[Problems to be solved by the invention]
By the way, it is desirable that the nut 10 be mass-produced at low cost. Therefore, generally, the outer shape is formed by stamping by forging, and the female screw 14 is engraved in the final process. In one step of molding this outer shape, the claws 12, 12... Are also formed, and the edges of the claws 12 in the circumferential direction are distorted and the corners are rounded. Therefore, as shown in FIG. 6, when the nut 10 is tightened and the claw 12 comes into contact with the surface of the mounting member 30, it is difficult to reliably remove the coating film 30 a, and it bites into the surface of the mounting member 30. It was difficult. Furthermore, the claw 12 has a substantially constant projecting height h in the circumferential direction, which is a cause of poor biting into the surface of the mounting member 30. As a result, there is a problem that the electrical connection between the mounting member 30 and the nut 10 is not reliably performed. Moreover, in order to obtain a reliable electrical connection, the nut 10 must be tightened with a large tightening torque.
[0008]
The present invention has been made to improve the problems of the prior art as described above, and can be used for electrical connection that can reliably remove the coating film and can easily bite into the surface of the mounting member. An object of the present invention is to provide a nut with a claw and a method for manufacturing the same.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the nut with an electrical connection claw of the present invention is a nut that is screwed into a male screw and brought into contact with one side of the mounting member and electrically connected to the mounting member, On the one side of the nut, a plurality of claws are provided with a circumferential protrusion, and the protrusion height of the rear half is provided by lowering the protrusion height of the first half in the tightening rotation direction of the nut. Increasing the height, making the angle formed by the front end surface of the latter half part and the latter half part due to the step difference, and the projecting height of the latter part highest on the front end face and lower on the rear side, The front end surface of the second half portion of the claw is configured to cut or bite the surface of the mounting member along with tightening and fixing.
[0010]
In addition, the manufacturing method of the nut with an electrical connection claw of the present invention is the circumferential direction by stamping by stamping on the one side of the nut material that is screwed into the male screw and abuts one side of the mounting member. Protruding multiple ridges, and by the next stamping, the first half of the ridge is crushed in the screw shaft direction in the direction of tightening rotation of the nut to provide a step, and the protruding height is made lower than the latter half The nail is formed with an acute angle formed by the front end surface of the latter half portion and the latter half portion due to the step, and a female screw is engraved in the material in a further step.
[0011]
Then, by stamping by forging, the projecting height of the protrusion is the highest in the center, and by the next stamping, the first half part is crushed from the center where the projecting height is the highest, and the projecting height The nail can be formed by lowering the height.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an external view of an embodiment of a nut with an electrical connection claw of the present invention, (a) is a plan view, (b) is a front view, and (c) is a bottom view. 2A and 2B are diagrams showing nail molding, where FIG. 2A is a view of a ridge before the first half portion is crushed, and FIG. 2B is a final shape of the nail after the first half portion is crushed. FIG. FIG. 3 is a view for explaining that the claw of the nut with an electrical connection claw of the present invention removes the coating film and further bites into the surface of the mounting member. FIG. 4 is a view showing a manufacturing method in which the outer shape of the nut with an electrical connection claw of the present invention is formed by a plurality of steps by forging and an internal thread is engraved in the final step.
[0013]
First, the shape of the nut with an electrical connection claw of the present invention will be described with reference to FIGS. The nut 20 of the present invention is different from the nut 10 shown in FIGS. 5 and 6 only in the shape of the claws 22, 22... Projecting from the one side surface 20a, and the claws 22, 22. The difference in number does not matter.
