Telescopic arm hydraulic system and crawler crane

Abstract

The utility model discloses a telescopic boom hydraulic system and a crawler crane, and belongs to the technical field of telescopic boom crawler cranes. The hydraulic system includes a hydraulic oil tank, a hydraulic pump, a main reversing valve, a variable-length oil cylinder, a telescopic oil cylinder, a variable-length pilot proportional solenoid valve, and a telescopic pilot proportional solenoid valve; the oil inlet of the main reversing valve is connected to the oil outlet of the hydraulic pump; the A1 port of the main reversing valve is connected to the rodless cavity of the variable-length oil cylinder, and the B1 port of the main reversing valve is connected to the rod cavity of the variable-length oil cylinder; the A2 port of the main reversing valve is connected to the rodless cavity of the telescopic oil cylinder, and the B2 port of the main reversing valve is connected to the rod cavity of the telescopic oil cylinder; the variable-length pilot proportional solenoid valve is connected to the A1 port and the B1 port of the main reversing valve; and the telescopic pilot proportional solenoid valve is connected to the A2 port and the B2 port of the main reversing valve. The utility model can control the opening of the valve core of the main reversing valve in advance by arranging the variable-length pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve, thereby improving the control accuracy of the opening of the valve core of the main reversing valve.

Description

Technical Field

[0001] The utility model belongs to the field of telescopic arm crawler cranes, and in particular relates to a telescopic arm hydraulic system and a crawler crane. Background Art

[0002] Today's telescopic crawler cranes are equipped with a main boom luffing hydraulic system and a telescopic hydraulic system. The main oil circuits of the main boom luffing hydraulic system and the telescopic hydraulic system are controlled by the main reversing valve, and the reversing of the main reversing valve is controlled by controlling the opening of the handle to control the pilot control oil to act on the main valve core for reversing.

[0003] However, when operating the telescopic boom crawler crane to change the length and length, the manual control of the handle opening cannot accurately control the size of the main valve core opening, resulting in large impacts and vehicle shaking when the boom is raised and lowered at the maximum and minimum angles, and when the telescopic boom is extended and retracted at the longest and shortest arms. Although experienced operators will control the handle opening in advance, the control accuracy is inaccurate and the delay time is long, resulting in inaccurate control of the main valve core opening, and there is still a large impact. The impact and shaking that persist during long-term use will cause fatigue of the boom turntable structural parts, the boom cylinder and the telescopic cylinder, greatly shortening their service life, and even causing damage to the hydraulic cylinder seal, increasing the risk of oil leakage. Utility Model Content

[0004] The utility model aims to overcome the deficiencies in the prior art and to provide a telescopic arm hydraulic system and a crawler crane, which can control the opening of the main reversing valve core in advance when the telescopic arm is approaching the maximum and minimum angles and when the telescopic arm is approaching the longest and shortest angles, so as to avoid the whole vehicle from being shaken by a large impact and improve the opening control accuracy of the main reversing valve core.

[0005] In order to achieve the above purpose, the utility model is implemented by adopting the following technical solutions:

[0006] In the first aspect, a telescopic arm hydraulic system is provided, which includes a hydraulic oil tank and a hydraulic pump connected to the oil outlet of the hydraulic oil tank, and also includes a main reversing valve, a variable amplitude oil cylinder, a telescopic oil cylinder, a variable amplitude pilot proportional solenoid valve and a telescopic pilot proportional solenoid valve; the oil inlet of the main reversing valve is connected to the oil outlet of the hydraulic pump; the first variable amplitude oil outlet of the main reversing valve is connected to the rodless chamber of the variable amplitude oil cylinder, and the second variable amplitude oil outlet of the main reversing valve is connected to the rod chamber of the variable amplitude oil cylinder; the first telescopic oil outlet of the main reversing valve is connected to the rodless chamber of the telescopic cylinder, and the second telescopic oil outlet of the main reversing valve is connected to the rod chamber of the telescopic cylinder; the variable amplitude pilot proportional solenoid valve is connected to the first variable amplitude oil outlet and the second variable amplitude oil outlet of the main reversing valve; the telescopic pilot proportional solenoid valve is connected to the first telescopic oil outlet and the second telescopic oil outlet of the main reversing valve.

