Hydraulic system and crane

Abstract

The invention provides a hydraulic system and a crane. The hydraulic system comprises a first limiting piece, a first pedal valve, a second limiting piece, a second pedal valve, a first valve set and a second valve set. The first valve group and the first pedal valve are adjusted, so that the first limiting piece relieves limiting of the main lifting hook of the crane, and the descending working condition of the main lifting hook is achieved; and the second valve group and the second pedal valve are adjusted, so that the second limiting piece relieves limiting of the auxiliary lifting hook of the crane, and the descending working condition of the auxiliary lifting hook is achieved. A first electric proportional valve is arranged, and the opening degree of the first electric proportional valve is adjusted by adjusting a first valve set and a first pedal valve, so that the dynamic compaction unhooking working condition of the main lifting hook is achieved; and a second electric proportional valve is arranged, and the opening degree of the second electric proportional valve is adjusted by adjusting a second valve group and a second pedal valve, so that the dynamic compaction unhooking working condition of the auxiliary lifting hook is achieved. The crane provided with the hydraulic system can be conveniently switched between two working conditions, so that the applicability of the crane is improved.

Description

Technical Field

[0001] The present application relates to the technical field of cranes, and in particular to a hydraulic system and a crane. Background Art

[0002] In the field of cranes, there are three types of free-fall hook reducer clutch control technologies for cranes: electric control single-chamber, hydraulic control single-chamber, and hydraulic control double-chamber. Among them, the hydraulic control method has a control performance advantage over the electric control method. Single-chamber control is mainly used for strong tamping and unhooking conditions, and double-chamber control is used for grab bucket lowering conditions. However, a crane cannot achieve the above two conditions, resulting in poor applicability of the crane. Summary of the invention

[0003] In view of this, the present application provides a hydraulic system to solve the problem of poor applicability of a crane equipped with the hydraulic system. The present application also provides a crane including the hydraulic system.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A hydraulic system, used in a crane, comprising:

[0006] A first limiter, a first pedal valve, a second limiter and a second pedal valve;

[0007] A first valve group is arranged in the hydraulic pipeline between the first limiter and the first pedal valve, and the first valve group includes a first electric proportional valve;

[0008] A second valve group is arranged in the hydraulic pipeline between the second limiter and the second pedal valve, and the second valve group includes a second electric proportional valve;

[0009] Among them, by adjusting the pedal angle of the first pedal valve, the first limiting member releases the limit on the first drum of the crane to realize the lowering condition of the main hook; by adjusting the pedal angle of the second pedal valve, the second limiting member releases the limit on the auxiliary second drum of the crane to realize the lowering condition of the auxiliary hook; by adjusting the opening of the first electric proportional valve, the strong compaction and unhooking condition of the main hook is realized; by adjusting the opening of the second electric proportional valve, the strong compaction and unhooking condition of the auxiliary hook is realized.

[0010] Optionally, the first limiting member is a first clutch, and the second limiting member is a second clutch.

[0011] Optionally, the first valve group includes:

[0012] a first switching valve, which is disposed in a hydraulic pipeline between the K chamber of the first clutch and the first pedal valve, and when the first switching valve is in a power-off state, the K chamber of the first clutch is connected to the output end of the first pedal valve; when the first switching valve is in a power-on state, the K chamber of the first clutch is connected to the oil tank of the hydraulic system;

[0013] The first switch valve is arranged in the hydraulic pipeline between the P chamber of the first clutch and the first pedal valve, and when the first switch valve is in a de-energized state, the P chamber of the first clutch is connected to the output end of the first pedal valve; when the first switch valve is in a energized state, the P chamber of the first clutch is connected to the input end of the first pedal valve.

[0014] Optionally, the second valve group includes:

[0015] a second switching valve, which is arranged in a hydraulic pipeline between the K chamber of the second clutch and the second pedal valve, and when the second switching valve is in a de-energized state, the K chamber of the second clutch is connected to the output end of the second pedal valve; when the second switching valve is in an energized state, the K chamber of the second clutch is connected to the oil tank of the hydraulic system;

[0016] The second switch valve is arranged in the hydraulic pipeline between the P chamber of the second clutch and the second pedal valve, and when the second switch valve is in a de-energized state, the P chamber of the second clutch is connected to the output end of the second pedal valve; when the second switch valve is in a energized state, the P chamber of the second clutch is connected to the input end of the second pedal valve.

[0017] Optionally, it also includes a connecting oil circuit arranged after the first switching valve and before the second switching valve.

