A hydraulic spool sticking force measuring device and a clearance thermal deformation variable measuring method

Abstract

The application discloses a kind of hydraulic valve core sticking force measuring device and clearance thermal deformation variable measuring method, belong to valve device field.Device includes oil tank and test hydraulic valve;Oil tank is connected with the import of test hydraulic valve by being provided with the oil inlet line of heater, and the outlet of test hydraulic valve is connected with oil tank by being provided with the oil outlet line of condenser;Valve core one end of test hydraulic valve is ferromagnetic material, outside is provided with electromagnet for making it reset, and the other end of valve core is provided with fixing piece, and fixing piece is connected with displacement actuator capable of opening valve core by traction rope.The application measures thermal sticking force under different temperature and clearance, establishes the fitting formula of the rate of change of sticking force with temperature and clearance, and then obtains the thermal deformation amount of fit clearance under certain temperature.The application can measure valve core sticking force under multiple factors and coupling effect, and through the relationship curve diagram of the rate of change of sticking force with temperature and clearance, the thermal deformation variable of fit clearance can be indirectly and conveniently obtained.

Description

Technical Field

[0001] This invention belongs to the field of valve devices, and specifically relates to a hydraulic valve core sticking force measuring device and a method for measuring gap thermal deformation. Background Technology

[0002] Hydraulic valves primarily rely on the rotation or translation of the valve core to control the flow direction and cross-sectional area of ​​the medium. When the resistance experienced by the valve core is too great, the valve's opening and closing response time increases, the valve core movement becomes uneven, and it may even prevent the valve core from moving, causing the valve to lose its operational capability. This phenomenon is known as valve core jamming. Hydraulic valve core jamming is caused by various factors, primarily thermal jamming and particulate jamming: 1) The viscosity of the fluid generates heat, reducing the clearance between the valve body and the valve core, thus causing valve core jamming; 2) Contaminant particles trapped in the valve's clearance are also trapped. Therefore, to prevent hydraulic valve core jamming, a reasonable design of the clearance is crucial.

[0003] Measuring the valve core retaining force and predicting changes in the fit clearance based on this force is fundamental to designing the optimal fit clearance. Currently, existing retaining force measuring devices cannot capture temperature-induced changes in the fit clearance, thus providing insufficient guidance for determining its value. Therefore, it is necessary to measure the temperature-induced thermal deformation of the clearance to provide a valuable reference for designing the fit clearance between the hydraulic valve body and valve core. Summary of the Invention

[0004] The purpose of this invention is to overcome the deficiencies in the prior art and provide a hydraulic valve core sticking force measuring device and a method for measuring clearance thermal deformation. This invention measures the hydraulic valve core sticking force under multiple factors and their coupling, and indirectly measures the clearance thermal deformation caused by temperature, providing a valuable reference for the design of the fit clearance between the hydraulic valve body and valve core.

[0005] The specific technical solution adopted in this invention is as follows:

[0006] In a first aspect, the present invention provides a hydraulic valve core sticking force measuring device, comprising an oil tank and a test hydraulic valve; the oil tank is connected to the inlet of the test hydraulic valve through an oil inlet pipe equipped with a heater, and the outlet of the test hydraulic valve is connected to the oil tank through an oil outlet pipe equipped with a condenser; one end of the valve core of the test hydraulic valve is made of ferromagnetic material, and an electromagnet for resetting it is provided on the outside; the other end of the valve core is provided with a fixing member, and the fixing member is externally connected to a displacement actuator that can open the valve core through a traction rope; the displacement actuator is provided with a tension / compression sensor for measuring the magnitude of the tension force.

[0007] Preferably, the fixing component is a lifting eye bolt, and the traction rope is a steel wire rope.

[0008] Preferably, both the displacement actuator and the tension / compression sensor are connected to the data acquisition system.

[0009] Preferably, the electromagnet is equipped with a linear displacement sensor for measuring the valve core opening.

