Parallel hydraulic system, method, device for excavator and excavator

Abstract

The application provides a parallel hydraulic system, method, device and excavator for the excavator, which comprises a temperature sensor, a pressure sensor, a controller, an oil tank, a first motor, a second motor and a variable pump which are connected to form an oil circuit, the first motor is connected with a compressor of an air conditioner, the second motor is connected with a fan of a radiator, the first motor and the second motor are connected in parallel and are connected in series with the variable pump, and are connected to the oil tank respectively, the temperature sensor is connected with the oil tank, the pressure sensor is connected to the oil circuit, and the controller is electrically connected with the variable pump, the temperature sensor and the pressure sensor respectively, the first motor connected with the compressor of the air conditioner and the second motor connected with the fan of the radiator are connected in parallel and share one variable pump, the driving of the fan and the compressor of the radiator is realized, linkage control of the two motors under different loads is ensured, and cost is reduced.

Description

Parallel hydraulic systems, methods, devices, and excavators for excavators Technical Field

[0001] This invention relates to the field of hydraulic technology, and more particularly to a parallel hydraulic system, method, apparatus, and excavator for use in excavators. Background Technology

[0002] The existing structure of a traditional hydraulic excavator is shown in Figure 1. The excavator mainly consists of a superstructure 1, a traveling device 2, and a working device 3. Based on this, and with the increasing demand for new energy technologies, electric excavators have emerged. Especially for trolley-mounted excavators, which require connection to the external power grid via a transformer and then supply power to the superstructure 1, the high power consumption of these excavators necessitates higher voltage transmission. This results in higher costs when the motor drives the radiator fan and air conditioning compressor. Summary of the Invention

[0003] This invention provides a parallel hydraulic system, method, device, and excavator for excavators, which solves the problems of existing excavators needing to connect to the upper device from the external power grid through a transformer, large excavators having large power and requiring high voltage power transmission, and the hydraulic system for driving the radiator fan and air conditioning compressor by the motor having a complex layout and high cost.

[0004] According to a first aspect of the present invention, a parallel hydraulic system for an excavator includes: a temperature sensor, a pressure sensor, a controller, and an oil tank, a first motor, a second motor, and a variable displacement pump connected to each other to form an oil circuit; the first motor is connected to the compressor of an air conditioner; the second motor is connected to the fan of a radiator; the first motor and the second motor are connected in parallel and then connected in series with the variable displacement pump, and are respectively connected to the oil tank; the temperature sensor is connected to the oil tank; the pressure sensor is connected to the oil circuit; and the controller is electrically connected to the variable displacement pump, the temperature sensor, and the pressure sensor respectively.

[0005] According to one embodiment of the present invention, the system further includes: a flow valve, and a first reversing valve, a second reversing valve, and a third reversing valve arranged in parallel with each other; wherein the flow valve is connected in series with the first motor; the first reversing valve is connected in series with the first motor; the second reversing valve is connected in series with the second motor; one end of the third reversing valve is connected to the variable pump, and the other end of the third reversing valve is connected to the oil tank.

[0006] Specifically, this embodiment provides an implementation of a flow valve, a first reversing valve, a second reversing valve, and a third reversing valve.

[0007] According to a second aspect of the present invention, a control method for the above-described parallel hydraulic system for an excavator is provided, applied to a controller, the method comprising:

[0008] Obtain the compressor's status parameters and the oil tank's temperature parameters;

[0009] Based on the state parameters and the temperature parameters, a regulation strategy for regulating the hydraulic circuit and a preset system pressure are determined. The regulation strategy includes at least regulating the flow direction of the hydraulic oil in the hydraulic circuit and the displacement of the variable pump. The preset system pressure is the pressure in the hydraulic circuit.

[0010] Based on the aforementioned adjustment strategy, the instantaneous system pressure within the oil circuit is adjusted until the preset system pressure is met.

[0011] According to one embodiment of the present invention, the step of determining the adjustment strategy for the oil circuit and the preset system pressure based on the state parameters and the temperature parameters specifically includes:

[0012] When the status parameter indicates that the compressor is in a working state, the first reversing valve and the third reversing valve are energized, wherein the first reversing valve is connected in series with the first motor, and the third reversing valve is connected in parallel with the first reversing valve;

[0013] Based on the temperature parameter, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a first preset pressure and a second preset pressure. The first preset pressure is the pressure difference between the two ends when the second motor requires the minimum flow rate, and the second preset pressure is the pressure difference between the two ends when the second motor requires the maximum flow rate.

