A piston valve type accumulator

Abstract

The present invention discloses a piston valve type accumulator, comprising: a cylinder barrel; a piston valve, the piston valve being suspended in the cylinder barrel; wherein the cylinder barrel is partitioned by the piston valve into an upper chamber for accommodating high-pressure gas and a lower chamber for accommodating high-pressure oil; an inflation port connected to a high-pressure gas pipe and a high-pressure oil port connected to a high-pressure oil pipe are provided at the bottom of the lower chamber. This piston valve type accumulator does not use a sealing ring, effectively overcoming defects such as short service life, piston sinking, gas entering the pipeline, easy system failures, and great maintenance difficulty caused by the damage of the sealing ring.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulics, and particularly to a piston valve type accumulator. Background Art

[0002] An accumulator is an energy storage device in a hydraulic system, and its function is to store the excess energy in the system at an appropriate time and release the stored energy when the system needs it and supply it back to the system. The piston type accumulator is a commonly used form of accumulator in the prior art. As Figure 1-2 shown, the cylinder barrel 110 is separated by a piston 120 located therein into an upper chamber 130 for accommodating high-pressure gas and a lower chamber 140 for accommodating high-pressure oil. Among them, an inflation port 111 connected to a high-pressure gas pipe 150 is provided at the top of the upper chamber 130, and the high-pressure gas in the upper chamber 130 is supplemented by adjusting an inflation valve 151 provided on the high-pressure gas pipe 150; a high-pressure oil port 112 connected to a high-pressure oil pipe 160 is provided at the bottom of the lower chamber 140, and the high-pressure oil in the lower chamber 140 is supplemented and released by adjusting a stop valve 161 provided on the high-pressure oil pipe 160; the piston 120 completely blocks the high-pressure gas in the upper chamber 130 from the high-pressure oil in the lower chamber 140 through a sealing ring 121 in close contact with the inner wall of the cylinder barrel 110. When in Figure 1 the first state shown, the piston 120 moves upward, and the excess energy in the system is converted into the compression energy of the high-pressure gas and stored; when in Figure 2 the second state shown, the piston 120 moves downward, and the compression energy of the high-pressure gas is converted into hydraulic energy and released into the system. Based on the above structure, the existing piston type accumulator 100 has the following defects:

[0003] 1. The sealing ring 121 rubs against the inner wall of the cylinder barrel 110 frequently for a long time, and is easy to be damaged, causing the piston to sink to the bottom, resulting in a short overall service life of the accumulator 100;

[0004] 2. After the sealing ring 121 is damaged, the compressed high-pressure gas is easy to enter the lower chamber 140 and enter the system through the high-pressure oil pipe 160 as the piston 120 moves downward, causing system failures;

[0005] 3. The sealing ring 121 is located inside the cylinder barrel 110. On the one hand, it is not conducive for the staff to detect its damaged state in time, and on the other hand, even if its damage is found, it is not easy to replace, resulting in great maintenance difficulty;

[0006] 4. Since the sealing ring 121 is in close contact with the cylinder barrel 110, to move the piston 120, the friction force between the sealing ring and the inner wall of the cylinder barrel must be overcome first, making the response speed of the accumulator 110 slow.

[0007] Therefore, how to reduce production and maintenance costs while extending the service life and accelerating the reaction speed has become a technical problem to be solved urgently in the field of accumulators. Summary of the Invention

[0008] To solve the existing technical problems, the present invention proposes a piston valve type accumulator with an extended service life and an accelerated reaction speed.

[0009] According to the present invention, there is provided a piston valve type accumulator, comprising: a cylinder barrel and a piston valve suspended in the cylinder barrel, wherein

[0010] The cylinder barrel is divided by the piston valve into an upper chamber for containing high-pressure gas and a lower chamber for containing high-pressure oil;

[0011] An air inlet for connecting a high-pressure gas pipe and a high-pressure oil port for connecting a high-pressure oil pipe are provided at the bottom of the lower chamber.

[0012] According to an embodiment of the present invention, the piston valve comprises a piston body, and the piston body is separated from the inner wall of the cylinder barrel to form an annular gap.

[0013] According to an embodiment of the present invention, the piston body comprises a bottom and a side wall extending upward from the outer edge of the bottom, and the bottom and the side wall define a cavity facing the upper chamber.

[0014] According to an embodiment of the present invention, a gasket is provided on the side wall of the piston body, and the gasket forms a protrusion facing the inner wall of the cylinder barrel on the outer surface of the side wall of the piston body.

