Stud welding pin pull-out prevention member and stud welding pin assembled thereto

Abstract

To provide an inexpensive stud welding pin pull-out prevention member that can effectively suppress or prevent the welding pin from falling out of the part attached to the covering material, even if the connection between the welding pin and the metal substrate becomes detached due to the fracture of the welding pin or the like. [Solution] The leg portion 14 of the stud welding pin 10 is press-fitted into the hollow portion of the coil spring 20, which is formed by winding an elastic wire into a coil shape, so that it can be held elastically. At the end of the coil spring 20 on the leg portion 14 side, the wire forming the coil spring 20 is pulled out a predetermined length in the radial direction of the coil to form a locking portion 22, and this locking portion 22 prevents the stud welding pin 10 from being pulled out of the covering material.

Description

Technical Field

[0004]

[0001] The present invention relates to a member for preventing extraction of a stud welding pin and a stud welding pin assembled with the same, and particularly to a member for preventing extraction that can be suitably used for a stud welding pin for attaching and fixing a predetermined coating material such as a heat insulating material or a refractory material to a metal base material constituting the inner and outer walls of a building, air conditioning equipment, an outer panel of mechanical equipment, etc., and a stud welding pin assembled with such an extraction preventing member.

Background Art

[0002] Conventionally, in buildings, air conditioning equipment, and mechanical equipment, in order to improve the heat insulation effect and sound insulation effect, metal base materials such as steel frames and iron plates constituting the inner and outer walls of these buildings, air conditioning equipment, outer panels of mechanical equipment, etc. (hereinafter abbreviated as metal bases) are provided with predetermined coating materials such as heat insulating materials, refractory materials, non-combustible materials, and sound absorbing materials made of glass wool, rock wool, etc., and are attached and fixed at a predetermined thickness.

[0003] In addition, as a method of attaching and fixing such coating materials such as heat insulating materials and refractory materials to a metal base, a welding pin having a disk-shaped head made of a conductive material and a rod-shaped leg standing thereon is used. After the coating material is overlapped with the metal base, the leg of the welding pin is inserted through a predetermined position of the coating material from the side opposite to the metal base, and further, by welding, the tip of the leg is welded to the metal base, so that the coating material is fixed to the metal base. This method is widely adopted. Further, in such a welding operation, so-called stud welding, in which an arc is generated between the tip of the leg and the metal base by energizing the welding pin to melt the tip of the leg and the like and weld the tip portion to the metal base, is preferably adopted.

[0004] Furthermore, various shapes of welding pins have been proposed for use in attaching and fixing such covering materials, as shown in, for example, Japanese Patent Publication No. 2540382 (Patent Document 1), Japanese Patent Publication No. 3521390 (Patent Document 2), and Japanese Unexamined Patent Publication No. 10-245904 (Patent Document 3). In addition, as an improved version that can ensure even better joint strength when stud welding these welding pins, Japanese Patent Publication No. 3112900 (Patent Document 4) reveals a stud welding pin having a disc-shaped head and a rod-shaped leg erected thereon, with the tip of the leg being tapered to a concave or pointed shape.

[0005] Incidentally, when certain covering materials such as glass wool, rock wool, or other insulating or fire-resistant materials are fixed to a metal substrate such as an air conditioning duct using stud welding pins, a problem sometimes arises where the stud welding pin breaks and falls out of its mounting location. The causes of this stud welding pin breakage include, for example, metal fatigue caused by vibration, which leads to the breakage of the welded connection, or corrosion of the welded portion with the metal substrate or the welding pin itself due to water or other substances adhering to the stud welding pin body, which leads to breakage. In this way, when the welding pin breaks, the connection between the metal substrate and the welding pin is severed, and the welding pin falls out of the inserted covering material.

[0006] Therefore, the applicant previously proposed in Japanese Patent Publication No. 6393636 (Patent Document 5) an insulating cover for stud welding pins, which has a cylindrical portion through which the legs of the stud welding pin are inserted, a cover body portion arranged to cover the surface of the leg-side of the head of the stud welding pin, and at least one locking portion that protrudes integrally from the side of the cylindrical portion and engages with the covering material when inserted into the covering material to prevent the cylindrical portion from coming out. The applicant clarified that the at least one locking portion protruding from the side of the cylindrical portion of such an insulating cover engages with the covering material, thereby preventing the stud welding pin from coming out of the covering material, in other words, from falling out.

