Hydraulic tappet leakage and sinking time testing device and detection method

Abstract

The invention discloses a hydraulic tappet leak-down time testing device and method, and belongs to the field of diesel engine design. The hydraulic tappet leak-down time testing device comprises an actuator for outputting force to compress a hydraulic tappet; the control unit is used for obtaining pressure, temperature and displacement signals in the testing process, controlling an actuator to complete required actions, comparing and analyzing a testing result and a target value, judging whether a product is qualified or not, and outputting a pressure value, a leakage and sinking time value and a temperature value to an upper computer at the same time; and the upper computer records and displays the data uploaded by the control unit and is used for man-machine interaction to send an instruction to the control unit. According to the invention, the accurate test of the leakage and sinking time of the hydraulic tappet is completed, the test cost is saved, the test period is shortened, and advanced verification before whole engine examination is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of diesel engine design, and relates to hydraulic tappet testing, in particular to a hydraulic tappet leakage and sinking time testing device and detection method. BACKGROUND

[0002] The valve train is one of the core subsystems of an engine, controls the entire air exchange process of the engine, and has an extremely important influence on the power, economy, vibration and noise of the engine. The hydraulic tappet makes the valve train work in a zero-clearance state in real time by adjusting its length, effectively reduces the impact load when the valve is closed, relieves the wear of parts, realizes the maintenance-free of the valve train in the whole life cycle, and at the same time, can reduce the working noise of the valve train, improve the air charging efficiency, and improve the working quality of the engine.

[0003] The leakage and sinking time is an important parameter affecting the working performance of the hydraulic tappet. If the hydraulic tappet sinks too slowly, it will cause abnormal noise during starting; if it sinks too fast, the valve will not be able to open or close according to the design state, resulting in disorder of the valve timing. The length of the leakage and sinking time can reflect the size of the gap between the plunger and the shell in the hydraulic tappet, and the oil leakage amount of the hydraulic tappet during valve opening and closing.

[0004] Accurate acquisition of the leakage and sinking time of the hydraulic tappet and selection of the hydraulic tappet with appropriate leakage and sinking time are crucial for the design and development of new valve trains. Therefore, it is necessary to carry out research on the leakage and sinking time testing and control technology of the hydraulic tappet, which can provide technical support for sample development, engine bench test and subsequent application. SUMMARY

[0005] The present application is to solve the above problems in the prior art, and proposes a hydraulic tappet leakage and sinking time testing device and detection method. In view of the technical problems in the background art, a plurality of sensors are arranged, the pressure, temperature and distance are strictly controlled, the detection displacement accuracy is ensured, the leakage and sinking time is calculated in time, the leakage and sinking time detection result is displayed, and it is quickly determined whether the hydraulic tappet is qualified.

[0006] The hydraulic tappet leakage and sinking time testing device comprises an actuator, and the output force is used to compress the hydraulic tappet; A control unit obtains the pressure, temperature and displacement signals in the testing process, controls the actuator to complete the required action, compares and analyzes the test result with the target value, determines whether the product is qualified, and outputs the pressure value, leakage and sinking time value and temperature value to an upper computer; The upper computer records and displays the data uploaded by the control unit, and is used for human-computer interaction to send instructions to the control unit.

[0007] Further, the actuator is a cylinder, and a gas storage tank is arranged between the total gas source and the cylinder, for ensuring stable input of gas pressure in the cylinder; during detection of the part, a pressure sensor arranged in the cylinder is used to display the detection pressure in real time, and a displacement sensor is used to control the cylinder to reach a preset detection position, detect the displacement, calculate the leakage and sinking time, and display the leakage and sinking time detection result on the upper computer.

[0008] Further, a pneumatic three-way joint is arranged between the gas storage tank and the cylinder, and the three-way joint comprises, in sequence from the gas storage tank, a filter, a pressure reducing valve, and an oil atomizer; the filter is used to filter impurities, the pressure reducing valve is used to stabilize the pressure, and the oil atomizer is used to atomize lubricating oil to lubricate the pneumatic elements.

[0009] Further, two five-way two-position electromagnetic valves are connected in parallel in the gas circuit to control the cylinder to perform three actions, including extension, retraction, and stopping at an arbitrary position.

[0010] Further, the displacement sensor is used to send a signal when the hydraulic tappet is compressed to a detection start position, the control unit records the time as T1, the displacement sensor is used to send a signal when the hydraulic tappet is compressed to a detection end position, the control unit records the time as T2, and the control unit calculates the leakage and sinking time ∆T = T2-T1.