[0014]
In the present invention, as shown in FIG. 2 (a), six ridges 28, 28... Are projected in the circumferential direction on one side surface 20a that abuts against the mounting member 30 of the nut 20. The cross section of the protrusions 28, 28... Is triangular or semicircular, similar to the claws 12, 12. Moreover, the projecting height of the ridges 28, 28... Is an arc shape with the highest center in the circumferential direction. In order to make the projecting height of the ridges 28, 28... The highest arc shape at the center in the circumferential direction, the forging die is made so that the height of the ridges 28, 28. Needless to say, both ends in the circumferential direction of the ridges 28, 28... May be made higher by using the fact that metal fluidity is worse than the center. Then, in the tightening rotation direction of the nut 20, the front half portions 22a, 22a... Are crushed by the mold 26 in the screw shaft direction from the center of the protrusions 28, 28. A height difference is provided between the rear half portions 22b, 22b. By this crushing, the width of the protrusions 28, 28... Is not so wide and the flow of the metal material is good, and due to the shearing action, the angle formed between the front end face of the latter half portions 22b, 22b. , Formed at an acute angle of approximately 90 degrees. Thus, the claws 22, 22 ... are formed.
[0015]
In the nut with an electrical connection claw of the present invention having such a shape, as shown in FIG. 3, when the claws 22, 22... Abut on the surface of the mounting member 30, the rear half portions 22 b, 22 b. since corners is at an acute angle, the coating film 30a reliably removed, yet similar to the byte for metal cutting, second half 22b, so that the 22b ... projecting height decreases as the highest rear in the front face Thus, since the clearance angle θ is provided, the biting is not hindered like the claws 12 of the conventional nut 10, and a reliable biting is obtained on the surface of the mounting member 30. Therefore, the nut 20 of the present invention is reliably electrically connected to the mounting member 30. According to the experiment, in order for the claws 22, 22. It was sufficient to tighten with a tightening torque of m. On the other hand, in the conventional example shown in FIGS. 5 and 6, in order to obtain a reliable electrical connection, about 2.5 to 4.0 N.V. m tightening torque was required. Also from this point, in the present invention, a stable electrical connection can be obtained with a lower tightening torque.
[0016]
Next, an example of a method for manufacturing the nut with a claw for electrical connection of the present invention having the above-described structure will be described with reference to FIG. The manufacturing method illustrated in FIG. 4 is a method in which an outer shape is first formed by forging and a female screw is engraved in the final process. As a first step, as shown in FIG. 4 (a), a steel material as a cylindrical and conductive metal material having a predetermined volume is prepared, and in the second step, as shown in FIG. It is flattened by crushing from above and below by striking and shallow holes are provided on the top and bottom surfaces. Further, in the third step, as shown in FIG. 4 (c), further flattening is performed by further stamping, the holes on the upper and lower surfaces are enlarged and deepened, and the circumferential protrusions 28, 28. Form. Further, in the fourth step, as shown in FIG. 4 (d), the holes on the upper and lower surfaces are penetrated, and the front half portions 22a, 22a ... of the ridges 28, 28 ... are crushed to complete the claws 22, 22 ... Let In addition, in the fifth step of the final step, the female screw 24 is cut into the penetrated hole, whereby the nut with an electric connection claw of the present invention is completed.
[0017]
Of course, this manufacturing method by forging is convenient for mass production and can be manufactured at a lower cost than the method of manufacturing the outer shape and the nail by cutting or the like.
[0018]
In the above-described embodiment, the claws 22, 22 ... are formed by crushing the front half portions 22a, 22a ... of the protrusions 28, 28 ... protruding in the circumferential direction by forging. first part 22a by press molding in the direction, may be crushed 22a ..., to lower the projected height further first part 22a, 22a ... cutting to a have been latter part 22b, 22b ... and the front end by the step The corner of the surface may be an acute angle. Further, the projecting height of the claws 22, 22... Should be highest at the front end surface of the rear half portions 22b, 22b... Also good. Furthermore, in the above embodiment, it has been described that the outer shape is formed by forging and the female screw 24 is engraved in the final process. However, if the angle formed by the rear half portions 22b, 22b. The nut with an electrical connection claw of the present invention may be formed by any sequence of steps. In the above embodiment, the front half portions 22a, 22a ... and the rear half portions 22b, 22b ... are formed at the center of the ridges 28, 28 ..., but are not limited to the center position, and are biased to one side such as the front side. The front half portions 22a, 22a,... And the rear half portions 22b, 22b,... May be configured such that the front end surfaces of the rear half portions 22b, 22b.
