Series hydraulic system, method, device and excavator for an excavator

Abstract

The application provides a series 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, the second motor and the variable pump are arranged in series and are connected to the oil tank respectively, the temperature sensor is connected with the oil tank, 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 arranged in series, and a variable pump is shared, so that the fan of the radiator and the compressor are driven, linkage control of the two motors under different loads is ensured, and cost is reduced.

Description

Technical Field

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

[0002] Existing traditional hydraulic excavator structures, such as Figure 1 As shown, an excavator mainly consists of a chassis 1, a traveling mechanism 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 power from an external power grid via a transformer to the chassis 1, the high power consumption 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 series 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 series 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 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, the second motor, and the variable pump are arranged in series and respectively connected to the oil tank; the temperature sensor is connected to the oil tank; and the controller is electrically connected to the variable pump, the temperature sensor, and the pressure sensor respectively.

[0005] According to one embodiment of the present invention, the device further includes: a first relief valve, which is connected in parallel with the first motor and in series with the second motor; a first directional valve, which is connected in parallel with the first motor and the first relief valve and in series with the second motor; a second relief valve, which is connected in parallel with the second motor and in series with the first motor; a second directional valve, which is connected in parallel with the second motor and the second relief valve and in series with the first motor; and a flow valve, which is connected in series with the first motor.

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

[0007] According to a second aspect of the present invention, a control method for the above-described series hydraulic system for an excavator, 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 is energized, wherein the first reversing valve is connected in parallel with the first motor;

[0013] Based on the temperature parameters, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a first preset pressure, a second preset pressure, and a third preset pressure. The first preset pressure is the sum of the first overflow pressure of the first relief valve and the pressure difference between the two ends of the second motor at the minimum required flow rate. The second preset pressure is the sum of the first overflow pressure of the first relief valve and the pressure difference between the two ends of the second motor at the maximum required flow rate. The third preset pressure is the first overflow pressure of the first relief valve.

[0014] The first overflow valve is connected in parallel with the first motor and in series with the second motor.

[0015] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

[0016] 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:

[0017] 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 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.

[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 third preset pressure.

[0019] The second reversing valve is connected in parallel 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] When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value, the displacement of the variable pump increases until the instantaneous system pressure meets the preset system pressure, wherein the displacement of the variable pump is greater than the minimum flow rate required by the second motor and less than or equal to the maximum flow rate required by the second motor.

[0023] When the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the hydraulic oil delivered by the variable pump flows sequentially through the second directional valve, the flow valve, and the first motor before returning to the oil tank. The flow valve is connected in series with the first motor, and the second motor is in a non-operating state.

[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, wherein the first reversing valve is connected in parallel with the first motor;

[0027] Based on the temperature parameter, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a fourth preset pressure and a fifth preset pressure. The fourth preset pressure is the pressure difference between the two ends when the second motor requires the minimum flow rate, and the fifth 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 the first temperature value and equal to the second temperature value, the adjustment strategy is determined according to the instantaneous system pressure being greater than the fourth preset pressure and less than or equal to the fifth preset pressure.

[0031] 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 according to the minimum displacement of the variable pump.

[0032] The second reversing valve is connected in parallel with the second motor.

[0033] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and the preset system pressure.

[0034] According to one embodiment of the present invention, the step of determining the adjustment strategy based on the minimum displacement of the variable pump specifically includes:

[0035] Based on the minimum displacement of the variable pump, the hydraulic oil flows through the second directional valve and the first directional valve, and then flows back to the oil tank.

[0036] The radiator fan is in a non-working state, and the fan is connected in parallel with the second reversing valve.

[0037] Specifically, this embodiment provides an implementation method for determining the adjustment strategy based on the minimum displacement of the variable pump.

[0038] According to a third aspect of the present invention, a control device for a series hydraulic system of an excavator includes:

[0039] The parameter acquisition module is used to acquire the compressor's status parameters and the oil tank's temperature parameters.

[0040] 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.

[0041] 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.

[0042] An excavator according to a fourth aspect of the present invention includes the above-described series hydraulic system for an excavator;

[0043] Alternatively, when controlling the hydraulic system of an excavator, the control method described above for a series hydraulic system of an excavator may be used.

