Flow distribution system for excavator with multiple actuators and excavator

Abstract

This invention discloses a flow distribution system and excavator suitable for excavators with multiple actuators. The system includes a pump unit, several flow distribution units, and a controller. A temperature and pressure sensor is installed at the outlet of the pump unit. Each flow distribution unit includes a first proportional valve and a second proportional valve, whose inlets are respectively connected to the pump unit. Port A of the first proportional valve and port B of the second proportional valve are respectively connected to the inlet and outlet ports of the corresponding actuators. Temperature and pressure sensors are installed at ports A and B of the first and second proportional valves, respectively. The controller calculates control signals for the pump unit, the first proportional valve, and the second proportional valve based on acquired engine speed, relevant parameters of the pump unit, handle signals, and output signals from the temperature and pressure sensors. The controller then controls the pump unit, the first proportional valve, and the second proportional valve according to these control signals. This invention enables precise flow distribution and coordinated control of the pump and valves.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a flow distribution system and an excavator suitable for excavators with multiple actuators. Background Technology

[0002] Currently, traditional excavator hydraulic systems are mostly positive flow systems, negative flow systems, and load-sensitive systems. In these systems, the oil inlet and outlet of the actuators are controlled by a single valve core coupling, resulting in simultaneous throttling control of the inlet and outlet, generating significant throttling losses. Furthermore, to achieve proper flow distribution, the dimensional parameters of each throttling groove need to be meticulously calculated, requiring extensive testing or simulation to optimize these parameters—a highly complex process. In addition, the complex valve core structure presents significant challenges to the manufacturing process. In engineering practice, extreme temperature conditions can lead to uncoordinated flow distribution among the excavator's actuators, reducing overall machine maneuverability. Temperature, as a key factor affecting hydraulic oil viscosity, significantly influences pump leakage and valve flow, thus affecting precise flow matching.

[0003] Currently, there are two methods for flow distribution in excavators: proportional distribution and cascade distribution. Proportional distribution is more commonly used in traditional excavator applications with positive flow, negative flow, and load sensitivity, while flow distribution methods for independent valve systems are relatively rare. Proportional distribution allocates flow proportionally to the ratio of demand flow to maximum flow when the flow is saturated. Cascade distribution, on the other hand, allocates flow according to priority, first satisfying the actuators with higher priority, and then distributing flow sequentially level by level when the flow is saturated.

[0004] Existing traffic allocation methods have the following drawbacks:

[0005] Traditional excavator hydraulic systems use actuators with inlet and outlet oil control coupling. At the same time, throttling generates a large amount of throttling losses. In order to distribute the flow reasonably, the size of the throttling groove needs to be precisely designed, which greatly increases the difficulty of the design and manufacturing stages.

[0006] The effect of temperature on flow rate is not considered. Temperature affects the viscosity of hydraulic oil, which in turn affects the pump leakage and the flow rate in the system, ultimately affecting the accurate distribution of flow. Especially in low-temperature environments, this can greatly reduce the overall machine operability. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a flow distribution system and excavator suitable for excavators with multiple actuators, which can achieve precise flow distribution and coordinated control of pumps and valves.

[0008] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0009] In a first aspect, the present invention provides a flow distribution system suitable for excavators with multiple actuators, comprising:

[0010] The pump unit is equipped with a temperature and pressure sensor at its outlet.

[0011] Several flow distribution units, each flow distribution unit includes an independently set first proportional valve and second proportional valve, the oil inlet of the two valves are respectively connected to the pump unit, the A port of the first proportional valve and the B port of the second proportional valve are respectively used to connect to the oil inlet and outlet ports of the corresponding actuators, and temperature and pressure sensors are respectively provided at the A port of the first proportional valve and the B port of the second proportional valve.

[0012] The controller has its input terminals connected to each temperature and pressure sensor, and its output terminals connected to the pump unit and the first and second proportional valves in each flow distribution unit. Based on the acquired engine speed, oil parameters, relevant parameters of the pump unit, handle signal, and output signals of each temperature and pressure sensor, the controller calculates the control signals for the pump unit, the first proportional valve, and the second proportional valve, and controls the pump unit, the first proportional valve, and the second proportional valve according to the control signals to realize the flow distribution of multiple actuators.

[0013] Optionally, the pump unit includes a first pump and a second pump arranged coaxially, and both the first pump and the second pump are equipped with temperature and pressure sensors at their outlets.

[0014] Optionally, the number of the flow distribution units is four, which are respectively referred to as the first flow distribution unit, the second flow distribution unit, the third flow distribution unit, and the fourth flow distribution unit;

[0015] The A port of the first proportional valve and the B port of the second proportional valve in the first flow distribution unit are respectively used to connect to the rodless chamber and the rod chamber of the boom cylinder.

[0016] The A port of the first proportional valve and the B port of the second proportional valve in the second flow distribution unit are respectively used to connect to the rodless chamber and the rod chamber of the bucket cylinder.

[0017] The A port of the first proportional valve and the B port of the second proportional valve in the third flow distribution unit are respectively used to connect to the rodless chamber and the rod chamber of the boom cylinder.

[0018] The A port of the first proportional valve and the B port of the second proportional valve in the fourth flow distribution unit are respectively used to connect to the inlet and outlet oil ports of the rotary motor.

[0019] The oil inlets of the first flow distribution unit and the second flow distribution unit are respectively connected to the oil outlet of the first pump;

[0020] The oil inlets of the third and fourth flow distribution units are respectively connected to the oil outlet of the second pump.

[0021] Optionally, the controller calculates the maximum theoretical flow rate and theoretical leakage of the first and second pumps based on the obtained engine speed, oil parameters, relevant parameters of the first and second pumps, and outlet pressure of the first and second pumps, and then obtains the maximum outlet flow rate of the first and second pumps.

[0022] The controller determines the target rotational speed of each actuator based on the handle signal and calculates the required flow rate of each actuator, thereby obtaining the total required flow rate of the first pump and the second pump.

[0023] Based on the total required flow rate of the first and second pumps, and the maximum outlet flow rate of the first and second pumps, the control signals for the first pump, the second pump, and the first and second proportional valves connected to each actuator are calculated.

[0024] Optionally, the maximum outlet flow rate of the first pump is calculated using the following formula:

[0025] q out1 =q l1 -q x1

[0026]

[0027] q l1 =nV max1

[0028] The maximum outlet flow rate of the second pump is calculated using the following formula:

[0029] q out2 =q l2 -q x2

[0030]

[0031] q l2 =nV max2

[0032] Where, q out1 and q out2 q represents the maximum outlet flow rate of the first pump and the maximum outlet flow rate of the second pump, respectively. l1 and q l2 q represents the maximum theoretical flow rate of the first pump and the maximum theoretical flow rate of the second pump, respectively. x1 and q x2 P represents the theoretical leakage of the first pump and the theoretical leakage of the second pump, respectively. d1 and P d2K1 and K2 represent the outlet pressures of the first and second pumps, respectively, and the structural parameters of the first and second pumps, respectively. max1 and V max2 These represent the maximum displacement of the first pump and the maximum displacement of the second pump, respectively. n represents the engine speed, ν represents the kinematic viscosity of the oil, and ρ represents the oil density.

