JP2002106621A - Bound bumper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bound bumper used at a position where it comes into contact with an axle and capable of preventing its rupture and prolonging its service life by using foaming urethane in a bumper member to hold a small spring constant at an initial stage of compression-deformation and obtain a large spring constant at the time of compression-deformation exceeding a fixed amount. SOLUTION: This bound bumper A consists of the bumper member 1 and a holding fitting 2 holding its terminal part 11. The bumper member 1 composed of the terminal part 11 and a main body part 12 continuous with the terminal part is integrally formed like a substantially square column when viewed in a plan by foaming urethane. The holding fitting 2 is provided with a substantially square cuplike part 20 in which the terminal part 11 of the bumper member 1 is fitted and engaged, and expansion receive parts 25, 25 expanding outward, obliquely, and gradually are extended and provided on both side walls 21a, 21a opposing mutually on one side of the cuplike part 20 to receive side faces 12a, 12a of the bumper member 1 expanding outward at the time of compression-deformation in order to prevent excessive expansion-deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle bound bumper.

[0002]

2. Description of the Related Art A bound bumper used in a vehicle suspension or the like is mainly used to reduce a shock at the time of bounce. As an elastic material of the bumper member of the bound bumper, a rubber material having elasticity and excellent breaking strength has been generally used.

As shown in FIG. 10, the bound bumper generally has a cup-shaped holding member (101) in which a base end (111) of a bumper member (101) integrally formed of a rubber material is opened downward. 102), and is engaged and held by a locking piece (124) provided on the side wall (121) so as not to be pulled out, and the holding bracket (102) is mainly fixed downward to the vehicle body. used.

When the bumper member (101) is made of a rubber material, there is a problem that the spring constant in the initial stage where the displacement is relatively small becomes too large.

[0005] This point will be described with reference to Fig. 11 showing the load-deflection characteristics of a bound bumper using a rubber material.

As a characteristic required for this type of bound bumper, in a region where the displacement of the bound bumper is relatively small, a characteristic having a small spring constant is required to absorb an impact from a road surface, and a region where the displacement is relatively large is required. In this case, a large spring constant is required so that the vehicle body and the suspension do not approach each other excessively or over a certain amount.

However, when a rubber material is used, as shown in FIG. 11, the amount of deflection is small (the spring constant is large) in the initial state of the load-deflection characteristic, that is, in the range where the load is relatively low. There is a problem that the impact is easily transmitted to the vehicle body via the bound bumper, and the quietness of the vehicle is reduced.

Therefore, in order to solve the above-mentioned problems, it has been proposed to use a foamed urethane foam material having a small spring constant and a larger amount of deflection in an initial state of load-deflection characteristics than a rubber material in order to solve the above problems. ing.

However, when the urethane foam is used as the bumper member, the amount of deflection in the initial state of the load-deflection characteristic is relatively large, and a large bending deformation is exhibited even with a relatively small load (a chain line in FIG. 11). However, similar to the case of the bumper member made of a rubber material shown in FIG. 10, when the base end portion is fitted to and engaged with the cup-shaped holding fitting, when the compression deformation of a large load is performed, This bulges greatly (chain line in FIG. 10), and this bulge is strongly pressed against the edge of the side wall of the holding bracket, and as a result of this repetition, breakage occurs at this part, shortening the service life of the holder. Would be.

In particular, in the case where a bumper member made of urethane foam is used at a position where the bumper member is in contact with a substantially horizontal columnar member, the front end surface of the bumper member is a cylindrical member such as the axle. When it is compressed and deformed in contact with the cylindrical member, it does not expand much in the extending direction of the cylindrical member, but expands more than usual in both sides of the cylindrical member. The edge is strongly pressed, and this is repeated, and the above-mentioned problem of the occurrence of breakage becomes significant.

The present invention has been made in view of the above, and has been made in consideration of the above-described problems in the case where urethane foam is used as a bound bumper suitably used at a position where it contacts a cylindrical member such as an axle, in particular, as a bumper member. The present invention provides a bound bumper that is free from breakage, exhibits a large spring constant when a certain amount of bending occurs, and can extend the life.

[0012]

A bound bumper according to the present invention is a bound bumper comprising a bumper member made of an elastic material, and a holding fitting for holding a base end of the bumper member, wherein the bumper member comprises: A base end portion and a main body portion continuous with the base end portion are integrally formed of urethane foam into a substantially square columnar shape in a plane, and the holding metal fitting has a base end portion of the bumper member fitted and engaged. A quadrangular cup-shaped portion is provided, and an extension receiving portion gradually and obliquely expanding outward extends from one of the opposite side walls of the cup-shaped portion.