[0010] Preferably, along the oil flow direction, the oil inlet pipeline is sequentially equipped with a suction pump, a first check valve, a first filter, a reversing valve, a heater, a second check valve, a flow meter, a pressure gauge, and a thermometer; the oil outlet pipeline is connected to the oil tank after passing through the reversing valve.

[0011] Furthermore, the oil inlet pipeline between the suction pump and the first check valve is also connected to the oil tank via two pipelines equipped with an overflow valve and a safety valve, respectively.

[0012] Preferably, both the electromagnet and the displacement actuator are located outside the valve body of the test hydraulic valve.

[0013] Secondly, the present invention provides a method for measuring the gap thermal deformation using any of the hydraulic valve core sticking force measuring devices described in the first aspect, as follows:

[0014] S1: Before the measurement begins, determine the electromagnetic force F of the electromagnet. 电 Subsequently, with no oil flowing into the test hydraulic valve, the valve core is driven by the displacement actuator to move at a constant speed in the opening direction. At this time, the force value of the tension / compression sensor is F1; subtract the electromagnetic force F from the force F1. 电 The frictional force F is obtained. 摩 ;

[0015] S2: Using an electromagnet to reset the valve core, room temperature, particle-free oil is introduced into the test hydraulic valve. The displacement actuator drives the valve core to move at a constant speed in the opening direction. At this time, the force value of the tension / compression sensor is F2; ​​subtract the electromagnetic force F from the force F2. 电 and frictional force F 摩 The hydrodynamic force F is obtained. 液 ;

[0016] S3: Using an electromagnet to reset the valve core, turn on the heater, and introduce high-temperature, particle-free oil into the test hydraulic valve. The displacement actuator drives the valve core to move at a constant speed in the opening direction. At this time, the force value of the tension / compression sensor is F3; subtract the electromagnetic force F from the force F3. 电 Hydraulic F 液 and frictional force F 摩 The thermal hysteresis force F is obtained. 滞-热 ;

[0017] S4: Repeat step S3 to obtain the thermal kinetic force F at several different temperatures T. 滞-温 The data allows us to obtain the rate of change of thermal kinetic force with temperature, K = ΔF.滞-热 / ΔT;

[0018] S5: Replace the valve core in the valve body cavity, change the fit clearance width δ between the valve body and the valve core, and repeat steps S1 to S4 to obtain several sets of thermal sticking force change rates with temperature under different fit clearance widths.

[0019] S6: Based on the results obtained in step S5, the following formula is obtained through fitting.

[0020]

[0021] In the formula, a0 and b0 are both fitted coefficients, and δ0 is the fit clearance width when the thermal kinetic force is zero.

[0022] S7: For any known initial fit clearance width δ of the valve body and valve core T0 For the test hydraulic valve, based on the temperature of the incoming oil, the fitting formula obtained in step S6 is used to obtain the current fit clearance width δ between the valve body and the valve core. T δ T0 and δ T The difference is the thermal deformation of the fit clearance between the valve body and the valve core.

[0023] Preferably, in step S5, the fit clearance width between the valve body and different valve cores increases at equal intervals.

[0024] Furthermore, the equidistant increasing interval is 1 μm.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The measuring device designed in this invention can measure the valve core jamming force under the combined effects of multiple factors, thereby improving the jamming force measurement efficiency and reducing the manufacturing cost of the device. At the same time, by using the curve of the relationship between the rate of change of jamming force with temperature and the clearance, the thermal deformation of the mating clearance can be obtained indirectly and conveniently, providing a strong reference for the design of the mating clearance between the hydraulic valve body and the valve core. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the measuring device structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the hydraulic valve structure for testing the present invention;

[0029] Figure 3 This is a graph showing the rate of change of the locking force with temperature versus the clearance.

