JPH07286637A - Air spring device - Google Patents

Abstract

PURPOSE:To provide a high level control with an extremely simple and inexpensive structure by providing a pair of throttle valve devices for controlling a connecting condition between a diaphragm chamber and a lower tank chamber and varying a throttle effect between high frequency vibration and low frequency vibration. CONSTITUTION:When a diaphragm 2 is telescoped during traveling, a pressure difference is generated between a first pressure chamber 21 and a second pressure chamber 22, and a clearance 14 between each valve element 12 and a leaf valve 13 of a pair of throttle valve devices 5 is varied depending on the presence or absence of the pressure difference to adjust a spring constant and damping force of a whole air spring device 1. For example, during the traveling on a bad road, the velocity of air flowing between a diaphragm chamber 2c and a lower tank chamber 3c is too high and the throttle effect of an orifice 6a is provided, but the pressure in the first pressure chamber 21 is held as it is. Thus, because the pressure difference between the pressure chambers 21 and 22 is small, the leaf valve of large diameter only is opened, the spring constant becomes small, and soft riding comfort can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air spring device, and more particularly, to a communication state between a diaphragm chamber and a lower tank chamber by a lower tank provided below the diaphragm chamber and a throttle valve device in a cylinder provided in a central portion thereof. By changing the high frequency vibration and the low frequency vibration of the vehicle, the spring constant can be automatically changed so that a hard ride on a good road and a soft ride on a bad road can be obtained. The present invention relates to an air spring device having a very simple structure that always provides a comfortable riding comfort and good steering stability depending on road surface conditions, and does not require complicated and expensive electronic control.

[0002]

2. Description of the Related Art Conventionally, an air spring device that provides a soft ride is used in vehicles such as sightseeing buses, long-distance buses, some large trucks, and high-class passenger cars.
With a simple structure, the volume of the expandable diaphragm of the air spring device was constant, and it was impossible to change the spring constant according to the road surface condition.

Therefore, if the design is made with emphasis on riding comfort on bad roads, the spring constant on good roads will be too small and the vehicle will sway too much due to rolling or pitching, resulting in a comfortable riding comfort and good steering stability. On the contrary, if the design is made with an emphasis on riding comfort on a good road, the spring constant on a bad road is too large and there is a drawback that a comfortable ride cannot be obtained.

On the other hand, in order to eliminate such a drawback, in some high-grade air spring devices, an auxiliary tank having a specific volume is provided outside the diaphragm, and an electromagnetic valve is provided between the auxiliary tank and the diaphragm. When the solenoid valve is placed and the opening and closing of the solenoid valve is controlled by a computer, a soft ride is desired (high frequency vibration of the vehicle), the solenoid valve is opened to connect the diaphragm chamber and the auxiliary tank chamber to form an air spring. When you want to increase the volume of the vehicle and have a stable ride on the spring (when the vehicle is in low-frequency vibration)
An air spring device has been put into practical use in which the solenoid valve is closed to cut off the communication between the diaphragm chamber and the auxiliary tank chamber to reduce the volume of the air spring.

