A multi-cylinder sequential telescopic hydraulic system for a folding arm truck crane

Abstract

A multi-cylinder sequential telescopic hydraulic system for a folding arm truck crane. It relates to the field of engineering structures, and in particular to a multi-cylinder sequential telescopic hydraulic system for a folding arm truck crane. A multi-cylinder sequential telescopic hydraulic system for a folding arm truck crane with a compact structure and a stable hydraulic system is proposed. It includes a first hydraulic cylinder, a first center pipe, a first-level two-position two-way reversing valve and a first non-return valve, a second hydraulic cylinder and a three-position four-way reversing valve; one end of the first center pipe is fixedly connected to the bottom of the cylinder body of the first hydraulic cylinder, and the other end extends into the center hole of the first piston rod of the first hydraulic cylinder, and is connected to the first piston rod in a sliding seal; the first center pipe and the first center pipe are respectively hollow tubes with one end closed. The present invention has the characteristics of compact structure and stable hydraulic system.

Description

Technical Field

[0001] The invention relates to the field of engineering structures, in particular to a multi-cylinder sequential telescopic hydraulic system for a folding arm type truck-mounted crane. Background Art

[0002] At present, the boom extension and retraction method of folding-arm truck cranes is mostly synchronous extension and retraction. However, as the truck cranes gradually develop towards large-scale, the number of boom sections increases, and synchronous extension and retraction is no longer the best extension and retraction method. With the development of the market and technology, sequential extension and retraction has gradually become the mainstream extension and retraction method of multi-section folding-arm truck cranes. At present, the domestic sequential extension and retraction hydraulic system mainly realizes the sequential extension and retraction function through one-way sequential valves. However, as the number of booms increases, the number of corresponding one-way sequential valves will increase, which will cause the system pressure to be too high. At the same time, this pressure-controlled sequential extension and retraction method is not stable. Summary of the invention

[0003] In view of the above problems, the present invention proposes a multi-cylinder sequential telescopic hydraulic system for a folding arm type truck crane which has a compact structure and a stable hydraulic system.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: comprising a first hydraulic cylinder, a first central tube, a first-stage two-position two-way reversing valve and a first one-way valve, a second hydraulic cylinder and a three-position four-way reversing valve;

[0005] One end of the first center tube is fixedly connected to the bottom of the cylinder body of the first hydraulic cylinder, and the other end extends into the center hole 1 of the first piston rod of the first hydraulic cylinder and is slidably and sealingly connected to the first piston rod;

[0006] The bottom of the cylinder body on one side of the rodless chamber of the first hydraulic cylinder is provided with an A1 oil port and a B1 oil port respectively connected to the three-position four-way reversing valve;

[0007] The inlet end of the first check valve is connected to the A1 oil port, and the outlet end thereof is connected to the rodless chamber of the first hydraulic cylinder; the first-stage two-position two-way reversing valve is connected to both ends of the first check valve;

[0008] One end of the B1 oil port is connected to the C1 oil port in the first central tube, and the other end is connected to the three-position four-way reversing valve;

[0009] The first piston rod is provided with a D1 oil port and an E1 oil port;

[0010] The D1 oil port is adapted to the C1 oil port; the D1 oil port is connected to the A2 oil port at the bottom of the cylinder body of the second hydraulic cylinder through a pipeline;

[0011] The E1 oil port is connected with the H2 oil port on the end cover of the second hydraulic cylinder through the oil circuit in the first piston rod; after the first piston rod is fully extended, the E1 oil port is connected with the F1 oil port on the end cover of the first hydraulic cylinder; the F1 oil port is connected with the three-position four-way reversing valve through the H1 oil port on the end cover of the first hydraulic cylinder; the H1 oil port is connected with the rod chamber of the first hydraulic cylinder.