[0033] Optionally, the total required flow rate of the first pump is calculated using the following formula:

[0034] Q1 = q boom +q bucket

[0035] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q boom =0,q bucket =0;

[0036] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q boom =v sboom (A boom1 -A boom2 ), q bucket =v sbucket (A bucket1 -A bucket2 ),

[0037] When the load force of the hydraulic cylinder and the displacement of the hydraulic cylinder are not in the same direction, q boom =A boom ×v sboom q bucket =A bucket ×v sbucket ;

[0038] The total required flow rate of the second pump is calculated using the following formula:

[0039] Q2 = q arm +q swing

[0040] q swing =n m ×V m

[0041]

[0042] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q arm =0;

[0043] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q arm =vsarm (A arm1 -A arm2 ),

[0044] When the load force of the hydraulic cylinder and the displacement of the hydraulic cylinder are not in the same direction, q arm =A arm ×v sarm ;

[0045] Where Q1 and Q2 represent the total demand flow rates of the first pump and the second pump, respectively, q boom q bucket q arm q swing A represents the required flow rates of the boom cylinder, bucket cylinder, stick cylinder, and swing motor, respectively. boom A bucket A arm A represents the working chamber area of ​​the boom cylinder, bucket cylinder, and stick cylinder, respectively. boom1 A boom2 A represents the rodless chamber working area and the rod chamber working area of ​​the boom cylinder, respectively. bucket1 A bucket2 Let A represent the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the bucket cylinder, respectively. arm1 A arm2 V represents the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the boom cylinder, respectively. sboom v sbucket v sarm These represent the target speeds of the boom cylinder, bucket cylinder, and stick cylinder, respectively. sboom,max v sbucket,max v sarm,max n represents the maximum target speed of the boom cylinder, bucket cylinder, and stick cylinder, respectively. m n represents the target rotational speed of the rotary motor. m,max V represents the maximum target speed of the rotary motor. m I represents the displacement of the rotary motor. j Indicates the handle signal, I j,max This indicates the maximum value of the handle signal.

[0046] Optionally, when the total demand flow rate Q1 of the first pump is less than or equal to the maximum outlet flow rate q of the first pump out1 Then, based on the total demand flow rate Q1 of the first pump and the theoretical leakage rate q of the first pump... x1 Given the engine speed n, calculate the required displacement V1 of the first pump. And calculate the variable control signal I of the first pump. p1 , b1 is the pump start signal, k1 is the pump proportional coefficient; and based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder and bucket cylinder, the valve core displacements of the proportional valves in the first and second flow distribution units are calculated:

[0047]

[0048]

[0049] Where, x boom and x bucket C represents the valve core displacement of the proportional valve in the first flow distribution unit and the second flow distribution unit, respectively. q The flow coefficient is related to temperature, W represents the circumference of the valve opening of the proportional valve, and p A,boom p B,boom p represents the rodless chamber pressure and the rod chamber pressure of the boom cylinder, respectively. A,bucket p B,bucket These represent the rodless chamber pressure and rod chamber pressure of the bucket cylinder, respectively, and p1 represents the outlet pressure of the first pump.

[0050] When the total demand flow rate Q1 of the first pump is greater than the maximum outlet flow rate q of the first pump out1 At that time, the first pump is at its maximum displacement, and the variable control signal for the first pump is I. p1 =I p,max The flow rate will then be allocated proportionally:

[0051]

[0052]

[0053] Where, q' boom and q' bucket The required flow rates of the boom cylinder and bucket cylinder are allocated proportionally.

[0054] The valve core displacement of the proportional valve in the first flow distribution unit and the second flow distribution unit is:

[0055]

[0056]

[0057] Optionally, when the total demand flow rate Q2 of the second pump is less than or equal to the maximum outlet flow rate q of the second pump... out2 Then, based on the total demand flow rate Q2 of the second pump and the theoretical leakage rate q of the second pump... x2 Given the engine speed n, calculate the required displacement V2 of the second pump. And calculate the variable control signal I of the second pump. p2 , b1 is the pump start signal, k1 is the pump proportional coefficient; and based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder and the rotary motor, the valve core displacements of the proportional valves in the third and fourth flow distribution units are calculated:

[0058]

[0059]

[0060] Where, x arm and x swing C represents the valve core displacement of the proportional valve in the third and fourth flow distribution units, respectively. q The flow coefficient is related to the real-time temperature value, W represents the valve opening perimeter of the proportional valve, and p A,arm p B,arm p represents the rodless chamber pressure and rod chamber pressure of the boom cylinder, respectively. A,swing p B,swing These represent the pressure at port A and port B of the rotary motor, respectively. When oil enters through port A, the rotation is clockwise, and when oil enters through port B, the rotation is counterclockwise. p2 represents the outlet pressure of the second pump.

[0061] When the total demand flow rate Q2 of the second pump is greater than the maximum outlet flow rate q of the second pump out2 The second pump is at maximum displacement, and the variable control signal for the second pump is I. p2 =I p,max Distribute the flow according to the proportion:

[0062]

[0063]

[0064] Where, q' arm and q' swing To proportionally allocate the required flow rates of the boom cylinder and the swing motor;

[0065] The valve core displacements of the proportional valves in the third and fourth flow distribution units are:

[0066]

[0067]

[0068] Optionally, the flow coefficient C related to the real-time temperature value... q The calculation formula is:

[0069] When Re ≤ 100000, C q =0.964×Re -0.05Where Re is the Reynolds number of the proportional valve, calculated using the following formula:

[0070]

[0071] v = q / (d × x)

[0072]

[0073] Where m is the average depth of the proportional valve, v is the average velocity of the oil flowing through the valve orifice of the proportional valve, d is the valve core diameter, W is the circumference of the proportional valve opening, x is the opening length of the proportional valve; ν represents the kinematic viscosity of the oil, which is related to the real-time temperature value.

[0074] When Re > 100000, C q It is a constant.

