JP7518059B2 - Plastic parts with insert nuts - Google Patents

Description

This disclosure relates to a plastic part with an insert nut.

A structure in which an insert nut is embedded in a cylindrical resin molded product is known (see Patent Document 1). In this structure, a convex portion on the holder into which the insert nut is inserted restricts the rotation of the insert nut relative to the resin molded product when the bolt is tightened.

JP 2019-217707 A

In the above-mentioned structure, when the bolt is tightened into the insert nut, the part of the resin molded product that comes into contact with the protrusion is significantly deformed. This deformation causes the rotation of the insert nut to no longer be restricted, which can lead to the insert nut spinning freely and the torque required to tighten the bolt cannot be obtained.

One aspect of the present disclosure aims to provide a plastic part with an insert nut that can prevent the insert nut from spinning freely.

One aspect of the present disclosure is a resin part with an insert nut, which includes an insert nut and a resin holding part that holds the insert nut. The holding part has a main body, a cylindrical embedding part that protrudes from the main body and in which the insert nut is embedded, and at least one plate-shaped rib that is provided across the embedding part and the main body. The insert nut has a restricting part that restricts the rotation of the insert nut relative to the embedding part.

At least one rib has a first end extending along the axial direction of the embedded portion on the outer peripheral surface of the embedded portion, and a second end extending from the first end toward the radially outer side of the embedded portion on the surface of the body from which the embedded portion protrudes. When viewed from the axial direction of the insert nut, the extension direction of the second end is inclined toward the side where the bolt is tightened to the insert nut, relative to the radial direction of the insert nut at the first end.

With this configuration, the rib connecting the embedded portion and the main body improves the rigidity of the embedded portion. In addition, the second end of the rib is inclined toward the bolt tightening side relative to the radial direction of the insert nut, which suppresses deformation of the embedded portion when the bolt is tightened. As a result, it is possible to suppress free rotation of the insert nut.

In one aspect of the present disclosure, the insert nut has multiple flat outer surfaces perpendicular to the radial direction of the insert nut. The retaining portion has multiple ribs arranged on the outside of each of the multiple outer surfaces as at least one rib. A first end of each of the multiple ribs may overlap with a widthwise center of the multiple outer surfaces in the radial direction of the insert nut. With this configuration, the first end is located near the widthwise center of the outer surfaces where stress is likely to occur when the bolt is tightened, which promotes the effect of suppressing deformation of the embedded portion when the bolt is tightened.

In one aspect of the present disclosure, the outer shape of the embedded portion when viewed from the axial direction of the insert nut may be circular. This configuration makes it easier to mold the embedded portion.

In one aspect of the present disclosure, the insert nut may have a threaded portion having a thread groove. At least one rib may overlap the threaded portion in the radial direction of the insert nut. With this configuration, the rib is disposed on the outside of the threaded portion where stress is likely to occur when the bolt is tightened, which promotes the effect of suppressing deformation of the embedded portion when the bolt is tightened.

FIG. 1 is a schematic cross-sectional view showing a state in which a resin part with an insert nut is used according to an embodiment. 2A is a schematic perspective view of the resin part with an insert nut of FIG. 1, and FIG. 2B is a schematic cross-sectional end view taken along line IIB-IIB of FIG. 2A. FIG. 3 is a schematic plan view of the resin part with the insert nut of FIG. 1. FIG. 4A, 4B, 4C, and 4D are schematic plan views of a resin part with an insert nut in an embodiment different from that in FIG. 3. 5A, 5B, and 5C are schematic perspective views of a resin part with an insert nut in an embodiment different from that in FIG. 2A. FIG. 6 is a schematic perspective view of a resin part with an insert nut in an embodiment different from that in FIG. 2A.

Hereinafter, embodiments to which the present disclosure is applied will be described with reference to the drawings.
[1. First embodiment]
[1-1. Configuration]
The resin part with an insert nut 1 shown in FIG.

