JPS5996010A - Automobile suspension - Google Patents

Abstract

PURPOSE:To prevent a vehicle from abruptly changing its vehicle height, in a suspension in which fluid chambers in left and right suspension mechanisms are communicated with an accumulator through a shut-off valve, by communicating between each fluid chamber and the accumulator through an orifice which bypasses the shut-off valve. CONSTITUTION:First chambers 2a, 2b in left and right suspension mechanisms 1a, 1b are communicated with a second fluid chamber 3 which is an accumulator charged therein with compressed air through left and right communicating passages 4a, 4b which are independent from each other, and a solenoid type shut-off valve 5 for simultaneously controlling both passages 4a, 4b to open and close the latter, is disposed in the middle section of the passages 4a, 4b. This shut-off valve 5 is normally set in its normal position A where both passages 4a, 4b are simultaneously opened. Meanwhile, it is set in its off-set position B upon, for example, cornering, where both passages 4a, 4b are simultaneously closed. Further, all fluid chambers 2a, 2b, 3 are connected together through bypass circuits provided with orifices 18a, 18b, bypassing the above-mentioned valve 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automobile suspension, and more particularly to an improvement in a fluid suspension that utilizes the compressive elasticity of gases such as air.

Conventionally, as this type of fluid suspension, as disclosed in Japanese Patent Application Laid-Open No. 50-100469, each suspension mechanism in a two-wheeled vehicle has a system in which the volume changes with the vertical displacement of the vehicle body and wheels. @1 air chamber and 2nd air chamber that always maintains a constant volume.
By providing different types of air chambers and communicating the above two types of air chambers during normal times, a low spring constant is obtained and a soft state with improved riding comfort is achieved, but when a high spring constant is required, such as during sudden braking, By cutting off the communication between the two chambers, a hard state is created in which the compression volume is reduced and the number of springs is increased, causing the vehicle to lean forward during sudden braking (
Some products are known to prevent nose dives. However, in this case, since two types of air chambers are provided for each suspension mechanism, when applied to a four-wheeled vehicle, the overall structure tends to become complicated.

Furthermore, as disclosed in, for example, Japanese Utility Model Application Publication No. 56-39311, it has been proposed that the second air chamber, which maintains a constant volume as described above, is shared by the left and right suspension mechanisms, thereby simplifying the overall configuration. has been done. That is, in this case, when a large load is applied to either the left or right suspension mechanism, such as when cornering (7), the communication between the shared second air chamber and each first air chamber is controlled by an on-off valve. By shutting off the first air chain of each suspension machine, the first air chain of each suspension machine is used in a closed position, eliminating left and right unclamping and preventing rolling.

However, in this conventional suspension, each air chamber of the left and right suspension mechanisms is
Because IW4 pulp is installed, if one of the opening/closing valves fails, the spring constant of the air spring in the suspension mechanism becomes uneven between the left and right sides, resulting in extremely poor ride comfort and an increase in the number of structural parts. However, it also has the disadvantage of being disadvantageous in terms of cost.

Therefore, by simultaneously switching between the communication and communication cutoff between the left and right first air chambers/chambers and the second air chamber using one opening/closing pulp, even if one of the opening/closing pulps breaks down, the spring constants on the left and right sides will remain unchanged. It may be possible to reduce costs by reducing the number of parts, rather than achieving a balance.

However, in a sit suspension system where switching between communication and communication cutoff between both air chambers is controlled using an open/close valve, when the open/close valve is closed, the communication between both air chambers is completely cut off. The following problems arise. In other words, when the on-off valve is closed and the air pressure in the second air chamber with a constant volume is changed and adjusted in the node state, the on-off valve is opened to communicate both air chambers and the state is switched to the soft state. As the vehicle moves rapidly, the height of the vehicle increases or decreases rapidly.

However, if you park on a slope in the soft mode, the center of gravity shifts and the vehicle tilts back and forth, and if you close the on-off valve and switch to the hard mode and then drive on a flat road, the vehicle will remain slumped forward or backward.

