JP2000255240A - Suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension device having a structure excellent in compactness and lower cost and providing a nonlinear characteristic. SOLUTION: This suspension device has a rubber spring unit 11 between a vehicle body 2 and a leaf spring 3, the rubber spring unit 11 being of a non- overhanging simple rubber spring unit structure with a pair of front and rear brackets 21, 23 provided in the vehicle body 2, a center bracket 13 disposed between the brackets 21, 23, rubber 14 connecting the opposite side face of the center bracket to the side face of each bracket, and rubber 15 positioned directly above the leaf spring 3 and mounted on the lower surface of the center bracket 13. Shear deformation of the rubber 14 and compressive deformation of the rubber 15 which occur when the rubber 15 abuts the leaf spring 3 allow the spring constant of the suspension device to vary nonlinearly according to the load applied when the vehicle is loaded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a suspension device having a rubber spring unit provided between a vehicle body and a leaf spring.

[0002]

2. Description of the Related Art In a truck (vehicle), an axle (axle) is supported to be movable up and down by using a suspension device using a leaf spring.

However, the leaf spring alone cannot cope with a change in load between when the truck is empty and when the truck is loaded.

Therefore, a helper spring is provided between the vehicle body and the leaf spring to reduce the spring constant of the suspension device only when the vehicle is empty, depending on the leaf spring alone, and to reduce the load applied from the vehicle body when the vehicle is loaded. In order to increase the spring constant of the suspension device, it is performed.

[0005] However, simply installing a helper spring does not smoothly change the spring constant according to the load, so that a good ride comfort may not be obtained when the vehicle is loaded.

Therefore, recently, a rubber spring unit is used to give a non-linear characteristic to a spring constant of a suspension device.

More specifically, as shown in JP-A-9-272320, a large number of rubber elastic bodies (small block pieces) are used.
A rubber spring unit is proposed that uses a pair of pillar-shaped rubber springs formed by alternately vulcanizing and adhering a restraining plate and assembling them into a V-shape or inverted V-shape between the vehicle body and the leaf spring. Have been.

[0008] That is, the rubber spring unit is
The load applied from the vehicle body is simultaneously borne by the compression and shear deformation of the forward-tilting columnar rubber spring and the backward-tilting columnar rubber spring, and the compression of the rubber elastic body, which deforms according to the load applied during loading Due to the simultaneous deformation in the direction and the shear direction, the spring constant of the suspension device is increased nonlinearly.

[0009]

By the way, the rubber spring unit is required to be inexpensive and compact from the viewpoints of installation properties and products.

However, this rubber spring unit has a structure in which a columnar rubber spring is arranged to be inclined forward or backward to secure a predetermined vertical stroke of the suspension device, so that the rubber spring end can easily protrude greatly in the front-rear direction. , Easy to be large. In addition, since the rubber spring has a structure in which a large number of rubber elastic bodies and restraint plates are alternately vulcanized and bonded to form a column, the structure is considerably complicated. In addition, since the production of the rubber spring requires considerable time and effort, the suspension device tends to be expensive in cost, and there is a need for improvement in this respect.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a suspension device capable of obtaining a non-linear characteristic while reducing the size and cost. is there.

[0012]

According to a first aspect of the present invention, there is provided a suspension device, comprising: a rubber spring unit provided between a vehicle body and a leaf spring; A pair of support brackets are formed so as to be lined up with each other, a center bracket is disposed between the support brackets, and a first rubber is connected between the side surface of the opposed center bracket and the side surface of each support bracket by a first rubber. Alternatively, a second rubber is mounted on the lower surface of the center bracket by positioning the second rubber on the lower surface of the center bracket, and a simple structure in which the second rubber is in contact with a leaf spring or an axle is employed. Due to the deformation of the first rubber in the shear direction and the deformation of the second rubber in the compression direction,
The spring constant of the suspension device is changed non-linearly according to the applied load.