However, such a high-grade air spring device accompanied by electronic control requires a lot of considerably expensive parts such as various sensors, microcomputers, solenoid valves, actuators, etc., and has a drawback of high cost. However, there was a problem that it could only be used in high-end vehicles.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art. The object of the present invention is to extend and contract a diaphragm and to fix it to the lower part of the diaphragm. From a lower tank having a lower tank chamber having a volume smaller than that of the diaphragm chamber of the diaphragm, and a first cylinder and a second cylinder integrally provided in the central portion of the lower tank and communicating with the diaphragm chamber and the lower tank chamber. A pair of hollow cylinders, and a pair of throttle valve devices that are respectively provided in the cylinders to control the communication state between the diaphragm chamber and the lower tank chamber, and the throttle valve device is provided on the inner peripheral surface of the cylinder. A plate that is fixed and has a small diameter orifice formed in the center and a large diameter communication hole on the outer circumference, and is fixed to the plate surrounding the orifice. Leaf valve retainer, a small-diameter leaf valve held by the leaf-valve retainer, and a valve element that engages with the small-diameter leaf valve and reciprocates in the axial direction of the cylinder according to the deflection of the leaf valve. , A large-diameter leaf valve that is fixed to the inner peripheral surface of the cylinder and has a communication hole having a diameter smaller than that of the valve element formed in the center, and presses and urges the valve element toward the plate side. Are arranged in a pair of cylinders in opposite directions, and the gap between the valve body and the large-diameter leaf valve is changed depending on the case of high frequency vibration and the case of low frequency vibration. By configuring the spring constant to change by controlling the state of communication with the lower tank chamber, the volume as an air spring automatically decreases when a comfortable ride on the spring is desired, such as when driving on a good road. The spring constant is increased, and when a soft ride is desired, such as when driving on rough roads, the volume as an air spring is automatically increased to reduce the spring constant. By obtaining an excellent air spring device that can change the spring constant automatically by sensing the state of vibration from the vehicle with an inexpensive structure without using expensive components such as various sensors and computers. is there.

[0007]

SUMMARY OF THE INVENTION In summary, the present invention (claim 1) comprises an expandable diaphragm and a lower tank chamber fixed to the lower portion of the diaphragm and having a volume smaller than the volume of the diaphragm chamber of the diaphragm. A lower tank, a pair of hollow cylinders that are integrally provided in the central portion of the lower tank and that are in communication with the diaphragm chamber and the lower tank, and that are composed of a first cylinder and a second cylinder. A pair of throttle valve devices for controlling the communication state between the diaphragm chamber and the lower tank chamber, the throttle valve device being fixed to the inner peripheral surface of the cylinder and having a small diameter orifice formed in the center A plate having a large diameter communication hole formed therein, a leaf valve retainer fixed to the plate surrounding the orifice, and the leaf A small-diameter leaf valve held by the lube retainer, a valve body that engages with the small-diameter leaf valve and reciprocates in the axial direction of the cylinder according to the bending of the leaf valve, and an inner peripheral surface of the cylinder. A pair of throttle valves that are fixedly connected to each other and have a communication hole having a diameter smaller than that of the valve body and that presses and biases the valve body toward the plate. The diaphragm chamber and the lower tank chamber by changing the gap between the valve body and the large-diameter leaf valve depending on the case of high-frequency vibration and the case of low-frequency vibration. It is characterized in that it is configured to change the spring constant by controlling the communication state with.

[0008]

[Function] If the diaphragm expands or contracts while the vehicle is running,
Sometimes, the throttle valve device opens and closes the communication state between the diaphragm chamber and the lower tank chamber, and sometimes closes it. A pair of throttle valve devices arranged upside down act alternately when the diaphragm is compressed and when it is expanded.

That is, when the vibration from the road surface (vehicle body vibration) is a low frequency vibration such as rolling or pitching as when running on a good road, the flow velocity of the air entering the cylinder chamber from the diaphragm chamber is Being slow, it slowly passes through the orifice into the pressure chamber between the small diameter leaf valve and the plate.

As a result, the valve body is pushed by the small-diameter leaf valve and approaches the large-diameter leaf valve side, the gap between the large-diameter leaf valve and the valve body becomes narrow, and the diaphragm is compressed. During extension, the communication between the diaphragm chamber and the cylinder chamber and the lower tank chamber is closed, and the volume of the air spring is reduced, the spring constant is increased, the damping force is increased, and the spring comfort is stable. And good steering stability is obtained.

When the vibration from the road surface (vibration of the vehicle body) is high frequency vibration, such as when traveling on a rough road or when passing through joints,
Since the flow velocity of the air that enters the pressure chamber from the diaphragm chamber is very fast, the amount of air passing through the orifice becomes small and the throttling effect of the orifice is exerted, the pressure in the pressure chamber does not increase, and therefore the small-diameter leaf Since the valve does not bend, the valve body does not approach the large-diameter leaf valve, and as a result, the gap between the valve body and the large-diameter leaf valve becomes wide, and both when the diaphragm is compressed and when it is expanded, The communication state between the diaphragm chamber and the cylinder chamber and the lower tank chamber is opened and closed, the volume as an air spring is increased, the spring constant is decreased, and a soft riding comfort is obtained.

