Hydraulic system based on composite multi-way valve cooperative control variable pump and rotary drilling rig

Abstract

The application discloses a hydraulic system based on a composite multi-way valve cooperative control variable pump and a rotary drilling rig, and relates to the technical field of hydraulic control. In the hydraulic system, a first multi-way valve comprises a first shuttle valve, a neutral oil drain valve, a load-sensitive oil drain valve and a plurality of post-valve compensation working links; a second multi-way valve comprises a plurality of second shuttle valves and pre-valve compensation working links; output oil ports of the pump are connected with two oil inlet ports respectively; the post-valve compensation working links are connected with the first shuttle valve and the load-sensitive oil drain valve; the first shuttle valve is connected with a second feedback oil port and a third feedback oil port; the third feedback oil port is connected with a fifth feedback oil port; the fifth feedback oil port is connected with the neutral oil drain valve and a first feedback oil port; the first feedback oil port is connected with a control port of the pump; the second shuttle valve is connected with a fourth feedback oil port; and the fourth feedback oil port is connected with the second feedback oil port. The hydraulic system can meet the differentiated control requirements of small-flow auxiliary actions and large-flow main actions in a small space and low-cost mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control, in particular to a hydraulic system based on a composite multi-way valve and a variable pump and a rotary drilling rig. BACKGROUND

[0002] In a hydraulic system, load sensing control technology adjusts the output flow of the pump in real time by detecting the load feedback pressure to meet the supply of different flow requirements. The variable pump only needs to output a pressure value slightly larger than the load pressure to drive the actuator, and the speed regulating system is not affected by the load, the handle operation has no dead zone, and the starting and operating performance is good. Compared with the throttling (positive and negative flow) control technology, the load sensing control technology has the advantages of small energy loss and good speed regulating performance.

[0003] In the prior art, there are two kinds of multi-way control valves matched with load sensing pumps: one is a pre-valve secondary pressure compensation multi-way control valve. The compensation valve opening of the multi-way control valve is only related to the throttle valve opening and the compensation valve return spring force, and is not affected by the change of the load pressure. The multi-way control valve can accurately and stably output the flow corresponding to the operation handle when a single actuation operation is performed, and can avoid flow fluctuation when the load changes. The other is a post-valve secondary pressure compensation multi-way control valve. The compensation valve opening of the multi-way control valve is related to the throttle valve opening and the change of the load pressure. The flow stability of the multi-way control valve when a single actuation operation is performed is poorer than that of the pre-valve secondary pressure compensation multi-way control valve. However, when multiple actions are combined, the compensation valve control pressure depends on the highest pressure in the actuation operation. The compensation valve opening of the actuation operation with low pressure is small, which avoids the reduction of the output pressure of the main pump and ensures the pressure required for the combined action. Since the pre-valve secondary pressure compensation multi-way control valve and the post-valve secondary pressure multi-way control valve realize different functions, the following differences exist between the two in structure:

[0004] Firstly, the compensation valve principles of the two multi-way control valves are different. The compensation valve opening of the pre-valve secondary pressure compensation multi-way control valve depends on the pressure difference formed by the throttle valve opening and the compensation valve return spring force, and the compensation valve opening is stable. The compensation valve opening of the post-valve secondary pressure multi-way control valve depends on the pressure difference formed by the throttle valve opening and the actuation working pressure, and the compensation valve opening is relatively stable when multiple actions are combined.

[0005] Secondly, the pre-valve secondary pressure compensation multi-way control valve generally does not have a multi-way valve mid-position oil drain valve and an LS (load sensing) oil drain valve. When the multi-way valve is in the middle position, the hydraulic pump is in zero displacement output, and the LS feedback pressure is discharged to the tank from the mid-position of the reversing valve. The post-valve secondary pressure multi-way control valve has a multi-way valve mid-position oil drain valve for discharging the minimum displacement of the hydraulic pump to the tank, and the LS feedback pressure is discharged to the tank from the LS oil drain valve throttle.

