CN112797046A

CN112797046A - Load feedback control loop and load sensitive quantitative system

Info

Publication number: CN112797046A
Application number: CN202110369610.9A
Authority: CN
Inventors: 徐晶晶; 李之雄; 周敏; 侯召军
Original assignee: Hunan Sky Hydraulics Science And Technology Co ltd
Current assignee: Hunan Sky Hydraulics Science And Technology Co ltd
Priority date: 2021-04-07
Filing date: 2021-04-07
Publication date: 2021-05-14

Abstract

The invention provides a load feedback control loop and a load sensitive quantitative system, wherein the load feedback control loop comprises a first restrictor, a first directional valve, a second restrictor, a feedback control unit and an actuator; the load feedback control loop is provided with a loop oil inlet, a loop oil return port and a feedback pressure oil output port; the first directional valve comprises a first oil inlet, a first oil return port, a first working port and a second working port; the feedback control unit comprises a logic valve, and the logic valve comprises a first input port, a second input port and a first output port; the actuator comprises a first load port and a second load port; the loop oil inlet, the first throttler and the first oil inlet are sequentially connected in series, and the loop oil return port is communicated with the first oil return port; the first working port is communicated with the first load port, and the second working port, the second throttler and the second load port are sequentially connected in series; the first input port is communicated with the first load port, the second input port is communicated with the second load port, and the first output port is communicated with the feedback pressure oil output port.

Description

Load feedback control loop and load sensitive quantitative system

Technical Field

The invention relates to the field of fluid transmission and control, in particular to a load feedback control loop and a load sensitive quantitative system.

Background

The hydraulic transmission has the advantages of high power density, large arrangement flexibility, easy load maintenance, convenient linear high-power reciprocating motion realization and the like, and is widely applied to the fields of engineering machinery, maritime work, ships, mines, agricultural machinery, industry, aerospace and the like. The load sensitive control is a high-end control technology in hydraulic transmission, can realize the allocation of loop pressure and flow according to the control requirement of a loop, and can realize multi-action compound motion control through a loop differential pressure compensation technology, thereby being a high-efficiency power source allocation control technology. The core vectors of the technology are load-sensitive valves and load-sensitive quantitative systems. The domestic and foreign famous hydraulic parts manufacturers develop a load-sensitive multi-way valve with complete specification series and a load-sensitive quantitative system. However, the load-sensitive multi-way valve has advanced technology, complex structure, weak element universality and high application cost, which also becomes an important factor restricting the wide application of the load-sensitive technology. Therefore, it is an urgent need to develop a more economical load-sensitive control technology to promote the wide application of the high-efficiency load-sensitive control technology.

Disclosure of Invention

In view of the defects in the prior art, the present invention provides a load feedback control loop and a load sensitive quantitative system.

The load feedback control loop comprises a first throttle, a first directional valve, a second throttle, a feedback control unit and an actuator; the load feedback control loop is provided with a loop oil inlet, a loop oil return port and a feedback pressure oil output port; the first directional valve comprises a first oil inlet, a first oil return port, a first working port and a second working port; the feedback control unit comprises a logic valve, and the logic valve comprises a first input port, a second input port and a first output port;

the actuator comprises a first load port and a second load port; the loop oil inlet, the first throttler and the first oil inlet are sequentially connected in series, and the loop oil return port is communicated with the first oil return port;

the first working port is communicated with the first load port, and the second working port, the second throttler and the second load port are sequentially connected in series;

the first input port is communicated with the first load port, the second input port is communicated with the second load port, and the first output port is communicated with the feedback pressure oil output port.

Preferably, the feedback control unit further comprises a first relief valve and a second relief valve; or the feedback control unit comprises any one of a first overflow valve, a second overflow valve and a third overflow valve;

the first overflow valve is communicated with the first input port and the return oil port of the loop;

the second overflow valve is communicated with the second input port and the return oil port of the loop;

and the third overflow valve is communicated with the first output port and the return oil port.

