Clinching stud bolt

Abstract

To provide a clinching stud bolt which can be improved in quality when fixed to an attachment objective plate material.SOLUTION: A clinching stud bolt comprises: a head part 1; a screw shaft part 2 extended from a seat face of the head part; a whirl-stop part 3 which is formed so as to be bulged toward a lower side from the seat face 11 in a spiral direction; an annular groove part 21 annularly recessed toward the inside of the screw shaft part in a radial direction in a position adjoining the lower side in the spiral direction with respect to the whirl-stop part out of the screw shaft part; and an annular protrusion 22 annularly protruding toward the outside of the screw shaft part in the radial direction in a position adjoining the lower side in the spiral direction with respect to the annular groove part. An attachment objective plate material is constituted so as to be sandwiched between the seat face and the annular protrusion, a recessed part 32 recessed toward an upper side in the spiral direction is formed at the whirl-stop part, and an erecting part 31Ab formed at an external peripheral edge of the whirl-stop part is formed into a tapered shape.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a clinching stud bolt that is fixed to a mounting target plate material in a state of preventing removal and rotation prevention.

Background Art

[0002] Conventionally, a clinching stud bolt (clinching stud) that is fixed in a state of preventing removal and rotation prevention by being press-fitted into a mounting hole of a metal plate material (mounting target plate material) is known (for example, see Patent Document 1). This clinching stud bolt includes a head and a threaded shaft portion extending from the seating surface of the head. When fixing another member to the metal plate material, the threaded shaft portion is inserted into the through-hole of this other member, and the nut is screwed so as to move in the direction opposite to the screwing direction of the threaded shaft portion, and the other member is sandwiched and fixed between the nut and the metal plate material.

[0003] The clinching stud bolt described in Patent Document 1 includes a non-circular rotation prevention portion (rotation prevention protrusion in the document) that bulges from the seating surface toward the lower side in the screwing direction of the threaded shaft portion, an annular groove portion (holding groove in the document) that is recessed annularly toward the inner side in the radial direction of the threaded shaft portion, and an annular protrusion (holding ring in the document) that protrudes annularly at a position adjacent to the lower side in the screwing direction with respect to the annular groove portion. The technique described in Patent Document 1 provides a protruding portion that protrudes on the side facing the head around the mounting hole of the metal plate material, so that when the clinching stud bolt is press-fitted into the metal plate material, the protruding portion is crushed by the rotation prevention protrusion, and a large amount of metal is pushed into the holding groove to increase the pull-out load and idle torque.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the clinching stud bolt described in Patent Document 1 is prone to burrs forming as the metal, which is compressed and flows due to the anti-rotation projection, protrudes radially outward from the mounting hole located on the opposite side of the head, beyond the retaining ring. Furthermore, the metal compressed by the anti-rotation projection flows radially outward from the anti-rotation projection, causing deformation and making the metal plate material prone to warping. As a result, when fixing another component to the metal plate material, problems such as damage to the other component due to burrs, scattering of burrs as foreign matter, and interference of surrounding parts by the warped metal plate material occur, leading to a decrease in product quality.

[0006] Therefore, there is a need for clinching stud bolts that can improve the quality when fixed to the mounting plate material. [Means for solving the problem]

[0007] A clinching stud bolt that is fixed to a plate material to be attached in a state that prevents it from coming loose and prevents it from rotating, comprising: a head; a threaded shaft portion extending from the seating surface of the head; a rotation-preventing portion formed to bulge outward from the seating surface toward the downstream side in the screwing direction; an annular groove portion recessed radially inward from the threaded shaft portion at a position adjacent to the rotation-preventing portion toward the downstream side in the screwing direction of the threaded shaft portion; and an annular projection portion protruding radially outward from the threaded shaft portion at a position adjacent to the annular groove portion toward the downstream side in the screwing direction of the threaded shaft portion, wherein the plate material to be attached is sandwiched between the seating surface and the annular projection portion, and the rotation-preventing portion has a recessed portion recessed toward the upstream side in the screwing direction, and the upright portion formed on the outer peripheral edge of the rotation-preventing portion is a tapered clinching stud bolt.