Furthermore, while driving in the hard state, the air in the first air chamber is compressed by the large load applied to the suspension.
When air leaks into the air chamber, the attitude of the vehicle body changes, and this change in attitude persists unless the air is switched to the soft state by opening/closing/opening the curl. By communicating each first air gap and the second air chain through a communication path that is separate from the regular communication path and has a large passage resistance,
Even if a pressure difference occurs between the two air chambers when the valve is closed/closed, the pressure difference is gradually resolved without affecting the overall spring characteristics,
Therefore, the purpose of this invention is to prevent sudden changes in vehicle height when changing spring characteristics and to stabilize the running posture of the vehicle body.

In order to achieve this object, the configuration of the present invention includes a first fluid chamber C7 which is provided in each of the left and right suspension mechanisms of an automobile, and whose volume changes in accordance with the vertical displacement of the vehicle body and wheels;
a second fluid chamber that always maintains a constant volume; mutually independent left and right communication passages that connect the first and second fluid chambers; an opening/closing knob that simultaneously opens and closes the left and right communication passages; The first fluid chamber and the second fluid chamber are provided with orifice means for communicating with each other by bypassing the if closing valve of each communication path, thereby opening and closing the valve. The pressure difference generated between the two fluid chambers is gradually eliminated by orifice means.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

In FIG. 1, reference numerals 4a and 1b represent left and right suspension mechanisms installed between the vehicle body and the front or rear wheels, respectively.
In b, there are sealed first fluid chambers 2a, 2 whose volumes change according to the vertical displacement of the vehicle body and wheels when the vehicle is running, etc.
b are formed, and compressed air is sealed in the six first fluid chambers 2a, 2b.

On the other hand, reference numeral 6 indicates a sealed second fluid chamber which is constituted by an accumulator and maintains a constant volume at all times, and compressed air is sealed inside the second fluid chamber. The second fluid chamber 6 and each of the first fluid chambers 2a, 2b are communicated with each other by mutually independent left and right communication passages 4a, 4b, and a communication passage 4a, One electromagnetic opening/closing pulp 5 is provided to simultaneously control opening and closing of the openings 4b. That is, the opening/closing pulp 5 is normally in the normal position (A) and simultaneously opens the communication passages 4a and 4b, allowing the second fluid chamber 6 and each of the first fluid chambers 2a and 2b to communicate with each other, so that the suspension mechanism 1a, While lowering the spring constant of 1b to create a soft state,
During cornering, the suspension mechanism 1a, 1b becomes the offset position (b) and closes the communication passages 4a, 4b at the same time, cutting off communication between the second fluid chamber 6 and each of the first fluid chambers 2a, 2b. It operates by increasing the spring constant to create a hard state.

Furthermore, the specific structure of the second fluid chamber 6 (accumulator) and the opening/closing pulp 5 will be described in detail based on FIG.
A circular recess 6 constituting the wall of the recess 6 is formed.
A pair of holes 7a and 7b are provided at the periphery of the bottom wall of the 2nd fluid chamber 6, communicating with the second fluid chamber 6, and a pair of holes 7a and 7b are provided at the central portion thereof, respectively, to communicate with the second fluid chamber 6.
through passages 8a and 3b formed in one side wall of the
A pair of holes 9a, 9b communicating with the fluid chambers 2a, 2b are opened, respectively, and the passages 8a, 8b and the hole 9a.

9b, the recess 6 (valve chamber 11), and the holes 7a, 7b constitute a part of the communication paths 4a, 4b.

A part of the fixed core 10 of the opening/closing pulp 5 is still fitted in the recess 6 in an airtight manner, and a valve chamber 11 is formed between the fixed core 10 and the recess 6. A pulp plunger 12All+ is freely penetrated and supported by the fixed core 10, and a valve body 16 that can be seated on the bottom wall of the valve chamber 11 (bottom wall of the recess 6) is formed at the tip of the pulp plunger 12. 1
6 in the central portion communicating with each of the first fluid chambers 2a, 2b.
By opening and closing the two holes 9a and 9b together, the communication path 4a
, 4b are opened and closed at the same time. On the other hand, a movable core 14 is formed at the rear end of the pulp plunger 12, and a pulp spring 15 is compressed between the movable core 14 and the fixed core 10 to bias the valve body 16 in the valve opening direction. has been done. Further, around the fixed core 10, the movable core 14 is attracted toward the fixed core 10, and the valve body 16 is closed against the urging force of the pulp spring 15.
The drive solenoid 16 is connected to a power source and a control switch (both not shown) through a lead wire 17, and the control switch is activated automatically or manually when cornering or the like. By controlling the pulp 5 to be closed by energizing the drive solenoid 16 and closing the pulp 5, the communicating paths 4a and 4b are simultaneously closed.