[0044] Alternatively, it may include the control device for the series hydraulic system of an excavator as described above.

[0045] The above-mentioned one or more technical solutions of the present invention have at least one of the following technical effects: The present invention provides a series hydraulic system, method, device and excavator for excavators, which realizes the driving of the radiator fan and compressor by setting the first motor connected to the air conditioner compressor and the second motor connected to the radiator fan in series and sharing a variable pump. This ensures the linkage control of the two motors under different loads and also reduces costs. Attached Figure Description

[0046] 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.

[0047] Figure 1 This is a schematic diagram of the assembly relationship of an existing excavator;

[0048] Figure 2 This is one of the schematic diagrams showing the arrangement of a series hydraulic system for an excavator provided by the present invention;

[0049] Figure 3 This is the second schematic diagram of the arrangement of a series hydraulic system for an excavator provided by the present invention;

[0050] Figure 4 This is a flowchart illustrating the control method for a series hydraulic system for an excavator provided by the present invention.

[0051] Figure 5 This is one of the schematic diagrams showing the change in system power in the control method for a series hydraulic system for an excavator provided by the present invention;

[0052] Figure 6 This is the second schematic diagram of the system power variation in the control method for a series hydraulic system of an excavator provided by the present invention;

[0053] Figure 7 This is the third schematic diagram of the system power variation in the control method for a series hydraulic system of an excavator provided by the present invention;

[0054] Figure 8This is a schematic diagram of the structure of the control device for the series hydraulic system of an excavator provided by the present invention.

[0055] Figure label:

[0056] 1. Loading device; 2. Traveling device; 3. Working device;

[0057] 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 relief valve; 120. First directional valve; 130. Second relief valve; 140. Second directional valve;

[0058] 200. Parameter Acquisition Module; 300. Strategy Determination Module; 400. Strategy Execution Module. Detailed Implementation

[0059] 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.

[0060] 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.

[0061] The following is an in conjunction with the present invention. Figures 2 to 8 Please provide a detailed explanation.

[0062] In some specific embodiments of the present invention, such as Figure 2 and Figure 3As shown, this solution provides a series 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, the second motor 80, and the variable pump 90 are connected in series and respectively connected to the oil tank 60; the temperature sensor 30 is connected to the oil tank 60; and the controller 50 is electrically connected to the variable pump 90, the temperature sensor 30, and the pressure sensor 40 respectively.

[0063] It should be noted that by connecting the first motor 70 and the second motor 80 in series and using 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. This reduces the complexity and cost of the hydraulic system layout of the radiator 20 and air conditioner 10 on the excavator. At the same time, the hydraulic system controls the two motors more simply and conveniently, reducing the failure rate and improving the reliability of the system.

[0064] In some possible embodiments of the present invention, the invention further includes: a first relief valve 110, which is connected in parallel with the first motor 70 and connected in series with the second motor 80; a first directional valve 120, which is connected in parallel with the first motor 70 and the first relief valve 110, and connected in series with the second motor 80; a second relief valve 130, which is connected in parallel with the second motor 80 and connected in series with the first motor 70; a second directional valve 140, which is connected in parallel with the second motor 80 and the second relief valve 130, and connected in series with the first motor 70; and a flow valve 100, which is connected in series with the first motor 70.

[0065] Specifically, this embodiment provides a valve group implementation method. By connecting a first overflow valve 110, a second overflow valve 130, a flow valve 100, a first reversing valve 120, and a second reversing valve 140 in parallel within the oil circuit of the first motor 70 and the second motor 80 connected in series, it is possible to independently control the air conditioner 10 and the radiator 20 according to their different operating states and the different loads of the first motor 70 and the second motor 80.

[0066] In some specific embodiments of the present invention, such as Figures 2 to 7 As shown, this solution provides a control method for a series hydraulic system of an excavator, applied to a controller 50, the method including:

[0067] Obtain the status parameters of compressor 11 and the temperature parameters of oil tank 60;

[0068] 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.

[0069] Based on the adjustment strategy, the instantaneous system pressure in the oil circuit is adjusted until the preset system pressure is met.

