JPH11159554A - Gas spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly reduce a velocity until a piston abuts against a stopper to reduce it to zero by providing the stopper inside a cylinder so as to prevent the piston from moving more than a fixed distance, and throttling the opened part of a gas flowing path to mutually communicate both the sides of the piston with an orifice plate. SOLUTION: A gas flowing path 14 to axially pierce a piston 3 is provided so as to mutually communicate chambers on both the sides of the piston 3. When the piston 3 extends as far as possible to come into contact with a buffering member 6, a gap between the cylinder 2 and the piston 3 is shut off with a sealing ring 11, and a gas oil does not flow through the gas flowing path 13. A remaining gas oil therefore flows out through the gas flowing path 14, and the buffering member 6 is sufficiently compressed to stop and to butter the piston 3 without a shock. In this case, the orifice plate 5 is completely pressed between the piston 3 and the stopper 7 through the buffering member 5 to fastly stick to them for closing the gas flowing pathes 13, 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas spring, and more particularly, to a gas-sealed gas spring used for a vehicle or industrial use.

[0002]

2. Description of the Related Art Conventionally, an example of a gas spring used for a vehicle or an industry for buffering an impact is described in, for example, Japanese Utility Model Laid-Open No. 6-37639. As shown in FIG. 8 of the accompanying drawings, such a gas spring 100 includes a cylinder 102 in which gas or oil is sealed and one end of which is fixed to a fixed member 110,
A piston 103 provided reciprocally in the inside thereof, and the piston 103 provided at one end and the other end provided at a movable side member 111.
Piston rod 104 attached to the cylinder and cylinder 10
A stopper 107 provided in the cylinder 102 so as to limit the movement of the piston 103 reciprocating in the cylinder 2, and a retainer 105 provided in the piston 103.
A cushioning member 106 formed of an elastic body is provided between the cylinder and a stopper 107 fixed to the cylinder 102 for cushioning an impact at the time of extension.

[0003]

However, in such a conventional gas spring 100, the piston 1
As shown in FIG. 7, the extension speed of the extension member 03 from the most compressed state to the most extended state operates at a constant speed until it comes into contact with the buffer member 106, and after the contact with the buffer member 106, the speed is constant. Is reduced, and the speed becomes zero when the cushioning member 106 is fully contracted.

Here, as is apparent from FIG. 7, when the piston 103 comes into contact with the cushioning member 106 (contact point S).
For example, when the opening / closing member is fully opened, the impact of the opening / closing member due to the impact and the impact is caused by the speed change occurring at the moment and the speed when the cushioning member 106 is fully contracted (piston stop point S ′) suddenly becomes zero. Flaps and the like become large.

The two speed change points (the contact point S and the piston stop point S ') can be changed depending on the material, size, shape and the like of the buffer member 106. If the buffer member 106 is set delicately so as to reduce the speed change at the contact point S), the speed at the time when the buffer member 106 is fully contracted (piston stop point S ') suddenly becomes zero. Further, if the buffer member 106 is set so as not to suddenly become zero when the buffer member 106 contracts completely (piston stop point S), the speed change when the buffer member 106 contacts the buffer member 106 (contact point S) Are large, and it is difficult to avoid impact and flapping.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve or reduce such a conventional problem by reducing or reducing an impact generated when the piston comes into contact with a stopper via a buffer member when the piston is operated. It is to provide a gas spring characterized by the following.

[0007]

According to the present invention, a gas spring has a piston reciprocating in a cylinder, and a stopper for defining an operating range of the piston is provided in the cylinder. And a gas flow passage communicating with the chambers on both sides of the piston is provided in the piston, and an orifice plate for narrowing an opening of the gas flow passage of the piston by the stopper is provided adjacent to the piston.

[0008]

As described above, in the gas spring according to the present invention, the opening of the gas flow passage provided in the piston is narrowed by the orifice plate. Thus, the change in the speed up to the condition (1) can be smoothly reduced, whereby the impact before the stopper comes into contact with the stopper can be reduced.