[0012] Also included is a third hydraulic cylinder;

[0013] The second hydraulic cylinder is provided with a two-stage two-position two-way reversing valve, a second one-way valve and a second center pipe;

[0014] The inlet end of the second one-way valve is connected to the A2 oil port, and the other end is connected to the rodless chamber of the second hydraulic cylinder;

[0015] The secondary two-position two-way reversing valve is connected to both ends of the second one-way valve;

[0016] One end of the second center tube is fixedly connected to the bottom of the cylinder body of the second hydraulic cylinder, and the other end extends into the second center hole of the second piston rod of the second hydraulic cylinder and is slidably and sealingly connected to the second piston rod;

[0017] The second center tube is provided with a C2 oil port, and the C2 oil port is connected to the D1 oil port through the B2 oil port at the bottom of the cylinder body of the second hydraulic cylinder;

[0018] The second piston rod is provided with a D2 oil port and an E2 oil port;

[0019] The D2 oil port is adapted to the C2 oil port; the D2 oil port is connected to the A3 oil port at the bottom of the cylinder body of the third hydraulic cylinder through a pipeline;

[0020] The E2 oil port is connected with the B3 oil port on the end cover of the third hydraulic cylinder through the oil circuit in the second piston rod; after the second piston rod is fully extended, the E2 oil port is connected with the F2 oil port on the end cover of the second hydraulic cylinder; the F2 oil port is connected with the E1 oil port through the H2 oil port on the end cover of the second hydraulic cylinder; the H2 oil port is connected with the rod chamber of the second hydraulic cylinder.

[0021] The first central tube and the second central tube are respectively hollow tubes with one end closed.

[0022] Due to the adoption of the above technical solution, the technical progress achieved in this case is: through the improvement of the hydraulic cylinder structure, when the boom is extended, the first, second and third hydraulic cylinders are sequentially extended, and when it is retracted, the third, second and first hydraulic cylinders are sequentially retracted, and the control system is stable. Both extension and retraction are controlled by stroke, and there is no pressure control, so the system pressure is small and the energy loss is small. The present invention has the characteristics of compact structure and stable hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the hydraulic principle structure of the present invention.

[0024] Figure 2 This is a schematic diagram of the hydraulic principle structure during the extension action.

[0025] Figure 3 This is a schematic diagram of the hydraulic principle structure during the retraction action;

[0026] In the figure, 1 is the first hydraulic cylinder, 2 is the second hydraulic cylinder, 3 is the third hydraulic cylinder, 4 is the first-stage two-position two-way reversing valve, 5 is the second-stage two-position two-way reversing valve, 6 is the first one-way valve, 7 is the second one-way valve, 8 is the first piston rod, 9 is the second piston rod, 10 is the third piston rod, 11 is the first center tube, 12 is the second center tube, and 13 is the three-position four-way reversing valve. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings:

[0028] like Figure 1-3 As shown, 1. A multi-cylinder sequential telescopic hydraulic system of a folding arm truck crane, characterized in that it includes a first hydraulic cylinder 1, a first central pipe 11, a first-stage two-position two-way reversing valve 4 and a first one-way valve 6, a second hydraulic cylinder 2 and a three-position four-way reversing valve 13;

[0029] One end of the first center tube 11 is fixedly connected to the bottom of the cylinder body of the first hydraulic cylinder 1, and the other end extends into the center hole 1 of the first piston rod 8 of the first hydraulic cylinder 1 and is slidably and sealedly connected to the first piston rod 8;

[0030] The bottom of the cylinder body on the rodless chamber side of the first hydraulic cylinder 1 is provided with an A1 oil port and a B1 oil port respectively connected to the three-position four-way reversing valve 13;

[0031] The inlet end of the first check valve 6 is connected to the A1 oil port, and the outlet end thereof is connected to the rodless chamber of the first hydraulic cylinder 1; the first-stage two-position two-way reversing valve 4 is connected to both ends of the first check valve 6;

[0032] One end of the B1 oil port is connected to the C1 oil port in the first central tube 11, and the other end is connected to the three-position four-way reversing valve 13;

[0033] The first piston rod 8 is provided with a D1 oil port and an E1 oil port;

[0034] The D1 oil port is matched with the C1 oil port; after the first piston rod 8 is fully extended, the C1 oil port on the first piston rod 8 is connected with the D1 oil port; the D1 oil port is connected with the A2 oil port at the bottom of the cylinder body of the second hydraulic cylinder through a pipeline; the A2 oil port is connected with the rodless chamber of the first hydraulic cylinder 1;

[0035] The E1 oil port is connected to the H2 oil port on the end cover of the second hydraulic cylinder through the oil circuit in the first piston rod 8; after the first piston rod 8 is fully extended, the E1 oil port is connected to the F1 oil port on the end cover of the first hydraulic cylinder 1; the F1 oil port is connected to the three-position four-way reversing valve 13 through the H1 oil port on the end cover of the first hydraulic cylinder 1; the H1 oil port is connected to the rod chamber of the first hydraulic cylinder 1.