[0007] However, in the case of stud welding pins that can be prevented from being pulled out by assembling such an insulating cover, the insulating cover attached to it must be molded into a special shape using an insulating material such as resin, which incurs considerable costs for manufacturing such an insulating cover. As a result, the overall cost of the stud welding pin with such an insulating cover increases. Furthermore, since the locking part that protrudes integrally from the side of the cylindrical part of the insulating cover does not deform, a certain degree of resistance occurs when inserting the insulating cover-stud welding pin assembly into the covering material, making the insertion process difficult and time-consuming. In addition, due to molding errors in the inner diameter of the cylindrical part of the insulating cover, even when the legs of the stud welding pin are inserted into the cylindrical part of the insulating cover, the insulating cover may not be sufficiently fixed and held in place against the stud welding pin, making them prone to detachment and potentially failing to adequately prevent them from falling out. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 2540382 [Patent Document 2] Patent No. 3521390 [Patent Document 3] Japanese Patent Application Publication No. 10-245904 [Patent Document 4] Patent No. 3112900 [Patent Document 5] Patent No. 6393636 [Overview of the project] [Problems that the invention aims to solve]

[0009] In this context, the present invention has been made against this backdrop, and its problem to be solved is to provide an inexpensive stud welding pin pull-out prevention member that can effectively suppress or prevent the welding pin from falling out of the part attached to the covering material even when the connection between the welding pin and the metal substrate comes undone due to the welding pin breaking or the like in the case of a stud welding pin used to attach and fix a predetermined covering material such as a heat insulating material or a fire-resistant material to a metal substrate that constitutes the interior and exterior walls of a building, air conditioning equipment, and the exterior panels of mechanical equipment, etc. Another problem to be solved is to provide a stud welding pin that can effectively exhibit a pull-out prevention effect of the stud welding pin by assembling such a pull-out prevention member onto the stud welding pin. [Means for solving the problem]

[0010] Furthermore, in order to solve the above-mentioned problems relating to a stud welding pin extraction prevention member, the gist of the present invention is a stud welding pin extraction prevention member that is fixedly attached to a stud welding pin, which has a plate-shaped head and rod-shaped legs erected thereon through which a covering material of a predetermined thickness is inserted, and which is welded to the metal base at the tip of the legs by an electric current, and is composed of a coil spring in which an elastic wire is wound in a coil shape, the legs of the stud welding pin are press-fitted into the hollow part of the coil spring and held elastically, while at the end of the press-fitted coil spring on the tip side of the legs, the wire forming the coil spring is pulled out by a predetermined length in the radial direction of the coil to form a locking part, and the extraction of the stud welding pin can be prevented by locking into the covering material at this locking part.

[0011] Furthermore, in one desirable embodiment of the stud welding pin removal prevention member according to the present invention, the locking portion is formed in such a manner that the wire is drawn out in the direction tangential to the coil of the coil spring.

[0012] Furthermore, in another preferred embodiment of the stud welding pin pull-out prevention member according to the present invention, the coil spring is arranged over a predetermined length from the connection between the head and the leg of the stud welding pin to the tip of the leg.

[0013] Furthermore, in another preferred embodiment of the stud welding pin pull-out prevention member according to the present invention, the coil portion of the coil spring is characterized in that it has a length of at least [9 / (L+30 / L)] of the axial length (L:mm) of the leg portion of the stud welding pin.

[0014] Furthermore, according to yet another preferred embodiment of the stud welding pin removal prevention member according to the present invention, the locking portion is characterized in that it is formed by pulling out the wire for a length greater than or equal to the coil diameter of the coil spring.

[0015] Furthermore, according to yet another preferred embodiment of the stud welding pin pull-out prevention member according to the present invention, the coil spring is characterized in that its coil length is 5 mm or more shorter than the length of the leg portion of the stud welding pin, and it is press-fitted onto the leg portion at a distance of 5 mm or more from the tip of the leg portion.