[0018] Optional,

[0019] The first valve group includes a first safety valve, which is arranged in a hydraulic pipeline between the P chamber of the first clutch and the first electric proportional valve, and when the first safety valve is in a power-off state, the P chamber of the first clutch is connected to the oil tank; when the first safety valve is in a power-on state, the P chamber of the first clutch is connected to the first electric proportional valve;

[0020] The second valve group includes a second safety valve, which is arranged in the hydraulic pipeline between the P chamber of the second clutch and the second electric proportional valve. When the second safety valve is in a de-energized state, the P chamber of the second clutch is connected to the oil tank; when the second safety valve is in a energized state, the P chamber of the second clutch is connected to the second electric proportional valve.

[0021] Optional, including:

[0022] A controller, communicatively connected to the first electric proportional valve and / or the second electric proportional valve;

[0023] A position sensor is communicatively connected to the controller and is capable of detecting the position of the main hook and / or the auxiliary hook.

[0024] Optionally, also include:

[0025] a first valve pre-pressure sensor connected to an input end of the first pedal valve to detect a valve pre-pressure of the first pedal valve;

[0026] a first post-valve pressure sensor connected to the output end of the first pedal valve to detect a post-valve pressure of the first pedal valve;

[0027] The first enabling switch is connected to the first switch valve to adjust the state of the first switch valve, and when the pressure detected by the first post-valve pressure sensor reaches a first target value, the first enabling switch can adjust the state of the first switch valve.

[0028] Optionally, also include:

[0029] a second post-valve pressure sensor connected to the output end of the second pedal valve to detect the post-valve pressure of the second pedal valve;

[0030] The second enabling switch is connected to the second switch valve to adjust the state of the second switch valve, and when the pressure detected by the second post-valve pressure sensor reaches a second target value, the second enabling switch can adjust the state of the second switch valve.

[0031] A crane comprises any one of the hydraulic systems described above.

[0032] The hydraulic system provided by the present application adjusts the first valve group and the first pedal valve so that the first limiter releases the limit on the main hook of the crane to realize the lowering working condition of the main hook and realize the main hook drives the heavy object to move; adjusts the second valve group and the second pedal valve so that the second limiter releases the limit on the auxiliary hook of the crane to realize the lowering working condition of the auxiliary hook and realizes the auxiliary hook drives the heavy object to move. In addition, a first electric proportional valve is set, and the opening of the first electric proportional valve is adjusted by adjusting the first valve group and the first pedal valve to realize the strong tamping and unhooking working condition of the main hook; a second electric proportional valve is set, and the opening of the second electric proportional valve is adjusted by adjusting the second valve group and the second pedal valve to realize the strong tamping and unhooking working condition of the auxiliary hook. Such a setting can make a crane equipped with the above hydraulic system conveniently realize the switching of the two working conditions, that is, the crane can realize both the strong tamping and unhooking working condition and the grab bucket lowering working condition, thereby improving the applicability of the crane. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0034] Figure 1 A schematic diagram of the structure of the hydraulic system provided in this embodiment;

[0035] Figure 2 It is a side view of the crane;

[0036] Figure 3 is a schematic structural diagram of a first reel and a first clutch;

[0037] Figure 4 It is a schematic structural diagram of the second reel and the second clutch.

[0038] exist Figures 1 to 4 middle:

[0039] 1-first limiter, 2-first pedal valve, 3-second limiter, 4-second pedal valve, 5-first valve group, 6-second valve group, 7-connecting oil circuit, 8-first valve front pressure sensor, 9-first valve rear pressure sensor, 10-second valve rear pressure sensor, 11-first permission switch, 12-second permission switch, 13-oil pump, 14-overflow valve, 15-oil tank, 16-first drum, 17-second drum, 18-wire rope, 19-first clutch, 20-second clutch, 21-main hook;

[0040] 101-housing, 102-friction assembly, 103-spring, 104-transmission member, 501-first electric proportional valve, 502-first switching valve, 503-first switch valve, 504-first safety valve, 601-second electric proportional valve, 602-second switching valve, 603-second switch valve, 604-second safety valve. DETAILED DESCRIPTION

[0041] The present application provides a hydraulic system, which solves the problem of poor applicability of a crane provided with the hydraulic system. The present application also provides a crane including the hydraulic system.

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] like Figures 1 to 4 As shown, the embodiment of the present application provides a hydraulic system, which can be installed in engineering machinery, especially in cranes. The hydraulic system provides a power source for the engineering machinery, and then provides power for the operation of the engineering machinery. The hydraulic system is applied to the crane, and the hydraulic system mainly includes a first limiter 1, a first pedal valve 2, a second limiter 3, a second pedal valve 4, a first valve group 5 and a second valve group 6. The first limiter 1 limits the first drum 16 to limit the steel wire rope 18 wound on the first drum 16, and then limits the main hook 21 connected to the steel wire rope 18; correspondingly, the second limiter 3 limits the second drum 17 (not shown in the figure) to limit the steel wire rope 18 wound on the second drum 17, and then limits the auxiliary hook connected to the steel wire rope 18. Among them, the first pedal valve 2 can adjust the limiting force of the first limiting member 1 on the main hook 21 so that the main hook 21 can be lowered; the second pedal valve 4 can adjust the limiting force of the second limiting member 3 on the main hook 21 so that the auxiliary hook can be lowered.

