CN116591256A - Boom hydraulic system and excavator - Google Patents

Abstract

The embodiment of the invention discloses a movable arm hydraulic system and an excavator. The movable arm hydraulic system comprises two explosion-proof valves, two oil cylinders, an oil delivery module, a pressure compensation acquisition module, a hydraulic control module, an oil delivery control module and a controller; the rodless cavity of each oil cylinder is communicated with the oil outlet of one explosion-proof valve, the oil inlet of each explosion-proof valve is communicated with a first oil conveying path port of the oil conveying module, the rod cavities of the two oil cylinders and the oil return port of the explosion-proof valve are communicated with a second oil conveying path port of the oil conveying module, and the oil conveying control module is communicated with the oil conveying module; the hydraulic control module is communicated with the control port of the explosion-proof valve, the pressure detection ports of the two explosion-proof valves are communicated through the pressure compensation acquisition module, and the oil transportation module, the pressure compensation acquisition module and the hydraulic control module are all connected with the controller. According to the scheme, unbalanced load of the two oil cylinders for controlling the movable arm can be avoided, the movable arm can be locked at the fixed position in time when the operation of the movable arm fails, and the operation stability and safety of the movable arm hydraulic system are improved.

Description

Boom hydraulic system and excavator

Technical Field

The embodiment of the invention relates to the technical field of excavators, in particular to a movable arm hydraulic system and an excavator.

Background

In the prior art, when the hydraulic system of the explosion-proof valve is used for simultaneously acting the pilot oil output by the pilot pump on the control end of the on-off valve of the explosion-proof valve and the descending control end of the movable arm linkage valve core of the main valve, the on-off valve needs to be opened when the movable arm is controlled to descend, namely, the oil in the rodless cavity is returned through the on-off valve when the movable arm descends. However, the pilot pressure P1 for moving the main valve boom spool is not always equal to the unlock pressure P2 of the on-off valve in the explosion-proof valve. The on-off valve in the explosion-proof valve is assumed to have a release lock pressure P2 greater than a pilot pressure P1 for moving the main valve boom linkage valve element. When the pilot pressure reaches the pilot pressure P1 for moving the main valve movable arm linkage valve core, the main valve movable arm linkage valve core starts to move at the moment, high-pressure oil of the main pump enters a rod cavity of the movable arm oil cylinder, but at the moment, the pilot pressure is smaller than the unlocking locking pressure P2 of the on-off valve in the explosion-proof valve, so that the on-off valve of the explosion-proof valve cannot be opened, and obviously, the rodless cavity of the movable arm oil cylinder cannot return oil, so that the pressure in the rodless cavity of the oil cylinder is increased; when the pilot pressure is raised to the unlocking pressure P2 of the on-off valve in the explosion-proof valve, the on-off valve of the explosion-proof valve is opened, so that the high-pressure oil in the rodless cavity returns through the on-off valve of the explosion-proof valve, and the pressure in the rodless cavity of the oil cylinder is reduced.

Obviously, in the process that the pilot pressure gradually rises from the pilot pressure P1 for moving the main valve movable arm linkage valve core to the unlocking pressure P2 of the on-off valve in the explosion-proof valve, certain pressure fluctuation is generated in the oil cylinder, and the oil cylinder is subjected to leakage faults due to the pressure fluctuation and the impact, so that the reliability of the hydraulic system of the explosion-proof valve is reduced.

Disclosure of Invention

The embodiment of the invention provides a movable arm hydraulic system and an excavator, which are used for improving the reliability of the movable arm hydraulic system.

In a first aspect, an embodiment of the present invention provides a boom hydraulic system, including two explosion-proof valves, two cylinders, an oil delivery module, a pressure compensation acquisition module, a hydraulic control module, an oil delivery control module, and a controller;

the rodless cavity of each oil cylinder is communicated with an oil outlet of one explosion-proof valve, an oil inlet of each explosion-proof valve is communicated with a first oil conveying path port of the oil conveying module, the rod cavities of the two oil cylinders and an oil return port of the explosion-proof valve are both communicated with a second oil conveying path port of the oil conveying module, the oil conveying control module is communicated with the oil conveying module, and the oil conveying control module is used for controlling the oil conveying module to conduct oil conveying of the first oil conveying path port or the second oil conveying path port; the hydraulic control module is communicated with the control port of the explosion-proof valve and is used for adjusting the pressure of the control port of the explosion-proof valve; the pressure detection ports of the two explosion-proof valves are communicated through the pressure compensation acquisition module, and the pressure compensation acquisition module is used for balancing the hydraulic pressures of the two explosion-proof valves and detecting the hydraulic pressure of the explosion-proof valves; the oil transportation module, the pressure compensation acquisition module and the hydraulic control module are all connected with the controller, and the controller is used for controlling the oil transportation amount of the oil transportation module or controlling the hydraulic control module to adjust the pressure of a control port of the explosion-proof valve according to the hydraulic pressure of the explosion-proof valve.

Optionally, the pressure compensation acquisition module comprises a pressure sensor and a pressure compensation hydraulic pipe;

the pressure detection ports of the two explosion-proof valves are communicated through the pressure compensation hydraulic pipe, and the pressure compensation hydraulic pipe is used for balancing the hydraulic pressures of the two explosion-proof valves;

the pressure sensor is connected with the pressure detection port, and the pressure detection port is used for detecting the hydraulic pressure of the explosion-proof valve.