[0015] According to an embodiment of the present invention, the piston valve comprises a ball valve, the ball valve is essentially located above the high-pressure oil port and is connected to the bottom of the piston body through a connecting member, and a sealing state is formed when the ball valve contacts the high-pressure oil port.

[0016] According to an embodiment of the present invention, the ball valve is flexibly connected to the bottom of the piston body through a connecting member.

[0017] According to an embodiment of the present invention, the piston valve type accumulator comprises a sensor for detecting the oil pressure of the high-pressure oil and a display device communicatively connected to the sensor, and the display device displays the liquid level height of the high-pressure oil in the piston valve type accumulator in response to a pressure signal from the sensor.

[0018] According to an embodiment of the present invention, the piston valve type accumulator comprises an alarm device communicatively connected to the sensor, and the alarm device issues an alarm in response to the oil pressure being less than the minimum oil pressure value exceeding a predetermined threshold.

[0019] According to an embodiment of the present invention, a detection port for connecting a detection pipeline is provided at the bottom of the cylinder barrel, and the sensor is provided on the detection pipeline.

[0020] According to an embodiment of the present invention, a high-pressure gas port is provided at the top of the cylinder barrel, and the high-pressure gas port is connected to a high-pressure gas cylinder through a connecting pipe.

[0021] Due to the above technical solutions, the present invention has the following advantages compared with the prior art:

[0022] 1. The piston valve type accumulator according to the present invention does not use a sealing ring, effectively overcoming defects such as short service life, easy system failure, and difficult maintenance caused by sealing ring damage;

[0023] 2. The piston valve type accumulator according to the present invention is light in weight and simple in structure, with low precision requirements for its components, effectively reducing production costs;

[0024] 3. The high-pressure gas is sealed in the completely enclosed upper chamber by the high-pressure oil, fundamentally eliminating the possibility of high-pressure gas leakage from the inflation port;

[0025] 4. The piston valve floats in the cylinder barrel relying on the buoyancy of the high-pressure oil and can move quickly in response to the pressure difference between the high-pressure gas and the high-pressure oil at any time;

[0026] 5. The piston valve can have a thin-walled structure with a light weight, which not only saves materials and space but also further speeds up the response rate of the piston valve;

[0027] 6. The piston valve type accumulator according to the present invention that does not use a sealing ring includes a sensor and a display device located outside the cylinder barrel, which helps the staff monitor the liquid level height and is convenient for maintenance and replacement;

[0028] 7. The piston valve type accumulator according to the present invention that does not use a sealing ring includes an alarm device, which can promptly inform the staff of the external leakage of high-pressure oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram showing the accumulator of the prior art in the first state;

[0030] Figure 2 A schematic diagram showing the accumulator of the prior art in the second state;

[0031] Figure 3 A schematic diagram showing an embodiment of the accumulator according to the present invention in the first state;

[0032] Figure 4 A schematic diagram showing an embodiment of the accumulator according to the present invention in the second state;

[0033] Figure 5 A schematic diagram showing another embodiment according to the present invention.

[0034] In the figure,

[0035] 100 Accumulator of the prior art, 110 cylinder barrel, 111 gas charging port, 112 high-pressure oil port, 120 piston, 121 sealing ring, 130 upper chamber, 140 lower chamber, 150 high-pressure gas pipe, 151 gas charging valve, 160 high-pressure oil pipe, 161 stop valve, 200 accumulator according to the present invention, 210 cylinder barrel, 211 gas charging port, 212 high-pressure oil port, 213 detection port, 214 high-pressure gas port, 220 piston valve, 221 piston body, 222 washer, 223 ball valve, 224 connecting component, 225 circumferential seam, 230 upper chamber, 240 lower chamber, 250 high-pressure gas pipe, 251 gas charging valve, 260 high-pressure oil pipe, 261 stop valve, 270 sensor, 280 detection pipeline, 281 detection valve, 290 connecting pipeline, 291 high-pressure gas cylinder. Detailed implementation manners

