Excavator swing motor, hydraulic system, and control method

Abstract

The application provides a kind of excavator rotary motor, hydraulic system and control method, the structure of excavator rotary motor includes motor main body, is provided with first oil port and second oil port;First check valve, communication in first oil port and the oil tank of excavator;Second check valve, communication in second oil port and the oil tank of excavator;First adjustable overflow valve, communication in first oil port and second check valve;Second adjustable overflow valve, communication in second oil port and first check valve;Proportional pressure reducing valve, communication in the pilot port of first adjustable overflow valve and the pilot port of second adjustable overflow valve, proportional pressure reducing valve is communicated in oil tank;And control detection part, connected to motor main body, control detection part is electrically connected with proportional pressure reducing valve.This excavator rotary motor, hydraulic system and control method can solve the problem that existing excavator rotary motor is difficult to realize constant pressure starting and constant pressure braking due to the influence of temperature and flow.

Description

Technical Field

[0001] This application relates to the field of excavator technology, and in particular to an excavator swing motor, hydraulic system and control method. Background Technology

[0002] The slewing motor is the power component that enables an excavator to rotate, driving the slewing bearing to achieve the excavator's slewing function. Existing slewing motors typically use a constant relief valve. While a constant relief valve can provide starting and braking torque to the slewing motor, the relief pressure cannot be adjusted.

[0003] Furthermore, due to the inherent characteristics of the constant relief valve, the relief pressure is significantly affected by the flow rate; the higher the flow rate, the higher the relief pressure, and vice versa. This results in lower flow rates from the main pump to the system when the excavator is in low gear, leading to lower relief pressure from the swing motor and lower starting and braking torques than the ideal settings. Moreover, the actual starting and braking torques of the swing motor differ across different gears.

[0004] Furthermore, due to the characteristics of the relief valve and the hydraulic oil itself, the viscosity of the hydraulic oil increases in low-temperature environments. This significantly affects the starting pressure of the swing motor, causing the apparent relief pressure to often exceed the set value. The relief valve's function as a system protection mechanism diminishes, leading to excessive torque during startup. Exceeding the limit on swing torque not only damages the swing motor but also increases the burden on structural components, reducing their lifespan and potentially causing complete structural failure. Conversely, in high-temperature environments, the viscosity of the hydraulic oil decreases, the actual relief pressure weakens, and the starting and braking torque of the swing motor decreases, resulting in longer starting and braking times and ultimately reducing the excavator's working efficiency. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide an excavator swing motor, hydraulic system and control method to solve the problem that existing excavator swing motors are difficult to achieve constant pressure start and constant pressure braking due to the influence of temperature and flow.

[0006] According to a first aspect of the present invention, an excavator swing motor is provided, wherein the excavator swing motor comprises: a motor body having a first oil port and a second oil port, the first oil port being connected to a first cavity of the motor body and the second oil port being connected to a second cavity of the motor body; a first check valve being connected to the first oil port and the excavator's oil tank; a second check valve being connected to the second oil port and the excavator's oil tank; a first adjustable relief valve being connected to the first oil port and the second check valve; a second adjustable relief valve being connected to the second oil port and the first check valve; a proportional pressure reducing valve being connected to a pilot oil port of the first adjustable relief valve and a pilot oil port of the second adjustable relief valve, the proportional pressure reducing valve being capable of outputting a pilot pressure to the first adjustable relief valve and the second adjustable relief valve, the proportional pressure reducing valve being connected to the oil tank; and a control detection unit connected to the motor body, the control detection unit being capable of detecting the pressure of the first oil port and the second oil port, the control detection unit being electrically connected to the proportional pressure reducing valve, and the control detection unit being capable of controlling the pilot pressure output by the proportional pressure reducing valve.

[0007] Preferably, the control and detection unit includes: a processor electrically connected to the proportional pressure reducing valve, the processor being capable of controlling the pilot pressure output by the proportional pressure reducing valve; a first pressure sensor installed at the pressure measuring port of the motor body, the first pressure sensor being used to detect the pressure of the first oil port, the first pressure sensor being electrically connected to the processor; and a second pressure sensor installed at the pressure measuring port of the motor body, the second pressure sensor being used to detect the pressure of the second oil port, the first pressure sensor being electrically connected to the processor.