[0007] As an optional technical solution of the present invention, the variable amplitude pilot proportional solenoid valve includes a first variable amplitude pilot proportional solenoid valve and a second variable amplitude pilot proportional solenoid valve; the first variable amplitude pilot proportional solenoid valve is connected to the first variable amplitude oil outlet of the main reversing valve; the second variable amplitude pilot proportional solenoid valve is connected to the second variable amplitude oil outlet of the main reversing valve.

[0008] As an optional technical solution of the present invention, the telescopic pilot proportional solenoid valve includes a first telescopic pilot proportional solenoid valve and a second telescopic pilot proportional solenoid valve; the first telescopic pilot proportional solenoid valve is connected to the first telescopic oil outlet of the main reversing valve; the second telescopic pilot proportional solenoid valve is connected to the second telescopic oil outlet of the main reversing valve.

[0009] As an optional technical solution of the utility model, it also includes a safety overflow valve; the oil inlet of the safety overflow valve is connected to the main reversing valve, and the oil outlet is connected to the hydraulic oil tank.

[0010] As an optional technical solution of the utility model, it also includes a variable amplitude balancing valve; the variable amplitude balancing valve is arranged between the first variable amplitude oil outlet of the main reversing valve and the rodless chamber of the variable amplitude oil cylinder.

[0011] As an optional technical solution of the utility model, it also includes a first pressure sensor and a second pressure sensor; the first pressure sensor is connected to the rod chamber of the variable-length oil cylinder; the second pressure sensor is connected to the rodless chamber of the variable-length oil cylinder.

[0012] As an optional technical solution of the utility model, it also includes a telescopic switching valve and a telescopic balancing valve; the telescopic switching valve and the telescopic balancing valve are sequentially arranged between the first telescopic oil outlet of the main reversing valve and the rodless chamber of the telescopic oil cylinder.

[0013] As an optional technical solution of the utility model, it also includes a length sensor and an angle sensor; the length sensor is connected to the telescopic cylinder; the angle sensor is connected to the amplitude-changing cylinder.

[0014] As an optional technical solution of the utility model, it also includes a controller; the controller is connected to the length sensor, angle sensor, variable amplitude pilot proportional solenoid valve and telescopic pilot proportional solenoid valve, and is used to receive signals from the length sensor and angle sensor, and adjust the valve core opening of the main reversing valve by controlling the variable amplitude pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve.

[0015] In a second aspect, a crawler crane is provided, characterized in that it comprises a telescopic arm and the telescopic arm hydraulic system described in the first aspect; the boom cylinder and the telescopic cylinder are transmission-connected to the telescopic arm.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] (1) The telescopic arm hydraulic system provided by the utility model controls the opening of the main reversing valve core in advance when the telescopic arm is about to reach the maximum and minimum angles and when the telescopic arm is about to reach the longest and shortest angles by setting the luffing pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve, so as to avoid the whole vehicle from being shaken by a large impact, improve the control accuracy of the main reversing valve core opening, increase the service life of other structural parts, luffing cylinder and telescopic cylinder, and reduce the risk of damage and oil leakage of the luffing cylinder and telescopic cylinder.

[0018] (2) The crawler crane provided by the utility model can more accurately control the luffing and extension of the telescopic arm through the setting of the telescopic arm hydraulic system, avoid large shaking during the luffing and extension, and improve the service life of the crawler crane. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the telescopic arm hydraulic system in the embodiment of the utility model.

[0020] Marked in the figure are: 1. Hydraulic oil tank; 2. Hydraulic pump; 3. Safety overflow valve; 4. Main reversing valve; 5. Variable amplitude balancing valve; 6. Variable amplitude cylinder; 7. Telescopic switching valve; 8. Telescopic balancing valve; 9. Telescopic cylinder; 10. First pressure sensor; 11. Second pressure sensor; 12. Angle sensor; 13. Length sensor; 14. First variable amplitude pilot proportional solenoid valve; 15. Second variable amplitude pilot proportional solenoid valve; 16. First telescopic pilot proportional solenoid valve; 17. Second telescopic pilot proportional solenoid valve. DETAILED DESCRIPTION

[0021] The utility model is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model.