In this way, according to the present invention, the spring constant of the air spring can be automatically changed according to the situation of vibration from the road surface without using any expensive sensor, solenoid valve, computer or the like. Therefore, as in the case of performing high-grade control with an extremely simple and inexpensive configuration, a comfortable riding comfort and good steering stability can be obtained under all vehicle driving conditions.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. In FIG. 1, an air spring device 1 according to the present invention includes a diaphragm 2, a lower tank 3, a pair of hollow cylinders 4, and a pair of throttle valve devices 5.

In FIG. 1, a diaphragm 2 is made of a material such as rubber so that it can expand and contract, and a ceiling plate 8 formed of an iron plate or the like is fixed to the upper part of the diaphragm 2, which is a sprung member of a vehicle. That is, it is fixed to a chassis frame (not shown) or the like.

A spare tank such as a surge tank (not shown) or an air pressure source (not shown) is provided on a part of the ceiling plate 8.
An air hose 9 connected to the vehicle is connected in communication, and the bottom portion 2a is opened by a large hole 2b, and the bottom portion 2a other than this hole 2b is fixed in a confidential state to the lower tank 3 which is a part of the unsprung member of the vehicle. Has been done.

The lower tank 3 is a lower portion of the diaphragm 2,
That is, the lower tank chamber 3 fixed to the bottom 2a and having a volume smaller than that of the diaphragm chamber 2c of the diaphragm 2
c, the lower tank chamber is closed by a bottom plate 3a and is formed in a cylindrical shape.

The pair of hollow cylinders 4 is provided in the lower tank 3
It is composed of a first cylinder 41 and a second cylinder 42 that are integrally provided in the central portion of the cylinder and communicate with the diaphragm chamber 2c and the lower tank chamber 3c.
b, 42b are formed, and the lower ends 41c, 42c are open.

The pair of throttle valve devices 5 includes the first cylinder 4
The first cylinder 1 and the second cylinder 42 are provided upside down, respectively, and are configured to control the communication state between the diaphragm chamber 2c and the lower tank chamber 3c.

The throttle valve device 5 is fixed to the inner peripheral surfaces 41a, 42a of the first cylinder 41 and the second cylinder 42, and has a small diameter orifice 6a formed in the center and a large diameter communication hole 6b in the outer periphery. The formed plate 6, the leaf valve retainer 10 that is fixed to the plate 6 so as to surround the orifice 6a, the small-diameter leaf valve 11 held by the leaf valve retainer, and the small-diameter leaf valve 11 are engaged. The valve body 12 that reciprocates in the axial direction of the first cylinder 41 and the second cylinder 42 according to the bending of the leaf valve 11, the inner peripheral surfaces 41a of the first cylinder 41 and the second cylinder 42, 42a, respectively, and the valve body 1 is attached to the central portion.
A communication hole 13a having a diameter smaller than that of the valve body 1 is formed.
Large-diameter leaf valve 1 that presses 2 toward plate 6
It consists of 3.

The diameter of the orifice 6a is the same as that of the communication hole 6
It is set to about 1/30 of the diameter of b. A first pressure chamber 21 is formed between the plate 6 and the leaf valve retainer 10, and a second pressure chamber 21 is formed between the large-diameter leaf valve 13 around the valve body 12 and the plate 6. 22 is formed.

As described above, the throttle valve devices 5 having exactly the same structure are mounted in the first cylinder 41 and the second cylinder 42 in the upside-down directions, respectively, and have the same structure, but are expanded when the diaphragm 2 is compressed. It is configured to open and close alternately with time.