[0014] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

[0015] According to one embodiment of the present invention, the step of determining the adjustment strategy and the preset system pressure based on the temperature parameter specifically includes:

[0016] When the instantaneous temperature indicated by the temperature parameter is equal to the first temperature value, the second reversing valve is energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure.

[0017] When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to the second temperature value, the second reversing valve is energized, and the adjustment strategy is determined based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure.

[0018] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve is de-energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure.

[0019] The second reversing valve is connected in series with the second motor.

[0020] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and the preset system pressure.

[0021] According to one embodiment of the present invention, the step of adjusting the instantaneous system pressure in the oil circuit based on the adjustment strategy until the preset system pressure is met further includes:

[0022] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, and the instantaneous system pressure is determined to be less than the first preset pressure, the displacement of the variable pump is increased until the instantaneous system pressure is equal to the first preset pressure.

[0023] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, and the instantaneous system pressure is determined to be greater than the first preset pressure, the displacement of the variable pump is reduced until the instantaneous system pressure is equal to the first preset pressure.

[0024] Specifically, this embodiment provides an implementation method for adjusting the instantaneous system pressure in the oil circuit until the preset system pressure is met.

[0025] According to one embodiment of the present invention, the step of determining the adjustment strategy for the oil circuit and the preset system pressure based on the state parameters and the temperature parameters specifically includes:

[0026] When the status parameter indicates that the compressor is in a non-working state, the first reversing valve is de-energized and the third reversing valve is energized, wherein the first reversing valve is connected in series with the first motor and the third reversing valve is connected in parallel with the first reversing valve;

[0027] Based on the temperature parameter, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a first preset pressure and a second preset pressure. The first preset pressure is the pressure difference between the two ends when the second motor requires the minimum flow rate, and the second preset pressure is the pressure difference between the two ends when the second motor requires the maximum flow rate.

[0028] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

[0029] According to one embodiment of the present invention, the step of determining the adjustment strategy and the preset system pressure based on the temperature parameter specifically includes:

[0030] Based on the energization of the second reversing valve, when the instantaneous temperature indicated by the temperature parameter is greater than or equal to the first temperature value, the adjustment strategy is determined according to the instantaneous system pressure being equal to the first preset pressure.

[0031] Based on the energization of the second reversing valve, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to the second temperature value, the adjustment strategy is determined according to the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure.

[0032] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second and third directional valves are de-energized, and the adjustment strategy is determined according to the minimum displacement of the variable pump.

[0033] The second reversing valve is connected in series with the second motor.

[0034] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and the preset system pressure.

[0035] According to a third aspect of the present invention, a control device for a parallel hydraulic system of an excavator includes:

[0036] The parameter acquisition module is used to acquire the compressor's status parameters and the oil tank's temperature parameters.

[0037] The strategy determination module is used to determine the adjustment strategy and preset system pressure of the hydraulic circuit based on the state parameters and the temperature parameters. The adjustment strategy includes at least adjusting the flow direction of the hydraulic oil in the hydraulic circuit and the displacement of the variable pump. The preset system pressure is the pressure in the hydraulic circuit.

[0038] The strategy execution module is used to adjust the instantaneous system pressure in the oil circuit according to the adjustment strategy until the preset system pressure is met.

[0039] An excavator according to a fourth aspect of the present invention includes the above-described parallel hydraulic system for an excavator;

[0040] Alternatively, when controlling the hydraulic system of an excavator, the control method described above for the parallel hydraulic system of an excavator may be used.

[0041] Alternatively, it may include the aforementioned control device for a parallel hydraulic system used in excavators.

[0042] The above-mentioned one or more technical solutions of the present invention have at least one of the following technical effects: The parallel hydraulic system, method, device and excavator provided by the present invention, by setting the first motor connected to the air conditioner compressor and the second motor connected to the radiator fan in parallel and sharing a variable pump, realizes the drive of the radiator fan and the compressor, ensuring the linkage control of the two motors under different loads, and also reducing costs. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 is a schematic diagram of the assembly relationship of an existing excavator;

[0045] Figure 2 is one of the schematic diagrams showing the arrangement of the parallel hydraulic system for an excavator provided by the present invention;

[0046] Figure 3 is a second schematic diagram of the arrangement of the parallel hydraulic system for excavators provided by the present invention;

[0047] Figure 4 is a flowchart illustrating the control method for a parallel hydraulic system for an excavator provided by the present invention.

[0048] Figure 5 is one of the schematic diagrams showing the change of system power in the control method of the parallel hydraulic system for excavators provided by the present invention;

[0049] Figure 6 is a second schematic diagram of the change in system power in the control method of the parallel hydraulic system for excavators provided by the present invention;

[0050] Figure 7 is a schematic diagram of the structure of the control device for the parallel hydraulic system of an excavator provided by the present invention.

