JPH0636335Y2 - Screw grommet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a screw grommet for attaching a component to another component. The screw grommet of the present invention is effective when used for attaching parts such as moldings to vehicle body panels in automobiles,
It is not limited to such an application.

[Prior art]

For example, a resin screw grommet used to attach a rear windshield molding of an automobile to a vehicle body has a grommet body inserted into a mounting hole formed in a vehicle body panel, and a screw part is screwed into an axial hole of the grommet body. Then, the shaft portion of the grommet main body is expanded outward in the radial direction to obtain a coupling relationship with the vehicle body panel. For this purpose, a step for locking is formed on the outer surface of the shaft of the grommet body, and when the shaft is expanded radially outward by a screw part, this step is engaged with the back side of the vehicle body panel. To prevent falling.

With this type of screw grommet, the locking step formed on the shaft of the grommet body cannot be made too high in order to facilitate the mounting operation. Therefore, even when the shaft portion is expanded, there is a problem that a sufficient engagement margin cannot be obtained between the step portion and the vehicle body panel, and the engagement holding force is weak.

As a structure capable of solving the problem of this engaging force, a screw grommet including a grommet body and a nut piece that is drawn into a shaft hole of the grommet body and expands the shaft portion of the grommet body radially outward is known. ing. In this type of conventionally known screw grommet, the shaft part of the grommet body is divided into a plurality of legs by slits, etc., the nut piece has a shaft hole that engages with the screw part, and the nut piece is the leg part of the grommet body. Is located adjacent to the end of the grommet body, the screw part is passed through the shaft hole of the grommet body to engage with the nut piece, and the nut part can be drawn into the shaft hole of the grommet body by rotating the screw part. it can. This screw grommet can determine the expansion amount of the leg by appropriately determining the outer surface shape of the nut piece and the inner surface shape of the shaft portion of the grommet body, so it is possible to design with sufficient engagement margin. is there. Conventionally, a structure in which a nut piece is connected to a grommet body by a thin portion and a structure in which the nut piece is embedded in the grommet body are known.

[Problems to be solved by the device]

In a conventional screw grommet consisting of a grommet body and a nut piece that is drawn into the shaft hole of the grommet body and expands the shaft portion of the grommet body outward in the radial direction,
After once used for attachment, the grommet body and the nut piece are separated from each other, so that it is impossible to remove and reuse after use, or it is very inconvenient.

Therefore, it is an object of the present invention to solve the problem of the conventional screw grommet that is not reusable or very inconvenient. That is, the present invention is
It is an object of the present invention to provide a screw grommet which is composed of two parts, a grommet body and a nut piece, and which is easy to reuse.

[Means for Solving the Problems]

In order to solve the above-mentioned problem, in the present invention, the nut piece is configured so that it can be locked to the grommet body at two positions, that is, a state in which the shaft portion of the grommet body is not expanded and a state in which it is expanded. In more detail, the grommet body has a locking step on the inner surface of the shaft, and the nut piece has a leg part of the shaft of the grommet body or a locking step in an unexpanded state. A first locking portion that can be engaged is provided near one end, and a second locking portion that can be engaged with the locking step in the state where the leg is expanded is separated from the first locking portion toward the other end. It is formed in the open position.

[Action]

In the screw grommet of the present invention, the first locking portion of the nut piece is engaged with the locking step portion of the grommet body during manufacturing and distribution. At this time, a screw component such as a tap screw may be inserted from the grommet body side in advance and engaged with the nut piece. In this state, the shaft portion of the grommet body does not expand, and the screw grommet can be inserted into the mounting hole formed in the component such as the vehicle body panel while keeping the screw grommet as it is. Since all the parts necessary for mounting the screw grommet are pre-assembled, the mounting work on the vehicle body panel etc. can be performed very easily.

At the time of mounting, parts such as moldings are mounted on the head of the grommet body, and the screw grommets are inserted into mounting holes formed in the vehicle body panel or the like. Then
Screw the threaded part onto the nut piece. If no screw is formed in the shaft hole of the nut piece, use a tap screw as a screw component. The tap screw bites into the nut piece while forming a screw in the shaft hole of the nut piece, and draws the nut piece into the grommet body. If a screw has been previously formed in the shaft hole of the nut piece,
Conventional screws can be used as threaded parts. Also in this case, the nut piece can be pulled into the grommet body by screwing the screw component into the nut piece.

