Telescopic controllable double-tube gas spring

Abstract

Disclosed in the present invention is a telescopic controllable double-tube gas spring, comprising: an outer steel tube; an inner steel tube, which is slidably arranged in the outer steel tube by means of a piston; a hollow piston rod, a rear end of which extends into the inner steel tube from a front end of the outer steel tube; and a one-way throttle valve, a front end of which is connected to the hollow piston rod, wherein a control rod is slidably provided in the hollow piston rod; a valve needle is provided in the one-way throttle valve; the control rod cooperates with the valve needle to control the opening and closing of the one-way throttle valve; and the one-way throttle valve is in a sealed and sliding fit with an inner wall of the inner steel tube. By means of the present solution, slow extension and slow compression of the gas spring are realized, and easy downward compression thereof can also be realized, such that there is no jamming, shaking or noise, and a locking force value is great.

Description

A telescopic and controllable double-tube gas spring Technical Field

[0001] The present invention relates to the technical field of gas springs, and in particular to a telescopically controllable double-tube gas spring. Background Art

[0002] A gas spring is an industrial accessory that can provide support, cushioning, braking, height adjustment, and angle adjustment. It consists of a pressure cylinder, piston rod, piston, sealing guide sleeve, filler (inert gas or oil-gas mixture), in-cylinder and out-cylinder control elements (referring to controllable gas springs), and joints. The principle is to fill a sealed pressure cylinder with inert gas or oil-gas mixture, raising the pressure inside the chamber to several or even dozens of times higher than atmospheric pressure. The piston rod's movement is achieved by utilizing the pressure difference created by the smaller cross-sectional area of ​​the piston rod than the piston.

[0003] The existing gas springs that can be adjusted for extension and retraction have the problems of jamming and shaking during the extension and retraction process. The internal parts are prone to collision during rapid extension, emitting high-decibel noise. At the same time, there is a problem of low dead (locking) force value in the locked state and heavy downward pressure. The existing gas springs cannot achieve easy downward pressure when they can achieve slow extension and retraction, and cannot achieve slow extension and retraction when they can achieve easy downward pressure.

[0004] For example, the Chinese patent publication number CN212360610U, published on January 15, 2021, is named "A light-start double-tube controllable spring", which includes an outer steel tube, which is a hollow structure axially penetrated from the front and rear. The rear end opening of the outer steel tube is sealed with a first rear plug, and the front end opening of the outer steel tube is contracted inward to form a blocking surface; it also includes a hollow piston rod axially penetrated from the front and rear, and the rear end of the hollow piston rod is slid from the front end of the outer steel tube into the interior of the outer steel tube, and a guide sleeve for axial support and a bowl-shaped pad for sealing are respectively installed at the internal front end position of the outer steel tube.

[0005] The disadvantages of the existing patent are that the existing gas spring is prone to jamming, shaking and noise during rapid extension, and there are also problems such as low dead force value and heavy downforce in the locked state.

[0006] Summary of the Invention

[0007] The purpose of the present invention is to solve the problems of easy jamming, jitter and noise generated during the rapid extension of existing gas springs, as well as the problems of low dead force value and heavy downward pressure in the locked state. A double-tube gas spring with controllable extension and retraction is provided, so that the gas spring can be easily pressed down when it is slowly extended and retracted, without jamming, jitter and noise, and with a large dead force value.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A telescopic and controllable double-tube gas spring comprises: an outer steel tube; an inner steel tube, the inner steel tube being slidably arranged inside the outer steel tube by a piston; a hollow piston rod, the rear end of the hollow piston rod extending from the front end of the outer steel tube into the inner steel tube; a one-way throttle valve, the front end of the one-way throttle valve being connected to the hollow piston rod, a control rod being slidably provided inside the hollow piston rod, a valve needle being provided inside the one-way throttle valve, the control rod and the valve needle cooperating to control the opening and closing of the one-way throttle valve, and the one-way throttle valve being sealingly and slidingly fitted with the inner wall of the inner steel tube. The double-tube gas spring with controllable expansion and contraction described in this scheme has an air cavity between the outer steel tube and the inner steel tube, and an oil cavity between the one-way throttle valve and the inner steel tube. The control rod adjusts the valve needle to start and realize the expansion and contraction of the gas spring. When the external force on the control rod is removed, the valve needle generates a thrust to close the valve needle due to the difference in internal and external pressure and the external pressure is less than the internal pressure. At this time, the oil circuit is closed, the oil is difficult to compress, the internal pressure remains unchanged, the hollow piston rod can stay in any position, and the dead force value of the hollow piston rod is higher, the stability is better, and it can withstand larger external forces.

