JPH10157436A - Suspension system of two-front-axle vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a decrease in traction caused by the floating of rear wheels which occurs when only the front rear wheels of a two-front-axle vehicle are on a bump on the road or when traveling on an upwardly arched road surface by providing an equalizing function between the front front axle and front rear axle of the two-front-axle vehicle for an improved following property and to enhance the driving stability and riding comfort of the two-front-axle vehicle by distributing axle load evenly to the axles. SOLUTION: A torsion bar 2 is placed between a front front axle 6 and a front rear axle 8, and a first operating arm 3 connected to the front front axle 6 via a ball joint 20 and a second operating arm 4 connected to the front rear axle 8 via a ball joint are secured, respectively, to the front 2a and rear 2b ends of the torsion bar 2 to transmit the vertical movement of either one of the front front axle 6 or the front rear axle 8 to the other axle as movement in the opposite direction by use of the torsion spring force of the torsion bar 2 to give the two front axles 6, 8 an equalizing function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension system for a front two-axle vehicle, and more particularly, to a road surface having an equalizing function between a front front axle and a front-rear axle to which the driving force of the front two-axle vehicle is not transmitted. Of the rear wheels, which are the driving wheels that occur when only the front and rear wheels ride on the convex part of the running road or when running on a road surface that is convex in an arc shape (so-called “kamaboko road surface”), The present invention relates to a suspension device for a front two-axle vehicle capable of preventing a decrease in traction due to climbing up and equally distributing an axle load to each axle to improve steering stability and ride comfort of the front two-wheel vehicle.

[0002]

2. Description of the Related Art In order to reduce the axle load of large vehicles such as buses and trucks, it is effective to increase the number of axles, and it is necessary to increase the number of axles. A front two-axle vehicle in which two front axles are provided, front front wheels and front and rear wheels are mounted on the front front axle and front and rear axle, respectively, and the load of the vehicle is shared and supported on each axle has been put to practical use. I have.

In a conventional front two-axle, a leaf spring is provided as a suspension device on each of a front axle, a front-rear axle, and a rear axle, and the front front axle, the front-rear axle, and the rear axle are each independently loaded. However, when the front and rear wheels ride on the convex part on the uneven road surface, a moment acting to lift the rear part of the front two-wheeled vehicle acts to lift the rear part, and as a result, the rear wheel The contact pressure on the road is weakened and traction is reduced.In an extreme case, a gap may be created between the road surface and the rear wheel, causing the rear wheel to spin and fail to transmit its driving force to the road surface. there were.

Further, the spring force of the leaf spring is required to reduce the spring constant in order to improve the ride comfort, while it is required to increase the spring constant in order to improve the steering stability. Ride comfort and steering stability require contradictory characteristics, and it is difficult to set a spring constant that satisfies both characteristics, and there is room for improvement.

Japanese Patent Application Laid-Open No. 8-104115 discloses a suspension system for a front two-axle vehicle. In this conventional example, the front two axles are connected by a link mechanism, and an equalizing function is provided between the two front axles. Although it is possible to prevent a decrease in traction due to the lifting of the rear wheels when the front two wheels cross over the stepped part with a time difference, the spring constant of the suspension system is always constant, and riding comfort and steering There was no function to balance stability, and there was room for improvement.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned disadvantages of the prior art, and has an object to arrange a torsion bar between a front front shaft and a front / rear shaft. A first operating arm connected to the front end of the torsion bar via a ball joint, and a second operating arm connected to the front / rear shaft via a ball joint at the rear end. Thus, the vertical motion of one of the front front shaft or the front and rear shaft can be transmitted to the other shaft as the reverse motion by using the torsion spring force of the torsion bar, and This means that the front two axes have an equalizing function, and when the front and rear wheels ride on the convex part of the road surface, or when traveling on an arc-shaped convex road surface, the front and rear axes are raised. Lower the front shaft to secure the rear wheels. And to prevent a decrease in traction due to lifting of the rear wheel is grounded to.

Another object is to provide a front front wheel,
The axle load can be evenly distributed to each axle by keeping the front and rear wheels and the rear wheel in contact with the ground at all times, so that good running stability can be maintained regardless of the road surface condition. Is to do so.