The gap 14 between the valve body 12 and the large-diameter leaf valve 13, that is, the flow passage area of air is changed between the high frequency vibration and the low frequency vibration to change the diaphragm chamber 2c and the lower tank chamber 3c. It is configured to change the spring constant by controlling the communication state with.

The present invention is configured as described above,
The operation will be described below. In FIG. 1, when an appropriate amount of air is supplied from the air pressure source to the diaphragm chamber 2c of the diaphragm 2 by the air hose 9, the diaphragm 2 expands and becomes a state where it can function as an air spring. Also in the lower tank chamber 3c
The throttle valve device 5 in the cylinder 42 is once opened and supplied.

As a result, when air is supplied to the diaphragm chamber 2c and the lower tank chamber 3c, there is no pressure difference between them, and the throttle valve device 5 of the second cylinder 42 is also closed to close the diaphragm chamber 2c and the lower tank chamber 3c. It becomes stable as shown in.

Then, when the vehicle starts traveling, the diaphragm 2 expands and contracts during traveling, and sometimes the first pressure chamber 2
A pressure difference occurs between the first and second pressure chambers 22, but sometimes this pressure difference does not occur. Depending on the presence or absence of this pressure difference, the gap 14 between the valve body 12 and the large-diameter leaf valve 13 changes widely and the flow passage area of air changes.

First, referring to FIG. 4, the case where the vehicle is traveling on a good road and the diaphragm 2 is compressed will be described. In the throttle valve device 5 in the first cylinder 41, the air is indicated by an arrow A. As described above, since it slowly flows into the upper surface of the large-diameter leaf valve 13 and applies pressure to the large-diameter leaf valve 13, the closing of the second valve 4 does not have any effect.
Only the throttle valve device 5 in 2 opens and operates as a throttle valve. That is, vibration from the road surface (vehicle body vibration) becomes low frequency vibration due to rolling and pitching. In this case,
Arrow A from the diaphragm chamber 2c into the second cylinder 42
As described above, the air slowly flows in, and since the flow velocity of the air is slow, the air enters the first pressure chamber 21 through the orifice 6a to increase the pressure in the first pressure chamber 21.

On the other hand, the air enters the second pressure chamber 22 through the communication hole 6b of the plate 6, increases the pressure in the second pressure chamber 22, opens the large-diameter leaf valve 13, and opens the valve body 12.
Through the gap 14 between the large-diameter leaf valve 13 and the large-diameter leaf valve 13 and flows into the lower tank chamber 3c.

At this time, the inside of the first pressure chamber 21 is in the closed state, while the inside of the second pressure chamber 22 is in communication with the lower tank chamber 3c and is in the open state, so that the second pressure chamber 2
The pressure in the first pressure chamber 21 becomes higher than the pressure in 2, and as a result, the small-diameter leaf valve 11 bends downward, lowers the valve body 12, and stops when the forces are balanced.

For this reason, the valve body 12 approaches the large-diameter leaf valve 13 and the gap 14 is narrowed, the flow passage area of the air is reduced, the throttle valve device 5 is closed, and the air spring device 1 is adjusted. Will have a smaller spring volume, a larger spring constant, and a greater damping force, resulting in stable riding comfort on the spring and good steering stability.

Referring to FIG. 5, the case where the vehicle is traveling on a good road and the diaphragm 2 expands will be described. When the diaphragm 2 expands, the diaphragm chamber 2
Since the inside of c becomes a negative pressure and the pressure in the lower tank chamber 3c becomes higher, the air in the lower tank chamber slowly enters the first cylinder 41 and the second cylinder 42 as shown by the arrow B, but Similarly, the throttle valve device 5 in the cylinder 42 is closed only because the large-diameter leaf valve 13 is pressed upward, and only the throttle valve device 5 in the first cylinder 41 is opened and throttled. Operates as a valve.