[0075] Optionally, the expressions for the control signals of the proportional valves in the first flow distribution unit, the second flow distribution unit, the third flow distribution unit, and the fourth flow distribution unit are as follows:

[0076]

[0077]

[0078]

[0079]

[0080] Among them, I v,boom I v,bucket I v,arm I v,swing These represent the control signals of the proportional valves in the first, second, third, and fourth flow distribution units, respectively. boom x bucket x represents the valve core displacement of the proportional valve in the first flow distribution unit and the second flow distribution unit, respectively. arm x swing I represents the valve core displacement of the proportional valve in the third and fourth flow distribution units, respectively. v,max is the maximum value of the proportional valve control signal, k2 is the proportional coefficient of the proportional valve, and b2 is the start signal of the proportional valve.

[0081] In a second aspect, the present invention provides an excavator including the flow distribution system suitable for multiple actuators as described in any one of the first aspects.

[0082] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0083] This invention not only fully decouples the control of the inlet and outlet ports of the actuator, reducing overflow losses caused by simultaneous throttling, but also takes into account temperature, a key factor affecting hydraulic oil viscosity, and accurately calculates the leakage of the pump and the flow rate of the valve port, realizing precise flow distribution and coordinated control of the pump and valve. This improves the efficiency of flow distribution, effectively reduces energy waste and overall machine performance instability caused by unreasonable flow distribution, and reduces the impact of extreme temperatures on the overall machine's operability. Attached Figure Description

[0084] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0085] Figure 1 This is a schematic diagram of the structure of a flow distribution system applicable to an excavator with multiple actuators according to an embodiment of the present invention;

[0086] Figure 2 This is a schematic diagram showing the relationship between the handle movement and the cylinder displacement direction in one embodiment of the present invention;

[0087] Figure 3 This is a schematic diagram illustrating the relationship between the handle's movement and the motor's rotation direction in one embodiment of the present invention;

[0088] in:

[0089] 1-Engine, 2-First pump, 3-Second pump, 4-First check valve, 5-First overflow valve, 6-Second overflow valve, 7-Third overflow valve, 8-Fourth overflow valve, 9-Second check valve, 10-First temperature and pressure sensor, 11-Second temperature and pressure sensor, 12-Third temperature and pressure sensor, 13-Fourth temperature and pressure sensor, 14-Fifth temperature and pressure sensor, 15-Sixth temperature and pressure sensor, 16-Seventh temperature and pressure sensor, 17-Eighth temperature and pressure sensor, 18-Ninth temperature and pressure sensor, 19-Tenth temperature and pressure sensor, 20-Boom cylinder, 21-Stick cylinder, 22-Bucket cylinder, 23-Slewing motor, 24-First flow distribution unit, 25-Third flow distribution unit, 26-Second flow distribution unit, 27-Fourth flow distribution unit. Detailed Implementation

[0090] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0091] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0092] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0093] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] The application principle of the present invention will be described in detail below with reference to the accompanying drawings.

[0095] Example 1

[0096] This invention provides a flow distribution system suitable for excavators with multiple actuators, comprising: a pump unit, several flow distribution units, and a controller;

[0097] A temperature and pressure sensor is installed at the outlet of the pump unit;

[0098] Each flow distribution unit includes an independently configured first proportional valve and second proportional valve. The oil inlets of the two valves are respectively connected to the pump unit. Port A of the first proportional valve and port B of the second proportional valve are respectively used to connect to the oil inlet and outlet of the corresponding actuator. Temperature and pressure sensors are respectively installed at port A of the first proportional valve and port B of the second proportional valve. In specific implementation, the first proportional valve and the second proportional valve can be selected as valves or valve groups, which can be selected according to the actual situation.

[0099] The controller's input terminals are connected to each temperature and pressure sensor, and its output terminals are connected to the pump unit and the first and second proportional valves in each flow distribution unit. Based on the acquired engine speed, oil parameters, relevant parameters of the pump unit, handle signal, and output signals of each temperature and pressure sensor, the controller calculates the control signals for the pump unit, the first proportional valve, and the second proportional valve, and controls the pump unit, the first proportional valve, and the second proportional valve according to the control signals to achieve flow distribution of multiple actuators.

[0100] In one specific embodiment of the present invention, the pump unit includes a first pump 2 and a second pump 3 arranged coaxially. Both the first pump 2 and the second pump 3 are provided with temperature and pressure sensors at their outlets. Specifically, the first pump 2 is provided with a first temperature and pressure sensor 10 at its outlet, and the second pump 3 is provided with a second temperature and pressure sensor 11 at its outlet.

[0101] In one specific embodiment of the present invention, the number of traffic allocation units is four, which are respectively referred to as the first traffic allocation unit 24, the second traffic allocation unit 26, the third traffic allocation unit 25 and the fourth traffic allocation unit 27.

[0102] The A port of the first proportional valve and the B port of the second proportional valve in the first flow distribution unit 24 are respectively used to connect to the rodless chamber and the rod chamber of the boom cylinder 20. The oil return ports of the first proportional valve and the second proportional valve are 24-1 and 24-2, which are the oil return positions. The oil inlet ports of the first proportional valve and the second proportional valve are 24-3 and 24-4.

[0103] The A port of the first proportional valve and the B port of the second proportional valve in the second flow distribution unit 26 are respectively used to connect to the rodless chamber and the rod chamber of the bucket cylinder 22. The return oil ports of the first proportional valve and the second proportional valve are 26-1 and 26-2, which are the return oil positions. The oil inlets of the first proportional valve and the second proportional valve are 26-3 and 26-4.

[0104] The A port of the first proportional valve and the B port of the second proportional valve in the third flow distribution unit 25 are respectively used to connect to the rodless chamber and the rod chamber of the boom cylinder 21. The oil return ports of the first proportional valve and the second proportional valve are 25-1 and 25-2, which are the oil return positions. The oil inlet ports of the first proportional valve and the second proportional valve are 25-3 and 25-4.

[0105] The A port of the first proportional valve and the B port of the second proportional valve in the fourth flow distribution unit 27 are respectively used to connect to the inlet and outlet ports of the rotary motor 23. The return ports of the first and second proportional valves are 27-1 and 27-2, which are the return positions. The inlet ports of the first and second proportional valves are 27-3 and 27-4.

[0106] The oil inlets of the first flow distribution unit 24 and the second flow distribution unit 26 are respectively connected to the oil outlet of the first pump 2.

[0107] The oil inlets of the third flow distribution unit 25 and the fourth flow distribution unit 27 are respectively connected to the oil outlet of the second pump 3.

[0108] In one specific embodiment of the present invention, the controller calculates the maximum theoretical flow rate and theoretical leakage of the first pump 2 and the second pump 3 based on the obtained engine speed, oil parameters, relevant parameters of the first pump 2 and the second pump 3, and the outlet pressure of the first pump 2 and the second pump 3, and then obtains the maximum outlet flow rate of the first pump 2 and the second pump 3.