[0036] Also includes a third hydraulic cylinder 3;

[0037] The second hydraulic cylinder 2 is provided with a two-stage two-position two-way reversing valve 5, a second one-way valve 7 and a second center pipe 12;

[0038] The inlet end of the second one-way valve 7 is connected to the A2 oil port, and the other end is connected to the rodless chamber of the second hydraulic cylinder 2;

[0039] The two-stage two-position two-way reversing valve 5 is connected to both ends of the second one-way valve 7;

[0040] One end of the second center tube 12 is fixedly connected to the bottom of the cylinder body of the second hydraulic cylinder 2, and the other end extends into the second center hole of the second piston rod (9) of the second hydraulic cylinder 2 and is slidably and sealingly connected to the second piston rod 9;

[0041] The second center tube 12 is provided with a C2 oil port, and the C2 oil port is connected to the D1 oil port through the B2 oil port at the bottom of the cylinder body of the second hydraulic cylinder 2;

[0042] The second piston rod 9 is provided with a D2 oil port and an E2 oil port;

[0043] The D2 oil port is matched with the C2 oil port; after the second piston rod 9 is fully extended, the C2 oil port on the second piston rod 9 is connected with the D2 oil port; the D2 oil port is connected with the A3 oil port at the bottom of the cylinder body of the third hydraulic cylinder through a pipeline; the A3 oil port is connected with the rodless chamber of the second hydraulic cylinder 2;

[0044] The E2 oil port is connected to the B3 oil port on the end cover of the third hydraulic cylinder 3 through the oil circuit in the second piston rod 9; after the second piston rod 9 is fully extended, the E2 oil port is connected to the F2 oil port on the end cover of the second hydraulic cylinder 2; the F2 oil port is connected to the E1 oil port through the H2 oil port on the end cover of the second hydraulic cylinder 2; the H2 oil port is connected to the rod chamber of the second hydraulic cylinder 2.

[0045] The first central tube 11 and the second central tube 12 are respectively hollow tubes with one end closed.

[0046] Specific usage:

[0047] When the folding arm crane is extending, the three-position four-way reversing valve 13 works in the right position, and the oil flows through the A1 oil port at one end of the rodless chamber of the first hydraulic cylinder 1 and the first one-way valve to the rodless chamber of the first hydraulic cylinder 1. The first hydraulic cylinder 1 extends. When the first piston rod 8 is not fully extended, the oil port C1 oil port opened in the first center tube 11 and the oil port D1 oil port opened in the first piston rod 8 cannot be connected, so the oil cannot reach the rodless chambers of the second hydraulic cylinder 2 and the third hydraulic cylinder 3, and the other hydraulic cylinders cannot be extended. The oil in the rod chamber of the first hydraulic cylinder 1 flows back to the oil tank through the H1 oil port and the three-position four-way reversing valve 13 , after the first piston rod 8 is fully extended, the oil port C1 opened in the first center tube 11 is connected with the oil port D1 opened in the first piston rod 8, and the oil flows through the B1 oil port and the oil circuit in the center tube, the C1 oil port, the D1 oil port, the oil circuit in the piston rod, and the oil pipe to the A2 oil port and the B2 oil port on the rodless chamber side of the second hydraulic cylinder 2. The oil flows to the rodless chamber of the second hydraulic cylinder 2 through the A2 oil port and the second one-way valve 7. Since the first hydraulic cylinder 1 is fully extended, the E1 oil port on the first piston rod is connected with the F1 oil port on the cylinder head. Therefore, the oil in the rod chamber of the second hydraulic cylinder 2 flows through the H2 oil port, the oil circuit in the first piston rod, The oil flows back to the oil tank through the E1 oil port, F1 oil port, H1 oil port, and the three-position four-way reversing valve 13, and the second hydraulic cylinder 2 extends. When the second piston rod 9 is not fully extended, the D2 oil port opened on the second piston rod 9 is not connected to the C2 oil port opened in the second center tube 12, so the oil cannot enter the rodless cavity of the third hydraulic cylinder 3, and the third hydraulic cylinder 3 cannot extend. When the second piston rod 9 is fully extended, the D2 oil port opened on the second piston rod 9 is connected to the C2 oil port opened in the second center tube, and the oil flows through the B2 oil port, the second center tube 12, the C2 oil port, the D2 oil port, and the second piston rod 9. The internal oil circuit and oil pipe flow to the A3 oil port on the rodless chamber side of the third hydraulic cylinder 3. Since the first hydraulic cylinder 1 and the second hydraulic cylinder 2 are fully extended, the E1 oil port on the first piston rod 8 is connected with the F1 oil port on the cylinder cover, and the E2 oil port on the second piston rod 9 is connected with the F2 oil port on the cylinder cover. Therefore, the oil in the rod chamber of the third hydraulic cylinder 3 flows through the B3 oil port, oil pipe, the internal oil circuit of the second piston rod 9, the E2 oil port, the F2 oil port, the H2 oil port, the internal oil circuit of the first piston rod 8, the E1 oil port, the F1 oil port, the H1 oil port, and the three-position four-way reversing valve 13 and flows back to the oil tank, realizing the sequential extension action of the first, second and third hydraulic cylinders.

[0048] When the folding arm crane is retracting, the three-position four-way reversing valve 13 works in the left position. At the beginning of the retraction action, the three hydraulic cylinders are all in a fully extended state. The second hydraulic cylinder 2 is not in a fully retracted position and cannot hit the first-level two-position two-way reversing valve 4, so the valve is in a closed state. The third hydraulic cylinder 3 is not in a fully retracted position and cannot hit the second-level two-position two-way reversing valve 4, so the valve is also in a closed state. Therefore, the oil in the rodless chamber of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 cannot pass through the two The oil in the rodless cavity of the third hydraulic cylinder flows through the A3 oil port, the D2 oil port in the second piston rod 9, the C2 oil port, the second center tube 12, the B2 oil port, the oil circuit in the first piston rod 8, the H2 oil port, the F2 oil port, the E2 oil port, the B3 oil port in the second piston rod 9, and the oil pipe. , D1 oil port, C1 oil port, the first center pipe 11, B1 oil port, three-position four-way reversing valve 13 flow back to the oil tank, the third hydraulic cylinder 3 retracts, when the third hydraulic cylinder is fully retracted, the third piston rod 10 hits the secondary two-position two-way reversing valve 4, the valve opens the oil circuit to connect, at this time, the oil flows to the rod chamber of the second hydraulic cylinder 2 through the H1 oil port, F1 oil port, E1 oil port, the oil circuit in the first piston rod 8, and the H2 oil port, the oil in the rodless chamber of the second hydraulic cylinder 2 flows through the secondary two-position two-way reversing valve 4 and A2 oil port , the oil in the first piston rod 8, the C1 oil port, the D1 oil port, the first center tube 11, the B1 oil port, the three-position four-way reversing valve 13 flows back to the oil tank, and the second hydraulic cylinder 2 retracts. When the second hydraulic cylinder 2 is fully retracted, the second piston rod 9 hits the first-level two-position two-way reversing valve 3, and the valve opens the oil circuit to connect. At this time, the oil flows to the rod chamber of the first hydraulic cylinder 1 through the H1 oil port, and the oil in the rodless chamber of the first hydraulic cylinder 1 flows back to the oil tank through the first-level two-position two-way reversing valve 3, the A1 oil port, and the three-position four-way reversing valve 13. The third, second, and first hydraulic cylinders are retracted in sequence.

[0049] The hydraulic system of the present invention is not limited to three hydraulic cylinders, and the number of booms can be set according to actual conditions.

