JP2001122161A - Cab suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a spring constant in the back-and-forth direction of a cab with a simple structure of a link lever bush, and to keep a damping effect to a shock load high. SOLUTION: In this cab suspension device, the front end of a link lever is pivotally supported by a front bush provided in a chassis bracket, a vertical buffer device is disposed between the front bush and a cab side bracket, and the rear end of the link lever is pivotally supported by the cab side bracket through the link lever bush 9. The link lever bush 9 comprises a rubber elastic body 20 having oil chambers 21, 22 filled with a low-viscosity fluid, sandwiching an inner tube 10 from the front and the rear between the inner tube 10 and an outer tube 11, while the front and rear oil chambers 21, 22 communicate with each other through an orifice 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cab suspension device used for an automobile.

[0002]

2. Description of the Related Art Generally, in a car or the like in which a cab is tilted, a cab is softly and elastically supported on a chassis to improve riding comfort.

FIG. 6 and FIG. 7 show an example of a conventional cab suspension device. The cab suspension device is provided in front of left and right chassis frames 1 and 1.
A pair of chassis brackets 2 and 2 are fixedly mounted, and a front bush 3 made of a rubber elastic body is fitted on the upper end of the chassis brackets 2 and 2. A support shaft 4 is provided at the axis of the front bush 3, and the front ends of a pair of link levers 5, 5 are pivotally connected to the support shaft 4. Both ends of the cross link bar 6 are fixed between the front ends of the link levers 5 and 5.

[0004] Cab side brackets 8 are provided on the lower left and right sides of the cab 7, and link levers 5 and 5 are pivotally mounted on the rear lower portions of the cab side brackets 8. The link lever bush 9 is provided.

FIG. 8 shows an example of the link lever bush 9.
A rubber elastic body 12 is loaded between the inner cylinder 10 and the outer cylinder 11. A shaft 13 penetrated by the inner cylinder 10 is pivotally supported by the cab-side brackets 8, 8, and is linked to the outer periphery of the outer cylinder 11. The levers 5 and 5 are fitted.

A spring device 16 such as an air spring or a coil spring is provided between the seat 14 provided at the upper front end of the link levers 5 and 5 and the seat 15 provided at the lower front side of the cab side bracket 8. Further, a shock absorber 17 is provided between the support shaft 4 of the front bush 3 and the front side of the cab-side bracket 8 to form an up-down shock absorber 18.

In the cab suspension device, the cab 7 can be supported on the chassis frame 1 by being softly and resiliently displaced vertically and elastically on the chassis frame 1 when the vehicle is running, so that the riding comfort can be improved.

At this time, when the chassis frame 1 is displaced in the vertical direction due to unevenness of the road or the like, a small displacement width or a slow change in the displacement speed are softly absorbed by the spring device 16 having a low spring constant. On the other hand, the shock load, which is a sudden change, is damped and buffered by the shock absorber 17 having a high damping effect. As described above, the conventional cab suspension device can effectively buffer the fluctuation in the vertical direction.

However, in the conventional cab suspension device, the vibration in the vertical direction can be blocked by the vertical buffering device 18, but the level of the vibration in the front-back direction is insufficient, and The vibration had a rugged feeling, which had an adverse effect on ride comfort.

As a means for solving these problems, as shown in FIG. 9, a gap 19 is provided at a position before and after the inner cylinder 10 inside the rubber elastic body 12 of the link lever bush 9, and this gap 19 Attempts have been made to make the elastic body 12 easily bend in the front-rear direction, thereby reducing the spring constant in the front-rear direction and absorbing vibration in the front-rear direction.

However, as shown in FIG. 9, when a gap 19 is provided inside the rubber elastic body 12 to reduce the spring constant in the front-rear direction, the spring constant can be reduced to provide soft support. When the impact load acts on the link lever bush 9 in the front-rear direction because the strength of the link lever bush 9 in the front-rear direction decreases, the movement of the cab 7 increases and conversely, the ride quality deteriorates. There was a problem of doing it.