[0011] Further, the temperature sensor is used to monitor the internal temperature of the test device in real time, feed back a temperature signal to the control unit, and adjust the temperature to a required temperature range by the temperature control unit.

[0012] Further, the upper computer comprises an indicator light, which is green when the leakage and sinking time of the sample is within a preset qualified range, and is red when the leakage and sinking time of the sample is not within the preset qualified range, and the test ends.

[0013] The method for detecting the leakage and sinking time of a hydraulic tappet comprises the following steps: (a) opening a one-way ball valve by using an oil injection needle and repeatedly pressing the hydraulic tappet to fill the hydraulic tappet with oil until the hydraulic tappet is in a rigid state, and starting detection of the leakage and sinking time of the hydraulic tappet; (b) recording, by the test device, the time when the hydraulic tappet is compressed to a detection start position as T1, recording the time when the hydraulic tappet is compressed to a detection end position as T2, and calculating the leakage and sinking time ∆T = T2-T1, which is the leakage and sinking time of the hydraulic tappet passing through a preset displacement; (c) measuring the leakage and sinking time ∆T data of multiple angles of the hydraulic tappet, performing arithmetic average processing, and taking the average value as the leakage and sinking time of the sample; (d) if the leakage and sinking time of the sample is within a preset qualified range, the indicator light is green, indicating that the sample is qualified; otherwise, the indicator light is red, indicating that the sample is unqualified, and the test ends.

[0014] Further, in step (c), the tappet is rotated 4 times in a clockwise direction, each time by 90°, and the ΔT data of the four direction points are recorded as t1, t2, t3, t4. The four data t1-t4 are arithmetically averaged by using the arithmetic average method, and the average value is recorded as the leakage sinking time of the sample.

[0015] Compared with the prior art, the hydraulic tappet leakage sinking time testing device and detection method has the following beneficial effects: (1) The application has the advantages of controllable test period and environmental factors, can truly measure the time required for the hydraulic tappet to be compressed to a predetermined displacement, evaluate whether the hydraulic tappet leakage sinking time meets the whole machine performance requirement, facilitate subsequent design optimization, not only save test cost and shorten test period, but also realize advanced verification before engine whole machine test.

[0016] (2) The application sets multiple sensors, strictly controls pressure, temperature and distance, ensures the accuracy of the detected displacement, calculates the leakage sinking time in time, displays the leakage sinking time detection result, and quickly determines whether the hydraulic tappet is qualified.

[0017] (3) The accurate testing of the hydraulic tappet leakage sinking time in the application indirectly represents the size of the gap between the plunger and the shell in the hydraulic tappet, and the amount of oil leakage during the opening and closing of the valve, which is particularly important for the design and development of new valve train mechanisms. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which form a part of this application, are intended to provide further understanding of the application and are incorporated herein for a purpose of explanations of the application and are not intended as an improper limitation to the application. In the drawings: Figure 1 is a structural schematic diagram of the hydraulic tappet in the prior art; Figure 2 is a structural schematic diagram of the hydraulic tappet leakage sinking time testing device of the application; Figure 3 is a schematic diagram of the cylinder control in the hydraulic tappet leakage sinking time testing device of the application; Figure 4 is a schematic diagram of the hydraulic tappet leakage sinking time testing device of the application; Figure 5 is a schematic diagram of the hydraulic tappet leakage sinking time detection method of the application.

[0019] BRIEF DESCRIPTION OF DRAWINGS 1, support gasket; 2, plunger; 3, plunger sleeve; 4, one-way ball valve; 5, ball valve retainer; 6, ball valve spring; 7, plunger return spring; 8, elephant foot; 9, rocker arm; 10, low-pressure oil cavity; 11, high-pressure oil cavity; 101. Actuator; 102. Control unit; 103. Host computer; 104. Pressure sensor; 105. Displacement sensor; 106. Temperature sensor; 107. Five-way two-position solenoid valve; 108. Pneumatic triplet; 109. Air tank. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0021] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] In this application, common terms are explained as follows.