[0044] Specifically, the first valve group 5 is arranged in the hydraulic pipeline between the first limiter 1 and the first pedal valve 2, and the first valve group 5 includes a first electric proportional valve 501, wherein the first valve group 5 can adjust the connection between the first limiter 1 and the first electric proportional valve 501, so that by adjusting the opening of the first electric proportional valve 501, the pressure of the hydraulic oil in the P chamber or the K chamber of the first limiter 1 can be adjusted to adjust the limiting force of the first limiter 1 on the main hook 21. The second valve group 6 is arranged in the hydraulic pipeline between the second limiter 3 and the second pedal valve 4, and the second valve group 6 includes a second electric proportional valve 601, wherein the second valve group 6 can adjust the connection between the second limiter 3 and the second electric proportional valve 601, so that by adjusting the opening of the second electric proportional valve 601, the pressure of the hydraulic oil in the P chamber or the K chamber of the second limiter 3 can be adjusted to adjust the limiting force of the second limiter 3 on the auxiliary hook.

[0045] Among them, when it is necessary to put the main hook 21 of the crane equipped with the hydraulic system into a hook lowering condition, the pedaling angle of the first pedal valve 2 is adjusted so that the first limit member 1 releases the limit on the main hook 21 of the crane to realize the lowering condition of the main hook 21; correspondingly, when it is necessary to put the auxiliary hook of the crane equipped with the hydraulic system into a hook lowering condition, the pedaling angle of the second pedal valve 4 is adjusted so that the second limit member 3 releases the limit on the auxiliary hook of the crane to realize the lowering condition of the auxiliary hook.

[0046] Furthermore, when it is necessary to put the main hook 21 of the crane equipped with the hydraulic system into a strong compaction and unhooking condition, the strong compaction and unhooking condition of the main hook 21 is realized by adjusting the opening of the first electric proportional valve 501. By setting the first electric proportional valve 501, the opening of the first electric proportional valve 501 can be conveniently and quickly adjusted, thereby preventing the steel wire rope 18 wound on the first drum 16 connected to the main hook 21 from being disrupted due to inertia after the heavy hammer connected to the main hook 21 falls to the ground, thereby achieving the purpose of emergency stop. When it is necessary to put the auxiliary hook of the crane equipped with the hydraulic system into a strong compaction and unhooking condition, the strong compaction and unhooking condition of the auxiliary hook is realized by adjusting the opening of the second electric proportional valve 601. By setting the second electric proportional valve 601, the opening of the second electric proportional valve 601 can be adjusted conveniently and quickly, thereby preventing the wire rope 18 on the second drum 17 connected to the auxiliary hook from being disrupted due to inertia after the heavy hammer connected to the auxiliary hook falls to the ground, thereby achieving the purpose of emergency stop.

[0047] It should be noted that the first pedal valve 2 and the second pedal valve 4 can be hydraulically controlled pedals or electrically controlled pedals.

[0048] The above-mentioned hydraulic system, by adjusting the first valve group 5 and the first pedal valve 2, allows the first limiter 1 to release the limit on the main hook 21 of the crane, so as to realize the lowering working condition of the main hook 21, and realize the main hook 21 drives the heavy object to move; by adjusting the second valve group 6 and the second pedal valve 4, allows the second limiter 3 to release the limit on the auxiliary hook of the crane, so as to realize the lowering working condition of the auxiliary hook, and realize the auxiliary hook drives the heavy object to move. In addition, a first electric proportional valve 501 is set, and the opening of the first electric proportional valve 501 is adjusted by adjusting the first valve group 5 and the first pedal valve 2 to realize the strong tamping and unhooking working condition of the main hook 21; a second electric proportional valve 601 is set, and the opening of the second electric proportional valve 601 is adjusted by adjusting the second valve group 6 and the second pedal valve 4 to realize the strong tamping and unhooking working condition of the auxiliary hook. Such an arrangement enables a crane equipped with the above hydraulic system to switch between two working conditions, that is, the crane can realize both the strong compaction unhooking condition and the grab lowering condition, thereby improving the applicability of the crane.