[0109] The controller determines the target rotation speed of each actuator based on the handle signal and calculates the required flow rate of each actuator, thereby obtaining the total required flow rate of the first pump 2 and the second pump 3.

[0110] Based on the total demand flow of the first pump 2 and the second pump 3, and the maximum outlet flow of the first pump 2 and the second pump 3, the control signals of the first pump 2, the second pump 3, and the first proportional valve and the second proportional valve connected to each actuator are calculated.

[0111] In one specific embodiment of the present invention, the maximum outlet flow rate of the first pump 2 is calculated using the following formula:

[0112] q out1 =q l1 -q x1

[0113]

[0114] q l1 =nV max1

[0115] The maximum outlet flow rate of the second pump 3 is calculated using the following formula:

[0116] q out2 =q l2 -q x2

[0117]

[0118] q l2 =nV max2

[0119] Where, q out1 and q out2 q represents the maximum outlet flow rate of the first pump 2 and the maximum outlet flow rate of the second pump 3, respectively. l1 and q l2 q represents the maximum theoretical flow rate of the first pump 2 and the maximum theoretical flow rate of the second pump 3, respectively. x1 and q x2 P represents the theoretical leakage of the first pump 2 and the theoretical leakage of the second pump 3, respectively. d1 and P d2 K1 and K2 represent the outlet pressures of the first pump 2 and the second pump 3, respectively, and represent the structural parameters of the first pump 2 and the second pump 3, respectively. max1 and V max2 ν represents the maximum displacement of the first pump 2 and the maximum displacement of the second pump 3, respectively; n represents the engine speed; ν represents the kinematic viscosity of the oil; and ρ represents the oil density.

[0120] In one specific embodiment of the present invention, the total required flow rate of the first pump 2 is calculated using the following formula:

[0121] Q1 = q boom +q bucket

[0122] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q boom =0,q bucket =0;

[0123] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q boom =v sboom (A boom1 -A boom2 ), q bucket =v sbucket (A bucket1 -A bucket2 ),

[0124] When the load force of the hydraulic cylinder and the displacement of the hydraulic cylinder are not in the same direction, q boom=A boom ×v sboom q bucket =A bucket ×v sbucket ;

[0125] The total required flow rate of the second pump 3 is calculated using the following formula:

[0126] Q2 = q arm +q swing

[0127] q swing =n m ×V m

[0128]

[0129] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q arm =0;

[0130] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q arm =v sarm (A arm1 -A arm2 ),

[0131] When the load force of the hydraulic cylinder and the displacement of the hydraulic cylinder are not in the same direction, q arm =A arm ×v sarm ;

[0132] Where Q1 and Q2 represent the total demand flow rate of the first pump 2 and the total demand flow rate of the second pump 3, respectively. boom q bucket q arm q swing A represents the required flow rates of boom cylinder 20, bucket cylinder 22, stick cylinder 21, and swing motor 23, respectively. boom A bucket A arm A represents the working chamber area of ​​boom cylinder 20, bucket cylinder 22, and stick cylinder 21, respectively. boom1 A boom2 A represents the rodless chamber working area and the rod chamber working area of ​​the boom cylinder 20, respectively. bucket1 A bucket2 A represents the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the bucket cylinder 22, respectively. arm1 A arm2 V represents the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the boom cylinder 21, respectively. sboom vsbucket v sarm These represent the target speeds of boom cylinder 20, bucket cylinder 22, and stick cylinder 21, respectively. sboom,max v sbucket,max v sarm,max These represent the maximum target speeds of boom cylinder 20, bucket cylinder 22, and stick cylinder 21, respectively. m Indicates the target rotational speed of rotary motor 23, n m,max V represents the maximum target speed of the rotary motor 23. m Indicates the displacement of rotary motor 23, I j Indicates the handle signal, I j,max This indicates the maximum value of the handle signal.

[0133] In one specific embodiment of the present invention, when the total demand flow rate Q1 of the first pump 2 is less than or equal to the maximum outlet flow rate q of the first pump 2... out1 Based on the total demand flow rate Q1 of the first pump 2 and the theoretical leakage rate q of the first pump 2, x1 Given the engine speed n, calculate the required displacement V1 of the first pump 2. And calculate the variable control signal I of the first pump 2. p1 , b1 is the pump start signal, k1 is the pump proportional coefficient; and based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder 20 and bucket cylinder 22, the valve core displacements of the proportional valves in the first flow distribution unit 24 and the second flow distribution unit 26 are calculated:

[0134]

[0135]

[0136] Where, x boom and x bucket C represents the valve core displacement of the proportional valve in the first flow distribution unit 24 and the second flow distribution unit 26, respectively. q The flow coefficient is related to temperature, W represents the circumference of the valve opening of the proportional valve, and p A,boom p B,boom p represents the rodless chamber pressure and the rod chamber pressure of the boom cylinder 20, respectively. A,bucket p B,bucket These represent the rodless chamber pressure and rod chamber pressure of the bucket cylinder 22, respectively, and p1 represents the outlet pressure of the first pump 2;

[0137] When the total demand flow rate Q1 of the first pump 2 is greater than the maximum outlet flow rate q of the first pump 2 out1 At that time, the first pump 2 is at its maximum displacement, and the variable control signal for the first pump 2 is I. p1 =Ip,max The flow rate will then be allocated proportionally:

[0138]

[0139]

[0140] Where, q' boom and q' bucket The required flow rates of the boom cylinder 20 and bucket cylinder 22 are distributed proportionally.

[0141] The valve core displacement of the proportional valve in the first flow distribution unit 24 and the second flow distribution unit 26 is:

[0142]

[0143]

[0144] In one specific embodiment of the present invention, when the total demand flow rate Q2 of the second pump 3 is less than or equal to the maximum outlet flow rate q of the second pump 3... out2 Based on the total demand flow rate Q2 of the second pump 3 and the theoretical leakage rate q of the second pump 3, x2 Given the engine speed n, calculate the required displacement V2 of the second pump 3. And calculate the variable control signal I of the second pump 3. p2 , b1 is the pump start signal, k1 is the pump proportional coefficient; and based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder 21 and the rotary motor 23, the valve core displacements of the proportional valves in the third flow distribution unit 25 and the fourth flow distribution unit 27 are calculated:

[0145]

[0146]

[0147] Where, x arm and x swing C represents the valve core displacement of the proportional valve in the third flow distribution unit 25 and the fourth flow distribution unit 27, respectively. q The flow coefficient is related to the real-time temperature value, W represents the valve opening perimeter of the proportional valve, and p A,arm p B,arm p represents the rodless chamber pressure and rod chamber pressure of the boom cylinder 21, respectively. A,swing p B,swing These represent the pressure at port A and port B of the rotary motor 23, respectively. When oil enters through port A, the rotation is clockwise, and when oil enters through port B, the rotation is counterclockwise. p2 represents the outlet pressure of the second pump 3.