[0030] In the diagram: 1. Oil tank; 2. Suction pump; 3. Relief valve; 4. Safety valve; 5. First check valve; 6. First filter; 7. Directional control valve; 8. Heater; 9. Second check valve; 10. Flow meter; 11. Pressure gauge; 12. Thermometer; 13. Displacement actuator; 14. Test hydraulic valve; 15. Data acquisition system; 16. Condenser; 17. Second filter; 141. Valve body; 142. Electromagnet; 143. Valve core; 144. Fixing component; 145. Traction rope. Detailed Implementation

[0031] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0032] like Figure 1 As shown, this invention provides a hydraulic valve core jamming force measuring device, which mainly includes an oil tank 1 and a test hydraulic valve 14. The oil tank 1 holds a target oil fluid free of particles. The oil tank 1 is connected to the inlet of the test hydraulic valve 14 via an inlet pipe, supplying oil to the test hydraulic valve 14. A heater 8 is installed on the inlet pipe to regulate the temperature of the oil entering the test hydraulic valve 14, controlling the oil temperature in the inlet circuit and setting a thermal deformation jamming fault for the test hydraulic valve 14. The outlet of the test hydraulic valve 14 is connected to the oil tank 1 via an outlet pipe, allowing the tested oil to flow back to the oil tank 1 for reuse. A condenser 16 and a second filter 17 are installed on the outlet pipe. The condenser 16 cools the high-temperature oil in the outlet pipe, and the second filter 17 filters impurities in the oil, ensuring that the oil entering the test hydraulic valve 14 is nearly particle-free, thereby reducing measurement errors.

[0033] In this embodiment, along the oil flow direction, the oil inlet pipeline is sequentially equipped with a suction pump 2, a first check valve 5, a first filter 6, a reversing valve 7, a heater 8, a second check valve 9, a flow meter 10, a pressure gauge 11, and a thermometer 12. The oil inlet pipeline between the suction pump 2 and the first check valve 5 is also connected to the oil tank 1 via two separate pipelines equipped with an overflow valve 3 and a safety valve 4, respectively, for protection. The oil outlet pipeline is connected to the oil tank 1 after passing through the reversing valve 7.

[0034] like Figure 2As shown, the test hydraulic valve 14 mainly includes a valve body 141, a valve core 143, an electromagnet 142, and a displacement actuator 13. The valve body 141 contains a valve core 143 for controlling the opening degree. One end of the valve core 143 is made of ferromagnetic material, and an electromagnet 142 is provided on its outer side for resetting it. The other end of the valve core 143 is provided with a fixing member 144, which is externally connected to the displacement actuator 13 via a traction rope 145. The displacement actuator 13 can drive the valve core to move in the opening direction. A tension / compression sensor is provided on the displacement actuator 13 for measuring the tension force.

[0035] In this embodiment, the fixing member 144 can be a lifting eye screw, one end of which is fixed to the end of the valve core 143, and the other end is connected to a traction rope 145, which can be a steel wire rope. Both the displacement actuator 13 and the tension / compression sensor can be connected to the data acquisition system 15 to facilitate remote control and real-time data recording. A linear displacement sensor is provided on the electromagnet 142, which is used to measure the opening degree of the valve core 143; the linear displacement sensor can be an LVDT. Both the electromagnet 142 and the displacement actuator 13 are preferably located outside the valve body 141 of the test hydraulic valve 14 for easy operation.

[0036] The method for measuring the gap thermal deformation using the aforementioned hydraulic valve core sticking force measuring device is as follows:

[0037] S1: Before starting the measurement, first determine the electromagnetic force F of electromagnet 142. 电 The electromagnetic force F 电 The pressure remained constant during the test. Then, with no oil flowing into the test hydraulic valve 14, the valve core 143 was given a certain moving speed through the displacement actuator 13, causing the valve core 143 to move at a constant speed in the opening direction. The force value F1 of the tension / compression sensor was recorded at this time. The electromagnetic force F was then subtracted from the force F1. 电 The frictional force F between the valve core and the valve body is obtained. 摩 .

