A plunger pump, a hydraulic system and a fault response control method thereof

Abstract

The present invention relates to the technical field of plunger pumps, and in particular, to a plunger pump, a hydraulic system and a fault response control method thereof. The plunger pump includes a pump body, an outlet switch valve, a pressure feedback valve, a unloading valve, a signal receiving valve and a fault detector. The pump body includes a housing, a swash plate, a rotor and a plunger. The housing has a first oil outlet and an oil return port. The outlet switch valve controls the opening and closing of the first oil outlet. The pressure feedback valve adjusts the tilt angle of the swash plate according to the magnitude of the load. The signal receiving valve controls the connection of the first oil outlet or the oil return port to the hydraulic control port and the inlet of the unloading valve. When the first oil outlet is connected to the hydraulic control port and the unloading valve, the first oil outlet closes and the unloading valve opens, and the tilt angle of the swash plate is adjusted to 0; when the oil return port is connected to the hydraulic control port and the unloading valve, the first oil outlet opens and the unloading valve closes. The hydraulic system includes a plunger pump. The fault response method is applied to the hydraulic system. In this way, the problem of oil pollution diffusion caused by the failure of the plunger pump is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of plunger pumps, and in particular, to a plunger pump, a hydraulic system and a fault response control method thereof. Background Art

[0002] As the core power component of a hydraulic system, the main hydraulic pump's core function is to continuously output hydraulic energy that meets the system's required pressure and flow rate. When the main hydraulic pump suffers from wear and tear failures, the pollutants generated by mechanical wear of the moving pairs inside the main hydraulic pump will enter the hydraulic system pipeline along with the output oil. When these pollutants flow through precision accessories such as hydraulic control valves, they may cause progressive damage such as surface scratches and seal failures of key components. More seriously, when the pollution particles accumulate at the hydraulic system filter and cause abnormal pressure difference in the return oil pipeline, it will trigger the abnormal opening of the system return oil safety valve, resulting in the reverse flow of the contaminated oil containing wear products back to the hydraulic oil tank, causing secondary pollution to the entire hydraulic energy system.

[0003] Traditional hydraulic system designs mostly use oil filtration devices for protection, but they fail to effectively block the pollution diffusion path caused by the wear and tear failures of the main pump. Therefore, there is an urgent need to develop a new type of hydraulic system that can real-time monitor the wear state of the main pump, actively isolate the contaminated oil, and establish a multiple protection mechanism to block the conduction path of pollutants inside the hydraulic energy system and ensure that the cleanliness of the hydraulic oil in the hydraulic oil tank is maintained within the safe threshold range. Summary of the Invention

[0004] To solve the problem of oil pollution diffusion caused by plunger pump failures, the present invention provides a plunger pump, a hydraulic system and a fault response control method thereof.

[0005] In a first aspect, the present invention provides a plunger pump, which includes:

[0006] A pump main body, which includes a housing, a swash plate, a rotor and a plunger; the swash plate, the rotor and the plunger are all located in the housing; the swash plate is rotatably connected to the housing; the rotor is rotatably connected to the housing, and the plunger is slidably connected to the rotor; one end of the plunger abuts against the swash plate; the housing has a first oil outlet and a return oil port;

[0007] An outlet switch valve, which is detachably connected to the housing; the outlet switch valve controls the opening and closing of the first oil outlet; the outlet switch valve is a hydraulic control valve; the outlet switch valve has a hydraulic control oil port;

[0008] A pressure feedback valve, which is detachably connected to the housing; the pressure feedback valve adjusts the tilt angle of the swash plate according to the size of the load;

[0009] A unloading valve, which is detachably connected to the pressure feedback valve; an outlet of the unloading valve communicates with the pressure feedback valve;

[0010] A signal receiving valve, which is detachably connected to the housing; the signal receiving valve controls the first oil outlet or the oil return port to communicate with the hydraulic control port and the inlet of the unloading valve; in a state where the first oil outlet communicates with the hydraulic control port, the outlet switching valve closes the first oil outlet; in a state where the oil return port communicates with the hydraulic control port, the outlet switching valve opens the first oil outlet; in a state where the first oil outlet communicates with the inlet of the unloading valve, the unloading valve opens and the swash plate tilt angle is adjusted to 0; in a state where the oil return port communicates with the inlet of the unloading valve, the unloading valve closes;

[0011] A fault detector, which is detachably connected to the housing; the fault detector detects fault data of the pump body; the fault detector is electrically connected to the signal receiving valve.