[0006] However, all actions of the current range extender engineering machinery (such as rotary drilling rigs) including platform rotation, left and right masts, etc. are small flow auxiliary functions, the composite action synchronization requirement is not high, but the single action time flow is required to be accurate and stable, so it is suitable to use the valve before secondary pressure compensation multi-way control valve; and the left and right walking, hoisting, drilling and other actions belong to the main function of large flow, so it is suitable to use the valve after secondary pressure compensation multi-way control valve. Based on this, if the two kinds of multi-way valves are matched with variable pumps for control, the complexity and control cost of the hydraulic system will undoubtedly increase.

[0007] Therefore, how to realize the rotary drilling rig to meet the differentiated control requirements of small flow auxiliary actions (such as platform rotation, mast) and large flow main actions (such as walking, hoisting, drilling) in a small space and low cost way is a technical problem that needs to be solved by those skilled in the art at present. SUMMARY

[0008] The purpose of the present application is to provide a hydraulic system and rotary drilling rig based on composite multi-way valve cooperative control variable pump, which can realize the differentiated control requirements of small flow auxiliary actions (such as platform rotation, mast) and large flow main actions (such as walking, hoisting, drilling) in a small space and low cost way.

[0009] To achieve the above purpose, the present application provides a hydraulic system based on composite multi-way valve cooperative control variable pump, comprising:

[0010] The first multi-way valve comprises a first shuttle valve, a neutral oil drain valve, a load-sensitive oil drain valve and a plurality of valve after compensation working links, and has a first oil inlet, a first feedback oil port, a second feedback oil port, a third feedback oil port and a fifth feedback oil port;

[0011] The second multi-way valve comprises a plurality of second shuttle valves and a plurality of valve before compensation working links, and has a second oil inlet and a fourth feedback oil port;

[0012] The load-sensitive pump has an output oil port and a control port;

[0013] The output oil port is connected with the first oil inlet and the second oil inlet through the first working oil path and the second working oil path respectively, the plurality of valve after compensation working links are connected with the first shuttle valve and the load-sensitive oil drain valve, the first shuttle valve is connected with the second feedback oil port and the third feedback oil port, the third feedback oil port is connected with the fifth feedback oil port through the first feedback oil path, the fifth feedback oil port is connected with the neutral oil drain valve and the first feedback oil port, the first feedback oil port is connected with the control port through the main feedback oil path, the plurality of valve before compensation working links are connected with the plurality of second shuttle valves one by one, the plurality of second shuttle valves are connected with the fourth feedback oil port, and the fourth feedback oil port is connected with the second feedback oil port through the second feedback oil path.

[0014] In some embodiments, the pressure compensation valves in the post-valve compensation working link are post-valve secondary pressure compensation valves, and the standby working chambers of the post-valve secondary pressure compensation valves are communicated with the first feedback oil path through the first shuttle valve.

[0015] In some embodiments, the pressure compensation valves in the pre-valve compensation working link are pre-valve secondary pressure compensation valves, and the standby working chambers of the pre-valve secondary pressure compensation valves are communicated with the second feedback oil path through the corresponding second shuttle valve.

[0016] In some embodiments, the load sensing pump is a swash plate type axial piston pump, and the load sensing pump comprises a variable mechanism for performing a variable action, and the control port is connected with the variable mechanism through the load sensing proportional control valve, so that the load sensing pump is in direct proportion with the opening of the spool of the reversing valve in the post-valve compensation working link or the pre-valve compensation working link.

[0017] In some embodiments, the neutral oil drain valve is a spring return type two-position two-way valve, when the pressure oil of the post-valve compensation working link or the pre-valve compensation working link reaches the fifth feedback oil port, the neutral oil drain valve is closed to prevent the working pressure oil from leaking back to the tank, and when the post-valve compensation working link or the pre-valve compensation working link stops working, the neutral oil drain valve is reset under the action of the pressure oil at the output oil port, so that the pressure oil output by the output oil port is drained back to the tank through the neutral oil drain valve.

