JPS60185609A - Car suspension - Google Patents

Abstract

PURPOSE:To prevent deflection and deformation of a piston rod, by a method wherein a bending force, proportioning intensity, is exerted on a piston rod by a fluid actuator to offset a bending load. CONSTITUTION:The lower part of a cylinder 10 is mounted to the upper part of wheel retainer member 2 and 3, and the upper part of a piston rod 11 is resiliently supported to a car body 1 through the medium of a mount rubber 12 to damp vertical vibration of wheels 4L and 4R. The upper end of the rod 11 is extended upward from a surface, intended to be mounted, of the car body 1, and levers 17 and 18 are secured to extension parts 11a. A pair of hydraulic cylinder devices 19 and 20, serving as a fluid actuator which exerts a bending force on the rod 11, are mounted to the outer end of levers 17 and 18. This, even if a bending load, produced by an external force exerted on the rod 11, is varied, causes a bending force to be exerted in a direction, in which it is offset with a bending load applied by an external force, on the rod 11 by the devices 19 and 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a suspension installed in an automobile.
In particular, it relates to improvements to strut type suspensions.

(Prior Art) Conventionally, an automobile suspension has been provided with an extendable strut device having a cylinder and a piston rond. ) is elastically supported on the vehicle body via a mount rubber, and the so-called strut type is generally well known, in which the vertical vibration of the wheel is damped by the expansion and contraction of the strut device.

However, in order to avoid interference with the wheels, the above-mentioned devices normally have their central axis pointing downwards from the line of action of the external force received from the car body as a reaction force of the ground load acting on the wheels when the car is stationary. Since the piston rod is located inward in the vehicle width, a bending load acts on the piston rod due to a component of the external force in a direction perpendicular to the central axis.As a result, the piston rod undergoes flexural deformation and the piston There is a problem in that a large frictional resistance is generated at the sliding contact portion between the rod and the cylinder, and the damping function against vertical vibration of the wheel is not sufficiently exhibited.

Therefore, in order to solve this problem, the mount rubber, which is the mounting member for attaching the strut device (piston rod) to the vehicle body, was placed in a free state before the strut device was assembled (
By setting the piston rod support axis downward and outward of the vehicle width from the piston rod support axis after the strut device is installed, the restoring force of the mount rubber can reduce the bending force on the piston rod after the strut device is installed. It has been proposed that the bending force is applied to the piston rod so that the bending force and the bending load due to the external force acting on the piston rod from the vehicle body cancel each other out (see Japanese Utility Model Publication No. 57-96012).

However, in the above proposal, since a constant bending force is simply applied to the bitson rod, it is difficult to obtain a sufficient canceling effect between the bending loads. In other words, the bending load due to external force acting on the piston rod from the vehicle body is proportional to the ground load acting on the wheels, and varies depending on the loaded weight, etc. Also, the direction of action of the ground load changes when turning. This is because the direction in which the external force acts changes accordingly, and may fluctuate accordingly.

(Object of the Invention) In view of the above points, the object of the present invention is to provide a structure in which, even if the bending load due to an external force acting on the piston rod of the strut device changes with changes in the magnitude and direction of the ground load,
By arranging an appropriate means capable of applying a bending force to the piston rod according to the magnitude of the bending force so that the bending loads reliably cancel each other out, bending deformation of the piston rod is prevented and the piston rod The objective is to effectively reduce the frictional resistance at the sliding contact portion with the cylinder. i (Structure of the Invention) In order to achieve the above object, the structure of the present invention includes a pair of left and right struts that are provided for the left and right wheels, each of which has a lower portion attached to a wheel support member and an upper portion elastically supported by the vehicle body. a pair of fluid actuator devices that apply a bending force to the piston rod of each strut device; and a pair of fluid actuator devices that apply a bending force to the piston rod of each strut device; A fluid circuit communicating with the J chamber is provided.