[0016] In addition, the present invention also includes a stud welding pin that, in order to solve the problems related to the assembly of the stud welding pin described above, has a plate-shaped head and a rod-shaped leg portion erected thereon through which the covering material is inserted, and in order to attach and fix a covering material of a predetermined thickness to a metal base, the leg portion is welded to the metal base at its tip portion by the application of electricity, and the stud welding pin anti-pull-out member described above is assembled to the stud welding pin by press-fitting the leg portion of the stud welding pin into the hollow portion of the coil spring that constitutes the member, thereby elastically fixing and holding it. [Effects of the Invention]

[0017] Thus, in the stud welding pin pull-out prevention member according to the present invention, it is basically made of a normal coil spring, and the elastic wire is pulled out at one end in the direction of the coil axis to form a locking portion. As such, it is a simple structure and does not require any special molding operation, so it is possible to make an inexpensive pull-out prevention member, and by extension the entire stud welding pin assembled thereto, inexpensive. Furthermore, since the locking portion can be elastically deformed when inserted into the covering material, it has the advantage of being easy to insert. In addition, when such a locking portion engages with the covering material such as glass wool or rock wool, the stud welding pin, whose legs are elastically pressed into the pull-out prevention member, can be effectively prevented from easily falling out of the covering material.

[0018] Furthermore, in the case of a stud welding pin with such an anti-pull-out member attached, the legs of the stud welding pin are press-fitted into the hollow coil portion of the coil spring constituting the anti-pull-out member, and are held elastically. As a result, even if the stud welding pin breaks and separates from the welded metal base, the elastic locking portion provided on the anti-pull-out member will lock into the covering material, effectively suppressing or preventing the stud welding pin from falling out. Moreover, even when the stud welding pin is inserted into the covering material during installation, the stud welding pin will not easily fall out of the anti-pull-out member and, consequently, the covering material, thus providing the advantage of improved workability during installation. [Brief explanation of the drawing]

[0019] [Figure 1] This is a perspective view illustrating an example of a stud welding pin with an anti-pull-out member assembled according to the present invention. [Figure 2] Figure 1 is an explanatory diagram showing an anti-pull-out member assembled to a stud welding pin, where (a) is a front view and (b) is a top view. [Figure 3] This is an explanatory drawing showing a form in which the extraction prevention member shown in FIG. 2 is assembled to a stud welding pin. (a) is a front explanatory drawing showing the state before they are assembled, and (b) is a front explanatory drawing showing the state after they are assembled. However, in those drawings, the heads of the stud welding pins are all shown in terms of cross-sectional shape. [Figure 4] This is a schematic explanatory drawing showing a state when a target coating material is fixed to a predetermined metal base by stud welding using a stud welding pin assembled with the extraction prevention member shown in FIG. 1. (a) is a cross-sectional explanatory drawing showing a form in which the tip of the leg portion of the stud welding pin is welded to the metal base, and (b) is a cross-sectional explanatory drawing showing a state in which the dropping of the stud welding pin is prevented when the welding of the leg portion of the stud welding pin to the metal base is broken.

Mode for Carrying Out the Invention

[0020] Hereinafter, in order to clarify the present invention more specifically, typical embodiments of the present invention will be described in detail with reference to the drawings.

[0021] First, in FIG. 1, an example of a stud welding pin assembled with an extraction prevention member according to the present invention is shown in the form of a perspective view. Therein, 10 is a stud welding pin, and a coil spring 20, which is an extraction prevention member, is elastically attached to and held on its leg portion 14.

[0022] [[ID=二十一]]More specifically, as clearly shown in Patent Document 4 (Japanese Patent No. 3112900) pointed out above, the stud welding pin 10 is composed of a round dish-shaped head 12 and an elongated rod-shaped leg portion 14 erected thereon. As will be described later, it is the same as the conventional one in that it is made of a metal material capable of being energized for stud welding.

[0023] On the other hand, the coil spring 20, which is the anti-pull-out member, has a form in which an elastic wire is wound in a coil shape, and the leg portion 14 of the stud welding pin 10 is press-fitted into the hollow portion of the coil, so that the coil spring 20 can be elastically held in place of the stud welding pin 10. Moreover, at one end of the coil spring 20 in the axial direction, the wire constituting it is pulled out by a predetermined length in the radial direction of the coil to form a locking portion 22.

