Leak Detection Method for Pumping Unit and Leak Detection System for Pumping Unit

Abstract

The present invention relates to the leakage detection technology of a pressure pipeline system. Specifically, it relates to a method for detecting leakage of a pumping unit, which includes the following steps: First, fill the hopper with fluid, and start pumping by the pumping unit to be tested, so that fluid pressure is formed in the hopper; Second, obtain the current fluid pressure and adjust and establish the target oil supply pressure according to the current fluid pressure; Third, close the discharge port of the hopper, drive the drive cylinder of the pumping unit to be tested with the target oil supply pressure, and maintain a preset pressurization duration; Fourth, record the displacement advanced by the drive cylinder within the preset pressurization duration; Fifth, perform leakage analysis on the pumping unit to be tested according to the displacement, and determine whether there is leakage. The present invention can automatically debug parameters to adapt to the debugging requirements of pumping units of different product models, and has accurate detection results and high operation efficiency.

Description

Technical Field

[0001] The present invention relates to the leakage detection technology of a pressure pipeline system, and specifically, to a method for detecting leakage of a pumping unit. In addition, the present invention also relates to a system for detecting leakage of a pumping unit. Background Art

[0002] A concrete pump truck is an important construction machinery for building various types of engineering buildings. Among them, the pumping unit is the core power mechanism of the pump truck. Its function is to convert the pressure energy provided by the hydraulic system into the reciprocating motion of the concrete piston in the concrete cylinder, so that the concrete piston pushes the concrete through the distribution valve, the concrete cylinder, and the delivery pipe to reach the construction destination. In order to prevent the pumping resistance from increasing during the concrete pumping process and ensure the pumpability of the concrete, it is necessary to maintain the water content in the concrete mix as much as possible. Therefore, the sealing performance of the pumping unit and the pipeline is extremely important for maintaining the water content during the concrete pumping process.

[0003] When the pumping unit is working, the wear plate and the cutting ring are in planar contact. Due to processing and installation errors, leakage at the contact surface is inevitable, and the clearance values in all directions are uncertain. During the debugging process, it is necessary to quantitatively measure the leakage amount or leakage speed of water under specific working conditions. Currently, the industry conducts leakage detection of the pumping unit during the whole vehicle debugging.

[0004] Specifically, referring to Figure 1 , a plugging module is provided at the discharge pipe of the pumping unit. The plugging module includes a plug, an exhaust pipe, and a valve. A displacement detection module is provided on the pumping cylinder. The main method for detecting leakage is to block the outlet of the discharge pipe to form a sealed cavity, fill the sealed cavity with a test liquid, use the pumping drive assembly to pump the test liquid in the hopper into the discharge pipe until the test liquid continuously overflows from the exhaust pipe, and block the outlet of the discharge pipe; pressurize the sealed cavity through the pumping drive assembly and maintain a preset pressurization duration, obtain the extension amount of the piston rod within the preset pressurization duration, and conduct leakage analysis on the extension amount. The above leakage detection device and method indirectly obtain the leakage situation of the test liquid through the extension amount of the piston rod, thereby reducing the measurement difficulty. However, during the actual measurement process, the pressure of the test liquid is not only related to the set value of the overflow pressure of the whole vehicle hydraulic system but also related to the model of the pumping unit. Adjusting to a specific load pressure requires continuous adjustment and manual conversion, with low efficiency. And when multiple load pressure tests are required, it is necessary to manually frequently adjust the hydraulic system pressure to match.

[0005] In view of the above problems, it is necessary to design a new method and system for detecting leakage of a pumping unit to alleviate or overcome the above defects of the prior art. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide a leak detection method for a pumping unit, which can realize the automatic debugging of the oil supply pressure of the hydraulic drive unit and the automatic calculation and analysis of the leak detection amount of the pumping unit to be tested through a control unit.

[0007] In addition, the technical problem to be solved by the present invention is to provide a leak detection system for a pumping unit, which can not only automatically debug parameters to adapt to the debugging requirements of different product models during use, but also has accurate detection results and high operation efficiency.

[0008] To solve the above technical problems, the present invention provides a leak detection method for a pumping unit, including the following steps:

[0009] First, fill the hopper with fluid, and start pumping the pumping unit to be tested, so that a fluid pressure is formed in the hopper;

[0010] Second, obtain the current fluid pressure, and adjust and establish a target oil supply pressure according to the current fluid pressure;

[0011] Third, close the discharge port of the hopper, drive the drive cylinder of the pumping unit to be tested with the target oil supply pressure, and maintain a preset pressurization duration;

[0012] Fourth, record the displacement advanced by the drive cylinder within the preset pressurization duration;

[0013] Fifth, perform leakage analysis on the pumping unit to be tested according to the displacement, and determine whether there is leakage.

[0014] Preferably, the second step includes that when the current fluid pressure is within the standard test pressure range, obtain the current oil supply pressure, and set the current oil supply pressure as the target oil supply pressure; when the current fluid pressure is not within the standard test pressure range, adjust the oil supply pressure to make the current fluid pressure within the standard test pressure range, obtain the current oil supply pressure, and set the current oil supply pressure as the target oil supply pressure.

[0015] Preferably, the target oil supply pressure is adjusted and established through an oil supply pressure regulating device, and the third step includes:

[0016] a. Set the overflow opening pressure of the oil supply pressure regulating device as the target oil supply pressure through the control unit, and make the oil supply pressure regulating device open the overflow through the operation of the hydraulic pump;

[0017] b. When the oil supply pressure regulating device is in the state of opening the overflow, the current oil supply pressure is monitored in real time by the first pressure detection device 104. The difference between the monitored current oil supply pressure and the target oil supply pressure is compared, and the oil supply pressure regulating device is adjusted by the control unit until the monitored current oil supply pressure is equal to the target oil supply pressure.

[0018] Preferably, the fourth step includes reading, by the control unit, a displacement detection device installed on the drive cylinder, and detecting in real time the displacement of the cylinder piston rod by the displacement detection device.

[0019] Preferably, the fifth step includes calculating the leakage amount according to the characteristic parameters of the drive cylinder and the concrete cylinder of the pumping unit to be tested. The leakage amount is Q = 0.25πD 2 L0, and making a qualified judgment by comparing with the maximum allowable leakage value, where D is the inner diameter of the concrete cylinder and L0 is the displacement.