[0010] A double-tube structure design of inner and outer steel tubes is adopted. The outer steel tube is used for elastic buffering and the inner steel tube is used for stroke displacement, which greatly reduces the friction generated during the extension of the gas spring (the hollow piston rod is compressed after the valve needle is started); the gas spring extends slowly, achieving stroke extension without jamming or jitter, and slow extension avoids noise caused by collision of internal parts of the gas spring.

[0011] The rear end of the hollow piston rod is connected to a one-way throttle valve. During the extension of the gas spring, the one-way throttle valve acts as a throttle, making the gas spring extend slowly. During the depressing of the gas spring, the one-way throttle valve does not act as a throttle, making the gas spring depress easily. This allows the gas spring to extend slowly while also being able to be depress easily.

[0012] Preferably, the one-way throttle valve includes a throttle valve, which includes a valve body and a valve disc. The valve disc is sleeved on the valve body and slides axially along the central axis of the valve body. The valve body is provided with a flow channel, and the valve disc is provided with a notch at one end facing the flow channel, and the notch cooperates with the flow channel to form a throttle opening. When the valve needle is activated and compresses the hollow piston rod, the oil in the inner steel pipe flows from the throttle valve to the valve body piston, and the oil squeezes the valve disc toward the front end of the valve body. At this time, the throttle opening is open, and the one-way throttle valve does not have a throttling effect, making it easy to press the gas spring downward. When the valve needle is activated and extends the hollow piston rod, the oil in the inner steel pipe flows from the valve body piston to the throttle valve, and the oil squeezes the valve disc toward the rear end of the valve body. The valve disc cooperates with the flow channel to form a throttle opening, and the one-way throttle valve has a throttling effect, so that the gas spring extends slowly, achieving a stroke extension without blocking or shaking, and slowly extending to avoid collision of internal parts of the gas spring and generating noise.

[0013] Preferably, the valve disc comprises a non-nicked valve disc and a notched valve disc slidably mounted on the valve body, the notched valve disc being located at the rear end of the non-nicked valve disc, and the notch being located on the notched valve disc. The non-nicked valve disc, the notched valve disc, and the valve body are coaxially arranged, and the structural design of the non-nicked valve disc and the notched valve disc being coordinated facilitates valve disc processing.

[0014] Preferably, the valve body includes an axially penetrating valve body and a rivet, the rivet being axially riveted to the valve body, the rivet including a rivet tube and a rivet end provided at the front end of the rivet tube, the valve disc being sleeved on the rivet tube, and the rivet end limiting the valve disc on the rivet tube. The rivet serves to support the valve body and limit the valve disc. The flow channel is provided on the valve body, and there are multiple flow channels. The flow channels are distributed circumferentially according to the central axis of the valve body. An annular groove is provided at the front end of the valve body, and the annular groove is connected to the flow channel. The annular groove allows the oil to pass through the throttle hole evenly after passing through the flow channel, and the valve disc is evenly pressurized.

[0015] Preferably, the front end of the rivet tube body is open, the rear end of the rivet tube body is closed, the rivet tube body is coaxially arranged with the valve needle, and when the control rod is compressed, the rear end of the valve needle extends into the rivet tube body. The front end opening of the rivet tube body is used to avoid the expansion and contraction of the valve needle.

[0016] Preferably, the one-way throttle valve further includes a valve body piston, the valve body being connected to the rear end of the valve body piston, and the valve body piston sealingly and slidingly engaging with the inner wall of the inner steel tube. A sealing ring is provided between the valve body piston and the inner wall of the inner steel tube to provide a sealing effect. The one-way throttle valve slides within the inner steel tube in a sealing manner via the valve body piston.

[0017] Preferably, the rear end of the valve body piston is provided with a mounting groove, the front end of the valve body is fixedly mounted in the mounting groove, the interior of the inner steel pipe is connected to the valve body piston via a flow channel, and the valve body piston is fixedly clamped in the mounting groove.

[0018] Preferably, the rivet end abuts against the bottom of the mounting groove, and a notch is provided on the rivet end, the notch penetrating the interior of the valve body piston and the inner steel pipe. The notch prevents the rivet end from blocking the rear end of the valve body piston, and the valve body piston throttle valve passes through the notch.