[0070] In some possible embodiments of the present invention, such as Figure 6 As shown, the steps for determining the regulation strategy and preset system pressure of the regulating oil circuit based on state parameters and temperature parameters specifically include:

[0071] When the status parameter indicates that the compressor 11 is in the working state, the first reversing valve 120 is energized, wherein the first reversing valve 120 is connected in parallel with the first motor 70;

[0072] 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, a second preset pressure, and a third preset pressure. The first preset pressure is the sum of the first overflow pressure of the first relief valve 110 and the pressure difference between the two ends of the second motor 80 at the minimum required flow rate. The second preset pressure is the sum of the first overflow pressure of the first relief valve 110 and the pressure difference between the two ends of the second motor 80 at the maximum required flow rate. The third preset pressure is the first overflow pressure of the first relief valve 110.

[0073] The first overflow valve 110 is connected in parallel with the first motor 70 and in series with the second motor 80.

[0074] 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 120 is energized, and 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 air conditioner 10 and radiator 20 connected in series.

[0075] 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:

[0076] Based on the energization of the second reversing valve 140, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and 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.

[0077] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 140 is de-energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the third preset pressure.

[0078] The second reversing valve 140 and the second motor 80 are connected in parallel.

[0079] 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 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 series system under different conditions.

[0080] In a possible embodiment, after the temperature sensor 30 detects that the oil temperature in the oil tank 60 has reached the first temperature value, the second reversing valve 140 is energized, the variable pump 90 starts to work, the hydraulic oil passes through the second motor 80, the second motor 80 drives the fan 21 of the radiator 20 to work, and the hydraulic oil then passes through the flow valve 100 and the first motor 70 to drive the compressor 11 of the air conditioner 10 to work.

[0081] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value, the displacement of the variable pump 90 increases, the outlet pressure of the variable pump 90 increases, and the pressure sensor 40 feeds back the instantaneous system pressure in the oil circuit to the controller 50.

[0082] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is equal to the first temperature value, the displacement of the variable pump 90 increases, and the outlet pressure of the variable pump 90 increases until the pressure sensor 40 detects that the instantaneous system pressure is equal to the second preset pressure.

[0083] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the temperature sensor 30 detects that the instantaneous temperature in the oil tank 60 is less than the first temperature value, the second directional valve 140 is de-energized, and the hydraulic oil output by the variable pump 90 flows back to the oil tank 60 after passing through the second directional valve 140, the flow valve 100 and the first motor 70 in sequence. At this time, the second motor 80 does not work, and the displacement of the variable pump 90 decreases until the pressure sensor 40 detects that the instantaneous system pressure is equal to the third preset pressure.

[0084] 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:

[0085] When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value, the displacement of the variable pump 90 increases until the instantaneous system pressure meets the preset system pressure. The displacement of the variable pump 90 is greater than the minimum required flow rate of the second motor 80 and less than or equal to the maximum required flow rate of the second motor 80.

[0086] When the instantaneous temperature indicated by the temperature parameter is lower than the first temperature value, the hydraulic oil delivered by the variable pump 90 flows sequentially through the second directional valve 140, the flow valve 100 and the first motor 70, and then flows back to the oil tank 60. The flow valve 100 is connected in series with the first motor 70, and the second motor 80 is in a non-working state.

[0087] Specifically, this embodiment provides an implementation method for adjusting the instantaneous system pressure in the oil circuit until a preset system pressure is met.

[0088] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than a first temperature value and equal to a second temperature value, the hydraulic oil displacement output by the variable pump 90 is greater than the minimum required flow rate of the second motor 80 and less than or equal to the maximum required flow rate of the second motor 80.

[0089] In a possible embodiment, when the hydraulic oil flow rate provided by the variable pump 90 is greater than the set value of the flow valve 100, the excess hydraulic oil is unloaded from the first relief valve 110 and flows back to the oil tank 60.

[0090] In some possible embodiments of the present invention, such as Figure 7 As shown, the steps for determining the regulation strategy and preset system pressure of the regulating oil circuit based on state parameters and temperature parameters specifically include:

[0091] When the status parameter indicates that the compressor 11 is in a non-working state, the first reversing valve 120 is de-energized, wherein the first reversing valve 120 is connected in parallel with the first motor 70;

[0092] Based on temperature parameters, an adjustment strategy and preset system pressure are determined. The preset system pressure includes at least a fourth preset pressure and a fifth preset pressure. The fourth preset pressure is the pressure difference between the two ends of the second motor 80 at the minimum required flow rate, and the fifth preset pressure is the pressure difference between the two ends of the second motor 80 at the maximum required flow rate.

