JPH0571523A - Weld nut and manufacture thereof - Google Patents

Abstract

PURPOSE:To simply and appropriately cover the upper surface of a thread hole with a seal member with the use of a commercially available weld nut. CONSTITUTION:A weld nut is composed of a nut body formed at its proximal end with a welding projection 1, and a seal member 3 made of a metal plate and welded to the upper end surface of the nut body 2. A positioning hole 4 and a slit 5 surrounding the positioning hole 4 are formed in the seal member 3. There is provided a connecting part 9 between a center part 7 and outer peripheral part 8 which are marked off from each other by this slit 5. By bending the seal member 3 at the connecting part 9, the center part 7 is separated from the upper end surface of the nut body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weld nut which is welded and attached to a portion to be attached such as a vehicle body panel and a method for manufacturing the weld nut.

[0002]

2. Description of the Related Art Conventionally, as shown in, for example, Japanese Patent Laid-Open No. 63-34313, a pressure electrode surface of a weld nut,
That is, a concave seat is formed on the upper end surface located on the opposite side of the base end surface to be welded to the attached portion so as to surround the screw hole, and the seal member made of a flexible member such as paper or vinyl is formed in the concave seat. Is fitted to cover the upper surface of the screw hole. The weld nut with this configuration prevents the undercoat material from entering the screw hole when the rust preventive material and the undercoat material are applied to the vehicle body while being welded and fixed to the vehicle body. can do.

[0003]

When the sealing member is fitted into the recessed seat formed on the pressure electrode surface of the weld nut as described above so as to cover the upper surface of the screw hole, Since the recessed seat for fitting the seal member must be provided in the peripheral portion of the screw hole, a commercially available weld nut cannot be used, and the manufacturing cost is high, and the recessed seat is deep. There is a problem that the length of the screw portion is shortened by an amount corresponding to the length. In addition, if the seal member made of the above vinyl material cannot be properly attached to the recess seat of the weld nut and the seal member is lifted, the pressure electrode surface of the weld nut is insulated by the seal member and the weld member is welded. This causes a problem that the nut cannot be welded.

Then, after welding the weld nut to which the above-mentioned seal member is attached to the portion to be attached and screwing a bolt for attaching a component to the weld nut, the seal member is separated from the weld nut and falls onto the assembly line. Therefore, there is a problem that complicated work is required to remove the seal member from the assembly line.

It is also practiced to apply a masking tape to the portion where the weld nut is attached to cover the upper surface of the screw hole and spray an undercoat material. In this case, the masking tape is used. After installing the undercoat material at a predetermined position, it is necessary to spray the undercoat material and then remove the masking tape. Since the non-application portion is formed, there is a problem that the undercoat material may not be applied to a necessary portion.

The present invention has been made in order to solve the above-mentioned problems, and a commercially available weld nut can be used to easily and properly cover the upper surface of the screw hole thereof. When screwing the bolt,
An object of the present invention is to provide a weld nut capable of preventing the seal material covering the screw hole from coming off from the weld nut, and a method for manufacturing the weld nut.

[0007]

The invention according to claim 1 is
A nut main body having a welding projection formed at the base end, and a sealing material made of a metal plate welded to the upper end surface of the nut main body, the sealing plate having a positioning hole and a slit surrounding the positioning hole. Is formed, and a connecting portion that connects the portion surrounded by the slit and the outer peripheral portion thereof is provided.

According to a second aspect of the present invention, a positioning hole is formed in a sealing material made of a metal plate, and a slit having a size corresponding to a screw hole of a weld nut is formed around the positioning hole, and then a welding machine is provided. The nut body is externally fitted to the positioning pin provided on the installation portion of the positioning member for positioning, and the protrusion protruding from the upper end portion of the positioning pin is fitted into the positioning hole of the sealing material to thereby provide the sealing material. And the nut body are aligned with each other, the sealing material is welded to the upper surface of the nut body.

[0009]

According to the first aspect of the present invention, the upper end surface of the screw hole is covered by the central portion of the seal material by welding the sealing material to the upper end surface of the weld nut centering on the positioning hole. Become. Then, when the bolt is screwed onto the nut body and the tip of the bolt comes into contact with the central portion of the sealing material, the central portion bends around the connecting portion with the outer peripheral portion as a fulcrum, and is bent from the upper end surface of the nut body. It will deform so as to be separated.

According to the second aspect of the present invention, the seal material is welded to the upper end surface of the nut body in a state where the nut body and the seal material are aligned with each other by the positioning pin provided in the installation portion of the welding machine. By doing so, the central portion of the sealing material defined by the slit formed in the sealing material is arranged at a position corresponding to the screw hole of the nut body.