Preferably, the feedback control unit further comprises a fourth relief valve and a fifth relief valve;

the fourth overflow valve is communicated with the first input port and the return oil port of the loop;

and the fifth overflow valve is communicated with the second input port and the return oil port of the return circuit.

Preferably, the feedback control unit further comprises a crossover relief valve, one end of the crossover relief valve is communicated with the first input port, and the other end of the crossover relief valve is communicated with the second input port.

Preferably, the actuator further comprises a third control oil port, and the feedback pressure oil output port is communicated with the third control oil port.

The invention also provides a load sensitive quantitative system, which comprises the load feedback control loop, an oil source control unit and a power unit;

the oil source control unit comprises a first feedback pressure input port, a pressure oil inlet and a pressure oil outlet;

the power unit comprises a pressure oil output port and a pressure oil return port;

the pressure oil output port is respectively communicated with the pressure oil inlet and the loop oil inlet;

the pressure oil return port is respectively communicated with the pressure oil outlet and the return circuit oil return port;

the first feedback pressure input port is communicated with the feedback pressure oil output port.

Preferably, the oil source control unit further includes a sixth relief valve and a seventh relief valve;

the sixth overflow valve is communicated with the first feedback pressure input port and the pressure oil outlet;

the seventh overflow valve is communicated with the pressure oil inlet and the pressure oil outlet, and the seventh overflow valve further comprises a feedback port communicated with the first feedback pressure input port.

Preferably, the oil source control unit further includes an eighth relief valve that communicates the pressure oil inlet and the pressure oil outlet.

Preferably, the oil source control unit further comprises a second directional valve communicating the first feedback pressure input port and the pressure oil outlet port.

Preferably, the load-sensitive quantifying system further comprises a feedback logic module and a plurality of load feedback control loops;

the feedback logic module comprises a feedback oil output port and a plurality of feedback oil input ports, and the feedback oil input ports are communicated with the feedback pressure oil output ports in a one-to-one correspondence manner;

the feedback oil output port is in communication with the first feedback pressure input port.

The invention has the technical effects that:

the invention provides a load feedback control loop and a load sensitive quantitative system, which can realize the allocation of loop pressure and flow according to the control requirement of the loop and can realize multi-action compound motion control through the loop differential pressure compensation technology. And the load feedback control loop has a simple structure, two different loop flows can be obtained by setting and adjusting the opening degrees of the first restrictor and the second restrictor, and the asymmetric flow control of the loop is realized. In a traditional oil inlet or oil return throttling speed regulation loop, most of pressure is lost on a throttling element, so that effective pressure difference distributed by an actuator is small, and the driving force of the loop is greatly reduced. The load feedback control loop provided by the invention can be simplified to realize the constant-ratio and constant-speed control of the asymmetric flow control loop through 2 fixed dampers by skillfully combining and configuring the first throttler and the second throttler in the loop, and the required distribution of the loop pressure flow is realized by combining the oil source pressure flow control based on load feedback, and the loop has large driving force and high system efficiency under the same pressure condition.

Drawings

FIG. 1 is a schematic diagram of a load feedback control loop according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a feedback control unit in the embodiment of FIG. 1;

FIG. 3 is a schematic structural diagram of another embodiment of the feedback control unit in the embodiment of FIG. 1;

FIG. 4 is a schematic structural diagram of another embodiment of a load feedback control loop according to the present invention;

FIG. 5 is a schematic structural diagram of a feedback control unit in the embodiment of FIG. 4;

FIG. 6 is a schematic structural diagram of another embodiment of the feedback control unit in the embodiment of FIG. 4;

FIG. 7 is a schematic structural diagram of another embodiment of the feedback control unit in the embodiment of FIG. 4;

FIG. 8 is a schematic structural diagram of another embodiment of the feedback control unit in the embodiment of FIG. 4;

FIG. 9 is a schematic structural diagram of another embodiment of a load feedback control loop in accordance with the present invention;

FIG. 10 is a schematic structural diagram of a load feedback control loop in accordance with another embodiment of the present invention;