[0018] In some embodiments, the first multi-way valve is connected with a first preset flow execution mechanism, and the second multi-way valve is connected with a second preset flow execution mechanism, the first preset flow execution mechanism comprises one or more of a walking motor and a main winch, and the second preset flow execution mechanism comprises one or more of a platform slewing and a mast cylinder.

[0019] In some embodiments, a damping hole or a throttle valve is arranged between the first feedback oil path and the control port, for adjusting the response speed of the load sensing pump.

[0020] In some embodiments, the first working oil path and the second working oil path are each provided with a check valve or a priority valve, for preventing the pressure oil from flowing in the reverse direction.

[0021] In some embodiments, a selector valve or a logic valve is arranged between the second feedback oil port and the fourth feedback oil port, for preferentially outputting a higher load pressure signal to the main feedback oil path when the first multi-way valve and the second multi-way valve act simultaneously.

[0022] The application also provides a rotary drilling rig comprising the hydraulic system based on the composite multi-way valve coordinated control variable pump according to any one of the above.

[0023] With respect to the above background, the hydraulic system based on the composite multi-way valve cooperative control variable pump provided by the embodiment of the application comprises a first multi-way valve, a second multi-way valve and a load-sensitive pump. The first multi-way valve comprises a first shuttle valve, a middle oil drain valve, a load-sensitive oil drain valve and a plurality of post-valve compensation working links, and has a first oil inlet, a first feedback oil port, a second feedback oil port, a third feedback oil port and a fifth feedback oil port; the second multi-way valve comprises a plurality of second shuttle valves and a plurality of pre-valve compensation working links, and has a second oil inlet and a fourth feedback oil port; and the load-sensitive pump has an output oil port and a control port.

[0024] The output oil port is connected with the first oil inlet and the second oil inlet through a first working oil path and a second working oil path respectively, the plurality of post-valve compensation working links are connected with the first shuttle valve and the load-sensitive oil drain valve, the first shuttle valve is connected with the second feedback oil port and the third feedback oil port, the third feedback oil port is connected with the fifth feedback oil port through a first feedback oil path, the fifth feedback oil port is connected with the middle oil drain valve and the first feedback oil port, the first feedback oil port is connected with the control port through a main feedback oil path, the plurality of pre-valve compensation working links are connected with the plurality of second shuttle valves one by one, the plurality of second shuttle valves are connected with the fourth feedback oil port, and the fourth feedback oil port is connected with the second feedback oil port through a second feedback oil path.

[0025] When the first multi-way valve needs to act with a large flow demand, the working pressure oil output by the load-sensitive pump passes through the first working oil path to the first oil inlet of the first multi-way valve, so that the post-valve compensation working links supply oil to the corresponding actuators to act, at the same time, the feedback pressure oil of the post-valve compensation working links passes through the first shuttle valve from the third feedback oil port to the fifth feedback oil port through the first feedback oil path, the feedback pressure oil triggers the middle oil drain valve to close the oil drain flow channel of the working oil path, so as to prevent the working pressure oil from leaking back to the oil tank, and at the same time, the feedback pressure oil passes through the first feedback oil port to the control port of the load-sensitive pump through the main feedback oil path, so that the load-sensitive pump controls the change of the output flow; when the first multi-way valve with a large flow demand stops acting, the feedback pressure oil of the post-valve compensation working links is discharged from the throttling small hole of the load-sensitive oil drain valve to the oil tank, and after the discharge, the middle oil drain valve is reset under the action of the pump outlet pressure, so that the small flow hydraulic oil output by the load-sensitive pump in the middle is discharged back to the oil tank from the middle oil drain valve.

