阅读说明：本技术 一种带双泵合流功能的负载敏感多路阀 (Load-sensitive multi-way valve with double-pump confluence function ) 是由 张戚 张成星 刘丹 辛少云 丁浩东 于 2021-09-24 设计创作，主要内容包括：一种带双泵合流功能的负载敏感多路阀,涉及直臂随车起重机液压技术领域。包括第一泵进油控制联、比例换向阀工作联、合流控制联、回转换向联和第二泵进油控制联；第一泵进油控制联与第一定量油泵连接,并向比例换向阀工作联供油,第二泵进油控制联与第二定量油泵连接,向回转换向联供油,当回转换向联不工作时,通过单向阀及合流控制联的液控换向阀,使第二定量油泵与第一定量油泵合流,两泵同时向比例换向阀工作联供油,提高作业效率；当回转换向联工作时,合流控制联的液控换向阀切断第二定量油泵与第一定量油泵的合流通道,第二定量油泵向回转换向联独立供油,实现回转动作流量匹配、降低能耗与系统温升。(A load sensitive multi-way valve with a double-pump confluence function relates to the hydraulic technical field of straight-arm lorry-mounted cranes. The system comprises a first pump oil inlet control unit, a proportional reversing valve working unit, a confluence control unit, a rotary reversing unit and a second pump oil inlet control unit; the first pump oil inlet control unit is connected with the first quantitative oil pump and supplies oil to the working unit of the proportional reversing valve, the second pump oil inlet control unit is connected with the second quantitative oil pump and supplies oil to the rotary reversing unit, when the rotary reversing unit does not work, the second quantitative oil pump and the first quantitative oil pump are converged through the check valve and the hydraulic control reversing valve of the confluence control unit, and the two pumps simultaneously supply oil to the working unit of the proportional reversing valve, so that the working efficiency is improved; when the rotary reversing union works, a hydraulic control reversing valve of the confluence control union cuts off a confluence channel of the second quantitative oil pump and the first quantitative oil pump, and the second quantitative oil pump independently supplies oil to the rotary reversing union, so that rotary action flow matching is realized, and energy consumption and system temperature rise are reduced.)

1. A load-sensitive multi-way valve with a double-pump confluence function is characterized by comprising a first pump oil inlet control union (1), a proportional reversing valve working union, a confluence control union (5), a rotary reversing union (6) and a second pump oil inlet control union (7);

the first pump oil inlet control unit (1) supplies oil to the proportional directional valve working unit through a first quantitative oil pump;

the second pump oil inlet control joint (7) supplies oil to the rotary reversing joint (6) through a second quantitative oil pump;

the confluence control joint (5) is arranged between the first pump oil inlet control joint (1) and the second pump oil inlet control joint (7) and controls the confluence of the first quantitative oil pump and the second quantitative oil pump;

the confluence control union (5) comprises a hydraulic control reversing valve (51);

a control oil port of the hydraulic control reversing valve (51) is communicated with an oil port a in the rotary reversing link (6);

the rotary reversing union (6) controls the connection and disconnection of a confluence channel of the first quantitative oil pump and the second quantitative oil pump through the hydraulic control reversing valve (51), so that the second quantitative oil pump independently supplies oil to the rotary reversing union (6) when the rotary reversing union (6) is in a working state.

2. The load-sensitive multi-way valve with dual-pump confluence function as claimed in claim 2, wherein said confluence control block (5) further comprises a damper (52);

the damper (52) is arranged on a spring cavity oil return circuit of the hydraulic control reversing valve (51) and used for controlling the reversing action speed of a valve core of the hydraulic control reversing valve (51).

3. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1, wherein the rotary reversing union (6) comprises a rotary reversing valve (61) and a pressure matcher six (62);

a first working oil port of the rotary reversing valve (61) is communicated with an oil inlet P1 and an oil inlet P2;

a second working oil port of the rotary reversing valve (61) is communicated with an oil return port T1 and an oil return port T2;

the other two working oil ports of the rotary reversing valve (61) are communicated with a pressure matching valve (62);

two working oil ports of the hydraulic control reversing valve (51) are communicated with a first working oil port and a first working oil port of the pressure matcher (62), and the communication of the oil ports MLS1 and MLS2 is realized through the second pump oil inlet control joint (7).

4. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 3, wherein the rotary reversing union (6) further comprises a first pressure-limiting overflow valve six (63) and a second pressure-limiting overflow valve six (64);

one end of the first pressure limiting overflow valve six (63) is communicated with an oil return port T2, and the other end of the first pressure limiting overflow valve six (63) is communicated with an A4 working oil port;

one end of the second pressure limiting overflow valve six (64) is communicated with the oil return port T2, and the other end of the second pressure limiting overflow valve six (64) is communicated with the B4 working oil port.

5. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1, wherein the second pump inlet control union (7) comprises a one-way valve (71), a pressure switching valve (72), a damping seven (73) and a three-way flow valve seven (74);

the oil inlet P2 supplies oil to the rotary reversing joint (6) through the one-way valve (71) and is communicated with an oil inlet of the three-way flow valve seven (74);

an oil outlet of the three-way flow valve seven (74) and the damping seven (73) are respectively communicated with an oil return port T2;

and the load sensitive oil path LS2 is communicated with a spring cavity of the three-way flow valve seven (74) and a working oil port of the damping seven (73) through the pressure switching valve (72).

6. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1, wherein the first pump inlet control union (1) comprises a three-way flow valve I (11), a damping I (13) and a load-sensitive LS oil path pressure-limiting overflow valve (14);

the LS1 control oil way is communicated with the oil return port T1 through a damper (13);

a first working oil port of the three-way flow valve (11) is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

an oil port I of the load-sensitive LS1 oil-way pressure-limiting overflow valve (14) is communicated with an oil return port T1, and an oil port II of the load-sensitive LS1 oil-way pressure-limiting overflow valve is communicated with a load-sensitive oil-way pressure measuring oil port MLS 1;

and a control oil port of the three-way flow valve I (11) is connected to a connection oil path between the load-sensitive LS1 oil path pressure-limiting overflow valve (14) and the load-sensitive oil path pressure-measuring oil port MLS 1.

7. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1, wherein the proportional reversing valve working connection comprises one or a combination of any more of a telescopic reversing connection (2), a winch reversing connection (3) and a variable-amplitude reversing connection (4).

8. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1 or 7, wherein the telescopic reversing union (2) comprises a telescopic reversing valve (21) and a second pressure matcher (22);

a first working oil port of the telescopic reversing valve (21) is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

a control oil port of the second pressure matcher (22) is communicated with a first working oil port and the second pump oil inlet control connector (7);

the telescopic reversing valve (21) is communicated with a second pressure matching valve (22), and the valve port pressure difference of the telescopic reversing valve (21) is controlled through the second pressure matching valve (22) so as to realize the proportional control of the telescopic reversing valve (21).

9. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1 or 7, wherein the winch reversing union (3) comprises a winch reversing valve (31) and a pressure matcher III (32);

a first working oil port of the winch reversing valve (31) is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

a control oil port of the third pressure matcher (32) is communicated with a first working oil port and the second pump oil inlet control connector (7);

the winch reversing valve (31) is communicated with a third pressure matching valve (32), and the valve port pressure difference of the winch reversing valve (31) is controlled through the third pressure matching valve (32) so as to realize the proportional control of the winch reversing valve (31).

10. The load-sensitive multi-way valve with the double-pump confluence function as claimed in claim 1 or 7, wherein the variable-amplitude reversing union (4) comprises a variable-amplitude reversing valve (41) and a pressure matcher four (42);

a first working oil port of the variable amplitude reversing valve (41) is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

a control oil port of the pressure matcher IV (42) is communicated with a working oil port I and the second pump oil inlet control connector (7);

the variable-amplitude reversing valve (41) is communicated with a pressure matching valve IV (42), and the valve port pressure difference of the variable-amplitude reversing valve (41) is controlled through the pressure matching valve IV (42) so as to realize the proportional control of the variable-amplitude reversing valve (41).

Technical Field

The invention relates to the technical field of hydraulic pressure of straight-arm lorry-mounted cranes, in particular to a load-sensitive multi-way valve with a double-pump confluence function.

Background

The straight arm lorry-mounted crane is a multipurpose machine which is arranged on an automobile chassis and can load and unload heavy objects in a certain range, has the characteristics of quickness, flexibility, convenience and integration of hoisting and transportation, and is widely applied to the fields of hoisting and transportation such as equipment loading and unloading, landscaping, municipal construction and the like. In recent years, with the development of markets and technologies, the times of concepts such as high efficiency, high speed, energy conservation and the like are becoming the technical development trend of lorry-mounted cranes.

The main operation actions of the straight-arm lorry-mounted crane comprise stretching, winding, amplitude variation and rotation, and the multi-way valve for getting on the crane is a core element of the hydraulic action control systems. At present, a single oil pump oil supply and proportional multi-way valve control system is adopted in a main stream of a straight boom lorry-mounted crane, requirements for system flow and pressure are greatly different due to main operation actions of the straight boom crane, an existing single pump oil supply system cannot meet requirements for high efficiency, low energy consumption and accurate control, and meanwhile, due to the limitation of the power characteristics of a chassis engine, a large-displacement single pump system cannot solve the problem of engine pressure-holding flameout under high load pressure.

The utility model discloses a patent application No. 202010424973.3 discloses a straight arm is confluence proportion multichannel switching-over valve and working method for lorry crane, gather the load pressure signal from two output working oil ports of switching-over valve of hoist antithetical couplet, first oil pump and second oil pump confluence, the multiway valve device and the working method that all other states do not meet when adopting the hoist action, can only realize the double pump confluence when the hoist action, and the both sides that first pump and second pump are located set up the pressure should be the same, otherwise, when the pressure that one side of gyration allies oneself with was set for is low, confluence state hoist antithetical couplet one side LS oil circuit pressure is drawn low by the pressure of one side of gyration allies oneself with, cause the whole system pressure of confluence state not come; when the pressure settings on the hoisting connection side and the rotation connection side are both high enough, the engine on the engine chassis may be blocked and flamed out due to insufficient output power or torque.

