Two-stage telescopic hydraulic cylinder

Abstract

The utility model belongs to the technical field of hydraulic oil cylinders, and provides a two-stage telescopic hydraulic cylinder which has a full-stroke displacement measuring function and is high in integration degree, the two-stage telescopic hydraulic cylinder comprises an outer cylinder body and a synchronous cylinder body, the outer cylinder body and the synchronous cylinder body are relatively fixed, a two-stage piston is movably arranged in the outer cylinder body, and the two-stage piston is movably arranged in the synchronous cylinder body. A secondary piston is movably arranged in the synchronous cylinder body, a primary piston is movably arranged in the secondary piston, a second synchronous sleeve is movably arranged in the synchronous cylinder body, a first synchronous sleeve is movably arranged in the second synchronous sleeve, the secondary piston and the second synchronous sleeve are relatively fixed, and the primary piston and the first synchronous sleeve are relatively fixed; a second detection part is further arranged in the outer cylinder body and used for sensing stroke information of the second-stage piston, and a first detection part is further arranged in the second synchronous sleeve and used for sensing stroke information of the first-stage piston.

Description

Technical Field

[0001] The present application belongs to the technical field of hydraulic cylinders, and in particular relates to a two-stage telescopic hydraulic cylinder. Background Art

[0002] As a hydraulic transmission element, hydraulic cylinders play an important role in the field of industrial machinery and equipment. As coal mine machinery and equipment continue to develop in the direction of automation and intelligence, hydraulic cylinders must have intelligent control and detection functions for motion and stroke parameters, and be able to be controlled by incorporating them into an intelligent centralized control system. At present, for single-piston rod hydraulic cylinders, cylinder stroke measurement and control can be achieved by installing a magnetostrictive sensor inside the cylinder; but for two-stage telescopic hydraulic cylinders, this is achieved by additional auxiliary installation of pull-rope displacement sensors, laser ranging sensors and other equipment. There is no product that can achieve full-stroke displacement measurement and control through the cylinder's own integrated design. Utility Model Content

[0003] Therefore, the technical problem to be solved by the present application is to provide a two-stage telescopic hydraulic cylinder with a full-stroke displacement measurement function and a high degree of integration.

[0004] In order to solve the above problems, the present application provides a two-stage telescopic hydraulic cylinder, comprising an outer cylinder body and a synchronous cylinder body, wherein the outer cylinder body is relatively fixed to the synchronous cylinder body, a secondary piston is movably provided in the outer cylinder body, a primary piston is movably provided in the secondary piston, a second synchronous sleeve is movably provided in the synchronous cylinder body, a first synchronous sleeve is movably provided in the second synchronous sleeve, the secondary piston is relatively fixed to the second synchronous sleeve, and the primary piston is relatively fixed to the first synchronous sleeve;

[0005] A second detection unit is also provided in the outer cylinder body, and the second detection unit is used to sense the stroke information of the secondary piston. A first detection unit is also provided in the second synchronous sleeve, and the first detection unit is used to sense the stroke information of the primary piston.

[0006] Optionally, both the first detection unit and the second detection unit are magnetostrictive displacement sensors.

[0007] Optionally, the second detection part includes a second waveguide tube and a second magnetic ring, the second waveguide tube is relatively fixed to the cylinder bottom of the outer cylinder body, and the second magnetic ring is relatively fixed to the top of the secondary piston.

[0008] Optionally, the first detection part includes a first waveguide tube and a first magnetic ring, the first waveguide tube is relatively fixed to one end of the second synchronization sleeve close to the cylinder bottom of the synchronization cylinder body, and the first magnetic ring is relatively fixed to one end of the first synchronization sleeve close to the cylinder bottom of the synchronization cylinder body.

[0009] Optionally, the two-stage telescopic hydraulic cylinder further includes a mounting seat, a first end of the mounting seat is connected to the outer cylinder body, and a second end of the mounting seat is connected to the synchronous cylinder body.

[0010] Optionally, the secondary telescopic hydraulic cylinder further includes a second mounting rod, a first end of the second mounting rod is connected to the secondary piston, and a second end of the second mounting rod is connected to the second synchronous sleeve.