[0011]

1 and 2 show an embodiment of a weld nut according to the present invention. This weld nut is a commercially available nut body 2 having a welding projection 1 formed at a corner portion of a base end portion. And a sealing material 3 welded to the upper end surface of the nut body 2. The sealing material 3 is made of a metal plate such as a steel plate material, and is provided with a positioning hole 4 formed of a punched hole formed in the center thereof, and a slit 5 formed so as to surround the positioning hole 4. .. The slit 5 is formed in an arc shape having a diameter larger than the diameter of the screw hole 6 of the nut body 1, and has a disk-shaped central portion 7 partitioned by the slit 5 and an outer peripheral portion located outside thereof. 8 are connected to each other by a connecting portion 9 having a predetermined width.

In order to manufacture the above-mentioned weld nut, the process shown in FIG.
As shown in FIG. 3, a metal plate 10 having a predetermined width, which is a raw material of the sealing material 3, is unwound from the original fabric and is pressed by a press molding machine 11.
The upper mold 15 of the press molding machine 11
Then, the positioning hole 4 and the slit 5 and the cutting groove 14 are sequentially formed on the metal plate 10 at predetermined intervals by the lower die 16. That is, the upper mold 15 of the press machine 11
While intermittently feeding the metal plate 10 between the lower mold 16 and
By operating the press machine 11, the positioning hole 4 is punched and formed in the first stage, the slit 5 surrounding the positioning hole 4 is punched and formed in the second stage, and then the slit 5 is formed in the third stage. Sealing material 3 on the outer periphery of
The concave groove 14 having a V-shaped cross section and having a size corresponding to is pressed (see FIG. 4).

Then, the metal plate 10 led out from the press machine 11 is supplied to the installation section B of the welding machine 17, and the lower electrode 18 of the welding machine 17 is supplied as shown in FIG.
The nut body 2 is attached to the positioning pin 19 protruding from the upper end surface of the
To fit and position. Then, the positioning pin 1
When the positioning hole 4 formed in the metal plate 10 reaches above the protrusion 20 provided on the upper end surface of the metal plate 9, the upper electrode 21 of the welding machine 17 is lowered to push down the metal plate 10. As a result, the positioning hole 4 of the metal plate 10 is fitted onto the protrusion 20 and the metal plate 10 is pressed against the upper end surface of the nut body 2. In this state, both electrodes 18, 2
A welding current is passed between the two to weld the inner peripheral portion of the concave groove 14, that is, the portion corresponding to the outer peripheral portion of the sealing material 3, to the upper end surface of the nut body 2.

The metal plate 10 led out from the welding machine 17
The nut body 2 is supplied to the installation portion C of the punching machine 22 and the concave groove 14 of the metal plate 10 is sheared, so that the seal member 3 is separated from the metal plate 10.
In this way, a weld nut in which the sealing material 3 is welded to the upper end surface of the nut body 2 is manufactured. In addition, the metal plate 10 led out from the punching machine 22 has a recovery section D.
In, it is cut into a predetermined length and collected.

The weld nut manufactured as described above is, as shown in FIG. 5, welded to a mounting portion of the vehicle body panel 23, and thereafter, a rust preventive material is electrodeposited and optionally, if necessary. The undercoat material is spray coated. Then, as shown in FIG. 6, a bolt 24 for attaching a component is screwed to the weld nut, and when the tip end portion of the bolt 24 abuts on the central portion 7 of the sealing material 3, the connecting portion 9 bends. The central portion 7 is deformed so as to be separated from the upper end surface of the nut body 2.

Since the sealing material 3 is welded to the upper end surface of the nut body 2 and the central portion 7 of the sealing material 3 covers the upper surface of the screw hole 6 as described above, when the undercoat material is spray-painted. In addition, the sealing material 3 can effectively prevent the undercoat material from adhering to the screw hole 6. Further, since the positioning hole 4 and the slit 5 are formed in the sealing material 3, when the vehicle body is dipped in the electrodeposition paint tank to apply the electrodeposition coating, the screw hole 6 is formed.
The inside air can be led out from the positioning hole 4 to the outside, and when the vehicle body is led out of the electrodeposition paint tank, the electrodeposition paint that has penetrated into the screw hole 6 can be quickly released to the outside from the positioning hole 4. Can be discharged.

Since the positioning hole 4 is formed in the metal plate 10 and the slit 5 and the concave groove 14 are formed around the positioning hole 4, the positioning hole 1 is formed.
The metal plate 10 and the nut body 2 are aligned with each other by using 7 to weld the two so that the central portion 7 defined by the slit 5 accurately corresponds to the screw hole 6 of the nut body 2. In addition to the above, the recessed groove 14 of the metal plate 10, that is, the outer peripheral portion of the seal material 3 can be installed so as to accurately correspond to the outer peripheral portion of the upper end surface of the nut body 2.

Since the sealing material 3 is divided into the central portion 7 corresponding to the screw hole 6 of the nut body 2 and the outer peripheral portion 8 by forming the slit 5, the nut body 2 is formed.
When the bolt 24 for mounting the component is screwed on the member, the central portion 7 is deformed so as to be separated from the upper end surface of the nut body 2, so that the bolt 24 is sealed at a position that does not interfere with the screwing. The central portion 7 of the material 3 can be retracted. Further, since the central portion 7 and the outer peripheral portion 8 are connected to each other by the connecting portion 9, when the central portion 7 of the sealing material 3 is retracted as described above, the central portion 7 is not attached to the nut body 2. It can be prevented from falling out.