The utility model discloses a lorry crane multiple unit valve switching-over device is disclosed to patent application number 2017109447089.6, and what related to the object is switch type multiple unit valve rather than the proportion core multiple unit valve of this invention, its work antithetical couplet can not compound the operation wantonly, and the action surpasss accuse nature, flow matching nature homodyne, the energy consumption is also big, can not satisfy the requirement of the technological development of present stage lorry crane product.

Disclosure of Invention

Aiming at the problems, the invention provides the load-sensitive multi-way valve with the double-pump confluence function, which has high action efficiency of the straight-arm lorry-mounted crane, avoids engine pressure build-up flameout and ensures stable rotation action during confluence under the rotation joint operation state.

The technical scheme of the invention is as follows: a load-sensitive multi-way valve with a double-pump confluence function comprises a first pump oil inlet control union, a proportional reversing valve working union, a confluence control union, a rotary reversing union and a second pump oil inlet control union;

the first pump oil inlet control communication supplies oil to the working communication of the proportional reversing valve through a first quantitative oil pump;

the second pump oil inlet control communication is communicated with a second quantitative oil pump to supply oil to the rotary reversing union;

the confluence control joint is arranged between the first pump oil inlet control joint and the second pump oil inlet control joint and is used for controlling the confluence of the first quantitative oil pump and the second quantitative oil pump;

the confluence control union comprises a hydraulic control reversing valve;

a control oil port of the hydraulic control reversing valve is communicated with an oil port a in the rotary reversing link;

the rotary reversing union controls the connection and disconnection of a confluence channel of the first quantitative oil pump and the second quantitative oil pump through the hydraulic control reversing valve, so that the second quantitative oil pump independently supplies oil to the switching union when the rotary reversing union is in a working state.

The confluence control joint also comprises damping;

the damping is arranged on a spring cavity oil return oil path of the hydraulic control reversing valve and used for controlling the reversing action speed of a valve core of the hydraulic control reversing valve.

The rotary reversing joint comprises a rotary reversing valve and a pressure matcher six;

a first working oil port of the rotary reversing valve is communicated with an oil inlet P1 and an oil inlet P2;

a second working oil port of the rotary reversing valve is communicated with an oil return port T1 and an oil return port T2;

the other two working oil ports of the rotary reversing valve are communicated with the pressure matching valve;

and two working oil ports of the hydraulic control reversing valve are communicated with the first pressure matcher control oil port and the first working oil port, and the communication of the oil ports MLS1 and MLS2 is realized through the second pump oil inlet control linkage.

The rotary reversing joint also comprises a first pressure-limiting overflow valve six and a second pressure-limiting overflow valve six;

one end of the first pressure limiting overflow valve six is communicated with an oil return port T2, and the other end of the first pressure limiting overflow valve six is communicated with an A4 working oil port;

one end of the second pressure limiting overflow valve six is communicated with the oil return port T2, and the other end of the second pressure limiting overflow valve six is communicated with the B4 working oil port.

The second pump oil inlet control unit comprises a one-way valve, a pressure switching valve, a damping seventh valve and a three-way flow valve seventh valve;

the oil inlet P2 supplies oil to the rotary reversing union through the one-way valve and is communicated with an oil inlet of the three-way flow valve;

an oil outlet and a damping seventh of the three-way flow valve seventh are respectively communicated with an oil return port T2;

and the load sensitive oil path LS2 is communicated with a spring cavity of the three-way flow valve seventh and a working oil port of the damper seventh through the pressure switching valve.

The first pump oil inlet control unit comprises a three-way flow valve I, a damping I and a load sensitive LS oil path pressure limiting overflow valve;

the LS1 control oil way is communicated with the oil return port T1 through damping;

a working oil port I of the three-way flow valve is communicated with the oil inlet P1, and a working oil port II of the three-way flow valve is communicated with the oil return port T1;

an oil port I of the load-sensitive LS1 oil-way pressure-limiting overflow valve is communicated with an oil return port T1, and an oil port II of the load-sensitive LS1 oil-way pressure-limiting overflow valve is communicated with a load-sensitive oil-way pressure measuring oil port MLS 1;

and a control oil port of the first three-way flow valve is connected to a connection oil path between the load-sensitive LS1 oil path pressure-limiting overflow valve and the load-sensitive oil path pressure-measuring oil port MLS 1.

The working connection of the proportional reversing valve comprises one or the combination of any more of a telescopic reversing connection, a winch reversing connection and a variable amplitude reversing connection.

The telescopic reversing joint comprises a telescopic reversing valve and a pressure matcher II;

a first working oil port of the telescopic reversing valve is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

a control oil port of the second pressure matcher is communicated with a first working oil port and the oil inlet control linkage of the second pump;

the telescopic reversing valve is communicated with the second pressure matching valve, and the valve port pressure difference of the telescopic reversing valve is controlled through the second pressure matching valve, so that the proportional control of the telescopic reversing valve is realized.