[0148] When the total demand flow rate Q2 of the second pump 3 is greater than the maximum outlet flow rate q of the second pump 3 out2 The second pump 3 is at maximum displacement, and the variable control signal for the second pump 3 is I. p2 =I p,max Distribute the flow according to the proportion:

[0149]

[0150]

[0151] Where, q' arm and q' swing To proportionally distribute the required flow rates of the boom cylinder 21 and the slewing motor 23;

[0152] The valve core displacements of the proportional valves in the third flow distribution unit 25 and the fourth flow distribution unit 27 are:

[0153]

[0154]

[0155] In one specific embodiment of the present invention, the flow coefficient C related to the real-time temperature value... q The calculation formula is:

[0156] When Re ≤ 100000, C q =0.964×Re -0.05 Where Re is the Reynolds number of the proportional valve, calculated using the following formula:

[0157]

[0158] v = q / (d × x)

[0159]

[0160] Where m is the average depth of the proportional valve, v is the average velocity of the oil flowing through the valve orifice of the proportional valve, d is the valve core diameter, W is the circumference of the proportional valve opening, x is the opening length of the proportional valve; ν represents the kinematic viscosity of the oil, which is related to the real-time temperature value.

[0161] When Re > 100000, C q It is a constant.

[0162] In one specific embodiment of the present invention, the expression for the control signal of the proportional valve in the first flow distribution unit 24, the second flow distribution unit 26, the third flow distribution unit 25, and the fourth flow distribution unit 27 is as follows:

[0163]

[0164]

[0165]

[0166]

[0167] Among them, I v,boom I v,bucket I v,arm I v,swing These represent the control signals of the proportional valves in the first flow distribution unit 24, the second flow distribution unit 26, the third flow distribution unit 25, and the fourth flow distribution unit 27, respectively. boom x bucket x represents the valve core displacement of the proportional valve in the first flow distribution unit 24 and the second flow distribution unit 26, respectively. arm x swing I represents the valve core displacement of the proportional valve in the third flow distribution unit 25 and the fourth flow distribution unit 27, respectively. v,max is the maximum value of the proportional valve control signal, k2 is the proportional coefficient of the proportional valve, and b2 is the start signal of the proportional valve.

[0168] The following is combined with Figure 1-3 The present invention provides a detailed description of a flow distribution system applicable to multiple actuators, and a specific embodiment thereof.

[0169] This invention employs an independent valve port control electro-hydraulic system. The oil inlet and outlet of each actuator's cylinder (or motor) are independently controlled by two independent proportional valves (groups). A first pump and a second pump are coaxially arranged. Temperature and pressure sensors are installed at the outlets of the first pump and the second pump, as well as in both chambers of each actuator's cylinder (or motor).

[0170] The specific connection method is as follows: Engine 1, first pump 2, and second pump 3 are coaxially connected. The outlet of first pump 2 is connected to second overflow valve 6 and first temperature and pressure sensor 10. The outlet of second pump 3 is connected to third overflow valve 7 and second temperature and pressure sensor 11. First pump 2 is connected to the P port of first proportional valve (i.e., valve (group) 1) and second proportional valve (i.e., valve (group) 2) in first flow distribution unit and second flow distribution unit, respectively. The A port of first proportional valve is connected to rodless chamber of boom cylinder 20 / bucket cylinder 22. The B port of second proportional valve is connected to rod chamber of boom cylinder 20 / bucket cylinder 22. The T ports of first proportional valve and second proportional valve are connected to oil tank through parallel assembly of first check valve 4 and first overflow valve 5. Second pump 3 is connected to the P port of first proportional valve (i.e., valve (group) 1) and second proportional valve (i.e., valve (group) 2) in third flow distribution unit and fourth flow distribution unit, respectively. The A port of first proportional valve in third flow distribution unit... The B port of the second proportional valve is connected to the rodless chamber (clockwise inlet) and rod chamber (counterclockwise inlet) of the boom cylinder, respectively. The A port of the first proportional valve and the B port of the second proportional valve in the fourth flow distribution unit are connected to the inlet and outlet ports of the swing motor, respectively. The T ports of the first and second proportional valves in the third and fourth flow distribution units are connected to the oil tank via a parallel assembly of the second check valve 9 and the fourth overflow valve 8. The third and fourth temperature and pressure sensors 12 and 13 are connected to the rodless and rod chambers of the boom cylinder, respectively. The fifth and sixth temperature and pressure sensors 14 and 15 are connected to the rodless and rod chambers of the boom cylinder, respectively. The seventh and eighth temperature and pressure sensors 16 and 17 are connected to the rodless and rod chambers of the bucket cylinder, respectively. The ninth and tenth temperature and pressure sensors 18 and 19 are connected to the rodless and rod chambers of the bucket cylinder, respectively. Each temperature and pressure sensor and the proportional valve are connected to the controller via a wiring harness. Specific connection methods are as follows: Figure 1 As shown.

[0171] The specific work process includes:

[0172] 1. Knowledge Acquisition

[0173] (1.1) The first pump 2 and the second pump 3 are the same pumps, and the pump variable control signal I p The correspondence between the pump displacement V and the pump displacement is as follows:

[0174] V = k1 × I p +b1 (1)

[0175] Where k1 is the pump's proportional coefficient and b1 is the pump's start signal, both k1 and b1 are determined experimentally. Specifically, at two different I... p The corresponding pump displacements are measured to calculate k1 and b1.

[0176] (1.2) The first and second proportional valves in each flow distribution unit are the same valves, and the control signal I of the proportional valve in the flow distribution unit corresponding to each actuator is the same. v The correspondence between the valve core displacement x and the valve core displacement x is as follows:

[0177] x=k2×I v +b2 (2)

[0178] Where k2 represents the proportional system of the proportional valve, and b2 is the start signal of the proportional valve. Both k2 and b2 are determined experimentally. Specifically, at two different I... v The valve core displacements of the corresponding control valves are measured respectively, and k2 and b2 are calculated accordingly.

[0179] (1.3) Determine the relationship between the kinematic viscosity ν of oil and temperature T: The empirical formula for the kinematic viscosity of oil and temperature is as follows:

[0180] lg(ν+0.65)=A-BlgT (3)

[0181] Where A and B are coefficients determined experimentally. The kinematic viscosity ν of the oil was measured at two different temperatures (T) to calculate A and B.

[0182] 2. Obtain engine speed n and handle signal I from the engine control unit. j The real-time temperature and pressure are fed back by temperature and pressure sensors at the pump outlet and the oil inlet and outlet of each actuator.