[0013] The bound bumper is mounted on the vehicle body such that, at a position where it contacts a cylindrical member such as an axle, the side of the side wall on which the four-round expansion receiving portion of the holding bracket is formed is positioned parallel to the cylindrical member. Attach and use.

In this use, when a bounce occurs,
The cylindrical member abuts against the tip end surface of the bumper member and a load is applied to compress the bumper member.The urethane foam has a spring constant smaller than that of the rubber material. It shows larger flexural deformation than a rubber material with a small load, and provides good shock absorption. Further, when a large load of a certain value or more is applied and the bumper member is largely compressed and deformed,
The side surface of the main body portion, particularly the side surface along the extending direction of the circular member is greatly swelled and deformed outward, but the bulged portion of this side surface comes into contact with the inner side surface of the oblique expansion receiving portion of the side wall. Exhibits a large spring constant and suppresses excessive bulging deformation. Moreover, the bulging portion is not strongly pressed against the edge of the side wall of the holding fitting, so that the occurrence of breakage from the abutting portion can be prevented.

In the above-described bound bumper, the main body of the bumper member has a protruding shape in which a side surface on a side corresponding to the extension receiving portion of the holding metal has a gap between the side and the extension receiving portion. It is preferable that the side projection is provided so as to come into contact with the inner side surface of the expansion receiving portion at the time of compressive deformation of an amount or more.

That is, in this case, since there is a gap between the side projection of the bumper member and the expansion receiving portion of the holding member, the bulging side projection is initially formed at the initial stage of the compression deformation of the bumper member. By allowing for a margin for compressive deformation before filling the gap and contacting the expansion receiving portion of the holding bracket, the spring constant in the initial stage of the bending deformation can be kept small, and the impact of a relatively small load can be absorbed. . In addition, when the bumper member undergoes a certain amount of compressive deformation, the side bulging portion abuts on the expansion receiving surface, so that excessive bulging deformation can be suppressed as described above.

From the viewpoint of the above-mentioned effects, it is preferable that the gap between the side protruding portion of the bumper member and the expansion receiving portion of the holding fitting has a gap of 1 to 5 mm.

In the above-mentioned bound bumper, the tip end surface of the bumper member has a concave shape having a curvature axis in one of the vertical and horizontal directions, and a side surface parallel to the curvature axis of the concave shape has an outwardly projecting shape. This makes it possible for the tip end surface of the bumper member to abut against a columnar member such as an axle without displacement, stabilizing the abutting state and extending along the extending direction of the circular member during compression deformation. Both side surfaces swell and deform substantially evenly, and there is no possibility that one side surface is excessively strongly pressed against the expansion receiving portion.

Further, it is preferable that a flange-like edge bent outward in a direction away from the bumper member is provided at an end edge of the expansion receiving portion of the holding fitting. This allows
Even if the side-projecting portion is greatly swelled and deformed, the swelling portion is not strongly pressed by the cornered edge, so that the occurrence of breakage can be reliably prevented.

It is preferable that a flange-like edge bent outward in a direction away from the bumper member is provided also at an edge of the other opposite side wall of the holding metal, and the bumper on the side corresponding to the side wall is provided. Even if the main body side surface of the member swells and deforms, the occurrence of breakage due to being pressed against the side wall edge can be prevented.

The expansion receiving portion of the holding fitting has an inclination in the range of 30 ° to 60 ° with respect to the bumper axis, which suppresses the bulging deformation of the side-projecting portion of the bumper member and the restoring action. Above.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the embodiments shown in the drawings.

1 to 9 show an embodiment of the bound bumper of the present invention. FIG. 1 is a longitudinal sectional view of the bound bumper, FIG. 2 is a bottom view of the bound bumper, and FIG. It is sectional drawing in the X3-X3 line | wire of FIG. 1 of a bumper. 4 is a front view of the bumper member of the bound bumper, FIG. 5 is a plan view of the bumper member, and FIG. 6 is a cross-sectional view of the bumper member taken along line X6-X6 in FIG.
7 is a front view of a half vertical section of a holding bracket of the bound bumper, FIG. 8 is a bottom view of the holding bracket, and FIG. 9 is a cross-sectional view of the holding bracket taken along line X9-X9 in FIG.

The bound bumper (A) of this embodiment is
For example, between the car body and the suspension,
In particular, it shows a member that is disposed and used at a position in contact with a cylindrical member such as an axle when a bounce occurs. When a member on the suspension side approaches the vehicle body due to the bouncing of the vehicle body, a cylindrical member such as an axle ( B) comes into contact with the front end surface of the bumper to perform a buffering action.