[0049] In some embodiments, the first stopper 1 is a first clutch 19, and the second stopper 3 is a second clutch 20. Specifically, the clutch includes a housing 101 and a friction assembly 102, a spring 103, a transmission member 104, a P cavity ( Figure 1 The P chamber) and the K chamber ( Figure 1 The spring 103 will apply elastic force to the friction assembly 102 through the transmission member 104 to make the dynamic friction plate and the static friction plate of the friction assembly 102 close to each other; however, when there is a pressure difference between the P chamber and the K chamber, if the pressure of the P chamber is greater than the pressure of the K chamber, a force will be applied to the transmission member 104 to move away from the friction assembly 102, and if the pressure of the K chamber is greater than the pressure of the P chamber, a force will be applied to the transmission member 104 to move closer to the friction assembly 102. The friction assembly 102 of the clutch is connected to a drum, and a steel wire rope 18 connected to the hook is wound on the drum. If the friction force of the friction assembly 102 is greater than the weight of the heavy object hoisted by the hook, the hook cannot be lowered. If the friction force of the friction assembly 102 is less than the weight of the heavy object hoisted by the hook, the hook can be lowered. Here, by setting the first limiter 1 and the second limiter 3 as clutches, adjusting the pressure of the P chamber or the K chamber through the hydraulic system, and adjusting the pressure difference between the P chamber and the K chamber, the friction between the friction components 102 can be adjusted, thereby achieving the hook lowering condition or the strong tamping unhooking condition. With such a setting, the control performance is excellent and the control is stable.

[0050] In some embodiments, the first valve group 5 includes a first switching valve 502 and a first switch valve 503. The first switching valve 502 is arranged in the hydraulic pipeline between the K chamber of the first clutch 19 and the first pedal valve 2, and when the first switching valve 502 is in the de-energized state, the K chamber of the first clutch 19 is connected to the output end of the first pedal valve 2; when the first switching valve 502 is in the energized state, the K chamber of the first clutch 19 is connected to the oil tank 15 of the hydraulic system. The first switch valve 503 is arranged in the hydraulic pipeline between the P chamber of the first clutch 19 and the first pedal valve 2, and when the first switch valve 503 is in the de-energized state, the P chamber of the first clutch 19 is connected to the output end of the first pedal valve 2; when the first switch valve 503 is in the energized state, the P chamber of the first clutch 19 is connected to the input end of the first pedal valve 2.

[0051] Specifically, when it is necessary to adjust the main hook 21 to the grab bucket lowering working condition, the first switching valve 502 and the first switch valve 503 are controlled to lose power, and the first electric proportional valve 501 is controlled to lose power, and the engine is ignited. At this time, the P chamber and the K chamber of the first clutch 19 are both connected to the output end of the first pedal valve 2. The operator steps on the first pedal valve 2 to a certain position and stops. At this time, the pressures in the P chamber and the K chamber of the first clutch 19 are the same; thereafter, the first switch valve 503 is controlled to be energized. At this time, the K chamber of the first clutch 19 is still connected to the output end of the first pedal valve 2, and the P chamber of the first clutch 19 is connected to the input end of the first pedal valve 2. Since there is a valve between the first pedal valve 2 and the fuel tank 15, The oil pump 13, that is, the P chamber of the first clutch 19 is the servo pressure established by the oil pump 13 and the overflow valve 14; thereafter, the operator slowly releases the first pedal valve 2, at which time the pressure in the K chamber of the first clutch 19 gradually decreases, which causes the pressure in the P chamber of the first clutch 19 to be greater than the pressure in the K chamber of the first clutch 19, so as to apply a force to the transmission member 104 away from the friction assembly 102, so as to reduce the pressure on the friction assembly 102, thereby reducing the friction between the friction assemblies 102; the operator continues to release the first pedal valve 2 until the friction between the friction assemblies 102 is less than the gravity of the weight hoisted by the main hook 21, so as to realize the lowering of the main hook 21.

[0052] Exemplarily, the first switching valve 502 may be a two-position three-way valve or a two-position four-way valve, and the first switch valve 503 may also be a two-position three-way valve or a two-position four-way valve.

[0053] It should be noted that the power source of the oil pump 13 and the relief valve 14 is not limited here, and other forms of power sources may also be used.

[0054] In some embodiments, the second valve group 6 includes a second switching valve 602 and a second switch valve 603. The second switching valve 602 is disposed in the hydraulic pipeline between the K chamber of the second clutch 20 and the second pedal valve 4, and when the second switching valve 602 is in the de-energized state, the K chamber of the second clutch 20 is connected to the output end of the second pedal valve 4; when the second switching valve 602 is in the energized state, the K chamber of the second clutch 20 is connected to the oil tank 15 of the hydraulic system. The second switch valve 603 is disposed in the hydraulic pipeline between the P chamber of the second clutch 20 and the second pedal valve 4, and when the second switch valve 603 is in the de-energized state, the P chamber of the second clutch 20 is connected to the output end of the second pedal valve 4; when the second switch valve 603 is in the energized state, the P chamber of the second clutch 20 is connected to the input end of the second pedal valve 4.