In the resin part 1 with insert nut, the fastening part is fastened to the holding part 3 by tightening the bolt 11 to the insert nut 2. In FIG. 1, a plate-shaped bracket 14 is attached to the holding part 3 via a bush 13 as an example of a fastening part. The bracket 14 is sandwiched between the bush 13 in the thickness direction. The bush 13 is fastened to the insert nut 2 together with the collar 12 by the bolt 11.

<Insert nut>
The insert nut 2 is made of metal. As shown in Figures 2A and 2B, the insert nut 2 has a screw-in portion 21 and a leg portion 22.

The screw-threaded portion 21 has a hollow portion with a thread groove into which the bolt 11 screws. The screw-threaded portion 21 is axially press-fitted into the embedded portion 32 of the retaining portion 3. The outer peripheral surface of the screw-threaded portion 21 is in contact with the inner peripheral surface of the embedded portion 32.

When viewed from the axial direction, the screw-in portion 21 has a rectangular outer shape. Therefore, the screw-in portion 21 has a first corner 211, a second corner 212, a third corner 213, and a fourth corner 214. Each of the four corners 211, 212, 213, and 214 is a restricting portion that restricts the rotation of the insert nut 2 relative to the embedded portion 32.

The leg portion 22 is connected to the threaded portion 21 in the axial direction of the insert nut 2. The leg portion 22 has a hollow portion into which the tip of the bolt 11 that passes through the threaded portion 21 is inserted. The outer peripheral surface of the leg portion 22 is in contact with the inner peripheral surface of the embedded portion 32.

<Holding part>
The holding portion 3 is a resin member that holds the insert nut 2. The holding portion 3 has a main body 31, an embedded portion 32, a first rib 33, a second rib 34, a third rib 35, and a fourth rib 36.

＜Main unit＞
The main body 31 is a portion that constitutes a base from which the embedded portion 32 protrudes. In this embodiment, the main body 31 is a plate-shaped member, but the main body 31 is not limited to being plate-shaped. The main body 31 may be a part of a functional component molded from resin.

In this embodiment, the insert nut 2 does not reach the main body 31. However, the end of the insert nut 2 may be disposed inside the main body 31 or may penetrate the main body 31.

<Embedded part>
The embedding portion 32 is a cylindrical portion that protrudes from the main body 31 and in which the insert nut 2 is embedded.

When viewed from the axial direction of the insert nut 2, the outer shape of the embedded portion 32 is circular. In other words, the embedded portion 32 is cylindrical. The hollow portion of the embedded portion 32 is a square prism shape that matches the outer shape of the insert nut 2.

The central axis of the embedded portion 32 coincides with the central axis of the insert nut 2. The direction in which the embedded portion 32 protrudes from the body 31 (i.e., the upward direction in FIG. 2B) is opposite to the direction in which the bolt 11 is inserted into the insert nut 2 (i.e., the downward direction in FIG. 2B).

In this embodiment, the embedded portion 32 is provided on the first surface 31A of the main body 31, which is the side into which the bolt 11 is inserted (i.e., the side into which the fastening component is attached). In addition, the embedded portion 32 does not protrude from the second surface 31B, which is the opposite side to the first surface 31A.

<Rib>
The first rib 33 , the second rib 34 , the third rib 35 , and the fourth rib 36 are each a plate-like portion provided across the embedded portion 32 and the main body 31 .

The first rib 33, the second rib 34, the third rib 35, and the fourth rib 36 each overlap at least partially with the screw-threaded portion 21 of the insert nut 2 in the radial direction of the insert nut 2. In other words, the screw-threaded portion 21 of the insert nut 2 is disposed in the same position as the first rib 33, the second rib 34, the third rib 35, and the fourth rib 36 in the axial direction of the insert nut 2.

The thickness direction of the first rib 33 is perpendicular to the axial direction of the insert nut 2. In other words, the plate surface of the first rib 33 is parallel to the axial direction of the insert nut 2. The planar shape of the first rib 33 (i.e., the shape when viewed from the thickness direction) is trapezoidal.

The first rib 33 has a first end 33A, a second end 33B, a third end 33C, and a fourth end 33D. The first end 33A, the second end 33B, the third end 33C, and the fourth end 33D are each formed by an end surface of the first rib 33.