When the nut piece is pulled into the grommet body, the nut piece expands the leg portion of the shaft portion of the grommet body radially outward. Therefore, the shaft portion of the grommet body has a shape that bulges from the mounting hole on the back side of the mounting side component such as the vehicle body panel and is held so as not to fall off from the mounting side component. In this state, the second locking portion of the nut piece engages with the locking step portion of the grommet body. Therefore, even if the threaded part may come off the grommet body,
The grommet body itself is firmly held by the mounting side component.

When the screw grommet is removed, the screw part engaged with the nut piece is rotated in the loosening direction. Due to this rotation, the screw parts are lifted. here,
When the head of the screw component is tapped, the engagement between the second locking portion of the nut piece and the locking step portion of the grommet body is released, the nut piece is pushed out of the grommet body, and the first locking portion of the nut piece is released. Engages with the locking step of the grommet body. In this state, the shaft portion of the grommet body is returned to the position where it does not expand. Therefore, the grommet can be pulled out from the mounting hole of the mounting side component. Reuse can be performed by repeating the same procedure.

〔Example〕

1 (a), (b), (c) and (d) show a grommet main body in a screw grommet of the first embodiment of the present invention. The grommet body is generally designated by reference numeral 1 and includes a head portion 2 and a shaft portion 3. The head 2 is a flange having a quadrangular planar shape as shown in FIG. 1 (b).
2a and a projecting portion 2b extending laterally from the flange 2a. A molding mounting portion 4 is provided so as to extend obliquely upward from the projecting portion 2b. The molding attachment portion 4 is formed on the same side as the pair of elastic pieces 5 extending obliquely in a square shape, the molding locking claws 6 formed on the side opposite to the direction in which the elastic pieces 5 extend, and the elastic piece 5. It consists of a locking claw 7.

The shaft 3 has a pair of legs 9 extending downward from the center of the flange 2 a of the head 2 and divided by a slit 8.
The leg 9 has an outwardly projecting pawl 9a for engaging the vehicle body panel. As shown in FIG. 1 (d), each leg 9
Has a U-shaped cross section, and a locking step 9b is formed on the inner surface of the bottom of the U-shape. A groove 9c is formed by cutting out the center of the locking step 9b. Flange 2a of head 2
A hole 10 is formed in the center of the. The hole 10 is formed so as to communicate with a quadrangular space formed between the pair of legs 9. As shown in FIG. 1 (b), on the upper surface of the flange 2a, an annular lip 10a is formed on the edge of the hole 10, and a circular wall 11 is formed so as to surround the hole 10 on the outer side thereof.
A part of this wall 11 is cut away on the opposite side of the projecting portion 2b.

Nut pieces used in combination with this grommet body 1
12 is shown in FIGS. 2 (a) (b) (c). This nut piece 12
Has a head portion 13 having a quadrangular cross section and a shaft portion 14 extending in one direction from the head portion 13. The shaft hole penetrates the nut piece 12 in the axial direction.
15 are formed. The shaft hole 15 has a large diameter portion 15a formed in a predetermined length from the head 13 side and a small diameter portion 15b formed continuously with the large diameter portion 15a. The large-diameter portion 15a is formed to have a diameter slightly larger than the outer diameter of the tap screw, which is a screw piece screwed into the nut piece 12. The small diameter portion 15b is
The diameter is slightly larger than the root diameter of the threaded portion of the tap screw.

The shaft portion 14 of the nut piece 12 has a substantially quadrangular cross-sectional shape,
A bulging portion 14a laterally protruding is formed at a position slightly lower than the head portion 13 on the two side surfaces facing each other. Shaft 1
A ridge 16 extending in the axial direction is formed on another side surface of the other 4 facing each other. A locking shoulder portion 17 is formed as a first locking portion between the head portion 13 and the shaft portion 14. Further, the bulge 14
A locking shoulder 18 is formed on a as a second locking portion. A ridge 14b is formed on the side surface where the bulging portion 14a is formed.

FIG. 3 shows an assembled state of the screw grommet of this embodiment. The head portion 13 of the nut piece 12 is inserted from below into the shaft portion 3 of the grommet body 1, and the locking shoulder portion 17 of the nut piece 12 engages with the locking step portion 9b of the shaft portion of the grommet body 1. . The protrusion 16 formed on the side surface of the nut piece 12 engages with the slit 8 formed on the shaft portion 3 of the grommet body 1, and the protrusion 14b formed on the other side surface is formed on the inner surface of the leg portion of the grommet body 1. It engages with the groove 9c. In this state, the tap screw 19 is screwed into the nut piece 12 through the hole 10 of the grommet body 1. The screw grommet is sent to the molding manufacturer in the state of being temporarily assembled in this way.