[0183] 3. Calculate the kinematic viscosity ν of the oil based on the real-time temperature and equation (3);

[0184] 4. Calculate the maximum theoretical flow rate and theoretical leakage of the first pump 2 and the second pump 3:

[0185] (4.1) Calculate the maximum theoretical flow rate q of the first pump 2 and the second pump 3 based on the engine speed. l1 and q l2 :

[0186] q l1 =nV max1

[0187] q l2 =nV max2

[0188] Where n represents engine speed, V max1 and V max2 These represent the maximum displacement of the first pump 2 and the maximum displacement of the second pump 3, respectively.

[0189] (4.2) Calculate the theoretical leakage q of the first pump 2 and the second pump 3 according to the formula for calculating the theoretical leakage of the pump.x1 and q x2 :

[0190]

[0191]

[0192] Among them, P d1 and P d2 K1 and K2 represent the outlet pressure of the first pump 2 and the outlet pressure of the second pump 3, respectively. K1 and K2 represent the structural parameters of the first pump 2 and the second pump 3, respectively (the values ​​of K1 and K2 are fixed after the pump model is determined). ν represents the kinematic viscosity of the oil and ρ represents the density of the oil.

[0193] 5. Calculate the maximum outlet flow rates of pump 2 and pump 3 respectively:

[0194] q out1 =q l1 -q x1

[0195] q out2 =q l2 -q x2

[0196] Where, q out1 and q out2 These represent the maximum outlet flow rate of the first pump 2 and the maximum outlet flow rate of the second pump 3, respectively.

[0197] 6. Calculate the total demand flow rate of the first pump 2 and the total demand flow rate of the second pump 3 respectively.

[0198] (6.1) The total required flow rate of the first pump 2 is calculated using the following formula:

[0199] Q1 = q boom +q bucket

[0200] Hydraulic cylinder flow regeneration condition judgment: Determine the displacement direction of the hydraulic cylinder based on the movement of the handle, such as... Figure 2 and 3 As shown. Then, based on the pressure P in the rodless chamber of the hydraulic cylinder... A Rod chamber pressure P B Calculate the load force F using the effective area A1 of the rodless cavity and the effective area A2 of the rod cavity:

[0201] F = P B ×A2-P A ×A1

[0202] When the cylinder load force and cylinder displacement direction are aligned, the cylinder load force acts as the driving force to move the cylinder. To prevent excessive speed from causing cavitation, a flow regeneration circuit is used to allow some of the returned oil flow to flow back into the inlet chamber for regeneration. Specifically, when the cylinder load force and cylinder displacement direction are aligned and both are positive, q boom =0,q bucket =0;

[0203] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q boom =v sboom (A boom1 -A boom2 ), q bucket =v sbucket (A bucket1 -A bucket2 ),

[0204] When the load force of the hydraulic cylinder and the displacement of the hydraulic cylinder are not in the same direction, q boom =A boom ×v sboom q bucket =A bucket ×v sbucket .

[0205] (6.2) The total required flow rate of the second pump 3 is calculated using the following formula:

[0206] Q2 = q arm +q swing

[0207] q swing =n m ×V m

[0208]

[0209] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q arm =0;

[0210] When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q arm =v sarm (A arm1 -A arm2 ),

[0211] When the load force of the hydraulic cylinder and the displacement of the hydraulic cylinder are not in the same direction, q arm =A arm ×v sarm ;

[0212] Where Q1 and Q2 represent the total demand flow rates of the first pump and the second pump, respectively, q boom q bucket q arm q swing A represents the required flow rates of the boom cylinder, bucket cylinder, stick cylinder, and swing motor, respectively. boom A bucket A arm A represents the working chamber area of ​​the boom cylinder, bucket cylinder, and stick cylinder, respectively. boom1 A boom2 A represents the rodless chamber working area and the rod chamber working area of ​​the boom cylinder, respectively. bucket1 A bucket2 Let A represent the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the bucket cylinder, respectively. arm1 A arm2 V represents the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the boom cylinder, respectively. sboom v sbucket v sarm These represent the target speeds of the boom cylinder, bucket cylinder, and stick cylinder, respectively. sboom,max v sbucket,max v sarm,max n represents the maximum target speed of the boom cylinder, bucket cylinder, and stick cylinder, respectively. m n represents the target rotational speed of the rotary motor. m,max V represents the maximum target speed of the rotary motor. m I represents the displacement of the rotary motor. j Indicates the handle signal, I j,max This indicates the maximum value of the handle signal.

[0213] 7. Calculate the Reynolds number for each control valve, and then determine the relationship between the Reynolds number and the flow coefficient C. q The flow coefficient is calculated based on the corresponding relationship:

[0214] The average depth m of the control valve is calculated using the following formula:

[0215]

[0216] Where W is the perimeter of the control valve opening and x is the length of the control valve opening.

[0217] The Reynolds number Re of the control valve is calculated using the following formula:

[0218]

[0219] v = q / (d × x)

[0220] Where v is the average velocity of the oil flowing through the valve port, and d is the valve core diameter.

[0221] Reynolds number Re and flow coefficient C q The relationship is: when Re ≤ 100000, C q =0.964×Re -0.05 When Re > 100000, C q It is a constant, ranging from 0.6 to 0.62.

[0222] When Q1≤q out1 The first pump 2 can meet the working requirements of the boom and bucket. At this time, it is necessary to control the first pump 2 by variables. Based on the total required flow rate of the first pump 2 and the theoretical leakage q of the first pump 2, x1 Based on the engine speed, the required displacement V1 of the first pump 2 is calculated. And calculate the variable control signal I of the first pump 2. p1 , b1 is the pump start signal, and k1 is the pump proportional coefficient;

[0223] To reduce some of the throttling losses, flow control is achieved by throttling at the cylinder outlet. Based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder 20 and bucket cylinder 22, the valve core displacements of the proportional valves in the first flow distribution unit 24 and the second flow distribution unit 26 are calculated.

[0224]

[0225]

[0226] Where, x boom and x bucket C represents the valve core displacement of the proportional valve in the first flow distribution unit 24 and the second flow distribution unit 26, respectively. q The flow coefficient is related to the real-time temperature value, W represents the valve opening perimeter of the proportional valve, and p A,boom p B,boom p represents the rodless chamber pressure and the rod chamber pressure of the boom cylinder 20, respectively. A,bucket p B,bucket These represent the rodless chamber pressure and rod chamber pressure of the bucket cylinder 22, respectively, and p1 represents the outlet pressure of the first pump 2;

[0227] When Q1 > q out1 At this time, the first pump 2 cannot meet the working requirements of the boom and bucket, the first pump 2 is at maximum displacement, and the variable control signal of the first pump 2 is I. p1 =I p,max The flow rate will then be allocated proportionally:

[0228]

[0229]

[0230] Where, q' boom and q' bucket The required flow rates of the boom cylinder 20 and stick cylinder 21 are distributed proportionally.