[0020] In addition, the present invention also provides a leakage detection system for a pumping unit, including a hydraulic drive unit for connecting with the pumping unit to be tested and a fluid loading unit for adding fluid to the pumping unit to be tested. Among them, the hydraulic drive unit includes a hydraulic pump, an inserted valve, a safety valve, and an oil supply pressure regulating device connected to the oil supply circuit. The first working oil port of the inserted valve is connected to the oil supply circuit, the second working oil port is connected to the oil return circuit, and the control oil port is connected to the oil supply control circuit. The oil supply pressure regulating device is provided on the oil supply control circuit. The connection point of the control oil port of the inserted valve on the oil supply control circuit is before the oil inlet of the oil supply pressure regulating device, and one end of the oil supply control circuit is connected to the oil supply circuit and the other end is connected to the oil return circuit. One end of the safety valve is connected to the oil supply control circuit and the other end is connected to the oil return circuit. The oil supply pressure regulating device is electrically connected to the control unit to adjust the oil supply pressure of the hydraulic drive unit by adjusting the oil supply pressure regulating device through the control unit. A first pressure detection device is provided on the oil supply circuit, and the first pressure detection device is electrically connected to the control unit.

[0021] Preferably, the fluid loading unit includes a loading circulation pipeline, which has an inlet and an outlet for connecting with the hopper liquid circuit of the pumping unit to be tested. A second pressure detection device, an electronically controlled throttle valve, and an electronically controlled switch valve are provided on the loading circulation pipeline. The second pressure detection device, the electronically controlled switch valve, and the electronically controlled throttle valve are respectively electrically connected to the control unit.

[0022] Preferably, the first pressure detection device is provided after the connection point of the oil supply control circuit and the oil supply circuit.

[0023] Specifically, the oil supply pressure regulating device is an electro-hydraulic proportional relief valve, and the overflow pressure regulation of the oil supply oil circuit is realized through this electro-hydraulic proportional relief valve. The electro-hydraulic proportional relief valve changes the overflow opening pressure through the control of the control unit to regulate the oil supply pressure of the hydraulic drive unit.

[0024] Preferably, the oil supply oil circuit has an oil supply port for supplying oil to the pumping unit to be tested, the return oil circuit is connected to the main return oil circuit, and the main return oil circuit has a return oil port for receiving the return oil of the pumping unit to be tested.

[0025] Preferably, the fluid loading unit is a water loading unit.

[0026] Preferably, the second pressure detection device is arranged at the front end of the electronically controlled on-off valve, and the electronically controlled on-off valve is arranged at the front end of the electronically controlled throttle valve.

[0027] More preferably, the electronically controlled on-off valve is an electronically controlled ball valve.

[0028] Through the above technical solutions, the leak detection system for the pumping unit of the present invention mainly has the following beneficial effects:

[0029] (1) In the hydraulic drive unit of the present invention, an oil supply pressure regulating device and a first pressure detection device are provided, and both the oil supply pressure regulating device and the first pressure detection device are electrically connected to the control unit. Through the control unit, the oil supply pressure can be monitored in real time, and by comparing the current oil supply pressure with the preset target oil supply pressure, the oil supply pressure regulating device can be automatically adjusted so that the current oil supply pressure is equal to the preset target oil supply pressure.

[0030] (2) In the fluid loading unit of the present invention, water pressure is used as the monitoring and control target, which is more in line with the simulation of specific load conditions. And compared with the method of using the oil pressure of the hydraulic system drive as the detection condition, the detection errors caused by factors such as differences in the vehicle's hydraulic system, return oil pressure, and friction resistance of the concrete piston are eliminated, and the detection results are more accurate, realizing quantitative measurement.

[0031] In addition, the leak detection method for the pumping unit of the present invention mainly has the following beneficial effects:

[0032] (1) By establishing a standard detection load in the present invention, the detection results are more accurate. And based on the debugging requirements of different product models, different standard detection loads and target oil supply pressures can be established, and the debugging parameters of different product models can be automatically matched through the control unit.

[0033] (2) According to the characteristic parameters and technical requirements of the pumping cylinders and concrete cylinders of different products, the present invention can preset detection parameters, detection calculation formulas, and quality determination conditions, and the control unit directly obtains the test conclusion, which improves the operation efficiency and also meets the requirements of flexible production.

[0034] Other features and advantages of the present invention will be described in detail in the following specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the following specific implementation, they are used to explain the present invention. However, the scope of protection of the present invention is not limited to the following drawings and specific implementation. In the drawings:

[0036] Figure 1 is a schematic structural diagram of a pumping unit measuring device disclosed in the prior art;

[0037] Figure 2 is a step block diagram of the leak detection method for the pumping unit in the specific implementation of the present invention;

[0038] Figure 3 is a schematic structural diagram of the leak detection system for the pumping unit in the specific implementation of the present invention;

[0039] Figure 4 is a hydraulic schematic diagram of the hydraulic drive unit in the specific implementation of the present invention;

[0040] Figure 5 is a hydraulic schematic diagram of the fluid loading unit in the specific implementation of the present invention;

[0041] Figure 6 is a schematic connection structure diagram of the hydraulic drive unit and the fluid loading unit with the pumping unit in the specific implementation of the present invention;

[0042] Figure 7 is a schematic structural diagram of the pumping unit in the specific implementation of the present invention.

[0043] Description of the reference numerals in the drawings of the present invention:

[0044] 1 Hydraulic drive unit 101 Oil tank

[0045] 102 Oil filter device 103 Hydraulic pump

[0046] 104 First pressure detection device 105 Oil supply pressure regulating device

[0047] 106 Safety valve 107 Cartridge valve

[0048] 108 Power device 2 Fluid loading unit

[0049] 201 Electric control switch valve 202 Second pressure detection device

[0050] 203 Electric control throttle valve 204 Loading circulation pipeline

[0051] 3. Displacement detection device of the pumping unit to be tested 301

[0052] 302 drive cylinder 303 cylinder piston rod

[0053] 304 concrete cylinder 305 concrete piston

[0054] 306 hopper 307 glasses plate

[0055] 308 cutting ring 309S pipe

[0056] L1 oil supply circuit L2 oil return circuit

[0057] L3 Oil supply control circuit L4 Main oil return circuit

[0058] AFirst working oil portBSecond working oil port

[0059] X control oil port P1 oil supply port

[0060] T1 oil return port P2 liquid inlet

[0061] T2 liquid outlet DETAILED DESCRIPTION

[0062] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and the protection scope of the present invention is not limited to the following specific embodiments.