Optionally, the oil delivery module comprises a movable arm linkage reversing valve and a main pump;

the main pump is connected with an oil inlet of the movable arm linkage reversing valve, a first oil port of the movable arm linkage reversing valve is used as the first oil transportation path port, and a second oil port of the movable arm linkage reversing valve is used as the second oil transportation path port;

the oil transportation control module is communicated with a pilot port of the movable arm linkage reversing valve and is used for controlling the hydraulic pressure of the pilot port of the movable arm linkage reversing valve so as to control the first oil port or the second oil port of the movable arm linkage reversing valve to be communicated;

the controller is connected with the main pump and is used for controlling the oil delivery amount of the main pump according to the hydraulic pressure of the explosion-proof valve.

Optionally, the oil transportation control module comprises a proportional reversing valve and a proportional valve;

the movable arm linkage reversing valve further comprises a first guide port and a second guide port;

the first conveying port of the proportional reversing valve is communicated with the first pilot port, the second conveying port of the proportional reversing valve is communicated with the second pilot port, the proportional valve is communicated with the proportional reversing valve, and the proportional valve is used for adjusting the proportional reversing valve to convey pilot oil to the first pilot port or the second pilot port so as to adjust the hydraulic pressure of the first pilot port or the second pilot port.

Optionally, the hydraulic control module comprises a proportional pressure reducing valve and an electromagnetic switch valve;

the proportional pressure reducing valve is communicated with the electromagnetic switch valves, the electromagnetic switch valves are communicated with the control ports of each explosion-proof valve, the proportional pressure reducing valve and the electromagnetic switch valves are connected with the controller, the controller is used for controlling the hydraulic pressure of pilot oil which is delivered to the electromagnetic switch valves by the proportional pressure reducing valves, and the controller is used for controlling the hydraulic pressure of the pilot oil which is delivered to the control ports by the electromagnetic switch valves.

Optionally, the boom hydraulic system further comprises a pilot pump;

the hydraulic control module and the oil delivery control module are communicated with the pilot pump, and the pilot pump is used for delivering pilot oil to the hydraulic control module or the oil delivery control module.

Optionally, the boom hydraulic system further comprises a pilot filter;

the pilot filter is connected with the pilot pump, the hydraulic control module and the oil delivery control module are both connected with the pilot filter, and the pilot filter is used for filtering the pilot oil.

Optionally, the boom hydraulic system further comprises a tank;

each explosion-proof valve, the oil delivery module, the hydraulic control module and the oil delivery control module are all connected with the oil tank, the oil tank is used for supplying oil to the oil delivery module, the hydraulic control module and the oil delivery control module, and the oil tank is also used for receiving backflow oil of the explosion-proof valve, the oil delivery module, the hydraulic control module and the oil delivery control module.

Optionally, the boom hydraulic system further comprises a check valve;

the main pump is communicated with the movable arm linkage reversing valve through the one-way valve, and the one-way valve is used for controlling the oil conveying direction of the main pump and the movable arm linkage reversing valve.

In a second aspect, the embodiment of the invention also provides an excavator, which comprises the movable arm hydraulic system provided by the embodiment of the invention.

According to the movable arm hydraulic system provided by the embodiment of the invention, the oil conveying module can be controlled to conduct different oil conveying path ports to convey oil to the rod cavity of the oil cylinder or the rodless cavity of the oil cylinder through the oil conveying control module, so that the lifting control of the oil cylinder on the movable arm is realized. The pressure compensation acquisition module not only can balance the hydraulic pressure of the two explosion-proof valves to eliminate the phenomenon that the two oil cylinders control the movable arm to have unbalanced load due to the flow difference, but also can detect the hydraulic pressure of the explosion-proof valves in real time and feed the hydraulic pressure back to the controller in time, so that the controller can adjust the operation of the movable arm hydraulic system in real time according to the hydraulic pressure of the explosion-proof valves, and the operation stability of the movable arm hydraulic system is improved. The hydraulic control module can reduce the pressure fluctuation of the oil cylinder and the pressure impact received by the oil cylinder under the control of the controller, so that the leakage failure rate of the oil cylinder is reduced, and the running stability of the movable arm hydraulic system is further improved. In addition, the movable arm hydraulic system formed by the two explosion-proof valves, the two oil cylinders, the oil delivery module, the pressure compensation acquisition module, the hydraulic control module, the oil delivery control module and the controller can lock the movable arm at a fixed position in time under the conditions of overload of the movable arm, burst of an ascending oil inlet pipeline of the movable arm, burst of a descending oil return pipeline of the movable arm and the like, so that the safety of the movable arm hydraulic system is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of an explosion-proof valve according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a boom hydraulic system according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a hydraulic system for a boom according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In order to better explain the scheme of the invention, the structure of the existing explosion-proof valve is briefly described first.

Fig. 1 is a schematic structural diagram of an explosion-proof valve according to an embodiment of the present invention, where, as shown in fig. 1, the explosion-proof valve includes a check valve 111, an on-off valve 112, a pressure detection port E, an overload overflow valve 113, an oil outlet C, an oil inlet a, and an oil return port R. And an oil drain port D and a control port P.

The oil inlet a is in single-phase communication with the oil outlet C through the check valve 111, that is, high-pressure oil flowing in the oil inlet a can be conveyed to the oil outlet C, but high-pressure oil of the oil outlet C cannot be conveyed to the oil inlet a. The oil outlet C is communicated with the oil return port R and the oil inlet A through the on-off valve 112, when the hydraulic pressure of the control port P reaches a certain pressure value, the on-off valve 112 is conducted, and high-pressure oil of the oil outlet C can flow back into the oil return port R or the oil inlet A through the on-off valve 112; when the hydraulic pressure of the control port P does not reach a certain pressure value, the on-off valve 112 is turned off, and high-pressure oil of the oil outlet C cannot flow back to the oil return port R or the oil inlet A through the on-off valve 112. The oil outlet C is also communicated with the oil return port R and the oil inlet A through the overload overflow valve 113, and when the overload overflow valve 113 is conducted, the oil of the oil outlet C can flow back to the oil return port R or the oil inlet A through the overload overflow valve 113; when the overload relief valve 113 is closed, high-pressure oil of the oil outlet C cannot flow back into the oil return port R or the oil inlet a through the overload relief valve 113. When the explosion-proof valve needs to be overhauled, high-pressure oil in the explosion-proof valve can be discharged through the oil drain port D.