In the operation of the throttle valve device 5 in the first cylinder 41, the air slowly flows into the first pressure chamber 21 through the orifice 6a, just as when the diaphragm 2 is compressed. Therefore, the pressure in the first pressure chamber 21 rises, the valve body 12 moves upward, and the gap 14 between the valve body 12 and the large-diameter leaf valve 13 that is opened at this time is narrowed, and the air flow is reduced. The road area is reduced and the throttle valve device 5 is closed and adjusted, the volume of the air spring device 1 is reduced, the spring constant is increased, and a stable riding comfort on the spring and good steering stability are obtained.

Next, as when driving on a rough road or when passing a joint,
When the vibration from the road surface (vibration of the vehicle body) is high frequency vibration, the flow velocity of the air entering the lower tank chamber 3c from the diaphragm chamber 2c or the air entering the diaphragm chamber 2c from the lower tank chamber 3c is very high, so The amount of air passing through becomes small and the throttling effect of the orifice 6a is exerted, so that the pressure in the second pressure chamber 22 rapidly increases or decreases, whereas the pressure in the first pressure chamber 21 does not change. Since it is kept as it is, the first pressure chamber 2
The pressure difference between the first and second pressure chambers 22 is small, and therefore the valve body 12 remains stationary due to the spring force of the small-diameter leaf valve 11, and the large-diameter leaf valve due to the increase in the pressure in the second pressure chamber 22. Only 13 is opened, the gap 14 with the valve body 12 is widened, the flow passage area of air is increased, the volume of the air spring device 1 is increased, the spring constant is decreased, and a soft riding comfort is obtained.

Referring to FIG. 6, when the diaphragm 2 is compressed, air rapidly flows from the diaphragm chamber 2c into the first cylinder 41 and the second cylinder 42 as shown by the arrow C. The throttle valve device 5 in the first cylinder 41 is simply closed and does not operate as a throttle valve.

The valve body 12 of the throttle valve device 5 in the second cylinder 42 is stationary, and the large-diameter leaf valve 13 is provided.
Only the air is flexed and the air rapidly enters the second pressure chamber 22 through the communication hole 6b as shown by the arrow C, and further the lower tank chamber 3c.
Flows in.

Therefore, the gap 14 is widened, the flow passage area of air is increased, the throttling effect is reduced, the throttle valve device 5 is opened and closed, the volume of the air spring device 1 is increased, and the spring constant is increased. It is smaller and gives a softer ride.

Referring to FIG. 7, when the diaphragm 2 is extended, air rapidly flows from the lower tank chamber 3c into the first cylinder 41 and the second cylinder 42 as shown by the arrow D. The throttle valve device 5 in the second cylinder 42 is simply closed and does not operate as a throttle valve.

The valve body 12 of the throttle valve device 5 in the first cylinder 41 is stationary, and the leaf valve 13 having a large diameter is used.
Only the air is bent and the air rapidly enters the second pressure chamber 22 through the communication hole 6b as shown by the arrow D, and further the diaphragm chamber 2
flows into c.

Therefore, the gap 14 is widened, the flow passage area of air is increased, the throttling effect is reduced, the throttle valve device 5 is opened and closed, the volume of the air spring device 1 is increased, and the spring constant is increased. It is smaller and gives a softer ride.

As described above, in the air spring device 1 of the present invention, the spring constant of the air spring is automatically changed according to the vibration condition from the road surface without using any expensive sensor, solenoid valve, computer or the like. Therefore, it is possible to obtain a comfortable ride under all vehicle driving conditions, as in the case of performing high-grade control with an extremely simple and inexpensive structure.

[0040]