[0008] According to a second aspect of the invention, a hydraulic system is provided, wherein the hydraulic system includes an excavator swing motor as described above.

[0009] Preferably, the hydraulic system further includes: a slewing valve connected to the oil tank, with the first oil port and the second oil port connected to the slewing valve, and the processor electrically connected to the slewing valve; a main pump connected to the slewing valve for supplying oil to the slewing valve; and a pilot pump connected to the proportional pressure reducing valve.

[0010] Preferably, the directional valve is equipped with a first electromagnet and a second electromagnet. When the first electromagnet is energized, the hydraulic oil in the directional valve can flow into the first chamber through the first oil port. When the second electromagnet is energized, the hydraulic oil in the directional valve can flow into the second chamber through the second oil port. The processor is electrically connected to the first electromagnet and the second electromagnet respectively, and is used to detect the energization status of the first electromagnet and the second electromagnet.

[0011] Preferably, the first check valve and the second check valve are connected to the oil tank through a first pipeline, and the first pipeline is equipped with a back pressure valve.

[0012] According to a third aspect of the present invention, a control method for a hydraulic system is provided, wherein the hydraulic system is as described above, and the control method for the hydraulic system includes: achieving constant pressure start-up and constant pressure braking of the excavator swing motor by controlling the energization of the first electromagnet and the second electromagnet and the pilot pressure output by the proportional pressure reducing valve.

[0013] Preferably, the target overflow pressure value of the motor body is set to P, the base pressure value of the first adjustable overflow valve or the second adjustable overflow valve is Pp, the pressure gain brought by the pilot pressure output by the proportional pressure reducing valve is ΔP, and the processor adjusts the pilot pressure output by the proportional pressure reducing valve in real time according to the detection result of the first pressure sensor or the second pressure sensor, so that P = Pp + ΔP.

[0014] Preferably, the detection result of the first pressure sensor or the second pressure sensor is P'. When the processor determines that P' is not equal to P, the processor outputs a current value I to the proportional pressure reducing valve to adjust the pilot pressure output by the proportional pressure reducing valve.

[0015] Preferably, after the excavator swing motor has started, the processor keeps the output current value I of the proportional pressure reducing valve unchanged, ensuring that the excavator swing motor has the same overflow pressure during braking as it does during startup.

[0016] The excavator swing motor, hydraulic system, and control method of this invention include a motor body with a first oil port and a second oil port. The first oil port is connected to a first chamber of the motor body, and the second oil port is connected to a second chamber of the motor body. A first check valve is connected to the first oil port and the excavator's oil tank, and a second check valve is connected to the second oil port and the excavator's oil tank. A first adjustable relief valve is connected to the first oil port and the second check valve, and a second adjustable relief valve is connected to the second oil port and the first check valve. A proportional pressure reducing valve is connected to the pilot oil ports of the first and second adjustable relief valves, and the proportional pressure reducing valve can output pilot pressure to the first and second adjustable relief valves. The proportional pressure reducing valve is connected to the oil tank. A control detection unit is connected to the motor body and can detect the pressure of the first and second oil ports. Furthermore, the control detection unit is electrically connected to the proportional pressure reducing valve and can control the pilot pressure output by the proportional pressure reducing valve. Therefore, the control and detection unit can adjust the pilot pressure output of the proportional pressure reducing valve in real time based on the pressure changes detected by the first and second oil ports. This pilot pressure compensates for the changes in overflow pressure of the first and second adjustable overflow valves due to temperature or flow variations, thereby achieving constant pressure start-up and constant pressure braking of the excavator's swing motor. This effectively solves the problem that existing excavator swing motors are difficult to use for constant pressure start-up and constant pressure braking due to the influence of temperature and flow.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the hydraulic system according to the present invention.

[0020] Figure 2 This is a flowchart of a control method for a hydraulic system according to the present invention.

[0021] Figure 3 This is a schematic diagram of another embodiment of the hydraulic system according to the present invention.

[0022] Figure 4 This is a flowchart of another embodiment of the control method for a hydraulic system according to the present invention.