[0063] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the description of the present invention, some directional terms are involved in order to clearly explain the technical solution of the present invention, for example, "front" refers to the starting direction of the liquid flow, and "rear" refers to the ending direction of the liquid flow. The directional terms are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0065] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features.

[0066] It is pre-stated that the hydraulic components used in the hydraulic drive unit of the present invention basically belong to the common hydraulic components in the hydraulic field. For those skilled in the hydraulic field, most hydraulic technology innovations lie in the hydraulic layout structure or hydraulic connection relationship of hydraulic devices or equipment, rather than specific individual hydraulic components. Therefore, the originality of the present invention should not be denied because a single hydraulic component itself is well-known. At the same time, since the names of the same hydraulic component vary among those skilled in the hydraulic field, in the following description, relative standard technical terms will be used for relevant technical terms and the names of hydraulic components, and other relatively common names of hydraulic components will be marked as much as possible, and their hydraulic principles will be briefly described appropriately to facilitate the understanding of the technical solution of the present invention. In addition, in the following description, the "pumping unit" refers to an assembled unit composed of a pumping oil cylinder, a concrete cylinder, a water tank, a hopper, a tie rod, etc. for pumping concrete, and "commissioning load" refers to the process of simulating a specific load during the production of the pumping unit for commissioning.

[0067] The following first refers to Figure 2 the method flow chart to describe the specific implementation of the leak detection method for the pumping unit of the present invention. On this basis, the specific implementation of the leak detection system for the pumping unit of the present invention will be described in combination with Figures 4 to 6 the hydraulic principle diagram. Finally, on the basis of the above technical solutions, the specific implementation of the measurement method for the pumping unit of the present invention will be further described in combination with Figure 7 the structure diagram of the pumping unit to be tested.

[0068] See Figure 2 , the leak detection method for the pumping unit of the present invention includes the following steps:

[0069] First, fill the hopper 306 with fluid, and start pumping of the pumping unit 3 to be tested, so that a fluid pressure is formed in the hopper 306. Specifically, add fluid into the hopper 306. When the pumping unit 3 to be tested starts pumping, the pumped fluid flows out through the valve port of the hopper 306. At this time, a fluid pressure is formed in the fluid in the hopper 306.

[0070] Second, obtain the current fluid pressure, and adjust and establish a target oil supply pressure according to the current fluid pressure.

[0071] Third, close the discharge port of the hopper 306, drive the drive cylinder 302 of the pumping unit 3 to be tested with the target oil supply pressure, and maintain a preset pressurization duration.

[0072] Fourth, record the displacement advanced by the drive oil cylinder 302 within the preset pressurization duration.

[0073] Fifth, perform a leakage analysis on the to-be-tested pumping unit 3 based on the displacement and determine whether there is leakage.

[0074] In the above technical solution, specifically in step two, a fluid pressure sensor can be arranged in the hopper 306 to detect the fluid pressure in the hopper 306. The fluid pressure sensor is electrically connected to the control unit. Then, the control unit can receive the fluid pressure fed back by the fluid pressure sensor and determine the adjustment of the oil supply pressure according to its feedback information. This adjustment step includes that when the current fluid pressure is within the standard test pressure range, obtaining the current oil supply pressure and setting the current oil supply pressure as the target oil supply pressure; when the current fluid pressure is not within the standard test pressure range, adjusting the oil supply pressure to make the current fluid pressure within the standard test pressure range, obtaining the current oil supply pressure, and setting the current oil supply pressure as the target oil supply pressure. The oil supply pressure here refers to the oil pressure for driving the to-be-tested pumping unit 3 to pump. An oil pressure sensor can be arranged at the oil supply pipeline to detect the oil supply pressure. The oil pressure sensor is electrically connected to the control unit. Then, the control unit can receive the oil supply pressure fed back by the oil pressure sensor and perform further debugging or confirmation according to its feedback information.

[0075] In the specific implementation manner of step three of the present invention, after debugging, a leakage detection is performed on the to-be-tested pumping unit 3. However, in the actual detection process, there are processing errors in the to-be-tested pumping units 3 of the same model, and the complexity of the oil circuit may cause relevant errors. Therefore, the final oil supply pressure may be different from the target oil supply pressure determined during debugging. Therefore, during the leakage detection process, further adjustment may be required. Specifically, the target oil supply pressure is established by adjusting through an oil supply pressure adjustment device. This adjustment step includes: a. Setting the overflow opening pressure of the oil supply pressure adjustment device 105 as the target oil supply pressure through the control unit, and making the oil supply pressure adjustment device 105 open the overflow by the operation of the hydraulic pump 103; b. In the state where the oil supply pressure adjustment device 105 opens the overflow, the current oil supply pressure is monitored in real time through the first pressure detection device 104. Comparing the difference between the monitored current oil supply pressure and the target oil supply pressure, and adjusting the oil supply pressure adjustment device 105 through the control unit until the monitored current oil supply pressure is equal to the target oil supply pressure. Preferably, the above oil supply pressure adjustment device 105 is an electro-hydraulic proportional relief valve, which is electrically connected to the control unit. Thus, the electro-hydraulic proportional relief valve can be directly adjusted through the control unit to adjust the oil supply pressure.

[0076] In the fourth step above, specifically, the control unit reads the displacement detection device 301 installed on the driving oil cylinder 302, and the displacement detection device 301 is used to detect the displacement of the piston rod 303 of the oil cylinder of the to-be-tested pumping unit 3 in real time.

