JPH08247196A - Air spring - Google Patents

Abstract

PURPOSE: To improve riding comfort and traveling stability by providing an energizing means for pressing a valve member to the other surface plate, and specifying the stroke limit in the slip-off direction of the valve member from an air chamber to the position in which slide-contact of the air chamber blocking part is not released. CONSTITUTION: The stroke limit in the slip-off direction of a valve member 9 is specified to the position in which slide-contact of an air chamber blocking part 10 to a through hole peripheral surface is not released in order to reliably prevent the valve member 9 from unexpectedly slipping off from an air chamber 4. The sizes in the height directions of respectively components are so determined that the sum (a) of the height from the lower end of the valve member 9 to upper end in which the valve member is to be brought in slide-contact with the through hole peripheral surface and the maximum compression height of a compression spring 15 may be larger than the height (b) from the bottom wall upper surface of a cylindrical casing 13 to the lower surface of a lower surface plate 2, and that it may be smaller than the sum (b)+(c) of the thickness (c) of the lower surface plate 2 and the height (b) in the stroke limit state of the valve member 9. Therefore the hard spring characteristic can be realized even if oscillation is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air spring suitable for being applied to railway vehicles, automobiles, etc., and particularly to soft spring characteristics under a small relative displacement of upper and lower face plates, and a large relative spring characteristic. It provides a hard spring characteristic under displacement, and reliably maintains the hard spring characteristic up to the limit position of relative displacement.

[0002]

2. Description of the Related Art For example, in many conventional air springs for railroad vehicles, the upper plate and the lower plate are connected to the upper and lower ends of a tubular flexible film body in an airtight manner. , The compressor as an example of the pressurized air supply means, and the bottom plate is configured to be connected to the auxiliary tank, respectively, the spring constant of the vertical direction of such an air spring,

[Equation 1] dA / dx: Rate of change in pressure receiving area P: Inner pressure at center height of stroke k: Polytropic index A _O : Pressure receiving area at center height of stroke V _B : Air chamber volume at center height of stroke V _t : As indicated by the auxiliary tank volume, the spring force of the air spring depends on the relative displacement of the upper and lower face plates, as it is a constant value determined by the internal pressure supplied to the tubular flexible membrane, the pressure receiving area, etc. It will change almost linearly.

Therefore, when such an air spring is applied to a railroad vehicle, for example, between a vehicle body and a bogie, it is possible to obtain excellent vibration damping performance against vertical vibration, but As the trolley passes through the curved track portion, the amount of expansion and contraction deformation of the air spring, and thus the rolling amount of the trolley, becomes too large, which impairs traveling stability and necessitates reduction of traveling speed. There was a problem. Therefore, conventionally, in order to increase the rolling rigidity of the bogie while keeping the flexibility in the vertical direction, for example,
A torsion bar spring extending horizontally in the width direction of the bogie is pivotally supported on the bogie frame, and the arm member of the torsion bar spring and the sleeper located above the bogie frame are linked by a link to prevent rolling. It has been widely practiced that an anti-rolling device that counters the restoring moment of a torsion bar spring is used together with an air spring.

[0004]

However, when a pendulum type bolsterless bogie is selected in response to the recent demand for higher speed and stabilization of the vehicle, the anti-rolling device is restricted due to the limitation of the installation space. It is extremely difficult to provide the pendulum device together with the air spring. For this reason, it is strongly desired that the air spring itself also exerts the function as an anti-rolling device.

As a result of studies to meet such requirements, the present invention effectively corrects the spring characteristics of the air spring within a large expansion and contraction deformation region for the rolling described above. The object of the present invention is to provide a spring characteristic that is sufficiently soft to improve the riding comfort on the vehicle, especially for a small range of the expansion and contraction displacement, and on the other hand, the expansion and contraction displacement. In a large amount range, by providing a stiff spring characteristic, effectively suppressing rolling of the vehicle and improving running stability,
If an anti-rolling device is not needed, in addition,
To provide an air spring that is easy to tune.

[0006]

The air spring of the present invention comprises:
The upper and lower plates are respectively airtightly connected to the upper and lower ends of the tubular flexible membrane to define an air chamber, and one of the faceplates is connected to the inside and the auxiliary of the tubular flexible membrane. A rod which is displaceable along the central axis of the through hole in the through hole when the through hole for communicating with the tank is provided and the other face plate is provided with the connecting hole to the pressurized air supply means. -Shaped valve member is provided, and an air chamber closing portion for slidingly contacting the peripheral surface of the through hole to close the through hole at each end position of the valve member that separates the through hole, and the through hole. And an air-chamber outside closing portion that abuts around the air hole to close the through hole, and an urging means for pressing the valve member against the other face plate is provided. Set the stroke limit so that the sliding contact of the closed part of the air chamber with the peripheral surface of the through hole is not released. It is those specified in.