[0023] Reference numerals: 1-Motor body; 11-First oil port; 12-Second oil port; 21-First check valve; 22-Second check valve; 31-First adjustable relief valve; 32-Second adjustable relief valve; 4-Proportional pressure reducing valve; 50-Processor; 51-First pressure sensor; 52-Second pressure sensor; 6-Reversing valve; 61-First electromagnet; 62-Second electromagnet; 71-Main pump; 72-Pilot pump; 8-Back pressure valve; 80-First pipeline; 9-Oil tank. Detailed Implementation

[0024] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0025] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0026] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0027] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0028] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0029] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0030] The terminology used herein is for the purpose of describing various examples only and is not intended to limit the examples. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0031] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0032] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0033] like Figures 1 to 4As shown, according to a first aspect of the present invention, an excavator swing motor is provided, the excavator swing motor including a motor body 1, a first one-way valve 21, a second one-way valve 22, a first adjustable relief valve 31, a second adjustable relief valve 32, a proportional pressure reducing valve 4, and a control and detection unit.

[0034] In the following description, reference will be made to Figures 1 to 4 The specific structure of the aforementioned components of the excavator's swing motor and their connection relationships are described in detail.

[0035] like Figure 1 As shown, in this embodiment, the motor body 1 may be provided with a first oil port 11 and a second oil port 12, the first oil port 11 and the second oil port 12 being used for oil inlet and oil return, respectively. The first oil port 11 may be connected to the first cavity of the motor body 1 (e.g., Figure 1 As shown, the first cavity can be located on the left side of the motor body 1, and the second oil port 12 can be connected to the second cavity of the motor body 1 (e.g., Figure 1 As shown, the second chamber can be located on the right side of the motor body 1. The first check valve 21 can be connected to the first oil port 11 and the excavator's oil tank 9, and the second check valve 22 can be connected to the second oil port 12 and the excavator's oil tank 9. The first check valve 21 and the second check valve 22 can replenish oil to the low-pressure chamber of the motor body 1 when the motor is braking. The first adjustable relief valve 31 can be connected to the first oil port 11 and the second check valve 22. The second adjustable relief valve 32 can be connected to the second oil port 12 and the first check valve 21. The proportional pressure reducing valve 4 can be connected to the pilot oil port of the first adjustable relief valve 31 and the pilot oil port of the second adjustable relief valve 32. The proportional pressure reducing valve 4 can output pilot pressure to the first adjustable relief valve 31 and the second adjustable relief valve 32 to adjust the overflow pressure of the first adjustable relief valve 31 and the second adjustable relief valve 32. The proportional pressure reducing valve 4 is connected to the oil tank 9. The control and detection unit can be connected to the motor body 1. The control and detection unit can detect the pressure of the first oil port 11 and the second oil port 12 in real time. Additionally, the control and detection unit can be electrically connected to the proportional pressure reducing valve 4. The control and detection unit can control the pilot pressure output by the proportional pressure reducing valve 4. Therefore, the control and detection unit can adjust the pilot pressure output by the proportional pressure reducing valve 4 in real time based on the changes in the pressure values ​​detected by the first oil port 11 and the second oil port 12, and compensate for the changes in the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32 due to temperature or flow rate changes, thereby achieving constant pressure start-up and constant pressure braking of the excavator's swing motor.

[0036] Preferred, such as Figure 1 and Figure 2As shown, in this embodiment, the control and detection unit may include a processor 50, a first pressure sensor 51, and a second pressure sensor 52. The processor 50 may be located outside the housing of the excavator's rotary motor, and may be the excavator's overall processor. The processor 50 may be electrically connected to the proportional pressure reducing valve 4, and the processor 50 can control the magnitude of the pilot pressure output by the proportional pressure reducing valve 4 through its output current value. The proportional pressure reducing valve 4 may be a direct proportional valve or an inverse proportional valve. More preferably, in this embodiment, the proportional pressure reducing valve 4 may be a direct proportional valve. This ensures that when the current value output by the processor 50 increases, the pilot pressure output by the proportional pressure reducing valve 4 increases; and when the current value output by the processor 50 decreases, the pilot pressure output by the proportional pressure reducing valve 4 decreases. The first pressure sensor 51 and the second pressure sensor 52 may be installed at the pressure measuring port of the motor body 1. The first pressure sensor 51 is used to detect the pressure of the first oil port 11 in real time, and the second pressure sensor 52 is used to detect the pressure of the second oil port 12 in real time. The first pressure sensor 51 and the second pressure sensor 52 are electrically connected to the processor 50, thereby feeding back an electrical signal to the processor 50. The processor 50 can then control the proportional pressure reducing valve 4 based on the received electrical signal value. Preferably, the conductive connection can be achieved through a wire to transmit the electrical signal.