The first end 33A is a connection portion of the first rib 33 with the outer peripheral surface of the embedded portion 32. The first end 33A extends along the axial direction of the embedded portion 32 on the outer peripheral surface of the embedded portion 32. The first end 33A extends from the first surface 31A of the main body 31 from which the embedded portion 32 protrudes, to the protruding end of the embedded portion 32. The first end 33A constitutes a portion that corresponds to a leg of the trapezoid that is perpendicular to the upper and lower bases (i.e. parallel to the height direction).

The second end 33B is the connection portion of the first rib 33 with the main body 31. The second end 33B extends from the first end 33A (i.e., the outer peripheral surface of the embedded portion 32) on the first surface 31A of the main body 31 toward the radially outer side of the embedded portion 32. The second end 33B is connected to the first end 33A on the first surface 31A of the main body 31. The second end 33B forms a portion that corresponds to the lower base of the trapezoid.

The third end 33C extends parallel to the second end 33B at a position separated from the second end 33B in the axial direction of the insert nut 2. The third end 33C is shorter than the second end 33B. The third end 33C is connected to the first end 33A at the protruding end of the embedded portion 32. The third end 33C forms a portion that corresponds to the upper base of the trapezoid.

The fourth end 33D connects the second end 33B and the third end 33C on the opposite side to the first end 33A. The fourth end 33D faces the first end 33A. The fourth end 33D forms a part that corresponds to a leg of the trapezoid that is inclined in the height direction.

As shown in FIG. 3, the insert nut 2 has a flat first outer surface 221, a second outer surface 222, a third outer surface 223, and a fourth outer surface 224 that are perpendicular to the radial direction of the insert nut 2. These outer surfaces 221, 222, 223, and 224 form the outer peripheral surface of the screw-in portion 21 of the insert nut 2.

The first end 33A of the first rib 33 overlaps with the widthwise center of the first outer surface 221 in the radial direction of the insert nut 2. In other words, the first rib 33 is positioned on the radial outside of the insert nut 2 on the first outer surface 221.

Here, the "widthwise center of the outer surface" refers to the area closer to the widthwise centerline P than both ends of the outer surface in the circumferential direction of the insert nut 2 (i.e., the first corner 211 and the second corner 212 in the case of the first outer surface 221). The widthwise centerline P is the intersection line between the outer surface and an imaginary plane S that includes the central axis O of the insert nut 2 and is perpendicular to the outer surface.

When viewed from the axial direction of the insert nut 2, the extension direction E (i.e., the longitudinal direction) of the second end 33B of the first rib 33 is inclined toward the side where the bolt 11 is tightened to the insert nut 2 (i.e., the rotation direction D when the bolt 11 is tightened) with respect to the radial direction of the insert nut 2 at the first end 33A (i.e., the starting point of the second end 33B) (i.e., the direction from the central axis of the insert nut 2 toward the first end 33A).

In other words, the first rib 33 is formed by rotating the tip of a rib extending from the first end 33A along the radial direction of the insert nut 2 in the fastening rotation direction D with the first end 33A as the central axis.

In FIG. 3, the radial direction of the insert nut 2 at the first end 33A is parallel to the imaginary plane S and perpendicular to the first outer surface 221.

In the embodiment shown in FIG. 3, the inclination angle θ of the second end 33B with respect to the radial direction of the insert nut 2 is approximately 45°. The length of the second end 33B is approximately the same as the outer radius of the embedded portion 32. In addition, the width of the second end 33B (i.e., the thickness of the first rib 33) is smaller than the length of the second end 33B.

The second rib 34, the third rib 35, and the fourth rib 36 have the same shape as the first rib 33. That is, the second rib 34, the third rib 35, and the fourth rib 36 each have the same first end 33A, second end 33B, third end 33C, and fourth end 33D as the first rib 33.

The first rib 33, the second rib 34, the third rib 35, and the fourth rib 36 are arranged on the outside of the first outer surface 221, the second outer surface 222, the third outer surface 223, and the fourth outer surface 224, respectively, and are arranged at equal intervals in the radial direction of the insert nut 2.