[0026] When the second multi-way valve controlled small flow actuator starts to work, the working pressure oil output by the load sensing pump passes through the second working oil path to the second inlet of the second multi-way valve, so that the pre-compensated working link of the valve supplies oil to the corresponding actuator, at the same time, the feedback pressure oil of the pre-compensated working link passes through the corresponding second shuttle valve from the fourth feedback oil port to the second feedback oil port through the second feedback oil path, the feedback pressure oil passes through the first feedback oil path from the third feedback oil port to the fifth feedback oil port through the first shuttle valve, the feedback pressure oil triggers the mid-position oil leakage valve to close the oil leakage flow channel of the working oil path, so as to prevent the working pressure oil from leaking back to the tank, at the same time, the feedback pressure oil passes through the main feedback oil path from the first feedback oil port to the control port of the load sensing pump, so that the load sensing pump controls the change of the output flow; when the second multi-way valve stops working, the feedback pressure oil of the pre-compensated working link is discharged from the mid-position of the valve core of the reversing valve of the pre-compensated working link to the tank, after the discharge, the mid-position oil leakage valve is reset under the action of the pump outlet pressure, so that the small flow hydraulic oil output by the load sensing pump in the mid-position is discharged back to the tank through the mid-position oil leakage valve.

[0027] The hydraulic system based on the composite multi-way valve cooperative control variable pump thus arranged, when the load pressure of the actuator controlled by the first multi-way valve or the second multi-way valve changes, the load sensing hydraulic system cross feeds the pressure to the load sensing pump to increase or decrease the output displacement, in this way, on the one hand, the cross feedback of the pre-compensated valve / post-compensated valve to the load sensing pump is realized, both the single stable flow output irrelevant to the load pressure and the stable flow distribution output of multiple composite actions irrelevant to the load pressure are realized, and flexible and variable flow distribution design is achieved, on the other hand, all the device actions of two groups of different requirements are controlled by one load sensing pump, and the installation space and manufacturing cost are saved. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by the provided drawings without creative labor for those skilled in the art.

[0029] Figure 1 The hydraulic principle diagram of the hydraulic system based on the composite multi-way valve cooperative control variable pump in the embodiments of the present application.

[0030] Among them:

[0031] 1-first shuttle valve; 2-first feedback oil path; 3-second feedback oil path; 4-main feedback oil path; 5-first working oil path; 6-load sensing pump; 7-load sensing proportional control valve; 8-second shuttle valve; 9-second multi-way valve; 10-second working oil path; 11-central neutral drain valve; 12-first multi-way valve; 13-first shuttle valve; 14-load sensing drain valve; 15-second shuttle valve; 16-first pressure compensation valve; 17-second pressure compensation valve. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0033] In order for those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0034] Please refer to Figure 1 , Figure 1 The hydraulic principle diagram of the hydraulic system based on the composite multi-way valve cooperative control variable pump in the embodiments of the present application is shown in the figure.

[0035] The hydraulic system based on the composite multi-way valve cooperative control variable pump provided by the embodiments of the present application comprises a first multi-way valve 12, a second multi-way valve 9 and a load sensing pump 6.

[0036] The load sensing pump 6 is used to output working pressure oil to the first multi-way valve 12 and the second multi-way valve 9, and the load sensing pump 6 has an output port P and a control port X.

[0037] The first multi-way valve 12 and the second multi-way valve 9 respectively control the action of the first preset large flow execution mechanism (such as a walking mechanism, a winch) and the second preset small flow execution mechanism (such as a platform slewing, left and right masts). The first multi-way valve 12 is connected with the first preset large flow execution mechanism, the second multi-way valve 9 is connected with the second preset small flow execution mechanism, the first preset large flow execution mechanism comprises one or several of a walking motor and a main winch, and the second preset small flow execution mechanism comprises one or several of a platform slewing and a mast cylinder.

[0038] Specifically, the execution oil cylinder of the walking motor and the main winch can be respectively connected to the first shuttle valve 13 of the multiple valve rear compensation working links in the first multi-way valve 12, and the execution oil cylinder of the platform slewing and the mast can be respectively connected to the second shuttle valve 8 of the multiple valve front compensation working links in the second multi-way valve 9.

[0039] The first multi-way valve 12 comprises a first shuttle valve 1, a neutral drain valve 11, a load-sensitive drain valve 14 and a plurality of parallel valve-post compensation working links, any valve-post compensation working link comprising a first reversing valve 13 and a first pressure compensation valve 16, and the first multi-way valve 12 further has a first oil inlet P1, a first feedback oil port LS1, a second feedback oil port LS2, a third feedback oil port LS3 and a fifth feedback oil port LS5.