[0051] Figure label:

[0052] 1. Loading device; 2. Traveling device; 3. Working device;

[0053] 10. Air conditioner; 11. Compressor; 20. Radiator; 21. Fan; 30. Temperature sensor; 40. Pressure sensor; 50. Controller; 60. Oil tank; 70. First motor; 80. Second motor; 90. Variable pump; 100. Flow valve; 110. First directional valve; 120. Second directional valve; 130. Third directional valve;

[0054] 200. Parameter Acquisition Module; 300. Strategy Determination Module; 400. Strategy Execution Module. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all embodiments. 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.

[0056] The present invention will now be described in detail with reference to the accompanying drawings. The specific operation methods in the method embodiments can also be applied to the device embodiments or system embodiments. In the description of the present invention, unless otherwise stated, "at least one" includes one or more. "Multiple" refers to two or more. For example, at least one of A, B, and C includes: A existing alone, B existing alone, A and B existing simultaneously, A and C existing simultaneously, B and C existing simultaneously, and A, B, and C existing simultaneously. In the present invention, " / " means "or". For example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0057] The following is a detailed description with reference to Figures 2 to 7 of this invention.

[0058] In some specific embodiments of the present invention, as shown in Figures 2 and 3, this solution provides a parallel hydraulic system for an excavator, including: a temperature sensor 30, a pressure sensor 40, a controller 50, and an oil tank 60, a first motor 70, a second motor 80, and a variable pump 90 connected to each other to form an oil circuit; the first motor 70 is connected to the compressor 11 of the air conditioner 10; the second motor 80 is connected to the fan 21 of the radiator 20; the first motor 70 and the second motor 80 are connected in parallel and then connected in series with the variable pump 90, and are respectively connected to the oil tank 60; the temperature sensor 30 is connected to the oil tank 60; the pressure sensor 40 is connected to the oil circuit; and the controller 50 is electrically connected to the variable pump 90, the temperature sensor 30, and the pressure sensor 40 respectively.

[0059] It should be noted that by setting the first motor 70 and the second motor 80 in parallel and by setting a variable pump 90, the present invention achieves the linkage control of the air conditioner 10, compressor 11, radiator 20 and fan 21 by a variable pump 90, which reduces the complexity of the hydraulic system layout of the radiator 20 and air conditioner 10 on the excavator and the equipment cost. At the same time, the hydraulic system controls the two motors more simply and conveniently, reduces the failure rate, and improves the reliability of the system.

[0060] In some possible embodiments of the present invention, it further includes: a flow valve 100, and a first reversing valve 110, a second reversing valve 120 and a third reversing valve 130 arranged in parallel with each other; wherein, the flow valve 100 is arranged in series with the first motor 70; the first reversing valve 110 is arranged in series with the first motor 70; the second reversing valve 120 is arranged in series with the second motor 80; one end of the third reversing valve 130 is connected to the variable pump 90, and the other end of the third reversing valve 130 is connected to the oil tank 60.

[0061] Specifically, this embodiment provides an implementation of a flow valve 100, a first reversing valve 110, a second reversing valve 120, and a third reversing valve 130. The arrangement of the flow valve 100, the first reversing valve 110, the second reversing valve 120, and the third reversing valve 130 enables the driving of the fan 21 and the compressor 11 of the radiator 20, while ensuring the linkage control of the two motors under different loads.

[0062] In some specific embodiments of the present invention, as shown in Figures 2 to 6, the present invention provides a control method for a parallel hydraulic system of an excavator, applied to a controller 50, the method comprising:

[0063] Obtain the status parameters of compressor 11 and the temperature parameters of oil tank 60;

[0064] Based on state parameters and temperature parameters, determine the adjustment strategy and preset system pressure for the hydraulic circuit. The adjustment strategy includes at least adjusting the flow direction of hydraulic oil in the hydraulic circuit and the displacement of variable pump 90. The preset system pressure is the pressure in the hydraulic circuit.

[0065] Based on the adjustment strategy, the instantaneous system pressure in the oil circuit is adjusted until the preset system pressure is met.

[0066] In some possible embodiments of the present invention, as shown in FIG6, the steps of determining the adjustment strategy for regulating the oil circuit and the preset system pressure based on state parameters and temperature parameters specifically include:

[0067] When the status parameter indicates that the compressor 11 is in the working state, the first reversing valve 110 and the third reversing valve 130 are energized. The first reversing valve 110 is connected in series with the first motor 70, and the third reversing valve 130 is connected in parallel with the first reversing valve 110.

