JP3489024B2 - Bound bumper - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a bound bumper for an automobile.

[0002]

2. Description of the Related Art A bounding bumper installed and used in an automobile suspension or the like is mainly for alleviating impact at the time of bouncing. As the elastic material of the bumper member of the bound bumper, a rubber material which is more elastic and has a higher breaking strength than before is generally used.

In this bound bumper, as shown in FIG. 10, generally, a base end portion (111) of a bumper member (101) integrally formed of a rubber material has a cup-shaped holding metal fitting ( 102), and is held and held by a locking piece (124) provided on the side wall (121) so as not to be pulled out, and the holding metal fitting (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 amount is relatively small becomes too large.

This point will be described with reference to FIG. 11 showing the load-deflection characteristics of a bound bumper made of 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 property of a small spring constant is required to absorb a shock from the road surface, and a region where the displacement is relatively large. Then, a large spring constant is required so that the vehicle body and the suspension do not come close to each other excessively or more than 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 through the bound bumper, which reduces the quietness of the vehicle.

Therefore, in order to solve the above problems, it is proposed to use urethane foam as the bumper member, which has a small spring constant and a deflection amount in the initial state of the load-deflection characteristic which is larger than that of the rubber material. 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 (chain line in FIG. 11). However, as in the case of the bumper member made of the rubber material shown in FIG. 10, when the base end portion is fitted and fixed to the cup-shaped holding metal fitting and used, it is laterally deformed when a large load is compressed and deformed. A large bulge (chain line in Fig. 10), the bulged portion is strongly pressed against the edge of the side wall of the holding metal fitting, and as a result of repeating this, a fracture occurs at this portion, shortening its service life. Will be lost.

In particular, when a bound bumper made of urethane foam is used at a position where it comes into contact with a substantially horizontal columnar member, the tip end surface of the bumper member is a columnar member such as the axle. When it comes into contact with and is deformed by compression, it does not swell so much in the extending direction of the cylindrical member, but it swells more than usual in both lateral directions of the cylindrical member. The edge is strongly pressed, and this is repeated, so that the above-mentioned problem of occurrence of breakage becomes remarkable.

The present invention has been made in view of the above, and has the above-mentioned problems when a bound bumper is preferably used at a position where it comes into contact with a columnar member such as an axle, particularly when urethane foam is used as the bumper member. Provided is a bound bumper which has been solved and which has no fear of breakage, has a large spring constant when a certain amount of bending occurs, and can have a long life.

[0012]

The bound bumper of the present invention is a bound bumper comprising a bumper member made of an elastic material and a holding metal fitting for holding a base end portion of the bumper member, wherein the bumper member comprises: Almost perpendicular to the top
A base end portion having a side surface and a main body portion that continuously protrudes downward from the base end portion are integrally formed of urethane foam into a columnar shape having a substantially quadrangular plane , and the main body portion has a tip end thereof. Face is vertical
It has a concave shape with a curvature axis in one horizontal direction, and
Out of the side surfaces of the circumference, the direction parallel to the curvature axis of the concave shape
One of the opposite side surfaces is the side surface of the base end portion.
From the taper surface that is continuously inclined outward from
Due to the taper surface that is gently inclined inward,
It has an outwardly protruding shape, and
In the side surface, the inner side is continuous from the side surface of the base end.
Has a taper shape that is gently inclined to the top surface , while the holding metal fitting is formed in a substantially vertical direction downward from the top surface portion.
At the base end of the bumper member with the four side walls extending
A cup-shaped portion having a substantially quadrangular shape, which is opened downward in a corresponding shape and to which the base end portion is fitted and engaged, is provided, and the side surface tension of the bumper member of the four side walls of the cup-shaped portion.
Ri gradually extended receiving portion extending obliquely outwardly on both side walls facing each other of the out portion and the corresponding side are extended, the extension receiving
The hook portion is a taper on the side of the base end of the protruding portion on the side surface.
Holds a gap between the tapered surface and the taper surface.
It is formed so as to have a certain amount or more at the time of compressive deformation.
The overhanging portion contacts the inner surface of the expansion receiving portion.
It is characterized by being provided as described above.

