JP2001355619A - Clip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the tensile breaking strength of each engaging piece forming an engaging part of a clip, and to reduce the insertion load of the clip by using the flexible material for the engaging piece, and to use polypropylene(PP) capable of improving the workability and lowering the cost. SOLUTION: In this clip for installing a member to be fitted such as a trimming board to a fitting plate such as a door inner panel, an engaging part 12 to be inserted into a circular fitting hole formed in the fitting plate while passing through the surface and the back surface thereof is formed of plural engaging pieces 16 elastically deflectable inward. The cross sectional shape of each engaging piece 16 is set into a shape capable of preventing the secondary moment of inertia at the deflection with the same condition including the area from becoming the maximum value, while maintaining the cross sectional area within a required value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clip used for attaching a trim board to an inner panel of, for example, an automobile door.

[0002]

2. Description of the Related Art Conventionally, a clip of this type is, for example, shown in FIG.
There are those having a structure indicated by 0 to 12. FIG. 10 is a front view showing a conventional clip 60 in a partial cross section, and FIG. 11 is a cross sectional view taken along the line DD in FIG. The clip 60 is an integrally molded product made of synthetic resin, and has a circular mounting hole 42 formed in the inner panel 40 of an automobile door.
And an assembling part 70 attached to a door trim board (not shown). The engaging portion 62 includes a column 64 located at the axis thereof and four engaging pieces 66 positioned outside the column 64.
And Each of these engagement pieces 66 is
Can be elastically bent inward (axial direction), and each outer shape has a slope 68 having a predetermined taper angle.
It has become. A holding portion 69 having a shape in which the outer surface of each engagement piece 66 is dented toward the axial center is formed on the outer periphery of the engagement portion 62 on the base end side. Since the holding portion 69 is located in the mounting hole 42, the insertion state of the engaging portion 62 into the mounting hole 42 is held by a specified holding load.

In using the clip 60, first, the mounting portion 70 is attached to the trim board, and then the engaging portion 62 is inserted into the mounting hole 42 of the panel 40.
Along with this insertion, each engagement piece 66 comes into contact with the inner periphery of the mounting hole 42 and receives a reaction force, and the reaction force causes each engagement piece 66 to bend inward of the engagement portion 62. This bending causes the engaging portion 62
Passes through the mounting hole 42 and the holding portion 69 is
The insertion is completed by being located at. Thus, the engaging portion 62 is held in the mounting hole 42 with the specified holding load as described above. The cross-sectional shape of each of the engagement pieces 66 is
As shown in FIG. 11, each has a fan shape, and the cross-sectional area of each is set to a value that secures a predetermined tensile breaking strength required for each engagement piece 66.

[0004]

By the way, the engaging portion 6
The second moment of area is one factor that determines the ease of flexing of each engagement piece 66 when the 2 is inserted into the mounting hole 42 of the panel 40. As long as the material of the clip 60 and other conditions are the same, the engagement pieces 66 are easily bent by reducing the second moment of area of each engagement piece 66. In order to reduce the second moment of area, FIG.
In the transverse cross-sectional shape, the bending direction of each engagement piece 66, that is, the thickness or the length of the circular arc in the axial direction of the engagement portion 62 is to be reduced.

However, when the above dimensions are reduced, the cross-sectional area of each engaging piece 66 is reduced, and the above-mentioned tensile breaking strength cannot be ensured. The load increases. If the insertion load is too large, the workability when attaching or detaching the clip 60 to or from the panel 40 becomes poor, and when the clip 60 is repeatedly attached and detached, the outer surface of the engaging piece 66 is cut by the edge of the mounting hole 42. It becomes easy to be. As a result, the clip 60 must be formed of an expensive material such as polyacetal (POM) having excellent wear resistance. An object of the present invention is to solve the above-described problem, and an object of the present invention is to make each of the engaging pieces easy to bend while securing the tensile breaking strength of each of the engaging pieces constituting the engaging portion of the clip. An object of the present invention is to reduce the insertion load of the clip, to improve workability and to use polypropylene (PP) or the like which is advantageous in cost.