[0024] Furthermore, when inserting the leg portion 14 of the stud welding pin 10 into the hollow portion of the coil spring 20, it is necessary to elastically deform the coil shape and assemble it so that it can elastically hold the leg portion 14 of the stud welding pin 10. For this reason, the coil spring 20 is designed to have an inner diameter smaller than the diameter of the leg portion 14. The axial length of the coil is appropriately selected depending on the degree of elastic holding force on the leg portion 14 of the stud welding pin 10. Generally, the length (M) of the coil portion is set to be at least [9 / (L+30 / L)] of the axial length (L:mm) of the leg portion 14, or in other words, L × [9 / (L+30 / L)] or more, taking into consideration ease of insertion and functionality.

[0025] Furthermore, as the coil portion of the coil spring 20 approaches the tip of the leg portion 14 of the stud welding pin 10, it is more susceptible to the effects of the high temperature during stud welding, and there is a risk of damage to the coil portion. Therefore, it is desirable that such a coil spring 20 generally has a coil length (M: mm) that is 5 mm or more shorter than the length (L: mm) of the leg portion 14 of the stud welding pin 10, and that it is press-fitted and held against the leg portion 14 at a distance of 5 mm or more from the tip of the leg portion 14.

[0026] Furthermore, the length of the locking portion 22 in the coil spring 20 is appropriately selected considering the ease with which the stud welding pin 10 assembled to it can be inserted into the covering material and the performance of preventing the stud welding pin 10 from falling out of the covering material. Generally, however, it is desirable that the locking portion 22 be formed by pulling out the wire constituting the coil spring 20 to a length equal to or greater than the coil diameter of the coil spring 20. The upper limit of this length is appropriately selected considering the ease of handling of the coil spring 20 and stud welding pin 10 assembly and the engagement when inserted into the covering material, but generally, it is set to about 7 times or less the coil diameter, preferably 5 times or less.

[0027] In addition, even in the pulling direction of the locking portion 22, as shown in Figure 2(b), the target locking portion 22 is formed by pulling out the wire material constituting the coil spring 20 in the direction tangential to the coil. However, it is also possible to form the locking portion 22 in a manner in which the wire material is pulled out at a predetermined angle in the direction tangential to the coil, or bent in the direction of the coil diameter.

[0028] Furthermore, since such a coil spring 20, which serves as an anti-pull-out member, can basically be manufactured by using a commercially available metal coil spring and pulling out the wire at the axial end of the coil to the side of the coil to form a locking portion 22, it can be provided easily and inexpensively, thereby offering the advantage of effectively reducing the manufacturing cost of the anti-pull-out member.

[0029] Furthermore, when assembling the coil spring 20, which serves as an anti-pull-out member, to the stud welding pin 10, for example, as shown in Figure 3(a), the leg portion 14 of the stud welding pin 10 is inserted relative to the end of the coil spring 20 on the side where the locking portion 22 is not provided, into the hollow portion of the coil. By press-fitting the coil while elastically expanding and deforming its shape, the end of the coil spring 20 on the side where the locking portion 22 is not provided reaches the connection portion between the head portion 12 and the leg portion 14 of the stud welding pin 10, as shown in Figure 3(b). In this way, a stud welding pin 10 is formed in which the coil spring 20 is elastically assembled.

[0030] Furthermore, when using a stud welding pin 10 to which a coil spring 20 as an anti-pull-out member according to the present invention is assembled, to fix a predetermined covering material such as glass wool or rock wool to a metal substrate such as an air conditioning duct, as shown in Figure 4(a), the procedure is as follows. Specifically, first, the covering material 32 is layered to cover the surface of the metal base 30, and if necessary, a surface material 34 such as wire mesh or aluminum kraft paper is interposed. Then, the legs 14 of the stud welding pin 10 are inserted so as to penetrate the covering material 32 and surface material 34 until their tips contact the metal base 30. With the tips of the legs 14 in contact with the metal base 30, stud welding is performed using a predetermined stud welding machine to melt the tips of the legs 14 and the contact portion of the metal base 30, forming a joint 36 and fixing the stud welding pin 10 to the metal base 30, thereby enabling the covering material 32 to be attached to the metal base 30.