This bound bumper is mounted on the vehicle body so that the side of the side wall of the holding metal fitting on which the expansion receiving portions of the four sides are formed is located parallel to the columnar member at a position where it comes into contact with the columnar member. Attach and use.

In this use, when bouncing occurs,
The columnar member comes into contact with the tip end surface of the bumper member and a load is applied to the bumper member, which causes the bumper member to compressively deform. However, due to urethane foam having a spring constant smaller than that of the rubber material, at the initial stage of the compressive deformation, It exhibits greater flexural deformation than rubber materials with a small load, and absorbs impact well. In addition, when a large load above a certain level is applied and the bumper member undergoes large compressive deformation, the compressive deformation causes
The side surface of the main body, particularly the side surface along the extending direction of the circular member, will largely bulge and deform outward, but the bulging portion of this side surface abuts the inner surface of the oblique expansion receiving portion of the side wall. , Shows a large spring constant and suppresses excessive bulge deformation. Moreover, the bulging portion is not strongly pressed against the edge of the side wall of the holding metal fitting, and the occurrence of breakage from the abutting portion can be prevented.

[0015]

Further , as described above, since there is a gap between the side projecting portion of the bumper member and the expansion receiving portion of the holding metal fitting, in the initial stage of the compressive deformation of the bumper member, the side projecting which is bulged and deformed. The spring constant at the initial stage of flexural deformation can be kept small by absorbing the compression deformation allowance until the part fills this gap and contacts the expansion receiving part of the holding metal fitting, and also absorbs the impact of a comparatively small load. You can Moreover, when the bumper member is compressed and deformed by a certain amount or more, the side surface protruding portion abuts against the expansion receiving surface, so that excessive bulging deformation can be suppressed as described above.

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

In the bound bumper, a tip end surface of the bumper member has a concave shape having a curvature axis in one longitudinal and lateral directions, and a side surface parallel to the curvature axis of the concave shape has an outward projecting shape. By this, the tip end surface of the bumper member can contact the columnar member such as the axle without displacement, the contact state is stable, and it extends along the extending direction of the circular member during compression deformation. There is no possibility that both side surfaces bulge and deform substantially evenly and one side surface is pressed against the expansion receiving portion excessively strongly.

Further, it is preferable that a flange-shaped edge which is bent and extended in an outward direction away from the bumper member is provided at an end edge of the expansion receiving portion of the holding metal fitting. This allows
Even if the side surface protruding portion is largely bulged and deformed, the bulged portion is not strongly pressed by the corner edge, and the occurrence of breakage can be reliably prevented.

It is preferable to provide a flange-shaped edge bent and extended outward in a direction away from the bumper member also at the edge of the other side wall of the holding metal fitting which opposes the bumper on the side corresponding to the side wall. Even if the side surface of the main body of the member bulges and deforms, it is possible to prevent the occurrence of breakage due to being pressed against the side wall edge.

The expansion receiving portion of the holding metal member is inclined with respect to the bumper shaft center within an angle range of 30 ° to 60 °, so that the bulging deformation of the side surface of the bumper member and the like can be restrained and restored. Above all preferred.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described based on an embodiment shown in the drawings.

1 to 9 show one embodiment of the bound bumper of the present invention. FIG. 1 is a vertical sectional view of the bound bumper, FIG. 2 is a bottom view of the bound bumper, and FIG. 3 is the bound. It is sectional drawing in the X3-X3 line 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 sectional view of the bumper member taken along line X6-X6 in FIG.
FIG. 7 is a vertical sectional front view of a half part of the holding metal fitting of the bound bumper, FIG. 8 is a bottom view of the holding metal fitting, and FIG. 9 is a cross-sectional view of the holding metal fitting 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 the one that is used by being placed at a position where it comes into contact with a columnar member such as an axle when a bounce occurs, and when a member on the suspension side comes close to the vehicle body due to bouncing of the vehicle body, a columnar member such as an axle ( B) comes into contact with the tip surface of the bumper to fulfill a cushioning function.