[0011] Optionally, the secondary telescopic hydraulic cylinder further includes a first mounting rod, a first end of the first mounting rod is connected to the primary piston, and a second end of the first mounting rod is connected to the first synchronization sleeve.

[0012] Optionally, the secondary telescopic hydraulic cylinder also includes a first guide sleeve, which is arranged at one end of the secondary piston away from the cylinder bottom of the outer cylinder body, and the first guide sleeve is clearance-matched with the primary piston, and the first guide sleeve is used to limit the radial displacement of the primary piston.

[0013] Optionally, the secondary telescopic hydraulic cylinder also includes a second guide sleeve, which is arranged at the cylinder mouth of the outer cylinder body, and the second guide sleeve is clearance-matched with the secondary piston, and the second guide sleeve is used to limit the radial displacement of the secondary piston.

[0014] Optionally, the two-stage telescopic hydraulic cylinder also includes a signal processor, which is electrically connected to the first detection part and the second detection part respectively, and is used to receive a first signal transmitted by the first detection part and a second signal transmitted by the first detection part.

[0015] Beneficial Effects

[0016] The two-stage telescopic hydraulic cylinder provided in the embodiment of the utility model can detect the stroke information of the two-stage piston by arranging the second detection part in the outer cylinder body. By arranging the two-stage piston and the second synchronous sleeve to be relatively fixed, and the one-stage piston and the first synchronous sleeve to be relatively fixed, the synchronous movement of the two-stage piston and the second synchronous sleeve can be realized. The one-stage piston and the first synchronous sleeve move synchronously. The first detection part is arranged in the second synchronous sleeve to detect the stroke information of the first synchronous sleeve, and the stroke information of the synchronously moving one-stage piston can be determined, so that the two-stage telescopic hydraulic cylinder has a full-stroke displacement measurement function to meet the user's use requirements; at the same time, the second synchronous sleeve can be movably arranged in the synchronous cylinder body, and the synchronous cylinder body guides and protects the second synchronous sleeve, which can improve the use reliability of the second detection part; at the same time, the synchronous cylinder body is relatively fixed to the outer cylinder body, which can improve the integration degree of the two-stage telescopic hydraulic cylinder and reduce the installation space of the two-stage telescopic hydraulic cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a schematic structural diagram of a two-stage telescopic hydraulic cylinder according to an optional embodiment of the present application.

[0018] The reference numerals are as follows:

[0019] 1. Outer cylinder; 2. Secondary piston; 3. Primary piston; 4. Synchronous cylinder; 5. Second synchronous sleeve; 6. First synchronous sleeve; 7. First detection unit; 71. First waveguide tube; 72. First magnetic ring; 8. Second detection unit; 81. Second waveguide tube; 82. Second magnetic ring; 9. Mounting seat; 10. First mounting rod; 11. Second mounting rod; 12. First guide sleeve; 13. Second guide sleeve; 14. Signal processor. DETAILED DESCRIPTION

[0020] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0023] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0024] See also Figure 1As shown, according to an embodiment of the present application, a two-stage telescopic hydraulic cylinder is provided, including an outer cylinder body 1 and a synchronous cylinder body 4, the outer cylinder body 1 is relatively fixed to the synchronous cylinder body 4, a secondary piston 2 is movably provided in the outer cylinder body 1, a primary piston 3 is movably provided in the secondary piston 2, a second synchronous sleeve 5 is movably provided in the synchronous cylinder body 4, a first synchronous sleeve 6 is movably provided in the second synchronous sleeve 5, the secondary piston 2 and the second synchronous sleeve 5 are relatively fixed, and the primary piston 3 and the first synchronous sleeve 6 are relatively fixed; a second detection part 8 is also provided in the outer cylinder body 1, and the second detection part 8 is used to sense the stroke information of the secondary piston 2, and a first detection part 7 is also provided in the second synchronous sleeve 5, and the first detection part 7 is used to sense the stroke information of the primary piston 3.