In the gas spring according to the present invention, a cushioning member made of an elastic body such as rubber, a coil spring, a disc spring or the like is fixed to the stopper or slidable with respect to the piston rod between the stopper and the orifice plate. It is characterized by being provided.

Further, the gas spring according to the present invention is characterized in that the orifice plate is constituted by one orifice plate at least part of the outer peripheral side of which is warped toward the stopper.

Further, the gas spring of the present invention is characterized in that the orifice plate is constituted by a plate slidable in the axial direction, and an elastic member is provided between the plate and the piston.

Further, the gas spring according to the present invention is characterized in that an annular projection is provided on the end face of the piston.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments with reference to the accompanying drawings.

FIGS. 1 to 5 show first and second embodiments of the gas spring of the present invention.

(Embodiment 1) As shown in FIGS. 1 to 3, in the first embodiment of the gas spring of the present invention,
The gas spring 1 includes a cylinder 2 having one end pivotally supported by a fixed member (not shown) via an appropriate mounting member 8,
A piston 3 reciprocating in the cylinder 2, a piston rod 4 provided with the piston 3 at one end and the other end pivotally supported by a movable member (not shown), and a dish-shaped plate provided adjacent to the piston 3 An orifice plate 5, a buffer member 6 mounted on the piston rod 4, and a stopper 7 fixed in the cylinder 2 so as to regulate the movement of the piston 3.

In such a gas spring 1 of the present invention, the cylinder 2 has a substantially cylindrical shape, one end of which is pivotally supported by a fixed side member by an appropriate mounting member 8 and the other end of which is an oil seal 10 and a guide member 9. Thus, the piston rod 4 is slidably supported.

The piston 3 is attached to one end of a piston rod 4 and a seal ring 11 is mounted in an annular groove 12 on the outer peripheral surface of the piston so as to be in contact with the inner peripheral surface of the cylinder 2. The annular groove 12 of the piston 3 has a width greater than the width of the seal ring 11 and a depth greater than the thickness of the seal ring 11, so that the seal ring 11 is axially and diametrically inserted into the annular groove 12. Mounted with sufficient clearance. Further, a gas flow passage 13 extending in the axial direction and communicating with the annular groove 12 is provided so as to open to the piston end surface in the diametric direction on the piston rod 4 side with respect to the annular groove 12, and the chambers on both sides of the piston 3 are provided. Gas passage 1 penetrating the piston 3 in the axial direction so as to communicate
4 are provided. At least one, and preferably a plurality, of these gas flow passages 13 and 14 are provided in the piston 3, respectively, and the number and position thereof are determined as needed.

The orifice plate 5 is substantially disk-shaped, preferably at least part of the outer peripheral side is warped to the stopper side and is dish-shaped, and the pistons of the gas flow passages 13 and 14 are formed. The piston 3 is provided adjacent to the rod-side end face so as to open and close or narrow the opening on the rod 4 side. Further, the stopper 7 is fixed to the cylinder 2 by caulking or the like.

In the gas spring 1 of the present invention configured as described above, when the piston 3 operates to extend and fully extend as shown in FIG. 1, first, as shown in FIG. Before contacting the buffer member 6, the gas oil flows through the gap between the cylinder 2 and the piston 3, and seals the seal ring 11 in the annular groove 12.
2 presses against the wall surface on the side of the stopper 7 to shut off the space between the cylinder 2 and the piston 3, so that the gas oil
3, the gas flows through the outer peripheral portion of the orifice plate 5 to the gap between the cylinder 2 and the buffer member 6, and further flows into the gas flow passage 14.

