Synchronous oil cylinder

Abstract

The invention relates to the technical field of hydraulic cylinders, in particular to a synchronous oil cylinder which comprises a cylinder barrel, a cylinder cover is installed at the bottom end of the cylinder barrel, a first-stage piston cylinder barrel and a second-stage piston cylinder barrel are arranged in the cylinder barrel in a sliding mode, and a built-in displacement sensor extending into the second-stage piston cylinder barrel is fixed to the cylinder cover. The cross sectional area of the first-stage cavity and the cross sectional area of the second-stage cavity are set to be equal, it is guaranteed that oil can be transmitted between stages equivalently and stably, and therefore synchronous telescopic movement of all stages of cylinder barrels is achieved. The impact problems of pressure sudden change, speed jump, instant rushing-out of the second-stage piston and the like caused by stage change of a traditional multi-stage cylinder are fundamentally solved, and the action speed of the oil cylinder is remarkably increased. And through a built-in sensor, the structure is more compact, high-precision displacement signals can be fed back in real time, and precise adjustment on the action of the oil cylinder is achieved in cooperation with a control system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic cylinders, in particular to a synchronous oil cylinder. BACKGROUND

[0002] Multi-stage telescopic cylinders are widely used in various industries due to small installation space and long stroke. The current mainstream structure is step-by-step telescopic, which acts in size order, and the oil cylinder acts slowly. And under constant input flow, due to the different areas of each stage of the piston, the extension speed and pressure will change suddenly with the change of the stage, causing significant stage impact. Especially when the first stage piston moves to the limit, the second stage piston often bursts out violently due to the instantaneous increase of pressure, causing the hydraulic cylinder to vibrate violently and poor stability. This non-synchronous movement mode limits the high-speed operation capability of the system and makes it difficult to achieve smooth and precise displacement control.

[0003] Based on the above technical problems, the present application provides a synchronous oil cylinder. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a synchronous oil cylinder to solve the above technical problems.

[0005] The present application is realized by the following technical scheme: a synchronous oil cylinder, comprising a cylinder barrel, a cylinder cover is arranged at the bottom end of the cylinder barrel; a multi-stage piston cylinder and a displacement sensor are arranged inside the cylinder barrel, and a multi-stage linkage cavity is formed between the multi-stage piston cylinder and the displacement sensor; The multi-stage piston cylinder comprises a first stage piston cylinder arranged inside the cylinder barrel, and a second stage piston cylinder arranged inside the first stage piston cylinder; The displacement sensor is fixedly arranged on the cylinder cover, and the detection end of the displacement sensor extends into the interior of the second stage piston cylinder; The multi-stage linkage cavity comprises a first stage cavity formed between the cylinder barrel and the first stage piston cylinder, a second stage cavity formed between the first stage piston cylinder and the second stage piston cylinder, and a third stage cavity formed between the second stage piston cylinder and the displacement sensor; The multi-stage linkage cavity is separated into a rod cavity and a rodless cavity by the corresponding stage of the piston.

[0006] Further, a first oil port for driving the first stage cavity and the second stage cavity to extend synchronously is arranged on the side wall of the first stage piston cylinder, the first oil port communicates the rod cavity of the first stage cavity and the rodless cavity of the second stage cavity, and the first oil port is provided with a plurality of first oil ports which are uniformly distributed along the circumference of the first stage piston cylinder.

[0007] Further, a second oil port for driving the first stage cavity and the second stage cavity to retract synchronously is arranged on the second stage piston cylinder, and the second oil port communicates the third stage cavity and the rod cavity of the second stage cavity.

[0008] Further, a sealing device is arranged between the secondary piston cylinder and the displacement sensor, the sealing device comprising a partition cylinder, an end of the partition cylinder being fixedly connected to the piston part of the primary piston cylinder, and a channel one for hydraulic oil circulation being left between the partition cylinder and the secondary piston cylinder.

[0009] Further, the sealing device further comprises a sealing cylinder, the sealing cylinder being fixedly arranged on the cylinder cover and sealingly matched with the inner wall of the partition cylinder, and a channel two for hydraulic oil circulation being left between the sealing cylinder and the displacement sensor.

[0010] Further, a magnetic ring for detecting the displacement of the primary piston cylinder is arranged between the partition cylinder and the primary piston cylinder.