[0040] The second multi-way valve 9 comprises a plurality of second shuttle valves 15 and a plurality of valve-front compensation working links, the number of the second shuttle valves 15 being the same as that of the valve-front compensation working links and being connected in one-to-one correspondence, any valve-front compensation working link comprising a second reversing valve 8 and a second pressure compensation valve 17, and the second multi-way valve 9 further has a second oil inlet P2 and a fourth feedback oil port LS4.

[0041] The output oil port P is connected with the first oil inlet P1 through the first working oil line 5, and the output oil port P is connected with the second oil inlet P2 through the second working oil line 10, so that the load-sensitive pump 6 delivers working pressure oil to the oil inlets of the first multi-way valve 12 and the second multi-way valve 9 through the first working oil line 5 and the second working oil line 10 respectively.

[0042] The plurality of parallel valve-post compensation working links are connected with the first shuttle valve 1 and the load-sensitive drain valve 14 through pipelines, the first shuttle valve 1 is connected with the second feedback oil port LS2 and the third feedback oil port LS3 through pipelines respectively, the third feedback oil port LS3 is connected with the fifth feedback oil port LS5 through the first feedback oil line 2, the fifth feedback oil port LS5 is connected with the neutral drain valve 11 and the first feedback oil port LS1 through pipelines respectively, the first feedback oil port LS1 is connected with the control port X through the main feedback oil line 4, the plurality of valve-front compensation working links are connected with the plurality of second shuttle valves 15 in one-to-one correspondence, the plurality of second shuttle valves 15 are connected with the fourth feedback oil port LS4, and the fourth feedback oil port LS4 is connected with the second feedback oil port LS2 through the second feedback oil line 3.

[0043] The valve-post compensation working link comprises the first reversing valve 13 and the first pressure compensation valve 16, the first pressure compensation valve 16 in the valve-post compensation working link being a valve-post secondary pressure compensation valve (the valve-post secondary pressure compensation valve being a three-position three-way hydraulic control reversing valve), and the standby working cavity (such as the upper working cavity shown in the figure) of each valve-post secondary pressure compensation valve is communicated with the first shuttle valve 1 and the first feedback oil line 2, so that the feedback pressure oil of the valve-post compensation working link reaches the fifth feedback oil port LS5 through the first shuttle valve 1, the third feedback oil port LS3 and the first feedback oil line 2. Figure 1

[0044] ​The pre-valve compensation working link includes a second directional valve 8 and a second pressure compensation valve 17. The second pressure compensation valve 17 in the pre-valve compensation working link is a pre-valve secondary pressure compensation valve (this pre-valve secondary pressure compensation valve is a three-position three-way hydraulic directional valve). The standby working chamber of each pre-valve secondary pressure compensation valve (e.g.) Figure 1 The upper working chamber shown is connected to the second feedback oil circuit 3 via the corresponding second shuttle valve 15, so that the feedback pressure oil of the valve front compensation working link can reach the second feedback oil port LS2 via the corresponding second shuttle valve 15, the fourth feedback oil port LS4 and the second feedback oil circuit 3, and further reach the fifth feedback oil port LS5 via the first shuttle valve 1, the third feedback oil port LS3 and the first feedback oil circuit 2.

[0045] To facilitate the control of the output oil quantity of the load-sensitive pump 6 according to a preset ratio, the load-sensitive pump 6 can be a swashplate axial piston pump. The load-sensitive pump 6 includes a variable mechanism for performing variable actions. The control port X is connected to the variable mechanism through the load-sensitive proportional control valve 7 so that the output of the load-sensitive pump 6 is proportional to the opening of the directional valve core in the downstream compensation working link or the upstream compensation working link.