[0019]
【The invention's effect】
As described above, since the nut with the pawl for electrical connection according to the present invention is configured, the following special effects can be obtained.
[0020]
In the nut with an electrical connection nail according to claim 1, since the angle formed by the rear end portion of the nail and the front end surface of the latter half portion due to the step is an acute angle, the paint film on the surface of the mounting member can be easily removed. It is easy to bite into the surface of the mounting member, and the protrusion height of the second half of the claw is the highest on the front end surface and lower on the rear side, so even if the claw bites into the mounting member, the clearance angle is the same as the cutting tool bit There is no hindrance. Therefore, the bite is easy and a reliable electrical connection can be obtained. And, due to the good bite, sufficient electrical connection can be obtained with a tightening torque lower than that of the prior art.
[0021]
Moreover, in the manufacturing method of the nail | claw with an nail | claw for electrical connection of this invention, there exist the following special effects.
[0022]
In the manufacturing method of the nut with an electrical connection claw according to claim 2 , the outer shape is formed by forging, and the front half of the ridge is crushed by stamping to form the rear half and the front end surface of the step. Since the nail is formed with an acute angle and an internal thread is engraved in the subsequent process, it is suitable for mass production and can be manufactured at low cost.
[0023]
In the method of manufacturing a nut with an electrical connection claw according to claim 3, the step of providing a clearance angle in the second half of the claw is also performed by forging, and can be simultaneously performed as part of the outer shape forming step. In addition, the number of processes is not increased, and it can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is an external view of an embodiment of a nut with an electrical connection claw of the present invention, (a) is a plan view, (b) is a front view, and (c) is a bottom view.
FIGS. 2A and 2B are diagrams showing the formation of a nail, FIG. 2A is a view of a ridge before the first half portion is crushed, and FIG. 2B is a final shape of the nail after the first half portion is crushed. FIG.
FIG. 3 is a view for explaining that a claw of a nut with an electrical connection claw of the present invention removes a coating film and further bites into a surface of an attachment member.
FIG. 4 is a view showing a manufacturing method in which an external shape of a nut with a claw for electrical connection according to the present invention is formed by a plurality of steps by forging and a female screw is engraved in the final step.
FIG. 5 is an external view of an example of a conventional nut, (a) is a front view, and (b) is a bottom view.
FIG. 6 is a diagram for explaining a situation where the claw bites into the surface of the mounting member.
[Explanation of symbols]
10, 20 Nut 10a, 20a One side surface 12, 22 Claw 14, 24 Female thread 22a First half 22b Second half 28 Projection 30 Mounting member 30a Paint film

Claims (3)

A nut that is screwed into a male screw and brought into contact with one side of the mounting member to electrically connect to the mounting member. A plurality of claws are provided on the one side of the nut with a circumferential protrusion. The projection height of the first half portion is lowered in the direction of tightening the nut and the step is provided to increase the projection height of the second half portion, and the front end surface of the second half portion and the second half portion due to the step are increased. The angle formed is an acute angle, the projecting height of the rear half is highest on the front end face, and lower on the rear side, and the front end face of the rear half of the claw is fixed to the mounting member when tightened and fixed. A nut with an electrical connection claw characterized in that the surface is cut or bite. A plurality of protrusions are provided in the circumferential direction by stamping by forging on the one side of the nut material that is screwed into the male screw and brought into contact with one side of the mounting member. In the tightening rotation direction, the first half of the ridge is crushed in the screw shaft direction to provide a step, and the protruding height is made lower than the second half , so that the angle formed by the front end surface of the second half and the second half is due to the step. A method of manufacturing a nut with a claw for electrical connection, wherein a claw is formed with an acute angle and a female screw is engraved in the material in a further step. 3. The method of manufacturing a nut with an electrical connection claw according to claim 2 , wherein the protruding height of the protrusion is the highest arc shape in the center by stamping by forging, and the protruding height is determined by the next stamping. A method of manufacturing a nut with a claw for electrical connection, wherein the claw is formed by crushing the first half portion from the center where the height is the highest and lowering the protruding height.

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