[0037] During operation, the first pressure sensor 51 and the second pressure sensor 52 detect the pressure at the first oil port 11 and the second oil port 12 of the motor body 1, respectively. When the excavator's swing motor starts and brakes, the first pressure sensor 51 and the second pressure sensor 52 convert the pressure signals into electrical signals and feed them back to the processor 50. The processor 50 outputs different electrical signals based on the detected pressure values ​​of the first and second chambers of the motor body 1 to control the proportional pressure reducing valve 4. Upon receiving the electrical signals, the proportional pressure reducing valve 4 can output different pilot pressures to control the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32, ultimately stabilizing the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32 at set values, thereby maintaining stable starting and braking torques of the excavator's swing motor.

[0038] Not limited to this, in such Figure 3In another embodiment shown, the processor 50 can be directly connected to the first adjustable overflow valve 31 and the second adjustable overflow valve 32 via wires. In this case, the first adjustable overflow valve 31 and the second adjustable overflow valve 32 are electrically controlled valves. The processor 50 controls the opening degree of the first adjustable overflow valve 31 and the second adjustable overflow valve 32 through electrical signals, thereby directly controlling the pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32, ultimately stabilizing the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32 at a set value, and keeping the starting torque and braking torque of the excavator's swing motor stable.

[0039] In addition, such as Figure 1 and Figure 3 As shown, according to a second aspect of the present invention, a hydraulic system is provided, the hydraulic system comprising an excavator swing motor as described above.

[0040] Preferred, such as Figure 1 As shown, in this embodiment, the hydraulic system may further include a directional control valve 6, a main pump 71, and a pilot pump 72. The directional control valve 6 can be connected to the excavator's oil tank 9. The first oil port 11 and the second oil port 12 of the motor body 1 can be connected to the directional control valve 6. This allows hydraulic oil to flow into the motor body 1 through the directional control valve 6, and hydraulic oil in the motor body 1 can also flow out to the directional control valve 6. The directional control valve 6 can also be electrically connected to the processor 50 for transmitting electrical signals. The main pump 71 can be connected to the directional control valve 6 to supply oil to it. The pilot pump 72 can be connected to the proportional pressure reducing valve 4, and the pilot pump 72 can be connected in series with the main pump 71. Additionally, in... Figure 3 In the embodiment shown, since the processor 50 is directly connected to the first adjustable overflow valve 31 and the second adjustable overflow valve 32 via wires, there is no need to install a pilot pump 72.

[0041] Preferred, such as Figure 1 and Figure 3As shown, in this embodiment, the slewing valve 6 may be equipped with a first electromagnet 61 and a second electromagnet 62. When the first electromagnet 61 is energized, hydraulic oil in the slewing valve 6 flows into the first chamber through the first oil port 11 of the motor body 1, and the excavator's slewing motor starts clockwise. When the first electromagnet 61 is de-energized and returns to the neutral position, the motor body 1 brakes clockwise. When the second electromagnet 62 is energized, hydraulic oil in the slewing valve 6 flows into the second chamber through the second oil port 12 of the motor body 1, and the excavator's slewing motor starts counterclockwise. When the second electromagnet 62 is de-energized and returns to the neutral position, the motor body 1 brakes counterclockwise. The processor 50 can be electrically connected to the first electromagnet 61 and the second electromagnet 62 respectively, thereby enabling real-time control of the energization and de-energization of the first electromagnet 61 and the second electromagnet 62 to determine the starting and braking status of the excavator's slewing motor.

[0042] In addition, preferred, such as Figure 1 and Figure 3 As shown, in this embodiment, the first check valve 21 and the second check valve 22 can be connected to the oil tank 9 via the first pipeline 80. Specifically, a back pressure valve 8 can be installed on the first pipeline 80. The back pressure valve 8 can cooperate with the first check valve 21 and the second check valve 22 to allow the excavator's swing motor to replenish oil to the low-pressure chamber of the motor body 1 when braking.