The embodiment of the invention provides a movable arm hydraulic system, which comprises two explosion-proof valves with the structure, the specific structure of the explosion-proof valves is not repeated in the following embodiment, and the structure and the working principle of the movable arm hydraulic system are described in detail below.

Fig. 2 is a schematic structural diagram of a boom hydraulic system according to an embodiment of the present invention, as shown in fig. 2, the boom hydraulic system includes two explosion-proof valves 110, two cylinders 120, an oil delivery module 130, a pressure compensation acquisition module 140, a hydraulic control module 150, an oil delivery control module 160, and a controller 170;

the rodless cavity of each oil cylinder 120 is communicated with an oil outlet C of one explosion-proof valve 110, an oil inlet A of each explosion-proof valve 110 is communicated with a first oil delivery path port of the oil delivery module 130, the rod cavities of the two oil cylinders 120 and an oil return port R of the explosion-proof valve 110 are both communicated with a second oil delivery path port of the oil delivery module 130, an oil delivery control module 160 is communicated with the oil delivery module 130, and the oil delivery control module 160 is used for controlling the oil delivery module 130 to conduct the first oil delivery path port or the second oil delivery path port for oil delivery; the hydraulic control module 150 is connected with the control port P of the explosion-proof valve 110, and the hydraulic control module 150 is used for adjusting the pressure of the control port P of the explosion-proof valve 110; the pressure detection ports E of the two explosion-proof valves 110 are communicated through a pressure compensation acquisition module 140, and the pressure compensation acquisition module 140 is used for balancing the hydraulic pressures of the two explosion-proof valves 110 and detecting the hydraulic pressure of the explosion-proof valves 110; the oil delivery module 130, the pressure compensation acquisition module 140 and the hydraulic control module 150 are all connected with the controller 170, and the controller 170 is used for controlling the oil delivery amount of the oil delivery module 130 or controlling the hydraulic control module 150 to adjust the pressure of the control port P of the explosion-proof valve 110 according to the hydraulic pressure of the explosion-proof valve 110.

The explosion-proof valve 110 plays a critical role in ensuring the safety operation of engineering machinery such as an excavator. When the hydraulic pipeline of the high-pressure oil to the oil cylinder 120 is broken or the pipe joint is loosened due to frequent actions of the movable arm, the explosion-proof valve 110 can lock the oil cylinder 120 at a fixed position, so that safety accidents caused by rapid falling of the movable arm are avoided. The oil delivery module 130 may power the oil cylinder 120 so that the oil cylinder 120 may control the boom up or down. The pressure compensation acquisition module 140 can balance the hydraulic pressure of the two explosion-proof valves 110 to eliminate the phenomenon that the two oil cylinders 120 control the movable arm to generate unbalanced load due to the flow difference; the pressure compensation acquisition module 140 may also detect the hydraulic pressure of the explosion proof valve 110 to be fed back to the controller 170 in real time so that the controller 170 adjusts the operation of the boom hydraulic system in real time according to the hydraulic pressure of the explosion proof valve 110. The oil delivery control module 160 may control the oil delivery module 130 to deliver oil to the rod cavity of the oil cylinder 120 or the rodless cavity of the oil cylinder 120 through different oil delivery path ports. For example, the oil delivery control module 160 may communicate an oil delivery path port in communication with a rod cavity of the cylinder 120 to deliver oil to the rod cavity of the cylinder 120; the oil delivery control module 160 may communicate with an oil delivery path port in communication with the explosion-proof valve 110 to deliver oil to the rodless cavity of the cylinder 120 through the explosion-proof valve 110. The hydraulic control module 150 can adjust the pressure of the control port P of the explosion-proof valve 110, so that the oil cylinder 120 can control the boom to descend and ensure that the oil in the rodless cavity of the oil cylinder 120 can return oil through the explosion-proof valve 110 (oil return refers to the return of the oil into the oil tank containing the oil). The controller 170 may control the oil delivery amount of the oil delivery module 130 according to the hydraulic pressure of the explosion-proof valve 110, or control the hydraulic control module 150 to adjust the pressure of the control port P of the explosion-proof valve 110.

The working conditions of the movable arm hydraulic system are as follows: 1) The movable arm is normally lifted; 2) The movable arm is normally lowered; 3) A boom holder; 4) The oil inlet pipeline of the lifting arm bursts; 5) The movable arm descends to burst the oil return pipeline. The following describes the operation of the boom hydraulic system with respect to the above several working conditions of the boom hydraulic system:

1) When the movable arm is normally lifted, the operation condition of the movable arm hydraulic system is as follows: the oil delivery control module 160 controls the first oil delivery path port of the oil delivery module 130 to be conducted, and high-pressure oil output by the first oil delivery path port of the oil delivery module 130 is input into the rodless cavity of the oil cylinder 120 through the oil inlet A of the explosion-proof valve 110 and the oil outlet C of the explosion-proof valve 110, and high pressure of the rodless cavity flows into the oil delivery module 130 to return oil. When the boom is overloaded during the process of lifting, the hydraulic pressure of the rodless cavity of the oil cylinder 120 can be lifted, at this time, the rodless cavity of the oil cylinder 120 returns oil through the overload overflow valve of the explosion-proof valve 110, and meanwhile, the controller 170 can control the oil delivery module 130 to reduce the oil delivery amount according to the hydraulic pressure of the explosion-proof valve 110 collected by the pressure compensation collection module 140, so that the overload of the boom is doubly protected.