As a result, when the ground load acts vertically upward on the wheels when traveling straight, equal internal pressure is generated in the pressure chambers of the pair of left and right strut devices, each corresponding to the magnitude of the ground load, and this internal pressure is transferred to the fluid circuit. On the other hand, when the car body is tilted in the opposite direction to the turning direction during turning, and the ground load acts on the wheels from vertically upward to the turning direction side, the strut The internal pressure in the pressure chamber of the device is generated differently on the left and right strut devices due to the tilt of the vehicle body, and the relatively high internal pressure generated in the pressure chamber of the strut device on the tilted side is transferred to the piston rod as the ground load is tilted. The bending load due to the applied external force increases in the pressure chamber of the fluid actuator device that applies bending force to the strut device on the non-inclined side (swivel side). The internal pressure is transmitted via a fluid circuit to the pressure chambers of the fluid actuator device which apply a bending force to the strut device on the inclined side where the bending load due to external force is reduced, thereby acting on the piston rod of the strut device. Even if the bending load due to external force fluctuates as the ground load changes in magnitude and acting direction, each fluid actuator device applies a bending force corresponding to the magnitude to the piston rod based on the magnitude of the internal pressure. However, it is designed to offset the bending load caused by external force.

(Effects of the Invention) Therefore, according to the present invention, even if the bending load due to an external force acting on the piston rod of the stock 1~device changes with changes in the magnitude and acting direction of the ground load, A bending nozzle corresponding to the size of the bending load is applied from the fluid actuator device to the piston rod to reliably offset the bending load, so that the sliding contact portion between the piston rod and the cylinder due to the bending deformation of the piston rod It is possible to effectively reduce the frictional resistance at the wheel, and to fully exhibit the damping function of the strut device against the vertical vibration of the wheel.

(Example) Hereinafter, practical examples of the present invention will be explained based on the drawings.
Ru.

1 and 2 show the front suspension of an automobile equipped with a hydropneumatic mechanism according to an embodiment of the present invention, in which 1 is the vehicle body, 2 and 3 are left and right wheels (front wheels >41.4R, respectively). Wheel support members 5 and 6 that freely support are suspension arms arranged in the vehicle width direction corresponding to the respective wheels 4m and 4R, and the inner ends of the respective suspension arms 5 and 6 are connected to the vehicle body. 1 frame 1
a.

1a, the outer end portions are rotatably attached to the lower portions of wheel support members 2 and 3, respectively.

7 and 8 are a pair of left and right strut devices disposed vertically inside each wheel 41.4R, and each strut device 7.8 has a pressure chamber 10a defined therein by a piston 9. The cylinder 10 is connected to the piston 9 and extends upward from the opening 10b of the cylinder 10, and the lower part of the cylinder 10 is connected to the wheel support member 2. , 3, and the upper part of the piston rod 11 is elastically supported by the vehicle body 1 via a mount rubber 12, and the expansion and contraction movement of the piston rod 11 with respect to the cylinder 10 dampens the vertical vibration of the wheels 4L and 4R. The ground load F1 or F2 acting on each wheel 4L, 4R is damped by the strut device 7°8 and suspension arm 5 corresponding to each vehicle width 4L, 4R. , 6, the vehicle body 1 is supported by reaction force F11.FI2 or F21.F2+, but each strut device 7°8
In order to avoid interference with the wheels 4L' and 4R, the center axis 9. of the left strut device 7 is aligned as shown in FIG. 3 when the vehicle is stationary. + is provided in a state in which the line of action of the reaction force Fn acting on the strut l-817 from the vehicle body 1 is located downward and inward from the line of action 2 of the reaction force Fn.

Reference numerals 13 and 14 denote a pair of left and right accumulators which are constituent members of a hydropneumatic mechanism each having a hydraulic chamber 15a and a gas chamber 15b therein. - It communicates with the pressure chamber 10a in the cylinder 10 via the hydraulic passage 16 formed in the piston rod 11 of the device 7.8, and applies a predetermined pressure to the pressure horn chamber 10a (
] By changing the reference length screw (the length when the mounting rod 11 is not extending or contracting) on the suspension foot 1-position 7.8, the vehicle height and vehicle posture can be adjusted. .