[0043] During operation, the main pump 71 supplies oil to the motor body 1. The slewing valve 6 controls the steering, starting, and braking of the motor body 1. The processor 50 determines the starting and braking status of the excavator's slewing motor based on the energization and de-energization of the first electromagnet 61 and the second electromagnet 62 of the slewing valve 6, and outputs an electrical signal to control the proportional pressure reducing valve 4. This controls the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32, ensuring that the starting and braking pressures of the excavator's slewing motor remain constant.

[0044] In addition, such as Figure 1 and Figure 2 As shown, according to a third aspect of the present invention, a control method for a hydraulic system is provided, wherein the hydraulic system is a hydraulic system as described above (i.e., as...). Figure 1 (The hydraulic system shown). The control method of the hydraulic system includes: controlling the energization of the first electromagnet 61 and the second electromagnet 62 and the pilot pressure output by the proportional pressure reducing valve 4 to achieve constant pressure start-up and constant pressure braking of the excavator's swing motor.

[0045] Preferred, such as Figure 1 and Figure 2As shown, in this embodiment, the target overflow pressure value of the motor body 1 can be set to P. The base pressure value of the first adjustable overflow valve 31 or the second adjustable overflow valve 32 without pilot pressure is Pp (i.e., primary pressure). Due to the characteristics of the overflow valve itself, the primary pressure will change with changes in flow rate and temperature. The pressure gain brought by the pilot pressure output by the proportional pressure reducing valve 4 is ΔP (i.e., secondary pressure), and the secondary pressure is a variable pressure that can be adjusted in real time. The processor 50 can adjust the pilot pressure output by the proportional pressure reducing valve 4 in real time according to the detection results of the first pressure sensor 51 or the second pressure sensor 52. Finally, the target overflow pressure value P = Pp + ΔP is made, that is, the secondary pressure is adjusted in real time according to the change value of the primary pressure to correct and compensate the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32, so that the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32 can be stabilized at the target overflow pressure value P. This ensures that the starting pressure and braking pressure of the excavator's rotary motor remain constant even at different gears and temperatures.

[0046] Furthermore, preferably, such as Figure 1 and Figure 2 As shown, in this embodiment, the detection result of the first pressure sensor 51 or the second pressure sensor 52 can be P' (i.e., the detection value of the first oil port 11 or the second oil port 12 of the motor body 1). When the processor 50 determines that P' is not equal to P, the processor 50 will output a current value I to the proportional pressure reducing valve 4 to adjust the pilot pressure value Pi output by the proportional pressure reducing valve 4. When the pilot pressure value Pi increases, the secondary pressure ΔP increases. When the pilot pressure value Pi decreases, the secondary pressure ΔP decreases.

[0047] Further optimized, such as Figure 1 and Figure 2 As shown in the embodiment, after the excavator swing motor has started, the processor 50 can keep the current value I output to the proportional pressure reducing valve 4 unchanged to ensure that the excavator swing motor has the same overflow pressure during braking as it does during startup.

[0048] During the operation of the hydraulic system, the measured value of the primary pressure Pp will change when the temperature or flow rate changes (e.g., the gear position changes). Under the same temperature conditions, due to the characteristics of the relief valve itself, the measured value of Pp will decrease when the input flow rate of the motor body 1 decreases, and increase when the input flow rate of the motor body 1 increases. Under the same flow rate conditions, the measured value of Pp will decrease when the temperature increases and the viscosity of the hydraulic oil decreases, and increase when the temperature decreases and the viscosity of the hydraulic oil increases. When the first pressure sensor 51 or the second pressure sensor 52 detects that the pressure value P' of the first oil port 11 or the second oil port 12 of the motor body 1 is no longer equal to the target relief pressure value P, the secondary pressure ΔP can be adjusted in real time to compensate for the change in the primary pressure Pp. That is, when the primary pressure Pp decreases, the processor 50 can control the pilot pressure value Pi output by the proportional pressure reducing valve 4 to increase, thereby increasing the secondary pressure ΔP. When the primary pressure Pp increases, the processor 50 can control the pilot pressure Pi output by the proportional pressure reducing valve 4 to decrease, thereby reducing the secondary pressure ΔP. This ensures that the compensation amount of ΔP equals the change in Pp, ultimately achieving constant overflow pressure in the motor body 1, enabling the excavator's swing motor to start and brake under constant pressure.