Still another object is to provide two torsion bars connected in parallel by a pair of gears meshing with each other and having the same phase in a horizontal plane through a front front shaft and a front / rear shaft via ball joints. The first working arm and the second
By fixing the operating arm, the vertical motion of one of the front front shaft and the front and rear shaft is transmitted to the other shaft as the reverse motion using the torsion spring force of the torsion bar, and an extremely compact mechanism. Thus, the front two axes can be provided with an equalizing function.

It is another object of the present invention to fix a first operating arm and a second operating arm connected to the front front axis and the front / rear axis at phases different from each other by 180 ° in a horizontal plane to a front end and a rear end of one torsion bar. Or two torsion bars connected in parallel by a pair of gears meshing with each other and connected to the front front shaft and the front / rear shaft at the same phase in a horizontal plane via ball joints, respectively. First working arm and second
By fixing the operating arm, the torsion bar is used as a spring having a small spring constant when one of the front front shaft and the front / rear shaft moves upward, and both the front front shaft and the front / rear shaft move simultaneously upward. Sometimes it is possible to use the torsion bar as a spring with a large spring constant, and when traveling on a road surface with small irregularities, the front front axis and the front and rear axis are vertically moved independently,
The suspension spring constant is reduced to improve ride comfort, and when traveling on undulating roads with large irregularities, the front and front axes and the front and rear axes are simultaneously moved up and down to increase the suspension spring constant and improve steering stability. It is to improve.

[0010]

SUMMARY OF THE INVENTION In short, the present invention (claim 1) comprises a front shaft, a rear shaft, a front front shaft, and a front and rear shaft to which a driving force for running a vehicle is transmitted from an engine. In a suspension device for a front two-axle vehicle each supported by a spring, a torsion bar disposed on a chassis between the front front shaft and the front-rear shaft in parallel with the traveling direction of the vehicle, and one end of the front end of the torsion bar. A first operating arm, the other end of which is connected to the front front shaft via a ball joint, and one end of which is fixed to the rear end of the torsion bar at a different phase from the first operating arm in a 180 ° horizontal plane. The other end is provided with a second operating arm connected to the front-rear shaft via a ball joint, and the up-down motion of the front front shaft or one of the front-rear shafts is regarded as a reverse motion, and To transmit to the shaft. Is, is characterized in that said longitudinal axis is configured as the rear wheel is grounded by the previous front axle to rise is lowered.

According to the present invention (claim 2), two front shafts, a rear shaft, a front front shaft, and a front and rear shaft, to which a driving force for running the vehicle from the engine is transmitted, are arranged and supported by springs. A suspension device for a front two-axle vehicle, a first torsion bar rotatably mounted on a chassis of the vehicle via a bearing from the front front shaft toward the front-rear shaft, and a front torsion bar from the front-rear shaft. A second torsion bar rotatably mounted on the chassis via a bearing in parallel with the first torsion bar, and a pair of the first torsion bar and the second torsion bar fixedly engaged with each other. A first operating arm having one end fixed to the front end of the first torsion bar and the other end connected to the front front shaft via a ball joint; and the same phase in the horizontal plane as the first operating arm. At one end A second operating arm fixed to a rear end of the second torsion bar and having another end connected to the front-rear shaft via a ball joint, and a vertical direction of the front front shaft or one of the front-rear shafts Is transmitted to the other shaft as the movement in the opposite direction, and when the front-rear shaft is raised, the front front shaft is lowered so that the rear wheel is configured to contact the ground. is there.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. 1 to 4, the first embodiment of the present invention is shown.
The suspension device 1 for a front two-axle vehicle according to the embodiment includes a torsion bar 2, a first operation arm 3, and a second operation arm 4.

First, the structure of the front two-axle wheel 5 will be described. In FIG. 1, the front front shaft 6, the front-rear shaft 8 and the rear shaft 9 are each rotatable about a pin 12 having one end 10a disposed on a chassis 11. The other end 10b is resiliently disposed on the chassis 11 by a leaf spring 10 mounted on one end of a link 13 rotatably disposed on the chassis 11 so as to function as a suspension. I have.