As a feature of the present invention, each of the above strut devices 7
, 8 are extended upwardly from the mounting surface of the vehicle body 1, and the respective extension portions 11a, 11a
A lever 17.18 extending in the vehicle width direction is fixed at the inner end of each lever, and a fluid actuator device for applying a bending force to the piston rod 11 is attached to the outer end of each lever 17.18. A pair of left and right hydraulic cylinder devices 1
9°20 is installed. Each hydraulic cylinder device 1
9.20 are each equipped with a cylinder 21 that is attached to the vehicle body 1 and has a pressure chamber 21a inside, and one end faces the pressure 1121a of the cylinder 21 and receives the pressure,
It is provided with a piston rod 22 whose other end (tip) extends outside the cylinder 14, and the tip of the piston rod 22 is rotatably connected to the outer ends of the respective levers 17 and 18.

In addition, the pressure chamber 21a of the left hydraulic cylinder device 19 is
is connected to the pressure v10a of the cylinder 10 of the strut device 8 through the first hydraulic conduit 23 and the hydraulic passage 16 of the screw rod 11 of the right strut device 8, while the pressure v10a of the cylinder 10 of the right hydraulic cylinder device 20 The pressure chamber 21a is communicated with the pressure chamber 10a of the cylinder 10 of the strut device 7 on the left side via the second hydraulic pipe a24 and the hydraulic passage 16 of the piston rod 11 of the left strut device 7.
These hydraulic lines 23, 24J5 and hydraulic passages 16.1
Pressure chamber 2 of one hydraulic cylinder device 19°20 by 6
A fluid circuit 25 is constructed which communicates the pressure chambers 1a to the pressure chambers 10a of the stock 1 to device 8.7 to which bending force is applied by the other hydraulic cylinder device 11f20.19.

Next, to explain the effects of the above embodiment, when traveling straight, the ground loads F+ and F2 act vertically upward on the wheels 4L and 4R as shown in FIG. Approximately equal internal pressures are generated in the pressure chambers 10a according to the magnitudes of the ground loads F+ and F2, respectively.

At this time, each of the above-mentioned strut devices 7 and 8 has its center axis 91 in the grounding direction mF+, similar to when the vehicle is in a stationary state.
, Since the reaction force FIllF+2 acting on each strut @7.8 from the vehicle body 1 with respect to F2 is located downward and inward in the vehicle width from the line of action 2, each strut attachment is applied as a component force of the reaction force Fll, F12. @7,8 piston rod 11
A lateral force perpendicular to the center axis 9 and outward in the vehicle width acts almost equally on the upper part (the position where it is attached to the vehicle body 1), and a bending load corresponding to the magnitude of ff1r+ and Fz in the grounding direction is applied to the piston rod 11. act.

On the other hand, each of the left and right hydraulic cylinder units fi
The ground loads F2. of the pressure chambers 10a of the respective strut devices 8, 7 are applied to the pressure chambers 21a of the strut devices 8, 7, respectively. Since the internal pressure corresponding to the magnitude of Fl is transmitted via the fluid circuit 25, each hydraulic cylinder device 19.20 transmits the pressure from each hydraulic cylinder device 19.20 via the lever 17.18 to each stock 1 to device 7. For the piston rod 11 of No. 8, the bending load due to the lateral force is in a direction that cancels out the bending load due to the lateral force acting on the piston rod 11 and corresponds to the magnitude of the grounding direction mF+, F2, that is, the size of the bending load due to the lateral force. A bending force corresponding to is applied.

On the other hand, when turning, for example, when turning right, the first
As shown in the figure, ground load F1. ．． F2 acts on the wheels 4m and 4R by tilting from vertically upward to the right side in the turning direction to resist centrifugal force, and also acts on the left and right strut devices 7,
Due to the inclination of the vehicle body 1, different internal pressures are generated in the pressure chambers 10a and 10a of the left and right gears 1 to 7 and 8, which is the outer side of the turn. This becomes higher than the internal pressure of the pressure chamber 10a of the right strut device 8.

At this time, the reaction force F acting on the left strut device 7
As the ground load F1 tilts to the right from vertically upward, u tilts toward the inside of the vehicle width compared to when the vehicle is at rest,
The line of action soft 2 is IJ of strut device 7! Jlzl'
In order to approach Ill IIA 9 +, the reaction force F11
As the component force of the screw 1 of the strut device 7, the hem rod 11
The horizontal saw acting on the upper part and directed outward in the vehicle width perpendicular to the central axis 91 becomes smaller, and the bending load due to the lateral force on the piston rod 11 decreases. On the other hand, the strut device 8 on the right side
Conversely, the reaction force F21 acting on the vehicle is inclined outward in the width direction of the vehicle when the vehicle is at rest, and its line of action 112 is separated by I11 from the central axis 9I of the stock 1-device 8. The lateral force acting on the upper part of the piston rod 11 of No. 8 and perpendicular to the center @ line 91 in the outward direction of the vehicle width increases,
The bending load due to the lateral force on the piston rod 11 increases.

