JPH09133114A - Plastic fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To from a screw with a two-plane split metal mold, making it removable with a coin or the like at hand by forming one line of a grooved part, passing through the shaft center of a shank and opened with both ends to a peripheral edge of a head part, a top face of the screw head. SOLUTION: When Two panels 20 and 30 are supposedly locked with a fastener 10, a leg part 42 of the grommet 40 is inserted into two through holed 21 and 31 piercing through both these panels 20 and 30, and a flange 41 is made to contact with a surface of the panel 20. Next, a shank 52 of a screw 50 is screwed in an insertional hole 43 of the gromment 40. With this, the leg part 42 of the gromment 40 is pushed by the shank 53 of the screw 50 and thereby it is gradually expanding of its diameter. Therefore, the leg part 42 of the gromment 40 becomes unslipped out of these through holes 21 and 31, and thus both these panels 20 and 30 are supposedly clamped tight. In contrast to, when these two panels 20 and 30 supposedly clamped tight are separated from each other, a flat tip screwdriver or the like is inserted into a groove part 54 installed a head part 53 of the screw 50, rotating the screw, and it is pulled out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastener made of plastic, which facilitates the production of a die and the attachment / detachment of the fastener.

[0002]

2. Description of the Related Art Conventionally, this type of fastener has been constructed of a grommet and a screw (for example, Japanese Unexamined Patent Publication No. 62-62160).
-33446 gazette etc.). The above-mentioned conventional grommet is a flange, a leg portion that is extended from the lower surface of the flange and is capable of expanding the outer diameter, and an insertion hole that is provided in the axial direction from the upper surface of the flange toward the leg portion, The internal thread portion provided on the inner wall of the insertion hole is provided.

Further, in the above-mentioned conventional screw, the shaft is inserted into the insertion hole of the grommet to expand the diameter of the leg portion, and the outer peripheral surface is provided with a male screw portion for engaging with the female screw portion of the insertion hole. And a head provided on the upper end of the shaft. On the upper surface of the head of the screw, there was formed a plus groove depressed in a cross shape into which a plus driver could be inserted.

On the other hand, the grommet and the screw were integrally molded by plastic molding using a mold with two surfaces. Since the screw had a plus groove recessed in a cross shape, a slider or thread cutting was required due to the structure of the mold.

[0005]

However, in the above-described conventional fastener, since the slider or the thread cutting is required to mold the screw, the die cost is also high,
There is the first problem that the manufacturing process becomes complicated, the manufacturing is troublesome, and it is difficult to reduce the manufacturing cost.

There is also a second problem that a Phillips screwdriver is required when removing the screw. Therefore, the invention according to claim 1 has been made in view of the problems of the above-described conventional technique, and the purpose thereof is as follows. That is, according to the invention of claim 1, not only the mold can be easily manufactured and the manufacturing cost can be reduced, but also the screw can be removed by using a familiar coin or the like without using a tool such as a Phillips screwdriver. It is intended to provide a plastic fastener that can be used.

[0007] The second aspect of the present invention is the first aspect of the present invention.
In addition to the objects of the invention described above, the following objects are provided. That is, the invention according to claim 2 is such that a screw or the like can be easily rotated by inserting a coin or the like into the groove formed in the space between the pair of blocks.

[0008] The third aspect of the present invention is the first aspect of the present invention.
Alternatively, in addition to the object of the invention as set forth in claim 2, the following objects are provided. That is, in the invention according to claim 3, since each block is formed in a symmetrical fan shape centering on the groove,
The width of the groove at both ends of the groove can be set to be wide so that a coin or the like can be inserted easily.

[0009]

[Means for Solving the Problems]

(Features) The present invention is for achieving the above-mentioned object, and its contents will be described below with reference to embodiments of the invention shown in the drawings. The invention according to claim 1 is characterized by the following points.

That is, on the upper surface of the head (53) of the grommet (40), as shown in, for example, FIGS. One groove open to
(54) is formed. The invention described in claim 2 is characterized by the following points in addition to the characteristic points of the invention described in claim 1.