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] As Figure 2-3 shown, an embodiment 200 of a piston valve type accumulator according to the present invention generally includes a cylinder barrel 210 and a piston valve 220 suspended in the cylinder barrel 210. Specifically, the space inside the cylinder barrel 210 is separated into an upper chamber 230 and a lower chamber 240 by the piston valve 220. Among them, the upper chamber 230 is used to accommodate high-pressure gas with a smaller mass, while the lower chamber 240 is used to accommodate high-pressure oil with a larger mass. The piston valve 220 floats in the cylinder barrel 210 relying on the buoyancy of the high-pressure oil and moves up and down with the changes of air pressure and oil pressure. At the bottom of the lower chamber 240, there are provided a gas charging port 211 connected to the high-pressure gas pipe 250 and a high-pressure oil port 212 connected to the high-pressure oil pipe 260. A gas charging valve 250 is provided on the high-pressure gas pipe 250. Opening the gas charging valve 250 can charge the inside of the cylinder barrel 210, and the high-pressure gas automatically rises to the upper chamber 230 at the upper part of the cylinder barrel 210 due to its smaller mass. A stop valve 261 is provided on the high-pressure oil pipe 260. Opening the stop valve 261 realizes the replenishment and release of high-pressure oil, and the high-pressure oil deposits in the lower chamber 240 at the lower part of the cylinder barrel 210 due to its larger mass. When in Figure 3 the first state shown, the excess energy in the system increases the high-pressure oil pressure, pushing the piston valve 220 upward, and then converting the hydraulic energy into the compression energy of high-pressure gas for storage; when in Figure 4In the second state shown, the high-pressure gas pushes the piston valve 220 downward, and the compression energy of the high-pressure gas is converted into hydraulic energy and released into the system. When the piston valve 220 descends to contact the bottom of the cylinder barrel 210, it also seals the high-pressure oil port 212 at the bottom, so that a small amount of high-pressure oil remaining inside the cylinder barrel 210 no longer flows out, and the high-pressure gas sealed by the remaining high-pressure oil in the cylinder barrel 210 cannot flow out either. Based on the above structure, on the one hand, since the piston valve 220 floats in the cylinder barrel 210 without contacting the inner wall of the cylinder barrel, the piston valve 220 can quickly respond to the pressure difference between the high-pressure gas and the high-pressure oil and move; on the other hand, the inflation port 211 is arranged at the bottom of the lower chamber 240, and the high-pressure oil seals the high-pressure gas in the upper part, so that the upper chamber 230 containing the high-pressure gas forms a completely enclosed space as a whole, fundamentally eliminating the possibility of the high-pressure gas leaking from the inflation port. Further, compared with the piston accumulator 100, the piston valve type accumulator 200 completely gets rid of the use of the sealing ring 121, thus overcoming the defects such as short service life, easy system failure and difficult maintenance caused by the damage of the sealing ring 121.

[0038] In an embodiment of the present invention, the piston valve 220 may include a piston body 221, and the piston body 221 is separated from the inner wall of the cylinder barrel 210 to form an annular gap 225, so that the high-pressure gas and the high-pressure oil contact each other in the fine annular gap 225. The piston valve 220 floats in the cylinder barrel 210 in this way. Since the piston valve 220 can quickly move in response to the pressure difference between the high-pressure gas and the high-pressure oil at any time, compared with the piston 120 in the piston accumulator 100, it does not need to overcome the friction between the sealing ring 121 and the inner wall of the cylinder barrel 110, resulting in a significantly reduced pressure required for the piston valve 220. Therefore, the piston valve 220 of the present application can have a thin-wall structure with a relatively light mass. For example, the piston body 221 may include a bottom and a side wall extending upward from the outer edge of the bottom, so that the bottom and the side wall define a cavity facing the upper chamber 230. This cavity can be used as a part of the upper chamber 230 to accommodate high-pressure gas. With the above piston body 221, on the one hand, the thin-wall structure only needs to occupy a small space inside the cylinder barrel 210, and on the other hand, the reduced mass can make it more sensitive to pressure. In order to prevent high-pressure oil from entering the cavity during the movement of the piston valve 220, various measures can be taken. For example, the side wall of the piston body 221 can be designed to have a sufficient height to prevent the high-pressure oil from crossing the side wall and entering the cavity; or an inverted funnel-shaped cover can be arranged above the cavity, and the inclined surface of the funnel is used to block the hydraulic oil from entering the cavity while allowing the high-pressure gas to enter the cavity through the mouth of the funnel.

[0039] Preferably, a washer 222 can be provided on the side wall of the piston body 221, and the washer 222 can form a protrusion on the outer surface of the side wall of the piston body 221 facing the inner wall of the cylinder 210. Different from the sealing ring 121 in the piston accumulator 100, the washer 222 of the present invention is arranged not to contact the inner wall of the cylinder 210 or only have a slight contact with the inner wall of the cylinder 210, and its function is to prevent the piston body 221 from colliding with or wearing the cylinder 210, and the frictional force generated between the washer 222 and the cylinder 210 when the piston valve 220 moves up and down is almost negligible.