[0046] To facilitate the return of the small flow of pressure oil output from outlet port P to the oil tank via the neutral position drain valve 11, the neutral position drain valve 11 is a spring-reset two-position two-way valve. Thus, when the pressure oil from the downstream or upstream compensating linkage reaches the fifth feedback port LS5, the neutral position drain valve 11 closes to prevent the working pressure oil from returning to the oil tank; when the downstream or upstream compensating linkage stops working, the neutral position drain valve 11 resets under the action of the pressure oil at outlet port P, allowing the pressure oil output from outlet port P to return to the oil tank via the neutral position drain valve 11.

[0047] Of course, depending on actual needs, the first shuttle valve 1 and the second shuttle valve 15 mentioned above can both be OR type shuttle valves.

[0048] In this way, the variable output of the load-sensitive pump 6 can be cross-controlled by changing the output of the feedback port and by changing the feedback port of the output through the OR shuttle valve. When the load pressure on the actuator controlled by the first multi-way valve 12 or the second multi-way valve 9 changes, the load-sensitive system cross-feeds pressure to the load-sensitive pump 6 to increase or decrease its output displacement.

[0049] The working principle of the hydraulic system based on the composite multi-way valve coordinated control of the variable pump in this application is explained below with reference to specific working conditions:

[0050] When the first multi-way valve 12 controlled by the large flow action requirement is actuated, the working pressure oil output by the load sensing pump 6 passes through the first working oil way 5 to the first inlet port P1 of the first multi-way valve 12, so that the first reversing valve 13 of the valve rear compensation working link is reversed to supply oil to the corresponding actuator to actuate, at the same time, the feedback pressure oil of each first pressure compensation valve 16 of the valve rear compensation working link passes through the first shuttle valve 1 and pushes the valve core of the first shuttle valve 1 to move to the left, so that the feedback pressure oil passes through the first feedback oil way 2 from the third feedback oil port LS3 to the fifth feedback oil port LS5, the feedback pressure oil first pushes the valve core of the middle relief valve 11 to the right, so as to trigger the middle relief valve 11 to close the relief flow channel of the working oil way, preventing the working pressure oil from leaking back to the oil tank, at the same time, the feedback pressure oil passes through the first feedback oil port LS1 from the main feedback oil way 4 to the control port X of the load sensing pump 6, the output flow of the load sensing pump 6 is controlled by the load sensing proportional control valve 7 on the load sensing pump 6 and is proportional to the opening of the corresponding reversing valve core; when the first multi-way valve 12 controlled by the large flow action requirement is stopped, the feedback pressure oil of the valve rear compensation working link is discharged from the throttling small hole of the load sensing relief valve 14 in the first multi-way valve 12 to the oil tank, after the pressure relief, the middle relief valve 11 is reset under the action of the pump outlet pressure, so that the small flow hydraulic oil output by the load sensing pump 6 is discharged from the middle relief valve 11 back to the oil tank.

[0051] When the second multi-way valve 9 controlled by the small flow actuator starts to work, the working pressure oil output by the load sensing pump 6 passes through the second working oil way 10 to the second inlet port P2 of the second multi-way valve 9, so that the second reversing valve 8 of the valve front compensation working link is reversed to supply oil to the corresponding actuator to actuate, at the same time, the feedback pressure oil of each second pressure compensation valve 17 of the valve front compensation working link passes through the corresponding second shuttle valve 15 and pushes the valve core of the second shuttle valve 15 to move to the right, so that the feedback pressure oil passes from the fourth feedback oil port LS4 to the second feedback oil port LS2 through the second feedback oil way 3, the feedback pressure oil passes from the third feedback oil port LS3 to the fifth feedback oil port LS5 through the first feedback oil way 2, the feedback pressure oil first pushes the valve core of the middle relief valve 11 to the right, so as to trigger the middle relief valve 11 to close the relief flow channel of the working oil way, preventing the working pressure oil from leaking back to the oil tank, at the same time, the feedback pressure oil passes through the first feedback oil port LS1 from the main feedback oil way 4 to the control port X of the load sensing pump 6, the output flow of the load sensing pump 6 is controlled by the load sensing proportional control valve 7 on the load sensing pump 6 and is proportional to the opening of the corresponding reversing valve core; when the second multi-way valve 9 is stopped, the feedback pressure oil of the valve front compensation working link is discharged from the valve core of the second reversing valve 8 of the valve front compensation working link to the oil tank, after the pressure relief, the middle relief valve 11 is reset under the action of the pump outlet pressure, so that the small flow hydraulic oil output by the load sensing pump 6 is discharged from the middle relief valve 11 back to the oil tank.