[0025] The bound bumper (A) is, as shown in FIG.
As described above, the base end portion (11) having a side surface substantially vertical to the top surface and the main body portion (12) continuously protruding from the base end portion (11) are formed of urethane foam as an elastic material and have a columnar shape of a substantially quadrangular plane. A bumper member (1) integrally formed with the holding metal fitting (2) for holding the 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 a substantially rectangular shape, for example, a substantially rectangular base end portion (11) held by a holding metal fitting (2), and an engagement groove (13) formed over the entire circumference. Has been formed. The main body portion (12) continuously protruding downward from the base end portion (11) is
One of the four side surfaces (12a) (12a) (12b) (12b), for example, the long side facing side surfaces (12a) (12a)
In, the taper surface (14a) continuously inclined outward from the base end portion (11) and the taper surface (14b) gently inclined inward from the taper surface (14a) extend outward. It has a shape and is wider than the base end (11). (15) shows the side protruding part. Further, the side surfaces (12b) (12b) on the other short side have a taper shape which is continuous from the base end portion (11) and is gently inclined inward as it is. As a result, the main body (12) has a truncated pyramid shape (inverted trapezoidal cross section) as a whole toward the lower end.

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

Further, at the tip end surface of the main body portion (12), a concave receiving surface (where the axis of curvature is in a direction perpendicular to the paper surface of FIG. 1, that is, in a direction parallel to the side surface (12a) having the overhang shape ( 18) has been formed. This concave receiving surface (18)
Since the bound bumper (A) is disposed and used at a position where it comes into contact with the columnar member (B) such as an axle as described above, the tip end surface of the bumper member (1) is the columnar member (B).
Is formed so as to surely abut.

On the other hand, as shown in FIGS. 7 to 9, the holding metal fitting (2) has a base end portion (1) of the bumper member (1).
The top surface ( 22 ) and the top surface so that
The four side walls that extend in a substantially vertical direction downward from the
Becomes a serial proximal end (11) substantially rectangular shape corresponding to the cup-shaped portion opening downward direction forms a (substantially rectangular in the case of FIG.) (20), the top of the cup-shaped portion (20) The surface portion (22) is integrally fixed to the mounting bracket (3) having a substantially square shape in a plane at four welding positions (23) by means such as spot welding. The bracket (3) has a long rectangular plate shape, a pair of bolt holes (31) are formed near both ends in the longitudinal direction, and a bolt or the like is inserted through each bolt hole (31) to form a vehicle body (not shown). ) Is attached.

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

One of the four side walls of the cup-shaped part (20), in particular, the side faces (12a) (12a) having the projecting shape of the bumper member (1), which are opposed to each other on the long side, facing each other. (21a) (21a) has an expansion receiving portion (2) that gradually extends outwardly as it is separated from the side wall.
5) (25) is integrally extended, and is formed so that the protruding portions (15) of the side surfaces (12a) (12a) come into contact with each other when the bumper member (1) is compressed and deformed by a certain amount or more. Thus, it is possible to prevent excessive flexural deformation of the bumper member (1).

The expansion receiving part (25) has a slight gap (26) between the expansion receiving part (25) and the tapered surface (14a) of the side surface projecting part (15) of the bumper member (1) on the base end part (11) side.
Is formed so as to retain the taper and extends slightly outward from the tapered surface (14a).

The inclination of the expansion receiving portion (25) is set within an angle range of 30 ° to 60 ° with respect to the axial center of the bumper, so that the side surface overhanging portion (15) of the bumper member (1) and the like are appropriately expanded. It is preferable because deformation can be allowed and excessive bulging deformation can be suppressed. From such an effect, the angle range is more preferably 30 ° to 50 °. In addition, the tapered surface (14) of the side surface overhanging portion (15) of the bumper member (1).
The angle a) corresponds to this.

The interval (S) of the above-mentioned 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 bulge deformation at the time of compressive deformation of a certain amount or more. It is preferably 2 to 4 mm. Further, the length (L) of the gap (26) in the extending direction is preferably 6 to 12 mm from the viewpoint of suppressing the bulging deformation of the bumper member (1) and preventing breakage due to pressing, and more preferably Is 8 to 10 mm.

The gap (26) is provided in the bumper member (1).
In the initial stage of the compression deformation of the above, it is possible to allow a margin for the load until the deformed bumper member (1) fills this gap (26) and contacts the expansion receiving portion (25) of the holding metal fitting (2). The bumper member (1) is provided so that the spring constant at the initial stage of compression deformation can be kept small, that is, the impact of a relatively small load can be absorbed.