2) When the movable arm normally descends, the operation condition of the movable arm hydraulic system is as follows: the oil delivery control module 160 controls the second oil delivery path port of the oil delivery module 130 to be conducted, high-pressure oil output by the second oil delivery path port of the oil delivery module 130 is input into the rod cavity of the oil cylinder 120, at this time, the controller 170 controls the hydraulic control module 150 to adjust the pressure of the control port P of the explosion-proof valve 110 according to the hydraulic pressure of the explosion-proof valve 110 acquired by the pressure compensation acquisition module 140, so that oil in the rodless cavity of the oil cylinder 120 can flow back to the oil delivery module 130 through the oil inlet a of the explosion-proof valve 110 for oil return. Wherein, the descending speed of the movable arm can be adjusted by the hydraulic control module 150, and when the hydraulic control module 150 adjusts the pressure of the control port P of the explosion-proof valve 110 to be increased, the descending speed of the movable arm can be increased; when the hydraulic control module 150 adjusts the pressure of the control port P of the explosion-proof valve 110 to decrease, the boom-down speed may decrease.

3) When the movable arm is kept, the operation condition of the movable arm hydraulic system is as follows: the boom holding means that the boom is fixed at a certain position after the boom is lifted to a certain position, and cannot automatically fall. At this time, the explosion-proof valve 110 may perform a function of holding the boom, and when the boom is lifted to a certain position, the first oil delivery path of the oil delivery module 130 stops delivering oil to the rodless cavity of the oil cylinder 120, and at this time, the oil in the rodless cavity of the oil cylinder 120 cannot return oil through the explosion-proof valve 110, so that the holding of the boom may be implemented. If the load is too large or the boom is subjected to severe impact or vibration during the holding period, the pressure of the rodless cavity of the oil cylinder 120 can be increased, and when the pressure of the rodless cavity of the oil cylinder 120 exceeds a certain value, the overflow valve of the explosion-proof valve 110 can be conducted, so that the oil in the rodless cavity of the oil cylinder 120 overflows to flow back to the oil tank, and the stability of the arm hydraulic system is improved.

4) When the oil inlet pipeline bursts when the movable arm rises, the operation condition of the movable arm hydraulic system is as follows: if the oil inlet pipe bursts suddenly, the oil delivery module 130 cannot deliver oil to the rodless cavity of the oil cylinder 120 at this time, the first oil delivery path of the oil delivery module 130 stops delivering oil to the rodless cavity of the oil cylinder 120, and oil in the rodless cavity of the oil cylinder 120 cannot return through the explosion-proof valve 110, so that the movable arm is controlled to be locked at a position where the movable arm runs when the pipeline breaks, and the condition that the movable arm drops quickly due to the burst of the pipeline is prevented.

5) When the boom descending oil return pipeline bursts, the operation condition of the boom hydraulic system is as follows: at the moment of explosion of the boom-down oil return pipeline, under the control of the hydraulic control module 150, the oil return flow rate of the rodless cavity of the oil cylinder 120 through the explosion-proof valve 110 is increased sharply, namely, the oil outlet C to the oil inlet A of the explosion-proof valve 110 is increased sharply. The pressure compensation acquisition module 140 can detect the abrupt increase of the hydraulic pressure of the explosion-proof valve 110, and the controller 170 can cut off the pressure regulation of the hydraulic control module 150 to the control port P of the explosion-proof valve 110 according to the hydraulic pressure of the explosion-proof valve 110, so as to cut off the oil return of the rodless cavity of the oil cylinder 120, thereby preventing the outflow of oil liquid and the damage of the outside air to the hydraulic arm hydraulic system in the oil cylinder 120.

According to the movable arm hydraulic system provided by the embodiment of the invention, the oil delivery control module 160 can control the oil delivery module 130 to conduct different oil delivery path ports to the rod cavity of the oil cylinder 120 or the rodless cavity of the oil cylinder 120 for delivering oil, so that the lifting control of the oil cylinder 120 on the movable arm is realized. The pressure compensation acquisition module 140 not only can balance the hydraulic pressure of the two explosion-proof valves 110 to eliminate the phenomenon that the two oil cylinders 120 control the movable arm to have unbalanced load due to the flow difference, but also can detect the hydraulic pressure of the explosion-proof valves 110 in real time and feed back the hydraulic pressure to the controller 170 in time, so that the controller 170 can adjust the operation of the movable arm hydraulic system in real time according to the hydraulic pressure of the explosion-proof valves 110, thereby improving the operation stability of the movable arm hydraulic system. The hydraulic control module 150 may reduce pressure fluctuation of the cylinder 120 and pressure impact received by the cylinder 120 under the control of the controller 170, thereby reducing a leakage failure rate of the cylinder 120 and further improving operation stability of the boom hydraulic system. In addition, the movable arm hydraulic system composed of the two explosion-proof valves 110, the two oil cylinders 120, the oil delivery module 130, the pressure compensation acquisition module 140, the hydraulic control module 150, the oil delivery control module 160 and the controller 170 can lock the movable arm at a fixed position in time under the conditions of overload of the movable arm, burst of an oil inlet pipeline for ascending the movable arm, burst of an oil return pipeline for descending the movable arm and the like, so that the safety of the movable arm hydraulic system is improved.