[0068] Based on temperature parameters, an adjustment strategy and a preset system pressure are determined. The preset system pressure includes at least a first preset pressure and a second preset pressure. The first preset pressure is the pressure difference between the two ends of the second motor 80 at the minimum required flow rate, and the second preset pressure is the pressure difference between the two ends of the second motor 80 at the maximum required flow rate.

[0069] Specifically, this embodiment provides an implementation method for determining the adjustment strategy of the oil circuit and the preset system pressure. When the compressor 11 is in operation, the first reversing valve 110 and the third reversing valve 130 are energized. At the same time, the system pressure is adjusted in real time according to the temperature feedback of the oil tank 60, so as to realize the control of the operating status of the parallel air conditioner 10 and radiator 20.

[0070] In some possible embodiments of the present invention, the steps of determining the adjustment strategy and preset system pressure based on temperature parameters specifically include:

[0071] When the instantaneous temperature indicated by the temperature parameter is equal to the first temperature value, the second reversing valve 120 is energized and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure.

[0072] When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to the second temperature value, the second reversing valve 120 is energized and a regulation strategy is determined based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure.

[0073] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 120 is de-energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure.

[0074] The second reversing valve 120 is connected in series with the second motor 80.

[0075] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and preset system pressure. By classifying the three cases of instantaneous temperature indicated by the temperature parameter when the compressor 11 is in working state, the instantaneous system pressure is adjusted according to the different instantaneous temperatures of the oil tank 60 to meet the control of the hydraulic parallel system under different conditions.

[0076] It should be noted that the second directional valve 120 is connected in series with the second motor 80, which enables the regulation of the working state of the second motor 80 through the second directional valve 120.

[0077] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than or equal to the first temperature value, the hydraulic oil is delivered from the variable pump 90, passes through the second directional valve 120 and the second motor 80 in sequence, and then flows back to the oil tank 60; at the same time, the hydraulic oil is delivered from the variable pump 90 and enters another parallel path, passes through the first directional valve 110, the flow valve 100 and the first motor 70 in sequence, and then flows back to the oil tank 60.

[0078] In a possible embodiment, the displacement of the variable pump 90 is increased until the instantaneous system pressure fed back by the pressure sensor 40 meets the preset system pressure, wherein the instantaneous system pressure can reach the first preset pressure when the instantaneous temperature indicated by the temperature parameter is equal to the first temperature value.

[0079] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than a first temperature value and less than or equal to a second temperature value, the regulating flow rate of the variable pump 90 is between the sum of the minimum required flow rate of the second motor 80 and the loop required flow rate of the first motor 70, and the sum of the maximum required flow rate of the second motor 80 and the loop required flow rate of the first motor 70.

[0080] In some possible embodiments of the present invention, the step of adjusting the instantaneous system pressure in the oil circuit until a preset system pressure is met, based on an adjustment strategy, further includes:

[0081] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, and the instantaneous system pressure is determined to be less than the first preset pressure, the displacement of the variable pump 90 increases until the instantaneous system pressure equals the first preset pressure.

[0082] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, and the instantaneous system pressure is determined to be greater than the first preset pressure, the displacement of the variable pump 90 is reduced until the instantaneous system pressure equals the first preset pressure.

[0083] Specifically, this embodiment provides an implementation method for adjusting the instantaneous system pressure in the oil circuit until the preset system pressure is met. When the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the displacement of the variable pump 90 is adjusted accordingly based on the different instantaneous system pressures, so that the instantaneous system pressure can quickly meet the preset system pressure.

[0084] In a possible embodiment, if the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the hydraulic oil is delivered from the variable pump 90 and then flows back to the oil tank 60 through the first directional valve 110, the flow valve 100 and the first motor 70 in sequence.

[0085] In some possible embodiments of the present invention, as shown in FIG6, the steps of determining the adjustment strategy for regulating the oil circuit and the preset system pressure based on state parameters and temperature parameters specifically include:

[0086] When the status parameter indicates that the compressor 11 is in a non-working state, the first reversing valve 110 is de-energized and the third reversing valve 130 is energized. The first reversing valve 110 is connected in series with the first motor 70, and the third reversing valve 130 is connected in parallel with the first reversing valve 110.

[0087] Based on temperature parameters, an adjustment strategy and a preset system pressure are determined. The preset system pressure includes at least a first preset pressure and a second preset pressure. The first preset pressure is the pressure difference between the two ends of the second motor 80 at the minimum required flow rate, and the second preset pressure is the pressure difference between the two ends of the second motor 80 at the maximum required flow rate.