[0011] Further, an extension cylinder oil port is arranged on the cylinder cover, and the extension cylinder oil port is communicated with the primary cavity through the channel one.

[0012] Further, a retraction cylinder oil port is arranged on the cylinder cover, and the retraction cylinder oil port is communicated with the tertiary cavity through the channel two.

[0013] The beneficial effects of the present application are as follows: a synchronous oil cylinder, comprising a cylinder, a cylinder cover being arranged at the bottom end of the cylinder; a plurality of piston cylinders and a displacement sensor being arranged inside the cylinder, a plurality of linkage cavities being formed between the plurality of piston cylinders and the displacement sensor; the plurality of piston cylinders comprising a primary piston cylinder arranged inside the cylinder, and a secondary piston cylinder arranged inside the primary piston cylinder; the displacement sensor being fixedly arranged on the cylinder cover, and a detection end of the displacement sensor extending into the inside of the secondary piston cylinder; by arranging the cross sections of the primary cavity and the secondary cavity to be equal in area, and constructing the plurality of linkage cavity structures, the oil can be transferred between the stages in equal amounts and smoothly. This completely solves the problems of pressure sudden change and speed jump caused by the area difference of the pistons in the traditional step-by-step telescopic cylinder, ensures that the primary cylinder and the secondary cylinder always maintain the same pace during the extension and retraction process, and the running track is smooth. In the running process, the "instantaneous outburst" phenomenon and violent vibration of the secondary piston caused by sudden pressure increase are effectively avoided. This not only reduces the transient load of the hydraulic system and reduces the wear of the sealing parts and mechanical structure, but also enables the equipment to maintain high motion stability under high-speed working conditions, prolonging the service life. Installing the built-in displacement sensor inside the hydraulic cavity not only utilizes the internal space to make the structure more compact, but also can feedback the accurate displacement data of the secondary cylinder in the whole stroke in real time. Combined with the control system, closed-loop precise adjustment of the action of the oil cylinder can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 It is a schematic diagram of the overall structure of the synchronous oil cylinder; Fig. 2 It is a schematic diagram of the synchronous oil cylinder in cross section; Fig. 3This is a schematic diagram of the cylinder barrel in the extended state.

[0015] In the diagram: 1. Cylinder barrel; 11. Cylinder head; 12. Sealing head one; 13. Sealing head two; 2. First-stage piston cylinder barrel; 21. First-stage chamber; 22. First oil port; 3. Second-stage piston cylinder barrel; 31. Second-stage chamber; 32. Second oil port; 4. Divider; 41. Tertiary chamber; 5. Sealing cylinder; 6. Displacement sensor; 7. Cylinder retraction port; 8. Cylinder extension port. Detailed Implementation

[0016] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 like Figs. 1-3 As shown, this embodiment discloses a synchronous hydraulic cylinder, including a cylinder barrel 1, a cylinder cover 11 installed at the bottom end of the cylinder barrel 1, the cylinder cover 11 and the cylinder barrel 1 are fixedly connected by threads, a sealing head 12 is fixedly installed at the top end of the cylinder barrel 1, and a cylinder retraction port 7 and a cylinder extension port 8 are provided on the side wall of the cylinder cover 11.

[0019] A first-stage piston cylinder 2 is slidably installed inside cylinder 1. The outer diameter of the cylinder part of the first-stage piston cylinder 2 is smaller than the inner diameter of cylinder 1 and equal to the inner diameter of the sealing head 12. The outer diameter of the piston part of the first-stage piston cylinder 2 is equal to the inner diameter of cylinder 1. The chamber between the first-stage piston cylinder 2 and cylinder 1 forms a first-stage chamber 21, which is filled with hydraulic oil. The first-stage chamber 21 is divided into a rod chamber and a rodless chamber by the piston part of the first-stage piston cylinder 2. The cylinder extension port 8 is connected to the first-stage chamber 21 and is located in the rodless chamber at the bottom of the piston of the first-stage piston cylinder 2.