A front front wheel 14, a front and rear wheel 15, and a rear wheel 16 are rotatably mounted on the front front shaft 6, the front and rear shafts 8 and the rear shaft 9, respectively, and an engine (not shown) is mounted only on the rear wheel 16. The driving force is transmitted from the motor.

The distance between the front front wheel 14 and the rear wheel 16 is set to, for example, about 3.5 times the distance between the front front wheel 14 and the front and rear wheel 15, and the front front shaft 6, the front and rear shaft 8, and the rear The weight of the shaft acting on the shaft 9 is designed to be balanced.

The torsion bar 2 is for converting the vertical movement of one of the front front shaft 6 or the front and rear shaft 8 into the movement in the opposite direction and transmitting the movement to the other shaft, and is provided for the torsion. It is a round bar made of spring steel that has been subjected to heat treatment of quenching and tempering so as to act as a spring, and is disposed between the front front shaft 6 and the front-rear shaft 8 in parallel with the traveling direction of the front two-wheeled vehicle 5. .

The first operating arm 3 is for transmitting the vertical movement of the front front shaft 6 to the torsion bar 2, and has one end 3a fixed to the front end 2a of the torsion bar 2 and the other end 3b connected to the other end 3b. When the front front shaft 6 moves in the up-down direction, the movement is performed by the ball, and the upper end of a connecting link 18 rotatably connected to the front front shaft 6 by a ball joint 20 fixed to the front front shaft 6 by a nut 19. The torsion bar 2 is connected via the joint 20, the connecting link 18 and the first operating arm 3.
In FIG. 3, the torsion bar 2 is configured to be rotated counterclockwise or clockwise in FIG.

The second operating arm 4 is for transmitting the vertical movement of the front-rear shaft 8 to the torsion bar 2, and has one end 4a fixed to the rear end 2b of the torsion bar 2 and the other end 4b connected to the other end 4b. It is rotatably fitted to an upper end of a connection link 23 rotatably connected to a front-rear shaft 8 by a ball joint 22 fixed by a nut 21. When the front-rear shaft 8 moves up and down, the movement is performed by the ball joint 22. Bar 2 via the connecting link 23 and the second operating arm 4
In FIG. 3, the torsion bar 2 is configured to be rotated clockwise or counterclockwise in FIG.

The vertical movement of the front front shaft 6 and the front / rear shaft 8 is controlled by the torsion bar 2 via the first operating arm 3 and the second operating arm 4.
Torsion is applied to the torsion bar 2, and the torsional directions are opposite to each other, so that the reaction force of the torsion bar 2 torsion is transmitted to the other shaft.

When one of the front front shaft 6 and the front / rear shaft 8 moves up and down, the torsion bar 2 is twisted only at one end, so that the torsional spring force is small.
When both the front-front shaft 6 and the front-rear shaft 8 move up and down simultaneously, the torsion bar 2 is twisted from both ends, so that the torsional spring force acts as a large force.
In the above configuration, although not shown, the torsion bar 2 is rotatably supported by a plurality of bearings from the chassis 11, and is restrained from moving in the radial direction and the axial direction. Only torsional action and rotation are allowed.

Referring to FIGS. 7 and 8, a front two-axle suspension device 30 according to a second embodiment of the present invention includes a first torsion bar 31, a second torsion bar 32, and a pair of gears 33 (33A, 33A, 33A, 33A). 33B), the first operating arm 34,
A second operating arm 35.

The first torsion bar 31 is for transmitting the vertical movement of the front front shaft 6 to the front / rear shaft 8, and is subjected to a quenching and tempering heat treatment so as to act as a spring against torsion. The bearing 3 is a spring steel round bar which is fixed to the chassis 11 from the front front shaft 6 to the front / rear shaft 8.
6 so as to be rotatably fitted.

The second torsion bar 32 is for transmitting the vertical movement of the front-rear shaft 8 to the front front shaft 6, and similarly to the first torsion bar 31, is made of a heat-treated steel circle. It is a rod and is rotatably fitted to a bearing 38 fixed to the chassis 11 from the front-rear shaft 8 to the front front shaft 6 in parallel with the first torsion bar 31.