Illustratively, on the basis of the above embodiment, fig. 3 is a schematic structural diagram of a boom hydraulic system according to an embodiment of the present invention, wherein, as shown in fig. 3, a pressure compensation acquisition module 140 includes a pressure sensor 141 and a pressure compensation hydraulic pipe 142; the pressure detection ports E of the two explosion-proof valves 110 are communicated through a pressure compensation hydraulic pipe 142, and the pressure compensation hydraulic pipe 142 is used for balancing the hydraulic pressures of the two explosion-proof valves 110; the pressure sensor 141 is connected to a pressure detection port E for detecting the hydraulic pressure of the explosion-proof valve 110.

However, in the prior art, it is difficult to achieve synchronization of controlling the motions of the boom at the same time by installing a plurality of cylinders 120, but the lifting motion of one boom is generally responsible for two cylinders 120 on the excavator. When the boom is lowered, if the hydraulic pressures of the rodless chambers of the two cylinders 120 are different, the difference of the flow rates of the return oil of the rodless chambers of the two cylinders 120 is caused, and unbalanced load is likely to occur when the cylinders 120 control the boom to be lowered. Similarly, when the boom is raised, if the oil feed rates of the rodless chambers of the two cylinders 120 are different, so that the hydraulic pressures of the rodless chambers of the cylinders 120 are different, unbalanced load is likely to occur when the cylinders 120 control the boom to be raised. To the above problem, this patent will increase the pressure detection mouth E of two explosion-proof valves 110 of pressure compensation hydraulic pipe 142 intercommunication to balance the hydraulic pressure of two explosion-proof valves 110, thereby make the rodless chamber of two hydro-cylinders 120 have the same hydraulic pressure and flow, and then make the swing arm of two hydro-cylinders 120 control act in step in the lift process, thereby avoid appearing the phenomenon of unbalance loading.

Optionally, with continued reference to fig. 3, the oil delivery module 130 includes a swing arm-to-link reversing valve 131 and a main pump 132; the main pump 132 is connected with an oil inlet A of the movable arm linkage reversing valve 131, a first oil port of the movable arm linkage reversing valve 131 is used as the first oil transportation path port, and a second oil port of the movable arm linkage reversing valve 131 is used as the second oil transportation path port; the oil delivery control module 160 is communicated with the pilot port of the movable arm linkage reversing valve 131, and the oil delivery control module 160 is used for controlling the hydraulic pressure of the pilot port of the movable arm linkage reversing valve 131 so as to control the first oil port or the second oil port which is communicated with the movable arm linkage reversing valve 131 to deliver oil; a controller 170 is connected to the main pump 132, and the controller 170 is configured to control the oil delivery amount of the main pump 132 according to the hydraulic pressure of the explosion-proof valve 110.

Specifically, the first oil port of the swing arm linkage directional valve 131 is communicated with the oil inlet a of each explosion-proof valve 110, and the oil return port R of each explosion-proof valve 110 and the rod cavity of each oil cylinder 120 are communicated with the second oil port of the swing arm linkage directional valve 131. Assuming that the oil delivery control module 160 controls the hydraulic pressure of the pilot port of the swing arm linkage directional valve 131 to reach a first threshold value, the swing arm linkage directional valve 131 conducts the first oil port; the oil delivery control module 160 controls the hydraulic pressure of the pilot port of the swing arm linkage directional valve 131 to reach a second threshold value, and the swing arm linkage directional valve 131 conducts the second oil port. When the first oil port is conducted, the oil output from the first oil port is output to the rodless cavity of the oil cylinder 120 through the oil inlet A and the oil outlet C of the explosion-proof valve 110, the oil in the rod cavity of the oil cylinder 120 flows back, and at this time, the oil cylinder 120 can control the lifting arm to lift. When the second oil port is conducted, the oil output by the second oil port is output to the rod cavity of the oil cylinder 120, the oil in the rodless cavity of the oil cylinder 120 flows back through the on-off valve of the explosion-proof valve 110, and at the moment, the oil cylinder 120 can control the movable arm to descend.

The hydraulic pressure of the rodless cavity of the oil cylinder 120 will rise when the boom is overloaded in the process of rising, at this time, the rodless cavity of the oil cylinder 120 will return oil through the overload relief valve of the explosion-proof valve 110, and meanwhile, the controller 170 will control the oil delivery module 130 to reduce the oil delivery amount according to the hydraulic pressure of the explosion-proof valve 110 collected by the pressure compensation collection module 140, so as to play a dual protection role on the overload of the boom.

Optionally, with continued reference to fig. 3, the oil delivery control module 160 includes a proportional reversing valve 161 and a proportional valve 162; the swing arm linkage directional valve 131 further includes a first pilot port and a second pilot port; the first delivery port of the proportional directional valve 161 is communicated with the first pilot port, the second delivery port of the proportional directional valve 161 is communicated with the second pilot port, the proportional valve 162 is communicated with the proportional directional valve 161, and the proportional valve 162 is used for adjusting the proportional directional valve 161 to deliver pilot oil to the first pilot port or the second pilot port so as to adjust the hydraulic pressure of the first pilot port or the second pilot port.

In fig. 3, the proportional valve 162 may set the pilot pressure for reversing the spool of the boom linkage reversing valve 131, if the electromagnet at the right end of the proportional reversing valve 161 is powered, that is, the right position works, the pilot oil is delivered to the first pilot port of the boom linkage reversing valve 131 through the first delivery port of the proportional reversing valve 161, and the pilot oil pushes the spool of the boom linkage reversing valve 131 to conduct the first oil port in the process of increasing the hydraulic pressure. If the electromagnet at the left end of the proportional reversing valve 161 is powered on, that is, the right position works, the pilot oil is conveyed to the second pilot port of the movable arm linkage reversing valve 131 through the second conveying port of the proportional reversing valve 161, and the pilot oil pushes the valve core of the movable arm linkage reversing valve 131 to conduct the second oil port in the process of continuously increasing the hydraulic pressure.