[0055] Specifically, when the auxiliary hook needs to be adjusted to the grab bucket lowering working condition, the second switching valve 602 and the second switch valve 603 are both de-energized, and the second electric proportional valve 601 is de-energized, and the engine is ignited. At this time, the P chamber and the K chamber of the second clutch 20 are both connected to the output end of the second pedal valve 4. The operator steps on the second pedal valve 4 to a certain position and stops. At this time, the pressures in the P chamber and the K chamber of the second clutch 20 are the same; thereafter, the second switch valve 603 is controlled to be energized. At this time, the K chamber of the second clutch 20 is still connected to the output end of the second pedal valve 4, and the P chamber of the second clutch 20 is connected to the input end of the second pedal valve 4. Since a valve is provided between the second pedal valve 4 and the fuel tank 15 There is an oil pump 13, that is to say, the P chamber of the second clutch 20 is the servo pressure established by the oil pump 13 and the relief valve 14; after that, the operator slowly releases the second pedal valve 4, at which time the pressure in the K chamber of the second clutch 20 gradually decreases, which causes the pressure in the P chamber of the second clutch 20 to be greater than the pressure in the K chamber of the second clutch 20, so as to apply a force to the transmission member 104 away from the friction assembly 102, so as to reduce the pressure on the friction assembly 102, thereby reducing the friction between the friction assemblies 102; the operator continues to release the second pedal valve 4 until the friction between the friction assemblies 102 is less than the gravity of the weight hoisted by the auxiliary hook, so as to realize the lowering of the auxiliary hook.

[0056] Exemplarily, the second switching valve 602 may be a two-position three-way valve or a two-position four-way valve, and the second switch valve 603 may also be a two-position three-way valve or a two-position four-way valve.

[0057] In some embodiments, the hydraulic system further includes a connecting oil circuit 7 provided between the first switching valve 502 and the second switching valve 602. Specifically, when the main hook 21 and the auxiliary hook are used to lift a heavy object together, the first switching valve 502 and the first switch valve 503 are controlled to lose power, the first electric proportional valve 501 and the second electric proportional valve 601 are controlled to lose power, and the second switching valve 602 is controlled to be energized. At this time, the P chamber and K chamber of the first clutch 19 and the K chamber of the second clutch 20 are all connected to the output end of the first pedal valve 2. The operator steps on the first pedal valve 2 to a certain position and stops. At this time, the pressures in the P chamber and K chamber of the first clutch 19 and the P chamber and K chamber of the second clutch 20 are the same; then, the first switch valve 503 and the second switch valve 603 are controlled to be energized, so that the P chamber of the first clutch 19 and the P chamber of the second clutch 20 are all connected to the input end of the first main pedal. Since an oil pump 13 and a relief valve 14 are provided between the first pedal valve 2 and the oil tank 15, that is to say, the P chamber of the first clutch 19 and the P chamber of the second clutch 20 are both the servo pressure established by the oil pump 13 and the relief valve 14, and the K chamber of the first clutch 19 and the K chamber of the second clutch 20 are both connected to the output end of the first pedal valve 2; then, the operator slowly releases the first pedal valve 2. At this time, the first clutch The pressures in the K chamber of the first clutch 19 and the K chamber of the second clutch 20 gradually decrease, which causes the pressure in the P chamber of the first clutch 19 to be greater than the pressure in the K chamber of the first clutch 19, and the pressure in the P chamber of the second clutch 20 to be greater than the pressure in the K chamber of the second clutch 20, so as to apply a force to the transmission member 104 of the first clutch 19 away from the friction assembly 102, and apply a force to the transmission member 104 of the second clutch 20 away from the friction assembly 102, thereby reducing the friction between the friction assemblies 102 of the first clutch 19, and reducing the friction between the friction assemblies 102 of the second clutch 20; thereafter, the operator continues to release the first pedal valve 2 until the sum of the friction between the friction assemblies 102 of the first clutch 19 and the friction between the friction assemblies 102 of the second clutch 20 is less than the gravity of the jointly hoisted weight, so as to realize the synchronous lowering of the main hook 21 and the auxiliary hook.

[0058] With such an arrangement, the main hook 21 and the auxiliary hook can be simultaneously lowered by controlling only the first pedal valve 2, so that when the main hook 21 and the auxiliary hook jointly lift a heavy object, the operator only needs to use one foot to control the pedal force of the first pedal valve 2 to achieve the simultaneous lowering of the main hook 21 and the auxiliary hook, thereby reducing the difficulty of lifting a heavy object with the main hook 21 and the auxiliary hook and reducing the labor intensity of the operator.

[0059] In addition, the connecting oil circuit 7 can also be set between the first switching valve 502 and the second switching valve 602, or the connecting oil circuit 7 can be set between the first switching valve 502 and the second switching valve 602 (not shown in the above two schemes), and an on-off valve can be set on the connecting oil circuit 7. In this way, when the main hook 21 and the auxiliary hook jointly lift a heavy object, the main hook 21 and the auxiliary hook can be controlled to be lowered synchronously by only controlling the first pedal valve 2.