FIG. 11 is a schematic diagram of an embodiment of a load sensitive quantification system of the present invention;

FIG. 12 is a schematic structural diagram of another embodiment of the oil source control unit in the embodiment of FIG. 11;

FIG. 13 is a schematic structural diagram of an oil source control unit in the embodiment of FIG. 11;

FIG. 14 is a schematic structural diagram of another embodiment of the load-sensitive quantification system of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1:

referring to fig. 1 to 3, the present invention proposes a load feedback control loop including a first choke 11, a first directional valve 12, a second choke 13, a feedback control unit 14, and an actuator 15; the load feedback control loop is provided with a loop oil inlet P1, a loop oil return port T1 and a feedback pressure oil output port LS 1; the first directional valve comprises a first oil inlet P12.3, a first oil return port P12.1, a first working port P12.2 and a second working port P12.4; the feedback control unit comprises a logic valve 141 comprising a first input port P141.1, a second input port P141.2 and a first output port P141.3; the actuator includes a first load port A1 and a second load port B1; the loop oil inlet P1, the first throttle 11 and the first oil inlet P12.3 are sequentially connected in series, and the loop oil return port T1 is communicated with the first oil return port P12.1; the first working port P12.2 is communicated with the first load port A1, and the second working port P12.4, the second throttling device 13 and the second load port B1 are sequentially connected in series; the first input port P141.1 communicates with the first load port a1, the second input port P141.2 communicates with the second load port B1, and the first output port P141.3 communicates with the feedback pressure oil output port LS 1.

The feedback control unit 14 includes three ports, P14.1, P14.2 and P14.3, with P14.1 communicating with the first load port a1, P14.2 communicating with the second load port B1, and P14.3 communicating with the feedback pressure output port LS 1. The feedback control unit 14 includes a logic valve 141; wherein the first inlet port P141.1 communicates with P14.1; the second input ports P141.2 are communicated with 14.2, and the first output ports P141.3 are communicated with P14.3; the communication described in the present invention can be understood as directly connecting two oil ports through a pipeline.

The oil path flow of the present embodiment is as follows: when the first directional valve 12 is in the left position, the pressure oil flows in from the loop oil inlet P1, passes through the first choke 11 and the first directional valve 12 once, then flows from the second working port P12.4 of the first directional valve 12 to the second choke 13, passes through the second choke 13, reaches the second load port B1, and simultaneously the pressure of the second load port B1 is also communicated with the port P14.2 of the feedback control unit 14, the return oil of the actuator passes through the first load port a1, reaches the first working port P12.2, passes through the first directional valve 12, returns to the loop oil return port T1 from the first return port P12.1, and simultaneously the pressure of the first load port a1 is transmitted to the port P14.1 of the feedback control unit 14, and then the pressure oil at the ports P14.1 and P14.2 respectively reaches the first input port P141.1 and the second input port P141.2 of the logic valve 141, and since the pressure at the port P14.2 is higher than the pressure at the port P14.1, the output port P14.3 controls the output port P3.3 and the output port P14.2 of the logic valve 141.3, the output port P14.2, the output port P14 is higher pressure of the logic valve 14, which is higher than the pressure And then to the loop feedback pressure output port LS 1. It follows that the feedback pressure in this state is taken to be the load pressure after passing through the first and

second restrictions

11, 13;

when the first directional valve 12 is at the right position, the pressure oil flows in from the circuit oil inlet P1, passes through the first choke 11 and the first directional valve 12 once, then flows from the first working port P12.2 of the first directional valve 12 to the first load port a1 of the actuator, at the same time, the pressure of the first load port a1 is also communicated to the port P14.1 of the feedback control unit 14, the return oil of the actuator reaches the second working port P12.4 of the first directional valve 12 through the second load port B1 and the second choke 13, passes through the first directional valve 12 and then returns to the circuit oil return port T1 from the first return port P12.1, at the same time, the pressure of the second load port B1 is also communicated to the port P14.2 of the feedback control unit 14, then, the pressure oil at the ports P14.1 and P14.2 of the feedback control unit 14 respectively reaches the first and second input ports P141.1 and P141.2 of the logic valve 141, because the pressure of the port P14.1 is higher than the pressure of the port P14.2, the logic valve 141, and the two ports are compared, and the pressure oil of the higher oil port P14.1 is output to the oil port P14.3 of the feedback control unit 14 through the oil port P141.3 and then to the loop feedback pressure output port LS 1. It can be seen that the feedback pressure in this state is taken to be the load pressure after passing through the first throttle 11.