[0019] Preferably, the one-way throttle valve comprises a valve body piston and a throttle valve, the throttle valve being disposed at the rear end of the valve body piston. The valve body piston is in sealing and sliding engagement with the inner wall of the inner steel tube. A sealing ring is provided between the valve body piston and the inner wall of the inner steel tube to provide a sealing effect. The one-way throttle valve slides within the inner steel tube through the valve body piston.

[0020] Preferably, a valve cavity is provided within the valve body piston, a flow hole is provided on the side wall of the valve body piston, an upper cavity is provided between the valve body piston and the front end of the inner steel tube, and a lower cavity is provided between the valve body piston and the throttle valve. The flow hole passes through the upper cavity and the valve cavity, and the valve cavity and the lower cavity are opened and closed by a valve needle. The lower cavity is connected to the interior of the inner steel tube. When the valve needle is activated and compresses the hollow piston rod, the oil in the inner steel tube passes through the flow channel, the throttle port, the lower cavity, the valve cavity, the flow hole, and enters the upper cavity in sequence. When the valve needle is activated and extends the hollow piston rod, the oil in the upper cavity passes through the flow hole, the valve cavity, the lower cavity, the flow channel, and enters the oil cavity in sequence.

[0021] Preferably, a gasket is disposed within the lower cavity, through which the valve needle passes. The inner sidewall of the gasket, facing the throttle valve, has a conical surface that is narrower at the front and wider at the rear. The conical surface of the gasket cooperates with the valve needle to minimize cross-sectional changes in the oil as it passes through the lower cavity, thereby reducing oil turbulence.

[0022] Preferably, a sealing ring is provided between the valve needle and the inner wall of the piston valve body, and the gasket limits the sealing ring in the valve cavity. The gasket is used to limit the limiting ring in the valve cavity.

[0023] Therefore, the present invention has the following beneficial effects:

[0024] (1) The hollow piston rod can stay in any position. The hollow piston rod has a higher dead force value, better stability, and can withstand larger external forces;

[0025] (2) A double-tube structure design of inner and outer steel tubes is adopted. The outer steel tube is used for elastic buffering and the inner steel tube is used for stroke displacement, which greatly reduces the friction generated during the extension of the gas spring. The gas spring extends slowly, achieving stroke extension without obstruction or jitter, and slow extension avoids collision of internal parts of the gas spring and noise.

[0026] (3) The rear end of the hollow piston rod is connected to a one-way throttle valve. During the extension of the gas spring, the one-way throttle valve plays a throttling role, making the gas spring extend slowly; during the downward pressure of the gas spring, the one-way throttle valve does not play a throttling role, making the gas spring easy to press down; the gas spring can be extended slowly while also being easily pressed down. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a cross-sectional view of the present invention.

[0028] FIG2 is a cross-sectional view of the connection between the hollow piston rod and the one-way throttle valve in the present invention.

[0029] FIG3 is a partial enlarged view of point A in FIG1 .

[0030] FIG4 is a schematic diagram of a structure of a missing valve plate in the present invention.

[0031] FIG5 is a schematic structural diagram of the valve body piston in the present invention.

[0032] FIG6 is a schematic structural diagram of a rivet in the present invention.

[0033] FIG7 is a schematic structural diagram of the valve body of the present invention.

[0034] FIG8 is a schematic structural diagram of a gasket in the present invention.

[0035] As shown in the figure: outer steel tube 1, inner steel tube 2, piston 3, hollow piston rod 4, control rod 5, valve needle 6, valve body piston 7, mounting groove 7.1, flow hole 7.2, valve body 8, flow channel 8.1, valve body 8.2, rivet tube 8.3, rivet end 8.4, valve disc 9, notch 9.1, intact valve disc 9.2, notched valve disc 9.3, valve cavity 10, upper cavity 11, lower cavity 12, gasket 13, conical surface 13.1. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the technical solution embodiments of the present invention clearer, the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0037] Specific embodiment 1, a telescopic controllable double-tube gas spring as shown in Figures 1 to 8, includes: an outer steel tube 1; an inner steel tube 2, the inner steel tube 2 is slidably arranged in the outer steel tube 1 through a piston 3; a hollow piston rod 4, the rear end of the hollow piston rod 4 extends from the front end of the outer steel tube 1 into the inner steel tube 2; a one-way throttle valve, the front end of the one-way throttle valve is connected to the hollow piston rod 4, a control rod 5 is slidably provided in the hollow piston rod 4, a valve needle 6 is provided in the one-way throttle valve, the control rod 5 and the valve needle 6 cooperate to control the opening and closing of the one-way throttle valve, the one-way throttle valve is sealed and slidably cooperated with the inner wall of the inner steel tube 2, and the one-way throttle valve controls throttling when the hollow piston rod 4 is extended.