[0012] In some embodiments, the outlet switching valve includes a valve body, a valve core and an elastic driving member; the valve core is located inside the valve body; the valve core is slidably connected to the valve body; the valve body has a hydraulic control port, an oil inlet and a second oil outlet; the valve core separates the hydraulic control port from the oil inlet and the second oil outlet respectively; the elastic driving member applies a driving force to the valve core to move towards the second oil outlet; the movement of the valve core controls the on-off of the oil inlet and the second oil outlet; the oil inlet communicates with the first oil outlet of the pump body.

[0013] In some embodiments, the signal receiving valve is a two-position three-way valve; the signal receiving valve has a first oil port, a second oil port and a third oil port; the first oil port communicates with the first oil outlet; the second oil port communicates with the oil return port; the third oil port communicates with the inlet of the unloading valve and the hydraulic control port respectively; the signal receiving valve has a first working position and a second working position;

[0014] In a state of the first working position, the first oil port communicates with the third oil port and the second oil port is disconnected;

[0015] In a state of the second working position, the second oil port communicates with the third oil port and the first oil port is disconnected.

[0016] In some embodiments, the fault detector includes an oil pressure detector and an oil temperature detector.

[0017] In a second aspect, the present invention provides a hydraulic system, which includes the piston pump according to any one of the first aspect, and further includes:

[0018] A load device, and the plunger pump drives the load device to operate.

[0019] In a third aspect, the present invention provides a hydraulic system fault response control method, which is applied to the hydraulic system described in the second aspect. The hydraulic system fault response control method includes:

[0020] Step S10, based on the plunger pump being in a working state, obtaining the fault level of the pump body detected by the fault detector in real time at a preset frequency; when the plunger pump is in the working state, the oil return port of the pump body is respectively communicated with the inlet of the unloading valve and the oil control port of the outlet switching valve;

[0021] Step S20, based on the fault level of the pump body exceeding a first threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve respectively.

[0022] In some embodiments, step S20 includes: based on the fault level of the pump body exceeding the first threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve in sequence at a preset interval duration.

[0023] In some embodiments, step S20 includes:

[0024] Step S21, based on the fault level of the pump body being between the first threshold and the second threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve in sequence at an interval of a first preset duration; the second threshold is greater than the first threshold.

[0025] In some embodiments, step S20 includes:

[0026] Step S22, based on the fault level of the pump body being between the second threshold and the third threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve in sequence at an interval of a second preset duration; the third threshold is greater than the second threshold; the second preset duration is less than the first preset duration.

[0027] In some embodiments, the hydraulic system fault response control method further includes:

[0028] Step S30, based on the fault level of the pump body being between the first threshold and the base threshold, controlling at least part of the load devices to be closed; the first threshold is greater than the base threshold;

[0029] Step S40: Based on at least some of the load devices pausing operation due to a fault, accumulate the duration during which the fault level is greater than the base threshold.

[0030] Step S50: Based on the duration being greater than a preset duration, control the signal receiving valve to connect the first oil outlet to the inlet of the unloading valve and the hydraulic control oil port of the outlet switching valve respectively.

[0031] Step S60: Based on the duration being less than the preset duration, restart the load device that paused operation due to a fault.

[0032] To solve the problem of oil pollution diffusion caused by plunger pump faults, the present invention has the following advantages:

[0033] The real-time fault degree of the plunger pump is detected by a fault detector and a signal is sent to the signal receiving valve. Thus, the opening and closing of the first oil outlet are controlled by controlling the outlet switching valve, and the angle of the swash plate is controlled to return to zero by controlling the opening and closing of the unloading valve. When a fault occurs in the plunger pump, the swash plate angle is adjusted to 0 and the first oil outlet is closed, so that the plunger pump stops outputting oil, thereby preventing the plunger pump from discharging contaminated oil into the downstream pipeline of the hydraulic system, and further avoiding contamination of the load devices downstream of the hydraulic system. Description of the Drawings

[0034] Figure 1 Shows a structural schematic diagram of a plunger pump of an embodiment;

[0035] Figure 2 Shows a schematic diagram of the closed state of an outlet switching valve of an embodiment;

[0036] Figure 3 Shows a schematic diagram of the open state of an outlet switching valve of an embodiment;

[0037] Figure 4 Shows a functional structural schematic diagram of an outlet switching valve of an embodiment;

[0038] Figure 5 Shows a schematic flow diagram of a hydraulic system fault response control method of an embodiment.