[0093] 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 120 is de-energized and the second reversing valve 140 is 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 air conditioner 10 and radiator 20 connected in series.

[0094] 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:

[0095] Based on the energization of the second reversing valve 140, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and equal to the second temperature value, the adjustment strategy is determined based on the instantaneous system pressure being greater than the fourth preset pressure and less than or equal to the fifth preset pressure.

[0096] If the instantaneous temperature indicated by the temperature parameter is lower than the first temperature value, the second reversing valve 140 is de-energized, and the adjustment strategy is determined based on the minimum displacement of the variable pump 90.

[0097] The second reversing valve 140 and the second motor 80 are connected in parallel.

[0098] 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 series system under different conditions.

[0099] In a possible embodiment, when the compressor 11 is not in operation, the first reversing valve 120 is de-energized. When the temperature sensor 30 detects that the instantaneous temperature of the oil tank 60 reaches the first temperature value, the second reversing valve 140 is energized, the variable pump 90 is activated, the hydraulic oil flows through the second motor 80, drives the fan 21 of the radiator 20 to work, and then the hydraulic oil flows back to the oil tank 60 through the first reversing valve 120.

[0100] In a possible embodiment, when the temperature sensor 30 detects that the instantaneous temperature is greater than the first temperature value, the displacement of the variable pump 90 increases, the outlet pressure of the variable pump 90 increases, and the pressure sensor 40 feeds back the instantaneous system pressure in the oil circuit to the controller 50.

[0101] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is greater than a first temperature value and equal to a second temperature value, the hydraulic oil displacement output by the variable pump 90 is greater than the minimum required flow rate of the second motor 80 and less than or equal to the maximum required flow rate of the second motor 80.

[0102] In a possible embodiment, when the instantaneous temperature indicated by the temperature parameter is equal to the second temperature value, the displacement of the variable pump 90 increases, and the outlet pressure of the variable pump 90 increases until the pressure sensor 40 detects that the instantaneous system pressure is equal to the second preset pressure.

[0103] In some possible embodiments of the present invention, the step of determining the adjustment strategy based on the minimum displacement of the variable pump 90 specifically includes:

[0104] Based on the minimum displacement of the variable pump 90, the hydraulic oil flows through the second directional valve 140 and the first directional valve 120, and then flows back to the oil tank 60.

[0105] In this configuration, the fan 21 of the radiator 20 is in a non-working state, and the fan 21 is connected in parallel with the second reversing valve 140.

[0106] Specifically, this embodiment provides an implementation method for determining the adjustment strategy based on the minimum displacement of the variable pump 90. When the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 140 is de-energized, the variable pump 90 outputs hydraulic oil according to the minimum displacement, the hydraulic oil flows through the second reversing valve 140, at this time the fan 21 of the radiator 20 does not work, and the hydraulic oil flows back to the oil tank 60 through the first reversing valve 120.

[0107] The present invention will now be described in detail with reference to specific embodiments.

[0108] In an application scenario, such as Figure 5 As shown, the calculation of the hydraulic circuit is as follows:

[0109] 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.

[0110] Furthermore, when the oil temperature in the oil tank 60 reaches T1, the minimum required power P2 (kW) of the fan 21 of the radiator 20 is achieved.

[0111] Furthermore, when the oil temperature in the tank reaches T2, the maximum power required by the fan 21 of the radiator 20 is P3 (kW).

[0112] Furthermore, the compressor 11 of the air conditioner 10 requires a constant power P4 (kW), and under normal excavator operating conditions, P3 > P2 > P4.

[0113] 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.

[0114] 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).

[0115] Furthermore, according to the power-speed curve of fan 21, when fan 21 reaches its maximum power P3 at speed n3 (r / min), the actual maximum power of the second motor 80 is: P 31 =P3*x2(kw).

[0116] 3. 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.

[0117] Furthermore, according to the power-speed curve of compressor 11, the speed n4 (r / min) reaches the power P4. The actual power of the first motor 70 is: P 41 =P4*x4(kw).