[0060] In some embodiments, the first valve group 5 includes a first safety valve 504, which is arranged in the hydraulic pipeline between the P chamber of the first clutch 19 and the first electric proportional valve 501, and when the first safety valve 504 is in a de-energized state, the P chamber of the first clutch 19 is connected to the oil tank 15; when the first safety valve 504 is in a energized state, the P chamber of the first clutch 19 is connected to the first electric proportional valve 501.

[0061] Specifically, when it is necessary to control the main hook 21 to be in the strong tamping unhooking condition, the control template controls the first switching valve 502 and the first electric proportional valve 501 to be energized, and controls the first safety valve 504 to be de-energized. At this time, the opening of the first proportional valve is controlled by the first pedal valve 2. The engine is ignited, and the first pedal valve 2 is stepped on. At this time, the P chamber of the first clutch 19 is connected to the oil tank 15, and the K chamber of the first clutch 19 is also connected to the oil tank 15. At this time, the pressures of the P chamber and the K chamber of the first clutch 19 are equal and both are 0; then, the first switching valve 503 is energized. At this time, the pressure at the input port of the first electric proportional valve 501 is switched from the output pressure of the first pedal valve 2 to the servo pressure established by the oil pump 13 and the overflow valve 14; then, the first safety valve 504 is controlled to be energized. At this time, the first electric proportional valve 501 and the first The P chamber of a clutch 19 is turned on; then, slowly release the first pedal valve 2, the output pressure of the first pedal valve 2 becomes smaller and smaller, the current of the first electric proportional valve 501 gradually becomes smaller, the opening of the first electric proportional valve 501 gradually becomes larger, the output pressure of the first electric proportional valve 501 gradually becomes larger, the P chamber pressure of the first clutch 19 gradually becomes larger, and the friction force between the friction assembly 102 of the first clutch 19 becomes lower and lower, until the first clutch 19 is opened, thereby completing the strong tamping and unhooking of the main hook 21 and the heavy hammer.

[0062] Such an arrangement can conveniently realize the switching of the main hook 21 between the ramming and unhooking conditions, thereby improving the working efficiency of the ramming and unhooking.

[0063] In some embodiments, the second valve group 6 includes a second safety valve 604, which is arranged in the hydraulic pipeline between the P chamber of the second clutch 20 and the second electric proportional valve 601, and when the second safety valve 604 is in a de-energized state, the P chamber of the second clutch 20 is connected to the oil tank 15; when the second safety valve 604 is in a energized state, the P chamber of the second clutch 20 is connected to the second electric proportional valve 601.

[0064] Specifically, when it is necessary to control the auxiliary hook to be in the strong tamping and unhooking condition, the second switching valve 602 and the second electric proportional valve 601 are both energized, and the second safety valve 604 is de-energized. At this time, the opening of the second proportional valve is controlled by the second pedal valve 4. The engine is ignited, and the second pedal valve 4 is stepped on. At this time, the P chamber of the second clutch 20 is connected to the oil tank 15, and the K chamber of the second clutch 20 is also connected to the oil tank 15. At this time, the pressures of the P chamber and the K chamber of the second clutch 20 are equal and both are 0; then, the second switch valve 603 is energized, and at this time, the pressure of the input port of the second electric proportional valve 601 is switched from the output pressure of the second pedal valve 4 to the servo pressure established by the oil pump 13 and the overflow valve 14; then, the second safety valve 604 is controlled to be energized, and at this time, the second electric proportional valve 601 is connected to the P chamber of the second clutch 20; then, the second pedal valve 4 is slowly released, and the output pressure of the second pedal valve 4 becomes smaller and smaller, then the current of the second electric proportional valve 601 gradually becomes smaller, then the opening of the second electric proportional valve 601 gradually becomes larger, then the output pressure of the second electric proportional valve 601 gradually becomes larger, then the pressure of the P chamber of the second clutch 20 gradually becomes larger, until the second clutch 20 is opened, thereby completing the strong tamping and unhooking of the auxiliary hook and the heavy hammer.

[0065] In addition, it should be noted that the type of the solenoid valve is not limited herein, and the solenoid valve may also be a proportional valve.

[0066] In some embodiments, a controller and a position sensor are included. The controller (not shown in the figure) is connected to the first electric proportional valve 501 and / or the second electric proportional valve 601 in communication; the position sensor (not shown in the figure) is connected to the controller in communication, and can detect the position of the main hook 21 and / or the auxiliary hook. It should be noted that the main hook 21 and / or the auxiliary hook are connected to the load. Specifically, it can be seen from the contents of the above embodiments that when the main hook 21 and the load are uncoupled after strong compaction, the main hook 21 and the load will perform free fall together. The position of the weight is detected by setting a position sensor. When the load falls to the ground, if the drum with the wire rope 18 is not locked, the wire rope 18 on the drum will continue to slide due to inertia. The position of the load is detected by setting a position sensor. When the load falls to the ground, the position sensor transmits the detected position information to the controller. The controller sends a control signal to the first electric proportional valve 501, increases the current of the first electric proportional valve 501 to close the first electric proportional valve 501. At this time, the pressure of the P chamber of the first clutch 19 and the pressure of the K chamber of the first clutch 19 are both 0, so as to lock the drum to prevent the wire rope 18 on the drum from slipping due to inertia.