Therefore, the spacing (S) is less than 2 mm,
In particular, if it is too small, such as less than 1 mm, it will come into contact with the expansion receiving portion (25) of the holding metal fitting (2) immediately when the bumper member (1) is compressed and deformed, making it difficult to realize the above-mentioned effects. It is clear that If the spacing (S) exceeds 4 mm, and particularly exceeds 5 mm, the deformed bumper member (1) abuts the expansion receiving portion (25) during the compression deformation of the bumper member (1). Therefore, the bumper member (1) may be excessively deformed before the deformation is suppressed. Therefore, it is preferable in practice to set the gap (26) within the above range.

In the figure, the expansion receiving portions (25) and (25) are provided at their end edges with outwardly bent flange-like edges (27) so that the bumper member (1) has corners. It is designed so that it does not come into contact with the edge with a groove. This flange edge (2
7) is a flange-like edge (28) which is formed by bending upward on both sides of the expansion receiving portion (25) and which is bent and extended outward at the edge of the other side wall (21b) (21b). It is continuous.

The shape in which the bumper member (1) is held by the holding metal fitting (2) is shown in FIGS. 1 to 3, and the base end portion (11) of the bumper member (1) is held by the holding metal fitting (2). 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 metal fitting (2) are engaged with the engagement groove (13) of the bumper member (1),
The bumper member (1) is firmly locked to the holding metal fitting (2).

This bound bumper (A) is located on the side wall (21a) where the expansion receiving portion (25) of the holding metal fitting (2) is formed at a position where it 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 mounting state as described above,
It is assumed that the tip end surface of the bumper member (1) on the lower side of the bound bumper (A) in FIG. 1 comes into contact with a columnar member (B) such as an axle. At this time, the bumper member (1) is in the shape of a substantially quadrangular column, and the tip surface of the bumper member (1) is concave.
Since 8) is formed, the tip end surface of the bumper member (1) can contact the columnar member (B) with good stability without displacement.

When the bumper member (1) made of urethane foam is compressed and deformed by a load applied from the lower side to the upper side in FIG. 1 by contact with the cylindrical member (B), the bumper member (1) is deformed. The main body portion (12) of (1) is deformed so as to largely bulge outward on the side faces (12a) along both sides of the cylindrical member (B) (chain line in FIG. 1). When the bulge deformation exceeds a certain level, the side surface protruding portion (15) comes into contact with the expansion receiving portion (25) extended from the side wall (21a), but the expansion receiving portion (25) is gradually inclined outward. Since the bumper member (1) is formed to expand, it is possible to prevent the bulging and deforming bumper member (1) from excessively abutting the expansion receiving portion (25) in the initial stage of compression deformation of the bumper member (1). It exhibits greater flexural deformation than rubber materials with a relatively small load, and absorbs impact well.

Particularly, as in the above embodiment, a gap is formed between the expansion receiving portion (25) of the holding metal fitting (2) and the tapered surface (14a) of the side surface protruding portion (15) of the bumper member (1). In the case where the bumper member (1) is held, there is a margin until the deformed bumper member (1) fills the gap (26) and comes into contact with the holding metal fitting (2) in the initial stage of the compressive 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 satisfactorily maintained, and a shock of a relatively small load can be satisfactorily absorbed.

In addition, when the bumper member (1) is compressed and deformed by applying a large load of a certain amount or more, the side surface (12a) of the main body (12) is largely expanded and deformed outward. However, the bulging portion of the side surface, that is, the side surface bulging portion (15) comes into contact with the inner side surface of the oblique expansion receiving portion (25) of the side wall (21a), thereby showing a large spring constant and excessive bulging deformation. Suppressed. Moreover, the bulging portion is not strongly pressed against the end edge of the side wall (21a) of the holding metal fitting (2), the occurrence of breakage from the abutting portion can be prevented, and the life can be extended.

Therefore, this bound bumper (A)
As a result, the elastic characteristics can be changed at the initial stage of the compressive deformation of the bumper member (1) and after that, and it can be used as having a multi-stage characteristic, and it is possible to absorb even a vibration with a relatively small amplitude, and to bounce. Bumper (A) quality,
In particular, it is possible to remarkably improve the quietness of a vehicle or the like, the quality of use such as vibration suppressing characteristics, and the like.