On the other hand, the pressure chamber 21a of the hydraulic cylinder device 19 that applies bending force to the piston rod 11 of the left strut device 7 has the pressure chamber 10 of the right strut device @8.
The relatively low internal pressure of a is transmitted through the hydraulic passage 16 of the piston rod 11 of the strut device 8 and the first hydraulic conduit 23, while the hydraulic cylinder provides a bending horn to the piston rod 11 of the right strut device 8. device 20
The relatively high internal pressure of the pressure chamber 11a of the left strut device 7 is transmitted to the pressure chamber 21a of the strut device 7 via the hydraulic passage 16 of the piston rod 11 of the strut device 7 and the second hydraulic conduit 24, and thereby, Bending due to a lateral force acting on the piston rod 11 of each strut device 7, 8 from each hydraulic cylinder device 19, 20 via a respective lever 17, 18 on the basis of the magnitude of the internal pressure thereof. A bending force is applied in a direction that cancels out the load and corresponds to the magnitude of the bending load.

In this way, the bending cart due to the external force (lateral force) acting on each piston rod 11 of the pair of left and right strut devices 7 and 8 changes with the change in the magnitude and direction of the ground load, and the -b1 pair of hydraulic pressure changes. A bending force is applied from the cylinder lff119.20 to each piston rod 11 of the strut devices 7 and 8 in a direction that cancels out the bending load caused by the external force and in accordance with the magnitude thereof, thereby reliably canceling out the bending load. Therefore, it is possible to prevent the bending deformation of each piston rod 11 due to single bending, and effectively reduce the frictional resistance at the sliding contact area between the piston rod 11 and the cylinder 10, or the frontage part 10b of the cylinder 10. Therefore, the smooth expansion and contraction movement of the bisto front 11, the function of reducing the vertical vibration of the wheels 4L and 4R of the restrat devices 7 and 8, and the vehicle height adjustment function as a pytronneumatic mechanism are sufficiently ensured. I can do it.

It should be noted that the present invention is not limited to the above embodiments,
This includes various other modifications.

For example, in the embodiments described above, the present invention is applied to the front suspension of an automobile, but it goes without saying that it can be similarly applied to the rear suspension of an automobile.

In addition, when applying the present invention to both the front and rear A7 suspensions, the pressure horn chambers of one fluid actuator device are connected to struts to which bending force is applied by the other fluid fluid actuator device. The fluid circuit that communicates with the pressure chamber of the device is connected to the front suspension
In addition to providing two parallel suspensions for each rear suspension, two may be provided intersecting between the front suspension and the rear suspension.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram showing the overall structure of a front suspension of an automobile in a turning state, FIG. 2 is a partially cutaway front view showing the main parts, and FIG.
The figure is a schematic view of the left wheel side portion of the front suspension when the vehicle is at rest. 1... Vehicle body, 2.3... Wheel support member, 4L, 4R
...Wheel, 7.8...Strut device, 10a...
- Pressure chamber, 11... Piston rod, 17. '18・
... Lever, 19.20 ... Hydraulic cylinder device, 21
a... Pressure chamber, 22... Piston rod, 25...
・Fluid circuit.

Claims (2)

[Claims] (1) A pair of left and right strut devices are provided corresponding to the left and right wheels, each of which has a lower portion attached to a wheel support member and an upper portion elastically supported by the vehicle body, and applies bending force to the piston rond of each strut device. The present invention is characterized by comprising: a pair of fluid actuator devices; and a fluid circuit that communicates the pressure chambers of one fluid actuator device with the pressure chambers of a strut device to which bending force is applied by the other fluid actuator device. Automobile suspension. (2) The fluid actuator device is a hydraulic cylinder device installed in the vehicle body, and the piston rond of the hydraulic cylinder device is connected to the tip of a lever fixed to the piston rond of the strut device. )
Suspension of the automobile mentioned in section.