That is, as shown in FIG. 4, for example, the groove (64) has a pair of blocks (6) protruding from the upper surface of the head (63).
It is formed within the interval of 5). The invention according to claim 3 is
In addition to the features of the invention described in claim 1 or 2, the following features are provided. That is, each block (83)
Is formed in a fan shape symmetrical with respect to the groove (84) as shown in FIG. 6, for example. (Operation) Next, the operation of each invention described in each claim having the above-mentioned features will be described below.

According to the first aspect of the invention, the following operation is provided. That is, the groove (54) of the screw (50) is
For example, as shown in FIGS. 1 and 2, since the shaft (52) passes through the center of the shaft and both ends are open to the peripheral edge of the head (53), the screw (50) is divided into two surfaces although not shown. It can be molded using a mold without the need for sliders or threading.

On the other hand, in order to fix the two panels (20, 30) in a superposed manner by using the fastener (10), for example, as shown in FIGS.
As shown in, through holes that penetrate both panels (20, 30)
The leg portion (42) of the grommet (40) is inserted into the (21, 31), and the flange (41) is brought into contact with the surface of the panel (20) on one side. Next, as shown in FIG. 3, the shaft portion (52) of the screw (50) is press-fitted into the insertion hole (43) of the grommet (40).

Thereby, the leg portion (42) of the grommet (40)
However, as shown in FIG. 3, for example, the shaft portion (52) of the screw (50) is
It is pushed by and gradually expands in diameter. For this reason, grommets (40)
The legs (42) of the two panels are, for example, as shown in FIG.
Both panels cannot be removed from the through holes (21, 31) of (20, 30).
(20,30) are fixed in a polymer form.

On the other hand, in order to separate the two panels (20, 30) fixed in a superposed manner, the groove (54) provided in the head (53) of the screw (50) is not shown. , Insert a flat-blade screwdriver or coin, and remove the screw (50) and rotate it in the removing direction. When the screw (50) is rotated, the male screw part (44) of the shaft part (52) and the insertion hole (43) of the grommet (40).
The shaft portion (52) of the screw (50) is gradually removed from the inside of the insertion hole (43) of the grommet (40) due to the engagement with the female screw portion (44) inside.

For this reason, the leg portion (42) of the grommet (40) is gradually reduced in diameter so as to come out from the through holes (21, 31) of the two panels (20, 30), so that both panels (20, 30) are removed. Separate from each other. According to the invention described in claim 2, in addition to the operation of the invention described in claim 1, the following operation is achieved. That is, as shown in FIG. 4, for example, a slotted screwdriver or a coin (not shown) is inserted into the groove (64) formed in the space between the pair of blocks (65), and the screw (50) is rotated in the removing direction. Just do it.

According to the invention of claim 3, in addition to the operation of the invention of claim 1 or claim 2, the following operation is achieved. That is, as shown in FIG. 6, for example, as shown in FIG. 6, the groove width of the both ends of the groove portion (84) can be set wide, so that a slotted screwdriver, a coin or the like can be easily inserted although not shown.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Example) FIGS. 1 to 3 show a first example of the embodiment of the present invention. 1 is an exploded sectional view of the fastener, FIG. 2 is an exploded side view of the fastener, and FIG. 3 is a sectional view showing a usage state. (Fastener) In FIGS. 1 to 3, 10 indicates a fastener 10, which can be used, for example, for mounting parts of an automobile or assembling electrical products. In this embodiment,
Fasteners 10 are used to secure the two panels 20, 30 in a superposed fashion, as shown in FIGS.

As shown in FIGS. 1 and 2, the fastener 10 is composed of a grommet 40 and a screw 50 fitted to the grommet 40. And grommet 40,
In addition, the screw 50 is formed of plastic having elasticity and flexibility. (Grommet) As shown in FIGS. 1 and 2, the grommet 40 includes a flange 41, a leg portion 42 extending from the lower surface of the flange 41 and capable of expanding the outer diameter, and a leg portion from the upper surface of the flange 41. It has an insertion hole 43 provided axially toward 42 and a female screw portion 44 provided on the inner wall of the insertion hole 43.