[0020] The second-stage piston cylinder 3 is slidably installed in the first-stage piston cylinder 2, the cylinder part of the second-stage piston cylinder 3 has an outer diameter smaller than the inner diameter of the cylinder part of the first-stage piston cylinder 2 and is matched with the sealing head 13 on the inner side of the piston part of the first-stage piston cylinder 2, the piston part of the second-stage piston cylinder 3 has an outer diameter equal to the inner diameter of the cylinder part of the first-stage piston cylinder 2, the cavity between the second-stage piston cylinder 3 and the first-stage piston cylinder 2 forms the second-stage cavity 31, the second-stage cavity 31 is filled with hydraulic oil, and the second-stage cavity 31 is divided into the rod cavity and the rodless cavity by the piston part of the second-stage piston cylinder 3. The first oil port 22 is arranged on the side wall of the first-stage piston cylinder 2 and is in communication with the rod cavity of the second-stage cavity 31, and a plurality of first oil ports 22 are arranged on the first-stage piston cylinder 2 and are uniformly distributed along the circumference of the first-stage piston cylinder 2; when the first-stage piston cylinder 2 is extended forward, the volume of the rod cavity of the first-stage cavity 21 is compressed, the oil in the first-stage cavity 21 enters the second-stage cavity 31 from the rodless cavity at the bottom of the piston of the second-stage piston cylinder 3 through the first oil port 22, and the second-stage piston cylinder 3 is pushed to move forward, so that the first-stage piston cylinder 2 and the second-stage piston cylinder 3 are synchronously extended.

[0021] The built-in displacement sensor 6 is installed in the second-stage piston cylinder 3, the sensor 6 is fixedly connected with the cylinder cover 11, and a sealing ring is installed between the sensor 6 and the cylinder cover 11. The detection rod of the sensor 6 is installed in the second-stage piston cylinder 3 and is used for indirectly detecting the displacement of the second-stage piston cylinder 3. The third-stage cavity 41 is formed between the sensor 6 and the second-stage piston cylinder 3, and the third-stage cavity 41 is filled with hydraulic oil. The sealing device is installed in the third-stage cavity 41 and comprises the spacer 4 and the sealing cylinder 5. The outer diameter of the spacer 4 is smaller than the inner diameter of the cylinder part of the second-stage piston cylinder 3, the outer diameter of the spacer 4 is equal to the inner diameter of the piston part of the second-stage piston cylinder 3, the gap between the spacer 4 and the cylinder part of the second-stage piston cylinder 3 is used as a passage one for hydraulic oil, the spacer 4 is fixedly connected with the piston part of the first-stage piston cylinder 2, and the spacer 4 is synchronously extended and contracted with the first-stage piston cylinder 2.

[0022] The sealing cylinder 5 is installed in the spacer 4, the end of the sealing cylinder 5 is fixedly installed on the cylinder cover 11, the outer diameter of the sealing cylinder 5 is equal to the inner diameter of the spacer 4, a seal is formed between the spacer 4 and the sealing cylinder 5, the inner diameter of the sealing cylinder 5 is greater than the outer diameter of the detection rod of the sensor 6, the gap between the sealing cylinder 5 and the sensor 6 is used as a passage two for hydraulic oil.

[0023] The magnetic ring 61 is installed between the end of the spacer 4 and the sealing cylinder 5, the magnetic ring 61 is in contact with the outer diameter of the sealing cylinder 5, the magnetic ring 61 cooperates with the detection rod of the sensor 6 and is used for detecting the displacement of the first-stage piston cylinder 2, the sensor 6 feeds back the detected data to the control system, and the control system can obtain the specific displacement of the second-stage piston cylinder 3 through simple calculation.

[0024] The second oil port 32 is provided in the cylinder and piston part of the secondary piston cylinder 3 and communicates the secondary cavity 31 and the tertiary cavity 41. The second oil port 32 is provided with multiple ports and is evenly distributed along the circumference of the secondary piston cylinder 3. The cylinder retracting oil port 7 communicates with the tertiary cavity. The oil port is located between the sealing cylinder 5 and the sensor 6. When the cylinder retracting action is needed, hydraulic oil is injected into the oil cylinder from the cylinder retracting oil port 7. The hydraulic oil enters the tertiary cavity 41 along the channel between the sealing cylinder 5 and the sensor 6. Then the hydraulic oil continuously enters the rod cavity of the secondary cavity 31 through the gap between the spacer cylinder 4 and the secondary piston cylinder 3 through the second oil port 32. Then the rodless cavity of the secondary cavity 31 is compressed. The hydraulic oil in the rodless cavity of the secondary cavity 31 continuously enters the rod cavity of the primary cavity 21 through the first oil port 22. At this time, the rodless cavity of the primary cavity 21 is compressed. The primary piston cylinder 2 synchronously performs the cylinder retracting action with the secondary piston cylinder 3 under the action of the hydraulic oil. At the same time, the sensor 6 can detect the displacement of the primary piston cylinder 2 in real time due to the cooperation of the magnetic ring 61 and the sensor 6 detection rod. The displacement signal is fed back to the control system. The control system accurately controls the flow and pressure of the hydraulic oil according to the feedback signal and indirectly calculates the displacement of the secondary piston cylinder 3, thereby realizing the accurate control of the cylinder retracting action of the primary piston cylinder 2.