[0039] Reference Signs: 10 Pump Body; 11 First Oil Outlet; 12 Oil Return Port; 20 Outlet Switching Valve; 21 Valve Body; 211 Hydraulic Control Oil Port; 212 Inlet Port; 213 Second Oil Outlet; 214 First Conical Surface; 22 Valve Core; 221 Second Conical Surface; 23 Elastic Driving Member; 30 Pressure Feedback Valve; 40 Unloading Valve; 50 Signal Receiving Valve; 51 First Oil Port; 52 Second Oil Port; 53 Third Oil Port. Detailed Embodiments

[0040] The present disclosure will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are described only to enable those of ordinary skill in the art to better understand and thus implement the present disclosure, and do not imply any limitation on the scope of the present disclosure.

[0041] As used herein, the term "comprising" and its variants are to be construed as open-ended terms meaning "including but not limited to". The term "based on" is to be construed as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be construed as "at least one embodiment". The term "another embodiment" is to be construed as "at least one other embodiment". The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation. Also, in addition to being able to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to the specific circumstances. In addition, the terms "mounted", "arranged", "provided with", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral structure; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, or there may be internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and do not indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, the meaning of "a plurality" is two or more.

[0042] As the core power component of the hydraulic system, the main hydraulic pump functions to continuously output hydraulic energy that meets the pressure and flow requirements of the system. When wear failures occur in the hydraulic pump, the pollutants generated will enter the hydraulic system along with the output oil, resulting in the contamination of accessories in the system. Existing technical solutions generally use filtering equipment to reduce the spread of contamination. However, when the pollutants accumulate at the system filter and cause abnormal pressure differences in the return oil pipeline, the return oil safety valve of the system will open abnormally, causing the contaminated oil to flow back to the fuel tank and resulting in more serious contamination. Therefore, there is an urgent need to develop a new hydraulic system that can monitor the wear status of the main pump in real time and isolate the contaminated oil in a timely manner to block the conduction path of pollutants within the hydraulic energy system.

[0043] In this embodiment, a piston pump is provided, as Figure 1 shown. The piston pump may include a pump body 10, an outlet switch valve 20, a pressure feedback valve 30, a relief valve 40, a signal receiving valve 50, and a fault detector. The pump body 10 may include a housing, a swash plate, a rotor, and a piston. The swash plate, the rotor, and the piston are all located in the housing. The swash plate is rotatably connected to the housing, the rotor is rotatably connected to the housing, the piston is slidably connected to the rotor, and one end of the piston abuts against the swash plate. The housing has a first oil outlet 11 and an oil return port 12. The first oil outlet 11 may communicate the piston pump with the hydraulic system, and the oil return port 12 may communicate the piston pump with the fuel tank.

[0044] The outlet switch valve 20 is detachably connected to the housing. The outlet switch valve 20 can control the opening and closing of the first oil outlet 11. By closing the outlet switch valve 20, it is possible to prevent the contaminated oil from continuing to enter the hydraulic system for circulation. The outlet switch valve 20 is a hydraulically controlled valve, and the outlet switch valve 20 has a hydraulic control oil port 211. By connecting the hydraulic control oil port 211 to different pipelines, the opening and closing of the outlet switch valve 20 can be controlled.

[0045] The pressure feedback valve 30 is detachably connected to the housing. The pressure feedback valve 30 can automatically adjust the tilt angle of the swash plate according to the size of the load in the hydraulic system, thereby controlling the output power of the piston pump.

[0046] The relief valve 40 is detachably connected to the pressure feedback valve 30. The outlet of the relief valve 40 communicates with the pressure feedback valve 30.