In the present embodiment, the first choke 11 may be in the form of any one of a fixed orifice, an adjustable choke, and an adjustable band compensation choke; the second restrictor 13 may be in the form of any one of a fixed orifice, a one-way restrictor, an adjustable restrictor, a one-way adjustable restrictor, an adjustable band-compensated restrictor, and an adjustable band-compensated one-way restrictor. The logic valve 141 in the feedback control unit 14 may be a single spool shuttle valve or a double spool shuttle valve, or may be an integrated valve formed of a double one-way valve.

The load feedback control loop has the following beneficial effects: the flow rate of P1-A1 can be adjusted to meet the speed control requirement of a first load port A1 by setting or adjusting the opening degree of the first throttling device 11, and then the flow rate of P1-B1 can be adjusted to meet the speed control requirement of a first load port A1 load by setting or adjusting the opening degree of the second throttling device 13, and the flow rate of P-B1 is less than or equal to the flow rate of P-A1 because the flow rate of P-A1 is determined by the opening degree of the first throttling device 11 and the system pressure difference, and the flow rate of P-B1 is determined by the series opening degree of the first throttling device 11 and the second throttling device 13 and the system pressure difference. It can be seen that the load feedback control loop can obtain two different loop flow rates by setting and adjusting the opening degrees of the first choke 11 and the second choke 13, and thus realizes the asymmetric flow rate control of the loop. When the first throttle device 11 and the second throttle device 13 are embodied as fixed damping holes, the load feedback control loop achieves the purpose of achieving an asymmetric flow control loop in a load feedback control system by using two fixed damping instead of two throttling elements, so that the loop control elements are simplified, the manufacturing cost is reduced, and the load feedback control loop has important practical value.

Example 2:

referring to fig. 3 and 7, the feedback control unit 14 further includes a crossover relief valve 142, and one end P142.1 of the crossover relief valve 142 communicates with the first input port P141.1, and the other end P142.2 communicates with the second input port P141.2. In this embodiment, the cross relief valve 142 includes two relief valves connected in parallel in opposite directions, and an input port of one relief valve is connected end to end with an output port of the other relief valve, and the two relief valves share the pressure adjusting device, and the effective areas of the two ports of the cross relief valve for input and output are equal to each other on the valve core. The feedback control unit 14 has the following effects by arranging the cross relief valve 142: by adjusting the relief pressure of cross-over relief valve 142, the control requirement of the same maximum operating pressure of the two load ports a1 and B1 in the circuit is controlled with only one element. The control elements are reduced, the loop control is simplified, the loop control cost is reduced, and the method has important application value in the symmetrical flow loop with the same pressure limit requirement of the two oil ports.

Example 3:

referring to fig. 4 to 6, the feedback control unit includes any one of a first relief valve 143, a second relief valve 144, and a third relief valve 145, or the feedback control unit includes the first relief valve 143 and the second relief valve 144;

specifically, the first relief valve 143 communicates the first input port P141.1 and the return port T1; the second spill valve 144 communicates between the second input port P141.2 and the return line T1. The third relief valve 145 communicates the first output port P141.3 and the return port T1.

The description in this paragraph includes four scenarios; in the first scheme, the feedback control unit only comprises the first overflow valve 143; in the second scheme, the feedback control unit only comprises the second overflow valve 144; in a third scheme, the feedback control unit only comprises a third overflow valve 145; in a fourth scheme, the feedback control unit comprises a first overflow valve 143 and a second overflow valve 144; fig. 5 corresponds to scheme four, and reference is also made to fig. 5 and 6 for three other schemes.