[0025] The two-stage telescopic hydraulic cylinder provided in the embodiment of the utility model can detect the stroke information of the two-stage piston 2 by arranging the second detection part 8 in the outer cylinder body 1, and can realize synchronous movement of the two-stage piston 2 and the second synchronous sleeve 5 by arranging the two-stage piston 2 and the second synchronous sleeve 5 to be relatively fixed, and the one-stage piston 3 and the first synchronous sleeve 6 to be relatively fixed, and can realize synchronous movement of the one-stage piston 3 and the first synchronous sleeve 6, and can determine the stroke information of the synchronously moving one-stage piston 3 by arranging the first detection part 7 in the second synchronous sleeve 5 to detect the stroke information of the first synchronous sleeve 6, so that the two-stage telescopic hydraulic cylinder has a full-stroke displacement measurement function to meet the user's use requirements; at the same time, the second synchronous sleeve 5 can be movably arranged in the synchronous cylinder body 4, and the synchronous cylinder body 4 guides and protects the second synchronous sleeve 5, which can improve the use reliability of the second detection part 8; at the same time, the synchronous cylinder body 4 is relatively fixed to the outer cylinder body 1, which can improve the integration degree of the two-stage telescopic hydraulic cylinder and reduce the installation space of the two-stage telescopic hydraulic cylinder.

[0026] Among them, the two-stage telescopic hydraulic cylinder can be a hydraulic cylinder of a linear reciprocating type with a two-stage sleeve-shaped piston rod.

[0027] Among them, the secondary telescopic hydraulic cylinder includes an outer cylinder body 1, which is the body of the secondary telescopic hydraulic cylinder and can be used as the cylinder barrel of the secondary piston 2. A secondary working chamber is arranged in the outer cylinder body 1, and the secondary working chamber can be cylindrical. The secondary working chamber is open on one side away from the bottom of the cylinder, and a secondary piston 2 is movably arranged in the secondary working chamber.

[0028] Among them, the secondary piston 2 can be used as the cylinder of the primary piston 3, and a primary working chamber is provided in the secondary piston 2. The primary working chamber can be cylindrical, and the side of the primary working chamber away from the cylinder bottom is open, and the primary piston 3 is movably provided in the primary working chamber. It should be noted that a mounting hole is provided at the center of the primary piston 3, and the mounting hole also penetrates the head of the secondary piston 2 along the axial direction of the primary piston 3, and is used to accommodate the sensitive element of the second detection unit 8. In the embodiment of the present application, the mounting hole is used to accommodate the second waveguide 81.

[0029] Specifically, when the secondary telescopic hydraulic cylinder is working, the piston with the largest effective area begins to extend, and when it reaches the end point, the piston with the second largest effective area begins to extend, so as to obtain a very long working stroke. In the embodiment of the present application, the diameter of the primary piston 3 is smaller than the diameter of the secondary piston 2, that is, the secondary piston 2 begins to extend first, and when the secondary piston 2 reaches the end point, the primary piston 3 begins to extend.

[0030] Among them, the two-stage telescopic hydraulic cylinder also includes a synchronous cylinder body 4, which can be a hollow structure with one end open, and a second synchronous sleeve 5 is movably arranged in the synchronous cylinder body 4. The second synchronous sleeve 5 can also be a hollow structure with one end open, and a first synchronous sleeve 6 is movably arranged in the second synchronous sleeve 5. It should be noted that the first synchronous sleeve 6 is also a hollow structure with one end open, and the opening direction of the synchronous cylinder body 4 is the same as the opening direction of the second synchronous sleeve 5, and opposite to the opening direction of the first synchronous sleeve 6. The first synchronous sleeve 6 is a hollow structure with one end open for accommodating the sensitive element of the first detection unit 7. In the embodiment of the present application, the sensitive element of the first detection unit 7 is a first waveguide tube 71.

[0031] Specifically, the synchronous cylinder body 4 is relatively fixed to the outer cylinder body 1, the second synchronous sleeve 5 is relatively fixed to the secondary piston 2, and the first synchronous sleeve 6 is relatively fixed to the primary piston 3. It should be noted that the second synchronous sleeve 5 is used to characterize the working state of the secondary piston 2. When the secondary piston 2 reciprocates in the outer cylinder body 1, it can synchronously drive the second synchronous sleeve 5 to reciprocate in the synchronous cylinder body 4; the first synchronous sleeve 6 is used to characterize the working state of the primary piston 3. When the primary piston 3 reciprocates in the secondary piston 2, it can synchronously drive the first synchronous sleeve 6 to reciprocate in the second synchronous sleeve 5. In this application, the relative displacement of the first synchronous sleeve 6 and the second synchronous sleeve 5 can characterize the relative displacement of the primary piston 3 and the secondary piston 2.