The second rib 34 is positioned at a position offset by 90° from the first rib 33 along the fastening rotation direction D. The first end 33A of the second rib 34 overlaps with the widthwise center of the second outer surface 222 in the radial direction of the insert nut 2. In addition, when viewed from the axial direction of the insert nut 2, the extension direction of the second end 33B of the second rib 34 is inclined toward the fastening rotation direction D with respect to the radial direction of the insert nut 2 at the first end 33A.

The third rib 35 is positioned at a position offset by 90° from the second rib 34 along the fastening rotation direction D. The first end 33A of the third rib 35 overlaps with the widthwise center of the third outer surface 223 in the radial direction of the insert nut 2. In addition, when viewed from the axial direction of the insert nut 2, the extension direction of the second end 33B of the third rib 35 is inclined toward the fastening rotation direction D with respect to the radial direction of the insert nut 2 at the first end 33A.

The fourth rib 36 is positioned at a position offset by 90° from the third rib 35 along the fastening rotation direction D. The first end 33A of the fourth rib 36 overlaps with the widthwise center of the fourth outer surface 224 in the radial direction of the insert nut 2. In addition, when viewed from the axial direction of the insert nut 2, the extension direction of the second end 33B of the fourth rib 36 is inclined toward the fastening rotation direction D with respect to the radial direction of the insert nut 2 at the first end 33A.

As shown in Figures 4A and 4B, the inclination angle of the second end 33B of each rib relative to the radial direction of the insert nut 2 can be set arbitrarily. In the example of Figure 4A, the inclination angle of the second end 33B of each rib relative to the radial direction of the insert nut 2 is smaller than 45°. In the example of Figure 4B, the inclination angle of the second end 33B of each rib relative to the radial direction of the insert nut 2 is larger than 45°.

As shown in Figures 4C and 4D, the length of the second end 33B of each rib can also be set arbitrarily. In the example of Figures 4C and 4D, the length of the second end 33B of each rib is smaller than the outer radius of the embedded portion 32.

[1-2. Effects]
According to the embodiment described above in detail, the following effects can be obtained.
(1a) The rigidity of the embedded portion 32 is improved by the ribs 33, 34, 35, and 36 that connect the embedded portion 32 and the main body 31. In addition, the second ends 33B of the ribs 33, 34, 35, and 36 are inclined toward the side where the bolt 11 is tightened relative to the radial direction of the insert nut 2, thereby suppressing deformation of the embedded portion 32 when the bolt is tightened. As a result, the slippage of the insert nut 2 can be suppressed.

(1b) The first end 33A overlaps with the center of the width of the outer side surfaces 221, 222, 223, and 224 in the radial direction of the insert nut 2, so that the first end 33A is located near the center of the width of the outer side surfaces 221, 222, 223, and 224 where stress is likely to occur when the bolt is tightened. As a result, the effect of suppressing deformation of the embedded portion 32 when the bolt is tightened is promoted.

(1c) The outer shape of the embedded portion 32 when viewed from the axial direction of the insert nut 2 is circular, which makes it easy to mold the embedded portion 32.

(1d) The ribs 33, 34, 35, and 36 are arranged on the outside of the threaded portion 21, where stress is likely to occur when the bolt is tightened, which helps to suppress deformation of the embedded portion 32 when the bolt is tightened.

2. Other embodiments
Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take various forms.

(2a) In the resin part with insert nut of the above embodiment, as shown in FIG. 5A, the embedded portion 32 may penetrate the main body 31. In other words, the embedded portion 32 may protrude from both the first surface 31A and the second surface 31B of the main body 31. In this embodiment, the insert nut 2 penetrates the main body 31 together with the embedded portion 32.

When the embedded portion 32 penetrates the main body 31 in this manner, ribs may be provided on both sides of the embedded portion 32 sandwiching the main body 31, as shown in FIG. 5B. That is, the retaining portion 3 may have, in addition to the ribs 33, 34, 35, and 36 arranged on the first surface 31A on the side where the bolt 11 is inserted, an additional rib 37 arranged on the second surface 31B opposite the first surface 31A. The additional rib 37 has the same shape as the ribs 33, 34, 35, and 36.