[0038] The above embodiment is a double-tube gas spring with controllable expansion and contraction, an air cavity is provided between the outer steel tube 1 and the inner steel tube 2, an oil cavity is provided between the one-way throttle valve and the inner steel tube 2, and the control rod 5 adjusts the valve needle 6 to start and realize the expansion and contraction of the gas spring; when the external force on the control rod 5 is removed, the valve needle 6 generates a thrust to close the valve needle 6 due to the difference in internal and external pressure and the external pressure is less than the internal pressure. At this time, the oil circuit is closed, the oil is difficult to compress, the internal pressure remains unchanged, the hollow piston rod 4 can stay at any position, and the dead force value of the hollow piston rod 4 is higher, the stability is better, and it can withstand larger external forces.

[0039] The invention solves the problems of jamming, shaking and noise easily generated during the rapid extension of the existing gas spring, and the problems of low dead force value and heavy downforce in the locked state.

[0040] A double-tube structure design of an inner steel tube 2 and an outer steel tube 1 is adopted. The outer steel tube 1 is used for elastic buffering and the inner steel tube 2 is used for stroke displacement, so that the friction generated during the extension of the gas spring (the hollow piston rod 4 is compressed after the valve needle 6 is started) is greatly reduced; the gas spring extends slowly, achieving stroke extension without jamming or shaking, and slow extension avoids collision of internal parts of the gas spring and noise.

[0041] The rear end of the hollow piston rod 4 is connected to a one-way throttle valve. During the extension of the gas spring, the one-way throttle valve acts as a throttle, making the gas spring extend slowly. During the depressing of the gas spring, the one-way throttle valve does not act as a throttle, making the gas spring depress easily. This allows the gas spring to extend slowly while also being easily depressible.

[0042] Specifically, as shown in Figures 1, 2, and 3, the one-way throttle valve includes a valve body piston 7 and a throttle valve. The throttle valve is disposed at the rear end of the valve body piston 7. The valve body piston 7 slides in a sealed manner against the inner wall of the inner steel tube 2. A sealing ring is provided between the valve body piston 7 and the inner wall of the inner steel tube 2 to provide a sealing effect. The one-way throttle valve slides in a sealed manner within the inner steel tube 2 via the valve body piston 7.

[0043] As shown in Figures 1, 2, 3 and 4, the throttle valve includes a valve body 8 and a valve disc 9. The valve body 8 is connected to the rear end of the valve body piston 7. The valve disc 9 is sleeved on the valve body 8 and slides axially along the central axis of the valve body 8. A flow channel 8.1 is provided on the valve body 8. A notch 9.1 is provided on the end of the valve disc 9 facing the flow channel 8.1. The notch 9.1 cooperates with the flow channel 8.1 to form a throttle port. The throttle port throttles in one direction. The flow channel 8.1 passes through the interior of the inner steel pipe 2 and the valve body piston 7. When the valve needle 6 is activated and compresses the hollow piston rod 4, the oil in the inner steel pipe 2 flows from the throttle valve to the valve body piston 7. The oil squeezes the valve disc 9 and moves toward the front end of the valve body 8. At this time, the throttle port is open, and the one-way throttle valve does not have a throttling effect, making it easy for the gas spring to be pressed down. After the valve needle 6 is started and the hollow piston rod 4 is extended, the oil in the inner steel tube 2 flows from the valve body piston 7 to the throttle valve, and the oil squeezes the valve plate 9 to move toward the rear end of the valve body 8. The valve plate 9 cooperates with the flow channel 8.1 to form a throttle port. At this time, the one-way throttle valve plays a throttling role, making the gas spring extend slowly, achieving stroke extension without obstruction or jitter, and slow extension to avoid collision of internal parts of the gas spring and noise.