For this reason, the structure of the link lever bush 9 having the gap 19 as shown in FIG. 9 and the stopper device for preventing the cab 7 from moving back and forth are provided in combination or as described above. A method is conceivable in which the same structure as the spring device 16 and the shock absorber 17 of the vertical buffering device 18 is provided between the link lever 5 and the cab-side bracket 8 in the front-rear direction (horizontal direction).

[0013]

However, as described above, the structure of the link lever bush 9 having the gap 19 shown in FIG. 9 is combined with the stopper device that prevents the cab 7 from moving forward and backward. The method of providing the same, or the method of providing the same configuration as the upper and lower shock absorbers 18 in the front-rear direction between the link lever 5 and the cab-side bracket 8 has a problem that the configuration becomes complicated and the cost increases. Was.

The present invention has been made in order to solve the problems of the conventional cab suspension device, and has a simple structure of a link lever bush so that the spring constant in the front-rear direction of the cab is reduced and the cab suspension is attenuated against an impact load. It is an object of the present invention to provide a cab suspension device capable of maintaining a high effect.

[0015]

According to the present invention, a front end of a link lever is pivotally supported by a front bush provided on a chassis bracket, and a vertical shock absorber is disposed between the front bush and the cab side bracket. Wherein the rear end of the link lever is pivotally supported by a cab side bracket via a link lever bush, wherein the link lever bush sandwiches the inner cylinder between the inner cylinder and the outer cylinder. The present invention relates to a cab suspension device characterized in that an oil chamber filled with a low-viscosity fluid is provided at front and rear positions and is formed of a rubber elastic body, and the front and rear oil chambers are communicated with orifices.

According to the present invention, a front end of a link lever is pivotally supported by a front bush provided on a chassis bracket, and an up-down buffer is disposed between the front bush and a cab-side bracket. A cab suspension device in which a rear end is pivotally supported on a cab-side bracket via a link lever bush, wherein the link lever bush applies high-viscosity fluid to front and rear positions sandwiching the inner cylinder between the inner cylinder and the outer cylinder. The rubber elastic body is provided with an oil chamber to be filled, and the rubber elastic body is provided with a pressing portion protruding in the front-rear direction with respect to the oil chamber, and is deformed by a high-viscosity fluid moved by the pressing of the pressing portion. A cab suspension device comprising a thin deformable portion.

In the above means, an interconnect may be provided in the upper and lower support portions formed between the oil chambers before and after the rubber elastic body.

According to the present invention, an oil chamber filled with a low-viscosity fluid is formed before and after the inner cylinder of the rubber elastic body loaded between the inner cylinder and the outer cylinder of the link lever bush. In addition, since the front and rear oil chambers communicate with each other through the orifice, the oil chamber is formed when the displacement width when the chassis frame fluctuates in the front-rear direction is small or the displacement speed is slow. As a result, the elastic constant of the rubber elastic body in the front-rear direction is set low, and the above fluctuation can be softly absorbed by the low-viscosity fluid in the oil chamber flowing through the orifice. On the other hand, when the impact load acts in the front and rear direction of the chassis frame, the low-viscosity fluid in the oil chamber cannot flow through the orifice rapidly and in large quantities, but gradually flows. Can be secured.

Further, according to the present invention, the oil chamber which is filled with a high-viscosity fluid is provided between the inner cylinder and the outer cylinder of the link lever bush at the front and rear positions sandwiching the inner cylinder of the rubber elastic body. Since the rubber elastic body is provided with a pressing portion protruding in the front-rear direction with respect to the oil chamber and a thin-walled deformation portion, the displacement width when the chassis frame fluctuates in the front-rear direction is small. Or when the displacement speed is slow, the spring constant in the longitudinal direction of the rubber elastic body is set low by molding the oil chamber, and the high viscous fluid in the oil chamber pushed by the pressing portion is sheared. Then, by flowing to the both ends in the axial direction and deforming the thin deformed portion so as to expand, the above fluctuation can be softly absorbed. On the other hand, when the impact load acts in the front-back direction of the chassis frame, the high-viscosity fluid in the oil chamber cannot flow rapidly, but flows gradually, thereby securing a good damping effect. .