[0040] In another embodiment of the present invention, the piston valve 220 may further include a ball valve 223. The ball valve 223 is essentially located above the high-pressure oil port 212 and can be connected to the bottom of the piston body 221 through a connecting member 224. The function of the ball valve 223 is to make a sealing contact with the high-pressure oil port 212 when the piston valve 220 moves down to a specific height to prevent the high-pressure oil from flowing out continuously. In this embodiment, the ball valve 223 is designed to be spherical, and correspondingly, the upper part of the high-pressure oil port 212 is designed to be an inverted cone. Optionally, the upper part of the ball valve 223 and the high-pressure oil port 212 can also be designed into other shapes. The connection between the ball valve 223 and the bottom of the piston body 221 can be a rigid connection or a flexible connection. A rigid connection is beneficial for the piston valve 220 to be integrally formed with the same material, but has a higher requirement for the accuracy of the position of the ball valve 223, and it needs to be strictly located above the high-pressure oil port 212 to ensure the sealing performance; a flexible connection allows the position of the ball valve 223 to have a deviation within an appropriate range, and only needs to be generally located above the high-pressure oil port 212.

[0041] In a preferred embodiment of the present invention, the piston valve accumulator 200 may include a sensor 270 for detecting the oil pressure of the high-pressure oil and a display device (not shown in the figure) communicatively connected to the sensor 270. The display device can display the liquid level height of the high-pressure oil in the piston valve accumulator 200 in response to the oil pressure signal of the sensor 270. Specifically, when the piston valve 220 is stable:

[0042] P1*V1 = P2*V2 (1)

[0043] V1 = L1*S1 (2)

[0044] V2 = L2*S2 (3)

[0045] Wherein,

[0046] P1 is the air pressure value of the high-pressure gas;

[0047] V1 is the volume of the upper chamber 230, that is, the volume of the high-pressure gas;

[0048] P2 is the oil pressure value of the high-pressure oil;

[0049] V2 is the volume of the lower chamber 240, that is, the volume of the high-pressure oil;

[0050] L1 is the distance from the inner surface of the top of the cylinder barrel 210 to the upper surface of the piston valve 220, that is, the height of the high-pressure gas;

[0051] S1 is the area of the upper surface of the piston valve 220;

[0052] L2 is the distance from the inner surface of the bottom of the cylinder barrel to the lower surface of the piston valve 220, that is, the liquid level height of the high-pressure oil;

[0053] S2 is the area of the lower surface of the piston valve 220.

[0054] Since the areas of the upper and lower surfaces of the piston valve 220 are equal, that is, S1 = S2, the above formula can be simplified to:

[0055] P1*L1 = P2*L2 (4)

[0056] When the gas is in an equilibrium state, the gas pressure and volume satisfy the gas state equation:

[0057] PV = nRT (5)

[0058] Among them,

[0059] n is the amount of substance of the gas. Since the upper chamber 230 is a completely enclosed chamber, the n of the high-pressure gas is a fixed value;

[0060] R is the thermodynamic constant. For a specified gas, the value of R is constant;

[0061] T is the thermodynamic temperature. In a normal temperature working environment, the temperature change is extremely small and can be ignored, that is, the thermodynamic temperature T can be regarded as a fixed value.

[0062] Substituting formula (5) into formulas (3) and (4) gives:

[0063]

[0064] For the specified piston valve type accumulator 200, the area S2 of the lower surface of the piston valve 220 is a fixed value. Thus,

[0065]

[0066] Among them, K is a fixed value. Substituting formula (7) into formula (4) gives:

[0067] K = P1*L1 (8)

[0068] When the piston valve accumulator 200 is in the second state, the air pressure value P1 is the original state charging pressure P1origin of the high-pressure gas, and the height L1 of the high-pressure gas is the total height L of the inner cavity of the piston valve accumulator 200 minus the minimum liquid level height L2min. Since the original state charging pressure P1origin, the total height L of the inner cavity, and the minimum liquid level height L2min are all known parameters designed at the factory of the piston valve accumulator 200, the staff can calculate the K value based on this.

[0069] Through the K value and the oil pressure value P2 represented by the oil pressure signal, the liquid level height L2min of the high-pressure oil in any state can be calculated and displayed on the display device. The staff can detect the instantaneous liquid level height L2 of the high-pressure oil at any time. When the liquid level height L2min is less than the minimum liquid level height L2min by more than a predetermined threshold value ΔL, it can be determined that the high-pressure oil leaks and corresponding remedial measures can be taken. Among them, the predetermined threshold value ΔL is a value greater than or equal to zero, which represents the maximum value that allows the instantaneous liquid level height L2 to be less than the minimum liquid level height L2min within a reasonable range under the reference of external factors such as temperature, impurities, and errors.