Optionally, with continued reference to fig. 3, the hydraulic control module 150 includes a proportional pressure reducing valve 151 and a solenoid on-off valve 152; the proportional pressure reducing valve 151 is communicated with the electromagnetic switch valve 152, the electromagnetic switch valve 152 is communicated with the control port P of each explosion-proof valve 110, the proportional pressure reducing valve 151 and the electromagnetic switch valve 152 are connected with the controller 170, the controller 170 is used for controlling the hydraulic pressure of pilot oil fed to the electromagnetic switch valve 152 by the proportional pressure reducing valve 151, and the controller 170 is used for controlling the hydraulic pressure of the pilot oil fed to the control port P by the electromagnetic switch valve 152.

When the boom descends, the controller 170 controls the proportional pressure reducing valve 151 and the electromagnetic switch valve 152 to be conducted according to a certain proportion, so as to adjust the pressure of the control port P of the explosion-proof valve 110, and the oil in the rodless cavity of the oil cylinder 120 can flow back to the oil delivery module 130 through the oil inlet a of the explosion-proof valve 110 for oil return. Wherein, the descending speed of the movable arm can be adjusted by the proportional pressure reducing valve 151 and the electromagnetic switch valve 152, when the conducting ports of the proportional pressure reducing valve 151 and the electromagnetic switch valve 152 are increased, the pressure of the control port P of the adjusting explosion-proof valve 110 is increased, and the descending speed of the movable arm is increased; when the conduction ports of the proportional pressure reducing valve 151 and the electromagnetic opening/closing valve 152 are reduced, the pressure of the control port P of the regulator explosion-proof valve 110 is reduced, and the boom lowering speed is lowered.

Optionally, with continued reference to fig. 3, the boom hydraulic system further includes a pilot pump 180, based on the above-described embodiments; both the hydraulic control module 150 and the oil delivery control module 160 are in communication with a pilot pump 180, the pilot pump 180 being used to deliver pilot oil to the hydraulic control module 150 or the oil delivery control module 160.

It should be noted that: the pilot oil delivered by pilot pump 180 is the same as the oil delivered by oil delivery module 130.

Optionally, with continued reference to fig. 3, the boom hydraulic system further includes a pilot filter 190, in addition to the above-described embodiments; the pilot filter 190 is connected to the pilot pump 180, and the hydraulic control module 150 and the oil delivery control module 160 are connected to the pilot filter 190, and the pilot filter 190 is used for filtering the pilot oil.

Optionally, with continued reference to fig. 3, the boom hydraulic system further includes a tank 210; each of the explosion-proof valve 110, the oil delivery module 130, the hydraulic control module 150 and the oil delivery control module 160 is connected to an oil tank 210, the oil tank 210 is used for supplying oil to the oil delivery module 130, the hydraulic control module 150 and the oil delivery control module 160, and the oil tank 210 is also used for receiving return oil from the explosion-proof valve 110, the oil delivery module 130, the hydraulic control module 150 and the oil delivery control module 160.

Optionally, with continued reference to fig. 3, the boom hydraulic system further includes a check valve 220, based on the above-described embodiments; the main pump 132 is communicated with the movable arm linkage directional valve 131 through a check valve 220, and the check valve 220 is used for controlling the oil delivery direction of the main pump 132 and the movable arm linkage directional valve 131.

With continued reference to fig. 3, the working principles of the working conditions of normal boom up, normal boom down, boom hold, boom up oil inlet pipe bursting and boom down oil return pipe bursting are further described according to the specific connection relation:

1) The movable arm rises normally, and the operation condition of the movable arm hydraulic system is as follows: the pilot pump 180 outputs pilot oil, which is filtered by the pilot filter 190 and then is regulated to pilot pressure for reversing the valve core of the movable arm linkage reversing valve 131 by the proportional valve 162, at this time, the electromagnet at the right end of the proportional reversing valve 161 is powered on, the pilot pressure oil is conveyed to the first pilot port of the movable arm linkage reversing valve 131 by the first conveying port of the proportional reversing valve 161, the valve core of the movable arm linkage reversing valve 131 is pushed by the pilot oil to conduct the first oil port in the process of continuously increasing hydraulic pressure, high-pressure oil output by the main pump 132 is respectively conveyed to the rodless cavity of the oil cylinder 120 through the first oil port, the oil inlet A of the movable arm explosion-proof valve 110 and the oil outlet C of the movable arm explosion-proof valve 110, and oil in the rod cavity of the oil cylinder 120 is returned by the movable arm linkage reversing valve 131, so that the movable arm lifting action is completed. At this time, the controller 170 does not receive the boom down signal, so that the current of the proportional pressure reducing valve 151 is 0mA, the output pressure is 0MPa, the control port P of the explosion-proof valve 110 is not pressurized, the on-off valve of the explosion-proof valve 110 is not turned on, and no high pressure oil passes. When the boom rises and meets excessive load, the pressure of the rodless cavity of the oil cylinder 120 is increased, if the rated working pressure of the oil cylinder 120 is exceeded, high-pressure oil overflows the oil return tank 210 through the overflow valve of the explosion-proof valve 110, meanwhile, the hydraulic pressure of the explosion-proof valve 110 is collected and transmitted to the controller 170 through the pressure sensor 141, and the controller 170 sends out corresponding instructions to control the main pump 132 to reduce the displacement, so that the protection effect is achieved when the boom is overloaded.