[0023] Figure 1 This is a schematic diagram of the original hydraulic tappet structure, mainly composed of a support gasket 1, plunger 2, plunger sleeve 3, one-way ball valve 4, ball valve retainer 5, ball valve spring 6, plunger return spring 7, and piston foot 8, mounted on the rocker arm 9. The hydraulic tappet's sinking time mainly depends on the fit clearance between plunger 2 and plunger sleeve 3, the low-pressure oil chamber 10, and the high-pressure oil chamber 11. When the engine is running, engine oil enters from the cylinder head oil passage... Figure 1 The original hydraulic tappet shown has a low-pressure oil chamber 10, in which... Under the action of oil pressure, the one-way ball valve 4 opens, and the oil immediately fills the high-pressure oil chamber 11 under the plunger; when the oil pressure in the high-pressure oil chamber 11 is equal to the oil pressure in the low-pressure oil chamber 10, the one-way ball valve 4 returns to its closed position; the plunger 2 rises under the action of oil pressure and plunger return spring 7, thereby eliminating valve clearance and realizing automatic compensation of valve clearance. Regarding the conventional knowledge in this part, this application has also mentioned and disclosed it in previous patents, patent number: 2022107437748.

[0024] The hydraulic tappet leakage time refers to the time taken by the hydraulic tappet to produce a certain displacement after the internal oil leaks through the gap after being subjected to pressure. It is not a fixed value, but an allowable interval; the leakage time is too short (leakage is too fast): the tappet becomes soft at high speed, the valve lift is insufficient, the power is reduced, and the continuous noise is generated; the leakage time is too long (leakage is too slow): the tappet is too rigid, the damping effect is poor at low speed, the noise similar to the mechanical tappet is generated, the impact is large, and the wear is fast; in a good hydraulic tappet design scheme, the leakage time parameter can dynamically adapt to changes under all specified engine operating conditions, and the performance is always maintained in the optimal balance zone.

[0025] The pneumatic three-way component is composed of three parts in sequence: filter, pressure reducing valve and oil atomizer. The sequence is fixed and cannot be reversed. The filter is used to remove liquid water, oil droplets and solid particle contaminants in compressed air. The pressure reducing valve adjusts and stabilizes the upstream fluctuating and higher pressure to a set lower outlet pressure and maintains the pressure stable. The oil atomizer atomizes the lubricating oil into small oil droplets and delivers them to the pneumatic components that need lubrication with the airflow. Through "filtering impurities first, stabilizing pressure second, and then providing lubrication", the original and rough compressed air is "finished" into a high-quality power source meeting the requirements of the equipment.

[0026] As shown in Figures 2-5 The hydraulic tappet leakage time test device includes an actuator 101 that outputs force for compressing the hydraulic tappet. The actuator 101 in the application can also use an oil cylinder or an electric push rod that can meet the output force requirement. Under the premise of considering cost and other factors, the application selects the cylinder as the actuator 101. A control unit 102 obtains pressure, temperature and displacement signals during the test, controls the actuator 101 to complete the required action, compares and analyzes the test results with the target value, determines whether the product is qualified, and outputs the pressure value, leakage time value and temperature value to an upper computer 103. The control unit 102 in the application is a PLC controller. The upper computer 103 records and displays the data uploaded by the control unit 102, and is used for human-computer interaction to send instructions to the control unit 102. Figure 2As shown, the host computer 103 in the present application is a display screen that displays pressure values, sink time values and temperature values in real time, ensuring that various parameters meet the environmental requirements of testing. If the feedback data does not meet the requirements, the parameters are adjusted to meet the requirements, meeting the demand for controllable environmental factors. In the case of unsuitable temperature, air conditioners are added in the test environment to meet the temperature requirements, and the pressure can be adjusted by setting and adjusting the gas tank 109. In more detail, the host computer 103 includes an input module, a CPU control module and an output module. The input module is used to receive sensor signals and button signals from the control unit 102. The CPU control module is used to record and calculate data. The output module is used to display data and send drive signals. The motor is controlled by a servo driver to return to the original position for testing, and the output module controls the electromagnetic valve to control the actuator 101 to move.

[0027] Preferably, the actuator 101 is a gas cylinder, and a gas tank 109 is provided between the total gas source and the gas cylinder to ensure stable input of gas pressure in the gas cylinder. During detection of the part, the pressure sensor 104 provided in the gas cylinder displays the detection pressure in real time, and the displacement sensor 105 controls the gas cylinder to reach the preset detection position to detect the displacement and calculate the sink time. The sink time detection result is displayed by the host computer 103. The pressure sensor 104 is used to ensure that the applied pressure meets the actual working condition simulation of the hydraulic tappet, ensuring the accuracy of the basic conditions of the test. The displacement sensor 105 is used to accurately control the position of the gas cylinder, further ensuring the accuracy of the simulation test.