The winch reversing joint comprises a winch reversing valve and a pressure matcher III;

a first working oil port of the winch reversing valve is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

a control oil port of the third pressure matcher is communicated with a first working oil port and a second pump oil inlet control joint;

and the winch reversing valve is communicated with the pressure matching valve III, and the valve port pressure difference of the winch reversing valve is controlled through the pressure matching valve III so as to realize the proportional control of the winch reversing valve.

The variable-amplitude reversing connection comprises a variable-amplitude reversing valve and a pressure matcher IV;

a working oil port I of the variable amplitude reversing valve is communicated with an oil inlet P1, and a working oil port II is communicated with an oil return port T1;

a control oil port of the pressure matcher IV is communicated with a working oil port I and the second pump oil inlet control link;

the variable-amplitude reversing valve is communicated with the pressure matching valve IV, and the valve port pressure difference of the variable-amplitude reversing valve is controlled through the pressure matching valve IV so as to realize the proportional control of the variable-amplitude reversing valve.

According to the invention, a first pump oil inlet control unit is connected with a first quantitative oil pump and supplies oil to a working unit of a proportional reversing valve, a second pump oil inlet control unit is connected with a second quantitative oil pump and supplies oil to a rotary reversing unit, when the rotary reversing unit does not work, the second quantitative oil pump and the first quantitative oil pump are converged through a one-way valve and a hydraulic control reversing valve of a confluence control unit, and the two pumps simultaneously supply oil to the working unit of the proportional reversing valve, so that the working efficiency is improved; when the rotary reversing union works, a hydraulic control reversing valve of the confluence control union cuts off a confluence channel of the second quantitative oil pump and the first quantitative oil pump, and the second quantitative oil pump independently supplies oil to the rotary reversing union, so that rotary action flow matching is realized, and energy consumption and system temperature rise are reduced.

A pressure switching valve matched with a one-way valve is arranged between a spring cavity control port of a three-way flow valve seventh of the second pump oil inlet control joint and a load sensitive oil path LS2 of the second oil pump system, so that the second oil pump system can realize different working pressure levels, the system is ensured to be balanced with the output power and the torque of the engine in a confluence state, and the pressure-out flameout phenomenon of the engine during working is avoided. The other function of the check valve is to prevent the hydraulic impact of the first oil pump system from being transmitted to the second oil pump, so that the second quantitative oil pump can adopt an inexpensive medium-pressure gear pump, and the manufacturing cost of the system is reduced.

Drawings

Figure 1 is a hydraulic schematic of the present invention,

figure 2 is an enlarged schematic view of region a of figure 1,

FIG. 3 is a hydraulic schematic diagram of a converging flow control coupled with a shuttle valve;

in the figure, 1 is a first pump oil inlet control joint, 11 is a three-way flow valve I, 12 is a filter, 13 is a damper, 14 is a load-sensitive LS oil way pressure-limiting overflow valve, 2 is a telescopic reversing joint, 21 is a telescopic reversing valve, 22 is a pressure matcher II, 23 is a first pressure-limiting overflow valve II, 24 is a second pressure-limiting overflow valve II, 3 is a winch reversing joint, 31 is a winch reversing valve, 32 is a pressure matcher III, 33 is a first pressure-limiting overflow valve III, 34 is a second pressure-limiting overflow valve III, 4 is a variable amplitude reversing joint, 41 is a variable amplitude reversing valve, 42 is a pressure matcher IV, 43 is a first pressure-limiting overflow valve IV, 44 is a second pressure-limiting overflow valve IV, 5 is a confluence control joint, 51 is a hydraulic control reversing valve, 52 is a damper, 53 is a shuttle valve, 6 is a rotary reversing joint, 61 is a rotary reversing valve, 62 is a pressure matcher VI, 63 is a first pressure-limiting overflow valve VI, 64 is a second pressure-limiting overflow valve VI, 7 is the second pump inlet, 71 is a one-way valve, 72 is a pressure switching valve, 73 is a damper, and 74 is a three-way flow valve seven.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As shown in fig. 1-3, in the figure, MLS1 is a load-sensitive oil line pressure measuring oil port MLS1, and MLS2 is a load-sensitive oil line pressure measuring oil port MLS 2; p1 is a first oil supply port, P2 is a second oil supply port; MP1 is the first oil pump pressure port, MP2 is the second oil pump pressure port.

A load-sensitive multi-way valve with a double-pump confluence function comprises a first pump inlet control union 1, a proportional reversing valve working union, a confluence control union 5, a rotary reversing union 6 and a second pump inlet control union 7;

the first pump oil inlet control unit 1 supplies oil to the proportional reversing valve working unit through a first quantitative oil pump;

the second oil pumping control unit 7 supplies oil to the rotary reversing unit 6 through a second quantitative oil pump;

the confluence control joint 5 is arranged between the first pump oil inlet control joint 1 and the second pump oil inlet control joint 7 and is used for controlling the confluence of the first quantitative oil pump and the second quantitative oil pump;

the confluence control union 5 comprises a hydraulic control reversing valve 51;

the mode avoids the traditional mode that the hydraulic control reversing valve 51 is controlled by taking control oil from two working oil ports A6 and B6 of the rotary reversing valve through a shuttle valve, simplifies a loop, shortens the action reaction time of the rotary reversing link 6 and improves the dynamic response performance of the rotary reversing link 6;

the rotary reversing union 6 controls the on-off of a confluence channel of the first quantitative oil pump and the second quantitative oil pump through the hydraulic control reversing valve 51, so that the second quantitative oil pump independently supplies oil to the rotary reversing union 6 when the rotary reversing union 6 is in a working state.