2) The movable arm normally descends, and the operation condition of the movable arm hydraulic system is as follows: the pilot pump 180 outputs pilot oil, which is filtered by the pilot filter 190 and then is regulated to be pilot pressure for reversing the valve core of the movable arm linkage reversing valve 131 by the proportional valve 162, at this time, the electromagnet at the left end of the proportional reversing valve 161 is electrified, the pilot pressure oil is conveyed to the second pilot port of the movable arm linkage reversing valve 131 by the second conveying port of the proportional reversing valve 161, the pilot oil pushes the valve core of the movable arm linkage reversing valve 131 to conduct the second oil port in the process of continuously increasing hydraulic pressure, high-pressure oil output by the main pump 132 is conveyed to a rod cavity of the oil cylinder 120 by the second oil port, at this time, the controller 170 sends a corresponding movable arm descending signal according to the pressure value of the sensor, the proportional pressure reducing valve 151 and the electromagnetic switch valve 152 conduct and output corresponding pilot liquid to the control port P of the explosion-proof valve 110 so as to adjust the pressure of the control port P of the explosion-proof valve 110, so that the on-off method of the explosion-proof valve 110 is conducted, and the high-pressure oil of the rodless cavity of the oil cylinder 120 can pass through the on-off valve of the explosion-proof valve 110 to the oil inlet A of the explosion-proof valve 110, and finally return oil is carried out by the movable arm linkage reversing valve 131, and the movable arm is lowered. Wherein, the descending speed of the movable arm can be adjusted according to the pressure of the pilot fluid output by the proportional pressure reducing valve 151 and the electromagnetic switch valve 152, when the movable arm is required to descend rapidly, the controller 170 increases the output current to the electromagnets of the proportional pressure reducing valve 151 and the electromagnetic switch valve 152, the conduction ports of the proportional pressure reducing valve 151 and the electromagnetic switch valve 152 are increased, the output pilot fluid is increased, the pilot fluid pressure is increased, the opening of the on-off valve of the explosion-proof valve 110 is increased, the return oil quantity of the rodless cavity of the oil cylinder 120 is increased, and the descending speed of the movable arm is increased; when the boom is required to be slowly lowered, the controller 170 reduces the output current to the electromagnets of the proportional pressure reducing valve 151 and the electromagnetic switch valve 152, the conduction ports of the proportional pressure reducing valve 151 and the electromagnetic switch valve 152 are reduced, the output pilot liquid is reduced, the pilot liquid pressure is reduced, the opening of the on-off valve of the explosion-proof valve 110 is reduced, the oil return amount of the rodless cavity of the oil cylinder 120 is reduced, and the boom lowering speed is reduced.

3) The movable arm is maintained, and the operation condition of the movable arm hydraulic system is as follows: when the movable arm is lifted to a certain position, the movable arm needs to be fixed at a certain position, and the movable arm cannot automatically fall. The explosion proof valve 110 may then function as a load retainer. After the movable arm is lifted to a certain position, the electromagnets of the proportional reversing valve 161 and the electromagnetic switching valve 152 are powered off, the proportional reversing valve 161 and the electromagnetic switching valve 152 are not conducted, at the moment, the pressure of the direct return oil tank 210 of the pilot pressure oil is 0MPa, and the on-off valve in the explosion-proof valve 110 is not conducted; the first pilot port and the second pilot port of the swing arm linkage directional valve 131 are free of pilot oil, and the first oil port and the second oil port of the swing arm linkage directional valve 131 are not communicated. Since both the on-off valve and the check valve 220 in the explosion-proof valve 110 are cone-sealed, oil of the rodless chamber of the cylinder 120 cannot leak through the explosion-proof valve 110, and thus, the boom retention can be achieved. If the load is excessive during boom hold or the ram 120 is subjected to severe shock or vibration, the rodless cavity pressure of the ram 120 increases. When the pressure of the rodless cavity of the oil cylinder 120 exceeds a certain value, high-pressure oil in the rodless cavity of the oil cylinder 120 overflows the oil return tank 210 through the overflow valve of the explosion-proof valve 110, so that protection of the movable arm hydraulic system is realized.

4) The movable arm lifting oil inlet pipeline bursts, and the running condition of the movable arm hydraulic system is as follows: in the lifting process of the movable arm, if the oil inlet pipeline suddenly bursts, at the moment, the electromagnet at the right end of the proportional reversing valve 161 is electrified, the pilot pressure oil is conveyed to the first pilot port of the movable arm linkage reversing valve 131 through the first conveying port of the proportional reversing valve 161, and the pilot oil pushes the valve core of the movable arm linkage reversing valve 131 to conduct the first oil port in the process of continuously increasing the hydraulic pressure, but at the moment, the high-pressure oil of the main pump 132 cannot be conveyed to the rodless cavity of the movable arm oil cylinder 120 through the pipeline, and meanwhile, because the on-off valve in the explosion-proof valve 110 is in a non-conducting state, the oil in the rodless cavity of the oil cylinder 120 cannot leak through the explosion-proof valve 110, so that the movable arm can be quickly locked at the position of the movable arm when the oil inlet pipeline bursts, and the condition that the movable arm drops quickly due to the pipeline burst is prevented.

5) The boom lowering oil return pipeline bursts, and the operation condition of the boom hydraulic system is as follows: at the moment that the oil return pipeline bursts when the movable arm descends, the on-off valve of the explosion-proof valve 110 is conducted, and after the oil return pipeline bursts, the pressure of an oil inlet A of the explosion-proof valve 110 is 0MPa, the flow from an oil outlet C port to an oil inlet A of the explosion-proof valve 110 can be increased sharply, the pressure sensor 141 can detect the pressure which rises sharply and send the pressure to the controller 170, the controller 170 can turn off the proportional reducing valve 151, so that the on-off valve of the explosion-proof valve 110 is turned off, an oil return way is cut off, and oil outflow and external air are prevented from entering the hydraulic cylinder 120 to damage a hydraulic system.