As described above, the present invention is capable of expanding and contracting a diaphragm, a lower tank having a lower tank chamber fixed to the lower portion of the diaphragm and having a volume smaller than the volume of the diaphragm chamber of the diaphragm, and the center of the lower tank. Between the diaphragm chamber and the lower tank chamber, and a pair of hollow cylinders composed of a first cylinder and a second cylinder which are integrally provided in the section and communicate with the diaphragm chamber and the lower tank chamber. A pair of throttle valve devices for controlling the communication state, the throttle valve device being fixed to the inner peripheral surface of the cylinder, a plate having a small diameter orifice formed in the central portion and a large diameter communication hole formed on the outer peripheral surface; A leaf valve retainer fixed to the plate surrounding the orifice, a small-diameter leaf valve retained by the leaf valve retainer, A valve element that engages with a leaf valve of a large diameter and reciprocates in the axial direction of the cylinder according to the bending of the leaf valve, and a communication hole that is fixed to the inner peripheral surface of the cylinder and has a diameter smaller than that of the valve element in the center. Formed of a large-diameter leaf valve that presses and urges the valve element toward the plate side, and the pair of throttle valve devices are arranged in opposite directions in a pair of cylinders. In the case of frequency vibration, the gap between the valve body and the large-diameter leaf valve is changed to control the communication state between the diaphragm chamber and the lower tank chamber to change the spring constant. When you want a comfortable ride with a stable spring like when driving on the road, the volume as an air spring automatically decreases and the spring constant increases, and when you want a soft ride like when driving on a bad road The volume can be automatically increased and the spring constant can be reduced. As a result, the vehicle can be configured with a low-cost configuration without using expensive parts such as solenoid valves, various sensors, and computers. There is an effect that it is possible to obtain an excellent air spring device that can automatically change the spring constant by sensing the vibration state of the.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of an air spring device.

FIG. 2 is a cross-sectional view taken along the line II of FIG.

FIG. 3 is an enlarged vertical sectional view of a pair of throttle valve devices mounted in a pair of cylinders.

4 to 7 show the operation of the throttle valve device, and FIG.
FIG. 4 is a vertical cross-sectional view showing a compressed state of a diaphragm in the case of low frequency vibration.

FIG. 5 is a longitudinal sectional view showing a stretched state of the diaphragm in the case of low frequency vibration.

FIG. 6 is a longitudinal sectional view showing a compressed state of the diaphragm in the case of high frequency vibration.

FIG. 7 is a longitudinal sectional view showing a stretched state of the diaphragm in the case of high frequency vibration.

[Explanation of symbols]

 1 Air Spring Device 2 Diaphragm 2c Diaphragm Chamber 3 Lower Tank 3c Lower Tank Chamber 4 Cylinder 5 Throttle Valve Device 6 Plate 6a Orifice 6b Communication Hole 10 Leaf Valve Presser 11 Small Diameter Leaf Valve 12 Valve Body 13 Large Diameter Leaf Valve 13a Large Diameter Communication Hole 14 Gap 41 First cylinder 41a Inner peripheral surface 42 Second cylinder 42a Inner peripheral surface

Claims (1)

[Claims] 1. A lower tank having an expandable and contractible diaphragm, a lower tank chamber fixed to a lower portion of the diaphragm and having a volume smaller than that of the diaphragm chamber of the diaphragm, and integrally provided in a central portion of the lower tank. A pair of hollow cylinders including a first cylinder and a second cylinder that communicate with the diaphragm chamber and the lower tank chamber, and a communication state between the diaphragm chamber and the lower tank chamber that are respectively provided in the cylinders. A pair of throttle valve devices for controlling, the throttle valve device is fixed to the inner peripheral surface of the cylinder, a plate having a small diameter orifice formed in the central portion and a large diameter communication hole formed in the outer periphery,
A leaf valve retainer fixed to the plate surrounding the orifice, a small-diameter leaf valve held by the leaf valve retainer, and the cylinder that is engaged with the small-diameter leaf valve and flexes the leaf valve. And a valve body that reciprocates in the axial direction of the cylinder and a communication hole that is fixed to the inner peripheral surface of the cylinder and has a diameter smaller than that of the valve body at the center, and has a large diameter that presses the valve body toward the plate side. And a pair of throttle valve devices arranged upside down in the pair of cylinders, and the valve element and the large diameter valve are used for high frequency vibration and low frequency vibration. An air spring device, wherein a spring constant is changed by controlling a communication state between the diaphragm chamber and the lower tank chamber by changing a gap between the leaf valve and the leaf valve.