[0049] Specifically, such as Figure 2 As shown, taking the proportional pressure reducing valve 4 as an example of a direct proportional pressure reducing valve, the process of the excavator's swing motor starting clockwise at different gears is as follows.

[0050] In this embodiment, the main pump 71 provides flow to the hydraulic system. When the first electromagnet 61 of the directional valve 6 is energized, hydraulic oil enters the first port 11 of the motor body 1 through the directional valve 6, driving the motor body 1 to rotate clockwise. At this time, the processor 50 determines that the motor body 1 is starting clockwise and inputs a current value I0 to the proportional pressure reducing valve 4. The proportional pressure reducing valve 4 outputs a pilot pressure Pi acting on the first adjustable relief valve 31. Ideally, the relief pressure of the motor body 1 is P = Pp + ΔP.

[0051] When the flow rate changes, affected by the characteristics of the overflow valve itself, the value of Pp changes, and at the same time, the value of P also changes accordingly. The processor 50 adjusts the pilot pressure value output by the proportional pressure reducing valve 4, and then adjusts the value of △P, and finally keeps the value of P unchanged. For example: when switching to the low gear, the flow rate input to the first chamber of the motor main body 1 decreases, and the primary pressure Pp of the first adjustable overflow valve 31 drops to Pp1, Pp1 < Pp. At the same time, the overflow pressure of the motor main body 1 drops to P1. The first pressure sensor 51 detects the pressure value P1 and transmits it to the processor 50. The processor 50 adjusts the current value input to the proportional pressure reducing valve 4 to I1, I1 > I0 (that is, the current value input to the proportional pressure reducing valve 4 increases). At this time, the pilot pressure value output by the proportional pressure reducing valve 4 is Pi1, Pi1 > Pi. The pressure gain brought by the pilot pressure is △P1, △P1 > △P. Finally, Pp + △P = Pp1 + △P1 = P, achieving a constant overflow pressure when the excavator swing motor starts. Since the overflow pressure of the excavator swing motor is calibrated at the maximum flow rate of the excavator, there is generally no situation of exceeding the flow limit, that is, there is generally no situation where the overflow pressure increases due to excessive flow rate, which will not be elaborated here.

[0052] As Figure 2 shown, taking the proportional pressure reducing valve 4 as a proportional pressure reducing valve as an example, the process of the excavator swing motor starting clockwise at different temperatures is as follows.

[0053] In the embodiment, when the motor main body 1 starts clockwise in a low-temperature environment, due to the increase in the viscosity of the hydraulic oil, the primary pressure Pp of the first adjustable overflow valve 31 rises to Pp2, Pp2 > Pp. At the same time, the overflow pressure of the motor main body 1 rises to P2. The first pressure sensor 51 detects the pressure value P2 and transmits it to the processor 50. The processor 50 adjusts the current value input to the proportional pressure reducing valve 4 to I2, I2 < I0 (that is, the current value input to the proportional pressure reducing valve 4 decreases). At this time, the pilot pressure value output by the proportional pressure reducing valve 4 is Pi2, Pi2 < Pi. The pressure gain brought by the pilot pressure is △P2, making △P2 < △P. Finally, Pp + △P = Pp2 + △P2 = P, achieving a constant overflow pressure when the excavator swing motor starts. A high-temperature environment will cause the primary pressure Pp of the first adjustable overflow valve 31 to drop, and the adjustment process is similar to the above process, which will not be elaborated here.

[0054] In this embodiment, when the excavator's swing motor is braked clockwise, the first electromagnet 61 of the swing reversing valve 6 is de-energized, and the second adjustable relief valve 32 provides braking torque to the motor body 1. Since the first adjustable relief valve 31 provides torque to the motor body 1 when the excavator's swing motor starts clockwise, the first adjustable relief valve 31 and the second adjustable relief valve 32 share a pilot signal. After the excavator's swing motor starts, the excavator's handle returns to center, and the processor 50 controls the current value I input to the proportional pressure reducing valve 4 to remain constant, consistent with the current value I during startup. This ensures that the pilot pressure Pi acting on the first adjustable relief valve 31 and the second adjustable relief valve 32 remains constant. Consequently, during braking, the motor body 1 has the same primary pressure Pp and secondary pressure ΔP as during startup, thus ensuring that the excavator's swing motor has the same relief pressure during braking as during startup.