[0022] Example 1

[0023] This embodiment provides a telescopic arm hydraulic system, such as Figure 1 As shown, it includes a hydraulic oil tank 1, a hydraulic pump 2 connected to the oil outlet of the hydraulic oil tank 1, a safety relief valve 3, a main reversing valve 4, a variable amplitude balance valve 5, a variable amplitude cylinder 6, a telescopic switching valve 7, a telescopic balance valve 8, a telescopic cylinder 9, a first pressure sensor 10, a second pressure sensor 11, an angle sensor 12, a length sensor 13, a variable amplitude pilot proportional solenoid valve and a telescopic pilot proportional solenoid valve. The variable amplitude pilot proportional solenoid valve includes a first variable amplitude pilot proportional solenoid valve 14 and a second variable amplitude pilot proportional solenoid valve 15. The telescopic pilot proportional solenoid valve includes a first telescopic pilot proportional solenoid valve 16 and a second telescopic pilot proportional solenoid valve 17.

[0024] Further, the oil inlet of the main reversing valve 4 is connected to the oil outlet of the hydraulic pump 2. The A1 port (first amplitude-changing oil outlet) of the main reversing valve 4 is connected to the rodless chamber of the amplitude-changing oil cylinder 6, and the B1 port (second amplitude-changing oil outlet) of the main reversing valve 4 is connected to the rod chamber of the amplitude-changing oil cylinder 6. The A2 port (first telescopic oil outlet) of the main reversing valve 4 is connected to the rodless chamber of the telescopic oil cylinder 9, and the B2 port (second telescopic oil outlet) of the main reversing valve 4 is connected to the rod chamber of the telescopic oil cylinder 9. The amplitude-changing pilot proportional solenoid valve is connected to the A1 port and the B1 port of the main reversing valve 4. The telescopic pilot proportional solenoid valve is connected to the A2 port and the B2 port of the main reversing valve 4.

[0025] Furthermore, when the driver does not operate the handle, the valve core of the main reversing valve 4 is in a neutral position under the action of the return springs at both ends.

[0026] Furthermore, the A1 port, the B1 port, the A2 port and the B2 port of the main reversing valve 4 are all oil outlets.

[0027] Further, the first variable amplitude pilot proportional solenoid valve 14 is connected to the A1 port of the main reversing valve 4. The second variable amplitude pilot proportional solenoid valve 15 is connected to the B1 port of the main reversing valve 4. When the first variable amplitude pilot proportional solenoid valve 14 is energized, the A1 port of the main reversing valve 4 discharges oil; when the second variable amplitude pilot proportional solenoid valve 15 is energized, the B1 port of the main reversing valve 4 discharges oil.

[0028] Furthermore, the first telescopic pilot proportional solenoid valve 16 is connected to the A2 port of the main reversing valve 4; the second telescopic pilot proportional solenoid valve 17 is connected to the B2 port of the main reversing valve 4. When the first telescopic pilot proportional solenoid valve 16 is energized, the A2 port of the main reversing valve 4 discharges oil; when the second telescopic pilot proportional solenoid valve 17 is energized, the B2 port of the main reversing valve 4 discharges oil.

[0029] Furthermore, the oil inlet of the safety relief valve 3 is connected to the main reversing valve 4, and the oil outlet is connected to the hydraulic oil tank 1, so as to prevent the main reversing valve 4 from overflowing. The hydraulic pump 2 normally outputs high-pressure oil to the main reversing valve 4, and when the high-pressure oil in the main reversing valve 4 reaches the set value of the safety relief valve 3, it overflows back to the hydraulic oil tank 1.

[0030] Furthermore, the luffing balancing valve 5 is disposed between the A1 port of the main reversing valve 4 and the rodless chamber of the luffing oil cylinder 6 to balance the pressure in the hydraulic system.

[0031] Further, the first pressure sensor 10 is connected to the rod chamber of the luffing cylinder 6. The second pressure sensor 11 is connected to the rodless chamber of the luffing cylinder 6. The first pressure sensor 10 and the second pressure sensor 11 are used to detect the pressure in the rod chamber and the rodless chamber of the luffing cylinder 6, respectively.

[0032] Furthermore, the telescopic switching valve 7 and the telescopic balancing valve 8 are sequentially arranged between the A2 port of the main reversing valve 4 and the rodless chamber of the telescopic oil cylinder 9. The telescopic switching valve 7 is used for the hydraulic system to switch the extension or shortening state of the telescopic arm. The telescopic balancing valve 8 is used to balance the pressure in the hydraulic system.

[0033] Furthermore, the length sensor 13 is connected to the telescopic cylinder 9, and is used to detect the maximum and shortest lengths of the telescopic boom through the length sensor 13 in advance when the telescopic arm is extended or retracted. The angle sensor 12 is connected to the luffing cylinder 6, and is used to detect the maximum and minimum angles of the telescopic boom with the ground plane through the angle sensor 12 in advance when the telescopic arm is luffed or raised.