[0050] In summary, the present invention can realize the extension action in the order of first, second, and third, and the retraction action in the order of third, second, and first by modifying the design of the hydraulic cylinder structure, thereby eliminating the disadvantages of pressure control, reducing the system pressure compared to the one-way sequential valve-controlled sequential telescopic hydraulic system, and improving the stability of the telescopic sequence.

Claims

1. A multi-cylinder sequential telescopic hydraulic system for a folding arm truck crane, characterized in that: It comprises a first hydraulic cylinder (1), a first central tube (11), a first-stage two-position two-way reversing valve (4) and a first one-way valve (6), a second hydraulic cylinder (2) and a three-position four-way reversing valve (13); One end of the first center tube (11) is fixedly connected to the bottom of the cylinder body of the first hydraulic cylinder (1), and the other end extends into a center hole 1 of the first piston rod (8) of the first hydraulic cylinder (1) and is slidably and sealingly connected to the first piston rod (8); The bottom of the cylinder body on one side of the rodless chamber of the first hydraulic cylinder (1) is provided with an A1 oil port and a B1 oil port respectively connected to the three-position four-way reversing valve (13); The inlet end of the first one-way valve (6) is in communication with the A1 oil port, and the outlet end thereof is in communication with the rodless chamber of the first hydraulic cylinder (1); the first-stage two-position two-way reversing valve (4) is connected to both ends of the first one-way valve (6); One end of the B1 oil port is in communication with the C1 oil port in the first central tube (11), and the other end is in communication with the three-position four-way reversing valve (13); The first piston rod (8) is provided with a D1 oil port and an E1 oil port; The D1 oil port is adapted to the C1 oil port; the D1 oil port is connected to the A2 oil port at the bottom of the cylinder body of the second hydraulic cylinder through a pipeline; The E1 oil port is connected to the H2 oil port on the end cover of the second hydraulic cylinder through the oil circuit in the first piston rod (8); after the first piston rod (8) is fully extended, the E1 oil port is connected to the F1 oil port on the end cover of the first hydraulic cylinder (1); the F1 oil port is connected to the three-position four-way reversing valve (13) through the H1 oil port on the end cover of the first hydraulic cylinder (1); the H1 oil port is connected to the rod chamber of the first hydraulic cylinder (1).

2. A multi-cylinder sequential telescopic hydraulic system for a folding arm truck crane according to claim 1, characterized in that: Also includes a third hydraulic cylinder (3); The second hydraulic cylinder (2) is provided with a two-stage two-position two-way reversing valve (5), a second one-way valve (7) and a second central tube (12); The inlet end of the second one-way valve (7) is connected to the A2 oil port, and the other end is connected to the rodless chamber of the second hydraulic cylinder (2); The secondary two-position two-way reversing valve (5) is connected to both ends of the second one-way valve (7); One end of the second center tube (12) is fixedly connected to the bottom of the cylinder body of the second hydraulic cylinder (2), and the other end extends into the second center hole of the second piston rod (9) of the second hydraulic cylinder (2) and is slidably and sealingly connected to the second piston rod (9); The second center tube (12) is provided with a C2 oil port, the C2 oil port being connected to the D1 oil port via a B2 oil port at the bottom of the cylinder body of the second hydraulic cylinder (2); The second piston rod (9) is provided with a D2 oil port and an E2 oil port; The D2 oil port is adapted to the C2 oil port; the D2 oil port is connected to the A3 oil port at the bottom of the cylinder body of the third hydraulic cylinder through a pipeline; The E2 oil port is connected to the B3 oil port on the end cover of the third hydraulic cylinder (3) through the oil circuit in the second piston rod (9); after the second piston rod (9) is fully extended, the E2 oil port is connected to the F2 oil port on the end cover of the second hydraulic cylinder (2); the F2 oil port is connected to the E1 oil port through the H2 oil port on the end cover of the second hydraulic cylinder (2); the H2 oil port is connected to the rod chamber of the second hydraulic cylinder (2).

3. The multi-cylinder sequential telescopic hydraulic system of a folding arm truck crane according to claim 1, characterized in that: The first central tube (11) and the second central tube (12) are respectively hollow tubes with one end closed.

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