[0006]

According to the present invention, there is provided a clip which is used for mounting a predetermined member to be mounted on a mounting plate. An engaging portion inserted into a circular mounting hole penetrating the front and back of the mounting plate is constituted by a plurality of engaging pieces that can be elastically bent inward. The cross-sectional shape of each of these engaging pieces, while keeping the area within the required value range, when the other conditions including this area are the same, the secondary moment of area in the above-mentioned bending becomes the maximum value. The shape is set to avoid becoming

By setting the cross-sectional shape of each of the engagement pieces as described above, each of the engagement pieces is easily bent while maintaining the tensile breaking strength of these engagement pieces at a specified value, and the clip of the clip is formed. Insertion load can be reduced.
Therefore, the workability when attaching or detaching the clip to or from the mounting plate is improved, and even when such attachment and detachment are repeated, the outer surface of the engagement piece is not easily scraped off, which is advantageous in cost, such as PP. Clips can be molded from the material.

Further, it is preferable that the cross-sectional shape of each of the engagement pieces is set such that the maximum thickness thereof is deviated from an imaginary straight line indicating the direction of the bending. Further, it is more preferable that the cross-sectional shape of each engagement piece is set to a shape in which the length of a circular arc in contact with the inner periphery of the mounting hole when the area is the same is made as long as possible. In this case, since the contact pressure between each of the engagement pieces and the inner circumference of the mounting hole is dispersed, the outer surface of the engagement piece is less likely to be scraped off.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS. In this embodiment, the present invention is applied to a clip for mounting a trim board of an automobile door. FIG. 1 is a front view showing the appearance of the clip, and FIG. 2 is a plan view showing the appearance of the clip. FIG. As is clear from these drawings, the clip 10 of the present embodiment is also an integrally molded product made of a synthetic resin like the conventional clip 60, and its structure is roughly divided into the engaging portion 12 and the assembly portion 30.

The engaging portion 12 is a portion to be inserted into a circular mounting hole 42 of a door inner panel 40, which will be described later, as an example of a mounting plate. And a plurality of engaging pieces 16.
The support 14 extends from the rigid substrate 13 toward the front end, and an end surface of the support 14 has an arc surface 26.
There is a substantially conical shaped block portion 26 that has become a. The block portion 26 has sufficient rigidity to withstand an impact caused by mutual displacement when the engaging portion 12 is inserted into the mounting hole 42.

FIG. 3 is a structural view showing the cross-sectional shape of the engaging portion 12. FIG. 3 (A) is a cross-sectional view taken along the line AA of FIG. 1, and FIG. FIG. 1 is a cross-sectional view taken along line BB of FIG. 4 is a cross-sectional view in the direction of arrows CC in FIG. 2, and FIG. 5 is a cross-sectional view illustrating a use state of the clip 10. As shown in FIG. 3, the column 14 is composed of two plate-like members 14a, and both upper and lower ends of these plate-like members 14a are connected to the substrate 13 and the block portion 26, respectively. In addition, the two plate-shaped members 14a increase the strength against compression or bending, and include the above-mentioned engaging pieces 16 whose transverse cross-sectional shape has a deformed fan shape as described later, including the individual bending spaces. It is almost L-shaped because it needs to be stored.

There are a total of four engaging pieces 16, which are arranged at substantially equal intervals in the circumferential direction of the engaging portion 12. One end of each engagement piece 16 is connected to the block 2
6 and a connecting portion 16a integral with the substrate 13 at the other end. Therefore, portions other than the coupling portions 16a and 16b of each engagement piece 16 are
When receiving an external load, the engagement portion 12 can be bent inward by the elasticity of the synthetic resin.

The cross-sectional shape of each of the engaging pieces 16 is shown in FIG.
(A) As shown in (B), it has a deformed fan shape, and the area of each differs slightly depending on the position of the engaging portion 12 in the insertion direction. However, the area of any position is set to a value that can secure a predetermined tensile breaking strength required for each engagement piece 16. The cross-sectional shape of each engagement piece 16 is set to a shape in which the second moment of area in the above-described bending is reduced. That is, each of the engagement pieces 16 is a kind of a doubly supported beam. When the bending elastic modulus, the length of the beam, and other conditions are the same, the second moment of area of each of the engagement pieces 16 is reduced. Thus, these engagement pieces 16 can be bent with a smaller load.