FIG. 4 shows a state in which the molding 20 is attached. The molding 20 includes a molding part 20a and a rubber cover part 20b arranged along the length of the molding part 20a and covering the screw grommet. The molding portion 20a is attached to the molding attachment portion 4 of the grommet body 1. When installing this,
The folded back portion 20c on one side of the molding portion 20a is engaged with the locking claw 6 of the molding mounting portion 4, and the folded back portion 20d on the opposite side is engaged with the locking claw 7. The elastic piece 5 engages with the back side of the folded portion 20d. The cover 20b is arranged so as to cover the head 2 of the grommet body 1. A packing 21 is attached to the lower surface of the head 2 of the grommet body 1 as required. In this state, the product is supplied to the automobile assembly plant.

5 and 6 show the screw grommet mounting process. As shown in FIG. 5, the screw grommet to which the molding 20 is attached is a body panel 22.
It is inserted into the mounting hole 22a formed in the. Here, the tap screw 19 is screwed into the nut piece 12 by the driver 23. By this screwing, the nut piece 12 is drawn into the shaft portion 3 of the grommet body 1, and the shaft portion 14 of the nut piece 12 is
The bulged portion 14a formed on the grommets enters between the leg portions 9 of the shaft portion 3 of the grommet body 1 and pushes the leg portions 9 open. This state is shown in FIG. Since the leg portion 9 of the grommet body 1 is sufficiently pushed open, the screw grommet is attached to the body panel 22.
There is no fear of falling out of it. In this state, the locking shoulder 18 of the nut piece 12 has the locking step 9b of the shaft portion 3 of the grommet body 1.
Engage with. Therefore, there is no risk that the nut piece 12 will fall out of the grommet body 1, and it is safe even if the tap screw 19 loosens. Also tap screw
The lower surface of the head of 19 is a flange of the head of the grommet body 1.
It prevents the water from leaking from the hole 10 by contacting the lip 10a formed on the 2a.

When removing the screw grommet, the screw 19 is rotated in the returning direction in the state shown in FIG. This operation causes the screw 19 to float. Then, when the head of the screw 19 is tapped, the engaging shoulder 18 of the nut piece 12 is disengaged from the engaging step 9b of the shaft portion 3 of the grommet body 1, and the nut piece 12 is pushed outward. The locking shoulder 17 which is the first locking portion is engaged with the locking step 9b, and the state shown in FIG. 5 is obtained. Therefore, the screw grommet can be removed from the vehicle body panel 22, and even when it is removed,
Grommet body 1, nut piece 12, and tap screw
19 is kept in the assembled state.

7 to 10 show another embodiment of the present invention. 7 (a), (b) and (c) show the nut pieces in the screw grommet of this embodiment, and the corresponding parts are designated by the same reference numerals as in the previous embodiment. In this embodiment, a screw is formed on the small diameter portion 15b of the shaft hole 15 of the nut piece 12. In order to facilitate the molding, the screw is a half screw in this embodiment, but of course, it may be a full screw.

Referring to FIGS. 8A and 8B, the grommet body 31 of this embodiment is a head for attaching a retainer described later.
32 and a shaft portion extending from the head portion 32. On the upper surface of the head portion 32, there is formed a dish-shaped recess 32a adapted to the dish shape of the retainer. A suction cup portion 32b that contacts the vehicle body panel is formed on the lower side of the head portion 32. A shaft hole 34 is formed so as to penetrate from the head portion 32 to the shaft portion 33. The shaft portion 33 is composed of a pair of leg portions 36 divided by a slit 35, and a locking step portion 37 is formed on the inner surface of the leg portion 36. A bulge portion 38 is formed on the outer side surface of the shaft portion 33.

FIG. 9 shows the assembled state of the grommet body 31 and the nut piece 12 of this embodiment. The assembled state is the same as that of the previous embodiment, so detailed description will be omitted. FIG. 10 shows a usage state. A dish-shaped retainer 40 is arranged on the head 32 of the grommet body 31, and a screw 41 is passed through the grommet body 31 from the retainer 40 and screw-engaged with the nut piece 12. Then, when the screw 41 is rotated using the driver 23, the nut piece 12 is drawn into the shaft portion 33 of the grommet body 31. Other functions are the same as in the previous embodiment.