[0032] Among them, the two-stage telescopic hydraulic cylinder also includes a first detection part 7 and a second detection part 8. The first detection part 7 is arranged in the second synchronous sleeve 5, and the first detection part 7 is used to sense the stroke information of the first synchronous sleeve 6. Since the first synchronous sleeve 6 moves synchronously with the first-stage piston 3, the stroke measurement of the first-stage piston 3 can be realized; the second detection part 8 is arranged in the outer cylinder body 1, and the second detection part 8 is used to sense the stroke information of the second-stage piston 2, and the stroke measurement of the second-stage piston 2 can be realized.

[0033] The stroke information of the primary piston 3 may be the relative displacement information between the primary piston 3 and the secondary piston 2 .

[0034] The stroke information of the secondary piston 2 may be the relative displacement information between the secondary piston 2 and the outer cylinder body 1 .

[0035] Specifically, the first detection part 7 and the second detection part 8 can be magnetostrictive displacement sensors, rope displacement sensors or laser displacement sensors, etc. In the embodiment of the present application, the first detection part 7 and the second detection part 8 are both magnetostrictive displacement sensors. Compared with rope displacement sensors or laser displacement sensors, magnetostrictive displacement sensors can be used in extremely harsh industrial environments such as high temperature, high pressure and high vibration because the sensitive element is non-contact, and are not easily affected by oil stains, solutions, dust or other pollution. At the same time, even if the detection is repeated continuously, it will not cause any wear to the magnetostrictive displacement sensor, which can greatly improve the reliability and service life of the detection and flexibly meet the use of coal mine workers.

[0036] In some possible implementations provided in this application, see Figure 1 As shown, the second detection part 8 includes a second waveguide tube 81 and a second magnetic ring 82 . The second waveguide tube 81 is relatively fixed to the bottom of the outer cylinder body 1 , and the second magnetic ring 82 is relatively fixed to the top of the secondary piston 2 .

[0037] The second waveguide tube 81 is fixedly mounted on the cylinder body of the outer cylinder body 1 . The second waveguide tube 81 extends along the axial direction of the secondary piston 2 . Current pulses are transmitted in the second waveguide tube 81 , thereby generating a circumferential magnetic field outside the second waveguide tube 81 .

[0038] The second magnetic ring 82 can be installed on the piston head of the secondary piston 2 by screws. In the embodiment of the present application, the second magnetic ring 82 and the top of the secondary piston 2 are located in the same plane. The top of the secondary piston 2 is the piston top.

[0039] Specifically, when the secondary piston 2 reciprocates in the outer cylinder body 1, the second magnetic ring 82 is located on the outer peripheral side of the second waveguide tube 81 and reciprocates along the axial direction of the second waveguide tube 81. It can be understood that when the circumferential magnetic field outside the second waveguide tube 81 and the magnetic field generated by the movable second magnetic ring 82 sleeved on the second waveguide tube 81 as a position change intersect, due to the effect of magnetostriction, a strain mechanical wave pulse signal that can be detected will be generated in the second waveguide tube 81, thereby achieving the purpose of measuring the stroke displacement of the secondary piston 2.

[0040] In some possible implementations provided in this application, see Figure 1 As shown, the first detection part 7 includes a first waveguide tube 71 and a first magnetic ring 72. The first waveguide tube 71 is relatively fixed to one end of the second synchronous sleeve 5 close to the cylinder bottom of the synchronous cylinder body 4, and the first magnetic ring 72 is relatively fixed to one end of the first synchronous sleeve 6 close to the cylinder bottom of the synchronous cylinder body 4.

[0041] The first waveguide tube 71 is fixedly mounted at the bottom of the second synchronous sleeve 5 . The first waveguide tube 71 extends along the axial direction of the first synchronous sleeve 6 . Current pulses are transmitted in the first waveguide tube 71 , thereby generating a circumferential magnetic field outside the first waveguide tube 71 .