As shown in FIGS. 1 and 2, the leg portion 42 is divided into left and right by a slit 45 vertically cut from the lower end portion of the leg portion 42 along the axial center. And legs
42 can be expanded or contracted by the slit 45. Further, the leg portion 42 is formed in a tapered shape in which the diameter is reduced toward the tip in the state before being attached to the panels 20 and 30, and the insertion hole 43 is also in a tapered shape in which the diameter is reduced toward the tip. ing.

As shown in FIGS. 1 and 2, on the outer periphery of the upper end of the leg portion 42, there is provided a seat portion 46 conforming to the inner peripheral shape of the through holes 21, 31 formed in the panels 20, 30. The female screw portion 44
As shown in FIG. 1, a plurality of ridges inclined in the spiral direction are provided facing each other on the upper portion of the inner wall of the insertion hole 43. The female screw portion 44 may be provided over the entire circumference of the inner wall of the insertion hole 43. (Screw) As shown in FIGS. 1 and 2, the screw 50 is inserted into the insertion hole 43 of the grommet 40 to expand the diameter of the leg portion 42 and engage the female screw portion 44 of the insertion hole 43 on the outer peripheral surface. And a large-diameter head portion 53 provided at the upper end of the shaft portion 52.

As shown in FIGS. 1 and 2, the shaft portion 52 has an outer diameter substantially the same as the inner diameter of the insertion hole 43 of the grommet 40 and a length substantially the same as the depth of the insertion hole 43 of the grommet 40. have. In addition, a spiral thread is formed on the outer peripheral surface of the male threaded portion 51. As shown in FIGS. 1 and 2, the head portion 53 has a disk shape, has an outer diameter larger than that of the insertion hole 43 of the grommet 40, and has a screw shape as a whole as the screw 50.

As shown in FIGS. 1 and 2, a single groove 54 is formed on the upper surface of the head 53, the groove 54 passing through the axial center of the shaft 52 and having both ends open to the peripheral edge of the head 53. Although not shown, the screw 50 can be rotated by inserting a flat-blade screwdriver or a coin into the groove 54. As shown in FIGS. 1 and 2, for example, the groove portion 54 of the screw 50 passes through the axial center of the shaft portion 52 and both ends are open to the peripheral edge of the head portion 53, so that although not shown, the screw portion 50 It can be molded by using a surface-separating mold, and in that case, a slider or thread cutting is unnecessary. (How to use) Next, the fastener 10 having the above-mentioned configuration
A method of fixing the two panels 20 and 30 in a polymerized manner by using will be described below.

First, each of the two panels 20 and 30 is penetrated,
As shown in FIGS. 1 and 2, the through holes 21 and 31 formed to have a diameter substantially equal to the outer diameter of the leg portion 42 of the grommet 40 are vertically arranged in series so that the two panels 20 and 30 are overlapped with each other. . Then, the leg portions 42 of the grommet 40 are inserted in series into the through holes 21 and 31 of the panels 20 and 30, the flange 41 is brought into contact with the surface of the panel 20 on one side, and the seat portion 46 is formed into the through holes 21. Insert it inside and temporarily fix the grommet 40 to the two panels 20 and 30.

At this time, since the tip ends of the leg portions 42 are tapered, the leg portions 42 can be easily inserted into the through holes 21, 31. Next, the shaft portion 52 of the screw 50 is press-fitted into the insertion hole 43 from the flange 41 side of the insertion hole 43 of the grommet 40, as shown in FIG. The shaft portion 52 is pushed into the insertion hole 43 until the head portion 53 contacts the flange 41 of the grommet 40.