As described above, the link lever bush, which can effectively buffer the fluctuation in the front-rear direction,
By using in combination with the conventionally provided up and down shock absorber, the up and down, front and back vibration is well buffered,
The riding comfort of the cab can be greatly improved.

Further, since the interring is provided in the vertical support portion formed between the front and rear oil chambers of the rubber elastic body, the strength of the vertical support portion in the vertical direction can be increased. By increasing the spring constant ratio between the direction and the front-rear direction, the link lever bush can be prevented from being deformed in the vertical direction.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of a cab suspension device according to the present invention.
The same reference numerals are given to the same components as those described above, and the detailed description is omitted.

As shown in FIGS. 6 and 7, the rear end of the link lever 5 whose front end is pivotally supported by the chassis bracket 2 by the front bush 3 is pivoted to the cab side bracket 8 via the link lever bush 9. In the cab suspension device that is supported, the link lever bush 9 is
The configuration is as shown in FIG.

1 to 3, a rubber elastic body 20 is mounted between the inner cylinder 10 and the outer cylinder 11 of the link lever bush 9, and the rubber elastic body 20 has a front-rear position for sandwiching the inner cylinder 10. Are formed with oil chambers 21 and 22 filled with a low-viscosity fluid. In FIG. 1, the left oil chamber 21 is formed inside the rubber elastic body 20, and the right oil chamber 22 is formed along the inside of the outer cylinder 11. As the low-viscosity fluid, ordinary oil or ethylene glycol can be used. 23 in the figure
Is provided between the oil chambers 21 and 22 before and after the inner cylinder 10.
And a vertical support portion connecting the outer cylinder 11 and the outer cylinder 11 in a downward direction.

Further, a ring member 24 is provided on the inner surface of the outer cylinder 11 along the inner surface.
4 forms an orifice 25 along the inner surface of the outer cylinder 11. One of the front and rear oil chambers 21 and 22
1 communicates with the orifice 25 at a communication port 26, and the other oil chamber 22 communicates with the orifice 25 at a communication port 27.

Oil chambers 21 and 22 formed at the front and rear positions of the inner cylinder 10 by the rubber elastic body 20 and filled with a low-viscosity fluid.
Is to allow the outer cylinder 11 and the shaft 13 to be relatively softly displaced in the front-rear direction, and therefore, the shapes thereof can be various shapes. In addition, the cross-sectional area of the flow passage of the orifice 25 can be arbitrarily set according to the required size of the buffer effect obtained by reducing the movement amount of the low-viscosity fluid moving between the oil chambers 21 and 22. Further, instead of the orifice 25 formed inside the outer cylinder 11 as described above, the oil chambers 21 and 22 may be communicated with an orifice formed to pass the inner cylinder 10.

The vertical supporting portion 23 formed between the oil chambers 21 and 22 in front and behind the rubber elastic body 20 has a thin plate-like interface which is long in a direction parallel to the shaft 13 and has a required width in the circumferential direction. A ring 28 is provided.

The operation of the above embodiment will be described below.

When the link lever bush 9 having the structure shown in FIGS. 1 to 3 is applied to the link lever bush 9 of the cab suspension device shown in FIGS. 6 and 7, the spring constant of the cab 7 in the front-rear direction is reduced, and the impact is reduced. A high damping effect for loads can be maintained.

That is, the link lever bush 9 shown in FIGS. 1 to 3 is filled with a low-viscosity fluid at positions before and after the inner cylinder 10 of the rubber elastic body 20 loaded between the inner cylinder 10 and the outer cylinder 11. Since the oil chambers 21 and 22 are formed as described above and the front and rear oil chambers 21 and 22 are communicated with each other by the orifice 25, the displacement width when the chassis frame 1 fluctuates in the front-rear direction is small, When the speed is slow, the spring constant in the front-rear direction of the rubber elastic body 20 is set low by the formation of the oil chambers 21 and 22, and the low-viscosity fluid in the oil chambers 21 and 22 flows through the orifice 25. By doing so, the above fluctuation can be softly absorbed.