The pair of gears 33 includes a first torsion bar 3
This is for transmitting the rotational motion of the first or second torsion bar 32 to the other torsion bar, and is constituted by a pair of gears 33A, 33B having the same number of teeth meshing with each other. Rear end 31a
And the gear 33B is located at the front end 3 of the second torsion bar 32.
2a are fixed in a state of being engaged with each other.

The first operating arm 34 is for transmitting the vertical movement of the front front shaft 6 to the first torsion bar 31. One end 34a is provided at the front end 3 of the first torsion bar 31.
1b, the other end 34b is rotatably connected to a connecting arm 39 erected from the front front shaft 6 by a pin 40.

The second operating arm 35 is for transmitting the vertical movement of the front-rear shaft 8 to the second torsion bar 32, and has one end 35 a at the rear end 3 of the second torsion bar 32.
2b is fixed horizontally in the same phase as the first operating arm 34, and the other end 35b is rotatably connected to a connecting arm 41 erected from the front-rear shaft 8 by a pin 42.

The vertical movement of the front / front shaft 6 is transmitted to the first torsion bar 31 via the coupling arm 39 and the first operating arm 34 to impart a torsion to the first torsion bar 31, and the torsion is applied. Is converted by the pair of gears 33A and 33B into rotational movement in the opposite direction and transmitted to the second torsion bar 32. Further, the front-rear shaft 8 is moved in the opposite direction to the front front shaft 6 via the second operating arm 35 and the coupling arm 41. It is configured to move up and down.

The vertical movement of the front-rear shaft 8 is transmitted to the front front shaft 6 as a movement in a direction opposite to the vertical movement of the front-rear shaft 8 through a path completely opposite to the above-described order.

The present invention is configured as described above,
5 and 6, the operation of the first embodiment of the present invention will be described.

When the front axle 5 travels on a road surface 43 having a convex portion 43a, the convex portion 43a is
And the rear wheels 16 run over each other one after another.
5 has the most influence on the running when it rides on the convex portion 43a.

That is, when the front and rear wheels 15 ride on the convex portion 43a, a moment acts to lift the rear portion of the front axle 5, causing a phenomenon in which the rear portion is lifted up. To reduce the contact pressure of

The suspension device 1 for a front two-axle vehicle according to the present invention.
When the front and rear wheels 15 ride on the convex portion 43a, the front and rear wheels 15 move in the direction of arrow A, and the upward movement of the front and rear wheels 15 is controlled by the second operating arm 4 via the ball joint 22 and the connection link 23. And the second operating arm 4 is moved to the arrow B
The torsion bar 2 is twisted in the direction indicated by arrow C.

The torsion applied to the torsion bar 2 is transmitted to the front end 2a by the rigidity of the torsion bar 2,
The first operating arm 3 fixed to the front end 2a is rotated in the direction of arrow D to lower the front front shaft 6 connected via the connection link 18 and the ball joint 20 in the direction of arrow E, and the front front wheel 14 is securely moved. The rear wheel 16 is lowered by raising the front portion of the front axle wheel 5 by contacting the rear wheel, and the rear wheel 16 to be lifted is grounded to prevent a decrease in traction and to drive the vehicle stably.

Similarly, when the front front wheel 14 rides on the convex portion 43a, the upward movement of the front front wheel 14 is also performed via the ball joint 20, the connecting link 18 and the first operating arm 3 in the torsion bar 2. 6, the torsion bar 2 is counterclockwise twisted in FIG. 6, and further transmitted to the front and rear wheels 15 via the second operating arm 4, the connecting link 23 and the ball joint 22 to lower the front and rear wheels 15 downward. It operates to move to and touch the ground.

As described above, the front front wheel 14 or the front and rear wheels 1
5 is transmitted to the other axis through the torsion bar 2 in the opposite direction via the torsion bar 2, so that the front front wheel 14, the front and rear wheels 15, and the rear wheel 16 are always moved regardless of the condition of the road surface 43. The traction can be reliably prevented from lowering, and the axle load can be evenly distributed to each shaft to ensure stable running performance. Further, uneven wear of the tire can be prevented.

As described above, when the front front wheel 14 or the front and rear wheels 15 move up and down independently to get over the convex portion 43a with a time lag, the torsion bar 2 acts as a spring having a weak spring force, and Only 14 or the front and rear wheels 15 move up and down one after another along the convex portion 43a, so that a comfortable ride is secured.