[0047] The signal receiving valve is detachably connected to the housing. The signal receiving valve can control the first oil outlet 11 or the oil return port 12 to communicate with the hydraulic control port 211 and the inlet of the unloading valve 40. In the state where the first oil outlet 11 is communicated with the hydraulic control port 211, high-pressure oil enters the hydraulic control port 211, and the outlet switching valve 20 will close the first oil outlet 11 to prevent oil from entering the hydraulic system, thereby preventing the downstream load device of the hydraulic system from being contaminated. In the state where the oil return port 12 is communicated with the hydraulic control port 211, low-pressure oil enters the hydraulic control port 211, and the outlet switching valve 20 will open the first oil outlet 11, and the oil can enter the hydraulic system to participate in the cycle normally. In the state where the first oil outlet 11 is communicated with the inlet of the unloading valve 40, the unloading valve 40 is opened, high-pressure oil enters the pressure feedback valve 30, the tilt angle of the swash plate is adjusted to 0, and the piston pump stops sucking and pressing oil, so that the contaminated oil stops entering the hydraulic system. In the state where the oil return port 12 is communicated with the inlet of the unloading valve 40, the unloading valve 40 is closed, and the pressure feedback valve 30 normally adjusts the swash plate angle according to the load.

[0048] The fault detector is detachably connected to the housing. The fault detector can detect the fault data of the pump body 10, such as whether the oil temperature and oil pressure are normal, etc. The fault detector is electrically connected to the signal receiving valve 50, and the signal receiving valve 50 adjusts the potential according to the signal output by the fault detector.

[0049] The signal receiving valve 50 controls the opening and closing of the first oil outlet 11 by controlling the outlet switching valve 20, and controls whether the angle of the swash plate returns to zero by controlling the opening and closing of the unloading valve 40. When the fault detector detects an abnormality in the piston pump, the swash plate angle is adjusted to 0, the first oil outlet 11 is closed, and the piston pump stops outputting oil, thereby preventing the contaminated oil in the piston pump from entering the downstream pipeline of the hydraulic system and avoiding contamination of the downstream load device of the hydraulic system, so as to avoid the formation of silt at the hydraulic system filter and trigger the abnormal opening of the system oil return safety valve, and further avoid the situation where the contaminated oil containing wear products flows back reversely to the hydraulic oil tank.

[0050] In this embodiment, as Figure 2 shown, the outlet switching valve 20 includes a valve body 21, a valve core 22 and an elastic driving member 23. The valve core 22 is located inside the valve body 21, and the valve core 22 is slidably connected to the valve body 21. The valve body 21 has a hydraulic control port 211, an oil inlet 212 and a second oil outlet 213. The valve core 22 separates the hydraulic control port 211 from the oil inlet 212 and the second oil outlet 213 respectively. The elastic driving member 23 can drive the valve core 22 to move towards the first oil outlet 11; the movement of the valve core 22 controls the opening and closing of the oil inlet 212 and the second oil outlet 213, and the oil inlet 212 is communicated with the first oil outlet 11 of the pump body 10. Among them, as Figure 4As shown, the valve body 21 may further include a first conical surface 214, and the valve core 22 may include a second conical surface 221. The first conical surface 214 is located at the entrance of the second oil outlet 213 near one end of the valve core 22, and the second conical surface 221 is located at one end of the valve core 22 near the second oil outlet 213. The inclination angles of the first conical surface 214 and the second conical surface 221 are different. When the first oil outlet 11 is in communication with the oil inlet 212, the first conical surface 214 and the second conical surface 221 are in contact, and the first conical surface 214 and the second conical surface 221 form an angle with the opening facing the direction of the oil inlet 212 in the cross-section passing through the axis of the valve core 22. The pressure of the high-pressure oil entering the oil inlet 212 through the first oil outlet 11 can act on the second conical surface 221, and the component force of the acting force along the axial direction of the valve core 22 can cause the valve core 22 to tend to move away from the second oil outlet 213.