In this bound bumper (A), a base end (11) and a main part (12) continuously projecting from the base end (11) have a substantially square columnar shape made of urethane foam as an elastic material. A bumper member (1) integrally formed with
And a holding bracket (2) for holding a base end (11) of the bumper member (1).

An example of the shape of the bumper member (1) is shown in FIGS. As shown in the figure, the bumper member (1) has an engagement groove (13) formed in a substantially rectangular base end portion (11) held by the holding metal fitting (2), for example, in a substantially rectangular base end portion (11). Is formed. The main body (12) continuously projecting downward from the base end (11)
One of four side surfaces (12a), (12a), (12b), and (12b), for example, opposing side surfaces (12a) and (12a) on the long side
And a tapered surface (14a) inclined continuously outward from the base end portion (11) and a tapered surface (14b) gradually inclined inward from the tapered surface (14a). It has a shape and is wider than the base end (11). (15) shows the side projection. The other side surface (12b) (12b) on the short side has a tapered shape that is gently inclined inward as it is from the base end (11). As a result, the main body (12) has a truncated pyramid shape (reverse trapezoidal cross section) toward the lower end as a whole.

In the case of the bumper member (1) shown in the figure, a concave groove (16) is formed in the side surface (12a) (12a) of the overhanging shape in order to adjust the elasticity and the like in the main body (12). In addition, a through hole (17) is formed inside. Since these are for adjusting the elastic characteristics and the like of the bumper member (1), various modifications are possible. For example, the concave groove (16) and the through hole (17) may not be formed.

The distal end surface of the main body (12) has a concave receiving surface (C) whose curvature axis is perpendicular to the plane of FIG. 1, that is, parallel to the overhanging side surface (12a). 18) is formed. This concave receiving surface (18)
Since the bound bumper (A) is disposed and used at a position where it contacts the columnar member (B) such as an axle, as described above, the front end surface of the bumper member (1) is used as the columnar member (B).
It is formed in order to make it surely contact.

On the other hand, the holding bracket (2) is shown in FIGS.
As shown in the figure, the base end (11) of the bumper member (1)
Has a cup-shaped portion (20) having a substantially rectangular shape (substantially rectangular in the figure) corresponding to the base end portion (11) and opening downward so that the base portion (11) is fitted and engaged. The top surface portion (22) of the cup-shaped portion (20) is integrally fixed to the mounting bracket (3) having a substantially rectangular plane at four welding positions (23) by means of spot welding or the like. It is composed. The bracket (3) has a long rectangular plate shape, and has a pair of bolt holes (31) formed near both ends in the longitudinal direction, and a bolt or the like is inserted into each bolt hole (31) to insert a vehicle body (not shown). ).

Each of the four side walls (21) of the cup-shaped portion (20)
a) At (21a), (21b) and (21b), in order to prevent the bumper member (1) fitted inside from coming off,
Locking pieces (24) are formed at one or a plurality of locations by cutting and raising inward, and are formed so as to lock into the engaging grooves (13) of the base end (11) of the bumper member (1). Have been.

Opposite side walls on one of the four side walls of the cup-shaped portion (20), particularly on the long side corresponding to the side surfaces (12a) and (12a) of the bumper member (1) having a projecting shape. (21a) The expansion receiving portion (2a) which gradually and obliquely expands outward as the distance from the side wall increases.
5) (25) is integrally extended, and formed so that the protruding portions (15) of the side surfaces (12a) and (12a) abut when a certain amount or more of the bumper member (1) is compressed and deformed. Thereby, excessive bending deformation of the bumper member (1) can be prevented.

The expansion receiving portion (25) has a slight gap (26) between the side protruding portion (15) of the bumper member (1) and the tapered surface (14a) on the base end (11) side.
And extends slightly outward from the tapered surface (14a).

The inclination of the expansion receiving portion (25) is set in an angle range of 30 ° to 60 ° with respect to the bumper axis, so that a moderate bulge such as a side projecting portion (15) of the bumper member (1) can be obtained. It is preferable because deformation is allowed and excessive bulging deformation can be suppressed. From such an effect, the angle range is more preferably 30 ° to 50 °. The tapered surface (14) of the side projection (15) of the bumper member (1)
a) is a tilt angle corresponding to this.

The interval (S) of the gap (26) is
In the initial stage of the compressive deformation of the bumper member (1), 1 to 5 mm is preferable from the viewpoint of keeping the spring constant small and suppressing excessive bulging deformation at the time of compressive deformation of a certain amount or more. Preferably it is 2 to 4 mm. Further, the length (L) of the gap (26) in the extending direction is preferably 6 to 12 mm, more preferably 6 to 12 mm, from the viewpoint of suppressing the swelling deformation of the bumper member (1) and preventing the breakage by pressing. Is 8 to 10 mm.