On the other hand, when an impact load, which is a sudden change, acts on the chassis frame 1 in the front-rear direction, the oil chamber 21,
The low-viscosity fluid 22 cannot flow through the orifice 25 rapidly and in large quantities, but flows gradually, so that a good damping effect can be secured.

Further, the oil chambers 21 before and after the rubber elastic body 20,
Since the inter-ring 28 is provided in the vertical support portion 23 formed between the vertical support portions 22, the vertical strength of the vertical support portion 23 can be increased. By setting a large constant ratio, it is possible to prevent the link lever bush 9 from being deformed in the vertical direction.

As described above, the provision of the link lever bush 9 shown in FIGS. 1 to 3 can effectively buffer the fluctuation in the front-rear direction, and can be combined with the vertical buffering device 18 shown in FIGS. Thus, vibrations in the vertical and longitudinal directions can be favorably damped, and the riding comfort of the cab 7 can be greatly improved.

FIGS. 4 and 5 show other embodiments of the link lever bush 9. FIG. The link lever bush 9 in FIGS. 4 and 5 is also filled with a high-viscosity fluid at the front and rear positions sandwiching the inner cylinder 10 by the rubber elastic body 20 loaded between the inner cylinder 10 and the outer cylinder 11. Oil chambers 29 and 30 are formed. In FIG. 4, the oil chamber 2 extends along the inside of the outer cylinder 11.
9 and 30 are formed. Silicon oil or the like can be used as the highly viscous fluid.

At this time, the rubber elastic body 20 forming the oil chambers 29, 30 is provided with a pressing portion 31 protruding in the front-rear direction with respect to the oil chambers 29, 30. A thin-walled deformed portion 34 composed of an internal groove 32 formed inside both ends and an external groove 33 provided outside is provided. The shapes of the pressing portion 31 and the thin deformable portion 34 can be various shapes other than the illustrated example.

In the embodiment shown in FIGS. 4 and 5, high viscosity fluids are filled in oil chambers 29 and 30 formed in the front and rear positions of the rubber elastic body 20 in the link lever bush 9 with the inner cylinder 10 interposed therebetween. Oil chambers 29 and 3 are provided in the rubber elastic body 20.
Since the pressing portion 31 protruding in the front-rear direction with respect to 0 and the thin deformation portion 34 are provided, the displacement width when the chassis frame 1 fluctuates in the front-rear direction is small or the displacement speed is slow. In this case, the spring constant in the front-rear direction of the rubber elastic body 20 is set low by the oil chambers 29 and 30, and the oil chamber 2 pressed by the pressing portion 31 is set.
The high-viscosity fluids 9 and 30 are sheared and flow to both ends in the axial direction and deform so as to expand the thin-walled deformation portion 34, so that the fluctuation can be softly absorbed.

On the other hand, when an impact load, which is a sudden change, acts on the chassis frame 1 in the front-rear direction, the oil chamber 29,
The 30 high-viscosity fluid cannot flow rapidly, but by flowing gradually, a good damping effect can be ensured.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0040]

According to the present invention, there is provided an oil chamber filled with a low-viscosity fluid at front and rear positions sandwiching an inner cylinder of a rubber elastic body loaded between an inner cylinder and an outer cylinder of a link lever bush. The oil chamber is formed and the front and rear oil chambers are communicated with the orifice. If the displacement width when the chassis frame fluctuates in the front-back direction is small or the displacement speed is slow, the oil chamber By forming the rubber elastic body, the spring constant in the front-rear direction of the rubber elastic body is set low, and the above-described fluctuation can be softly absorbed by the low-viscosity fluid in the oil chamber flowing through the orifice. On the other hand, when the impact load acts in the front and rear direction of the chassis frame, the low-viscosity fluid in the oil chamber cannot flow through the orifice rapidly and in large quantities, but gradually flows. Has the effect of being able to secure