Like a road surface 43 having a large undulation,
When an upward force acts on the front front wheel 14 and the front and rear wheels 15 at the same time, the upward movement of the front front wheel 14 is controlled by the ball joint 20, the connecting link 18, and the first operating arm 3. The torsion bar 2 is transmitted to the front end 2a and twists the torsion bar 2 counterclockwise in FIG. 6, and at the same time, the upward movement of the front and rear wheels 15 is performed via the ball joint 22, the connecting link 23 and the second operating arm 4. And acts on the torsion bar 2 to twist clockwise in FIG.

As described above, since the torsion bar 2 is twisted in different directions from each other, it acts as a spring having a strong spring force, and the stable operation performance can be secured without the chassis 11 moving up and down unnecessarily. .

In the second embodiment of the present invention, when the front and rear wheels 15 ride on the projection 43a in FIG.
Rises upward in the direction of arrow F, and the movement is transmitted to the second operating arm 35 via the coupling arm 41 to rotate the second operating arm 35 in the direction of arrow G, H
Gives directional torsion.

As a result, the gear 33B fixed to the second torsion bar 32 rotates in the direction of arrow H to rotate the gear 33A meshing in the direction of arrow I, and imparts the first torsion bar 31 with a twist in the direction of arrow I. Due to the rigidity of the first torsion bar 31, the first operating arm 34 is rotated in the direction of arrow J, and the motion is transmitted to the front front wheel 14 via the coupling arm 39 and lowered in the direction of arrow K to reduce the road surface 43. Ground.

When the front front wheel 14 rides on the convex portion 43a, each portion operates in the opposite direction to the above and lowers the front and rear wheels 15 to reliably contact the ground. There is no excessive axle load acting on a specific shaft.

In the suspension device 30 for a front two-axle vehicle according to the second embodiment, a first torsion bar 31 and a second torsion bar 32 are formed by a pair of gears 33A and 33B meshing with each other.
Is connected, the front front wheel 14 and the front and rear wheels 15 can be connected in an extremely small space, and the operation is exactly the same as that of the suspension device 1 for a front two-axle vehicle of the first embodiment.

[0043]

According to the present invention, a torsion bar is disposed between the front and front shafts and the front and rear shafts as described above, and the first actuation is connected to the front end of the torsion bar via the front front shaft and a ball joint. The arm and the second operating arm connected to the front and rear shafts via ball joints at the rear end are fixed, so that the vertical movement of one of the front and front shafts or the front and rear shafts is controlled by the torsion spring force of the torsion bar. It can be transmitted to the other axis as a reverse motion using it, and as a result, the front two axes can have an equalizing function, and when the front and rear wheels ride on the convex part of the road surface, or on When traveling on an arcuate convex road surface, the front and rear axles rise, lowering the front and front axles to ensure that the rear wheels touch the ground, preventing the reduction of traction due to the lifting of the rear wheels. is there.

Further, with the above structure, the front front wheel, the front and rear wheels, and the rear wheel are always in contact with the ground, so that the axle load can be evenly distributed to each axle. As a result, the running stability can be improved regardless of the road surface condition. There is an effect that can be maintained.

Further, the two torsion bars connected in parallel by a pair of gears meshing with each other are connected to the front front shaft and the front and rear shafts at the same phase in a horizontal plane via ball joints. The first working arm and the second working arm are fixed to each other, so that the vertical movement of one of the front front shaft and the front and rear shaft is performed in the opposite direction by using the torsion spring force of the torsion bar as the movement in the opposite direction. There is an effect that the front two axes can be provided with an equalizing function by an extremely compact mechanism for transmitting.