[0038] S2: Using electromagnet 142 to reset valve core 143, introduce room temperature, particle-free oil into the test hydraulic valve 14. The displacement actuator 13 applies a certain moving speed to valve core 143, causing it to move uniformly in the opening direction. Record the force value F2 of the tension / compression sensor at this time. Subtract the electromagnetic force F from force F2. 电 and frictional force F 摩 The hydrodynamic force F is obtained. 液 .

[0039] S3: Using electromagnet 142 to reset valve core 143, heater 8 is turned on to heat the oil to a certain temperature. High-temperature, particle-free oil is introduced into the test hydraulic valve 14. Displacement actuator 13 provides valve core 143 with a certain moving speed, causing valve core 143 to move at a constant speed in the opening direction. The force value F3 of the tension / compression sensor is recorded at this time. The electromagnetic force F is then subtracted from force F3. 电 Hydraulic F 液 and frictional force F 摩 The thermal hysteresis force F is obtained. 滞-热 .

[0040] It should be noted that the speed of the valve core 143 moving at a constant speed does not need to be consistent in steps S1 to S3 above.

[0041] S4: Repeat step S3 to obtain several sets of thermal kinetic forces F at different temperatures T. 滞-温 The data allows us to obtain the rate of change of thermal kinetic force with temperature, K = ΔF. 滞-热 / ΔT. K is the rate at which the sticking force increases with increasing temperature, representing the increase in thermal sticking force for every 1°C increase in temperature.

[0042] The different temperatures in this step do not need to be set at the same gradient.

[0043] S5: Replace the valve core 143 in the inner cavity of the valve body 141, change the fit clearance width δ between the valve body 141 and the valve core 143, and repeat steps S1 to S4 to obtain several sets of thermal sticking force change rates with temperature under different fit clearance widths.

[0044] In this embodiment, the fit clearance width between the valve body 141 and different valve cores 143 should increase at equal intervals, and the interval is preferably set to 1μm.

[0045] S6: Based on the results obtained in step S5, plot a scatter plot, and then fit the following formula.

[0046]

[0047] In the formula, a0 and b0 are both fitted coefficients, and δ0 is the fit clearance width when the thermostatic force is zero. Then, a curve of the fit clearance versus thermostatic force is plotted based on the obtained fitted formula, as shown below. Figure 3 As shown.

[0048] S7: In actual measurement, for any known initial fit clearance width δ of valve body 141 and valve core 143 T0 For the test hydraulic valve 14, based on the temperature of the incoming oil, the fitting formula obtained in step S6 is used to obtain the current fit clearance width δ between the valve body 141 and the valve core 143. T By calculating δ T0 and δT The difference is the thermal deformation of the fitting clearance between valve body 141 and valve core 143.

[0049] In other words, this invention establishes a fitting formula for the rate of change of the locking force with temperature and the gap by measuring the thermal locking force at different temperatures and gaps. This formula allows the determination of the thermal deformation of the mating gap at a given temperature. This invention can measure the valve core locking force under multiple factors and their coupling effects. Furthermore, by using the curve showing the relationship between the rate of change of the locking force with temperature and the gap, the thermal deformation of the mating gap can be obtained indirectly and conveniently.

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.

Claims

1. A hydraulic valve core sticking force measuring device, characterized in that, It includes an oil tank (1) and a test hydraulic valve (14); the oil tank (1) is connected to the inlet of the test hydraulic valve (14) through an oil inlet pipe equipped with a heater (8), and the outlet of the test hydraulic valve (14) is connected to the oil tank (1) through an oil outlet pipe equipped with a condenser (16) and a second filter (17); one end of the valve core (143) of the test hydraulic valve (14) is made of ferromagnetic material, and an electromagnet (142) is provided on the outside for resetting it. The other end of the valve core (143) is equipped with a fixing member (144), and the fixing member (144) is connected to a displacement actuator (13) that can open the valve core (143) through a traction rope (145). The displacement actuator (13) is equipped with a tension and compression sensor for measuring the magnitude of the tension.

2. The hydraulic valve core sticking force measuring device according to claim 1, characterized in that, The fixing component (144) is a lifting eye bolt, and the traction rope (145) is a steel wire rope.