[0028] Preferably, a pneumatic three-way joint 108 is provided between the gas tank 109 and the gas cylinder. From the gas tank 109, there are a filter, a pressure reducing valve and an oil atomizer in sequence. The filter is used to filter impurities, the pressure reducing valve is used to stabilize the pressure, and the oil atomizer is used to atomize lubricating oil to lubricate the pneumatic element. The entire part setting ensures the cleanliness of the gas source, which is conducive to the accuracy and stability of the action of the gas cylinder.

[0029] Preferably, the gas path is controlled by two five-way two-position solenoid valves 107 in parallel to control the cylinder action, including extension, retraction and intermediate position stop three actions, so the setting can meet the intermediate test requirements, using two five-way two-position solenoid valves 107 to control the cylinder, including state one: the piston rod extends, the electromagnetic valve 1 is powered on, the gas path is conducted, and the compressed air enters the cylinder rodless cavity. The electromagnetic valve 2 is de-energized, the gas path is conducted, and the cylinder rod cavity is connected with the atmosphere. State two: the piston rod retracts, the electromagnetic valve 1 is de-energized, the gas path is conducted, and the cylinder rodless cavity is connected with the atmosphere. The electromagnetic valve 2 is powered on, the gas path is conducted, and the compressed air enters the cylinder rod cavity. State three: stop at any position (mid-position closed), the electromagnetic valve 1 and the electromagnetic valve 2 are de-energized at the same time. The gas path of the two valves returns to the initial state, and the gas inlet and exhaust of the rodless cavity and the rod cavity of the cylinder are all closed, and the piston is "locked" in the current position by the gas pressure and cannot be moved. It can realize accurate intermediate position stop, high safety performance and more flexible control.

[0030] Preferably, it also includes a displacement sensor 105, which sends a signal when the hydraulic tappet is compressed to the detection start position, and the control unit 102 records the time as T1. The control unit 102 records the time as T2 when the hydraulic tappet is compressed to the detection end position, and the control unit 102 calculates the leakage time ∆T = T2-T1. The calculation is performed by a calculation module and then fed back to the display screen.

[0031] Preferably, it also includes a temperature sensor 106 for real-time monitoring of the internal temperature of the test device, feeding back the temperature signal to the control unit 102, and adjusting the temperature to the required temperature range for testing through the temperature control unit. According to the test requirements, adjust the temperature value through external equipment such as air conditioner until the test requirements are met.

[0032] Preferably, the host computer 103 includes an indicator light. If the sample leakage time is within the expected set qualified range, the indicator light is green, indicating that it is qualified. Otherwise, the indicator light is red, indicating that it is unqualified. The test is over, and the intuitive display is more convenient to read.

[0033] The method for detecting the leakage time of a hydraulic tappet uses a hydraulic tappet leakage time test device, which includes the following steps: (a) open the one-way ball valve with an oil injection needle and press repeatedly to fill the hydraulic tappet with oil until the hydraulic tappet is in a rigid state, and then start the hydraulic tappet leakage time detection; (b) The test device automatically records the time when the hydraulic tappet is compressed to the detection start position as T1, and the time when the hydraulic tappet is compressed to the detection end position as T2. The leakage time ∆T = T2-T1 is the leakage time detected by the preset displacement; (c) Measure the leakage time ∆T data of multiple angles of the hydraulic tappet, and perform arithmetic average processing. The average value is recorded as the leakage time of the sample; (d) If the sedimentation time of the sample is within the expected set acceptable range, the indicator light will turn green to indicate that it is qualified; otherwise, the indicator light will turn red to indicate that it is unqualified, and the test will end.

[0034] Preferably, in step (c), the tappet is rotated clockwise 4 times, each time by 90°, and the ∆T data of the four directional points are measured and recorded as t1, t2, t3, and t4. The arithmetic mean method is used to perform arithmetic mean processing on the four data of t1 to t4, and this average value is recorded as the settling time of the sample.