[0077] In the fifth step of this embodiment, specifically, the leakage amount is calculated according to the characteristic parameters of the driving oil cylinder 302 and the concrete cylinder 304 of the to-be-tested pumping unit 3. The leakage amount is Q = 0.25πD 2 L0, and a qualification judgment is made by comparing with the maximum allowable leakage value. Wherein, D is the inner diameter of the concrete cylinder, and L0 is the displacement advanced by the driving oil cylinder 302 within the preset pressurization duration. The judgment condition for whether the leakage amount of the to-be-tested pumping unit 3 is qualified is that when the measured leakage amount is less than or equal to the maximum allowable leakage value, the leakage amount of the pumping unit is qualified; otherwise, it is unqualified. The calculation of the above leakage amount and the judgment of whether the leakage amount of the pumping unit is qualified are both automatically completed by the control unit. The leakage detection of the pumping unit under different load water pressures can also be carried out, and the control unit automatically generates a relationship curve between the load water pressure and the leakage amount, which can help users understand the leakage situation of the pumping unit under different load pressures in advance, so as to prevent equipment failures or safety accidents caused by excessive leakage amounts of the pumping unit.

[0078] See Figures 3 to 4 , the leakage detection system of the pumping unit of the present invention includes a hydraulic driving unit 1 for connecting with the to-be-tested pumping unit 3 and a fluid loading unit 2 for adding fluid to the to-be-tested pumping unit 3. Wherein, the hydraulic driving unit 1 includes a hydraulic pump 103, a cartridge valve 107, a safety valve 106 and an oil supply pressure regulating device 105 connected to the oil supply circuit L1. The first working oil port A of the cartridge valve 107 is connected to the oil supply circuit L1, the second working oil port B is connected to the oil return circuit L2, and the control oil port X is connected to the oil supply control circuit L3. The oil supply pressure regulating device 105 is provided on the oil supply control circuit L3. The connection point of the control oil port X of the cartridge valve 107 on the oil supply circuit L1 is located before the oil inlet C of the oil supply pressure regulating device 105. One end of the oil supply control circuit L3 is connected to the oil supply circuit L1, and the other end is connected to the oil return circuit L2. One end of the safety valve 106 is connected to the oil supply control circuit L3, and the other end is connected to the oil return circuit L2. And the oil supply pressure regulating device 105 is electrically connected to the control unit to adjust the oil supply pressure of the hydraulic driving unit 1 by adjusting the oil supply pressure regulating device 105 through the control unit. A first pressure detection device 104 is provided on the oil supply circuit L1, and the first pressure detection device 104 is electrically connected to the control unit.

[0079] In the above technical solution, the cartridge valve 107 is preferably a two-way cartridge valve. Its first working oil port A is connected to the oil supply circuit L1, so the oil pressure at the first working oil port A is equal to the oil supply pressure of the hydraulic pump 103. Its second working oil port B is connected to the oil return circuit L2, so the oil pressure at the second working oil port B is zero. Its control oil port X is connected to the oil supply control circuit L3, and the connection point of the control oil port X on the oil supply control circuit L3 is located before the oil inlet C of the oil supply pressure regulating device 105, so the oil pressure at the control oil port X is equal to the inlet oil pressure on the oil supply control circuit L3. The safety valve 106 is preferably a relief valve, and its pressure setting value is the highest safety pressure of the oil supply control circuit L3, thus avoiding situations such as oil pipe breakage or oil leakage caused by excessive pressure. The oil supply pressure regulating device 105 is preferably an electro-hydraulic proportional relief valve, and its pressure setting value is the inlet oil pressure on the oil supply control circuit L3. As known from the above description, the oil pressure at the control oil port X of the cartridge valve 107 is equal to the pressure setting value of the oil supply pressure regulating device 105. When the inlet oil pressure on the oil supply control circuit L3 has not reached the pressure setting value of the oil supply pressure regulating device 105, the oil supply pressure of the hydraulic pump 103 is equal to the inlet oil pressure on the oil supply control circuit L3. Based on the working principle of the cartridge valve 107, the oil pressure at the control oil port X is equal to the oil pressure at the first working oil port A and greater than the oil pressure at the second working oil port B, so the valve port of the cartridge valve 107 is closed. At this time, the hydraulic pump 103 continuously pumps oil until the inlet oil pressure on the oil supply control circuit L3 rises to the opening pressure of the oil supply pressure regulating device 105 and overflows back to the oil tank 101. At this time, the oil pressure at the control oil port X decreases, so the oil pressure at the first working oil port A is greater than the oil pressure at the control oil port X, and the valve port of the cartridge valve 107 opens. The oil on the oil supply circuit L1 flows in from the first working oil port A of the cartridge valve 107 and flows out from the second working oil port B of the cartridge valve 107 to the oil tank 101, thereby being able to assist the oil supply pressure regulating device 105 to complete the rapid unloading of the oil circuit, so that the oil supply pressure of the hydraulic drive unit 1 is basically equal to the pressure setting value of the oil supply pressure regulating device 105. A first pressure detection device 104 is also provided on the oil supply circuit L1, and both the first pressure detection device 104 and the oil supply pressure regulating device 105 are electrically connected to the control unit. Then, the oil supply pressure on the oil supply circuit L1 can be monitored in real time through the control unit, the oil supply pressure is compared with the preset target oil supply pressure value, and the difference between the two is calculated. Based on this, the pressure setting value of the oil supply pressure regulating device 105 is adjusted through the control unit, so as to adjust the oil supply pressure on the oil supply circuit L1 to be basically equal to the preset target oil supply pressure, so that the hydraulic drive unit 1 supplies oil to the outside at a constant oil pressure. In the above technical solution, the fluid loading unit 2 is mainly used to inject fluid into the hopper 306 of the to-be-tested pumping unit 3, so as to form a fluid pressure inside it, and in this embodiment, the fluid is preferably water.

[0080] In Figure 4In the specific embodiment shown, the above hydraulic pump 103 is driven to rotate by the power device 108 to pump oil. The power device 108 can be an engine or a motor, or can be other forms of power devices 108. It should be noted that in the hydraulic drive unit 1, the power device 108 for driving the hydraulic pump 103 operates in a stable working state so that its rotational speed remains constant or substantially constant, which is well-known to those skilled in the art. In the technical solution of the present invention, unless otherwise specified, the working state of the power device 108 is in a stable working state. The control unit can adopt an integrated control unit mainly composed of an electronic control unit, a single-chip microcomputer, and a PLC, and can integrate corresponding signal amplifiers, signal conversion units, etc. according to application needs, or can adopt an electronic control unit commonly used in construction machinery.