[0088] Specifically, this embodiment provides an implementation method for determining the adjustment strategy of the oil circuit and the preset system pressure. When the compressor 11 is in a non-working state, the first reversing valve 110 is de-energized and the third reversing valve 130 is energized. At the same time, based on the temperature feedback of the oil tank 60, the system pressure is adjusted in real time to achieve the control of the operating status of the parallel air conditioner 10 and radiator 20.

[0089] In some possible embodiments of the present invention, the steps of determining the adjustment strategy and preset system pressure based on temperature parameters specifically include:

[0090] Based on the energization of the second reversing valve 120, when the instantaneous temperature indicated by the temperature parameter is greater than or equal to the first temperature value, the adjustment strategy is determined according to the instantaneous system pressure being equal to the first preset pressure.

[0091] Based on the energization of the second reversing valve 120, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to the second temperature value, the adjustment strategy is determined based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure.

[0092] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 120 and the third reversing valve 130 are de-energized, and the adjustment strategy is determined according to the minimum displacement of the variable pump 90.

[0093] The second reversing valve 120 is connected in series with the second motor 80.

[0094] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and preset system pressure. By classifying the two cases of instantaneous temperature marked by the temperature parameter when the compressor 11 is in a non-working state, it realizes the adjustment of the instantaneous system pressure according to the different instantaneous temperatures of the oil tank 60, so as to meet the control of the hydraulic parallel system under different conditions.

[0095] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than or equal to the first temperature value, the hydraulic oil is delivered from the variable pump 90 and then flows back to the oil tank 60 through the second directional valve 120 and the second motor 80 in sequence.

[0096] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than or equal to a first temperature value, the displacement of the variable pump 90 increases until the instantaneous system pressure fed back by the pressure sensor 40 meets the preset system pressure, wherein when the instantaneous temperature is equal to the first temperature value, the instantaneous system pressure is equal to the first preset pressure.

[0097] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than a first temperature value and less than or equal to a second temperature value, the regulating flow rate of the variable pump 90 is between the sum of the minimum required flow rate of the second motor 80 and the loop required flow rate of the first motor 70, and the sum of the maximum required flow rate of the second motor 80 and the loop required flow rate of the first motor 70.

[0098] The present invention will now be described in detail with reference to specific embodiments.

[0099] In one application scenario, as shown in Figure 5, the hydraulic circuit calculation of the present invention is as follows:

[0100] 1. Set two values ​​T1 and T2 for the temperature sensor 30 to measure the temperature range. When the measured value T is in the range of T1≤T≤T2, the power requirement of the fan 21 of the heat sink 20 should vary within the range of P2≤P. 风 ≤P3.

[0101] Furthermore, when the hydraulic oil temperature in the oil tank 60 is T1, the minimum power requirement of the fan 21 in the radiator 20 is P2 (kW).

[0102] Furthermore, when the hydraulic oil temperature in the oil tank 60 is T2, the maximum power required by the fan 21 of the radiator 20 is P3 (kW).

[0103] Furthermore, the compressor 11 of the air conditioner 10 requires a constant power P4 (kW), and under normal excavator operating conditions, P3 > P2 > P4.

[0104] 2. The second motor 80 that drives the fan 21 has a rated pressure p2 (MPa), a rated displacement v2 (ml / r), a volumetric efficiency y2, and a coupling mechanical efficiency x2.

[0105] Furthermore, according to the power-speed curve of fan 21, when fan 21 reaches its minimum power P2 at speed n2 (r / min), the actual minimum power of the second motor 80 is: P 21 =P2*x2(kw).

[0106] Furthermore, when fan 21 reaches its maximum power P3 at a speed n3 (r / min), the actual maximum power of the second motor 80 is: P 31 =P3*x2(kw).

[0107] 3. Since the second motor 80 driving the fan 21 of the radiator 20 has a large power, the hydraulic circuit flow rate should be prioritized to meet the minimum power P of the second motor 80. 21 and maximum power P 31 .

[0108] Furthermore, since the loop flow rate of the second motor 80 is a variable value, the minimum required flow rate is Q2 = v2*n2 / (y2*1000) (L / min); in addition, the pressure difference p across the second motor 80 is... 21 =P 21 *60000 / (v2*n2)(Mpa).

[0109] Furthermore, since the loop flow rate of the second motor 80 is a variable value, the maximum loop flow rate required by the second motor 80 is Q3 = v2*n3 / (y2*1000) (L / min). The pressure difference p across the second motor 80 is... 31 =P 31 *60000 / (v2*n2)(Mpa).

[0110] 4. The first motor 70 that drives the compressor 11 has a rated pressure p4 (MPa), a rated displacement v4 (ml / r), a volumetric efficiency y4, a pulley mechanical efficiency x4, and a pulley transmission ratio i.