[0118] 4. Rated pressure p1 (MPa), rated displacement v1 (ml / r), rated speed n1 (r / min), and volumetric efficiency y1 of variable pump 90.

[0119] The rated power of variable pump 90 is: P1=p1*v1*n1 / (1000*60)=p1*v1*n1 / 60000(kw), which must satisfy the condition y1*P1>P 31 +P 41 .

[0120] 5. The second motor 80 driving the fan 21 of the radiator 20 has a relatively high 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 .

[0121] Furthermore, the hydraulic circuit flow rate Q of the second motor 80 is a variable value, requiring a minimum flow rate Q1 = v2*n2 / (y2*1000) (L / min), and the pressure difference p across the second motor 80. 21 =P 21 *60000 / (v2*n2)(Mpa).

[0122] Furthermore, the hydraulic circuit flow rate Q of the second motor 80 is a variable value, with a maximum required flow rate Q2 = v2*n3 / (y2*1000) (L / min). The pressure difference p across the second motor 80 is... 31 =P 31 *60000 / (v2*n2)(Mpa).

[0123] 6. At minimum flow rate in the hydraulic circuit, the power P of the second motor driving the compressor (11) should be sufficient. 41 The second motor's rotational speed n is 80. 41 =Q 1 / (v4*y4)=v2*n2 / (v4*y4*y2*1000)(r / min). Compressor 11 belt pulley transmission ratio i=n 41 / n4=v2*n2 / (n4*v4*y4*y2*1000). The pressure difference p across the two ends of the second motor 80 41 =P41 *60 / Q1=P4*x4*y2*60000 / v2*n2(Mpa).

[0124] 7. The pressure compensation for the flow valve 100 is set to p5. Select p5 and p 21 The proportional relationship is i1 = p 21 / p5≥10.

[0125] The pressure setting for flow valve 100 is p5 = p 21 / i1=P 21 *60000 / (v2*n2*i1)(Mpa).

[0126] 8. Calculation of the orifice area A0 of the flow valve 100, pipe diameter D (mm), hydraulic oil density ρ, and selection of the 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

[0127] 9. The set pressure values ​​for the first relief valve 110 and the second relief valve 130 in the hydraulic circuit are as follows: The set pressure of the first relief valve 110 is: p6 = p5 + p 41 (MPa), the set pressure of the second relief valve 130 is p7 = p6 + p 31 (MPa).

[0128] 10. Pressure sensor 40 detects the hydraulic circuit pressure value p≤p7, and the hydraulic circuit pressure calculation meets the condition: p7≤p1.

[0129] In some specific embodiments of the present invention, such as Figure 8 As shown, this solution provides a control device for a series hydraulic system of an excavator, comprising:

[0130] 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;

[0131] 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.

[0132] 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.

[0133] 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:

[0134] When the status parameter indicates that the compressor 11 is in the working state, the first reversing valve 120 is energized, wherein the first reversing valve 120 is connected in parallel with the first motor 70;

[0135] 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, a second preset pressure, and a third preset pressure. The first preset pressure is the sum of the first overflow pressure of the first relief valve 110 and the pressure difference between the two ends of the second motor 80 at the minimum required flow rate. The second preset pressure is the sum of the first overflow pressure of the first relief valve 110 and the pressure difference between the two ends of the second motor 80 at the maximum required flow rate. The third preset pressure is the first overflow pressure of the first relief valve 110.

[0136] The first overflow valve 110 is connected in parallel with the first motor 70 and in series with the second motor 80.

[0137] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

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

[0139] Based on the energization of the second reversing valve 140, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and 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.

[0140] If the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the second reversing valve 140 is de-energized, and the adjustment strategy is determined based on the instantaneous system pressure being equal to the third preset pressure.

[0141] The second reversing valve 140 and the second motor 80 are connected in parallel.

[0142] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and preset system pressure.

[0143] 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:

[0144] When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value, the displacement of the variable pump 90 increases until the instantaneous system pressure meets the preset system pressure. The displacement of the variable pump 90 is greater than the minimum required flow rate of the second motor 80 and less than or equal to the maximum required flow rate of the second motor 80.