[0013] The suspension device according to claim 2 is
In addition to the above objects, in order to further suppress the excessive stroke of the suspension device without feeling of thrust, a stopper is provided at a predetermined distance directly above the center bracket to compress and deform the second rubber which gives non-linear characteristics. Utilizing the technology, the excessive stroke of the suspension device is suppressed while reducing the impact caused by the thrust.

In particular, by employing a stopper capable of adjusting the distance from the center bracket, it is possible to limit the stroke of the suspension device according to various vehicles without changing the rubber spring unit. In addition, if the stopper has a structure using a plurality of plate-shaped spacers having different thickness dimensions, the stroke can be limited with a simple structure.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one embodiment shown in FIGS.

FIG. 1 shows a rear suspension device for suspending, for example, a rear wheel (not shown) of a truck (vehicle). In FIG. 1, reference numeral 1 denotes a truck frame (constituting a vehicle body). The frame 1 has a ladder shape having a pair of side frames 2 extending in the vehicle front-rear direction. A pair of left and right leaf springs 3 (for example, a plurality of leaves 3a are vertically That are stacked on top of each other). More specifically, in each case, the leaf spring 3 rotatably supports an eyeball portion 4a formed at the front end on a bracket 5 fixed to the lower end of the side frame 2 by, for example, a bolt. The formed eyeball portion 4b is attached to a lower end of a frame portion behind the bracket by, for example, a bolt 6 fixed to a bracket 6 by being rotatably supported via a shackle link 7. A rear axle 10 (axle) is attached to an intermediate portion between the left and right leaf springs 3 using a pair of front and rear U bolts 8, a leaf holding member 8a, and a partial axle holding member 9. As a result, the rear axle 1
0 is movably supported up and down.

Between the rear axle 10 and the side frame 2, a pair of left and right rubber spring units 11 (only one side is shown) which are essential parts of the present invention are attached. The rubber spring 11 includes two types of brackets 12 and 13 and two types of rubbers 14 and 15.
(For shear deformation / compression deformation).

The structure of each part will be described. The bracket 12 includes, for example, a front bracket 21 fixed to the lower surface of a side rail immediately above the leaf spring 3 with, for example, bolts 20 and a rear side located at a predetermined distance. A structure using a rear bracket 23 (corresponding to a support bracket) fixed by bolts 22 is used. Specifically, for example, the front / rear brackets 21 and
3 is formed in an L-shape, having a columnar holding portion 24 protruding downward from the lower surface of the side frame 2 and a bolt seat 25 extending along the lower surface of the frame. And
Holder 24 of front / rear brackets 21 and 23
However, the leaf springs 3 are arranged on the lower surface of the frame so as to face each other in the front-rear direction with respect to the longitudinal center of the leaf springs 3. Thereby, the pair of holding portions 24 are arranged at a predetermined distance in the vehicle longitudinal direction. Note that, on the inner surfaces of the holding portions 24 facing each other, for example, an inclined surface 26 that retreats downward is formed.

The brackets 13 (corresponding to center brackets) are arranged between the inclined surfaces 26 of the respective holding portions 24. The bracket 13 is formed in an outer shape that is accommodated in a space sandwiched between the inclined surfaces 26. Specifically, the bracket 13 is formed by bending a band plate member into a U-shape, specifically having an intermediate wall 13a on the lower side, and a pair of end walls 13b extending upward from the intermediate portion 13a following the inclination of the inclined surface 26. , And each end wall 13b faces each inclined surface 26 with a predetermined gap.

The inclined surface 2 of the front bracket 21
6 and the front end wall 13b of the bracket 13, and the inclined surface 26 of the rear bracket 23 and the rear end wall 13b of the bracket 13 are connected by the rubber 14, respectively. At a point just above the leaf spring 3 distant from the leaf spring 3, it is supported so as to be vertically movable.