[0044] Further optimization of valve disc 9, as shown in Figures 3 and 4, comprises a complete valve disc 9.2 and a notched valve disc 9.3, which are slidably mounted on valve body 8. The notched valve disc 9.3 is located at the rear end of the complete valve disc 9.2, and the notch 9.1 is located on the notched valve disc 9.3. The notched valve disc 9.3 and the complete valve disc 9.2 cooperate with the flow passage 8.1 of the valve body 8 to form a throttle. The complete valve disc 9.2, the notched valve disc 9.3, and the valve body 8 are coaxially arranged. The structural design of the complete valve disc 9.2 and the notched valve disc 9.3 makes the valve disc 9 easy to manufacture.

[0045] In this embodiment, the intact valve disc 9.2 and the defective valve disc 9.3 are an integrally formed structure, or the intact valve disc 9.2 and the defective valve disc 9.3 are manufactured separately and then connected as one; or the intact valve disc 9.2 and the defective valve disc 9.3 are manufactured separately, and the intact valve disc 9.2 and the defective valve disc 9.3 are each independently slidably sleeved on the valve body 8.

[0046] In this embodiment, the valve body 8 comprises an axially extending valve body 8.2 and a rivet. The rivet is axially riveted to the valve body 8.2. The rivet comprises a rivet tube 8.3 and a rivet head 8.4 disposed at the front end of the rivet tube 8.3. The valve disc 9 is sleeved onto the rivet tube 8.3, and the rivet head 8.4 retains the valve disc 9 in position on the rivet tube 8.3. The rear end of the valve piston 7 is provided with a mounting groove 7.1, and the front end of the valve piston 7 is fixedly mounted within the mounting groove 7.1. The interior of the inner steel tube 2 and the valve piston 7 are connected through the flow channel 8.1. The rivet head 8.4 abuts the bottom of the mounting groove 7.1 and has a notch extending through the interior of the valve piston 7 and the inner steel tube 2. The rivet supports the valve body 8.2 and limits the valve disc 9. There are multiple flow channels 8.1, which are arranged on the valve body. The flow channels 8.1 are distributed circumferentially according to the central axis of the valve body 8. An annular groove is provided at the front end of the valve body 8.2, which is connected to the flow channel 8.1. The annular groove allows the oil to pass through the flow channel 8.1 and evenly pass through the throttle hole. The valve plate 9 is evenly pressurized. The notch prevents the rivet end 8.4 from blocking the rear end of the valve body piston 7. The throttle valve of the valve body piston 7 is connected through the notch.

[0047] Furthermore, the front end of the rivet tube body is open and the rear end is closed. The rivet tube body 8.3 is coaxially arranged with the valve needle 6, with the front end opening of the rivet tube body facing the valve needle. When the control rod 5 is compressed, the rear end of the valve needle 6 extends into the rivet tube body through the front end opening of the rivet tube body.

[0048] In this embodiment, as shown in FIG3 , a valve chamber 10 is defined within the valve body piston 7. A flow hole 7.2 is defined on the sidewall of the valve body piston 7. An upper chamber 11 is defined between the valve body piston 7 and the front end of the inner steel tube 2. A lower chamber 12 is defined between the valve body piston 7 and the throttle valve. The flow hole 7.2 extends through the upper chamber 11 and the valve chamber 10. The valve chamber 10 and the lower chamber 12 are opened and closed by the valve needle 6. The lower chamber 12 communicates with the interior of the inner steel tube 2. When the valve needle 6 is activated and compresses the hollow piston rod 4, the oil in the inner steel tube 2 passes through the flow passage 8.1, the throttle port, the lower chamber 12, the valve chamber 10, the flow hole 7.2, and enters the upper chamber 11. When the valve needle 6 is activated and extends the hollow piston rod 4, the oil in the upper chamber 11 passes through the flow hole 7.2, the valve chamber 10, the lower chamber 12, the flow passage 8.1, and enters the oil chamber.

[0049] Furthermore, as shown in Figures 2, 3, and 8, a sealing ring is provided between the valve needle 6 and the inner wall of the valve body 8 of the piston 3. In this embodiment, there are two sealing rings, which are distributed along the axial direction of the valve needle. The flow hole is located between the two sealing rings.

[0050] A gasket 13 is provided in the lower cavity. In this embodiment, a limiting groove is provided at the bottom of the mounting groove 7.1, and the inner cavity of the limiting groove constitutes the lower cavity. The gasket 13 limits the sealing ring in the valve cavity 10. The valve needle 6 passes through the gasket 13. The inner side wall of the gasket 13 facing the throttle valve is a conical surface 13.1 that is smaller in front and larger in the back. The gasket 13 is used to limit the limiting ring in the valve cavity 10, and the gasket 13 is stuck in the limiting groove. The conical surface 13.1 on the gasket 13 cooperates with the valve needle 6, so that the cross-sectional change of the oil when passing through the lower cavity 12 is small, thereby reducing the turbulence of the oil.