In addition, when the embedded portion 32 penetrates the main body 31, as shown in FIG. 5C, an additional rib 37 may be provided on the second surface 31B, and no rib may be provided on the first surface 31A on the side where the bolt 11 is inserted.

(2b) In the resin part with insert nut of the above embodiment, as shown in FIG. 6, the embedded portion 32 may protrude only from the second surface 31B of the main body 31, which is opposite to the first surface 31A on the side where the bolt 11 is inserted (i.e., the side where the fastening part is attached).

In this embodiment, the insert nut 2 is inserted into an opening in the body 31 that communicates with the hollow portion of the embedding portion 32. The ribs 33, 34, 35, and 36 are disposed on the second surface 31B.

(2c) In the resin part with an insert nut of the above embodiment, the outer shape of the insert nut viewed from the axial direction does not necessarily have to be polygonal. For example, the outer shape of the insert nut viewed from the axial direction may be circular. In this case, for example, a convex portion protruding from the outer peripheral surface of the insert nut is provided as a restricting portion that restricts the rotation of the insert nut.

(2d) In the resin part with an insert nut of the above embodiment, the outer shape of the embedded portion when viewed from the axial direction of the insert nut does not necessarily have to be circular. For example, the outer shape of the embedded portion when viewed from the axial direction of the insert nut may be polygonal.

(2e) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. In addition, part of the configuration of the above embodiments may be omitted. In addition, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. All aspects included in the technical idea identified from the wording of the claims are embodiments of the present disclosure.

1 ... resin part with insert nut, 2 ... insert nut, 3 ... holding part,
11 ... bolt, 12 ... collar, 13 ... bush, 14 ... bracket, 21 ... screw-fitting portion,
22: leg portion, 31: main body, 31A: first surface, 31B: second surface, 32: embedded portion,
33: first rib; 33A: first end; 33B: second end; 33C: third end;
33D...fourth end portion, 34...second rib, 35...third rib, 36...fourth rib,
37: additional rib, 211: first corner portion, 212: second corner portion, 213: third corner portion,
214... Fourth corner, 221... First outer surface, 222... Second outer surface, 223... Third outer surface,
224...Fourth outer surface.

Claims (4)

Insert nut,
A resin holding portion that holds the insert nut;
Equipped with
The holding portion is
The main body,
A cylindrical embedding portion protruding from the main body and having the insert nut embedded therein;
At least one plate-shaped rib provided across the embedded portion and the main body;
having
The insert nut has a regulating portion that regulates rotation of the insert nut relative to the embedded portion,
The at least one rib is
a first end portion extending along an axial direction of the embedded portion on an outer peripheral surface of the embedded portion;
a second end portion extending from the first end portion toward a radially outer side of the embedded portion on a surface of the main body from which the embedded portion protrudes;
having
When viewed from the axial direction of the insert nut, the extension direction of the second end is inclined toward the side where the bolt is tightened to the insert nut with respect to the radial direction of the insert nut at the first end. A resin part with an insert nut. The resin part with an insert nut according to claim 1,
The insert nut has a plurality of flat outer surfaces perpendicular to a radial direction of the insert nut,
The holding portion has a plurality of ribs arranged on the outer sides of the plurality of outer surfaces as the at least one rib,
A resin part with an insert nut, wherein the first end of each of the plurality of ribs overlaps with a widthwise center portion of the plurality of outer surfaces in a radial direction of the insert nut. The resin part with the insert nut according to claim 1 or 2,
The resin part with an insert nut, wherein the outer shape of the embedded portion when viewed from the axial direction of the insert nut is circular. The resin part with an insert nut according to any one of claims 1 to 3,
The insert nut has a screw portion provided with a screw groove,
A resin part with an insert nut, wherein the at least one rib overlaps with the threaded portion in a radial direction of the insert nut.

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