The passages 8a and 8b inside one side wall (accumulation wall portion) of the second fluid chamber 6 are communicated with the second fluid chamber B through orifices 18a and 18b formed in the side wall, respectively. Orifice 18a, 18
From bK, each of the first fluid chambers 2a, 2b and the second fluid chamber 6 are communicated with each other through the opening/closing pulp 5. In FIG. 2, 19 td is an air hole for replenishing and removing air from the second a body chamber 6 (accumulator).

Therefore, in the above embodiment, the left and right suspension mechanisms J structure 1 a are activated during normal driving of the own vehicle.

When lowering the spring constant of 1b to create a soft state, open the control switch to set the opening/closing pulp 5 to the open state (
Set to normal position (a)). In this state, each communication path 4
a, 4b open together to form the second fluid chamber 6 and each first fluid chamber 2a.
, 2b are in communication with each other, thereby increasing the compressed volume of the air springs in each suspension mechanism 1a, 1b and lowering the spring constant thereof, thereby improving riding comfort and the like.

On the other hand, when the spring constant of each suspension mechanism 1a, Ib is set to be high to make it hard during high-speed driving or cornering, the control switch is closed and the opening/closing pulp 5
The drive solenoid 16 is energized to bring the opening/closing pulp 5 into a closed state (offset position frame). In this state, the communication passages 4a, 4b are both closed, and the communication between the first fluid chambers 2a, 2b and the second fluid chamber 3 is substantially cut off. The compressed volume of the air spring becomes smaller and its spring constant becomes higher, so that surface 40-ring performance etc. can be improved and running stability can be improved.

In this case, one opening/closing pulp 5 provides two communication paths 4a.
, 4b are opened and closed at the same time to switch between the soft state and the hard state, so even if the opening/closing pulp 5 breaks down, the spring constants of the left and right suspension machines 45i1a and 1b will remain either high or low at the same time, resulting in imbalance. However, it is possible to reduce the number of parts and reduce costs.

In addition, each first fluid chamber 2 is provided with orifices 18a and 18b.
a, 2b bypass the on-off valve 5 and communicate with the second fluid chamber 6, so the orifice 18a,
It is possible to solve all the problems of the conventional example in which communication is not performed through 1 UB. That is, when high-pressure air is replenished into the second fluid chamber 6 in a hard state where the opening/closing pulp 5 is closed and the second fluid chamber 6 is disconnected from the first fluid chambers 2a and 2b, the second fluid chamber 6 is refilled with high pressure air. 6 and each first fluid chamber 2a
, 2b, and this pressure difference creates an air pressure difference between the
Air in the fluid chamber 6 flows through each orifice 18a.

The air flows gently into each of the first fluid chambers 2a, 2b through 18b, and finally the air pressures in both fluid chambers 2a, 2b, 3 are balanced. However, when the valve 5 is opened and the fluid chambers 2a, 2b, and 3 are completely communicated with each other, the air in the second fluid chamber 6 rapidly flows into each first fluid chamber 2.
There is no possibility that the water will flow into the sections a and 2b, thus preventing the vehicle height from rising rapidly. Also, conversely,
Even when air is removed from the second fluid chamber 6, both fluid chambers 2a, 2b are
The air pressures within 3 gradually become equal, making it possible to prevent a sudden downward change in vehicle height.

In addition, if you park on a slope in the soft state, the center of gravity will shift and the vehicle body will move, but if you switch to the hard state and start driving on a flat road, the front and rear suspensions will move as the center of gravity returns on the flat road. An air pressure difference occurs between each first fluid chamber 2a, 2b and second fluid chamber 6 in mechanisms 1a, 1bK, and this air pressure difference causes each orifice 1
8a.

Air flows through the fluid chambers 18b, and the air pressures within each of the fluid chambers 2a, 2b, and 6 become equal. As a result, the tilt of the vehicle body caused by parking on a slope is naturally corrected, the posture of the vehicle body is maintained normally, and the running posture can be stabilized.