〔effect〕

In the present invention, the grommet body of the screw grommet is formed with the locking step portion, and the nut piece is provided with two locking portions that engage with the locking step portion, and the first locking portion is Since the shaft portion of the grommet body is engaged with the locking step portion in a state where it is not expanded, the second locking portion is engaged with the locking step portion in a state where the shaft portion of the grommet body is expanded. The nut piece can be held in the assembled state in the grommet body before and after the screw grommet is attached, and after the attachment, the nut piece can be arbitrarily returned to the state before the attachment. Therefore, it is easy to remove the screw grommet after mounting and it can be reused.

[Brief description of drawings]

FIG. 1 (a) is a side view showing a part of a grommet body in a cross section in one embodiment of the present invention, FIG. 1 (b) is a plan view thereof, and FIG. 1 (c) is FIG. 1 (a). CC line sectional view in Fig. 1, Fig. 1 (d) is a DD line sectional view in Fig. 1 (a), Fig. 2 (a) is a front view of the nut piece in this embodiment, and Fig. 2 (b) is Second, the BB line sectional view of FIG.
FIG. 6C is a plan view of the nut piece, FIG. 3 is a vertical sectional view showing an assembled state of the screw grommet, and FIG. 4 is a vertical sectional view showing a state in which the molding is attached to the screw grommet, FIGS. 5 and 6. FIG. 7 is a sectional view showing a mounting process, FIG. 7 (a) is a front view of a nut piece according to another embodiment of the present invention, FIG. 7 (b) is a side view of the nut piece, and FIG. 7 (c). Is a transverse sectional view, FIG. 7 (d) is a longitudinal sectional view, FIG. 8 (a) is a front view showing a part of the grommet body by cutting out, and FIG. 8 (b) is showing a part by cutting out. A side view, FIG. 9 is a sectional view showing an assembled state of the screw grommet, and FIG. 10 is a sectional view showing an attaching step. 1 ... Grommet body, 2 ... Head, 3 ... Shaft, 4 ... Molding mounting part, 9 ... Leg, 9a ... Locking claw, 9b ... Locking step, 12 ... Nut piece, 14 …… Shaft, 15 …… Shaft hole, 17 …… Shoulder shoulder, 18 …… Shoulder shoulder.

Claims (5)

[Scope of utility model registration request] 1. A head attached to a component and a shaft extending in one direction from the head are provided, a shaft hole is formed in the shaft, and the shaft can expand radially outward. A grommet body having a pair of legs and a shaft hole engageable with a screw part, and when the grommet body is pulled into the shaft portion, pushes the leg portion of the shaft portion outward in the radial direction. In a screw grommet consisting of a nut piece that has a protruding portion that protrudes radially outward so as to open,
A locking step is formed on the inner surface of the shaft of the grommet body, and the nut piece engages with the locking step of the shaft of the grommet body in a state where the leg is not expanded. A first locking portion that can be fitted is provided near one end portion, and a second locking portion that can be engaged with a locking step portion of the shaft portion of the grommet body in a state where the leg portion is expanded is the first engaging portion. A screw grommet formed on the outer surface of the projecting portion at a position away from the stopper in the other end direction. 2. The screw grommet according to claim 1, wherein the shaft hole of the nut piece includes a large diameter portion extending from the one end side and a small diameter portion continuous with the large diameter portion. The part has a diameter slightly larger than the outer diameter of the threaded part, the small diameter part has a diameter slightly larger than the diameter of the thread root of the threaded part, and the inner surface of the shaft hole can be threaded by the threaded part. Grommet made of elastic material like. 3. The screw grommet according to claim 1, wherein the shaft hole of the nut piece is configured as a screw hole that screw-engages with the screw component. 4. The screw grommet according to any one of claims 1 to 3, wherein a protrusion that engages with a slit between the legs of the grommet body is provided on the outer surface of the nut piece for preventing rotation. Formed screw grommet. 5. The screw grommet according to claim 1, wherein an axially extending groove is formed on an inner surface of the shaft hole of the grommet body, and a rotation stopper is provided on an outer surface of the nut piece. Therefore, a screw grommet having a protrusion that engages with the groove.