JPS6146702A - Suspension strut bar device - Google Patents

Abstract

PURPOSE:To enable the fronf and rear compliances of a suspension unit to be adjustable to enhance the drive feeling of a vehicle upon low and middle speed running, by providing a variable restrictor valve for constricting the flow of fluid charged in the other chamber and a space in a cylinder. CONSTITUTION:In a strut bar device 10, a strut bar 20 is connected to a suspension arm 14 through a carrier 16, and a cylinder 22 is divided into two spaces 26, 28 by means of a piston 24. Further, a pipe line 52 is extended between a pressure vessel 44 and the cylinder 22 to communicate a liquid chamber 50 with the other space 28 in the cylinder 22. The pipe line 52 incorporates a variable restrictor valve 54 which is actuated by an actuator 56. This actuator 56 is automatically controlled by a computer 58 which receives signals from a vehicle speed sensor, a vertical acceleration sensor, a lateral acceleration sensor, a longitudinal acceleration sensor, a front and rear acceleration sensor, a steering angle sensor, an accelerator operation sensor, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a suspension strut bar device,
In particular, it relates to a strut device for a strut or leishpone suspension.

(Prior Art) In a strut type suspension, a strut bar (or radius rod; referred to as a strut bar in this specification) is interposed between a vehicle body and a suspension arm to restrain the longitudinal movement of the suspension arm. Rubber bushings are placed at the connections between the strut bar and the vehicle body and suspension arms.
It is designed to absorb vibrations and shocks.

(Problems to be Solved by the Invention) It is preferable that the bushing has large longitudinal compliance from the viewpoint of ride comfort. On the other hand, increasing longitudinal compliance increases so-called compliance steer, which impairs maneuverability and stability, especially when turning or braking.

An object of the present invention is to provide a strut bar device that can improve ride comfort, maneuverability, and stability by adjusting the longitudinal compliance of a suspension according to driving conditions.

Another object of the present invention is to adjust the front and rear compliance and alignment of the suspension to improve ride comfort and maneuverability.
An object of the present invention is to provide a strut bar device that can improve stability.

(Means for Solving the Problem) The present invention provides a strut bar device interposed between a vehicle body and a suspension arm, the strut bar being connected to the vehicle body or suspension arm at one end and having a piston at the other end; a cylinder movably housing the piston and divided into two spaces and connected to the suspension arm or the vehicle body; a coil spring disposed in one space of the cylinder; and a cylinder filled with pressurized gas. a pressure vessel partitioned by a displaceable partition member into a chamber and a liquid chamber communicating with the other space of the cylinder; and a variable throttle that throttles the flow of the liquid filled in the other space of the cylinder and the liquid chamber. including a valve.

The present invention also provides a strut bar device interposed between a vehicle body and a suspension arm, the strut bar having one end connected to the vehicle body or the suspension arm and having a piston at the other end, and movably accommodating the piston. a cylinder divided into two spaces and connected to the suspension arm or the vehicle body; a coil spring disposed in one space of the cylinder; an air chamber filled with pressurized gas; and the other space of the cylinder. a pressure vessel partitioned by a displaceable partition member, a variable throttle valve that throttles the flow of liquid filled in the other space of the cylinder and the liquid chamber; and a hydraulic pressure generating means communicating with the space via a flow control valve.

(Example) Examples of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the strut bar device IO is interposed between the vehicle body 12 and the suspension arm 14, and restricts the longitudinal movement of the suspension arm 14. In the illustrated example, the suspension arm 14 is of a strut type double link type, and supports the rear wheel 18 via a carrier 16.

Strut bar device 1110 includes a strut bar 20 and a cylinder 22.

The strut bar 20 is connected to the suspension arm 14 via the carrier 16 at the rear end, and has a piston 2 at the front end.
It has 4. A known rubber bushing (not shown) is provided at the connection between the strut bar 20 and the carrier 16.
is installed.

The cylinder 22 movably accommodates a piston 24, which defines two spaces 26, 28. The rain space is kept liquid-tight by an oil seal 3o provided on the outer periphery of the piston 24.

A strut bar 20 projects outwardly through one end plate 32 of the cylinder 22, and a rod 34 is welded to the other end plate 33 of the cylinder 22. The cylinder 22 is connected to the vehicle body 12 by screwing a nut 38 into a pair of bushes 36 on the front and rear sides of the vehicle body 12 and a rod 34 passing through the vehicle body 12. The compliance of the bushings provided at the connection portion of the strut bar 20 with the carrier 16 and the bushings 36 is set with emphasis on maneuverability and stability.