Next, when the piston 3 extends most and comes into contact with the cushioning member 6, as shown in FIG. 3, the gap between the cylinder 2 and the piston 3 is blocked by the seal ring 11, and the gas oil The gas oil that has not flowed into the passage 13 flows out through the gas flow passage 14 so that the cushioning member 6 is sufficiently compressed as shown in FIG. The plate 5 is completely pressed and closely adhered between the piston 3 and the stopper 7 via the buffer member 6, and closes the gas flow passages 13 and 14.

Here, the cushioning member may not be provided. If a rubber cushioning member fixed to the stopper is provided, the gas flow passage should be narrowed without the orifice plate. The orifice plate serves to prevent the rubber cushioning member from being caught in the gas flow passage by pressure.

(Embodiment 2) FIGS. 4 and 5 show a gas spring 1a according to a second embodiment of the present invention. As shown, the gas spring 1a is different from the first embodiment. Similarly, a cylinder 2a whose one end is pivotally supported by the fixed member.
A piston 3a reciprocating in the cylinder 2a, a piston rod 4a provided with the piston 3a at one end and the other end pivotally supported by the movable member, and an orifice plate 5a provided adjacent to the piston 3a; Piston rod 4a
And a stopper 7a fixed in the cylinder 2a to regulate the movement of the piston 3a.

The gas spring 1 according to the present invention as described above.
5A, the cylinder 2a has a substantially cylindrical shape, one end of which is pivotally supported by a fixed member, and the other end of which is slidably supported by a suitable guide member. The piston 3a is provided at one end of the piston rod 4a, and a seal ring 11a is mounted in an annular groove 12a on the outer peripheral surface of the piston so as to be in contact with the inner peripheral surface of the cylinder 2a. The annular groove 12a of the piston 3a has a width greater than the width of the seal ring 11a and a depth greater than the thickness of the seal ring 11a.
a is mounted in the annular groove 12a with a sufficient gap in the axial direction and the diametrical direction.

Further, a gas flow passage 13a is provided in the annular groove 12a so as to extend in the axial direction so as to open at a diametrical end surface of the piston 3a on the piston rod 4a side and communicate with the annular groove 12a. , Piston 3a
A gas flow passage 14a penetrating the piston 3a in the axial direction is provided so as to communicate the chambers on both sides of the gas flow passage. A plurality of these gas flow passages 13a, 14a are provided in the piston 3a, respectively, and the number and position thereof are determined as needed.

The orifice plate 5a is provided adjacent to the rod-side end face of the piston 3a so as to reduce the amount of gas flowing out of the gas flow passages 13a and 14a from the piston rod 4a side. This orifice plate 5a
An annular projection 15a is provided on the end face of the piston 3a.
Are provided, and a spring 16a is provided in a recess formed inside by the projection 15a.
As the spring 16a, a coil spring or the like can be suitably used as shown in FIG. 6, and at least one appropriate notch 17a is provided around the spring 16a on the orifice plate 5a side. Is formed to allow outflow.

In the gas spring 1 according to the second embodiment of the present invention, when the piston 3a operates to extend and fully extend, the piston 3a comes into contact with the cushioning member 6a and the stopper 7a. Before the gas flows through the gap between the cylinder 2a and the piston 3a,
In the annular groove 12a, the seal ring 11a is
a, the gas flows through the gas flow passage 13a, and the notch 1 of the spring 16a.
The gas flows through the outer peripheral portion of the orifice plate 5a to the gap between the cylinder 2a and the cushioning member 6a, thereby damping the movement of the piston 3a.

Next, when the piston 3a extends most and comes into contact with the cushioning member 6a, as shown in FIG.
The gap between the cylinder 2a and the piston 3a is blocked by the seal ring 11a, and the remaining gas flows out through the gas flow passage 14a, and the cushioning member 6a is sufficiently compressed as shown in FIG. Stopped and buffered, the orifice plate 5a is completely
The gas flow passages 13a and 14a are closed by being pressed between and the stopper 7a via the buffer member 6a to be in close contact with each other.

