JPS6045416A - Suspension for automobile - Google Patents

Abstract

PURPOSE:To make it possible to maintain an appropriate spring constant, by adding, to the coil spring, a resilient material spacer defining therein a liquid storing space, so that the space is communicated with an accumulator through a valve which is controlled in accordance with the movable load of the automobile. CONSTITUTION:In a suspension 10 provided to each wheel, a spacer 14 is added to a coil spring 12 which is disposed between a spring sheet 24 attached to a shock-absorber 22 and an upper supprt 26. The spacer 14 made of resilient materials such as, for example, rubber, etc., is formed therein with a hollow space 28, and is formed in a coil-like shape having the same pitch as that of the cil spring 12, the space 28 being filled with liquid such, as for example, oil and as well being communicated with an accumulator 16 through a pipe line into which a valve 18 is disposed. Further, in accordance with the output of a sensor 20 for detecting the load of the vehicle, a controller 40 closes the valve 18 when the vehicle load exceeds a predetermined value to increase the spring constant of the coil spring 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an automobile suspension, and more particularly to a suspension including a coil spring or an air spring provided to support a vehicle body.

(Prior art) The comfort performance of an automobile is determined by its correlation with the load capacity. In other words, when the suspension springs are made softer, the ride comfort is good when the load is small, but when the load is large, the ride comfort decreases, and the vehicle body posture changes more easily, reducing stability. . Conversely, if the suspension spring is made stiffer, the ride comfort is good when the load is large, but the ride comfort deteriorates when the load is small.

Therefore, in the past, emphasis has been placed on either ride comfort or loading conditions, generally from the viewpoint of stability, and ride comfort performance has been sacrificed.

However, there are vehicles that are equipped with vehicle height adjustment devices to suppress changes in vehicle body posture when loaded, but since these only control the height of the vehicle body using hydraulic pressure, etc., suspension The spring constant of the spring provided is constant, and does not solve the problem that ride comfort varies depending on the load.

(Object of the Invention) Therefore, the object of the present invention is to obtain an automobile suspension that can change the spring constant depending on the load and maintain ride comfort almost constant regardless of the load. .

(Structure of the Invention) The present invention relates to a coil spring provided to support a vehicle body, and a spacer disposed on the coil spring to change the spring constant of the coil spring, the spacer being formed of an elastic body and containing liquid inside. An automobile suspension comprising: a spacer that is made of metal, an accumulator that communicates with the inside of the spacer, a sensor that detects a load acting on the coil spring, and a valve that shuts off the spacer and the accumulator based on a signal from the sensor. Pertains to.

The present invention also provides an air spring having an air chamber provided to support a vehicle body, a tank having an auxiliary air chamber communicating with the air chamber provided to change the spring constant of the air spring, and an air spring provided to support the vehicle body. The present invention relates to an automobile suspension that includes a sensor that detects a load acting on a spring, and a valve that shuts off the air chamber and the auxiliary air chamber based on a signal from the sensor.

(First Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

The suspension 10 shown in FIG. 1 includes a coil spring 12,
It includes a spacer 14, an accumulator 16, and a valve 18. Suspensions 10 are provided in association with front, rear, left and right wheels (not shown), and in the illustrated example, one sensor 20 is provided to give signals to all suspensions 10.

The suspension lO is a MacPherson strut type, and includes a shock absorber 22 installed between the suspension arm and the vehicle body.
A coil spring 12 is disposed between a spring seat 24 provided in the upper support 26 and a spring seat 24 provided in the upper support 26 . Since the above configuration is well known, detailed illustrations are omitted.

As shown in FIG. 2, the spacer 14 is made of an elastic material such as rubber, and is formed in a hollow shape with a space 28 inside and in a coil shape having the same pitch as the coil spring 12. The spacer 14 has grooves 30 on the upper and lower sides, and the grooves 30
0 is fitted into the helical portion 13 of the coil spring 12 and arranged along the helical portion 13. Oil or other liquid is contained in the space 28 of the spacer 14. By allowing this liquid to enter and exit, the spacer 14 changes the effective number of turns of the coil spring 12 and changes the spring constant of the coil spring 12. To this end, the spacer 14 is formed to have a length spanning an appropriate number of turns of the coil spring, depending on the range of the spring constant to be varied.