[0008] Furthermore, it is preferable that the recessed portion is molded in sections so as to surround the screw shaft portion. [Effects of the Invention]

[0009] According to the clinching stud bolt of the present invention, since the upright portion of the anti-rotation part is formed in a tapered shape, the volume of the recessed portion is increased and the height of the anti-rotation part can be set low, making it suitable for thin plates to be attached. [Brief explanation of the drawing]

[0010] [Figure 1] This is a bottom view of a clinching stud bolt. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a front cross-sectional view of the clinching stud bolts before they are pressed into the plate material to be attached. [Figure 4] This is a front cross-sectional view after the clinching stud bolts have been pressed into the plate material to be attached. [Modes for carrying out the invention]

[0011] The following describes an embodiment of the clinching stud bolt according to the present invention, based on the drawings. In this embodiment, a clinching stud bolt that is press-fitted into a metal plate material as the mounting target will be described as an example. However, the invention is not limited to the following embodiment, and various modifications are possible without departing from the gist of the invention.

[0012] As shown in Figures 1 and 2, the clinching stud bolt B comprises a flattened cylindrical head 1 with a pair of rounded edges along the circumferential direction, and a threaded shaft portion 2 extending from the seating surface 11 of the head 1. A male threaded portion 2A is formed on most of the threaded shaft portion 2, and the screwing direction X of the threaded shaft portion 2 coincides with the extension direction of the threaded shaft portion 2. The screwing direction X refers to the direction in which the clinching stud bolt B advances relative to the female thread when the male threaded portion 2A of the threaded shaft portion 2 is screwed into a female thread (not shown). Hereinafter, the tip side of the threaded shaft portion 2 will be referred to as the lower side X1 in the screwing direction, and the base side of the threaded shaft portion 2 (the connection side between the head 1 and the threaded shaft portion 2) will be referred to as the upper side X2 in the screwing direction.

[0013] As shown in Figures 3 and 4, the clinching stud bolt B is fixed to the metal plate T in a state that prevents it from coming loose and from rotating, so that the male threaded portion 2A of the screw shaft portion 2 protrudes from the metal plate T and is exposed to the outside when the jig G is removed. The clinching stud bolt B is made of a metal material such as low carbon steel which has higher rigidity than the metal plate T, and the clinching stud bolt B is pressed into the metal plate T by a hydraulic press P, crushing the metal plate T. As a result, the metal plate T is sandwiched between the seating surface 11 of the head 1 and the annular projection 22 which will be described later.

[0014] As shown in Figures 1 and 2, the seating surface 11 of the head 1 has six anti-rotation portions 3 formed at equal intervals around the screw shaft portion 2, bulging toward the downstream side X1 in the screw direction. The clinching stud bolt B also has an annular groove portion 21 recessed radially inward toward the screw shaft portion 2 and an annular projection portion 22 projecting radially outward toward the screw shaft portion 2. The annular groove portion 21 is located on the screw shaft portion 2 adjacent to the downstream side X1 in the screw direction relative to the anti-rotation portion 3, and the annular projection portion 22 is located on the screw shaft portion 2 adjacent to the downstream side X1 in the screw direction relative to the annular groove portion 21. In other words, the anti-rotation portion 3, the annular groove portion 21 and the annular projection portion 22 are arranged sequentially along the screw direction X.

[0015] The groove width of the annular groove 21 is set according to the shape of the annular projection 22 and the ductility of the metal plate T, and in this embodiment, it is set to be the same as the thickness of the metal plate T. The annular groove 21 and the annular projection 22 are continuous in an R shape, and the annular projection 22 and the male threaded portion 2A are continuous in a tapered shape. In this embodiment, the annular groove 21 has an outer diameter smaller than the outer diameter of the male threaded portion 2A formed on the screw shaft 2, and the annular projection 22 has an outer diameter larger than the outer diameter of the male threaded portion 2A formed on the screw shaft 2. In addition, the diameter of the annular projection 22 in this embodiment is set to be smaller than the diameter of the through hole Ta in the metal plate T.