It should be noted that the present invention is not limited to the above embodiments, but may include a wide variety of modifications without departing from the spirit of the present invention. In particular, the dimensional examples of the above-mentioned 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 or the place where the invention is implemented is different. It can be implemented numerically.

[0046]

As described above, according to the bound bumper of the present invention, the bound bumper can be preferably used at a position where it comes into contact with a columnar member such as an axle, and in particular, even though urethane foam is used as the bumper member, compression is achieved. In the early stages of deformation,
The spring constant is smaller than that of rubber material, while it exhibits a large spring constant when it is compressed and deformed over a certain amount, and it is possible to suppress excessive bulging deformation due to compression and to avoid pressing against the edge of the holding metal fitting. It is possible to prevent the occurrence of breakage and the like and prolong the service life.

[Brief description of drawings]

FIG. 1 is a vertical 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 same bound bumper.

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

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

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

FIG. 8 is a bottom view of the holding metal fitting.

9 is a cross-sectional view of the holding metal fitting 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 load-deflection characteristics of the bound bumper.

[Explanation of symbols]

(A) Cylindrical member such as bound bumper axle (B) (1) Bumper member (11) Base end (12) Main part (12a) (12a) (12b) (12b) Four sides (13) Engagement groove (14a) (14b) Tapered surface (15) Side overhang (18) Recessed receiving surface (2) Holding bracket (20) Cup-shaped part (21a) (21a) (21b) (21b) Four side walls (24) Locking piece (25) (25) Expansion receiver (26) Gap (27) (28) Flange edge (3) Bracket (S) Gap interval (L) Length of gap in extension direction

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-300931 (JP, A) JP-A-49-18961 (JP, A) JP-A-2000-118221 (JP, A) JP-A-2000-291707 ( JP, A) Actual Kaihei 7-41099 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16F 1/00-6/00 F16F 7/00-7/14 B60G 1 / 00-25/00

Claims (5)

(57) [Claims] 1. A bound bumper comprising a bumper member made of an elastic material and a holding metal fitting for holding a base end portion of the bumper member, wherein the bumper member has a side surface substantially vertical to a top surface. An end portion and a main body portion which continuously projects downward from the base end portion are integrally formed by urethane foam into a columnar shape having a substantially rectangular plane.
The main body portion has its front end surface bent in one direction in the vertical and horizontal directions.
It has a concave shape with a rate axis, and it has four side walls.
Then, on one of the opposite side surfaces, the side of the base end portion
The taper surface that is continuously inclined outward from the surface and the taper surface
The taper surface gently inclined inward from the base end
More outward than the other, and facing each other
In the side surface to be
Has a taper shape that is gently inclined to the side, while the holding metal member is formed on the top surface portion and downward from the top surface portion.
The bumper member includes four side walls extending in the vertical direction.
A substantially quadrilateral cup-shaped portion having a shape corresponding to the base end portion of the cup-shaped portion, the cup-shaped portion is opened downward, and the base end portion is fitted and engaged . Of which, the bumper member
On both side walls opposite to each other on the side corresponding to the above-mentioned side projecting portion, there is provided an expansion receiving portion that gradually expands outward .
The expansion receiving portion is a base in the side protruding portion.
The same inclination as the taper surface on the end side, and between the taper surface
It is formed to have a gap in the
When forming, the side projecting portion is the inner surface of the expansion receiving portion.
Bound bumper characterized in that it is provided so as to abut against . 2. Between the extended receiving portion of the side projecting portion of the bumper member and the holding metal fitting, bound bumper according to claim 1 carrying a gap 1 to 5 mm. 3. The bound bumper according to claim 1, wherein a flange-shaped edge bent outward is provided at an end edge of the expansion receiving portion of the holding metal fitting. 4. A edges of sidewalls other opposite of the holding fixture, bound bumper according to any one of claims 1 to 3, a flange-like rim which made bent extending outward are provided . 5. The extension receiving portion of the holding bracket, bound bumper according to any one of claims 1 to 4 which forms an inclination angle range of 30 ° to 60 ° with respect to the bumper axis.