The confluence control unit 5 realizes the synchronous control of the on-off of the main oil paths of the two oil pumps (the first quantitative oil pump and the second quantitative oil pump) and the on-off of the load sensitive signal oil path LS1 (the dotted line connection part between the hydraulic control reversing valve 51 and the MLS1 and the residual right dotted line part is LS2 in fig. 1) and LS2 of the two oil pump systems through the hydraulic control reversing valve 51.

The working oil ports on two sides of the hydraulic control reversing valve 51 are respectively connected with the main oil passages of the first oil pump system and the second oil pump system which are arranged on two sides of the hydraulic control reversing valve in parallel, and the load sensitive signal oil passages LS1 and LS 2.

In a further expansion, the confluence control joint 5 further comprises a damper 52;

the damper 52 is arranged on a spring cavity oil return path of the hydraulic control reversing valve 51 and used for controlling the reversing action speed of a valve core of the hydraulic control reversing valve 51 and avoiding hydraulic reversing impact.

The rotary reversing joint 6 comprises a rotary reversing valve 61 and a pressure matcher six 62;

a first working oil port of the rotary reversing valve 61 is communicated with an oil inlet P1 of the first oil pumping control link 1 and an oil inlet P2 of the second oil pumping control link 7;

the working oil port of the rotary reversing valve 61 is communicated with the oil return port T1 of the first oil pump oil inlet joint 1 and the oil return port T2 of the second oil pump oil inlet control joint 7;

the other two working oil ports of the rotary reversing valve 61 are communicated with two working oil ports (a second working oil port and a third working oil port) and a second control port of the pressure matching valve 62;

two working oil ports of the hydraulic control reversing valve 51 are communicated with a first control oil port and a first working oil port of the pressure matcher 62, and the communication of the oil ports MLS1 and MLS2 is realized through the second pump oil inlet control joint 7.

The second oil pumping control joint 7 comprises a one-way valve 71, a pressure switching valve 72, a damping seven 73 and a three-way flow valve seven 74;

the oil inlet P2 supplies oil to the rotary reversing joint 6 through the one-way valve 71 and is communicated with an oil inlet of the three-way flow valve seven 74;

an oil outlet of the three-way flow valve seven 74 and the damping seven 73 are respectively communicated with an oil return port T2;

the load-sensitive oil path LS2 is communicated with the spring cavity of the three-way flow valve seven 74 and the working oil port of the damper seven 73 through the pressure switching valve 72. The three-way flow valve seven 74 is matched with the one-way valve 71 to realize the low-pressure unloading control of the second quantitative oil pump with a set pressure value; the check valve 71 of the main oil way is arranged on the second oil inlet control union 7 of the second quantitative oil pump, so that the oil port of the second quantitative oil pump can not be transmitted by the hydraulic pulse of the first oil pump system in a confluence state, and the manufacturing cost of the system can be further reduced by adopting a medium-pressure gear pump for the second quantitative oil pump.

At present, the second pump oil inlet control unit 7 generally adopts a combined mode of an overflow valve and a three-way flow valve, when the system pressure is higher than a set pressure value, the overflow valve keeps the set pressure, and the overflow valve is in an overflow state. The scheme adopts the pressure switching valve 72 and the three-way flow valve seven 74, when the system pressure is higher than the set pressure value of the pressure switching valve 72, the pressure switching valve 72 is cut off, the pressure of the control port of the three-way flow valve seven 74 is reduced to zero due to the fact that the damping 73 is communicated with T1 and T2, and the three-way flow valve seven 74 is in a low-pressure unloading state (the unloading pressure is the spring set pressure of a spring cavity and is generally only about 2MPa of standby pressure), so that not only can the energy saving performance of the system be improved, but also when the system is in a high-pressure state, the torque of an engine is reduced, and the engine is prevented from being pressed and flameout.

The first pump oil inlet control unit 1 comprises a three-way flow valve I11, a damping I13 and a load sensitive LS oil path pressure limiting overflow valve 14;

the LS1 control oil way is communicated with the oil return port T1 through a damper 13;

a first working oil port of the three-way flow valve 11 is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

an oil port I of the load-sensitive LS oil path pressure-limiting overflow valve 14 is communicated with an oil return port T1, and an oil port II of the load-sensitive LS oil path pressure-limiting overflow valve is communicated with a load-sensitive oil path pressure measuring oil port MLS 1;

and a control oil port of the three-way flow valve I11 is connected to a connection oil path between the load-sensitive LS oil path pressure-limiting overflow valve 14 and a load-sensitive oil path pressure-measuring oil port MLS 1.

Further optimized, the first oil pumping control unit 1 further comprises a filter 12 arranged between the pressure measuring oil port MLS1 of the load-sensitive oil path and the first damper 13.