[0052] The hydraulic system based on the composite multi-way valve coordinated control variable pump is thus arranged. When the load pressure of the actuator controlled by the first multi-way valve 12 or the second multi-way valve 9 changes, the load-sensitive hydraulic system cross feeds the pressure to the load-sensitive pump 6 to increase or decrease the output displacement. In this way, on the one hand, the cross feedback of the load-sensitive pump 6 by the valve pre-compensation / multi-way valve post-compensation is realized, the stable flow output independent of the load pressure is realized, the stable flow distribution output independent of the load pressure of multiple composite actions is realized, the flexible flow distribution design is realized, and on the other hand, all the device actions of two groups with different requirements are controlled by one load-sensitive pump 6, the installation space and manufacturing cost are saved.

[0053] In some embodiments, a damping hole or a throttle valve is arranged between the first feedback oil way 2 and the control port X, for adjusting the response speed of the load-sensitive pump 6.

[0054] In this way, the change rate of the load-sensitive signal is limited by throttling, the swash plate of the variable pump is prevented from swinging sharply due to the load mutation, the flow regulation is smoother, and the method is especially suitable for the working conditions of frequent start and stop of multiple actuators, such as rotary drilling rotation+mast composite action.

[0055] In some embodiments, the first working oil way 5 and the second working oil way 10 are each provided with a one-way valve or a priority valve, for preventing the reverse flow of the pressure oil.

[0056] In this way, the arrangement of the one-way valve can prevent the peak pressure of the high-pressure actuator (such as the walking motor) from flowing back to the low-pressure valve group, and prevent the standby working cavity of the valve pre-pressure compensation valve from losing pressure to cause the flow to be out of control; the priority valve can ensure that the large-flow main action is always preferentially supplied with oil (such as temporarily cutting off the small-flow auxiliary action when the main winch is lifted), and prevent the “oil stealing” from being extinguished.

[0057] In some embodiments, a selector valve or a logic valve is arranged between the second feedback oil port LS2 and the fourth feedback oil port LS4, for preferentially outputting the higher load pressure signal to the main feedback oil way 4 when the first multi-way valve 12 and the second multi-way valve 9 act simultaneously.

[0058] It can be understood that when the valve post-compensation (large flow) and the valve pre-compensation (small flow) act simultaneously, only the highest load pressure is transmitted to the load-sensitive pump 6, the pump outputs the flow as required, and the excess energy consumption caused by the supply of oil according to the highest requirement is avoided. For example, when walking+rotation, the load-sensitive pump 6 only supplies the high pressure required by walking, and the excess flow of rotation is automatically reduced, so that the purpose of reducing system heating and prolonging the service life of the equipment is achieved.

[0059] The rotary drilling rig provided in the application comprises the hydraulic system based on the composite multi-way valve coordinated control variable pump described in the specific embodiments; the other parts of the rotary drilling rig can refer to the related technology, and will not be expanded herein.

[0060] It should be noted that the relational terms herein, such as first and second, are used solely to distinguish one from another entity without necessarily implying any actual relationship or order between such entities.