The rubber 15 is attached to the lower surface of the intermediate wall 13a so as to protrude toward the leaf spring 3 from the lower surface. As the rubber 15, for example, a rubber block having a triangular cross section whose width in the front-rear direction becomes narrower toward the tip is used. The tip of the rubber 15 is positioned away from the leaf holding member 8a (the portion forming the upper part of the leaf spring 3), that is, positioned at a point away from the leaf holding member 8a by a predetermined distance,
When the vehicle is empty, it is separated from the leaf holding member 8a. When the vehicle is loaded, when the loading amount increases, the tip of the rubber 15 is configured to contact the upper surface of the leaf holding member 8a.

With these two types of rubbers 14 and 15,
Bracket 13 according to contact with leaf holding member 8a
Is applied to the rubber 14, deformation in the shear direction,
The rubber 15 is borne by the deformation in the compression direction.

A stopper 2 for limiting the stroke of the leaf spring 3 is provided above the bracket 13.
8 are formed. Specifically, in the stopper 28, the lower wall 2a facing the bracket 13 is kept as it is so as to suppress excessive upward movement of the bracket 13 so as to utilize the structure in which the side frame 2 is disposed immediately above the bracket 13. A structure that is also used as a stopper member to serve as a bump stopper is used.

The lower wall 2a facing the bracket 13
The lower surface of the spacer 31 is formed of various plates having different thicknesses by a bolt hole 29 drilled in the wall portion and a bolt 30 passing through the bolt hole 29 (FIG.
The state in which the spacers 31 of the types are mounted is shown) can be fixed. Each of the spacers 31 has a bracket 1
A plate having an area necessary to receive the upper end of the bracket 3 is used. The distance from the upper end of the bracket 13 to the stopper 28 is determined by the presence or absence of the spacer 31 and the addition / replacement of the spacer 31 to the vehicle or vehicle type. It can be adjusted according to the conditions.

The bracket 13 with the rubber 15 for compressive deformation attached to the tip is supported by the rubber for shear 13 so as to be able to move up and down. The rubber spring unit 11 can be changed in a non-linear manner according to the load applied by the spring constant of the suspension device.

That is, when the truck is empty, as shown in FIG. 1, the bracket 13 is positioned at a position distant from the leaf spring 3, so that the rear suspension device applies a load with a low spring constant depending only on the leaf spring 3. receive.

When the truck is loaded, the leaf spring 3 flexes as the load increases and the rubber 15 contacts the leaf holding member 8a as shown in FIG. Begins to deform in the shear direction, and the shear deformation bears the load.

Here, since only the shear deformation of the rubber 14 occurs (since the shear deformation is more likely to occur than the compression deformation), the rear suspension device follows the spring constant of the leaf spring 3 by the shear deformation of the rubber 14.
A low spring constant is obtained.

When the load increases and the shear deformation gradually progresses, the rubber 15 starts to be deformed in the compression direction, and bears the load even in the compression deformation.

Here, since both the shear deformation of the rubber 14 and the compression deformation of the rubber 15 occur, the spring constant of the rear suspension device gradually rises.

Further, as shown by the two-dot chain line in FIG. 2, when the loading load increases until the bracket 13 comes into contact with the spacer 31 forming the stopper 28, the movement of the bracket 13 is restricted and the shear deformation of the rubber 14 ends. .

Then, the load is received only by the compressive deformation of the rubber 15 and the spring constant of the suspension device shows a behavior of increasing, and the load is borne by this high spring constant. And, by this behavior, the excessive upward leaf spring 3
Movement (movement of the bracket 13) is gradually suppressed (bump stopper function).

The change of the spring constant of the suspension device according to the load is represented by a non-linear diagram as shown in FIG. That is, when the leaf spring 3 and the rubber 15 come into contact with each other, the spring constant is in the low spring constant region caused by the shear deformation of the rubber 14,
The region where the spring constant rises gently due to the shear deformation of No. 4 and the compression deformation of the rubber 15 and the region where the spring constant rises due to the compression deformation of the rubber 15 starting from the time when the rubber 15 and the spacer 31 abut. Change to linear.

Therefore, the rubber spring unit 1
1 makes the suspension system more compact,
The non-linear characteristic of the spring constant during loading can be obtained while reducing the cost.