The working connection of the proportional reversing valve comprises one or the combination of any more of a telescopic reversing connection 2, a winch reversing connection 3 and a variable amplitude reversing connection 4.

The telescopic reversing joint 2 comprises a telescopic reversing valve 21 and a second pressure matcher 22;

a first working oil port of the telescopic reversing valve 21 is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

the control oil port of the second pressure matcher 22 is communicated with the first working oil port through a hydraulic control reversing valve 51, the control oil port of the sixth pressure matcher 62 and the first working oil port with the control oil port of a pressure switching valve 72 of the second pump oil inlet control linkage 7;

the other two working oil ports of the telescopic reversing valve 21 are communicated with the two working oil ports of the pressure matching valve II 22 and the other control port, and the valve port pressure difference of the telescopic reversing valve 21 is controlled through the pressure matching valve II 22 so as to realize the proportional control of the telescopic reversing valve 21.

The winch reversing connection 3 comprises a winch reversing valve 31 and a pressure matcher III 32;

a first working oil port of the winch reversing valve 31 is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

the control oil port of the third pressure matcher 32 is communicated with the first working oil port through a hydraulic control reversing valve 51, the control oil port of the sixth pressure matcher 62 and the first working oil port with the control oil port of a pressure switching valve 72 of the second pump oil inlet control linkage 7;

the other two working oil ports of the winch reversing valve 31 are communicated with the two working oil ports of the third pressure matching valve 32 and the other control port, and the valve port pressure difference of the winch reversing valve 31 is controlled through the third pressure matching valve 32 so as to realize the proportional control of the winch reversing valve 31.

The variable amplitude reversing connection 4 comprises a variable amplitude reversing valve 41 and a pressure matcher IV 42;

a first working oil port of the variable amplitude reversing valve 41 is communicated with an oil inlet P1, and a second working oil port is communicated with an oil return port T1;

the control oil port of the pressure matcher IV 42 is communicated with the working oil port I through a hydraulic control reversing valve 51, the control oil port of the pressure matcher VI 62 and the working oil port I, and is communicated with the control oil port of a pressure switching valve 72 of the second pump oil inlet control unit 7;

the other two working oil ports of the variable amplitude reversing valve 41 are communicated with the two working oil ports of the pressure matching valve IV 42 and the other control port, and the valve port pressure difference of the variable amplitude reversing valve 41 is controlled through the pressure matching valve IV 42 so as to realize the proportional control of the variable amplitude reversing valve 41.

Flexible switching-over antithetical couplet 2, hoist switching-over antithetical couplet 3 and change width of cloth switching-over antithetical couplet 4 in the present case belong to prior art respectively, specifically as follows:

as shown in fig. 1, the first working oil port of the three-way flow valve 11, the first working oil port of the telescopic reversing valve 21, the first working oil port of the hoisting reversing valve 31, the first working oil port of the variable amplitude reversing valve 41, the two working oil ports of the hydraulic control reversing valve 51, the first working oil port of the rotary reversing valve 61, the two working oil ports of the check valve 71 and the first working oil port of the three-way flow valve 74 are all communicated with the oil inlet P1 of the first pump oil inlet control connection 1 and the oil inlet P2 of the second pump oil inlet connection 7;

a second working oil port of the three-way flow valve 11, a first oil port of the load-sensitive LS oil path pressure-limiting overflow valve 14, a second working oil port of the telescopic reversing valve 21, a second working oil port of the winch reversing valve 31, a second working oil port of the variable amplitude reversing valve 41, a second working oil port of the rotary reversing valve 61 and another working oil port of the three-way flow valve 74 are all communicated with an oil return port T1 and an oil return port T2;

the control port of the three-way flow valve 11, the control oil port and the working oil port I of the second pressure matcher 22, the control oil port and the working oil port I of the third pressure matcher 32, and the control oil port and the working oil port I of the fourth pressure matcher 42 are communicated with the control oil port of the pressure switching valve 72 sequentially through the hydraulic control reversing valve 51, the control oil port and the working oil port I of the sixth pressure matcher 62, and are communicated with the control port of the three-way flow valve 74 through the pressure switching valve 72, so that the communication between the oil ports MLS1 and MLS2 is realized;

the other two working oil ports of the telescopic reversing valve 21 are communicated with the two working oil ports and the other control port of the pressure matching valve 22, the other two working oil ports of the winch reversing valve 31 are communicated with the two working oil ports and the other control port of the pressure matching valve 32, the other two working oil ports of the variable amplitude reversing valve 41 are communicated with the two working oil ports and the other control port of the pressure matching valve 42, and the other two working oil ports of the rotary reversing valve 61 are communicated with the two working oil ports and the other control port of the pressure matching valve 62;

the oil port a in the rotary control union 6 is communicated with a control oil port of a pilot-controlled switching valve 51, and a spring cavity of the pilot-controlled reversing valve 51 is communicated with oil return ports T1 and T2 through a damper 52.