At this time, the shaft portion 52 has the slit 45 of the leg portion 42.
While pushing in, it enters into the insertion hole 43, the diameter of the leg portion 42 expands, the outer peripheral surface of the leg portion 42 adheres to the inner peripheral surfaces of the through holes 21, 31, and the outer peripheral surface of the shaft portion 52 is provided. The male screw portion 51 engages with the female screw portion 44 provided on the inner wall of the insertion hole 43 of the grommet 40, and the leg portion 42 of the screw 50 does not come off from the insertion hole 43 of the grommet 40.

In this way, using the fastener 10,
The two panels 20, 30 can be fixed in a polymerized manner.
On the other hand, in order to separate the two panels 20 and 30 fixed in a superposed manner, insert a flat-blade screwdriver or coin (not shown) into the groove 54 provided in the head 53 of the screw 50, and pull out the screw 50 in the pulling direction. Rotate to the screw 50 shaft 52
Is pulled out from the insertion hole 43 of the grommet 40.

In this state, the leg portion 42 of the grommet 40 is
The diameter can be reduced by the slit 45, and the close contact between the outer peripheral surface of the leg portion 42 and the inner peripheral surface of the through holes 21, 31 is released. Next, holding the flange 41 of the grommet 40,
Is pulled out from the through holes 21 and 31, the two panels 20 and 30 are separated. As described above, the screw 50 described above can be easily rotated with a hand-held coin or the like without holding a tool, so that the screw 50 can be easily removed. (Second Embodiment) On the other hand, regarding the second embodiment of the screw,
It will be described with reference to FIG.

FIG. 4 shows a perspective view of the screw. Book second
The screw 60 of the embodiment is obtained by changing the shape of the head 53 of the screw 50 of the first embodiment described above, and the other members are the same as those of the fastener 10 of the first embodiment. Omit it. The screw 60, as shown in FIG.
On the upper surface of the disk-shaped head 63 provided at the upper end of 62, screw
A pair of rectangular blocks 65, 65 are formed symmetrically spaced apart from each other with respect to the axial center of 60, and a single groove 64 is formed within the interval between both blocks 65. Both ends of the groove 64 are formed. Are open to the periphery of the head 63.

As shown in FIG. 4, each of the rectangular blocks 65 has a rectangular cross section protruding from the upper surface of the head 63 of the screw 50 and is formed integrally with the screw 50 when the screw 50 is formed. . The block 65 is not limited to a rectangular shape, but may be formed in an oval shape or an elliptical shape. Grommet 40 insertion hole
In order to remove the screw 60 engaged with the inside of 43, a slotted screwdriver or a coin (not shown) may be inserted into the groove 64 formed in the space between the pair of rectangular blocks 65, and the screw 50 may be rotated in the extracting direction. . (Third Embodiment) Next, a third embodiment of the screw will be described with reference to FIG.

FIG. 5 shows a perspective view of the screw. Book 3
The screw 70 of the embodiment is obtained by changing the shape of the head portion 53 of the screw 50 of the first embodiment described above, and the other members are the same as those of the fastener 10 of the first embodiment. Omit it. The screw 70, as shown in FIG.
On the upper surface of the disk-shaped head 73 provided at the upper end of 72, screw
A pair of rectangular blocks 75, 75 are formed to face each other with point symmetry with respect to the axis center of 70, and a single groove 74 is formed within the interval between both blocks 75. Both ends of the groove 74 are formed. Are open to the periphery of the head 73.

As shown in FIG. 5, each of the rectangular blocks 75 has a rectangular cross section protruding from the upper surface of the head 73 of the screw 70, and is formed integrally with the screw 70 when the screw 70 is formed. . The block 75 is not limited to a rectangular shape, but may be formed in an oval shape or an elliptical shape. Grommet 40 insertion hole
To remove the screw 70 engaged with the inside of the 43, insert a flat-blade screwdriver or coin into the groove 74 formed in the space between the pair of rectangular blocks 75, and rotate the screw 70 in the removing direction. good. (Fourth Embodiment) Next, a fourth embodiment of the screw will be described with reference to FIG.