A coil spring 40 is disposed within one space 26 of the cylinder and biases the piston 24 in a direction in which the piston 24 compresses the other space 28 . End plate 32 of cylinder 22
An air vent hole 42 is opened in the space 26 to allow air to escape into the space 26 as the piston 24 moves.

The pressure vessel 44 includes a partition member 46 and is partitioned into an air chamber 48 and a liquid chamber 50 by the partition member 46. In the illustrated example, the pressure vessel 44 is made of a spherical body, and the partition member 46 is a flexible rubber diaphragm that is bonded to the pressure vessel 44 at its peripheral edge. A piping 52 is provided that extends between the pressure vessel 44 and the cylinder 22 , and the liquid chamber 50 communicates with the other space 28 of the cylinder 22 .

The air chamber 48 is filled with pressurized gas, such as air, to constitute a gas spring, and the liquid chamber 50. The space 28 and the pipe 52 are filled with a liquid, such as oil.

As a result, the coil spring 40 and the gas spring are influenced by each other through the oil. The pressure of the air filled in the air chamber 48 is determined so that the reaction force caused by the gas spring and the reaction force caused by the coil spring are balanced when no longitudinal force is applied to the strut par 20.

A variable throttle valve 54 is incorporated into the pipe 52. This variable throttle valve 54 is a slide valve and has an orifice 55. By changing the cross-sectional area of the orifice 55 facing the piping 52, the flow of liquid in the piping 52 is throttled, generating damping forces of different magnitudes and blocking the flow. The longitudinal compliance, which is a combination of the spring force of the gas spring and the coil spring 40, the damping force of the variable throttle valve 54, and the compliance of the rubber bushing, is set with emphasis on riding comfort.

When set in this way, as the amount of throttle of the variable throttle valve 54 increases, the overall compliance becomes harder and the maneuverability and stability generally improve.

When the variable throttle valve 54 is closed, the overall longitudinal compliance is only the compliance of the rubber bushing.

The variable throttle valve 54 is actuated by an actuator 56. Actuator 56 can also be manually operated. However, as shown in the figure, it is preferable to automatically control it by a CPU, so-called computer 58.

Inputs to the computer 58 can include signals from sensors such as vehicle speed, vertical acceleration, lateral acceleration, longitudinal acceleration, steering angle, steering angular velocity, accelerator operating speed, brake operating speed, etc. For example, when the vehicle is at medium to low speeds, the vehicle is controlled to emphasize riding comfort based on the signal from the vehicle speed sensor. When turning,
Based on the signal from the steering angle sensor or lateral acceleration sensor,
Maneuverability and stability are determined by signals from the longitudinal acceleration sensor or brake operating speed sensor during braking, by signals from the longitudinal acceleration sensor or accelerator operating speed sensor during acceleration, and by signals from the vehicle speed sensor during high-speed driving. Control to emphasize.

The strut bar device 60 shown in FIG. 3 has the same basic configuration as the strut bar device IO shown in FIG.

Therefore, the same parts are shown with the same reference numerals, and detailed explanations are omitted.

The strut bar device 60 includes a hydraulic pressure generating means 62 and a flow rate control valve 64, which are inserted into a pipe 66 branched from the pipe 52. In the illustrated example, the hydraulic pressure generating means 62 is a pump, and the flow control valve 64 is controlled by a computer 68 together with the actuator 56.

Inputs to the computer 68 include, in addition to the signals from the various sensors described above, the toe angle, right stroke/dopper length,
Signals from sensors such as left strut par length can be used and the computer 68 provides targeted control. Control of longitudinal compliance during medium and low speeds, turning, braking, acceleration, and high-speed running is the same as described above.

When the vehicle is braking, accelerating, turning, etc. while driving, the rubber bushings provided on the suspension bend, causing changes in the toe of the suspension. Therefore, when signals from sensors such as vehicle speed, longitudinal acceleration, steering angle, toe angle, or strut bar device are input, the computer 68 controls the flow rate control valve 64 to transfer the pressure liquid generated by the hydraulic pressure generating means 62 to the cylinder 22. It leads to the space 28 of.

(Operation of the embodiment) When adjusting longitudinal compliance: When the vehicle is running and the variable throttle valve 54 is closed, the overall compliance of the strut bar device 10 (60) is determined only by the compliance of the rubber bushing.