[0051] When the hydraulic control oil port 211 is in communication with the oil return port 12, low-pressure oil enters the hydraulic control oil port 211, and the oil inlet 212 is in communication with the first oil outlet 11. The high-pressure oil entering the oil inlet 212 will act on the second conical surface 221 at one end of the valve core 22 near the second oil outlet 213. The thrust generated by the high-pressure oil is greater than the resultant force of the low-pressure oil thrust and the elastic driving part. Therefore, the high-pressure oil drives the valve core 22 to move away from the second oil outlet 213. At this time, the oil inlet 212 is in communication with the second oil outlet 213, and the oil can enter the hydraulic system along the first oil outlet 11, the oil inlet 212, and the second oil outlet 213, realizing the normal operation of the plunger pump. When the first oil outlet 11 is in communication with the hydraulic control oil port 211, high-pressure oil enters the hydraulic control oil port 211. At this time, the oil pressures at both ends of the valve core 22 are equal and opposite in direction. Therefore, the valve core 22 moves towards the second oil outlet 213 under the driving force of the elastic driving member 23 until the second oil outlet 213 is blocked from the oil inlet 212, that is, the closing of the first oil outlet 11 is realized. As Figure 3 shown, at this time, the valve core 22 cuts off the passage between the oil inlet 212 and the second oil outlet 213, and the contaminated oil cannot flow into the hydraulic system along the path of the first oil outlet 11, the oil inlet 212, and the second oil outlet 213.

[0052] In this embodiment, as Figure 1 shown, the signal receiving valve 50 may be a two-position three-way valve, and the signal receiving valve 50 can control the on-off of the unloading valve 40 and the outlet switch valve 20 through the change between two working positions. The signal receiving valve 50 has a first oil port 51, a second oil port 52, and a third oil port 53. The first oil port 51 is in communication with the first oil outlet 11; the second oil port 52 is in communication with the oil return port 12; the third oil port 53 is respectively in communication with the inlet of the unloading valve 40 and the hydraulic control oil port 211. The signal receiving valve 50 has a first working position and a second working position.

[0053] In the state of the first working position, the first oil port 51 is communicated with the third oil port 53, and the second oil port 52 is disconnected. Thus, both the inlet of the unloading valve 40 and the hydraulic control oil port 211 are communicated with the first oil outlet 11. The high-pressure oil enters the pressure feedback valve 30 through the unloading valve 40, the swash plate tilt angle is adjusted to 0, and the plunger pump stops sucking and discharging oil. The high-pressure oil enters the hydraulic control oil port 211. At this time, the oil pressures at both ends of the valve core 22 are equal and opposite in direction. Thus, the valve core 22 moves towards the second oil outlet 213 under the driving force of the elastic driving member 23 until the second oil outlet 213 is blocked from the oil inlet 212, and the oil fluid cannot flow into the hydraulic system along the second oil outlet 213. When a fault occurs in the plunger pump, the signal receiving valve 50 is adjusted to the first working position, so that the contaminated oil fluid can be isolated in the hydraulic pump as early as possible, avoiding the spread of contamination along the hydraulic system.

[0054] In the state of the second working position, the second oil port 52 is communicated with the third oil port 53, and the first oil port 51 is disconnected. Thus, both the inlet of the unloading valve 40 and the hydraulic control oil port 211 are communicated with the oil return port 12. The unloading valve 40 is closed, and the pressure feedback valve 30 works normally. The hydraulic control oil port 211 is communicated with the low-pressure oil. The valve core 22 moves in the direction away from the second oil outlet 213 under the action of the high-pressure oil at the oil inlet 212. The oil fluid can flow into the hydraulic system successively through the first oil outlet 11, the oil inlet 212 and the second oil outlet 213, and the hydraulic system maintains a normal working state.

[0055] In this embodiment, the fault detector may include an oil pressure detector and an oil temperature detector. After a fault occurs in the plunger pump, both the oil pressure and the oil temperature will change. The fault detector can detect the oil pressure change value and the oil temperature change value within a certain time range. If the change value exceeds a certain threshold, it can be considered that a fault has occurred in the plunger pump. The fault detector will transmit a signal to the signal receiving valve, and then control the on-off of the unloading valve 40 and the outlet switch valve 20, so that the hydraulic system stops working to avoid the spread of contamination.