[0051] The outer steel tube 1 is a hollow structure that extends axially from front to back. The rear end of the outer steel tube 1 is sealed with a first back plug. The front end opening of the outer steel tube 1 is contracted inward to form a blocking surface. A sealing guide assembly is provided at the front end of the inner steel tube 1 to axially support the hollow piston rod 4, forming an air cavity between the outer steel tube 1 and the inner steel tube 2. The inner steel tube 2 is a hollow structure that extends axially from front to back. The front end of the inner steel tube 2 is fixedly connected to the piston 3. The rear end of the inner steel tube 2 is sealed with a second back plug. The second back plug is equipped with a guide sleeve that slides with the inner wall of the outer steel tube 1. An oil cavity is formed between the one-way throttle valve and the inner steel tube 2.

[0052] The sealing guide assembly includes a guide sleeve, an oil seal and a spacer sleeve from front to back.

[0053] The operating principle of the present invention is: when the external force presses the control rod 5, the control rod 5 moves, thereby pushing the valve needle 6 to start, so that the upper cavity 11, the valve cavity 10, and the lower cavity 12 are connected, and then the external force continues to press the hollow piston rod 4. When the external force is greater than the supporting force of the hollow piston rod 4, the hollow piston rod 4 continues to press down. Since the hollow piston rod 4 squeezes the oil in the inner steel tube 2, the oil in the oil cavity is squeezed and enters the flow channel 8.1, the lower cavity 12, the valve cavity 10 and the flow hole 7.2 in turn to flow into the upper cavity 11. At the same time, due to the reaction force of friction, the hollow piston rod 4 drives the inner steel tube 2 to move into the outer steel tube 1. Since the piston 3 moves with the inner steel tube 2, the gas in the air cavity is compressed. At this time, the throttle port is opened and cannot throttle. Due to the flow effect, the gas spring is easily pressed down; when the external force is less than the supporting force of the hollow piston rod 4, the hollow piston rod 4 extends outward, so that the oil in the upper cavity 11 is squeezed into the valve cavity 10 and flows into the oil cavity through the throttle valve, and the hollow piston rod 4 extends out of the inner steel tube 2. At the same time, the gas pressure in the gas cavity pushes the piston 3 to move outward. At this time, the throttle valve plays a throttling role, so that the gas spring extends slowly; when the external force on the control rod 5 is removed, the valve needle 6 generates a thrust to close the valve needle 6 due to the difference in internal and external pressure and the external pressure is less than the internal pressure. The valve needle 6 separates the valve cavity 10 and the lower cavity 12. At this time, the oil circuit is closed, the oil is difficult to compress, the internal pressure remains unchanged, the hollow piston rod 4 can stay at any position, and the locking force of the piston rod 3 is higher and the stability is better.

[0054] The present invention has the following beneficial effects: the hollow piston rod 4 can stay at any position, the dead force value of the hollow piston rod 4 is high, the stability is good, and it can withstand large external forces; a double-tube structure design of an inner steel tube 2 and an outer steel tube 1 is adopted, the outer steel tube 1 is used for elastic buffering, and the inner steel tube 2 is used for stroke displacement, so that the friction generated during the extension of the gas spring is greatly reduced; the gas spring extends slowly, and the stroke extension is achieved without jamming or shaking, and the slow extension avoids the collision of internal parts of the gas spring to produce noise; the rear end of the hollow piston rod 4 is connected to a one-way throttle valve, and the one-way throttle valve plays a throttling role during the extension of the gas spring, so that the gas spring extends slowly; the one-way throttle valve does not play a throttling role during the downward pressure of the gas spring, so that the gas spring can be easily pressed down; the gas spring can be extended slowly while also achieving the performance of easy downward pressure.

[0055] The above-described specific embodiments are only preferred embodiments of the present invention and are not intended to limit the specific implementation scope of the present invention. All equivalent changes made to the shape and structure of the present invention should be included in the protection scope of the present invention.