FIG. 6 shows a perspective view of the screw. Book 4
The screw 80 of the embodiment is obtained by changing the shape of the head portion 53 of the screw 50 of the first embodiment described above, and the other members are the same as those of the fastener 10 of the first embodiment. Omit it. The screw 80, as shown in FIG.
On the upper surface of the disk-shaped head 83 provided on the upper end of 82, screw
A pair of fan-shaped blocks 85 that are symmetrically spaced apart from each other and are opposed to the axial center of 80 are formed, and a single groove 84 is formed in the interval between both fan-shaped blocks 85. It is open to the periphery.

As shown in FIG. 6, each fan-shaped block 85 has a fan-shaped cross-section protruding from the upper surface of the head 83 of the screw 80, and is formed integrally with the screw 80 when the screw 80 is formed. As shown in FIG. 6, a pair of symmetrical fan-shaped grooves 84 communicating with each other at the center are formed in the space between the pair of fan-shaped blocks 85. It is open to the periphery.

To remove the screw 80 engaged in the insertion hole 43 of the grommet 40, a screwdriver, a coin or the like (not shown) is inserted into the groove 84 formed in the space between the pair of fan-shaped blocks 85, and the screw 80 is inserted. It suffices to rotate in the pulling direction.

[0036]

Since the present invention is configured as described above, it has the following effects. Claim 1
According to the described invention, the following effects can be obtained. That is, according to the invention as set forth in claim 1, not only the mold can be easily manufactured and the manufacturing cost can be reduced, but also the screw, which is familiar to the user, can be used without using a tool such as a Phillips screwdriver. It is possible to provide a removable plastic fastener.

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the following effect is exhibited. That is, according to the second aspect of the present invention, the screw can be easily rotated by inserting a coin or the like into the groove formed in the space between the pair of blocks. Claim 3
According to the described invention, in addition to the effects of the invention described in claim 1 or claim 2, the following effects are exhibited.

That is, according to the invention of claim 3,
Since each block is formed in a symmetrical fan shape around the groove, the groove width at both ends of the groove can be set wide, and a coin or the like can be easily inserted.

[Brief description of the drawings]

FIG. 1 is an exploded sectional view of a fastener.

FIG. 2 is an exploded side view of the fastener.

FIG. 3 is a cross-sectional view showing a usage state of the fastener.

FIG. 4 is a perspective view of a screw according to the second embodiment of the present invention.

FIG. 5 is a perspective view of a screw according to the third embodiment of the present invention.

FIG. 6 is a perspective view of a screw according to the fourth embodiment of the present invention.

[Explanation of symbols]

 10 Fasteners 20,30 Panels 21,31 Through holes 40 Grommets 41 Flange 42 Legs 43 Insertion holes 44 Female threads 45 Slits 46 Seats 50 Screws 51 Male threads 52 Shafts 53 Heads 54 Grooves 60,70,80 Screws 61, 71,81 Male thread 62,72,82 Shaft 63,73,83 Head 64,74,84 Groove 65,75 Square block 85 Fan block

Claims (3)

[Claims] 1. A flange, a leg portion extending from the lower surface of the flange and capable of expanding the outer diameter, an insertion hole axially provided from the upper surface of the flange toward the leg portion, and the insertion hole. A grommet having a female threaded portion provided on the inner wall, and a shaft portion having a male threaded portion which is inserted into the insertion hole of the grommet to expand the diameter of the leg portion and which is provided on the outer peripheral surface to engage the female threaded portion of the insertion hole And a plastic fastener provided with a screw having a head provided on the upper end of the shaft portion, wherein the upper surface of the head of the grommet passes through the shaft center of the shaft portion and both ends are peripheral edges of the head portion. A plastic fastener characterized in that an open groove is formed at the end. 2. The plastic fastener according to claim 1, wherein the groove portion is formed within a space between the pair of blocks protruding from the upper surface of the head portion. 3. The plastic fastener according to claim 2, wherein each block is formed in a fan shape symmetrical about the groove.