Example 4:

referring to fig. 7, the feedback control unit further includes a fourth relief valve 146 and/or a fifth relief valve 147; the fourth spill valve 146 communicates the first inlet port P141.1 with the return circuit port T1; the fifth spill valve 147 communicates between the second supply port P141.2 and the return port T1.

Referring to fig. 8, the first, second, third, fourth, and

fifth relief valves

143, 144, 145, 146, and 147 coexist to form a redundant solution.

The beneficial effects obtained by each overflow valve configured by the feedback control unit 14 are as follows:

the first relief valve 143 defines the feedback pressure of the first load port a1, the second relief valve 144 defines the feedback pressure of the second load port B1, and the third relief valve 145 similarly defines the feedback pressures of the first load port a1 and the second load port B1, so that the feedback pressure is defined by a low-flow relief valve, and the circuit load port pressure is defined by an oil source module.

The fourth spill valve 146 directly limits the pressure at the first load port a 1; fifth spill valve 147 directly limits the pressure at second load port B1; when the fourth overflow valve 146 is an oil supplementing overflow valve, and when the first load port a1 has an air suction tendency under the action of a negative load, the oil supplementing check valve of the fourth overflow valve 146 is opened, and oil flows from the oil port 14.4 to the first load port a1 through the fourth overflow valve 146, so that oil supplementation of the first load port a1 is realized, and damage to system elements caused by air suction is prevented; when the fifth relief valve 147 is an oil-replenishing relief valve, and when the second load port B1 has a suction tendency under the action of a negative load, the oil-replenishing check valve of the fifth relief valve 147 is opened, and the oil flows from the oil port 14.4 to the second load port B1 through the fourth relief valve 146, so that the oil is replenished to the second load port B1, and damage to system elements due to suction is prevented.

Example 5:

with reference to fig. 9 and 10, the actuator also has a third control port Pi1, Pi1 communicating with port P14.3 of the feedback control unit; the practical typical application scenarios are as follows: in a rotary driving circuit with rotary supporting equipment, such as a pump truck, a crane and the like, a pressure signal related to driving pressure is needed to start a brake on a rotary motor or a rotary speed reducer during rotary motion; in the loop control of a hydraulic winch, a crane winch and the like, a driving pressure related pressure signal is also needed to start a brake on a rotary motor or a rotary speed reducer when an actuator acts; in a belt pressure dependent two-speed switching travel motor control circuit, a pressure dependent dynamic pressure signal is also required to control the automatic two-speed switching of the motor.

Example 6:

referring to fig. 11, the present invention further provides a load-sensitive quantitative system, which includes the load feedback control loop, the oil source control unit SC, and the power unit PU; the source control unit SC includes a first feedback pressure input port LS0, a pressure oil inlet port P0, and a pressure oil outlet port T0; the power unit PU comprises a pressure oil output port P and a pressure oil return port T; the pressure oil outlet P is respectively communicated with a pressure oil inlet P0 and a loop oil inlet P1; the pressure oil return port T is respectively communicated with a pressure oil outlet T0 and a return circuit oil return port T1; the first feedback pressure input port LS0 communicates with the feedback pressure oil output port LS 1.

Example 7:

referring to fig. 11 to 13, the oil source control unit SC further includes a sixth relief valve SC1 and a seventh relief valve SC 2; the sixth relief valve SC1 communicates the first feedback pressure input port LS0 and the pressure oil outlet port T0; the seventh relief valve SC2 communicates the pressure oil inlet P0 and the pressure oil outlet T0, and the seventh relief valve SC2 further includes a feedback port that communicates with the first feedback pressure input port LS 0. The oil source control unit SC further includes an eighth relief valve SC1, the eighth relief valve SC3 communicating the pressure oil inlet P0 and the pressure oil outlet T0. The source control unit SC also includes a second directional valve SC4 communicating the first feedback pressure input port LS0 and the pressure oil outlet port T0.