[0056] In this embodiment, a hydraulic system is provided. The hydraulic system includes the plunger pump in any of the above embodiments, and further includes a load device. The plunger pump can drive the load device to work. At the same time, the swash plate in the plunger pump will adjust the tilt angle according to the load device to control the output power of the plunger pump, so that the load device can obtain the required driving force and work normally.

[0057] Before the plunger pump starts and when the engine starts, the plunger pump can be controlled to be in a state of zero pressure and zero flow output, that is, the output power is 0, so as to reduce the starting input power required by the engine. After the plunger pump starts, in this embodiment, a hydraulic system fault response control method is provided. The hydraulic system fault response control method is applied to the hydraulic system in the above embodiment, as Figure 4As shown, the fault response control method of the hydraulic system includes steps S10 to S20, and the details of each step are as follows:

[0058] Step S10: Based on the plunger pump being in the working state, the fault level of the pump body 10 detected by the fault detector is obtained in real time at a preset frequency. Among them, the fault detector can judge whether the plunger pump fails and the fault level by detecting the oil pressure and oil temperature. When the plunger pump is in the working state, the oil return port 12 of the pump body 10 is respectively communicated with the inlet of the unloading valve 40 and the oil control port of the outlet switch valve 20. The unloading valve 40 is closed, and the pressure feedback valve 30 works normally. The hydraulic oil control port 211 is communicated with the low-pressure oil. The spool 22 moves in the direction away from the second oil outlet 213 under the action of the high-pressure oil at the oil inlet 212. The oil can flow through the first oil outlet 11, the oil inlet 212 and the second oil outlet 213 in sequence and flow into the hydraulic system, and the hydraulic system maintains a normal working state.

[0059] Step S20: Based on the fault level of the pump body 10 exceeding the first threshold, the control signal receiving valve 50 communicates the first oil outlet 11 of the pump body 10 with the inlet of the unloading valve 40 and the hydraulic oil control port 211 of the outlet switch valve 20 respectively. The high-pressure oil enters the pressure feedback valve 30 through the unloading valve 40, the swash plate tilt angle is adjusted to 0, and the plunger pump stops sucking and pressing oil. The high-pressure oil enters the hydraulic oil control port 211. At this time, the oil pressures at both ends of the spool 22 are equal and opposite in direction. Thus, the spool 22 moves in the direction of the second oil outlet 213 under the driving force of the elastic driving member 23 until the second oil outlet 213 is blocked from the oil inlet 212, and the oil cannot flow into the hydraulic system along the second oil outlet 213, thereby avoiding the spread of pollution along the hydraulic system.

[0060] In this embodiment, step S20 may include: Based on the fault level of the pump body 10 exceeding the first threshold, the control signal receiving valve 50 communicates the first oil outlet 11 of the pump body 10 with the inlet of the unloading valve 40 and the hydraulic oil control port 211 of the outlet switch valve 20 in sequence at a preset interval, so that the high-pressure oil first enters the pressure feedback valve 30, the swash plate angle is adjusted to 0, the outlet pressure of the plunger pump is adjusted to low pressure, and then the outlet switch valve 20 is closed, so that the spool 22 cuts off the passage between the oil inlet 212 and the second oil outlet 213, and the oil outlet of the plunger pump is closed. Adjusting the swash plate angle first and then closing the plunger pump outlet can prevent the plunger pump from being damaged due to excessive pressure inside the plunger pump.

[0061] In this embodiment, step S20 may include step S21, and the details are as follows:

[0062] Step S21: Based on the fault level of the pump body 10 being between the first threshold and the second threshold, the control signal receiving valve 50 connects the first oil outlet 11 of the pump body 10 to the inlet of the unloading valve 40 and the hydraulic control oil port 211 of the outlet switch valve 20 at intervals of the first preset duration in sequence. Herein, the second threshold is greater than the first threshold. When the fault level of the pump body 10 is relatively low, the interval time between adjusting the swash plate angle to 0 and closing the outlet of the pump body 10 can be controlled to be relatively long, avoiding excessive pressure inside the pump body 10 caused by the plunger in the pump body 10 still operating when the outlet of the pump body 10 is closed.