[0081] In this embodiment, an oil filtering device 102 is provided between the oil inlet of the hydraulic pump 103 and the fuel tank 101. The oil filtering device 102 includes an oil suction filter, a bypass valve, and a signal transmitter. The oil filtering device 102 can remove larger solid impurities in the oil, thereby effectively ensuring the normal operation and rotation of the hydraulic pump.

[0082] The above first pressure detection device 104 is provided after the connection point of the oil supply control oil path L3 and the oil supply oil path L1. The first pressure detection device 104 is a pressure sensor, which can convert the detected pressure signal into an electrical signal and transmit it to the control unit so that the control unit can complete the control accuracy requirement of the target pressure according to the pressure information fed back by the pressure sensor. In addition, the first pressure detection device 104 can also adopt other forms. Below Figure 5 The second pressure detection device 202 adopted by the fluid loading unit 2 in the specific embodiment shown can be the same, and will not be elaborated here.

[0083] In Figure 4In the illustrated embodiment, the oil supply pressure regulating device 105 is an electro-hydraulic proportional relief valve, which is an electro-hydraulic control component commonly used in the hydraulic field. It can mainly adjust the continuous overflow opening pressure by controlling the proportional electromagnet. For example, it can be an electromagnetic proportional relief valve, an electro-hydraulic proportional relief valve, etc. The level of the inlet pressure of the electro-hydraulic proportional relief valve is directly proportional to the magnitude of the input signal current, that is, the inlet oil pressure is controlled by the magnitude of the current of the input electromagnet. And since the electro-hydraulic proportional relief valve is electrically connected to the control unit, different magnitudes of signal currents can be input to the electro-hydraulic proportional relief valve through the control unit to control the magnitude of the overflow opening pressure of the electro-hydraulic proportional relief valve, so as to achieve the overflow pressure regulation of the oil supply line L1, that is, the magnitude of the oil supply pressure of the hydraulic drive unit 1 can be controlled. Regarding the internal structure and control principle of the electro-hydraulic proportional relief valve, reference can be made to relevant hydraulic manuals, which will not be elaborated here. Additionally, in a hydraulic oil supply system, the overflow pressure regulation function of the relief valve is widely used. That is, after the overflow opening pressure of the relief valve is set, when the outlet oil pressure of the hydraulic pump 103 (i.e., the oil supply pressure) reaches the overflow opening pressure, the relief valve opens for overflow. As long as the relief valve continuously maintains the overflow state, the outlet oil pressure of the hydraulic pump 103 (i.e., the oil supply pressure) will always remain at the overflow opening pressure.

[0084] In Figure 6 the illustrated embodiment, the oil supply line L1 has an oil supply port P1 for supplying oil to the pumping unit 3 to be tested, and the oil supply port P1 is used to connect to the drive cylinder of the pumping unit 3 to be tested. The return oil line L2 is connected to the main return oil line L4, and the main return oil line L4 has a return oil port T1 for receiving the return oil of the pumping unit 3 to be tested, and the return oil port T1 is used to connect to the drive cylinder of the pumping unit 3 to be tested.

[0085] Referring to Figure 5 , as a specific embodiment of the fluid loading unit 2 of the present invention, the fluid loading unit 2 includes a loading circulation pipeline 204, which has a liquid inlet P2 and a liquid outlet T2 for liquid connection with the hopper 306 of the pumping unit 3 to be tested. And a second pressure detection device 202, an electro-hydraulic throttle valve 203, and an electro-hydraulic switch valve 201 are provided on the loading circulation pipeline 204. The second pressure detection device 202, the electro-hydraulic switch valve 201, and the electro-hydraulic throttle valve 203 are respectively electrically connected to the control unit. In the fluid loading unit 2, the liquid in the hopper 306 flows into the fluid loading unit 2 from the liquid inlet P2 and flows out of the liquid outlet T2 into the hopper 306 to form a circulating flow of the fluid. The electro-hydraulic switch valve 201 is used to control the on-off of the fluid in the loading circulation pipeline 204 and can withstand the high pressure during the test when detecting leaks. The electro-hydraulic throttle valve 203 is used to adjust the flow rate of the fluid in the loading circulation pipeline 204. The second pressure detection device 202 is used to monitor the fluid pressure in the loading circulation pipeline 204 in real time, and the magnitude of the fluid pressure is positively correlated with the oil pressure output by the hydraulic drive unit 1.

[0086] In this embodiment, the fluid in the fluid loading unit 2 is preferably water, and water pressure is used as the monitoring and control target, which is more in line with the simulation of the specific load conditions of the pumping unit. Compared with the method of using the hydraulic system to drive the oil pressure as the detection condition, it eliminates the detection errors caused by factors such as differences in the vehicle's hydraulic system, different return oil pressures, and different frictional resistances of the concrete piston, and the detection result is more accurate, realizing the quantitative detection of the leakage amount of the to-be-tested pumping unit 3.

[0087] In Figure 5 In the specific embodiment shown, the second pressure detection device 202 is arranged at the front end of the electronically controlled switching valve 201, and the electronically controlled switching valve 201 is arranged at the front end of the electronically controlled throttle valve 203. Among them, the electronically controlled switching valve 201 is preferably an electronically controlled ball valve. When the electronically controlled ball valve is arranged at the front end of the electronically controlled throttle valve 203, when the fluid loading unit 2 starts the circulating pump water, the electronically controlled ball valve is in a fully open state, and the electronically controlled throttle valve 203 performs throttling adjustment according to the usage requirements. When detecting the leakage of the to-be-tested pump water unit 3, the control unit controls the electronically controlled ball valve to close, and the loading circulation pipeline 204 is completely closed. At this time, the water pressure monitored by the second pressure detection device 202 is the actual test loading pressure, and the magnitude of the water pressure is positively correlated with the oil pressure output by the hydraulic drive unit 1. The above-mentioned electronically controlled ball valve can withstand the high pressure during the leakage detection process and has good sealing performance. Its arrangement at the front end of the electronically controlled throttle valve 203 can effectively avoid the problem that the electronically controlled throttle valve 203 has poor sealing during the debugging and loading process, resulting in liquid leakage and finally inaccurate detection of the water pressure by the second pressure detection device 202. In addition, multiple electronically controlled ball valves with different diameters can be connected in parallel on the branch roads of the electronically controlled ball valve and the electronically controlled throttle valve 203 of the present invention. Then, the control unit can control the opening and closing of each electronically controlled ball valve to obtain an electronically controlled ball valve group with different opening and closing combinations, so as to realize the loading requirements of different pressure loads. At this time, the electronically controlled throttle valve 203 can compensate for the pressure fine-tuning range between the working combinations of the electronically controlled ball valves, improving the fine movement performance of the fluid loading unit 2 for loading adjustment.