[0025] The oil cylinder is filled with oil in the primary cavity 21, the secondary cavity 31 and the tertiary cavity 41 during production.

[0026] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A synchronous hydraulic cylinder, characterized in that, Includes a cylinder (1), a cylinder head (11) is provided at the bottom end of the cylinder (1), and a multi-stage piston cylinder and a displacement sensor (6) are provided inside the cylinder (1). A multi-stage linkage cavity is formed between the multi-stage piston cylinder and the displacement sensor (6). The multi-stage piston cylinder includes a first-stage piston cylinder (2) disposed inside the cylinder (1), and a second-stage piston cylinder (3) disposed inside the first-stage piston cylinder (2). The displacement sensor (6) is fixedly mounted on the cylinder head (11), and the detection end of the displacement sensor (6) extends into the interior of the secondary piston cylinder (3); The multi-stage linkage cavity includes a primary cavity (21) formed between the cylinder (1) and the primary piston cylinder (2), a secondary cavity (31) formed between the primary piston cylinder (2) and the secondary piston cylinder (3), and a tertiary cavity (41) formed between the secondary piston cylinder (3) and the displacement sensor; the cross-sectional areas of the primary cavity (21) and the secondary cavity (31) are equal. The multi-stage linkage chamber is divided into rod-type chambers and rodless chambers by the pistons of the corresponding stages.

2. A synchronous hydraulic cylinder according to claim 1, characterized in that, The side wall of the first-stage piston cylinder (2) is provided with a first oil port (22) that drives the first-stage cavity (21) and the second-stage cavity (31) to extend synchronously. The first oil port (22) connects the rod cavity of the first-stage cavity (21) and the rodless cavity of the second-stage cavity (31). There are multiple first oil ports (22), which are evenly distributed along the circumference of the first-stage piston cylinder (2).

3. A synchronous hydraulic cylinder according to claim 1, characterized in that, The secondary piston cylinder (3) is provided with a second oil port (32) that drives the primary chamber (21) and the secondary chamber (31) to retract synchronously. The second oil port (32) connects the tertiary chamber (41) and the rod chamber of the second-stage chamber (31).

4. A synchronous hydraulic cylinder according to claim 1, characterized in that, A sealing device is provided between the secondary piston cylinder (3) and the displacement sensor (6). The sealing device includes a partition cylinder (4). The end of the partition cylinder (4) is fixed to the piston part of the primary piston cylinder (2). A channel for hydraulic oil flow is left between the partition cylinder (4) and the secondary piston cylinder (3).

5. A synchronous hydraulic cylinder according to claim 4, characterized in that, The sealing device also includes a sealing cylinder (5), which is fixedly mounted on the cylinder head (11) and seals against the inner wall of the partition cylinder (4). A channel for hydraulic oil flow is left between the sealing cylinder (5) and the displacement sensor (6).

6. A synchronous hydraulic cylinder according to claim 4, characterized in that, A magnetic ring (61) for detecting the displacement of the first-stage piston cylinder (2) is provided between the partition cylinder (4) and the first-stage piston cylinder (2). The magnetic ring (61) is located on the piston part of the first-stage piston cylinder (2).

7. A synchronous hydraulic cylinder according to claim 4, characterized in that, The cylinder head (11) is provided with a cylinder extension port (8), which is connected to the rodless chamber of the primary chamber (21).

8. A synchronous hydraulic cylinder according to claim 5, characterized in that, The cylinder head (11) is provided with a cylinder shrinking oil port (7), which is connected to the third-stage chamber (41) through channel two.

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