Claims

1. A telescopic and controllable double-tube gas spring, characterized in that: include: Outer steel tube (1); An inner steel tube (2), the inner steel tube being slidably arranged in the outer steel tube via a piston (3); A hollow piston rod (4), the rear end of which extends from the front end of the outer steel tube into the inner steel tube; A one-way throttle valve, the front end of which is connected to a hollow piston rod, a control rod (5) is slidably provided inside the hollow piston rod, a valve needle (6) is provided inside the one-way throttle valve, the control rod and the valve needle cooperate to control the opening and closing of the one-way throttle valve, and the one-way throttle valve is sealingly slidably cooperated with the inner wall of the inner steel pipe.

2. The telescopic and controllable double-tube gas spring according to claim 1 is characterized in that: The one-way throttle valve comprises a throttle valve, which comprises a valve body (8) and a valve plate (9), wherein the valve plate is sleeved on the valve body, the valve plate slides axially along the central axis of the valve body, a flow channel (8.1) is provided on the valve body, and a notch (9.1) is provided at one end of the valve plate facing the flow channel, wherein the notch cooperates with the flow channel to form a throttle opening.

3. The telescopic and controllable double-tube gas spring according to claim 2 is characterized in that: The valve plate comprises a perfect valve plate (9.2) and a flawed valve plate (9.3) which are slidably sleeved on the valve body, the flawed valve plate is located at the rear end of the perfect valve plate, and the flaw is located on the flawed valve plate.

4. A telescopic and controllable double-tube gas spring according to claim 2 or 3, characterized in that: The valve body comprises an axially penetrating valve body main body (8.2) and a rivet, the rivet being axially riveted to the valve body main body, the rivet comprising a rivet tube body (8.3) and a rivet end head (8.4) arranged at the front end of the rivet tube body, the valve plate is sleeved on the rivet tube body, and the rivet end head limits the valve plate on the rivet tube body.

5. The telescopic and controllable double-tube gas spring according to claim 4 is characterized in that: The flow channel is arranged on the valve body, and an annular groove is arranged at the front end of the valve body, and the annular groove is connected with the flow channel.

6. The telescopic and controllable double-tube gas spring according to claim 4 is characterized in that: The front end of the rivet tube body is open, the rear end of the rivet tube body is closed, the rivet tube body is coaxially arranged with the valve needle, and when the control rod is compressed, the rear end of the valve needle extends into the rivet tube body.

7. The telescopic and controllable double-tube gas spring according to claim 4 is characterized in that: The one-way throttle valve also includes a valve body piston (7), the valve body is connected to the rear end of the valve body piston, and the valve body piston is in sealing and sliding cooperation with the inner wall of the inner steel pipe.

8. The telescopic and controllable double-tube gas spring according to claim 7 is characterized in that: The rear end of the valve body piston is provided with a mounting groove (7.1), the front end of the valve body is fixedly mounted in the mounting groove, and the interior of the inner steel pipe is connected to the valve body piston through a flow channel.

9. The telescopic and controllable double-tube gas spring according to claim 8, characterized in that: The rivet end is in contact with the bottom of the installation groove, and a notch is arranged on the rivet end, and the notch passes through the inside of the valve body piston and the inner steel pipe.

10. The telescopic and controllable double-tube gas spring according to claim 1, 2 or 3, characterized in that: The one-way throttle valve comprises a valve body piston (7) and a throttle valve, wherein the throttle valve is arranged at the rear end of the valve body piston, and the valve body piston is sealingly slidably matched with the inner wall of the inner steel pipe.

11. The telescopic and controllable double-tube gas spring according to claim 10, characterized in that: A valve cavity (10) is provided in the valve body piston, a flow hole (7.2) is provided on the side wall of the valve body piston, an upper cavity (11) is provided between the valve body piston and the front end of the inner steel pipe, a lower cavity (12) is provided between the valve body piston and the throttle valve, the flow hole passes through the upper cavity and the valve cavity, the valve cavity and the lower cavity are opened and closed by a valve needle, and the lower cavity is connected to the interior of the inner steel pipe.

12. The telescopic and controllable double-tube gas spring according to claim 11, characterized in that: A gasket (13) is arranged in the lower cavity, and the valve needle passes through the gasket. The inner side wall of the end of the gasket facing the throttle valve is a conical surface (13.1) that is smaller at the front and larger at the rear.

13. The telescopic and controllable double-tube gas spring according to claim 12, characterized in that: A sealing ring is arranged between the valve needle and the inner wall of the piston valve body, and the gasket limits the sealing ring in the valve cavity.

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