[0088] The above specific embodiment of the fluid loading unit 2 is only a preferred embodiment within the technical concept of the present invention. In fact, the technical concept of the fluid loading unit 2 of the present invention is to inject fluid into the hopper 306 to form a fluid pressure in the hopper 306. Inspired by the above technical concept of the present invention, the specific fluid loading form of the present invention is not limited to Figure 5 the form of forming a circulating fluid loading through the hydraulic circuit in For example, fluid can be directly injected into the hopper 306. When the to-be-tested pumping unit 3 pumps, the fluid in the hopper flows out through the valve port of the hopper 306, and then the valve port of the hopper 306 is closed during the leakage detection. A fluid pressure detection device is arranged in the hopper or at the valve port to detect the fluid pressure, etc. These simple variations all belong to the protection scope of the method of the present invention.

[0089] The above reference Figures 3 to 6 describes some typical structures and simple variant structures of the specific implementation manners of the leak detection system for the pumping unit of the present invention. The following is based on the above hydraulic structure of the leak detection system for the pumping unit and in combination with Figure 7 the specific structure of the pumping unit 3 to be tested, the specific implementation manners of the leak detection method for the pumping unit of the present invention will be described. First of all, it should be noted that in the following description, the oil supply pressure regulating device 105 is preferably an electro-hydraulic proportional relief valve. The high and low of the inlet pressure of the electro-hydraulic proportional relief valve is proportional to the magnitude of the input signal current, that is, the inlet oil pressure is controlled by the magnitude of the current of the input electromagnet. Then, different magnitudes of signal currents can be input to the electro-hydraulic proportional relief valve through the control unit to control the magnitude of the overflow opening pressure of the electro-hydraulic proportional relief valve, that is, the magnitude of the oil supply pressure of the hydraulic drive unit 1 can be controlled. The fluid is preferably water.

[0090] Specifically, the hydraulic drive unit 1 is connected to the drive cylinder 302 of the pumping unit 3 to be tested, and the fluid loading unit 2 is connected to the hopper 206 of the pumping unit 3 to be tested. After the hopper 206 is filled with water, the pumping unit 3 to be tested starts automatic pumping, so that the pumping unit 3 to be tested pushes the water into the loading circulation pipeline 204, and then returns to the hopper 206 through the loading regulating valve and the return water diffuser. It should be noted that the pumping unit 3 to be tested is tested in a horizontal posture. Then, when the hopper 306 is filled with water, the air in the pipeline system can be automatically discharged. Therefore, during the leak detection process of the pumping unit 3 to be tested, there is no need to perform an exhaust operation, thereby avoiding the cavitation phenomenon caused by the compression of air.

[0091] During the automatic pumping process of the pumping unit 3 to be tested, the second pressure detection device 202 needs to be electrically connected to the control unit. The user monitors the fluid pressure during the pumping load process in real time through the control unit, and determines the target oil supply pressure by comparing the measured fluid pressure with the standard test pressure. Specifically, when the measured fluid pressure is within the standard test pressure range, the control unit locks the set value of the input current of the current electro-hydraulic proportional relief valve, and sets the current oil supply pressure detected by the first pressure detection device 104 as the target oil supply pressure; when the measured fluid pressure is not within the standard test pressure range, since the fluid pressure is positively correlated with the oil supply pressure of the hydraulic drive unit 1, the fluid pressure can be adjusted by adjusting the electro-hydraulic proportional relief valve. Specifically, the control unit adjusts the input current of the electro-hydraulic proportional relief valve to adjust the current oil supply pressure of the hydraulic drive unit 1. When the control unit detects that the current fluid pressure feedback by the second pressure detection device 202 is within the standard test pressure range, it locks the set value of the input flow rate of the adjusted electro-hydraulic proportional relief valve, and sets the current oil supply pressure feedback by the first pressure detection device 104 as the target oil supply pressure. The method of adjusting the water load pressure through the electro-hydraulic proportional relief valve is mainly to adjust the electro-hydraulic proportional relief valve to change the magnitude of the oil supply pressure of the hydraulic drive unit 1. The pressure oil acts on the drive cylinder 302 of the pumping unit 3 to be tested, pushing the cylinder piston rod 303 to push the concrete piston 305 to pressurize the water in the pumping unit 3 to be tested. At the same time, the magnitude of the water pressure displayed by the second pressure detection device 202 is monitored in real time, and the electro-hydraulic proportional relief valve is continuously adjusted until the magnitude of the water pressure displayed by the second pressure detection device 202 is within the standard test pressure range. The above adjustment process can be automatically adjusted through the control unit, without manual frequent adjustment, which not only improves the operation efficiency, but also reduces the skill requirements for operators.