The embodiment of the invention also provides an excavator, which comprises the movable arm hydraulic system provided by any embodiment of the invention, and has corresponding beneficial effects, and the description is omitted here.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims (10)

1. The movable arm hydraulic system is characterized by comprising two explosion-proof valves, two oil cylinders, an oil transportation module, a pressure compensation acquisition module, a hydraulic control module, an oil transportation control module and a controller;

the rodless cavity of each oil cylinder is communicated with an oil outlet of one explosion-proof valve, an oil inlet of each explosion-proof valve is communicated with a first oil conveying path port of the oil conveying module, the rod cavities of the two oil cylinders and an oil return port of the explosion-proof valve are both communicated with a second oil conveying path port of the oil conveying module, the oil conveying control module is communicated with the oil conveying module, and the oil conveying control module is used for controlling the oil conveying module to conduct oil conveying of the first oil conveying path port or the second oil conveying path port; the hydraulic control module is communicated with the control port of the explosion-proof valve and is used for adjusting the pressure of the control port of the explosion-proof valve; the pressure detection ports of the two explosion-proof valves are communicated through the pressure compensation acquisition module, and the pressure compensation acquisition module is used for balancing the hydraulic pressures of the two explosion-proof valves and detecting the hydraulic pressure of the explosion-proof valves; the oil transportation module, the pressure compensation acquisition module and the hydraulic control module are all connected with the controller, and the controller is used for controlling the oil transportation amount of the oil transportation module or controlling the hydraulic control module to adjust the pressure of a control port of the explosion-proof valve according to the hydraulic pressure of the explosion-proof valve.

2. The boom hydraulic system of claim 1, wherein the pressure compensation acquisition module comprises a pressure sensor and a pressure compensation hydraulic line;

the pressure detection ports of the two explosion-proof valves are communicated through the pressure compensation hydraulic pipe, and the pressure compensation hydraulic pipe is used for balancing the hydraulic pressures of the two explosion-proof valves;

the pressure sensor is connected with the pressure detection port, and the pressure detection port is used for detecting the hydraulic pressure of the explosion-proof valve.

3. The boom hydraulic system of claim 1, wherein the oil delivery module comprises a boom linkage reversing valve and a main pump;

the main pump is connected with an oil inlet of the movable arm linkage reversing valve, a first oil port of the movable arm linkage reversing valve is used as the first oil transportation path port, and a second oil port of the movable arm linkage reversing valve is used as the second oil transportation path port;

the oil transportation control module is communicated with a pilot port of the movable arm linkage reversing valve and is used for controlling the hydraulic pressure of the pilot port of the movable arm linkage reversing valve so as to control the first oil port or the second oil port of the movable arm linkage reversing valve to be communicated;

the controller is connected with the main pump and is used for controlling the oil delivery amount of the main pump according to the hydraulic pressure of the explosion-proof valve.

4. The boom hydraulic system of claim 3, wherein the oil delivery control module comprises a proportional reversing valve and a proportional valve;

the movable arm linkage reversing valve further comprises a first guide port and a second guide port;

the first conveying port of the proportional reversing valve is communicated with the first pilot port, the second conveying port of the proportional reversing valve is communicated with the second pilot port, the proportional valve is communicated with the proportional reversing valve, and the proportional valve is used for adjusting the proportional reversing valve to convey pilot oil to the first pilot port or the second pilot port so as to adjust the hydraulic pressure of the first pilot port or the second pilot port.

5. The boom hydraulic system of claim 1, wherein the hydraulic control module includes a proportional pressure relief valve and a solenoid on-off valve;

the proportional pressure reducing valve is communicated with the electromagnetic switch valves, the electromagnetic switch valves are communicated with the control ports of each explosion-proof valve, the proportional pressure reducing valve and the electromagnetic switch valves are connected with the controller, the controller is used for controlling the hydraulic pressure of pilot oil which is delivered to the electromagnetic switch valves by the proportional pressure reducing valves, and the controller is used for controlling the hydraulic pressure of the pilot oil which is delivered to the control ports by the electromagnetic switch valves.

6. The boom hydraulic system of claim 1, further comprising a pilot pump;

the hydraulic control module and the oil delivery control module are communicated with the pilot pump, and the pilot pump is used for delivering pilot oil to the hydraulic control module or the oil delivery control module.

7. The boom hydraulic system of claim 6, further comprising a pilot filter;

the pilot filter is connected with the pilot pump, the hydraulic control module and the oil delivery control module are both connected with the pilot filter, and the pilot filter is used for filtering the pilot oil.

8. The boom hydraulic system of claim 1, further comprising a tank;

each explosion-proof valve, the oil delivery module, the hydraulic control module and the oil delivery control module are all connected with the oil tank, the oil tank is used for supplying oil to the oil delivery module, the hydraulic control module and the oil delivery control module, and the oil tank is also used for receiving backflow oil of the explosion-proof valve, the oil delivery module, the hydraulic control module and the oil delivery control module.

9. The boom hydraulic system of claim 3, further comprising a check valve;

the main pump is communicated with the movable arm linkage reversing valve through the one-way valve, and the one-way valve is used for controlling the oil conveying direction of the main pump and the movable arm linkage reversing valve.

10. An excavator comprising the boom hydraulic system of any one of claims 1-9.