The accumulator 16 is constructed by slidably disposing a free piston 34 inside a cylinder 32. A chamber 354i on one side of the free piston 34 is communicated with the space 28 of the spacer 14 via the piping 38, and contains the same liquid as the liquid in the space 28.

As a result, the liquid in the space 28 can enter and leave the chamber 35 1f. The chamber 36 on the other side of the free piston 34 is filled with air or other gas.

In the illustrated example, the valve 18 is an electromagnetically operated on-off valve,
It is incorporated into the piping 38 and communicates or blocks the space 28 of the spacer 14 and the accumulator 16. This valve 18 receives a signal from a sensor 20 via a controller 40 and receives a signal from a sensor 20.
When a signal is being output from 0, the controller 40 and the power supply 42 act to shut it off. The sensor 20 is, for example, a pressure switch disposed within the shock absorber 22 and detects the load of the vehicle body acting on the coil spring 12.

(Operation of the first embodiment) When the load is light such as when one person is on board, the sensor 20 does not output a signal, so the valve 18 is in an open state, and the space 28 of the spacer 14 and the accumulator 16 are in communication. . As a result, when the coil spring 12 is compressed, the liquid in the space 28 will flow towards the accumulator 16,
Due to the sufficient elastic deformation of the spacer 14, the part of the coil spring 12 that engages this spacer 14 deforms and exhibits a spring action, resulting in a standard spring constant given by the total number of turns of the coil spring 12.

Next, when you load luggage etc. on the car body and the loading capacity increases,
A signal is output from the sensor 20. This signal is transmitted to the controller 40
The signal is converted into a signal that enables the valve 18 to be actuated, and the valve 18 is actuated to shut off.

As a result, the space 28 of the spacer 14 is
When the coil spring 12 is compressed, the spacer 14 cannot be deformed. Therefore, the portion of the coil spring 12 that is engaged with the spacer 14 cannot be deformed, and the coil spring 12 cannot be deformed. 12 reduces the effective number of turns,
It comes to exhibit a large spring constant. In this way,
The spring constant can be changed depending on the load capacity.

(Second Embodiment) The suspension 50 shown in FIG. 3 includes an air spring 52, a tank 54, and a valve 56. Receive a signal.

The suspension 50 includes a shock absorber 60,
A cylindrical member 62 fixed to the piston rod 61 of the shock absorber 60, and a diaphragm 64 fixed to the cylinder 63 and the cylindrical member 62 of the shock absorber 60.
An air chamber 66 is defined by these. This air chamber 66
An air spring 52 is formed by the air filled inside.

The tank 54 includes an auxiliary air chamber 68 .
8 communicates with the air chamber 66 of the air spring 52 via a pipe 70. Since the spring constant of the air spring 52 changes depending on the volume of the air chamber, the volume of the auxiliary air chamber 68 can be determined depending on the range of the spring constant to be changed. .

In the illustrated example, the valve 56 is an electromagnetically operated on-off valve,
It is incorporated into the piping 70 to communicate or cut off the air chamber 66 and the auxiliary air chamber 68. This valve 56 receives a signal from the sensor 58 via the controller 72, and when the signal is output from the sensor 58, the valve 56 is shut off by the action of the controller 72 and the power source 74.

The suspension 50 includes a leveling valve 76 in the illustrated example. This leveling valve 76 detects changes in vehicle height and adjusts the amount of air supplied to the air chamber 66 of the air spring 52 via the air compressor 78, air dryer 80, reservoir tank 82, and pressure control valve 84. Keep vehicle height constant regardless of load.