[0092] When performing leakage detection on the pumping unit 3 to be tested, the electric control switch valve 201 is closed. At this time, the concrete cylinder 304, hopper 306, S-pipe 309, concrete piston 305, wear plate 307, cutting ring 308, loading circulation pipeline 204 and electric control switch valve 201 form a water-filled closed cavity. The hydraulic drive unit 1 drives the oil cylinder piston rod 303 of the pumping unit 3 to be tested with the oil supply pressure controlled by the input current of the electro-hydraulic proportional relief valve set by the system, thereby driving the closed cavity to realize pressurization of the closed cavity. This pressure value is basically equal to the oil supply pressure value of the hydraulic drive unit 1, and the pressurization of the closed cavity is maintained for the preset pressurization duration of the system. Due to factors such as machining errors and working errors of the hydraulic system in the pumping unit 3 of the same model, during the actual leak detection process, it is also necessary to adjust the oil supply pressure of the hydraulic drive unit 1 in real time so that the current oil supply pressure is basically consistent with the target oil supply pressure set by the system. Specifically, the adjustment process is mainly as follows: The control unit inputs the set input current to the electro-hydraulic proportional relief valve, and the opening pressure of the electro-hydraulic proportional relief valve is the pressure value corresponding to the current input current. The hydraulic pump 103 starts to operate, causing the electro-hydraulic proportional relief valve to open and overflow. In the state where the electro-hydraulic proportional relief valve is open and overflowing, the control unit detects whether the current oil supply pressure feedback by the first pressure detection device 104 is within the system preset target oil supply pressure range. If not, the control system needs to calculate the difference between the current oil supply pressure and the target oil supply pressure, and adjust the magnitude of the input current of the electro-hydraulic proportional relief valve. At the same time, monitor the current oil supply pressure feedback by the first pressure detection device 104, and judge in real time whether the interpolation between the two is within the preset error range. If so, stop the adjustment, so that the hydraulic drive unit 1 drives the drive oil cylinder 302 of the pumping unit 3 to be tested with the adjusted oil supply pressure.

[0093] The hydraulic drive unit 1 drives the cylinder piston rod 303 of the drive cylinder 302 to push the concrete piston 305 in the concrete cylinder 304 to move at a preset target oil supply pressure, and compresses the water in the sealed cavity at the preset target oil supply pressure. Due to the incompressibility of water, under the pressure of the concrete piston 305, the water can only leak to the mating clearance between the spectacle plate 307 and the cutting ring 308. As the water leaks, the volume of water in the sealed cavity will gradually decrease. Thus, the cylinder piston rod 303 of the drive cylinder 302 will continuously extend to push the concrete piston 305 to compress the sealed cavity. It can be understood that if there is no clearance between the spectacle plate 307 and the cutting ring 308, no leakage will occur, then the cylinder piston rod 303 will remain in place. If there is leakage, the length of the cylinder piston rod 303 before and after leakage will change, and this length is the displacement of the cylinder piston rod 303. In addition, the preset pressurization duration can be flexibly adjusted according to the test conditions and is not specifically limited in this embodiment. During the preset pressurization duration when the sealed cavity is pressurized, the control unit reads the displacement detection device 301 installed on the drive cylinder 302 and detects the displacement of the cylinder piston rod 303 in real time through the displacement detection device 301. Preferably, the displacement detection device 301 in this embodiment can be a laser displacement sensor. The laser emitter projects visible red laser onto the surface of the cylinder piston rod 303 through a lens. The laser reflected by the object is received by the CCD linear camera and then the distance between the sensor and the surface of the cylinder piston rod 303 is calculated by the digital signal processor, and this distance signal is transmitted to the control unit. The control unit automatically calculates the displacement change of the cylinder piston rod 303 before and after pressurization. It can be imagined that other devices capable of measuring distance are also feasible and are within the protection scope of the present invention.

[0094] The control unit inputs the obtained displacement, the characteristic parameters of the drive cylinder 302 and the concrete cylinder 304 of the to-be-tested pumping unit 3, etc. into the formula preset in the system to obtain the leakage amount, and at the same time compares this leakage amount with the maximum allowable leakage value preset in the system, and outputs the judgment result of whether the to-be-tested pumping unit 3 is qualified. After the above steps are completed, the electro-control switch valve 201 and the electro-proportional overflow valve return to the open state, and the hydraulic system shuts down and unloads to avoid generating instantaneous high pressure during the next test.

[0095] As can be seen from the above description, the advantages of the present invention are as follows: In the hydraulic drive unit 1 of the leak detection system for the pumping unit of the present invention, there is an electronically controllable oil supply pressure regulating device 105 and a first pressure detection device 104. Thus, the automatic regulation of the oil supply pressure of the hydraulic drive unit 1 can be achieved through the control unit. In the fluid loading unit 2, multiple electronically controlled on-off valves 201 with different diameters can be connected in parallel on the branch paths of the electronically controlled switching valve 201 and the electronically controlled throttle valve 203. Then, through the control unit, the opening and closing of each electronically controlled on-off valve 201 can be controlled to obtain an electronically controlled on-off valve group with different opening and closing combinations, so as to realize the loading requirements of different pressure loads. Therefore, for a single model of the pumping unit, the leak detection under different working conditions (i.e., different load water pressures) can automatically generate its load water pressure - leakage amount curve through the control unit, which can effectively help users prevent excessive leakage caused by using too large a load, thereby avoiding the situation where the equipment fails. In addition, the leak detection system for the pumping unit of the present invention can perform separate leak detection on the pumping unit 3 to be tested in a horizontal posture. Compared with detecting in an inclined posture on the whole vehicle, after the hopper 306 is filled with liquid, the air in the pipeline system can be automatically discharged, and there is no need to perform an exhaust operation during the leak detection process, thus avoiding the cavitation phenomenon caused by air compression. Moreover, compared with testing on the whole vehicle, a large amount of disassembly and assembly work of the conveying pipes is reduced. Additionally, the leak detection method for the pumping unit of the present invention can obtain its detection parameters (such as the pressure setting value of the oil supply pressure regulating device 105, etc.) through the initial debugging of a single model of the pumping unit. Then, when performing leak detection on the same model of the pumping unit, the detection parameters can be directly called for detection. For different models of the pumping unit, the oil supply pressure of the hydraulic drive unit 1 can be adjusted by changing the signal current input to the oil supply pressure regulating device 105 through the control unit, thus meeting the requirement of automatically adjusting detection parameters for different models of the pumping unit. For the same model of the pumping unit, under the detection conditions of different load water pressures, the oil supply pressure of the hydraulic drive unit 1 can also be adjusted by changing the signal current input to the oil supply pressure regulating device 105 through the control unit, thus meeting the requirement of automatically adjusting detection parameters for the same model of the pumping unit under different load water pressure conditions, avoiding the operation of manually and frequently adjusting the pressure of the hydraulic drive unit 1, improving the operation efficiency, reducing the skill requirements of the operators, and also meeting the requirement of flexible production.

[0096] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0097] In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present invention will not separately describe various possible combinations.