[0067] In addition, the method for controlling the tamping and unhooking of the auxiliary hook by the position sensor and the controller is similar to that described above and will not be repeated here.

[0068] In some embodiments, the hydraulic system also includes a first pre-valve pressure sensor 8, a first post-valve pressure sensor 9 and a first permission switch 11. The first pre-valve pressure sensor 8 is connected to the input end of the first pedal valve 2 to detect the pre-valve pressure of the first pedal valve 2; the first post-valve pressure sensor 9 is connected to the output end of the first pedal valve 2 to detect the post-valve pressure of the first pedal valve 2; the first permission switch 11 is connected to the first switch valve 503 to adjust the state of the first switch valve 503, and when the pressure detected by the first post-valve pressure sensor 9 reaches the first target value, the first permission switch 11 can adjust the state of the first switch valve 503.

[0069] Specifically, no matter the main hook 21 of the hydraulic system is in the hook lowering condition or the strong tamping unhooking condition, by setting the first valve rear pressure sensor 9 for detecting the output pressure of the first pedal valve 2, when the first valve rear pressure sensor 9 detects that the output pressure of the first pedal valve 2 reaches the target value, the operator presses the first permission switch 11 to switch the state of the first switch valve 503 to the energized state, so that the P chamber of the first clutch 19 is switched to the servo pressure established by the oil pump 13 and the relief valve 14; and when the pressure detected by the first valve rear pressure sensor 9 does not reach the target value, pressing the first switch permission switch cannot switch the state of the first switch valve 503. With such a setting, the switching of the state of the first switch valve 503 can be realized intelligently.

[0070] In some embodiments, the hydraulic system further includes a second post-valve pressure sensor 10 and a second permission switch 12. The second post-valve pressure sensor 10 is connected to the output end of the second pedal valve 4 to detect the post-valve pressure of the second pedal valve 4; the second permission switch 12 is connected to the second switch valve 603 to adjust the state of the second switch valve 603, and when the pressure detected by the second post-valve pressure sensor 10 reaches the second target value, the second permission switch 12 can adjust the state of the second switch valve 603.

[0071] Specifically, no matter the auxiliary hook of the hydraulic system is in the hook lowering condition or the strong tamping unhooking condition, by setting the second valve rear pressure sensor 10 for detecting the output pressure of the second pedal valve 4, when the second valve rear pressure sensor 10 detects that the output pressure of the second pedal valve 4 reaches the target value, the operator presses the second permission switch 12 to switch the state of the second switch valve 603 to the energized state, so that the P chamber of the second clutch 20 is switched to the servo pressure established by the oil pump 13 and the relief valve 14; and when the pressure detected by the second valve rear pressure sensor 10 does not reach the target value, pressing the second switch permission switch cannot switch the state of the second switch valve 603. With such a setting, the switching of the state of the second switch valve 603 can be realized intelligently.

[0072] It should be noted that the first valve pre-pressure sensor 8 is connected to the input end of the first pedal valve 2. Since the pressure at the input end of the second pedal valve 4 is the same as the input pressure of the first pedal valve 2, the first valve pre-pressure sensor 8 detects that the valve pre-pressure of the first pedal valve 2 is the same as the valve pre-pressure of the second pedal valve 4.

[0073] In some embodiments, the displacement angle of the first pedal valve 2 is positively correlated with the opening of the first electric proportional valve 501, that is, when the first pedal valve 2 is in the state of being stepped on to the bottom, the larger the lifting angle of the first pedal valve 2, the larger the opening angle of the first electric proportional valve 501; the displacement angle of the second pedal valve 4 is positively correlated with the opening of the second electric proportional valve 601, that is, when the second pedal valve 4 is in the state of being stepped on to the bottom, the larger the lifting angle of the second pedal valve 4, the larger the opening angle of the second electric proportional valve 601. With such a configuration, under the condition of strong tamping and uncoupling, the opening angle of the first electric proportional valve 501 can be controlled by controlling the lifting angle of the first pedal valve 2, and the opening angle of the second electric proportional valve 601 can be controlled by controlling the lifting angle of the second pedal valve 4, thereby improving the intelligent degree of system control.

[0074] A crane comprising any of the hydraulic systems described above. Since the crane comprises the hydraulic system described above, the beneficial effects of the crane brought by the hydraulic system can be found in the above content and will not be repeated here.