[0063] In this embodiment, step S20 further includes step S22, which is described in detail as follows:

[0064] Step S22: Based on the fault level of the pump body 10 being between the second threshold and the third threshold, the control signal receiving valve 50 connects the first oil outlet 11 of the pump body 10 to the inlet of the unloading valve 40 and the hydraulic control oil port 211 of the outlet switch valve 20 at intervals of the second preset duration in sequence. Herein, the third threshold is greater than the second threshold, and the second preset duration is less than the first preset duration. That is, when the fault level of the pump body 10 is relatively large, the interval time between adjusting the swash plate angle to 0 and closing the outlet of the pump body 10 can be controlled to be relatively short. On the one hand, it can quickly stop the oil suction and oil discharge actions of the plunger pump, and on the other hand, it can also prevent the contaminated oil from polluting the downstream load devices along the hydraulic system circuit.

[0065] In other embodiments, when the fault level of the pump body 10 is too large, the connection between the input shaft and the main shaft of the plunger pump can also be controlled to be disconnected, so that the plunger pump stops working, avoiding the blockage of the self - oil return filter of the plunger pump. The self - oil return filter of the plunger pump and the oil return filter of the hydraulic system are two different filters.

[0066] In this embodiment, the fault response control method of the hydraulic system further includes steps S30 to S60, which are described in detail as follows:

[0067] Step S30: Based on the fault level of the pump body 10 being between the first threshold and the base threshold, at least some of the load devices are controlled to be closed. Herein, the first threshold is greater than the base threshold.

[0068] In the state where the fault level is less than the base threshold, the pump body 10 is in a normal working state. When the fault level is between the first threshold and the base threshold, it may not be a wear fault of the pump body 10, but a fault in the hydraulic system that can be automatically reset and eliminated. For example, when the set oil pressure of the overflow valve is improper and the oil pressure is high and the temperature rises, the hydraulic system can automatically control and adjust the set oil pressure of the overflow valve to quickly stabilize the oil temperature.

[0069] Therefore, for minor faults that can be quickly reset, the swash plate angle does not need to be zeroed, nor does the outlet of the pump body 10 need to be closed. Instead, some of the load devices are closed. Based on the principle of constant pressure variable regulation, the swash plate angle also automatically changes with the decrease in load, reducing the output power of the plunger pump.

[0070] Step S40: Based on at least one load device pausing operation due to a fault, accumulate the duration during which the cumulative fault level is greater than the basic threshold.

[0071] Step S50: Based on the duration being greater than the preset duration, the control signal receiving valve 50 connects the first oil outlet 11 to the inlet of the unloading valve 40 and the hydraulic control port 211 of the outlet switch valve 20 respectively, zeroing the swash plate inclination angle, closing the first oil outlet 11, and performing manual maintenance. Here, the preset duration can be three minutes.

[0072] Step S60: Based on the duration being less than the preset duration, restart the load device that paused operation due to a fault.

[0073] Among them, closing some of the load devices can play a buffering role. On the one hand, it prepares for the actions of zeroing the swash plate inclination angle and closing the first oil outlet 11 caused by wear faults, and at the same time ensures the continuous operation of the hydraulic system, avoiding frequent unexpected shutdowns.

[0074] Those of ordinary skill in the art can understand that the above embodiments are specific cases for implementing the present disclosure. In actual applications, various changes can be made to them in form and details without departing from the scope of the present disclosure.