The gap (26) is provided in the bumper member (1).
In the initial stage of the compressive deformation, it is possible to allow a margin for the load until the deformed bumper member (1) fills the gap (26) and comes into contact with the expansion receiving portion (25) of the holding bracket (2). The bumper member (1) is provided so that the spring constant at the initial stage of the compression deformation can be kept small, that is, it can absorb the impact of a relatively small load.

Therefore, the distance (S) is less than 2 mm,
In particular, if the diameter is too small, such as less than 1 mm, the bumper member (1) immediately comes into contact with the expansion receiving portion (25) of the holding fitting (2) at the time of compressive deformation, and it is difficult to realize the above-mentioned effects. It is obvious that it becomes. If the distance (S) is more than 4 mm, especially more than 5 mm, when the bumper member (1) is compressed and deformed, the deformed bumper member (1) comes into contact with the expansion receiving portion (25). Until the deformation is suppressed, the disadvantage that the bumper member (1) is excessively deformed occurs. Therefore, it is practically preferable to set the gap (26) in the above range.

In the case shown in the drawing, the extension receiving portions (25) and (25) are bent outward at the ends thereof to extend a flange-like edge (27), and the bumper member (1) has a corner. So that it does not touch the edge with This flanged edge (2
7) a flange-like edge (28) bent upward on both sides of the expansion receiving portion (25) and bent outward at the edges of the other side walls (21b) and (21b). It is continuous.

The shape in which the bumper member (1) is held by the holding fitting (2) is shown in FIGS. 1 to 3, and the base end (11) of the bumper member (1) is held by the holding fitting ( It is fitted and fixed to the cup-shaped portion (20) of 2). At this time, the plurality of locking pieces (24) of the holding fitting (2) engage with the engagement grooves (13) of the bumper member (1),
The bumper member (1) is firmly locked to the holding bracket (2).

The bound bumper (A) is located on the side of the side wall (21a) where the extended receiving portion (25) of the holding metal fitting (2) is formed at a position where the bound bumper (A) comes into contact with a columnar member (B) such as an axle. Is attached to the vehicle body so as to be positioned parallel to the cylindrical member (B).

Here, in the above mounting state,
It is assumed that the tip end surface of the bumper member (1) below the bound bumper (A) in FIG. 1 abuts on a cylindrical member (B) such as an axle. At this time, the bumper member (1) has a substantially square columnar shape, and its tip end surface has a concave receiving portion (1).
Since (8) is formed, the tip end surface of the bumper member (1) can be stably abutted against the cylindrical member (B) without displacement.

When the bumper member (1) made of urethane foam is compressed and deformed by applying a load upward from below in FIG. 1 due to the contact with the cylindrical member (B), the bumper member (1) is compressed. The main part (12) is deformed so as to bulge outward largely on the side surface (12a) along both sides of the cylindrical member (B) (a chain line in FIG. 1). When the bulging deformation exceeds a certain level, the side projecting portion (15) comes into contact with the expansion receiving portion (25) extending from the side wall (21a), but the expansion receiving portion (25) gradually and obliquely outwardly. Since the bumper member (1) is formed so as to expand, in the initial stage of the compressive deformation of the bumper member (1), the situation where the bulged deformed bumper member (1) abuts against the expansion receiving portion (25) excessively is prevented, It shows larger deformation than rubber material under relatively small load, and provides good shock absorption.

In particular, as in the above embodiment, a gap is provided between the expansion receiving portion (25) of the holding fitting (2) and the tapered surface (14a) of the side projection (15) of the bumper member (1). In the case where the bumper member (26) is held, there is a margin until the deformed bumper member (1) fills the gap (26) and comes into contact with the holding fitting (2) in the initial stage of the compression deformation of the bumper member (1). Thus, in the initial stage of the deformation, a spring constant smaller than that of the rubber material made of urethane foam can be favorably maintained, and the impact of a relatively small load can be favorably absorbed.

Further, in a state in which the compressive deformation of the bumper member (1) is advanced by applying a large load of a certain value or more, the side surface (12a) of the main body (12) is greatly expanded and deformed outward. However, the bulging portion of the side surface, that is, the side projecting portion (15) comes into contact with the inner side surface of the oblique expansion receiving portion (25) of the side wall (21a), so that a large spring constant is exhibited, and excessive bulging deformation occurs. Is suppressed. In addition, the bulging portion is not strongly pressed by the edge of the side wall (21a) of the holding metal fitting (2), so that the occurrence of breakage from the contact portion can be prevented, and the service life can be extended.