A first operating arm and a second operating arm connected to the front front axis and the front / rear axis at 180 ° different phases in a horizontal plane are fixed to the front end and the rear end of one torsion bar,
Or, a first working arm connected to a front front shaft and a front / rear shaft via a ball joint at the same phase in a horizontal plane to each of two torsion bars connected in parallel by a pair of gears meshing with each other. And the second operating arm is fixed, so that when one of the front front shaft and the front-rear shaft moves upward, the torsion bar is used as a spring having a small spring constant, and both the front front shaft and the front-rear shaft are simultaneously moved upward. When moving, the torsion bar has the effect of being able to be used as a spring with a large spring constant. As a result, when traveling on a road surface having small irregularities, the front and front axes and the front and rear axes are independently moved up and down, so that the spring constant of the suspension is increased. To improve ride comfort, and when traveling on a bumpy road surface with large irregularities, the front front axis and the front There is an effect that it is possible to improve the steering stability by increasing the number.

[Brief description of the drawings]

FIGS. 1 to 6 relate to a first embodiment of the present invention, and FIG. 1 is a side view showing an overall configuration of a suspension device for a front two-axle vehicle.

FIG. 2 is a perspective view of a front two-axis suspension device.

FIG. 3 is a perspective view of a main part of the suspension device.

FIG. 4 is a front view of a main part of a partial longitudinal section of the suspension device.

FIG. 5 is a side view showing an operation state of the suspension device.

FIG. 6 is an essential part perspective view showing an operation state of the suspension device.

7 to 9 relate to a second embodiment of the present invention, and FIG. 7 is a perspective view of a front biaxial suspension device.

FIG. 8 is a side view of a main part of the suspension device.

FIG. 9 is a perspective view of a main part showing an operating state of the suspension device.

[Explanation of symbols]

 Reference Signs List 1 Suspension device for front two-wheeled vehicle 2 Torsion bar 2a Front end 2b Rear end 3 First working arm 3a One end 3b Other one end 4 Second working arm 4a One end 4b Other one end 5 Front two-wheeled vehicle 6 Front front shaft 8 Front and rear shaft 9 Rear axle 10 Leaf spring as an example of spring 11 Chassis 16 Rear wheel 20 Ball joint 22 Ball joint 30 Suspension device for front two-axle wheel 31 First torsion bar 31b Front end 32 Second torsion bar 32b Rear end 33 A pair of gears 34 1 working arm 34a one end 34b other end 35 second working arm 35a one end 35b other end 36 bearing 38 bearing

Claims (2)

[Claims] 1. A front shaft which is provided with a rear shaft for transmitting a driving force for running a vehicle from an engine, and a front front shaft and a front and rear shaft which are not transmitted with the driving force, each of which is supported by a spring. In a suspension device for an axle wheel, a torsion bar disposed on a chassis between the front front shaft and the front / rear shaft in parallel with a traveling direction of the vehicle, and one end is fixed to a front end of the torsion bar, and the other end is A first working arm connected to the front front shaft via a ball joint, one end of which is fixed to the rear end of the torsion bar at a different phase from the first working arm in a 180 ° horizontal plane, and the other end of which is the front and rear shaft And a second operating arm connected via a ball joint to the front front shaft or one of the front and rear shafts, and configured to transmit a vertical motion of one of the front and rear shafts to the other shaft as a reverse motion. , The longitudinal axis rises That said front pre-suspension device of the front biaxial vehicle rear wheels by shaft is lowered is characterized by being configured to ground. 2. A front shaft which is provided with a rear shaft for transmitting a driving force for running the vehicle from the engine, and a front front shaft and a front and rear shaft which are not transmitted with the driving force, each of which is supported by a spring. In a suspension device for an axle, a first torsion bar rotatably mounted on a chassis of the vehicle via a bearing from the front front shaft to the front-rear shaft, and a first torsion bar from the front-rear shaft to the front front shaft. A second torsion bar rotatably mounted on the chassis via a bearing in parallel with the first torsion bar, and a pair of gears respectively fixed to the first torsion bar and the second torsion bar and engaged with each other. A first operating arm having one end fixed to the front end of the first torsion bar and the other end connected to the front front shaft via a ball joint; and one end having the same phase as the first operating arm in a horizontal plane. Before A second operating arm fixed to the rear end of the second torsion bar and having another end connected to the front-rear shaft via a ball joint, and a vertical direction of the front front shaft or one of the front-rear shafts. The front two shafts are configured to transmit the motion of the other shaft to the other shaft as a reverse motion, and when the front and rear shafts are raised, the front and front shafts are lowered so that the rear wheels contact the ground. Axle suspension system.