[0231] The valve core displacement of the proportional valve in the first flow distribution unit 24 and the second flow distribution unit 26 is:

[0232]

[0233]

[0234] Among them, C q This is the flow coefficient.

[0235] When Q2≤q out2 If the second pump 3 can meet the working requirements of the boom and slewing, then based on the total required flow rate of the second pump 3 and the theoretical leakage q of the second pump 3... x2 Based on the engine speed, the required displacement V2 of the second pump 3 is calculated. And calculate the variable control signal I of the second pump 3. p2 ,

[0236] To reduce some of the throttling losses, flow control is achieved by throttling at the cylinder outlet. Based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder 21 (cylinder extension is port B, retraction is port A) and the rotary motor 23 (rotation clockwise is port B, counterclockwise is port A), the valve core displacements of the proportional valves in the third flow distribution unit 25 and the fourth flow distribution unit 27 are calculated.

[0237]

[0238]

[0239] Where, x arm and x swing C represents the valve core displacement of the proportional valve in the first flow distribution unit 24 and the second flow distribution unit 26, respectively. q The flow coefficient is represented by W, the valve opening circumference of the proportional valve is represented by p. A,arm p B,arm p represents the rodless chamber pressure and rod chamber pressure of the boom cylinder 21, respectively. A,swing p B,swing p1 and p2 represent the pressure at port A and port B of the rotary motor 23, respectively, and p2 represents the outlet pressure of the second pump 3.

[0240] When Q2>qout2 The second pump 3 is at maximum displacement, and the variable control signal for the first pump 2 is I. p1 =I p,max Distribute the flow according to the proportion:

[0241]

[0242]

[0243] Where, q' arm and q' swing To proportionally distribute the required flow rates of the boom cylinder 21 and the slewing motor 23;

[0244] The valve core displacements of the proportional valves in the third flow distribution unit 25 and the fourth flow distribution unit 27 are:

[0245]

[0246]

[0247] Calculate the control signals for the boom, stick, bucket, and swing control valves [I] v,boom ,I v,arm ,I v,bucket ,I v,swing ]:

[0248]

[0249]

[0250]

[0251]

[0252] Among them, I v,boom I v,arm I v,bucket I v,swing These represent the control signals of the proportional valves in the first flow distribution unit 24, the second flow distribution unit 26, the third flow distribution unit 25, and the fourth flow distribution unit 27, respectively. v,max This represents the maximum value of the proportional valve control signal.

[0253] Example 2

[0254] This invention provides an excavator, including the flow distribution system suitable for multiple actuators as described in any one of embodiments 1.

[0255] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0256] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A flow distribution system suitable for excavators with multiple actuators, characterized in that, include: The pump unit is equipped with a temperature and pressure sensor at its outlet. Several flow distribution units, each flow distribution unit includes an independently set first proportional valve and second proportional valve, the oil inlet of the two valves are respectively connected to the pump unit, the A port of the first proportional valve and the B port of the second proportional valve are respectively used to connect to the oil inlet and outlet ports of the corresponding actuators, and temperature and pressure sensors are respectively provided at the A port of the first proportional valve and the B port of the second proportional valve. The controller has its input terminals connected to each temperature and pressure sensor, and its output terminals connected to the pump unit and the first and second proportional valves in each flow distribution unit. Based on the obtained engine speed, oil parameters, relevant parameters of the pump unit, handle signal, and output signals of each temperature and pressure sensor, the controller calculates the control signals of the pump unit, the first proportional valve, and the second proportional valve, and controls the pump unit, the first proportional valve, and the second proportional valve according to the control signals to realize the flow distribution of multiple actuators. The pump unit includes a first pump and a second pump arranged coaxially, and both the first pump and the second pump are equipped with temperature and pressure sensors at their outlets. The number of the flow distribution units is four, which are respectively referred to as the first flow distribution unit, the second flow distribution unit, the third flow distribution unit and the fourth flow distribution unit; The A port of the first proportional valve and the B port of the second proportional valve in the first flow distribution unit are respectively used to connect to the rodless chamber and the rod chamber of the boom cylinder. The A port of the first proportional valve and the B port of the second proportional valve in the second flow distribution unit are respectively used to connect to the rodless chamber and the rod chamber of the bucket cylinder. The A port of the first proportional valve and the B port of the second proportional valve in the third flow distribution unit are respectively used to connect to the rodless chamber and the rod chamber of the boom cylinder. The A port of the first proportional valve and the B port of the second proportional valve in the fourth flow distribution unit are respectively used to connect to the inlet and outlet oil ports of the rotary motor. The oil inlets of the first flow distribution unit and the second flow distribution unit are respectively connected to the oil outlet of the first pump; The oil inlets of the third flow distribution unit and the fourth flow distribution unit are respectively connected to the oil outlet of the second pump. Based on the obtained engine speed, oil parameters, relevant parameters of the first and second pumps, and outlet pressure of the first and second pumps, the controller calculates the maximum theoretical flow rate and theoretical leakage of the first and second pumps, and then obtains the maximum outlet flow rate of the first and second pumps. The controller determines the target rotational speed of each actuator based on the handle signal and calculates the required flow rate of each actuator, thereby obtaining the total required flow rate of the first pump and the second pump. Based on the total required flow rate of the first and second pumps, and the maximum outlet flow rate of the first and second pumps, the control signals for the first pump, the second pump, and the first and second proportional valves connected to each actuator are calculated.

2. The flow distribution system for excavators with multiple actuators according to claim 1, characterized in that: The maximum outlet flow rate of the first pump is calculated using the following formula: q out1 =q l1 -q x1 q l1 =nV max1 The maximum outlet flow rate of the second pump is calculated using the following formula: q out2 =q l2 -q x2 q l2 =nV max2 Where, q out1 and q out2 q represents the maximum outlet flow rate of the first pump and the maximum outlet flow rate of the second pump, respectively. l1 and q l2 q represents the maximum theoretical flow rate of the first pump and the maximum theoretical flow rate of the second pump, respectively. x1 and q x2 P represents the theoretical leakage of the first pump and the theoretical leakage of the second pump, respectively. d1 and P d2 K1 and K2 represent the outlet pressures of the first and second pumps, respectively, and the structural parameters of the first and second pumps, respectively. max1 and V max2 These represent the maximum displacement of the first pump and the maximum displacement of the second pump, respectively. n represents the engine speed, ν represents the kinematic viscosity of the oil, and ρ represents the oil density.