[0007]

In this air spring, the intervals between the closed portions of the valve member are appropriately selected, and the valve member is arranged, for example, in the through hole provided in the lower plate, and the upper end of the valve member contacts the upper plate. By bringing them into contact with each other, the valve member moves in the through hole with the relative displacement of the upper and lower double-sided plates in the approaching and separating directions.
It is relatively displaced in the direction along its central axis.

In this case, the enclosed air passes through the lower plate through hole and is compared between the air spring and the auxiliary tank within a range in which the relative displacement amounts of the double-sided plates in the approaching direction and the separating direction are small. Since it can freely flow freely, the air spring provides a soft spring characteristic, and as a result, the riding comfort of the vehicle can be enhanced.

On the other hand, when the relative displacement amount of the upper and lower face plates becomes larger than a predetermined value, either one of the closing parts of the valve member that relatively displaces following the face plates closes the through hole, and the air is closed. Since the communication between the spring and the auxiliary tank is cut off, the air spring exhibits a hard spring characteristic for relative displacement exceeding the predetermined value, and therefore the rolling phenomenon accompanied by a large relative displacement of the upper and lower face plates. Is effectively prevented from occurring, resulting in excellent running stability.

Therefore, here, the anti-rolling device is selected by appropriately selecting the axial distance between the respective closed portions formed on the valve member as described above and specifying the displacement range that brings about the soft spring characteristic. It is possible to improve the riding comfort of the vehicle and the traveling stability of the vehicle at a high level without specially installing the vehicle, and to tune the air spring extremely easily.

Here, the contact surface of the upper end of the valve member with the upper surface plate is formed into a spherical surface or other curved surface shape to make the contact area sufficiently small, and more preferably, the valve member and its contact surface are formed. When at least one of them is made of a material having a small friction coefficient, it is possible to effectively prevent the valve member from moving along with the horizontal relative displacement of the upper and lower face plates.

Further, here, the stroke limit of the valve member in the direction of coming out of the air chamber is specified at the position where the sliding contact with the peripheral surface of the through hole of the air chamber closing part is not released, so that the air closing part is closed. It is possible to sufficiently prevent the sudden decrease of the spring constant and the sudden change of the traveling characteristics due to the complete withdrawal from the through hole, and to further improve the traveling stability.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing an embodiment of the present invention, which is a cross-sectional view in the left-right direction under a mounting posture on a vehicle. Here, for each of the upper plate 1 and the lower plate 2,
The upper and lower ends of the tubular flexible film body 3 are airtightly connected to each other to define an air chamber 4 therein, and a lower surface plate 2 thereof.
A rubber laminate 5 having a substantially cylindrical shape is attached to the bottom of the. Then, the stopper plate 5a located at the lower end of the rubber laminated body 5 is provided with a connection port portion 6 connected to an unillustrated auxiliary tank so as to project inward from the rubber laminated body 5 in a tubular shape.

Further, here, in the substantially central portion of the upper plate 1,
A connection hole 7 is provided to bring the air chamber 4 into communication with a pressurized air supply means (not shown), and the lower plate 2 is provided with a passage hole 8 to allow the air chamber 4 to communicate with the inside of the rubber laminate.

Here, in this embodiment, a rod-shaped valve member 9 having a constricted portion in the middle is disposed in the through hole 8 so as to be displaceable along the central axis of the through hole 8, and At the upper end portion of the valve member 9, there is provided an air chamber closing portion 10 which is slidably in contact with the peripheral surface of the through hole 8 to close the through hole 8, and at the lower end portion thereof, a lower surface plate around the through hole 8 is formed. An outside air chamber closing portion 11 is provided which abuts the lower surface of 2 and closes the through hole 8.
Therefore, the valve member 9 can be easily arranged in the through hole by inserting the air chamber closing portion 10 of the valve member 9 into the through hole 8 from the lower side of the lower plate 2. .

Preferably, the contact surface of the upper end of the valve member 9 with the upper surface plate 1 is formed into a spherical shape or another curved surface shape as shown in the drawing, so that the contact area between the two is sufficiently small. Preferably, in addition to the above, at least one of the mutual contact surfaces of the top plate 1 and the valve member 9 is made of a material having a small friction coefficient, whereby the horizontal relative displacement of the upper and lower face plates is made. In this case, the tailgating displacement of the valve member 9 is prevented.