[0145] When the instantaneous temperature indicated by the temperature parameter is lower than the first temperature value, the hydraulic oil delivered by the variable pump 90 flows sequentially through the second directional valve 140, the flow valve 100 and the first motor 70, and then flows back to the oil tank 60. The flow valve 100 is connected in series with the first motor 70, and the second motor 80 is in a non-working state.

[0146] Specifically, this embodiment provides an implementation method for adjusting the instantaneous system pressure in the oil circuit until a preset system pressure is met.

[0147] 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:

[0148] When the status parameter indicates that the compressor 11 is in a non-working state, the first reversing valve 120 is de-energized, wherein the first reversing valve 120 is connected in parallel with the first motor 70;

[0149] Based on temperature parameters, an adjustment strategy and preset system pressure are determined. The preset system pressure includes at least a fourth preset pressure and a fifth preset pressure. The fourth preset pressure is the pressure difference between the two ends of the second motor 80 at the minimum required flow rate, and the fifth preset pressure is the pressure difference between the two ends of the second motor 80 at the maximum required flow rate.

[0150] Specifically, this embodiment provides an implementation method for determining the regulation strategy of the regulating oil circuit and the preset system pressure.

[0151] Optionally, the steps of determining the regulation strategy and preset system pressure based on temperature parameters specifically include:

[0152] Based on the energization of the second reversing valve 140, when the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value and equal to the second temperature value, the adjustment strategy is determined based on the instantaneous system pressure being greater than the fourth preset pressure and less than or equal to the fifth preset pressure.

[0153] If the instantaneous temperature indicated by the temperature parameter is lower than the first temperature value, the second reversing valve 140 is de-energized, and the adjustment strategy is determined based on the minimum displacement of the variable pump 90.

[0154] The second reversing valve 140 and the second motor 80 are connected in parallel.

[0155] Specifically, this embodiment provides an implementation method for determining the adjustment strategy and preset system pressure.

[0156] Optionally, the step of determining the adjustment strategy based on the minimum displacement of the variable pump 90 specifically includes:

[0157] Based on the minimum displacement of the variable pump 90, the hydraulic oil flows through the second directional valve 140 and the first directional valve 120, and then flows back to the oil tank 60.

[0158] In this configuration, the fan 21 of the radiator 20 is in a non-working state, and the fan 21 is connected in parallel with the second reversing valve 140.

[0159] Specifically, this embodiment provides an implementation method for determining the adjustment strategy based on the minimum displacement of the variable pump 90.

[0160] In some specific embodiments of the present invention, such as Figures 2 to 8 As shown, this solution provides an excavator, including the aforementioned series hydraulic system for an excavator;

[0161] Alternatively, when controlling the hydraulic system of an excavator, the control method described above for a series hydraulic system of an excavator may be used.

[0162] Alternatively, it may include the control device for the series hydraulic system of an excavator as described above.

[0163] 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.

[0164] 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.

[0165] 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 series hydraulic system of an excavator, characterized in that, Applied to controllers; The system includes: 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, the second motor, and the variable pump are connected in series and respectively connected to the oil tank; the temperature sensor is connected to the oil tank; the controller is electrically connected to the variable pump, the temperature sensor, and the pressure sensor, respectively, for using one variable pump to achieve coordinated control of the air conditioner, the compressor, the radiator, and the fan. The method includes: Obtain the compressor's status parameters and the oil tank's temperature parameters; 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. Based on the aforementioned adjustment strategy, the instantaneous system pressure in the oil circuit is adjusted until the preset system pressure is met; 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: When the status parameter indicates that the compressor is in a working state, the first reversing valve is energized, wherein the first reversing valve is connected in parallel with the first motor; Based on the temperature parameters, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a first preset pressure, a second preset pressure, and a third preset pressure. The first preset pressure is the sum of the first overflow pressure of the first relief valve and the pressure difference between the two ends of the second motor at the minimum required flow rate. The second preset pressure is the sum of the first overflow pressure of the first relief valve and the pressure difference between the two ends of the second motor at the maximum required flow rate. The third preset pressure is the first overflow pressure of the first relief valve. The first overflow valve is connected in parallel with the first motor and in series with the second motor.