FIG. 6 is a schematic diagram showing the cross-sectional shape of the engaging piece 16 in comparison with the conventional engaging piece 66 described above. The cross-sectional area of the engagement piece 16 shown in FIG. 6A is substantially the same as that of the conventional engagement piece 66 shown in FIG. 6B, and the above-mentioned conditions for forming the beam are also substantially the same. And When the respective bending directions are indicated by virtual straight lines S, the engagement pieces 16
In the cross-sectional shape of, the maximum portion of the thickness is deviated from the virtual straight line S, whereas the maximum thickness portion of the engagement piece 66 substantially matches the virtual straight line S. Due to the relationship between the bending direction (virtual straight line S) and the cross-sectional shape, the secondary moment of area of the engaging piece 16 becomes smaller than that of the engaging piece 66.

In addition, since the engaging piece 16 is set to have the above-described cross-sectional shape, even if the cross-sectional shape of the engaging piece 66 is substantially the same as that of the engaging piece 66, the length of the arc can be reduced. L1 and L2 can be set to (L1> L2). Note that the area of the cross-sectional shape of each engagement piece 16 is
Is an important factor in securing the breaking strength against the tensile load applied to the wire, and is set to a specified area calculated based on the required breaking strength. Furthermore, each engagement piece 1
The curvature of the circular arc in the cross-sectional shape of FIG.
As shown in (B), the mounting hole 4 is provided at any part.
The curvature is set to substantially the same value as the curvature of 2. In other words, the center of the arc in each engagement piece 16 is different from each other, except for where the outer diameter of the engagement portion 12 and the inner diameter of the mounting hole 42 match.

Next, the vertical cross-sectional shape of each engagement piece 16 will be described. The outer surface of each engagement piece 16 has a contact angle θ (the outer surface of each engagement piece 16 and the inner peripheral surface of the mounting hole 42 shown in FIG. 5). The angle is an gradually changing surface that changes (gradually decreases) with the insertion of the engagement portion 12. Specifically, the gradually changing surface is formed by the curved surface 20 that draws a large arc along the insertion direction of the engaging portion 12 into the mounting hole 42 of the panel 40. The outer surface of each engaging piece 16 on the base end side of the engaging portion 12 is a holding portion 24 that is recessed in the axial direction of the engaging portion 12. That is, the curved surface 20 of each engagement piece 16
Are continuous over the range from their respective tips to just before the individual holding portions 24.

In each of the engagement pieces 16, a portion from each curved surface 20 to the holding portion 24 is a locking slope 24a. Based on the inclination angle of the locking inclined surface 24a and the rigidity of the engaging piece 16 at the position forming the holding portion 24, the engaging portion 12 is held in a state of being inserted into the mounting hole 42. Is determined (a load that withstands the pulling force on the clip 10). At the base end of the engaging portion 12, there is a dish-shaped stabilizer 28 which greatly expands outward from the substrate 13 integrally. The stabilizer 28 is provided when the engaging portion 12 is inserted into the mounting hole 42. It contacts the surface of panel 40 while being elastically deformed.

The assembling portion 30 is a portion to be attached to the attaching portion 46 of the trim board 44 shown in FIG. 5 as an example of a member to be attached. The assembling portion 30 includes a flange 34 facing the substrate 13 with a small-diameter neck portion 36 interposed therebetween. By positioning the mounting portion 46 of the trim board 44 between the substrate 13 and the flange 34, the mounting portion 30 can be mounted on the trim board 44.

In order to attach the trim board 44 to the panel 40 using the clip 10 configured as described above, first, the assembling portion 30 of the clip 10 is attached to the trim board 44 as described above. In this state, the engaging portion 12 of the clip 10 is inserted into the mounting hole 42 of the panel 40. In the initial stage of this insertion, the curved surface 20 of each engaging piece 16 is attached to the mounting hole 42 as shown in FIG. Contact the inner circumference of This contact start point is located near a point slightly past the coupling portion 16a of each engagement piece 16, that is, near each engagement piece 16 can be bent.

Subsequently, when the engaging portion 12 is inserted,
Each engaging piece 16 receives a reaction force while continuing to contact the inner periphery of the mounting hole 42 along each curved surface 20, and is gradually pushed and bent inward of the engaging portion 12. This state is shown in FIG. 7, and as is clear from FIG. 7, the contact angle θ shown in FIG. 5 starts to gradually decrease from the time when the curved surface 20 comes into contact with the inner periphery of the mounting hole 42, The contact angle θ is 0 degrees. Then, as shown in FIG. 8, the insertion of the engaging portion 12 is completed when the holding portion 24 is located in the mounting hole 42.