[0035] More specifically, after the operator presses the automatic start button on the host computer 103, the entire device begins operation. The temperature sensor 106 feeds back the temperature to the control center to determine if the temperature is within the set range. If not, adjustments are made until the temperature feedback value meets the requirements, then proceeding to the next step. After the motor returns to its original position, the one-way ball valve is opened with the oil injection needle and repeatedly pressed to fill the hydraulic tappet with oil until the hydraulic tappet is in a rigid state and positioned at the sinking test point. The preliminary preparation work is completed. Then, the control unit 102 prepares to apply pressure, adjusts the test pressure, and when the actual measured pressure meets the preset pressure ±50N, the timing test begins. The test, under the premise of ensuring that the displacement meets the preset displacement, determines whether the settling time is within the required range. If the settling time is within the range, the hydraulic tappet settling time is qualified and marked. Unqualified hydraulic tappet products are pushed out and enter the unqualified discharge position. The entire structure realizes automated control, high precision, and has the advantages of controllable test cycle and environmental factors. It can accurately measure the time required for the hydraulic tappet to compress to the predetermined displacement, evaluate whether the hydraulic tappet settling time meets the performance requirements of the whole machine, and facilitate subsequent design optimization. It not only saves test costs and shortens the test cycle, but also realizes advanced verification before the engine whole machine test.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0037] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A hydraulic tappet settling time testing device, characterized in that: Includes an actuator that outputs force to compress the hydraulic tappet; The control unit obtains pressure, temperature, and displacement signals during the test process, controls the actuator to complete the required actions, compares and analyzes the test results with the target values, determines whether the product is qualified, and outputs pressure, venting time, and temperature values ​​to the host computer. The host computer records and displays the data uploaded by the control unit, and is used for sending commands to the control unit for human-machine interaction.

2. The hydraulic tappet settling time testing device according to claim 1, characterized in that: The actuator is a cylinder. An air tank is installed between the main air source and the cylinder to ensure stable air pressure input in the cylinder. During the part inspection process, the pressure sensor installed in the cylinder displays the detection pressure in real time, and the displacement sensor controls the cylinder to reach the preset detection position, detects the displacement, calculates the settling time, and displays the settling time detection result on the host computer.

3. The hydraulic tappet settling time testing device according to claim 2, characterized in that: A pneumatic triplet is installed between the air tank and the cylinder. From the air tank, the triplet consists of a filter, a pressure reducing valve, and an oil mist lubricator. The filter is used to filter impurities, the pressure reducing valve is used to stabilize the pressure, and the oil mist lubricator is used to atomize lubricating oil to lubricate the pneumatic components.

4. The hydraulic tappet settling time testing device according to claim 2, characterized in that: The cylinder's movement is controlled by two parallel five-way two-position solenoid valves in the air circuit, including three actions: extension, retraction, and stopping at any intermediate position.

5. The hydraulic tappet settling time testing device according to claim 1, characterized in that: The system includes a displacement sensor. When the hydraulic tappet is compressed to the detection start position, it sends a signal. The control unit records the time as T1. When the hydraulic tappet is compressed to the detection end position, it sends a signal. The control unit records the time as T2. The control unit calculates the settling time ∆T = T2 - T1.

6. The hydraulic tappet settling time testing device according to claim 1, characterized in that: It also includes a temperature sensor for real-time monitoring of the internal temperature of the testing device, feeding back the temperature signal to the control unit, and adjusting the temperature to the required range for testing via the temperature control unit.

7. The hydraulic tappet settling time testing device according to claim 1, characterized in that: The host computer includes indicator lights. If the sample's settling time is within the expected set range, the indicator light will turn green to indicate that it is qualified; otherwise, the indicator light will turn red to indicate that it is unqualified, and the test will end.

8. A method for detecting the settling time of a hydraulic tappet, characterized in that: Use the hydraulic tappet settling time testing device according to any one of claims 1-7.

9. The method for detecting the settling time of a hydraulic tappet according to claim 8, characterized in that: The steps include: (a) opening the one-way ball valve with the injection needle and repeatedly pressing it to fill the hydraulic tappet with oil until the hydraulic tappet is in a rigid state, and then starting the hydraulic tappet settling time test. (b) The testing device automatically records the time when the hydraulic tappet is compressed to the detection start position as T1, the time when the hydraulic tappet is compressed to the detection end position as T2, and the sinking time ∆T=T2-T1, which is the sinking time when the detection passes through the preset displacement. (c) Measure the settling time ∆T data of the hydraulic tappet at multiple angles, perform arithmetic average processing, and record this average value as the settling time of the sample; (d) If the sedimentation time of the sample is within the expected set acceptable range, the indicator light will turn green to indicate that it is qualified; otherwise, the indicator light will turn red to indicate that it is unqualified, and the test will end.

10. The method for detecting the settling time of a hydraulic tappet according to claim 9, characterized in that: In step (c), the tappet is rotated clockwise 4 times, each time by 90°, and the ∆T data of the four points are measured and recorded as t1, t2, t3, and t4. The arithmetic mean method is used to process the four data of t1 to t4, and this average value is recorded as the settling time of the sample.

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