Further, such a valve member 9 is
In order to press the lower surface of the upper plate 1 with a required force, the urging means 12 is attached to the lower side of the lower plate 2 here. The urging means 12 of this example is a cylindrical casing 13 with a bottom wall, which is directly fixed to the lower surface plate 2, and an inner side of the cylindrical casing 13, which is attached to the bottom wall of the cylindrical casing 13. Under a height that does not reach, the sliding guide 14 also comes in contact with the outer peripheral surface of the air-chamber outside closing part 11 and has a cylindrical shape, and the inside of the sliding guide is interposed between the closing part 11 and the casing bottom wall. Mounted compression spring 15
It can be composed of and. According to this, the valve member 9 in the through hole is allowed to smoothly move up and down in the axial direction under the action of the sliding guide 14, and due to the restoring reaction force of the compression spring 15, The lower surface of the upper plate 1 is normally pressed at a right angle.

Further, here, in order to reliably prevent the valve member 9 from accidentally coming out of the air chamber 4, the stroke limit of the valve member 9 in the coming-out direction is set to the air chamber closing portion 10.
Is specified at a position where the sliding contact with the circumferential surface of the through hole is not released.
In order to do this, in FIG. 2 shown in the stroke limit state of the valve member 9, the height from the lower end of the valve member 9 to the upper end of the sliding contact with the circumferential surface of the through hole, and the maximum compression height of the compression spring 15. Is larger than the height b from the upper surface of the bottom wall of the tubular casing 13 to the lower surface of the lower surface plate 2, while the lower surface plate 2
The dimension in the height direction of each component is determined so as to be smaller than the sum b + c of the thickness c and the height b.

By the way, the cylindrical casing 1 here
3 has an opening 16 in its peripheral wall that brings the through hole 8 provided in the lower surface plate 2 into communication with the connection port portion 6, whereby the air inside the tubular flexible film body 3 is removed. , Through hole 8, opening 1
It can flow to the auxiliary tank via 6 and the connection port 6.

The air spring constructed as described above supplies the pressurized air from the pressurized air supply means to the auxiliary air tank through the connection hole 7 and from the inside of the tubular flexible membrane 3 to the auxiliary tank. It is provided for use by setting a predetermined internal pressure up to. In this case, the upper end of the valve member 9 is constantly pressed against the upper plate 1 under the action of the biasing means 12, and the valve member 9 is
Is not only in the steady static load range to the upper side of the spring, but also in the approaching and separating directions of the upper and lower face plates 1 and 2 in relation to the preselected relative distance between the both closed portions 10 and 11, the filling internal pressure, and the like. , Even in case of small relative displacement within the specified range,
The free flow of the pressurized air to the through hole 8 is allowed.

Therefore, according to this air spring, when a small amplitude vibration within a predetermined range is input to either one of the upper and lower face plates 1 and 2, the valve member 9 also vibrates accordingly. However, in this case, since the through hole 8 is maintained in a sufficiently open state by the constricted portion of the valve member 9,
The air in the air chamber smoothly flows from the through hole 8 and the opening 16 into the auxiliary tank through the connection port portion 6, and the air in the auxiliary tank traces them in the opposite direction to smoothly flow into the air chamber. Inflow, which results in a sufficiently soft spring characteristic of the air spring.

On the other hand, when the amplitude of the input vibration is large enough to exceed the predetermined range, each closing member 1 of the valve member 9 which vibrates following the input vibration.
When 0 and 11 exceed the displacement amount within a predetermined range, the through hole 8
To block the subsequent flow of air. That is, when the amount of relative downward displacement of the upper surface plate 1 with respect to the lower surface plate 2 exceeds a predetermined range, the air chamber closing portion 10 is caused to enter the through hole and slidably contact the peripheral surface of the air hole closing surface 10 with the through hole peripheral surface. Then, the through hole 8 is closed, and this is continued until the upper surface plate 1 reaches its lower limit position, as shown in the partial sectional view of FIG. Therefore, the air spring is a spring that is sufficiently hard from the time when the lower end of the sliding contact of the air chamber closing portion 10 to the peripheral surface of the through hole begins to contact the peripheral surface of the through hole until the lower limit position shown in the figure is reached. Characteristics, and due to the valve member 9 coming out of the air chamber 4,
It is possible to reliably prevent a sudden change in the spring characteristics.

On the contrary, when the relative upward displacement of the upper plate 1 with respect to the lower plate 2 exceeds a predetermined range, the compression spring 15
Under the action of, the upper end surface of the air-chamber outside blocking portion 11 is brought into contact with the lower surface of the lower surface plate 2 around the through hole 8 to close the through hole 8. Therefore, even when the relative upward displacement exceeds a predetermined range, the air spring is substantially deformed under the condition that air does not flow in, and a sufficiently hard spring characteristic is provided. Will be done.