3. The hydraulic valve core sticking force measuring device according to claim 1, characterized in that, The displacement actuator (13) and the tension / compression sensor are both connected to the data acquisition system (15).

4. The hydraulic valve core sticking force measuring device according to claim 1, characterized in that, The electromagnet (142) is equipped with a linear displacement sensor for measuring the opening degree of the valve core (143).

5. The hydraulic valve core sticking force measuring device according to claim 1, characterized in that, Along the direction of oil flow, the oil inlet pipeline is sequentially equipped with a suction pump (2), a first check valve (5), a first filter (6), a reversing valve (7), a heater (8), a second check valve (9), a flow meter (10), a pressure gauge (11), and a thermometer (12); the oil outlet pipeline is connected to the oil tank (1) after passing through the reversing valve (7).

6. The hydraulic valve core sticking force measuring device according to claim 5, characterized in that, The oil inlet pipeline between the suction pump (2) and the first check valve (5) is also connected to the oil tank (1) through two pipelines equipped with an overflow valve (3) and a safety valve (4).

7. The hydraulic valve core sticking force measuring device according to claim 1, characterized in that, The electromagnet (142) and the displacement actuator (13) are both located outside the valve body (141) of the test hydraulic valve (14).

8. A method for measuring the gap thermal deformation using the hydraulic valve core sticking force measuring device according to any one of claims 1 to 7, characterized in that, Specifically as follows: S1: Before the measurement begins, determine the electromagnetic force F of the electromagnet (142). 电 Subsequently, with no oil flowing into the test hydraulic valve (14), the valve core (143) is driven by the displacement actuator (13) to move at a constant speed in the opening direction. At this time, the force value of the tension / compression sensor is F1. Subtract the electromagnetic force F from the force F1. 电 The frictional force F is obtained. 摩 ; S2: Using an electromagnet (142) to reset the valve core (143), introduce room temperature, particle-free oil into the test hydraulic valve (14), and drive the valve core (143) to move at a constant speed in the opening direction through the displacement actuator (13). At this time, the force value of the tension / compression sensor is F2; ​​subtract the electromagnetic force F from the force F2. 电 and frictional force F 摩 The hydrodynamic force F is obtained. 液 ; S3: Use electromagnet (142) to reset valve core (143), turn on heater (8), and introduce high-temperature, particle-free oil into test hydraulic valve (14). The displacement actuator (13) drives valve core (143) to move at a constant speed in the opening direction. At this time, the force value of tension and compression sensor is F3; subtract electromagnetic force F from force F3. 电 Hydraulic F 液 and frictional force F 摩 The thermal hysteresis force F is obtained. 滞-热 ; S4: Repeat step S3 to obtain the thermal kinetic force F at several different temperatures T. 滞-温 The data allows us to obtain the rate of change of thermal kinetic force with temperature, K = ΔF. 滞-热 / ΔT; S5: Replace the valve core (143) in the inner cavity of the valve body (141), change the fit clearance width δ between the valve body (141) and the valve core (143), repeat steps S1 to S4, and obtain several sets of thermal retardation force change rate with temperature under different fit clearance widths. S6: Based on the results obtained in step S5, the following formula is obtained through fitting. In the formula, a0 and b0 are both fitted coefficients, and δ0 is the fit clearance width when the thermal kinetic force is zero. S7: For any known initial fit clearance width δ of valve body (141) and valve core (143) T0 The test hydraulic valve (14) is used to determine the current fit clearance width δ between the valve body (141) and the valve core (143) based on the temperature of the incoming oil and the fitting formula obtained in step S6. T δ T0 and δ T The difference is the thermal deformation of the fit clearance between the valve body (141) and the valve core (143).

9. The method for measuring gap thermal deformation according to claim 8, characterized in that, In step S5, the fit clearance width between the valve body (141) and different valve cores (143) increases at equal intervals.

10. The method for measuring gap thermal deformation according to claim 9, characterized in that, The equidistant increments are 1 μm.

Images