Further optimization, working oil ports of the reversing valves (the telescopic reversing valve 21, the winch reversing valve 31, the variable amplitude reversing valve 41, the confluence hydraulic control reversing valve 51 and the rotary reversing valve 61) of the telescopic reversing link 2, the winch reversing link 3, the variable amplitude reversing link 4 and the rotary reversing link 6, such as working oil ports of A1, B1, A2, B2, A3, B3, A4 and B4 (A1-A4 and B1-B4 in the figure are corresponding reversing link working oil ports), can be combined and selectively provided with a plurality of pressure limiting overflow valves (such as the reference numbers 23, 24, 33, 34, 43, 44, 63 and 64 in the figure 1), oil inlets of the pressure limiting overflow valves of the reversing valves are in working conduction with the corresponding reversing valves, and oil ports of the pressure limiting overflow valves are in working conduction with oil ports of the corresponding reversing valves, and oil ports of the reversing valves are in communication with oil return oil ports T1 and T2.

As shown in fig. 1, the specific working method includes the following cases:

when the crane system is in an unloaded state: any reversing link (a telescopic reversing link 2, a winch reversing link 3, a variable amplitude reversing link 4 and a rotary reversing link 6) of the proportional multi-way valve does not work, a hydraulic control reversing valve 51 of a main oil way in a confluence control link 5 is conducted due to a normally open function, hydraulic oil of a first oil pump is converged with an oil supply port P2 of a second oil pump through a first oil supply port P1, a load sensitive oil way LS1 of the first oil pump system and a load sensitive oil way LS2 of the second oil pump system are also connected in the multi-way valve, the oil way of the load sensitive oil way LS (LS is the name of the same oil way formed by the communication of the LS1 and the LS2 pipelines) has no feedback pressure, a three-way flow valve 11 and a one-way valve 71 are opened and unloaded, so that the hydraulic oil of the two oil pumps flows out of the multi-way valve through oil return ports T1 and T2 and flows back to the oil tank, and the system only keeps very low standby pressure.

When the rotary reversing connection 6 works independently and the other reversing connections do not work: pressure oil of an oil port a of the rotary reversing joint 6 enters a control cavity of a hydraulic control reversing valve 51 through a control oil path to push the hydraulic control reversing valve 51 to reverse, main oil paths of a first oil pump and a second oil pump and communicated oil paths of respective system load sensitive LS1 and LS2 oil paths are cut off, the respective systems of the first oil pump and the second oil pump are separated, and an oil supply port P2 of the second oil pump supplies oil and is independently used for the rotary reversing joint 6 to perform crane rotary operation.

When the rotary reversing connection 6 does not work, and any connection of the telescopic reversing connection 2, the winch reversing connection 3 and the amplitude-variable reversing connection 4 only needs to work: because the oil port a in the rotary reversing joint 6 can not detect a high-pressure signal, the hydraulic control reversing valve 51 in the confluence control joint 5 does not reverse and keeps a normally open function. Therefore, the hydraulic oil of the first oil pump is converged in the multi-way valve through the first oil pump oil supply port P1 and the second oil pump oil supply port P2, the load-sensitive LS1 oil line obtains the highest load pressure of the working link in the telescopic reversing link 2, the winch reversing link 3 and the variable amplitude reversing link 4, and simultaneously transmits the highest load pressure to the control oil ports of the three-way flow valve 11 and the one-way valve 71, so that the first oil pump and the second oil pump are converged and supplied with oil at the same time.

When the rotary reversing linkage 6 works and at least one of the telescopic reversing linkage 2, the winch reversing linkage 3 and the amplitude-variable reversing linkage 4 works: pressure oil of an oil port a in the rotary reversing joint 6 enters a control cavity of a hydraulic control reversing valve 51, the hydraulic control reversing valve 51 is pushed to reverse and cut off the communication of main oil paths of a first oil pump and a second oil pump and respective system load sensitive LS1 and LS2 oil paths of the two pumps, so that the respective systems of the first oil pump and the second oil pump are separated, hydraulic oil flowing out of a second oil pump oil supply port P2 is independently used for the rotary reversing joint 6 to perform crane rotary operation, and oil supplied by the first oil pump through a first oil pump oil supply port P1 is independently used for work joint operation in the telescopic reversing joint 2, the winch reversing joint 3 and the amplitude-variable reversing joint 4.

In a further development, as shown in fig. 3, the confluence control block 5 further comprises a shuttle valve 53;

an A4 oil port and a B4 oil port of the rotary proportional reversing link 6 are respectively connected with working oil ports on two sides of the shuttle valve 53;

the middle working oil port of the shuttle valve 53 is communicated with the control oil port of the hydraulic control reversing valve 51.

In fig. 3, the communication between the oil port a of the pressure matcher 62 and the control oil port of the pilot-controlled reversing valve 51 is eliminated; the working oil ports A4 and B4 of the rotary proportional reversing linkage supplied by the second oil pump system are respectively led out of control oil paths and connected to the working oil ports on the two sides of the shuttle valve 53, and the middle working oil port of the shuttle valve 53 is communicated with the control oil port of the hydraulic control reversing valve 51.