2. The control method for a series hydraulic system for an excavator according to claim 1, characterized in that, The system also includes: The first overflow valve is connected in parallel with the first motor and in series with the second motor; The first reversing valve is connected in parallel with the first motor and the first relief valve, and is connected in series with the second motor; The second overflow valve is connected in parallel with the second motor and in series with the first motor; The second reversing valve is connected in parallel with the second motor and the second relief valve, and is connected in series with the first motor. A flow valve is connected in series with the first motor.

3. The control method for a series hydraulic system for an excavator according to claim 1 or 2, characterized in that, The step of determining the adjustment strategy and the preset system pressure based on the temperature parameter specifically includes: 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 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. 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 third preset pressure. The second reversing valve is connected in parallel with the second motor.

4. The control method for a series hydraulic system for an excavator according to claim 3, characterized in that, The step of adjusting the instantaneous system pressure in the oil circuit according to the adjustment strategy until the preset system pressure is met further includes: When the instantaneous temperature indicated by the temperature parameter is greater than the first temperature value, the displacement of the variable pump increases until the instantaneous system pressure meets the preset system pressure, wherein the displacement of the variable pump is greater than the minimum flow rate required by the second motor and less than or equal to the maximum flow rate required by the second motor. When the instantaneous temperature indicated by the temperature parameter is less than the first temperature value, the hydraulic oil delivered by the variable pump flows sequentially through the second directional valve, the flow valve, and the first motor before returning to the oil tank. The flow valve is connected in series with the first motor, and the second motor is in a non-operating state.

5. The control method for a series hydraulic system for an excavator according to claim 1 or 2, characterized in that, 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: When the status parameter indicates that the compressor is in a non-working state, the first reversing valve is de-energized, wherein the first reversing valve is connected in parallel with the first motor; Based on the temperature parameter, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a fourth preset pressure and a fifth preset pressure. The fourth preset pressure is the pressure difference between the two ends when the second motor requires the minimum flow rate, and the fifth preset pressure is the pressure difference between the two ends when the second motor requires the maximum flow rate.

6. The control method for a series hydraulic system for an excavator according to claim 5, characterized in that, The step of determining the adjustment strategy and the preset system pressure based on the temperature parameter specifically includes: 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 equal to the second temperature value, the adjustment strategy is determined according to the instantaneous system pressure being greater than the fourth preset pressure and less than or equal to the fifth preset pressure. 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 according to the minimum displacement of the variable pump. The second reversing valve is connected in parallel with the second motor.

7. The control method for a series hydraulic system for an excavator according to claim 6, characterized in that, The step of determining the adjustment strategy based on the minimum displacement of the variable pump specifically includes: Based on the minimum displacement of the variable pump, the hydraulic oil flows through the second directional valve and the first directional valve, and then flows back to the oil tank. The radiator fan is in a non-working state, and the fan is connected in parallel with the second reversing valve.

8. A control device for a series hydraulic system of an excavator, characterized in that, Applied to controllers; The system includes: 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, the second motor, and the variable pump are connected in series and respectively connected to the oil tank; the temperature sensor is connected to the oil tank; the controller is electrically connected to the variable pump, the temperature sensor, and the pressure sensor, respectively, for using one variable pump to achieve coordinated control of the air conditioner, the compressor, the radiator, and the fan. The device includes: The parameter acquisition module is used to acquire the compressor's status parameters and the oil tank's temperature parameters. 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. 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; 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: When the status parameter indicates that the compressor is in a working state, the first reversing valve is energized, wherein the first reversing valve is connected in parallel with the first motor; Based on the temperature parameters, the adjustment strategy and the preset system pressure are determined. The preset system pressure includes at least a first preset pressure, a second preset pressure, and a third preset pressure. The first preset pressure is the sum of the first overflow pressure of the first relief valve and the pressure difference between the two ends of the second motor at the minimum required flow rate. The second preset pressure is the sum of the first overflow pressure of the first relief valve and the pressure difference between the two ends of the second motor at the maximum required flow rate. The third preset pressure is the first overflow pressure of the first relief valve. The first overflow valve is connected in parallel with the first motor and in series with the second motor.

9. An excavator, characterized in that, include When performing hydraulic system control of an excavator, the control method for a series hydraulic system of an excavator as described in any one of claims 1 to 7 is adopted; Alternatively, it may include the control device for the series hydraulic system of an excavator as described in claim 8.

Images