Furthermore, while driving in the hard state, a large load acts on each suspension machine i1a, 1b due to bump movement, etc., and the air in each first fluid chamber 2a, 2b resists the closing force of the opening/closing valve 5. %2 Even if a large amount leaks into the fluid chamber 6, and the balance of air pressure between the second fluid chamber 6 and each of the first fluid chambers 2a and 2b is disrupted, resulting in a change in the posture of the vehicle body, the same procedure as above is applied. 2'1 Air pressure in both fluid chambers 2a, 2b, 3 becomes equal by passing through the aero orifices 18a, 18b in each part 1 body chamber 2a, 2bK: back in the fluid chamber 6, and the vehicle body is normal. The vehicle returns to its original position, thereby maintaining a stable running position.

In addition, in this way, the second fluid chamber 6 and each of the first fluid chambers 2a, 2b
By communicating with the orifices 18a and 18b,
There is a concern that the effect of blocking communication between the two fluid chambers 'la, 2b, and 3 by opening/closing/circulating the groove 5 when in the - mode will be reduced, but in reality, the orifice 13 with a small passage diameter a, 18 bfdEach due to the vertical displacement of the vehicle body and wheels in hard condition! <1 Since short cycle air pressure fluctuations in the fluid chambers 2a and 2b are substantially blocked, the hard state can be stably maintained without much adverse effects.

FIG. 3 shows a modified example of the orifice means (the same parts as in FIG. 2 are given the same reference numerals and detailed explanation thereof is omitted). In the above embodiment, each of the first fluid chambers 2a, 2b The second fluid chamber 6 is communicated with the second fluid chamber 6 through orifices 18a and 18b formed on one side wall of the second fluid chamber 6, respectively. A porous sheet 2 having a large number of small holes such as styrofoam resin on the surface that opens and closes the holes 9a and 9b.
0, and both fluid chambers 2a, 2 are fixed to the porous seam) 20.
It is designed to function as an orifice means for communicating between b and 3.

Therefore, even in the wood modified example, the same effects as in the above embodiment can be achieved, and in addition, the valve body 16 of the opening/closing pulp 5 can be
Since it is sufficient to simply fix the porous sheet 20 to the tip end surface of the porous sheet, there is an advantage that manufacturing can be carried out easily.

Incidentally, in the present invention, as in the above embodiment, one opening/closing pulp 5
In addition to the fluid type suspension in which the left and right communicating passages 4a and 4b, which are independent of each other, are simultaneously opened and closed, there is also a fluid type suspension in which each communication passage is opened and closed simultaneously using a total of two opening/closing pulps (conventional example). Of course, it can also be applied to those described in .

As explained above, according to the present invention, a pair of first fluid chambers on the left and right whose volume changes with the vertical displacement of the vehicle body and each wheel, and a second fluid chamber that maintains a constant volume are mutually connected to each other. In a fluid suspension for an automobile, the first fluid chamber and the second fluid chamber communicate with each other through independent left and right communication passages, and the left and right communication passages are simultaneously opened and closed by opening/closing pulp to switch the spring characteristics of each suspension mechanism. By communicating with the fluid chamber by the orifice means that bypasses the opening and closing pulp, the sudden pressure difference between each first fluid chamber and the second fluid chamber that occurs when the opening and closing pulp is closed can be suppressed by the orifice means. Since it can be resolved gradually without significantly affecting the overall spring characteristics, it is possible to prevent large changes in vehicle height when switching spring characteristics, and to stabilize the vehicle's running posture. This can contribute to the practical application of suspensions.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic overall configuration diagram, FIG. 2 is an enlarged sectional view of the main part, and FIG. 3 is a diagram equivalent to FIG. 2 showing a modification of the orifice mechanism. Ia, 1b...Suspension mechanism, 2a, 2'b゛°
゛First fluid chamber, 6...° Second fluid chamber, 4a, 4b mountain communication passage, 5... Opening/closing pulp, 11... Valve chamber, 16... Valve body, 18a, 18b... Orifice, 2o...Porous sheet.

Claims (1)

[Claims] (1) A first fluid chamber that is provided in each of the left and right suspension mechanisms of an automobile and whose volume changes with the vertical displacement of the vehicle body and wheels, a second fluid chamber that always maintains a constant volume, and each of the above-mentioned fluid chambers. ] mutually independent left and right communication passages connecting the fluid chamber and the second fluid chamber, an on-off valve that opens and closes the left and right communication passages at the same time; An automobile suspension comprising orifice means for communicating by bypassing an opening/closing pulp of a communication passage.