[0031] Thus, in a state where the leg portion 14 of the stud welding pin 10 is stud-welded to the metal base 30, if the joint 36 between the leg portion 14 and the metal base 30 breaks due to vibration, corrosion, etc., and the connection of the stud welding pin 10 to the metal base 30 is detached, and the stud welding pin 10 attempts to fall out of the inserted covering material 32, the locking portion 22 of the coil spring 20, which is elastically held by the leg portion 14 of the stud welding pin 10, will lock into the covering material 32, as shown in Figure 4(b), thereby effectively preventing the stud welding pin 10 from coming out.

[0032] Although one representative embodiment of the present invention has been described in detail above, it should be understood that this is merely illustrative, and the present invention is not to be interpreted in any way as being limited by such specific descriptions of embodiments.

[0033] For example, with respect to the stud welding pin 10, known shapes and sizes of its head 12 and leg portion 14 can be appropriately adopted, and it goes without saying that it is not limited to the exemplified shapes and sizes.

[0034] Furthermore, even with respect to the coil spring 20 as an anti-pull-out member, the locking portion 22 provided at one end in the direction of the coil axis may be provided in a straight-extending form as exemplified, or in a curved-extending form without any problem. Moreover, while a straight-wound coil shape as exemplified is commonly used, other coil spring shapes can also be used in the same manner as long as they do not deviate from the spirit of this invention.

[0035] Furthermore, although not listed individually, the present invention can be implemented in various forms with modifications, alterations, and improvements based on the knowledge of those skilled in the art, and it goes without saying that such implementations, as long as they do not deviate from the spirit of the present invention, all fall within the scope of the present invention. [Explanation of symbols]

[0036] 10 stud welding pins, 12 heads 14 Leg sections 20 Coil springs 22 Locking part 30 Metal base 32 Covering material 34 Surface material 36 Joint

Claims

1. To attach and fix a covering material of a predetermined thickness to a metal substrate, the device has a plate-shaped head and rod-shaped legs erected thereon through which the covering material is inserted, and is fixedly attached to a stud welding pin, the tip of which is welded to the metal substrate by an electric current, as an anti-pull-out member. A stud welding pin removal prevention member is characterized in that it is made of a coil spring in which an elastic wire is wound in a coil shape, the leg portion of the stud welding pin is press-fitted into the hollow portion of the coil spring so that it can be elastically held, and at the end of the press-fitted coil spring on the leg tip side, the wire forming the coil spring is pulled out by a predetermined length in the radial direction of the coil to form a locking portion, and the stud welding pin can be prevented from being pulled out by being locked to the covering material at this locking portion.

2. The stud welding pin removal prevention member according to claim 1, characterized in that the locking portion is formed in a manner in which the wire material is drawn out in the tangential direction of the coil spring.

3. The stud welding pin pull-out prevention member according to claim 1, characterized in that the coil spring is positioned over a predetermined length from the connection portion between the head and the leg of the stud welding pin to the tip of the leg.

4. The stud welding pin pull-out prevention member according to claim 1, characterized in that the coil portion of the coil spring has a length of at least [9 / (L+30 / L)] of the axial length (L: mm) of the leg portion of the stud welding pin.

5. The stud welding pin removal prevention member according to claim 1, characterized in that the locking portion is formed by pulling out the wire material over a length equal to or greater than the coil diameter of the coil spring.

6. The stud welding pin pull-out prevention member according to any one of claims 1 to 5, characterized in that the coil spring has a coil length that is 5 mm or more shorter than the length of the leg portion of the stud welding pin, and is press-fitted onto the leg portion at a distance of 5 mm or more from the tip of the leg portion.

7. A stud welding pin for attaching and fixing a covering material of a predetermined thickness to a metal substrate, having a plate-shaped head and a rod-shaped leg erected thereon through which the covering material is inserted, wherein the leg is welded to the metal substrate at its tip when an electric current is applied, A stud welding pin characterized in that the stud welding pin pull-out prevention member according to any one of claims 1 to 6 is assembled to the stud welding pin by press-fitting the leg portion of the stud welding pin into the hollow portion of the coil spring that constitutes the member, thereby elastically fixing and holding it in place.

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