[0028]

According to the gas spring of the present invention, the piston has a piston which reciprocates in the cylinder and a stopper is provided in the cylinder so that the piston does not move more than a predetermined amount. The opening of the gas flow passage provided in the piston is throttled by the orifice plate so as to communicate the chambers on both sides of the piston, so that the speed changes until the piston comes into contact with the stopper and the speed becomes zero. Can be smoothly reduced, thereby reducing the impact before the stopper comes into contact with the stopper.

Further, as described in claim 2, between the stopper and the orifice plate, rubber, a coil spring,
Since a buffer member made of an elastic body such as a disc spring is fixed to the stopper or slidably provided on the piston rod, in addition to the restriction by the orifice plate, rubber,
Since the deflection of the cushioning member made of an elastic body such as a coil spring or a disc spring is also absorbed and absorbed, the speed change can be further smoothed.

Further, since the orifice plate is constituted by one orifice plate at least part of the outer peripheral side of which is warped toward the stopper, the orifice plate can be constituted by one member, and the cost is reduced. Can be minimized.

Further, the orifice plate is constituted by a plate slidable in the axial direction, and an elastic member is provided between the plate and the piston. A portion to which a load is applied when contacted can be made of a material having high strength, and a portion to be elastically deformed can be made of a material and a shape which is easily elastically deformed, whereby durability can be improved.

Further, since the annular projection is provided on the end face of the piston as described in claim 5, the positioning of the elastic member can be facilitated.

[Brief description of the drawings]

FIG. 1 is an overall schematic sectional view of a first embodiment of a gas spring according to the present invention.

FIG. 2 is an enlarged partial sectional view of a piston portion of the gas spring of FIG.

FIG. 3 is a similar enlarged partial cross-sectional view of the gas spring of FIG. 2 when a piston portion contacts a cushioning member.

FIG. 4 is a similar enlarged partial sectional view of a piston portion of a gas spring according to a second embodiment of the present invention.

FIG. 5 is a similar enlarged partial cross-sectional view of the gas spring shown in FIG. 4 when a piston portion contacts a cushioning member.

FIG. 6 is a similar enlarged partial cross-sectional view of a piston portion in another embodiment of the gas spring of the present invention.

FIG. 7 is a diagram showing the elongation speed characteristics of the present invention and a conventional gas spring.

FIG. 8 is a schematic sectional view of an entire conventional gas spring.

[Explanation of symbols]

 Reference Signs List 1 gas spring 1a gas spring 2 cylinder 2a cylinder 3 piston 3a piston 4 piston rod 4a piston rod 5 orifice plate 5a orifice plate 6 buffer member 6a buffer member 7 stopper 7a stopper 8 fixing member 8a fixing member 9 guide member 10 oil seal 11 seal Ring 11a Seal ring 12 Annular groove 12a Annular groove 13 Gas flow passage 13a Gas flow passage 14 Gas flow passage 14a Gas flow passage 15 Projection 15a Projection 16 Spring 16a Spring 17 Notch 17a Notch

Claims (5)

[Claims] A piston that reciprocates in the cylinder, a stopper for defining an operating range of the piston is provided in the cylinder, and a gas flow passage communicating with chambers on both sides of the piston is provided in the piston. A gas spring, wherein an orifice plate for narrowing an opening of the gas flow passage is provided adjacent to the piston. 2. A cushioning member comprising an elastic body such as rubber, a coil spring, a disc spring, or the like is provided between the stopper and the orifice plate so as to be fixed to the stopper or slidable with respect to the piston rod. The gas spring according to claim 1, wherein 3. The gas spring according to claim 1, wherein the orifice plate is constituted by a single orifice plate having at least a portion on the outer peripheral side warped toward the stopper. 4. The gas according to claim 1, wherein the orifice plate comprises a plate slidable in the axial direction, and an elastic member is provided between the plate and the piston. spring. 5. The gas spring according to claim 1, wherein an annular projection is provided on the end face of the piston.