When the car is running at medium to low speed, strut par 2
When a longitudinal force is applied to 0, the piston 24 in the cylinder 22
moves oil into and out of the liquid chamber 50 of the pressure vessel 44, causing the air within the air chamber 48 to expand and compress, causing the air to act as a spring. At this time, the variable throttle valve 54 is in a state where the throttle amount is zero or small, so little damping force is generated here, and the strut bar device 10 (60) as a whole exhibits soft compliance, improving riding comfort. is in a state of

When the car is running at high speed or turning,
When the vehicle is accelerating or decelerating, the variable throttle valve 54 changes the passage area, so a damping force of an arbitrary magnitude is generated, exhibiting stiff compliance, and maintaining improved maneuverability and stability. .

Adjustment of toe angle: When a signal from a sensor such as vehicle speed, longitudinal acceleration, steering angle, toe angle or strut par length is input, the computer 68 controls the flow control valve 64 and controls the hydraulic pressure generating means 6.
The pressure liquid generated at 2 is led into the space 28 of the cylinder 22. As a result, the protruding length of the strut par 20 is increased, the rear wheel 18 is toed out, and maneuverability and stability during high-speed turns are maintained in a state of being improved.

In the illustrated example, in order to achieve toe-in during braking or low-speed turning, the piping 66 is connected to the reservoir tank 70 using the switching valve 72.
A bypass circuit 74 is provided which incorporates a computer 68 to switch the switching valve 72 so that the liquid in the space 28 is returned to the reservoir tank 70. As a result, the strut par 20 is pushed into the cylinder 22 by the coil spring 40, and the rear wheel 18 is toe-in.

(Another example) The present invention can be practiced even if the suspension is of the Reispone type.

In the above example, the strut par 20 is connected to the suspension arm 14, and the cylinder 22 is connected to the vehicle body 12. Alternatively, the same effect can be achieved by connecting the strut par to the vehicle body and the cylinder to the suspension arm.

Instead of being a sphere, the pressure vessel 44 can also be a cylinder with a free piston. In this case, the partition member is a free piston, and as the free piston moves in the cylinder, the volume of the air chamber changes. In this specification, the term "displaceable partition member" includes not only flexible partition members such as diaphragms, but also movable partition members such as free pistons.

(Effects of the Invention) According to the present invention, by controlling the variable throttle valve, it is possible to adjust the longitudinal compliance of the suspension return, thereby improving the ride comfort during medium and low speed driving, and improving the ride comfort during high speed driving, turning, and acceleration. It is possible to improve maneuverability and stability during braking.

According to the present invention, by controlling the variable throttle valve and the flow rate control valve, it is possible to adjust the longitudinal compliance of the suspension as well as the 7 alignments, thereby further improving maneuverability and stability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a strut bar device according to the present invention, FIG. 2 is a plan view showing essential parts of a suspension, and FIG. 3 is a sectional view showing another example of the strut bar device. 10.60 Ni Strat Bar Device, 12: Vehicle Body, 14: Suspension Arm, 20
Nistrut bar, 22 Niji cylinder, 24: Piston,
26, 28: Space, 36: Push, 4
0: Coil spring, 44: Pressure vessel, 46: Partition member, 48: Air chamber, 5o: Liquid chamber, 54: Variable throttle valve, 56: 7 Cutuator, 62: Liquid pressure generating means, 64: Flow rate control valve, 58 , 68: Computer. Agent Patent Attorney Nobuyuki Matsunaga Figure 2

Claims (2)

[Claims] (1) A strut bar device interposed between a vehicle body and a suspension arm, which includes a strut bar connected to the vehicle body or suspension arm at one end and having a piston at the other end; A cylinder divided into two spaces and connected to the suspension arm or the vehicle body, a coil spring disposed in one space of the cylinder, and an air chamber filled with pressurized gas communicating with the other space of the cylinder. a pressure vessel partitioned by a partition member movable into a liquid chamber;
A strut bar device for a suspension, including a variable throttle valve that throttles the flow of liquid filled in the other space of the cylinder and the liquid chamber. (2) A strut bar device interposed between a vehicle body and a suspension arm, which includes a strut bar connected to the vehicle body or suspension arm at one end and having a piston at the other end; A cylinder divided into two spaces and connected to the suspension arm or the vehicle body, a coil spring disposed in one space of the cylinder, and an air chamber filled with pressurized gas communicating with the other space of the cylinder. a pressure vessel partitioned by a partition member movable into a liquid chamber;
A suspension comprising: a variable throttle valve that throttles the flow of liquid filled in the other space of the cylinder and the liquid chamber; and a hydraulic pressure generating means communicating with the other space of the cylinder via a flow control valve. Strut bar device.