The oil source control unit SC is provided with a relief valve SC1, the maximum value of the feedback pressure is adjusted and limited, and the feedback pressure limited by the sixth relief valve SC1 is transmitted to a feedback port PSC2.3 of a seventh relief valve SC2 (on an inner valve core of the seventh relief valve SC2, the action area of the PSC2.1 port pressure is equal to the action area of the PSC2.3 port pressure), so that the pressure of the SC2 port is limited to a value which is higher than the PSC2.3 port pressure by one spring pressure (namely, when the PSC2.3 feedback value is 0, the opening pressure of the seventh relief valve SC2 under the action of the PSC2.1 port pressure), and the required distribution of the system pressure is realized.

The oil source control unit SC is provided with an eighth overflow valve SC3, the pressure of a P0 port is directly limited, and the system is protected by full-weight pressure safety; the oil source control unit SC is provided with a second directional valve SC4, so that on-off control of the feedback cavity to the 0 pressure cavity (usually an oil tank) is realized, pressure build and pressure relief control is performed on the system, and the system can be used for enabling control of system action.

Example 8:

referring to fig. 14, the load-sensitive quantification system further includes a feedback logic module LFLB and a plurality of load feedback control loops; the feedback logic module LFLB comprises a feedback oil output port LF and a plurality of feedback oil input ports LI1, and the feedback oil input ports LI1 are communicated with the feedback pressure oil output ports LS1 in a one-to-one correspondence mode; the feedback oil outlet LF communicates with the first feedback pressure inlet LS 0. The feedback oil pressure output by the feedback oil output port LF is equal to the path with the largest oil pressure in each feedback oil input port.

The load sensitive quantitative system adopts system pressure control based on load feedback, so that the system pressure is distributed as required, and redundant flow overflows from the three-way overflow valve by load pressure, so that the efficiency is higher than that of the traditional overflow system, and the energy is saved.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements.

The foregoing is a more detailed description of the present invention that is presented in conjunction with specific embodiments, and the practice of the invention is not to be considered limited to those descriptions. It will be apparent to those skilled in the art that a number of simple derivations or substitutions can be made without departing from the inventive concept.

Claims

1. A load feedback control loop is characterized by comprising a first throttle, a first directional valve, a second throttle, a feedback control unit and an actuator;

the load feedback control loop is provided with a loop oil inlet, a loop oil return port and a feedback pressure oil output port;

the first directional valve comprises a first oil inlet, a first oil return port, a first working port and a second working port;

the feedback control unit comprises a logic valve, and the logic valve comprises a first input port, a second input port and a first output port;

the actuator comprises a first load port and a second load port;

the loop oil inlet, the first throttler and the first oil inlet are sequentially connected in series, and the loop oil return port is communicated with the first oil return port;

2. The load feedback control loop of claim 1, wherein said feedback control unit further comprises a first relief valve and a second relief valve; or the feedback control unit comprises any one of a first overflow valve, a second overflow valve and a third overflow valve;

3. The load feedback control loop of claim 1, wherein the feedback control unit further comprises a fourth relief valve and a fifth relief valve;

4. A load feedback control loop according to claim 1, wherein said feedback control unit further comprises a crossover relief valve, one end of said crossover relief valve communicating with the first input port and the other end communicating with the second input port.

5. The load feedback control loop of claim 1, wherein said actuator further comprises a third control port, and a feedback pressure oil output port is in communication with said third control port.

6. A load sensitive dosing system comprising a load feedback control loop according to any of claims 1-5, an oil source control unit and a power unit;

7. The load sensitive quantification system of claim 6, wherein the oil source control unit further comprises a sixth relief valve and a seventh relief valve;

8. The load sensitive quantifying system of claim 7, wherein the oil source control unit further comprises an eighth relief valve communicating the pressure oil inlet and the pressure oil outlet.

9. The load sensitive dosing system of claim 8, wherein the oil source control unit further comprises a second directional valve communicating the first feedback pressure input port and the pressure oil outlet port.

10. The load sensitive quantifying system of claim 6, further comprising a feedback logic module and a plurality of load feedback control loops;