[0042] Among them, the first magnetic ring 72 can be installed on the end of the first synchronous sleeve 6 close to the bottom of the second synchronous sleeve 5 by screws. In the embodiment of the present application, the end surface of the first magnetic ring 72 and the end of the first synchronous sleeve 6 close to the bottom of the second synchronous sleeve 5 are located in the same plane.

[0043] Specifically, when the primary piston 3 reciprocates in the secondary piston 2, it can synchronously drive the first synchronous sleeve 6 to reciprocate in the second synchronous sleeve 5. At this time, the first magnetic ring 72 is located on the outer peripheral side of the first waveguide tube 71 and reciprocates along the axial direction of the first waveguide tube 71. It can be understood that when the circumferential magnetic field outside the first waveguide tube 71 and the magnetic field generated by the movable first magnetic ring 72 sleeved on the first waveguide tube 71 as a position change intersect, due to the effect of magnetostriction, a detectable strain mechanical wave pulse signal is generated in the first waveguide tube 71, so as to achieve the purpose of measuring the stroke displacement of the first synchronous sleeve 6, that is, the stroke displacement of the primary piston 3.

[0044] In some possible implementations provided in this application, see Figure 1 As shown, the two-stage telescopic hydraulic cylinder also includes a mounting seat 9 , a first end of the mounting seat 9 is connected to the outer cylinder body 1 , and a second end of the mounting seat 9 is connected to the synchronous cylinder body 4 .

[0045] By providing the mounting seat 9, the outer cylinder body 1 and the synchronous cylinder body 4 can be fixed, thereby improving the integration level of the secondary telescopic hydraulic cylinder and reducing the installation space of the secondary telescopic hydraulic cylinder.

[0046] The outer cylinder body 1 and the synchronous cylinder body 4 are respectively arranged on both sides of the mounting seat 9 , and the mounting seat 9 is used to connect the outer cylinder body 1 and the synchronous cylinder body 4 .

[0047] Specifically, the first end of the mounting seat 9 is connected to the outer cylinder body 1, and the second end of the mounting seat 9 is connected to the synchronous cylinder body 4. The connection method can be bolt connection or welding, etc., and this application does not make further limitations.

[0048] In some possible implementations provided in this application, see Figure 1 As shown, the two-stage telescopic hydraulic cylinder also includes a first mounting rod 10 and a second mounting rod 11, the first end of the second mounting rod 11 is connected to the secondary piston 2, and the second end of the second mounting rod 11 is connected to the second synchronous sleeve 5; the two-stage telescopic hydraulic cylinder also includes a first mounting rod 10, the first end of the first mounting rod 10 is connected to the primary piston 3, and the second end of the first mounting rod 10 is connected to the first synchronous sleeve 6.

[0049] By setting the second mounting rod 11, the secondary piston 2 and the second synchronous sleeve 5 can be fixed, and by setting the first mounting rod 10, the primary piston 3 and the first synchronous sleeve 6 can be fixed, so that the relative displacement of the first synchronous sleeve 6 and the second synchronous sleeve 5 can represent the relative displacement of the primary piston 3 and the secondary piston 2.

[0050] The first mounting rod 10 and the second mounting rod 11 may be rectangular metal rods or cylindrical metal rods, etc., and this application does not make any further limitations.

[0051] Specifically, the primary piston 3 and the first synchronous sleeve 6 are arranged on both sides of the first mounting rod 10 along the length direction of the first mounting rod 10, the first end of the first mounting rod 10 is connected to the primary piston 3, and the second end of the first mounting rod 10 is connected to the first synchronous sleeve 6; the secondary piston 2 and the second synchronous sleeve 5 are arranged on both sides of the second mounting rod 11 along the length direction of the second mounting rod 11, the first end of the second mounting rod 11 is connected to the secondary piston 2, and the second end of the second mounting rod 11 is connected to the second synchronous sleeve 5.

[0052] In some possible implementations provided in this application, see Figure 1 As shown, the secondary telescopic hydraulic cylinder also includes a first guide sleeve 12, which is arranged at one end of the secondary piston 2 away from the cylinder bottom of the outer cylinder body 1, and the first guide sleeve 12 is clearance-matched with the primary piston 3, and the first guide sleeve 12 is used to limit the radial displacement of the primary piston 3.