As described above, when the engaging portion 12 is inserted into the mounting hole 42, the curved surface 20 of each engaging piece 16 is brought into contact with the inner periphery of the mounting hole 42 at an early point in the insertion stroke. After the contact, each engagement piece 16 is flexed along the curved surface 20 of a large circular arc to positively accelerate the change of the contact angle θ to 0 degree. Moreover, since the cross-sectional shape of each engagement piece 16 is set so as to reduce the second moment of area as described above, it is easy to bend.
Due to these synergistic effects, the insertion load of the engaging portion 12 is suppressed to a small value.

Therefore, the clip 10 is attached to the panel 40.
In addition to improving the workability when attaching or detaching, the friction between the outer surface of each engagement piece 16 and the inner peripheral edge of the mounting hole 42 is small even when such detachment is repeated,
The engagement piece 16 is not easily scraped off. As a result clip 1
For example, PP can be used as the zero material, avoiding expensive POM or the like, and cost can be reduced. Moreover, since the length L1 of the arc of the cross-sectional shape in each engagement piece 16 is large as described above, the engagement portion 12
The contact pressure between each engagement piece 16 and the mounting hole 42 at the time of insertion is dispersed, and the outer surfaces of these engagement pieces 16 are less likely to be scraped off.

FIG. 9 is a structural view showing a modified example of the cross-sectional shape of the engaging portion 12. As shown in FIG. In this drawing, two plate-like members 14 a constituting the support column 14 are connected to each other near the center of the engaging portion 12. That is, in FIG. 9A, the plate members 14a are connected to each other at one point, and in FIG. 9B, the plate members 14a are connected to each other at two points. This further increases the strength of the column 14 against compression or bending.

In the above embodiment, the clip 1
The second section moment is reduced by the cross-sectional shape of each of the engagement pieces 16 constituting the zero-engagement portion 12, and the engagement portion 12 is inserted by the synergistic effect of the large arc-shaped curved surface 20 in the vertical cross-section shape. Although the load is suppressed to a small value, it is possible to make each engagement piece 16 sufficiently flexible by only one of the measures.

[Brief description of the drawings]

FIG. 1 is a front view showing the appearance of a clip.

FIG. 2 is a plan view showing the appearance of the clip.

FIG. 3 is a configuration diagram showing a cross-sectional shape of an engaging portion of the clip.

FIG. 4 is a sectional view taken in the direction of arrows CC in FIG. 2;

FIG. 5 is a sectional view showing a use state of the clip.

FIG. 6 is a schematic diagram illustrating a cross-sectional shape of an engagement piece in comparison with a conventional technique.

FIG. 7 is a cross-sectional view illustrating a state during insertion of the clip.

FIG. 8 is a cross-sectional view illustrating a completed state of insertion of the clip.

FIG. 9 is a configuration diagram illustrating a modified example of a cross-sectional shape of an engagement portion.

FIG. 10 is a front view showing a conventional clip in a partial cross section.

FIG. 11 is a sectional view taken in the direction of arrows DD in FIG. 10;

FIG. 12 is a sectional view showing a conventional clip insertion state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Clip 12 Engagement part 16 Engagement piece 40 Panel (mounting plate) 42 Mounting hole 44 Trim board (member to be mounted)

Claims (3)

[Claims] 1. A clip used for mounting a predetermined member to be mounted on a mounting plate, wherein an engaging portion inserted into a circular mounting hole formed through the front and back of the mounting plate. , While being constituted by a plurality of engagement pieces that can be elastically bent inward, the cross-sectional shape of each of these engagement pieces, while maintaining the area thereof within the required value range, A clip set in a shape that avoids the maximum secondary moment of area in the above-mentioned bending when other conditions including this area are the same. 2. The clip according to claim 1, wherein a cross-sectional shape of each of said engagement pieces is such that a maximum portion of a thickness thereof is deviated from an imaginary straight line indicating a direction of said bending. Clip set to. 3. The clip according to claim 1, wherein a cross-sectional shape of each of said engaging pieces is a length of an arc which is in contact with an inner periphery of said mounting hole when an area thereof is the same. A clip that is as large as possible.