Further, according to the present invention, the oil chamber which is filled with a high-viscosity fluid is provided between the inner cylinder and the outer cylinder of the link lever bush at the front and rear positions sandwiching the inner cylinder of the rubber elastic body. Since the rubber elastic body is provided with a pressing portion protruding in the front-rear direction with respect to the oil chamber and a thin-walled deformation portion, the displacement width when the chassis frame fluctuates in the front-rear direction is small. Or when the displacement speed is slow, the spring constant in the longitudinal direction of the rubber elastic body is set low by molding the oil chamber, and the high viscous fluid in the oil chamber pushed by the pressing portion is sheared. Then, by flowing to both ends in the axial direction and deforming the thin deformed portion so as to expand, there is an effect that the fluctuation can be softly absorbed. on the other hand,
If the impact load acts in the front-back direction of the chassis frame, the highly viscous fluid in the oil chamber cannot flow rapidly,
Since the fluid flows gradually, there is an effect that a good damping effect can be secured.

As described above, by using the link lever bush that can effectively buffer the fluctuation in the front-rear direction,
By using in combination with the conventionally provided up and down shock absorber, the up and down, front and back vibration is well buffered,
This has the effect of greatly improving the ride comfort of the cab.

Further, since the inter-ring is provided in the vertical support portion formed between the front and rear oil chambers of the rubber elastic body, the strength of the vertical support portion in the vertical direction can be increased. There is an effect that the spring lever ratio between the direction and the front-rear direction is increased to prevent the link lever bush from being deformed in the vertical direction.

[Brief description of the drawings]

FIG. 1 is a cut-away side view showing an embodiment of a link lever bush in a cab suspension device of the present invention.

2 is a view taken in the direction of arrows II-IIA in FIG. 1, and the upper half is a view taken in the direction of arrows II-IIB in FIG.

FIG. 3 is a view in the direction of arrows III-III in FIG. 1;

FIG. 4 is a cut-away side view showing another embodiment of the link lever bush in the cab suspension device of the present invention.

FIG. 5 is a view in the direction of arrows VV in FIG. 4;

FIG. 6 is a schematic side view showing an example of a conventional cab suspension device.

FIG. 7 is a front view of FIG. 6;

FIG. 8 is a cut-away side view showing an example of a conventional link lever bush.

FIG. 9 is a cut-away side view showing another example of a conventional link lever bush.

[Explanation of symbols]

 2 Chassis bracket 3 Front bush 5 Link lever 8 Cab side bracket 9 Link lever bush 10 Inner cylinder 11 Outer cylinder 18 Vertical buffer 20 Rubber elastic body 21,22 Oil chamber 23 Vertical support 25 Orifice 28 Interling 29,30 Oil chamber 31 Pressing part 34 Thin deformation part

Claims (3)

[Claims] 1. A front end of a link lever is pivotally supported by a front bush provided on a chassis bracket, and an up-down buffer is disposed between the front bush and a cab-side bracket, and a rear end of the link lever is provided. Is a cab suspension device pivotally supported by a cab-side bracket via a link lever bush, wherein the link lever bush fills a low-viscosity fluid in front and rear positions sandwiching the inner cylinder between the inner cylinder and the outer cylinder. 1. A cab suspension device comprising: an oil chamber provided with a rubber elastic body; and front and rear oil chambers communicated with orifices. 2. A front end of a link lever is pivotally supported by a front bush provided on a chassis bracket, and an up-down buffer is disposed between the front bush and the cab-side bracket, and a rear end of the link lever is provided. Is a cab suspension device pivotally supported on a cab-side bracket via a link lever bush, wherein the link lever bush fills a high-viscosity fluid in front and rear positions sandwiching the inner cylinder between the inner cylinder and the outer cylinder. It is formed by a rubber elastic body with an oil chamber,
A cab suspension, wherein the rubber elastic body includes a pressing portion protruding in the front-rear direction with respect to the oil chamber, and a thin-wall deforming portion deformed by a high-viscosity fluid moved by the pressing of the pressing portion. apparatus. 3. The cab suspension device according to claim 1, wherein an inter-ring is provided in an upper and lower support portion formed between the front and rear oil chambers of the rubber elastic body.