[0053] The first guide sleeve 12 is provided to guide the reciprocating motion of the primary piston 3 in the secondary piston 2, and at the same time, radial displacement of the primary piston 3 can be avoided, ensuring that the primary piston 3 stably reciprocates in the secondary piston 2, thereby improving the working stability of the secondary telescopic hydraulic cylinder.

[0054] Among them, the first guide sleeve 12 is roughly annular, and the first guide sleeve 12 is fixedly installed at the opening of the first-stage working chamber. The outer wall of the first guide sleeve 12 fits with the inner wall of the first-stage working chamber, and the inner wall of the first guide sleeve 12 fits with the outer wall of the first-stage piston 3.

[0055] Specifically, the inner wall of the first guide sleeve 12 is clearance-matched with the outer wall of the primary piston 3 , which can limit the radial displacement of the primary piston 3 without hindering the movement of the primary piston 3 relative to the second piston.

[0056] It should be noted that the first guide sleeve 12 also has the function of sealing the primary working chamber.

[0057] In some possible implementations provided in this application, see Figure 1As shown, the secondary telescopic hydraulic cylinder also includes a second guide sleeve 13, which is arranged at the cylinder mouth of the outer cylinder body 1, and the second guide sleeve 13 is clearance-matched with the secondary piston 2, and the second guide sleeve 13 is used to limit the radial displacement of the secondary piston 2.

[0058] The second guide sleeve 13 is provided to guide the movement of the secondary piston 2 in the outer cylinder body 1, and at the same time, radial displacement of the secondary piston 2 can be avoided, ensuring that the secondary piston 2 stably reciprocates in the outer cylinder body 1, thereby improving the working stability of the secondary telescopic hydraulic cylinder.

[0059] Among them, the second guide sleeve 13 is roughly annular and is fixedly installed at the opening of the secondary working chamber. The outer wall of the second guide sleeve 13 fits with the inner wall of the secondary working chamber, and the inner wall of the second guide sleeve 13 fits with the outer wall of the secondary piston 2.

[0060] Specifically, the inner wall of the second guide sleeve 13 is clearance-matched with the outer wall of the secondary piston 2 , which can limit the radial displacement of the secondary piston 2 without hindering the movement of the secondary piston 2 relative to the outer cylinder body 1 .

[0061] It should be noted that the second guide sleeve 13 also has the function of sealing the secondary working chamber.

[0062] In some possible implementations provided in this application, see Figure 1 As shown, the two-stage telescopic hydraulic cylinder also includes a signal processor 14, which is electrically connected to the first detection part 7 and the second detection part 8 respectively, and the signal processor 14 is used to receive a first signal transmitted by the first detection part 7 and a second signal transmitted by the first detection part 7.

[0063] The signal processor 14 may be a digital signal processor 14 (DSP).

[0064] Specifically, the signal processor 14 is electrically connected to the first detection unit 7 and the second detection unit 8, respectively. The signal processor 14 receives the first signal transmitted by the first detection unit 7 to obtain the stroke data of the primary piston 3, and the signal processor 14 receives the second signal transmitted by the second detection unit 8 to obtain the stroke data of the secondary piston 2. It should be noted that the signal processor 14 superimposes the stroke data of the primary piston 3 and the stroke data of the secondary piston 2 to obtain the total stroke parameter of the secondary telescopic hydraulic cylinder.