Therefore, the bound bumper (A)
Accordingly, the elastic property can be changed between the initial stage and the subsequent stage of the compressive deformation of the bumper member (1) so that the bumper member can be used as having a plurality of stages of characteristics, and even a relatively small amplitude vibration can be absorbed. Bumper (A) quality,
In particular, the quality in use such as quietness and vibration suppression characteristics of vehicles and the like can be remarkably improved.

It should be noted that the present invention is not limited to the above embodiment, but may include a wide variety of modifications without departing from the spirit of the present invention. In particular, the dimension examples of the respective members in the embodiments are merely examples when the present inventor embodies the invention for a specific vehicle, and the dimensions are different if the vehicle and the place where the invention is implemented are different. Can be implemented numerically.

[0046]

As described above, according to the bound bumper of the present invention, it can be suitably used at a position where it comes into contact with a columnar member such as an axle. In the early stages of deformation,
While maintaining a small spring constant compared to rubber material, it shows a large spring constant at the time of compressive deformation of a certain amount or more, can suppress excessive bulging deformation due to compression, and can avoid pressing against the edge of the holding bracket The occurrence of breakage and the like can be prevented, and the life can be extended.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a bound bumper according to an embodiment of the present invention.

FIG. 2 is a bottom view of the bound bumper.

FIG. 3 is a sectional view of the bound bumper taken along line X3-X3 in FIG. 1;

FIG. 4 is a front view of a bumper member of the bound bumper.

FIG. 5 is a plan view of the bumper member.

FIG. 6 is a sectional view of the bumper member taken along line X6-X6 in FIG. 4;

FIG. 7 is a half vertical sectional front view of a holding bracket of the bound bumper.

FIG. 8 is a bottom view of the holding fixture.

FIG. 9 is a cross-sectional view of the holding bracket taken along line X9-X9 in FIG. 7;

FIG. 10 is a cross-sectional view showing an example of a conventional bound bumper.

FIG. 11 is a graph showing a load-deflection characteristic of the bound bumper.

[Explanation of symbols]

 (A) Column-shaped member such as a bound bumper axle (B) (1) Bumper member (11) Base end (12) Main part (12a) (12a) (12b) (12b) Four side faces (13) Engagement Groove (14a) (14b) Tapered surface (15) Side projection (18) Concave receiving surface (2) Holding bracket (20) Cup-shaped part (21a) (21a) (21b) (21b) Four side walls (24) Engagement piece (25) (25) Extension receiving part (26) Gap (27) (28) Flange-like rim (3) Bracket (S) Gap spacing (L) Gap extension length

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D001 AA17 BA05 DA14 3J059 AA03 BA64 BC06 BD01 DA16 GA02 3J066 AA02 AA23 BA01 BB01 BC01 BD05

Claims (7)

[Claims] 1. A bound bumper comprising a bumper member made of an elastic material and a holding fitting for holding a base end of the bumper member, wherein the bumper member is continuous with the base end and the base end. The main body and the urethane foam are formed integrally with each other in the form of a column having a substantially rectangular shape in a plane, and the holding fitting includes a substantially rectangular cup-shaped portion in which a base end of the bumper member is fitted and engaged.
A bound bumper characterized in that an extension receiving portion gradually and obliquely outwardly extends from one of the opposite side walls of the cup-shaped portion. 2. The main body of the bumper member has a projecting shape in which a side surface on a side corresponding to the expansion receiving portion of the holding metal has a gap between the side surface and the expansion receiving portion. 2. The apparatus according to claim 1, wherein said side projection is provided so as to abut on an inner side surface of said expansion receiving portion during compression deformation.
Bound bumper described in. 3. The bound bumper according to claim 2, wherein a gap of 1 to 5 mm is provided between a side projection of the bumper member and an expansion receiving portion of the holding bracket. 4. A front end surface of the bumper member has a concave shape having a curvature axis in one of a vertical direction and a horizontal direction, and a side surface parallel to the curvature axis of the concave shape has an outwardly projecting shape. The bound bumper according to claim 2 or 3. 5. The bound bumper according to claim 1, wherein a flange-shaped edge bent outward is provided at an end edge of the extension receiving portion of the holding fitting. 6. The bound bumper according to any one of claims 1 to 5, wherein a flange-like edge bent outward is provided at an edge of the other opposing side wall of the holding fitting. . 7. The bound bumper according to claim 1, wherein the extension receiving portion of the holding metal has an angle of 30 ° to 60 ° with respect to the bumper axis.