[0034] This embodiment also includes a controller. The controller is connected to the length sensor 13, the angle sensor 12, the amplitude-changing pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve, and is used to receive signals from the length sensor 13 and the angle sensor 12, and adjust the valve core opening of the main reversing valve 4 by controlling the amplitude-changing pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve. In this way, the amplitude change and telescopic movement of the telescopic arm can be carried out slowly when the amplitude change and telescopic movement are about to reach the maximum and minimum extents, so as to reduce the impact and shaking.

[0035] Example 2

[0036] This embodiment provides a control process of the telescopic arm hydraulic system described in Embodiment 1. The control process is divided into controlling the telescopic arm to fall and rise, and controlling the telescopic arm to shorten and lengthen.

[0037] Control the telescopic boom to fall: The driver operates the handle to change the boom and the boom falls. The pilot control oil first passes through the operating handle to the second boom-changing pilot proportional solenoid valve 15, and then enters the boom-changing link of the main reversing valve 4 and acts on the left end of the valve core of the main reversing valve 4. At this time, the main valve reversing valve 4 is in the left position. High-pressure oil enters the rod chamber of the boom-changing oil cylinder 6 from port B1, and the telescopic boom begins to fall. When the angle sensor 12 detects that the angle between the telescopic boom and the ground is about to reach the minimum value, it is fed back to the controller. The controller outputs current to control the second boom-changing pilot proportional solenoid valve 15, so that the opening of the valve core of the main reversing valve 4 becomes smaller, and the boom slowly falls and retracts.

[0038] Control the telescopic boom to rise: The driver operates the handle to raise the boom, and the pilot control oil first passes through the operating handle to the first boom-changing pilot proportional solenoid valve 14, and then enters the boom-changing link of the main reversing valve 4 and acts on the right end of the valve core of the main reversing valve 4. At this time, the main valve reversing valve 4 is in the right position. High-pressure oil enters the rodless chamber of the boom-changing oil cylinder 6 from the A1 port, and the telescopic boom begins to rise. When the angle sensor 12 detects that the angle between the telescopic boom and the ground is about to reach the maximum value, it is fed back to the controller. The controller outputs current to control the first boom-changing pilot proportional solenoid valve 14, so that the opening of the valve core of the main reversing valve 4 becomes smaller, and the boom rises slowly.

[0039] Control the telescopic arm to shorten: The driver operates the telescopic arm with the operating handle, and the pilot control oil first passes through the operating handle to the second telescopic pilot proportional solenoid valve 17, and then enters the telescopic joint of the main reversing valve 4 and acts on the left end of the valve core of the main reversing valve 4. At this time, the main valve reversing valve 4 is in the left position. High-pressure oil enters the rod chamber of the telescopic oil cylinder 9 from the B2 port, and the telescopic arm begins to shorten. When the length sensor 13 detects that the telescopic arm is about to shorten to the minimum value, it is fed back to the controller. The controller outputs current to control the second telescopic pilot proportional solenoid valve 17, so that the valve core opening of the main reversing valve 4 becomes smaller, and the arm slowly shortens.

[0040] Control the extension of the telescopic arm: The driver operates the telescopic arm with the operating handle, and the pilot control oil first passes through the operating handle to the first telescopic pilot proportional solenoid valve 16, and then enters the telescopic joint of the main reversing valve 4 and acts on the right end of the valve core of the main reversing valve 4. At this time, the main valve reversing valve 4 is in the right position. High-pressure oil enters the rodless chamber of the telescopic oil cylinder 9 from the A2 port, and the telescopic arm begins to extend. When the length sensor 13 detects that the telescopic arm is about to extend to the maximum value, it is fed back to the controller. The controller outputs current to control the first telescopic pilot proportional solenoid valve 16, so that the valve core opening of the main reversing valve 4 becomes smaller, and the arm slowly extends.

[0041] Example 3

[0042] This embodiment provides a crawler crane, comprising a telescopic arm and the telescopic arm hydraulic system described in Embodiment 1. The luffing cylinder 6 and the telescopic cylinder 9 are transmission-connected to the telescopic arm.