Claims

1. A plunger pump, characterized in that, The plunger pump includes: A pump body, which includes a housing, a swash plate, a rotor, and a plunger; the swash plate, the rotor, and the plunger are all located in the housing; the swash plate is rotatably connected to the housing; the rotor is rotatably connected to the housing, and the plunger is slidably connected to the rotor; one end of the plunger abuts against the swash plate; the housing has a first oil outlet and an oil return port; An outlet switch valve, which is detachably connected to the housing; the outlet switch valve controls the opening and closing of the first oil outlet; the outlet switch valve is a hydraulic control valve; the outlet switch valve has a hydraulic control oil port; A pressure feedback valve, which is detachably connected to the housing; the pressure feedback valve adjusts the tilt angle of the swash plate according to the load; A unloading valve, which is detachably connected to the pressure feedback valve; the outlet of the unloading valve is communicated with the pressure feedback valve; A signal receiving valve, which is detachably connected to the housing; the signal receiving valve controls the first oil outlet or the oil return port to be communicated with the hydraulic control oil port and the inlet of the unloading valve; in the state where the first oil outlet is communicated with the hydraulic control oil port, the outlet switch valve closes the first oil outlet; in the state where the oil return port is communicated with the hydraulic control oil port, the outlet switch valve opens the first oil outlet; in the state where the first oil outlet is communicated with the inlet of the unloading valve, the unloading valve opens, and the tilt angle of the swash plate is adjusted to 0; in the state where the oil return port is communicated with the inlet of the unloading valve, the unloading valve closes; A fault detector, which is detachably connected to the housing; the fault detector detects the fault data of the pump body; the fault detector is electrically connected to the signal receiving valve; The outlet switch valve includes a valve body, a valve core, and an elastic driving member; the valve core is located in the valve body; the valve core is slidably connected to the valve body; the valve body has a hydraulic control oil port, an oil inlet, and a second oil outlet; the valve core separates the hydraulic control oil port from the oil inlet and the second oil outlet respectively; the elastic driving member applies a driving force to the valve core to move towards the second oil outlet; the movement of the valve core controls the on-off of the oil inlet and the second oil outlet; the oil inlet is communicated with the first oil outlet of the pump body; The signal receiving valve is a two-position three-way valve; the signal receiving valve has a first oil port, a second oil port, and a third oil port; the first oil port is communicated with the first oil outlet; the second oil port is communicated with the oil return port; the third oil port is respectively communicated with the inlet of the unloading valve and the hydraulic control oil port; the signal receiving valve has a first working position and a second working position; In the state of the first working position, the first oil port is communicated with the third oil port, and the second oil port is disconnected; In the state of the second working position, the second oil port is communicated with the third oil port, and the first oil port is disconnected.

2. The plunger pump according to claim 1, wherein The fault detector includes an oil pressure detector and an oil temperature detector.

3. A hydraulic system, wherein The hydraulic system includes: A plunger pump as described in any one of claims 1-2; A load device, and the plunger pump drives the load device to operate.

4. A fault response control method for a hydraulic system, applied to the hydraulic system described in claim 3; characterized in that, The fault response control method for the hydraulic system includes: Step S10, based on the plunger pump being in the working state, obtaining the fault level of the pump body detected by the fault detector in real time at a preset frequency; when the plunger pump is in the working state, the oil return port of the pump body is respectively communicated with the inlet of the unloading valve and the oil control port of the outlet switching valve; Step S20, based on the fault level of the pump body exceeding a first threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve respectively.

5. According to the fault response control method for a hydraulic system described in claim 4, characterized in that, Step S20 includes: based on the fault level of the pump body exceeding a first threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve in sequence at a preset interval duration.

6. According to the fault response control method for a hydraulic system described in claim 5, characterized in that, Step S20 includes: Step S21, based on the fault level of the pump body being between the first threshold and the second threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve in sequence at an interval of a first preset duration; the second threshold is greater than the first threshold.

7. According to the fault response control method for a hydraulic system described in claim 6, characterized in that, Step S20 includes: Step S22, based on the fault level of the pump body being between the second threshold and the third threshold, controlling the signal receiving valve to communicate the first oil outlet of the pump body with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve in sequence at an interval of a second preset duration; the third threshold is greater than the second threshold; the second preset duration is less than the first preset duration.

8. According to the fault response control method for a hydraulic system described in claim 4, characterized in that, The fault response control method for the hydraulic system further includes: Step S30, based on the fault level of the pump body being between the first threshold and the base threshold, controlling at least part of the load devices to be closed; the first threshold is greater than the base threshold; Step S40, based on at least part of the load devices pausing operation due to a fault, accumulating the duration during which the fault level is greater than the base threshold; Step S50, based on the duration being greater than a preset duration, controlling the signal receiving valve to communicate the first oil outlet with the inlet of the unloading valve and the hydraulic oil control port of the outlet switching valve respectively; Step S60, based on the duration being less than the preset duration, restarting the load devices that paused operation due to a fault.

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