[0065] The two-stage telescopic hydraulic cylinder provided in the embodiment of the utility model can detect the stroke information of the two-stage piston 2 by arranging the second detection part 8 in the outer cylinder body 1, and can realize synchronous movement of the two-stage piston 2 and the second synchronous sleeve 5 by arranging the two-stage piston 2 and the second synchronous sleeve 5 to be relatively fixed, and the one-stage piston 3 and the first synchronous sleeve 6 to be relatively fixed, and can realize synchronous movement of the one-stage piston 3 and the first synchronous sleeve 6, and can determine the stroke information of the synchronously moving one-stage piston 3 by arranging the first detection part 7 in the second synchronous sleeve 5 to detect the stroke information of the first synchronous sleeve 6, so that the two-stage telescopic hydraulic cylinder has a full-stroke displacement measurement function to meet the user's use requirements; at the same time, the second synchronous sleeve 5 can be movably arranged in the synchronous cylinder body 4, and the synchronous cylinder body 4 guides and protects the second synchronous sleeve 5, which can improve the use reliability of the second detection part 8; at the same time, the synchronous cylinder body 4 is relatively fixed to the outer cylinder body 1, which can improve the integration degree of the two-stage telescopic hydraulic cylinder and reduce the installation space of the two-stage telescopic hydraulic cylinder.

[0066] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0067] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A two-stage telescopic hydraulic cylinder, characterized in that: The invention comprises an outer cylinder body (1) and a synchronous cylinder body (4), wherein the outer cylinder body (1) and the synchronous cylinder body (4) are relatively fixed, a secondary piston (2) is movably provided in the outer cylinder body (1), a primary piston (3) is movably provided in the secondary piston (2), a second synchronous sleeve (5) is movably provided in the synchronous cylinder body (4), a first synchronous sleeve (6) is movably provided in the second synchronous sleeve (5), the secondary piston (2) and the second synchronous sleeve (5) are relatively fixed, and the primary piston (3) and the first synchronous sleeve (6) are relatively fixed; A second detection unit (8) is also provided in the outer cylinder body (1), and the second detection unit (8) is used to sense the stroke information of the secondary piston (2). A first detection unit (7) is also provided in the second synchronous sleeve (5), and the first detection unit (7) is used to sense the stroke information of the primary piston (3).

2. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The first detection part (7) and the second detection part (8) are both magnetostrictive displacement sensors.

3. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The second detection part (8) comprises a second waveguide tube (81) and a second magnetic ring (82); the second waveguide tube (81) is relatively fixed to the bottom of the outer cylinder body (1); and the second magnetic ring (82) is relatively fixed to the top of the secondary piston (2).

4. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The first detection part (7) comprises a first waveguide tube (71) and a first magnetic ring (72); the first waveguide tube (71) and one end of the second synchronous sleeve (5) close to the cylinder bottom of the synchronous cylinder body (4) are relatively fixed; the first magnetic ring (72) and one end of the first synchronous sleeve (6) close to the cylinder bottom of the synchronous cylinder body (4) are relatively fixed.

5. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The two-stage telescopic hydraulic cylinder also includes a mounting seat (9), a first end of the mounting seat (9) is connected to the outer cylinder body (1), and a second end of the mounting seat (9) is connected to the synchronous cylinder body (4).

6. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The two-stage telescopic hydraulic cylinder also includes a second mounting rod (11), a first end of the second mounting rod (11) being connected to the two-stage piston (2), and a second end of the second mounting rod (11) being connected to the second synchronous sleeve (5).

7. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The two-stage telescopic hydraulic cylinder also includes a first mounting rod (10), a first end of the first mounting rod (10) being connected to the first-stage piston (3), and a second end of the first mounting rod (10) being connected to the first synchronization sleeve (6).

8. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The secondary telescopic hydraulic cylinder further comprises a first guide sleeve (12), the first guide sleeve (12) being arranged at one end of the secondary piston (2) away from the cylinder bottom of the outer cylinder body (1), the first guide sleeve (12) being in clearance fit with the primary piston (3), and the first guide sleeve (12) being used to limit the radial displacement of the primary piston (3).

9. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The two-stage telescopic hydraulic cylinder also includes a second guide sleeve (13), which is arranged at the cylinder mouth of the outer cylinder body (1), and the second guide sleeve (13) is clearance-matched with the two-stage piston (2), and the second guide sleeve (13) is used to limit the radial displacement of the two-stage piston (2).

10. The two-stage telescopic hydraulic cylinder according to claim 1, characterized in that: The two-stage telescopic hydraulic cylinder also includes a signal processor (14), the signal processor (14) being electrically connected to the first detection part (7) and the second detection part (8) respectively, and the signal processor (14) being used to receive a first signal transmitted by the first detection part (7) and a second signal transmitted by the first detection part (7).

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