[0055] In addition, such as Figure 3 and Figure 4 As shown, in another embodiment of the control method for a hydraulic system, the hydraulic system is as follows: Figure 3 The hydraulic system shown is described. The control method of the hydraulic system includes: controlling the energization of the first electromagnet 61 and the second electromagnet 62, as well as the pressure of the first adjustable relief valve 31 and the second adjustable relief valve 32, to achieve constant pressure start-up and constant pressure braking of the excavator's swing motor.

[0056] Specifically, similar to the above embodiments, the target overflow pressure value of the motor body 1 can be set to P. The base pressure value of the first adjustable overflow valve 31 or the second adjustable overflow valve 32 is Pp (i.e., the first-level pressure). Due to the characteristics of the overflow valve itself, the first-level pressure will change due to changes in flow rate and temperature. The first adjustable overflow valve 31 and the second adjustable overflow valve 32 are affected by the current value I' input by the processor 50, resulting in a pressure gain of ΔP (i.e., the second-level pressure), which is a variable pressure that can be adjusted in real time. The processor 50 can adjust the second-level pressure ΔP in real time according to the detection results of the first pressure sensor 51 or the second pressure sensor 52. Finally, the target overflow pressure value P = Pp + ΔP is achieved, that is, the second-level pressure is adjusted in real time according to the change value of the first-level pressure to correct and compensate for the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32, so that the overflow pressure of the first adjustable overflow valve 31 and the second adjustable overflow valve 32 can be stabilized at the target overflow pressure value P. This ensures that the starting pressure and braking pressure of the excavator's rotary motor remain constant even at different gears and temperatures.

[0057] Furthermore, preferably, such as Figure 3 and Figure 4As shown, in this embodiment, the detection result of the first pressure sensor 51 or the second pressure sensor 52 can be P' (i.e., the detection value of the first oil port 11 or the second oil port 12 of the motor body 1). When the processor 50 determines that P' is not equal to P, the processor 50 will output a current value I' to the first adjustable relief valve 31 and the second adjustable relief valve 32 to adjust the secondary pressure ΔP.

[0058] During the operation of the hydraulic system, the measured value of the primary pressure Pp will change when the temperature or flow rate changes (e.g., the gear position changes). Under the same temperature conditions, due to the characteristics of the relief valve itself, the measured value of Pp will decrease when the input flow rate of the motor body 1 decreases, and increase when the input flow rate of the motor body 1 increases. Under the same flow rate conditions, the measured value of Pp will decrease when the temperature increases and the viscosity of the hydraulic oil decreases, and increase when the temperature decreases and the viscosity of the hydraulic oil increases. When the first pressure sensor 51 or the second pressure sensor 52 detects that the pressure value P' of the first oil port 11 or the second oil port 12 of the motor body 1 is no longer equal to the target relief pressure value P, the secondary pressure ΔP can be adjusted in real time to compensate for the change in the primary pressure Pp. That is, when the primary pressure Pp decreases, the processor 50 can control the input I' of the first adjustable relief valve 31 and the second adjustable relief valve 32 to increase, thereby increasing the secondary pressure ΔP. When the primary pressure Pp increases, the processor 50 can control the input I' of the first adjustable relief valve 31 and the second adjustable relief valve 32 to decrease, thereby reducing the secondary pressure ΔP. This ensures that the compensation amount of ΔP equals the change in Pp, ultimately achieving constant overflow pressure in the motor body 1, enabling the excavator's swing motor to start and brake under constant pressure.