Further, since the sealing material 3 is formed of the metal plate 10, the sealing material 3 can be easily fixed to the nut body 2 by electric welding, and at the same time, the sealing material can be electrodeposited during the electrodeposition coating. The paint can be properly applied to prevent rust. Further, since the sealing material 3 is made of a conductor, the electrical continuity of the weld nut is reliably maintained, and the welding nut is attached to the vehicle body panel 23 or the like regardless of how the sealing material 3 is attached. It is possible to perform electric welding to the attached part in a proper state. That is, even when the entire upper end surface of the weld nut is covered with the sealing material 3, the pressure electrode surface of the weld nut is not electrically insulated, and the weld nut is always attached to the mounted portion. It can be installed by electric welding.

In the above embodiment, the slit 5 of the sealing material 3 is formed in a circular arc shape corresponding to the outer peripheral portion of the screw hole 6, but the shape of the slit is limited to the above embodiment. Various modifications can be made without, for example, as shown in FIG. 7, a large number of slits 5a extending radially from the positioning hole 4 are provided, and a fan-shaped central portion 7a defined by the slits 5a is provided at its base end. A part may be connected to the outer peripheral part 8. According to this structure, each central portion 7a of the sealing material 3 is bent at the base end portion when the component mounting bolt 24 is screwed,
Each of them is deformed so as to be separated from the upper end surface of the nut body 2.

[0021]

As described above, in the weld nut according to the present invention, the sealing material made of a metal plate is welded to the upper end surface of the nut body, and the central portion of the sealing material covers the upper surface of the screw hole. With this configuration, it is possible to effectively prevent the undercoat material from adhering to the screw holes by the sealing material when the undercoat material is spray-painted.

Further, since the positioning hole and the slit surrounding the positioning hole are formed in the sealing material, the sealing material and the nut body are properly aligned by utilizing the positioning hole when welding the sealing material, and the slit is formed. It is possible to install the center part divided by the so as to correspond exactly to the screw hole of the nut body, and to install the outer peripheral part of the sealing material so as to correspond exactly to the outer peripheral part of the upper end surface of the nut body made of a commercial product. Can be welded in the state. Furthermore, when the weld nut is dipped in an electrodeposition paint tank to perform electrodeposition coating, the internal air and the electrodeposition coating can be quickly discharged to the outside by utilizing the positioning holes as holes. There is an advantage that.

Since the sealing material is divided into the central portion corresponding to the screw hole portion and the outer peripheral portion by forming the slit, the central portion is fixed when the bolt for mounting the component is screwed into the nut body. By deforming the nut body so that it is separated from the upper end surface of the nut body, the central portion of the sealing material can be retracted to a position that does not interfere with screwing the bolt, and the central portion and the outer peripheral portion are separated from each other. Since the connecting portion for connecting is provided, there is an advantage that when the seal material is retracted as described above, the seal material is prevented from coming off from the nut body, and the recovery work or the like is unnecessary.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a weld nut according to the present invention.

FIG. 2 is a sectional view showing an assembled state of the weld nut.

FIG. 3 is an explanatory view showing an embodiment of a method for manufacturing a weld nut according to the present invention.

FIG. 4 is a cross-sectional view showing a welding process of a seal member and a nut body.

FIG. 5 is a cross-sectional view showing an attached state of a weld nut.

FIG. 6 is a cross-sectional view showing a state in which a bolt is screwed onto a weld nut.

FIG. 7 is a plan view showing another embodiment of the weld nut according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Welding protrusion 2 Nut body 3 Sealing material 4 Positioning hole 5 Slit 6 Screw hole 7 Central part (part divided by slit) 8 Outer peripheral part 9 Connecting part 10 Metal plate 17 Welding machine 19 Positioning pin 20 Projection part

Claims (2)

[Claims] 1. A nut main body having a welding projection formed at a base end thereof, and a sealing member made of a metal plate welded to an upper end surface of the nut main body. The sealing plate has a positioning hole and the positioning hole. A weld nut that is formed with a slit that surrounds the slit, and that is provided with a connecting portion that connects the portion surrounded by the slit and the outer peripheral portion thereof. 2. A sealing material made of a metal plate is provided with a positioning hole, and a slit having a size corresponding to the screw hole of the weld nut is formed around the positioning hole, and then provided at the installation portion of the welding machine. The nut body is externally fitted and positioned on the positioning pin, and the protrusion provided on the upper end of the positioning pin is inserted into the positioning hole of the sealing material to thereby separate the sealing material and the nut body. A method for manufacturing a weld nut, wherein the sealing material is welded to the upper surface of the nut body in a state of being aligned.