3. A flow distribution system suitable for excavators with multiple actuators according to claim 1, characterized in that: The total required flow rate of the first pump is calculated using the following formula: Q1=q boom +q bucket When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q boom =0,q bucket =0; When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q boom =v sboom (A boom1 -A boom2 ), q bucket =v sbucket (A bucket1 -A bucket2 ), When the load force of the hydraulic cylinder is not in the same direction as the displacement of the hydraulic cylinder, q boom =A boom ×v sboom q bucket =A bucket ×v sbucket ; The total required flow rate of the second pump is calculated using the following formula: Q2=q arm +q swing q swing =n m ×V m When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are positive, q arm =0; When the load force of the hydraulic cylinder is in the same direction as the displacement of the hydraulic cylinder, and both are negative, q arm =v sarm (A arm1 -A arm2 ), When the load force of the hydraulic cylinder is not in the same direction as the displacement of the hydraulic cylinder, q arm =A arm ×v sarm ; Where Q1 and Q2 represent the total demand flow rates of the first pump and the second pump, respectively, q boom q bucket q arm q swing A represents the required flow rates of the boom cylinder, bucket cylinder, stick cylinder, and swing motor, respectively. boom A bucket A arm A represents the working chamber area of ​​the boom cylinder, bucket cylinder, and stick cylinder, respectively. boom1 A boom2 A represents the rodless chamber working area and the rod chamber working area of ​​the boom cylinder, respectively. bucket1 A bucket2 Let A represent the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the bucket cylinder, respectively. arm1 A arm2 V represents the working area of ​​the rodless chamber and the working area of ​​the rod chamber of the boom cylinder, respectively. sboom v sbucket v sarm These represent the target speeds of the boom cylinder, bucket cylinder, and stick cylinder, respectively. sboom,max v sbucket,max v sarm,max n represents the maximum target speed of the boom cylinder, bucket cylinder, and stick cylinder, respectively. m n represents the target rotational speed of the rotary motor. m,max V represents the maximum target speed of the rotary motor. m Indicates the displacement of the rotary motor, I j Indicates the handle signal, I j,max This indicates the maximum value of the handle signal.

4. A flow distribution system suitable for excavators with multiple actuators according to claim 1, characterized in that: When the total demand flow rate Q1 of the first pump is less than or equal to the maximum outlet flow rate q of the first pump out1 Then, based on the total demand flow rate Q1 of the first pump and the theoretical leakage rate q of the first pump... x1 Given the engine speed n, calculate the required displacement V1 of the first pump. And calculate the variable control signal I of the first pump. p1 , b1 is the pump start signal, k1 is the pump proportional coefficient; and based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder and bucket cylinder, the valve core displacements of the proportional valves in the first and second flow distribution units are calculated: Where, x boom and x bucket C represents the valve core displacement of the proportional valve in the first flow distribution unit and the second flow distribution unit, respectively. q The flow coefficient is related to temperature, W represents the circumference of the valve opening of the proportional valve, and p A,boom p B,boom p represents the rodless chamber pressure and the rod chamber pressure of the boom cylinder, respectively. A,bucket p B,bucket These represent the rodless chamber pressure and rod chamber pressure of the bucket cylinder, respectively, and p1 represents the outlet pressure of the first pump. When the total demand flow rate Q1 of the first pump is greater than the maximum outlet flow rate q of the first pump out1 At that time, the first pump is at its maximum displacement, and the variable control signal for the first pump is I. p1 =I p,max The flow rate will then be allocated proportionally: Where, q' boom and q' bucket The required flow rates of the boom cylinder and bucket cylinder are allocated proportionally. The valve core displacement of the proportional valve in the first flow distribution unit and the second flow distribution unit is:

5. A flow distribution system suitable for excavators with multiple actuators according to claim 1, characterized in that: When the total demand flow rate Q2 of the second pump is less than or equal to the maximum outlet flow rate q of the second pump out2 Then, based on the total demand flow rate Q2 of the second pump and the theoretical leakage rate q of the second pump... x2 Given the engine speed n, calculate the required displacement V2 of the second pump. And calculate the variable control signal I of the second pump. p2 , b1 is the pump start signal, k1 is the pump proportional coefficient; and based on the real-time temperature and pressure values ​​fed back by the temperature and pressure sensors at the outlets of the boom cylinder and the rotary motor, the valve core displacements of the proportional valves in the third and fourth flow distribution units are calculated: Where, x arm and x swing C represents the valve core displacement of the proportional valve in the third and fourth flow distribution units, respectively. q The flow coefficient is related to the real-time temperature value, W represents the valve opening perimeter of the proportional valve, and p A,arm p B,arm p represents the rodless chamber pressure and rod chamber pressure of the boom cylinder, respectively. A,swing p B,swing These represent the pressure at port A and port B of the rotary motor, respectively. When oil enters through port A, the rotation is clockwise, and when oil enters through port B, the rotation is counterclockwise. p2 represents the outlet pressure of the second pump. When the total demand flow rate Q2 of the second pump is greater than the maximum outlet flow rate q of the second pump out2 The second pump is at maximum displacement, and the variable control signal for the second pump is I. p2 =I p,max Distribute the flow according to the proportion: Where, q' arm and q' swing To proportionally allocate the required flow rates of the boom cylinder and the swing motor; The valve core displacements of the proportional valves in the third and fourth flow distribution units are:

6. A flow distribution system suitable for excavators with multiple actuators according to claim 4 or 5, characterized in that: The flow coefficient C related to the real-time temperature value q The calculation formula is: When Re ≤ 100000, C q =0.964×Re -0.05 Where Re is the Reynolds number of the proportional valve, calculated using the following formula: v = q / (d × x) Where m is the average depth of the proportional valve, v is the average velocity of the oil flowing through the valve orifice of the proportional valve, d is the valve core diameter, W is the circumference of the proportional valve opening, x is the opening length of the proportional valve; ν represents the kinematic viscosity of the oil, which is related to the real-time temperature value. When Re > 100000, C q It is a constant.

7. A flow distribution system suitable for excavators with multiple actuators according to claim 1, characterized in that: The expressions for the control signals of the proportional valves in the first, second, third, and fourth flow distribution units are as follows: Among them, I v,boom I v,bucket I v,arm I v,swing These represent the control signals of the proportional valves in the first, second, third, and fourth flow distribution units, respectively. boom x bucket x represents the valve core displacement of the proportional valve in the first flow distribution unit and the second flow distribution unit, respectively. arm x swing I represents the valve core displacement of the proportional valve in the third and fourth flow distribution units, respectively. v,max is the maximum value of the proportional valve control signal, k2 is the proportional coefficient of the proportional valve, and b2 is the start signal of the proportional valve.

8. An excavator, characterized in that, The system includes the flow distribution system applicable to multiple actuators as described in any one of claims 1-7.

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