[0070] The oil pressure sensor 270 can be arranged on the detection pipeline 280 outside the cylinder barrel 210, and the detection pipeline 280 is communicated with the high-pressure oil through the detection port 213 arranged at the bottom of the cylinder barrel 210. Further, a detection valve 281 can also be arranged on the detection pipeline 280 to control the flow of the high-pressure oil in the detection pipeline 280. Since the sensor 270 is located outside the cylinder barrel 210, compared with the prior art in which a liquid level sensor is arranged in the cylinder barrel 210, it is more convenient for maintenance and replacement.

[0071] In a further preferred embodiment, the piston valve accumulator 200 may further include an alarm device (not shown in the figure) communicatively connected to the sensor 270. The alarm device can issue an alarm in response to the detected oil pressure by the sensor 270 being less than the minimum oil pressure value P2min - that is, the oil pressure value P2 when the piston valve accumulator 200 is in the second state - exceeding a predetermined threshold value ΔP, so as to inform the staff that the high-pressure oil may leak, so that they can take corresponding remedial measures in time. Among them, the predetermined threshold value ΔL is a value greater than or equal to zero, which represents the maximum value that allows the oil pressure value P2 to be less than the minimum oil pressure value P2min within a reasonable range under the reference of external factors such as temperature, impurities, and errors.

[0072] In another preferred embodiment of the present invention, as Figure 5As shown, a high-pressure gas port 214 can be provided at the top of the cylinder barrel 210, and the high-pressure gas port 214 is connected to a high-pressure gas cylinder 291 capable of storing high-pressure gas through a connecting pipe 290. Thus, the volume of the upper chamber 230 can be increased by connecting an external high-pressure gas cylinder 291, and further the energy storage capacity of the piston valve type accumulator 200 can be improved. Further, the energy storage capacity of the piston valve type accumulator 200 can be changed by connecting external high-pressure gas cylinders 291 with different volumes.

[0073] The above embodiments only illustrate the implementation manners of the present invention, and the description thereof is relatively specific and detailed. However, it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. A piston valve type accumulator, characterized in that, Comprising: A cylinder barrel (210); A piston valve (220), which is suspended within the cylinder barrel (210); wherein The cylinder barrel (210) is partitioned by the piston valve (220) into an upper chamber (230) for accommodating high-pressure gas and being completely enclosed, and a lower chamber (240) for accommodating high-pressure oil; The bottom of the lower chamber (240) is provided with an inflation port (211) connected to a high-pressure gas pipe (250) and a high-pressure oil port (212) connected to a high-pressure oil pipe (260), wherein the high-pressure oil within the lower chamber (240) forms a liquid seal between the high-pressure gas in the upper chamber (230) and the inflation port (211).

2. The piston valve type accumulator according to claim 1, wherein The piston valve (220) comprises a piston body (221), and the piston body (221) is separated from the inner wall of the cylinder barrel (210) to form an annular gap (225).

3. The piston valve type accumulator according to claim 2, characterized in that, The piston body (221) comprises a bottom and a side wall extending upward from the outer edge of the bottom, and the bottom and the side wall define a cavity facing the upper chamber (230).

4. The piston valve type accumulator according to claim 3, characterized in that, A gasket (222) is provided on the side wall of the piston body (221), and the gasket (222) forms a protrusion on the outer surface of the side wall of the piston body (221) facing the inner wall of the cylinder barrel (210), and the gasket is arranged not to contact the inner wall of the cylinder barrel.

5. The piston valve type accumulator according to claim 3 or 4, characterized in that, The piston valve (220) comprises a ball valve (223), the ball valve (223) is essentially located above the high-pressure oil port (212) and is connected to the bottom of the piston body (221) through a connecting member (224), and a sealed state is formed when the ball valve (223) contacts the high-pressure oil port (212).

6. The piston valve type accumulator according to claim 5, characterized in that, The ball valve (223) is flexibly connected to the bottom of the piston body (221) through the connecting member (224).

7. The piston valve type accumulator according to claim 1, characterized in that, The piston valve type accumulator comprises a sensor (270) for detecting the oil pressure of the high-pressure oil and a display device communicatively connected to the sensor (270), and the display device displays the liquid level height of the high-pressure oil within the piston valve type accumulator in response to a pressure signal from the sensor (270).

8. The piston valve type accumulator according to claim 7, characterized in that, The piston valve type accumulator comprises an alarm device communicatively connected to the sensor (270), and the alarm device issues an alarm in response to the oil pressure being less than the minimum oil pressure value exceeding a predetermined threshold.

9. The piston valve type accumulator according to claim 7, characterized in that, The bottom of the cylinder barrel (210) is provided with a detection port (213) connected to a detection pipeline (280), and the sensor (270) is arranged on the detection pipeline (280).

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