The sensor 58 may be a pressure switch located within the shock absorber as in the previous example. However, with a single pressure switch, there is a possibility that the pressure switch opens and closes due to vibrations while the car is running, causing chattering, and that it is sufficient to judge the load when the car is stopped. For the reason, Sen, Su5
8 and controller 72 preferably have the configuration shown in FIG. 4. The illustrated sensor 58 includes three pressure switches 86.8.
7.88 and one vehicle speed sensor 90, and three pressure switches are arranged, for example, in relation to one front wheel and two rear wheels. The output from each pressure switch is connected to an amplifier 9
2 and then input to the AND circuit 94. On the other hand, the output of the vehicle speed sensor 90 is converted into a voltage by a frequency-voltage converter 96, the sign of which is inverted, and the result is input to a comparator 98.

This comparator 98 is set to 0, and the frequency -
Only when the input from the voltage converter 96 is 0, that is, when the vehicle is stopped, does the comparator 98 output a signal 1.
output.

(Operation of the second embodiment) The output signals of the AND circuit 94 and the comparator 98 are input to the drive circuit 100 consisting of a flip-flop or the like, and the valve 56 is operated based only on the state when the automobile is stopped. This state will be explained with reference to the time chart of FIG. When the automobile is stopped (A), the comparator 98 outputs signal 1. At this time, for example, when cargo is loaded (B), the AND circuit 94 outputs a signal l. As a result, the valve 56 is activated (C
), the spring constant becomes large because the air chamber 66 and the auxiliary air chamber 68 are shut off. The valve 56 is then held in this state. Therefore, even if the car is not running (D) and the signal from the comparator 98 becomes O, or if rolling occurs while the car is running (E), the signal from one of the pressure sensors 86 to 88 becomes O, and the AND circuit Even when the signal from 94 becomes O, the valve 56 is in a closed state and the spring constant of the air spring 52 is kept large.

When the car stops and the luggage is unloaded (F), the AND circuit 94
outputs a signal of 0, so the valve 56 is inactive (G)
, since the air chamber 66 and the auxiliary air chamber 68 communicate with each other,
The spring constant of the air spring 52 becomes smaller.

(Effects of the Invention) According to the present invention, a load acting on a coil spring or an air spring can be detected as a change in pressure of a shock absorber or the like, and the spring constant can be changed depending on the load amount. As a result, when the load is small, the spring constant of the suspension spring is reduced, and when the load is large, the spring constant is increased, making it possible to obtain almost the same ride quality regardless of the load. Therefore, it is particularly suitable for commercial vehicle suspensions.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a first embodiment of the suspension system according to the present invention, FIG. 2 is a partially sectional front view showing a coil spring and a spacer, and FIG. 3 is a suspension according to the present invention. An explanatory diagram showing the second embodiment, FIG. 4 is a control circuit diagram,
FIG. 5 is a time chart. 1O150; suspension eye, 12, coil spring, 14i spacer, 16, accumulator, 18.56: valve, 20.58; sensor, 28
;Space, 40.72;Controller, 52:Air spring, 54;Tank, 66;Air chamber, 68;Auxiliary air chamber. Agent Patent Attorney Nobuyuki Matsunaga 2 Figure 1 Figure 2

Claims (2)

[Claims] (1) A coil spring provided to support the vehicle body; a spacer disposed on the coil spring to change the spring constant of the coil spring; the spacer is made of an elastic body and contains a liquid; An automobile suspension comprising: an accumulator that communicates with the inside of the spacer; a sensor that detects a load acting on the coil spring; and a valve that shuts off the spacer and the accumulator based on a signal from the sensor. (2) An air spring having an air chamber is provided to support the vehicle body, and an air spring is provided to change the spring constant of the air spring. A tank having an auxiliary air chamber that communicates with the air chamber, a sensor that detects a load acting on the air spring, and a valve that shuts off the air chamber and the auxiliary air chamber based on a signal from the sensor. Automobile suspension badge.