When the rotary reversing linkage 6 works and at least one of the telescopic reversing linkage 2, the winch reversing linkage 3 and the amplitude-variable reversing linkage 4 works: the pressure of the oil port A4 and the oil port B4 of the rotary reversing linkage 6 enters the oil ports on the two sides of the shuttle valve 53 through control oil paths, and the shuttle valve 53 selects the oil path with high pressure in the oil port A4 and the oil port B4 and is communicated with the control oil port of the hydraulic control reversing valve 51 through the middle oil port of the shuttle valve 53. As long as the rotary reversing link 6 works, a pressure signal with high pressure in the oil ports A4 and B4 enters a control cavity of the hydraulic control reversing valve 51 through the shuttle valve 53 to push the hydraulic control reversing valve 51 to reverse and cut off a main oil path of the first oil pump and the second oil pump and a communicated oil path of a load sensitive LS oil path of each system of the first oil pump and the second oil pump, so that each system of the first oil pump and the second oil pump is separated, an oil supply port P2 of the second oil pump supplies oil and is independently used for the rotary reversing link 6 to perform the rotary operation of the crane, and an oil supply port P1 of the first oil pump supplies oil and is independently used for the working link operation in the telescopic reversing link 2, the winch reversing link 3 and the amplitude-variable reversing link 4.

The oil inlet of the first oil pump is connected with the 1, the pressure limiting of a main oil path is realized by adopting a load sensitive LS oil path pressure limiting overflow valve 14 to pilot control a three-way flow valve 11, and the pressure limiting of the main oil path is generally set to be high (for example, the oil supply port P1 = 30 MPa) so as to meet the requirement of high load pressure of a telescopic reversing connection 2, a winch reversing connection 3 and a variable amplitude reversing connection 4; a load sensitive LS2 oil path from the rotary reversing linkage 6, a pressure switching valve 72 with a normally open function is connected with a control port of a three-way flow valve 74, a control cavity of the pressure switching valve 72 is also directly connected with a load sensitive LS2 oil path from the rotary reversing linkage 6, and the set pressure value of the pressure switching valve 72 is generally lower (for example, a second oil pump oil supply port P2 = 16 MPa); when the pressure of the oil line of the load-sensitive LS2 from the rotary reversing link 6 is not higher than a set value, the pressure switching valve 72 directly acts on a control port of the three-way flow valve 74, and at the moment, the three-way flow valve 74 enables the second pump system to generate working pressure corresponding to the load-sensitive LS 2; when the pressure of the oil line of the load-sensitive LS2 from the rotary reversing joint 6 is higher than the set value of the pressure switching valve 72, the pressure switching valve 72 is closed, the control cavity of the three-way flow valve 74 is opened through the pressure relief of the damper 73, and the low-pressure unloading of the P2 pump port of the second pump system is achieved.

The working pressure of the rotary reversing coupling 6 is generally set to be low (for example, the oil supply port P2 = 16MPa of the second oil pump), and the actual working pressure requirement of the rotary reversing coupling 6 can be met. When the rotary union works, the hydraulic control reversing valve 51 of the confluence control valve 5 reverses, the communication between the first oil pump oil supply port P1 and the second oil pump oil supply port P2 is cut off, the load-sensitive LS1 oil path and the load-sensitive LS2 oil path is cut off, and the load pressure of the rotary union 6 is fed back by the load-sensitive LS2 oil path; when the rotary reversing link 6 does not work and the hydraulic control reversing valve 52 does not reverse, the feedback is the load pressure of other links except the rotary reversing link 6, and the three-way flow valve 74 is also controlled by the pilot pressure limiting of the pilot overflow valve 14 of the load-sensitive LS1 oil path on the first oil pump oil inlet link 1 in the multi-path valve confluence state, namely the pressure limiting set pressure of the three-way flow valve 71 is the same as the pressure limiting set pressure of the three-way flow valve 11. When the rotary reversing joint 6 does not work and the multi-way valve is in a confluence state, the pressures of the first oil pump port P1 and the second oil pump port P2 rise along with the increase of the load, when the load pressure rises to the set pressure (such as 16 MPa) of the pressure switching valve 52 of the oil inlet joint 7, the pressure switching valve 52 is closed, the second oil pump oil supply port P2 is unloaded at low pressure under the action of the three-way flow valve 74, and at the moment, the one-way valve 71 is stopped, so that the first oil pump system continues to normally work without being influenced by the unloading of the second oil pump system. The pressure of the second oil pump independent supply rotary reversing coupling 6 is very low, so that the torque taken by the second oil pump independent supply rotary reversing coupling to the chassis engine can not rise along with the lifting of the working load of the first oil pump system any more, and the effect is that when the first oil pump system works under a high load, the total output torque demand of the engine is restrained, so that the phenomenon that the engine is suppressed and stalled is avoided.

The disclosure of the present application also includes the following points:

(1) the drawings of the embodiments disclosed herein only relate to the structures related to the embodiments disclosed herein, and other structures can refer to general designs;

(2) in case of conflict, the embodiments and features of the embodiments disclosed in this application can be combined with each other to arrive at new embodiments;

the above embodiments are only embodiments disclosed in the present disclosure, but the scope of the disclosure is not limited thereto, and the scope of the disclosure should be determined by the scope of the claims.