Thus, when this air spring is arranged on a bogie such as a railroad car or an automobile or between a bogie, a chassis, etc. and a vehicle body, it is excellent in ride comfort against small-amplitude vibration. For a large amplitude exceeding a predetermined range, a high restoring reaction force is generated under a hard spring characteristic to effectively suppress the rolling of the vehicle, resulting in excellent running stability. As a result, high-speed running performance can be realized.

FIG. 3 is a longitudinal sectional view showing another example of the urging means of the valve member 9, in which the upper end flange 22 of the cylindrical casing 21 with the bottom wall is lowered around the through hole 8. Face plate 2
Screwed and fixed to the cylindrical casing 21
Of the lower part of the lower plate 2
A reduced diameter portion 23 which circumscribes the closed portion 11 functions as a sliding guide for the closed portion 11 and is provided by interposing a compression spring 15 between the casing bottom wall and the valve member 9 within the reduced diameter portion. The biasing means 12 is configured.

Here, in the cylindrical casing 21, the lower surface plate through hole 8 is formed in the connection port portion 6 on the peripheral wall above the reduced diameter portion 23.
Has an opening 24 that communicates with the closed portion 11
In order to ensure a smooth sliding movement within the reduced diameter portion, the casing bottom wall has an air intake / exhaust port 25. The biasing means 12 of this example can sufficiently perform the same function as that described above, as compared with the above-described embodiment, without the need to separately provide a special sliding guide.

Incidentally, also in this urging means 12,
Similar to the above-described embodiment, in order to prevent the valve member 9 from accidentally coming out of the air chamber 4, the stroke limit of the valve member 9 in the coming-out direction is set to the circumferential surface of the through hole of the air chamber closing portion 10. Specify the position where the sliding contact is not released.

The present invention has been described above based on the illustrated example. However, instead of the above, a through hole communicating with the auxiliary tank may be provided in the upper plate, and the valve member may be arranged in the through hole. This is possible, and this also can bring about the same effects as those of the above-mentioned embodiments.

[0029]

As described above, according to the present invention, the air spring having a simple structure can be used especially under the action of the valve member having the closing portion which is disposed in the through hole of the upper or lower face plate. Soft spring characteristics for small amplitude vibration, and
Hard spring characteristics can be automatically exerted against large-amplitude vibrations, so when applying them to railway cars and automobiles, it is not necessary to install an anti-rolling device, and it is extremely easy. With such tuning, the riding comfort on the vehicle can be sufficiently improved, and the rolling resistance can be greatly improved to improve the running stability extremely effectively. Moreover, here, by specifying the stroke limit of the valve member in the direction of withdrawing from the air chamber to a position where the sliding contact with the circumferential surface of the through hole of the air chamber closing portion is not released, no matter how large the amplitude becomes. Therefore, it is possible to surely realize the hard spring characteristic and to further improve the running stability.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing a lower limit position of a top plate.

FIG. 3 is a vertical cross-sectional view showing another example of the valve member urging means.

[Explanation of symbols]

 1 Upper Plate 2 Lower Plate 3 Cylindrical Flexible Membrane 4 Air Chamber 5 Rubber Laminate 5a Stopper Plate 6 Connection Port 7 Connection Hole 8 Through Hole 9 Valve Member 10, 11 Closure 12 Energizing Means 13, 21 Cylindrical Casing 14 Sliding guide 15 Compression springs 16, 24 Opening 22 Upper flange 23 Reduced diameter portion 25 Air intake / exhaust port a Sum b Height c Thickness

Claims (1)

[Claims] 1. An air chamber is defined by upper and lower face plates and a tubular flexible film body whose ends are airtightly connected to these double face plates, and one of the face plates has a tubular flexible membrane. An air spring having a through hole for communicating between the inside of the film body and the auxiliary tank, wherein a rod-shaped valve member displaceable along the central axis of the through hole is provided in the through hole. , At each position of the valve member that separates the through hole, an air chamber closing portion that slidably contacts the peripheral surface of the through hole to close the through hole, and abuts around the through hole to close the through hole. With the air-chamber outside closed portion to be closed, respectively, a biasing means for pressing the valve member against the other face plate is provided, the stroke limit of the valve member in the direction of withdrawing from the air chamber, the air-chamber closed portion, An air spring specified at a position where sliding contact with the peripheral surface of the through hole is not released.