[0075] Exemplarily, the crane may be a tower crane, a bridge crane, a gantry crane, a mobile crane, a crawler crane, a mast crane, and the like.

[0076] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0077] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0078] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0079] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0080] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0081] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A hydraulic system, characterized in that: Used in cranes, including: A first limiter, a first pedal valve, a second limiter and a second pedal valve; A first valve group is arranged in the hydraulic pipeline between the first limiter and the first pedal valve, and the first valve group includes a first electric proportional valve; A second valve group is arranged in the hydraulic pipeline between the second limiter and the second pedal valve, and the second valve group includes a second electric proportional valve; Among them, by adjusting the pedal angle of the first pedal valve, the first limiting member releases the limit on the first drum of the crane to realize the lowering condition of the main hook; by adjusting the pedal angle of the second pedal valve, the second limiting member releases the limit on the second drum of the crane to realize the lowering condition of the auxiliary hook; by adjusting the opening of the first electric proportional valve, the strong compaction and unhooking condition of the main hook is realized; by adjusting the opening of the second electric proportional valve, the strong compaction and unhooking condition of the auxiliary hook is realized.

2. The hydraulic system according to claim 1, characterized in that: The first limiting member is a first clutch, and the second limiting member is a second clutch.

3. The hydraulic system according to claim 2, characterized in that: The first valve group comprises: a first switching valve, which is disposed in a hydraulic pipeline between the K chamber of the first clutch and the first pedal valve, and when the first switching valve is in a power-off state, the K chamber of the first clutch is connected to the output end of the first pedal valve; when the first switching valve is in a power-on state, the K chamber of the first clutch is connected to the oil tank of the hydraulic system; The first switch valve is arranged in the hydraulic pipeline between the P chamber of the first clutch and the first pedal valve, and when the first switch valve is in a de-energized state, the P chamber of the first clutch is connected to the output end of the first pedal valve; when the first switch valve is in a energized state, the P chamber of the first clutch is connected to the input end of the first pedal valve.

4. The hydraulic system according to claim 3, characterized in that: The second valve group comprises: a second switching valve, which is arranged in a hydraulic pipeline between the K chamber of the second clutch and the second pedal valve, and when the second switching valve is in a de-energized state, the K chamber of the second clutch is connected to the output end of the second pedal valve; when the second switching valve is in an energized state, the K chamber of the second clutch is connected to the oil tank of the hydraulic system; The second switch valve is arranged in the hydraulic pipeline between the P chamber of the second clutch and the second pedal valve, and when the second switch valve is in a de-energized state, the P chamber of the second clutch is connected to the output end of the second pedal valve; when the second switch valve is in a energized state, the P chamber of the second clutch is connected to the input end of the second pedal valve.

5. The hydraulic system according to claim 4, characterized in that: It also includes a connecting oil circuit arranged after the first switching valve and before the second switching valve.

6. The hydraulic system according to claim 4, characterized in that: The first valve group includes a first safety valve, which is arranged in a hydraulic pipeline between the P chamber of the first clutch and the first electric proportional valve, and when the first safety valve is in a power-off state, the P chamber of the first clutch is connected to the oil tank; when the first safety valve is in a power-on state, the P chamber of the first clutch is connected to the first electric proportional valve; The second valve group includes a second safety valve, which is arranged in the hydraulic pipeline between the P chamber of the second clutch and the second electric proportional valve. When the second safety valve is in a de-energized state, the P chamber of the second clutch is connected to the oil tank; when the second safety valve is in a energized state, the P chamber of the second clutch is connected to the second electric proportional valve.

7. The hydraulic system according to claim 1, characterized in that: include: A controller, communicatively connected to the first electric proportional valve and / or the second electric proportional valve; A position sensor is communicatively connected to the controller and is capable of detecting the position of the main hook and / or the auxiliary hook.

8. The hydraulic system according to claim 4, characterized in that: Also includes: a first valve pre-pressure sensor connected to an input end of the first pedal valve to detect a valve pre-pressure of the first pedal valve; a first post-valve pressure sensor connected to the output end of the first pedal valve to detect a post-valve pressure of the first pedal valve; The first enabling switch is connected to the first switch valve to adjust the state of the first switch valve, and when the pressure detected by the first post-valve pressure sensor reaches a first target value, the first enabling switch can adjust the state of the first switch valve.

9. The hydraulic system according to claim 8, characterized in that: Also includes: a second post-valve pressure sensor connected to the output end of the second pedal valve to detect the post-valve pressure of the second pedal valve; The second enabling switch is connected to the second switch valve to adjust the state of the second switch valve, and when the pressure detected by the second post-valve pressure sensor reaches a second target value, the second enabling switch can adjust the state of the second switch valve.

10. A crane, characterized in that: A hydraulic system comprising any one of claims 1-9.

Images