In addition, since the stopper 28 is provided immediately above the bracket 13, the upward movement of the bracket 13 (excessive movement of the leaf spring 3) while utilizing the compressive deformation of the rubber 15 to reduce the applied shock. With a simple structure, it is possible to suppress an excessive stroke of the suspension device while reducing an unpleasant thrust (impact). In particular, since the distance between the bracket 13 and the bracket 13 can be adjusted by using the spacers 31 having different thickness dimensions, the stroke can be limited according to various vehicles without changing the structure of the rubber spring unit 11. . The difference in the non-linear characteristics due to the spacer 31 is indicated by a two-dot chain line in FIG. However, the two-dot chain line in FIG. 3 indicates the non-linear characteristic when the spacer 31 is not provided (the upper end of the bracket 13 is in direct contact with the lower surface wall 2a of the side frame 2).

In one embodiment, the side frame 2
A pair of front and rear brackets 21 and 23 are arranged on the lower surface of the side frame 2 to assemble the rubber spring unit according to the structure of the suspension device in which the leaf spring 3 is attached to the lower surface of the side frame 2. If the suspension device has a leaf spring 3 attached to the side surface of the side frame 2, a pair of front and rear brackets 21 and 2 are provided on the side surface of the side frame 2 in accordance with the structure of the device.
3 may be arranged and a rubber spring unit may be assembled. Further, in addition to the pair of front and rear brackets 21 and 23, for example, a pair of brackets (not shown) are provided in the vehicle width direction at positions sandwiching the intermediate bracket 13, and the brackets 13 are similarly supported by rubber using these brackets. Is also good.

In one embodiment, the present invention is applied to a truck rear suspension device. However, the present invention is not limited to this.
It is needless to say that the present invention can be applied to a suspension device of a vehicle in which nonlinear characteristics of another vehicle are required.

[0038]

As described above, according to the first aspect of the present invention, the structure of the rubber spring unit, which is prevented from protruding to the surroundings, allows the deformation of the first rubber in the shear direction,
Due to the deformation of the second rubber in the compression direction, the spring constant of the suspension device can be changed nonlinearly according to the applied load.

Therefore, the required non-linear characteristics can be obtained with the structure of the suspension device which is excellent in compactness and cost reduction.

According to the second aspect of the present invention, in addition to the above-described effects, the excessive stroke of the suspension device can be regulated without the feeling of thrust up by utilizing the compression deformation of the second rubber. To play.

[Brief description of the drawings]

FIG. 1 is a side view showing a suspension device according to an embodiment of the present invention as a rubber spring unit of a main part.

FIG. 2 is a side view for explaining a behavior of a spring constant that changes according to a load of the rubber spring unit.

FIG. 3 is a diagram showing non-linear characteristics of a spring constant obtained by a shear deformation provided by a first rubber and a compression deformation provided by a second rubber of the rubber spring unit.

[Explanation of symbols]

2 Side frame (body) 3 Leaf spring 10 Axle (axle) 11 Rubber spring unit 13 Bracket (center bracket) 14 Rubber (first rubber) 15 Rubber (second rubber) 21 and 23 ... front side bracket, rear side bracket (a pair of front and rear support brackets) 28 ... stopper 31 ... spacer.

Claims (2)

[Claims] 1. A suspension device comprising a leaf spring that supports an axle movably up and down supported on a vehicle body and a rubber spring unit disposed between the vehicle body and the leaf spring. A pair of support brackets formed so that the spring unit is arranged at least in the vehicle body front-rear direction at a predetermined distance on the vehicle body, a center bracket disposed between the support brackets, and between the center bracket and each of the support brackets A first rubber that supports the center bracket movably up and down, and that bears a load applied to the center bracket by shearing deformation, and is attached so as to protrude from a lower surface of the center bracket, and Positioned directly above the leaf spring or the axle, Suspension device for, characterized in that it is constituted and a second rubber to bear a load applied to serial center bracket in compressive deformation. 2. The suspension device according to claim 1, wherein the rubber spring unit further includes a stopper in a vehicle body portion immediately above the center bracket.