[0111] Furthermore, according to the compressor power-speed curve, the power P4 is achieved at a speed n4 (r / min). The actual speed n of the first motor 70 is... 41 =n4*i, the actual power of the first motor 70 is: P 41 =P4*x4(kw).

[0112] Furthermore, the circuit flow requirement of the first motor 70 is a fixed value, Q4 = n 41 *i*v4 / 1000(L / min).

[0113] Furthermore, the actual pressure p at both ends of the first motor 70 41 =P 41 *60000 / (n 41 *i*v4)(Mpa).

[0114] It should be noted that a pulley and a drive belt are required during the transmission connection between the first motor 70 and the compressor 11.

[0115] 5. The rated pressure p1 (MPa), rated displacement v1 (ml / r), rated speed n1 (r / min), and volumetric efficiency y1 of the variable displacement pump 90 are given. The rated pressure satisfies p1 > p 31 Rated flow rate Q1 = v1 * n1, actual flow rate Q 11 Condition Q must be met 11 =y1*Q1≥Q3+Q4.

[0116] Furthermore, the rated power: P1 = p1*v1*n1 / (1000*60) = p1*v1*n1 / 60000 (kW), must satisfy the condition y1*P1 > P 31 +P 41 .

[0117] 6. The pressure compensation for the flow valve 100 is selected as p5. p5 and p 21 p 41 The relationship is p5 = 0.8 (p 21 -p 41 ).

[0118] Therefore, the pressure setting of flow valve 100 is p5 = p 21 =0.8*(P 21 *60000 / (v2*n2)-P 41 *60000 / (n 41 *v4))(Mpa).

[0119] 7. Calculation of the orifice area A0 of flow valve 100, pipe diameter D (mm), hydraulic oil density ρ, and selection of flow coefficient C when the orifice diameter ratio A0 / D < 1 / 7 and incomplete contraction. d =0.2~0.7, according to the thin-walled small hole equation

[0120] In some specific embodiments of the present invention, as shown in FIG7, the present invention provides a control device for a parallel hydraulic system of an excavator, comprising:

[0121] The parameter acquisition module 200 is used to acquire the status parameters of the compressor 11 and the temperature parameters of the oil tank 60;

[0122] The strategy determination module 300 is used to determine the adjustment strategy and preset system pressure of the hydraulic circuit based on the state parameters and temperature parameters. The adjustment strategy includes at least adjusting the flow direction of the hydraulic oil in the hydraulic circuit and the displacement of the variable pump 90. The preset system pressure is the pressure in the hydraulic circuit.

[0123] The strategy execution module 400 is used to adjust the instantaneous system pressure in the oil circuit according to the adjustment strategy until the preset system pressure is met.

[0124] Optionally, the steps for determining the regulation strategy of the regulating oil circuit and the preset system pressure based on state parameters and temperature parameters specifically include:

[0125] When the status parameter indicates that the compressor 11 is in the working state, the first reversing valve 110 and the third reversing valve 130 are energized. The first reversing valve 110 is connected in series with the first motor 70, and the third reversing valve 130 is connected in parallel with the first reversing valve 110.

[0126] Based on temperature parameters, an adjustment strategy and a preset system pressure are determined. The preset system pressure includes at least a first preset pressure and a second preset pressure. The first preset pressure is the pressure difference between the two ends of the second motor 80 at the minimum required flow rate, and the second preset pressure is the pressure difference between the two ends of the second motor 80 at the maximum required flow rate.

[0127] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

[0128] Optionally, the steps of determining the regulation strategy and preset system pressure based on temperature parameters specifically include:

[0129] When the instantaneous temperature indicated by the temperature parameter is equal to the first temperature value, the second reversing valve 120 is energized and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure.

[0130] When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to the second temperature value, the second reversing valve 120 is energized and a regulation strategy is determined based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure.

[0131] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 120 is de-energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure.

[0132] The second reversing valve 120 is connected in series with the second motor 80.

[0133] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and preset system pressure.

[0134] Optionally, the step of adjusting the instantaneous system pressure in the oil circuit until the preset system pressure is met, based on the adjustment strategy, further includes:

[0135] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, and the instantaneous system pressure is determined to be less than the first preset pressure, the displacement of the variable pump 90 increases until the instantaneous system pressure equals the first preset pressure.

[0136] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, and the instantaneous system pressure is determined to be greater than the first preset pressure, the displacement of the variable pump 90 is reduced until the instantaneous system pressure equals the first preset pressure.

[0137] Specifically, this embodiment provides an implementation method for adjusting the instantaneous system pressure in the oil circuit until a preset system pressure is met.