[0059] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, 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 this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A swing motor for an excavator, installed in an excavator, characterized in that, The excavator swing motor includes: The motor body (1) is provided with a first oil port (11) and a second oil port (12). The first oil port (11) is connected to the first cavity of the motor body (1), and the second oil port (12) is connected to the second cavity of the motor body (1). The first check valve (21) is connected to the first oil port (11) and the oil tank (9) of the excavator. The second check valve (22) is connected to the second oil port (12) and the oil tank (9) of the excavator. The first adjustable relief valve (31) is connected to the first oil port (11) and the second check valve (22). The second adjustable relief valve (32) is connected to the second oil port (12) and the first check valve (21). A proportional pressure reducing valve (4) is connected to the pilot port of the first adjustable relief valve (31) and the pilot port of the second adjustable relief valve (32). The proportional pressure reducing valve (4) can output pilot pressure to the first adjustable relief valve (31) and the second adjustable relief valve (32). The proportional pressure reducing valve (4) is connected to the oil tank (9). The control detection unit is connected to the motor body (1). The control detection unit can detect the pressure of the first oil port (11) and the second oil port (12). The control detection unit is electrically connected to the proportional pressure reducing valve (4). The control detection unit can control the pilot pressure output by the proportional pressure reducing valve (4). The control and detection unit includes: The processor (50) is electrically connected to the proportional pressure reducing valve (4), and the processor (50) is capable of controlling the pilot pressure output by the proportional pressure reducing valve (4); A first pressure sensor (51) is used to detect the pressure of the first oil port (11), and the first pressure sensor (51) is electrically connected to the processor (50); and The second pressure sensor (52) is used to detect the pressure of the second oil port (12), and the second pressure sensor (52) is electrically connected to the processor (50).

2. The excavator swing motor according to claim 1, characterized in that, The first pressure sensor (51) is installed at a pressure measuring port of the motor body (1); The second pressure sensor (52) is installed at another pressure port of the motor body (1).

3. A hydraulic system, characterized in that, The hydraulic system includes the excavator swing motor as described in claim 2.

4. The hydraulic system according to claim 3, characterized in that, The hydraulic system also includes: A reversing valve (6) is connected to the oil tank (9), the first oil port (11) and the second oil port (12) are connected to the reversing valve (6), and the processor (50) is electrically connected to the reversing valve (6); The main pump (71), connected to the directional valve (6), is used to supply oil to the directional valve (6); and A pilot pump (72) is connected to the proportional pressure reducing valve (4).

5. The hydraulic system according to claim 4, characterized in that, The directional valve (6) is equipped with a first electromagnet (61) and a second electromagnet (62). When the first electromagnet (61) is energized, the hydraulic oil in the directional valve (6) can flow into the first chamber through the first oil port (11). When the second electromagnet (62) is energized, the hydraulic oil in the directional valve (6) can flow into the second chamber through the second oil port (12). The processor (50) is electrically connected to the first electromagnet (61) and the second electromagnet (62) respectively, and is used to detect the energization status of the first electromagnet (61) and the second electromagnet (62).

6. The hydraulic system according to claim 5, characterized in that, The first check valve (21) and the second check valve (22) are connected to the oil tank (9) through the first pipeline (80), and the first pipeline (80) is equipped with a back pressure valve (8).

7. A control method for a hydraulic system, characterized in that, The hydraulic system is the hydraulic system of claim 6, and the control method of the hydraulic system includes: controlling the energization of the first electromagnet (61) and the second electromagnet (62) and the pilot pressure output by the proportional pressure reducing valve (4) to realize constant pressure start and constant pressure braking of the excavator swing motor.

8. The control method for a hydraulic system according to claim 7, characterized in that, The target overflow pressure value of the motor body (1) is set to P, the base pressure value of the first adjustable overflow valve (31) or the second adjustable overflow valve (32) is Pp, the pressure gain brought by the pilot pressure output by the proportional pressure reducing valve (4) is ΔP, and the processor (50) adjusts the pilot pressure output by the proportional pressure reducing valve (4) in real time according to the detection result of the first pressure sensor (51) or the second pressure sensor (52) so that P=Pp+ΔP.

9. The control method for a hydraulic system according to claim 8, characterized in that, The detection result of the first pressure sensor (51) or the second pressure sensor (52) is P'. When the processor (50) determines that P' is not equal to P, the processor (50) outputs a current value I to the proportional pressure reducing valve (4) to adjust the pilot pressure output by the proportional pressure reducing valve (4).

10. The control method for a hydraulic system according to claim 9, characterized in that, After the excavator swing motor is started, the processor (50) keeps the output current value I of the proportional pressure reducing valve (4) unchanged, ensuring that the excavator swing motor has the same overflow pressure when braking as when starting.

Images