[0061] The hydraulic system based on the composite multi-way valve coordinated control variable pump and the rotary drilling rig provided by the present application are described in detail above. The principles and implementation manners of the present application are described by applying specific examples in this paper, and the above example descriptions are only used to help understand the scheme of the present application and its core idea. It should be pointed out that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. A hydraulic system based on a composite multiple valve cooperative control of a variable displacement pump, characterized by, The utility model relates to a kind of load sensing pump control system, comprising: First multi-way valve (12), including first shuttle valve (1), mid-position oil drain valve (11), load-sensitive oil drain valve (14) and multiple valve rear compensation working links, and with first oil inlet, first feedback oil port, second feedback oil port, third feedback oil port and fifth feedback oil port; Second multi-way valve (9), including multiple second shuttle valve (15) and multiple valve front compensation working links, and with second oil inlet and fourth feedback oil port; Load-sensitive pump (6), with output oil port and control port; Wherein, the output oil port is connected with the first oil inlet and the second oil inlet by first working oil path (5) and second working oil path (10) respectively, the multiple valve rear compensation working links are connected with the first shuttle valve (1) and the load-sensitive oil drain valve (14), the first shuttle valve (1) is connected with the second feedback oil port and the third feedback oil port, the third feedback oil port is connected with the fifth feedback oil port by first feedback oil path (2), the fifth feedback oil port is connected with the mid-position oil drain valve (11) and the first feedback oil port, the first feedback oil port is connected with the control port by main feedback oil path (4), the multiple valve front compensation working links are connected with the multiple second shuttle valve (15) one by one, the multiple second shuttle valve (15) is connected with the fourth feedback oil port, and the fourth feedback oil port is connected with the second feedback oil port by second feedback oil path (3); The pressure compensation valve in the valve rear compensation working link is a valve rear secondary pressure compensation valve, and the standby working chamber of each valve rear secondary pressure compensation valve is communicated with the first feedback oil path (2) through the first shuttle valve (1). The pressure compensation valve in the valve front compensation working link is a valve front secondary pressure compensation valve, and the standby working chamber of each valve front secondary pressure compensation valve is communicated with the second feedback oil path (3) through the corresponding second shuttle valve (15).

2. The hydraulic system based on a composite multiple valve cooperative control variable pump of claim 1, wherein, The load-sensitive pump (6) is a swash plate type axial piston pump, the load-sensitive pump (6) includes a variable mechanism for performing variable action, the control port is connected with the variable mechanism through load-sensitive proportional control valve (7), so that the load-sensitive pump (6) is proportional to the opening of the reversing valve spool in the valve rear compensation working link or the valve front compensation working link.

3. The hydraulic system based on a composite multiple valve cooperative control of a variable pump of claim 1, wherein, The mid-position oil drain valve (11) is a spring return type two-position two-way valve, when the pressure oil of the valve rear compensation working link or the valve front compensation working link reaches the fifth feedback oil port, the mid-position oil drain valve (11) is closed to prevent the working pressure oil from leaking back to the oil tank, when the valve rear compensation working link or the valve front compensation working link stops working, the mid-position oil drain valve (11) is reset under the action of the pressure oil of the output oil port, so that the pressure oil output by the output oil port leaks back to the oil tank through the mid-position oil drain valve (11).

4. The hydraulic system based on a composite multiple valve cooperative control variable pump of claim 1, wherein, The first multi-way valve (12) is connected with a first preset flow actuator, the second multi-way valve (9) is connected with a second preset flow actuator, the first preset flow actuator comprises one or more of a walking motor and a main winch, and the second preset flow actuator comprises one or more of a platform slewing and a mast cylinder.

5. The hydraulic system based on a complex multi-way valve coordinated control variable pump of any one of claims 1-4, wherein, A damping hole or a throttle valve is arranged between the first feedback oil path (2) and the control port, for adjusting the response speed of the load-sensitive pump (6).

6. The hydraulic system based on a composite multiple valve cooperative control variable pump of any one of claims 1-4, wherein, The first working oil path (5) and the second working oil path (10) are each provided with a one-way valve or a priority valve, for preventing reverse flow of pressure oil.

7. The hydraulic system based on a composite multiple valve cooperative control variable pump of any one of claims 1-4, wherein, A selection valve or a logic valve is arranged between the second feedback oil port and the fourth feedback oil port, for preferentially outputting a higher load pressure signal to the main feedback oil path (4) when the first multi-way valve (12) and the second multi-way valve (9) act simultaneously.

8. A rotary drilling rig, characterized by A hydraulic system based on a composite multi-way valve and a variable pump is provided, comprising the composite multi-way valve according to any one of claims 1-7.

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