[0138] Optionally, the steps for determining the regulation strategy of the regulating oil circuit and the preset system pressure based on state parameters and temperature parameters specifically include:

[0139] When the status parameter indicates that the compressor 11 is in a non-working state, the first reversing valve 110 is de-energized and the third reversing valve 130 is energized. The first reversing valve 110 is connected in series with the first motor 70, and the third reversing valve 130 is connected in parallel with the first reversing valve 110.

[0140] Based on temperature parameters, an adjustment strategy and a preset system pressure are determined. The preset system pressure includes at least a first preset pressure and a second preset pressure. The first preset pressure is the pressure difference between the two ends of the second motor 80 at the minimum required flow rate, and the second preset pressure is the pressure difference between the two ends of the second motor 80 at the maximum required flow rate.

[0141] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

[0142] Optionally, the steps of determining the regulation strategy and preset system pressure based on temperature parameters specifically include:

[0143] Based on the energization of the second reversing valve 120, when the instantaneous temperature indicated by the temperature parameter is greater than or equal to the first temperature value, the adjustment strategy is determined according to the instantaneous system pressure being equal to the first preset pressure.

[0144] Based on the energization of the second reversing valve 120, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to the second temperature value, the adjustment strategy is determined based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure.

[0145] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 120 and the third reversing valve 130 are de-energized, and the adjustment strategy is determined according to the minimum displacement of the variable pump 90.

[0146] The second reversing valve 120 is connected in series with the second motor 80.

[0147] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and preset system pressure.

[0148] In some specific embodiments of the present invention, as shown in Figures 2 to 7, the present invention provides an excavator including the above-described parallel hydraulic system for an excavator;

[0149] Alternatively, when controlling the hydraulic system of an excavator, the control method described above for the parallel hydraulic system of an excavator may be used.

[0150] Alternatively, it may include the aforementioned control device for a parallel hydraulic system used in excavators.

[0151] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0152] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a parallel hydraulic system of an excavator, characterized in that, The system is applied to a controller and includes: a temperature sensor, a pressure sensor, a controller, and an oil tank, a first motor, a second motor, and a variable pump connected to each other to form an oil circuit; the first motor is connected to the compressor of an air conditioner; the second motor is connected to the fan of a radiator; the first motor and the second motor are connected in parallel and then connected in series with the variable pump, and are respectively connected to the oil tank; the temperature sensor is connected to the oil tank; the pressure sensor is connected to the oil circuit; the controller is electrically connected to the variable pump, the temperature sensor, and the pressure sensor respectively; it also includes: a flow valve, and a first reversing valve, a second reversing valve, and a third reversing valve connected in parallel, for driving the fan and compressor of the radiator, and for linkage control of the first motor and the second motor under different loads; wherein, the flow valve is connected in series with the first motor; the first reversing valve is connected in series with the first motor; the second reversing valve is connected in series with the second motor; one end of the third reversing valve is connected to the variable pump, and the other end of the third reversing valve is connected to the oil tank; the method includes: obtaining The compressor's status parameters and the oil tank's temperature parameters are used as the basis for determining a regulation strategy and a preset system pressure for the hydraulic circuit. The regulation strategy includes at least adjusting the flow direction of the hydraulic oil in the hydraulic circuit and the displacement of the variable pump. The preset system pressure is the pressure within the hydraulic circuit. Based on the regulation strategy, the instantaneous system pressure within the hydraulic circuit is adjusted until the preset system pressure is met. Specifically, determining the regulation strategy and preset system pressure based on the status parameters and the temperature parameters includes: when the status parameters indicate that the compressor is in a working state, energizing a first reversing valve and a third reversing valve, wherein the first reversing valve is connected in series with the first motor, and the third reversing valve is connected in parallel with the first reversing valve; determining the regulation strategy and the preset system pressure based on the temperature parameters, wherein the preset system pressure includes at least a first preset pressure and a second preset pressure, where the first preset pressure is the pressure difference between the two ends under the minimum flow requirement of the second motor, and the second preset pressure is the pressure difference between the two ends under the maximum flow requirement of the second motor.

2. The control method for a parallel hydraulic system of an excavator according to claim 1, characterized in that, The step of determining the adjustment strategy and the preset system pressure based on the temperature parameter specifically includes: when the instantaneous temperature indicated by the temperature parameter is equal to a first temperature value, the second directional valve is energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure; when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to a second temperature value, the second directional valve is energized, and the adjustment strategy is determined based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure; when the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second directional valve is de-energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the first preset pressure; wherein, the second directional valve is connected in series with the second motor.