[0043] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 the present invention can be understood by specific circumstances.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A telescopic arm hydraulic system, comprising a hydraulic oil tank (1) and a hydraulic pump (2) connected to an oil outlet of the hydraulic oil tank (1), characterized in that: It also includes a main reversing valve (4), a variable amplitude oil cylinder (6), a telescopic oil cylinder (9), a variable amplitude pilot proportional solenoid valve and a telescopic pilot proportional solenoid valve; The oil inlet of the main reversing valve (4) is connected to the oil outlet of the hydraulic pump (2); the first amplitude-changing oil outlet of the main reversing valve (4) is connected to the rodless chamber of the amplitude-changing oil cylinder (6), and the second amplitude-changing oil outlet of the main reversing valve (4) is connected to the rod-carrying chamber of the amplitude-changing oil cylinder (6); the first telescopic oil outlet of the main reversing valve (4) is connected to the rodless chamber of the telescopic oil cylinder (9), and the second telescopic oil outlet of the main reversing valve (4) is connected to the rod-carrying chamber of the telescopic oil cylinder (9); The variable amplitude pilot proportional solenoid valve is connected to the first variable amplitude oil outlet and the second variable amplitude oil outlet of the main reversing valve (4); The telescopic pilot proportional solenoid valve is connected to a first telescopic oil outlet and a second telescopic oil outlet of the main reversing valve (4).

2. The telescopic arm hydraulic system according to claim 1, characterized in that: The variable amplitude pilot proportional solenoid valve comprises a first variable amplitude pilot proportional solenoid valve (14) and a second variable amplitude pilot proportional solenoid valve (15); The first variable amplitude pilot proportional solenoid valve (14) is connected to the first variable amplitude oil outlet of the main reversing valve (4); The second variable amplitude pilot proportional solenoid valve (15) is connected to the second variable amplitude oil outlet of the main reversing valve (4).

3. The telescopic arm hydraulic system according to claim 1, characterized in that: The telescopic pilot proportional solenoid valve comprises a first telescopic pilot proportional solenoid valve (16) and a second telescopic pilot proportional solenoid valve (17); The first telescopic pilot proportional solenoid valve (16) is connected to the first telescopic oil outlet of the main reversing valve (4); The second telescopic pilot proportional solenoid valve (17) is connected to the second telescopic oil outlet of the main reversing valve (4).

4. The telescopic arm hydraulic system according to claim 1, characterized in that: Also includes a safety relief valve (3); The oil inlet of the safety relief valve (3) is connected to the main reversing valve (4), and the oil outlet is connected to the hydraulic oil tank (1).

5. The telescopic arm hydraulic system according to claim 1, characterized in that: It also comprises a variable amplitude balancing valve (5); the variable amplitude balancing valve (5) is arranged between the first variable amplitude oil outlet of the main reversing valve (4) and the rodless chamber of the variable amplitude oil cylinder (6).

6. The telescopic arm hydraulic system according to claim 1, characterized in that: Also includes a first pressure sensor (10) and a second pressure sensor (11); The first pressure sensor (10) is connected to the rod chamber of the luffing oil cylinder (6); The second pressure sensor (11) is connected to the rodless chamber of the luffing oil cylinder (6).

7. The telescopic arm hydraulic system according to claim 1, characterized in that: It also includes a telescopic switching valve (7) and a telescopic balancing valve (8); The telescopic switching valve (7) and the telescopic balancing valve (8) are arranged in sequence between the first telescopic oil outlet of the main reversing valve (4) and the rodless chamber of the telescopic oil cylinder (9).

8. The telescopic arm hydraulic system according to claim 1, characterized in that: Also includes a length sensor (13) and an angle sensor (12); The length sensor (13) is connected to the telescopic cylinder (9); The angle sensor (12) is connected to the amplitude-changing oil cylinder (6).

9. The telescopic arm hydraulic system according to claim 8, characterized in that: Also includes a controller; The controller is connected to the length sensor (13), the angle sensor (12), the variable amplitude pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve, and is used to receive signals from the length sensor (13) and the angle sensor (12), and to adjust the valve core opening of the main reversing valve (4) by controlling the variable amplitude pilot proportional solenoid valve and the telescopic pilot proportional solenoid valve.

10. A crawler crane, characterized in that: A telescopic arm and a telescopic arm hydraulic system according to any one of claims 1 to 9; The amplitude-changing oil cylinder (6) and the telescopic oil cylinder (9) are transmission-connected to the telescopic arm.

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