[0098] Furthermore, any combination can be made among the various different embodiments of the present invention, as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A leak detection method for a pumping unit, characterized in that, It includes the following steps: First, fill the hopper (306) with fluid. When the pumping unit to be tested (3) starts pumping, a fluid pressure is formed in the hopper (306). Second, obtain the current fluid pressure and adjust to establish the target oil supply pressure according to the current fluid pressure. Third, close the discharge port of the hopper (306), drive the drive cylinder (302) of the pumping unit to be tested (3) with the target oil supply pressure, and maintain the preset pressurization duration. Fourth, record the displacement advanced by the drive cylinder (302) within the preset pressurization duration. Fifth, conduct a leakage analysis on the pumping unit to be tested (3) based on the displacement and determine whether there is leakage. Among them, in the second step, when the current fluid pressure is within the standard test pressure range, obtain the current oil supply pressure and set the current oil supply pressure as the target oil supply pressure; when the current fluid pressure is not within the standard test pressure range, adjust the oil supply pressure to make the current fluid pressure within the standard test pressure range, obtain the current oil supply pressure, and set the current oil supply pressure as the target oil supply pressure.

2. The leak detection method for the pumping unit according to claim 1, characterized in that, The target oil supply pressure is adjusted and established by the oil supply pressure regulating device (105), and the third step includes: a. Set the overflow opening pressure of the oil supply pressure regulating device (105) as the target oil supply pressure through the control unit, and make the oil supply pressure regulating device (105) open the overflow by the operation of the hydraulic pump (103). b. In the state where the oil supply pressure regulating device (105) opens the overflow, monitor the current oil supply pressure in real time through the first pressure detection device (104), compare the difference between the monitored current oil supply pressure and the target oil supply pressure, and adjust the oil supply pressure regulating device (105) through the control unit until the monitored current oil supply pressure is equal to the target oil supply pressure.

3. The leak detection method for the pumping unit according to claim 1, characterized in that, The fourth step includes reading, through the control unit, the displacement detection device (301) installed on the drive cylinder (302), and detecting the displacement of the cylinder piston rod (303) in real time through the displacement detection device (301).

4. The leak detection method for the pumping unit according to claim 1, wherein, The fifth step includes calculating the leakage amount according to the characteristic parameters of the driving oil cylinder (302) and the concrete cylinder (304) of the pumping unit (3) to be measured, and the leakage amount is Q = 0.25πD 2 L0, and making a qualified judgment by comparing with the maximum allowable leakage value, where D is the inner diameter of the concrete cylinder and L0 is the displacement.

5. A leak detection system for a pumping unit, characterized in that, The leak detection method using the pumping unit according to any one of claims 1 to 4, comprising a hydraulic drive unit (1) for connecting to the pumping unit to be tested (3) and a fluid loading unit (2) for adding fluid to the pumping unit to be tested (3), wherein the hydraulic drive unit (1) includes a hydraulic pump (103) connected to an oil supply circuit (L1), a cartridge valve (107), a safety valve (106), and an oil supply pressure regulating device (105). A first working oil port (A) of the cartridge valve (107) is connected to the oil supply circuit (L1), a second working oil port (B) is connected to an oil return circuit (L2), and a control oil port (X) is connected to an oil supply control circuit (L3). The oil supply pressure regulating device (105) is provided on the oil supply control circuit (L3). The connection point of the control oil port (X) of the cartridge valve (107) on the oil supply control circuit (L3) is before the inlet port (C) of the oil supply pressure regulating device (105). One end of the oil supply control circuit (L3) is connected to the oil supply circuit (L1), and the other end is connected to the oil return circuit (L2). One end of the safety valve (106) is connected to the oil supply control circuit (L3), and the other end is connected to the oil return circuit (L2). The oil supply pressure regulating device (105) is electrically connected to a control unit to adjust the oil supply pressure of the hydraulic drive unit (1) by adjusting the oil supply pressure regulating device (105) through the control unit. A first pressure detection device (104) is provided on the oil supply circuit (L1), and the first pressure detection device (104) is electrically connected to the control unit. The pumping unit to be tested (3) includes a drive cylinder (302) and a hopper (306). The drive cylinder (302) is connected to the hydraulic drive unit (1), and the hopper (306) is connected to the fluid loading unit (2).

6. The leak detection system for a pumping unit according to claim 5, characterized in that, The fluid loading unit (2) includes a loading circulation pipeline (204) having a liquid inlet port (P2) and a liquid outlet port (T2) for liquid circuit connection with the hopper (306) of the pumping unit to be tested (3). A second pressure detection device (202), an electronically controlled throttle valve (203), and an electronically controlled switching valve (201) are provided on the loading circulation pipeline (204). The second pressure detection device (202), the electronically controlled switching valve (201), and the electronically controlled throttle valve (203) are respectively electrically connected to the control unit.

7. The leak detection system for the pumping unit according to claim 5, characterized in that, The first pressure detection device (104) is provided after the connection point of the oil supply control circuit (L3) and the oil supply circuit (L1).

8. The leak detection system for a pumping unit according to claim 5, wherein The oil supply pressure regulating device (105) is an electro-hydraulic proportional relief valve. The overflow pressure regulation of the oil supply circuit (L1) is achieved through the electro-hydraulic proportional relief valve. The electro-hydraulic proportional relief valve changes the overflow opening pressure through the control of the control unit to adjust the oil supply pressure of the hydraulic drive unit (1).

9. The leak detection system for the pumping unit according to claim 5, characterized in that, The oil supply circuit (L1) has an oil supply port (P1) for supplying oil to the pumping unit (3) to be tested, the oil return circuit (L2) is connected to the main oil return circuit (L4), and the main oil return circuit (L4) has an oil return port (T1) for receiving the oil returned from the pumping unit (3) to be tested.

10. The leak detection system for the pumping unit according to claim 6, wherein The fluid loading unit (2) is a water loading unit.

11. The leak detection system for the pumping unit according to claim 10, characterized in that, The second pressure detection device (202) is provided at the front end of the electronically controlled switching valve (201), and the electronically controlled switching valve (201) is provided at the front end of the electronically controlled throttle valve (203).

12. The leak detection system for the pumping unit according to claim 11, wherein The electronically controlled switching valve (201) is an electronically controlled ball valve.

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