3. The control method for a parallel hydraulic system of an excavator according to claim 2, characterized in that, The step of adjusting the instantaneous system pressure in the oil circuit based on the adjustment strategy until the preset system pressure is met further includes: when the instantaneous temperature indicated by the temperature parameter is less than a first temperature value, determining that the instantaneous system pressure is less than the first preset pressure, increasing the displacement of the variable pump until the instantaneous system pressure equals the first preset pressure; when the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, determining that the instantaneous system pressure is greater than the first preset pressure, decreasing the displacement of the variable pump until the instantaneous system pressure equals the first preset pressure.

4. The control method for a parallel hydraulic system of an excavator according to claim 1, characterized in that, The step of determining the adjustment strategy and preset system pressure of the oil circuit based on the state parameters and the temperature parameters specifically includes: when the state parameters indicate that the compressor is in a non-working state, the first reversing valve is de-energized and the third reversing valve is energized, wherein the first reversing valve is connected in series with the first motor, and the third reversing valve is connected in parallel with the first reversing valve; and determining the adjustment strategy and the preset system pressure based on the temperature parameters, wherein the preset system pressure includes at least a first preset pressure and a second preset pressure, the first preset pressure being the pressure difference between the two ends under the minimum flow requirement of the second motor, and the second preset pressure being the pressure difference between the two ends under the maximum flow requirement of the second motor.

5. The control method for a parallel hydraulic system of an excavator according to claim 4, characterized in that, The step of determining the adjustment strategy and the preset system pressure based on the temperature parameter specifically includes: when the second directional valve is energized, and the instantaneous temperature indicated by the temperature parameter is greater than or equal to a first temperature value, determining the adjustment strategy based on the instantaneous system pressure being equal to the first preset pressure; when the second directional valve is energized, and the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and less than or equal to a second temperature value, determining the adjustment strategy based on the instantaneous system pressure being greater than the first preset pressure and less than or equal to the second preset pressure; when the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, de-energizing the second and third directional valves, and determining the adjustment strategy based on the minimum displacement of the variable pump; wherein the second directional valve is connected in series with the second motor.

6. A control device for a parallel hydraulic system of an excavator, characterized in that, The system includes: a temperature sensor, a pressure sensor, a controller, and an oil tank, a first motor, a second motor, and a variable pump connected to each other to form an oil circuit; the first motor is connected to the compressor of an air conditioner; the second motor is connected to the fan of a radiator; the first motor and the second motor are connected in parallel and then connected in series with the variable pump, and are respectively connected to the oil tank; the temperature sensor is connected to the oil tank; the pressure sensor is connected to the oil circuit; the controller is electrically connected to the variable pump, the temperature sensor, and the pressure sensor respectively; it also includes: a flow valve, and a first reversing valve, a second reversing valve, and a third reversing valve connected in parallel, for driving the fan and compressor of the radiator, and for the linkage control of the first motor and the second motor under different loads; wherein, the flow valve is connected in series with the first motor; the first reversing valve is connected in series with the first motor; the second reversing valve is connected in series with the second motor; one end of the third reversing valve is connected to the variable pump, and the other end of the third reversing valve is connected to the oil tank; the device includes: a parameter acquisition module for acquiring the state parameters of the compressor. The system includes a state parameter and a temperature parameter of the oil tank; a strategy determination module, used to determine a regulation strategy and a preset system pressure for regulating the hydraulic circuit based on the state parameter and the temperature parameter, wherein the regulation strategy includes at least adjusting the flow direction of the hydraulic oil in the hydraulic circuit and the displacement of the variable pump, and the preset system pressure is the pressure in the hydraulic circuit; a strategy execution module, used to adjust the instantaneous system pressure in the hydraulic circuit according to the regulation strategy until the preset system pressure is met; the step of determining the regulation strategy and the preset system pressure for regulating the hydraulic circuit based on the state parameter and the temperature parameter specifically includes: when the state parameter indicates that the compressor is in a working state, the first reversing valve and the third reversing valve are energized, wherein the first reversing valve is connected in series with the first motor, and the third reversing valve is connected in parallel with the first reversing valve; the regulation strategy and the preset system pressure are determined based on the temperature parameter, wherein the preset system pressure includes at least a first preset pressure and a second preset pressure, wherein the first preset pressure is the pressure difference between the two ends under the minimum flow requirement of the second motor, and the second preset pressure is the pressure difference between the two ends under the maximum flow requirement of the second motor.

7. An excavator, characterized in that, The method includes, when performing excavator hydraulic system control, the control method for a parallel hydraulic system of an excavator as described in any one of claims 1 to 5; or, the control device for a parallel hydraulic system of an excavator as described in claim 6.

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