[0016] As shown in Figure 2, the anti-rotation portion 3 has a recessed portion 32 that is recessed toward the upstream side X2 in the screw direction. Due to this recessed portion 32, a convex portion 31A is formed on the outer edge portion 31 of the anti-rotation portion 3 that protrudes in a direction slightly inclined with respect to the downstream side X1 in the screw direction. As the metal of the metal plate T enters the recessed portion 32 and the annular groove portion 21, the clinching stud bolt B is prevented from coming loose and rotated relative to the metal plate T. The volume of the recessed portion 32 and the annular groove portion 21 that accommodate the metal of the metal plate T is set according to the volume and ductility of the metal plate T that flows as it is compressed and plastically deformed by the convex portion 31A. The recessed portion 32 and the convex portion 31A have an inclined portion 30 with an inclined cross-sectional shape, and this inclined portion 30 is the part that connects the recessed portion 32 and the convex portion 31A. Furthermore, the convex portion 31A has an upright portion 31Ab on the opposite side from the screw shaft portion 2, which is formed in a more steeply sloped shape than the inclined portion 30.

[0017] The recessed portion 32 has an inclined portion 30 that is inclined to become deeper as it approaches the screw shaft portion 2, and a straight portion 32A with a straight cross-section that extends parallel to the inner end of the inclined portion 30 at the same height as the seating surface 11.

[0018] Next, using Figures 3 and 4, the effects of pressing the clinching stud bolt B according to this embodiment into a metal plate T will be explained. The metal plate T is a thin metal plate such as a steel plate, and has a through hole Ta pre-formed in it that is larger than the diameter of the annular projection 22 and smaller than the outer diameter of the anti-rotation portion 3, and is supported by a jig G that can withstand the pressing force of the hydraulic press P.

[0019] As shown in Figure 3, before being pressed into the metal plate T, the clinching stud bolt B has its most protruding end 31Aa of the anti-rotation portion 3 in contact with the periphery of the through hole Ta, and the head 1 is in contact with the hydraulic press P. At this time, the annular projection 22 is housed inside the through hole Ta, and the male thread portion 2A of the screw shaft portion 2 protrudes toward the jig G.

[0020] Next, as shown in Fig. 4, when the head 1 is pressed by the hydraulic press P, the clinching stud bolt B moves downward (the lower side X1 in the screwing direction) while the convex portion 31A of the anti-rotation portion 3 bites into the metal plate material T, and is press-fitted until the seating surface 11 abuts against the metal plate material T. At this time, the metal of the metal plate material T crushed corresponding to the volume of the convex portion 31A smoothly flows radially inward along the inclined portion 30 and is accommodated in the recessed portion 32 and the annular groove portion 21. As a result, the clinching stud bolt B when fixed to the metal plate material T is excellent in overall appearance. Further, since the standing portion 31Ab of the anti-rotation portion 3 of the clinching stud bolt B is formed in an inclined shape, the volume of the recessed portion 32 increases and the height of the anti-rotation portion 3 can be set low, so it is suitable for a thin plate as the mounting target plate material T.

Industrial Applicability

[0021] The present invention can be used for a clinching stud bolt that is fixed to a mounting target plate material in a state of preventing loosening and preventing rotation.

Explanation of Signs

[0022] 1: Head 2: Thread shaft portion 3: Anti-rotation portion 11: Seating surface 21: Annular groove portion 22: Annular protrusion 30: Inclined portion 31: Outer edge portion 31A: Convex portion s 31Ab: Standing portion 32: Recessed portion 32A: Linear portion B: Clinching stud bolt T: Metal plate material (mounting target plate material) X: Screwing direction X1: Lower side in the screwing direction X2: Upper side in the screwing direction

Claims

1. A clinching stud bolt that is fixed to the mounting plate material in a state that prevents it from coming loose and prevents it from rotating, The head and The screw shaft portion extending from the seating surface of the head, A rotation-preventing portion formed to bulge outwards from the seat surface toward the lower side in the screw direction, Of the screw shaft portion, at a position adjacent to the anti-rotation portion on the downstream side in the screwing direction, there is an annular groove portion recessed radially inward toward the screw shaft portion, Of the screw shaft portion, at a position adjacent to the annular groove portion on the downstream side in the screwing direction, there is an annular projection that protrudes radially outward toward the screw shaft portion, Equipped with, A clinching stud bolt characterized in that the mounting plate material is sandwiched between the seating surface and the annular projection, the anti-rotation portion has a recessed portion formed toward the upstream side in the screwing direction, and the upright portion formed on the outer peripheral edge of the anti-rotation portion is tapered in a direction toward the downstream side in the screwing direction in which the recessed portion expands.

2. The clinching stud bolt according to claim 1, characterized in that the recessed portion is divided and molded to surround the screw shaft portion.

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