Sensor calibration device and calibration method for simulating actual operation condition

Abstract

The invention relates to the technical field of hydraulic component testing, in particular to a sensor calibration device and method for simulating the actual operation working condition, the sensor calibration device comprises a first driving mechanism, a second driving mechanism, a cylinder body, a valve plate and a sensor module, the first driving mechanism is connected with the cylinder body, the second driving mechanism is connected with the valve plate, and the sensor module is connected with the cylinder body. Oil is filled between the cylinder body and the valve plate, and the cylinder body and the valve plate are attached to form a valve pair. The sensor module is connected with the valve plate, the first driving mechanism drives the cylinder body to simulate the rotation of the hydraulic pump, and the second driving mechanism drives the valve plate to move along the axial direction of the first driving mechanism. The first driving mechanism drives the cylinder body to rotate so as to simulate the actual operation condition of the hydraulic pump, and the second driving mechanism drives the valve plate to move in the axial direction so as to simulate different oil film thicknesses, so that the sensor module calibration of the valve pair in the actual operation condition of the hydraulic pump is realized.

Description

Technical Field

[0001] This invention relates to the field of hydraulic component testing technology, and in particular to a sensor calibration device and calibration method that simulates actual operating conditions. Background Technology

[0002] The friction pairs inside a hydraulic pump are crucial for connecting the various components within the plunger pump to achieve its working tasks. The quality of the friction pair design determines the energy conversion and mechanical efficiency. Among the friction pairs in a hydraulic pump, the flow distribution pair is a very critical one. The thickness of the oil film formed within the flow distribution pair is an important factor in its characteristics.

[0003] The thickness of the distribution sub-oil film is primarily measured using sensors. Thickness measurement can be categorized into contact and non-contact methods. Contact methods utilize probes and other measuring equipment; however, their accuracy is limited due to the friction between the high-speed rotation of the pump and the probe, and their response speed and accuracy are typically low. Non-contact methods, in principle, employ techniques such as eddy current, inductance, ultrasound, and optics; their detection distance is typically the distance from the probe to the object being measured.

[0004] When using sensors to measure oil film thickness in hydraulic pumps, the sensors typically come with standard images from factory calibration. However, because the material uniformity, surface roughness, and medium of the measured object during sensor calibration differ from the actual operating conditions of the hydraulic pump's distribution pair, significant errors occur in the oil film thickness measurements during use. Therefore, it is necessary to recalibrate the purchased sensors and existing hydraulic pumps under simulated actual operating conditions. However, current technology lacks sensor calibration devices that simulate the actual operating conditions of the hydraulic pump's distribution pair, making it difficult to effectively guarantee the accuracy of the sensor measurement results. Summary of the Invention

[0005] The main objective of this invention is to provide a sensor calibration device and calibration method that simulates actual operating conditions, in order to solve the technical problem that the lack of a sensor calibration device that simulates the actual operating conditions of a hydraulic pump distribution pair makes it difficult to effectively guarantee the accuracy of sensor measurement results.

[0006] To achieve the above objectives, the present invention provides a sensor calibration device that simulates actual operating conditions, comprising a first drive mechanism, a second drive mechanism, a cylinder, a distribution plate, and a sensor module. The first drive mechanism is connected to the cylinder, and the second drive mechanism is connected to the distribution plate. Oil is filled between the cylinder and the distribution plate, and the cylinder and the distribution plate are fitted together to form a distribution pair. The sensor module is connected to the distribution plate. The first drive mechanism drives the cylinder to simulate the rotation of a hydraulic pump, and the second drive mechanism drives the distribution plate to move axially along the first drive mechanism.

[0007] Furthermore, it also includes a housing, which includes two end caps, an upper housing, and a lower housing. The upper and lower housings are detachably connected, and a simulated chamber is formed between the upper and lower housings. The cylinder, the distribution plate, and the sensor module are all disposed in the simulated chamber. The first drive mechanism extends into the housing from the first end of the housing and connects to the cylinder. The second drive mechanism extends into the housing from the second end of the housing and connects to the distribution plate. The first end and the second end are opposite to each other. The end caps are provided with through holes for the first drive mechanism or the second drive mechanism to pass through. The end caps are fixed to the first end and the second end respectively to seal the housing.

[0008] Furthermore, the first drive mechanism includes a first motor, a first bearing, a splined sleeve, and a splined shaft. The first bearing is installed inside the housing. The inner ring of the splined sleeve is connected to the splined shaft via a spline. The outer ring of the splined sleeve mates with the inner ring of the first bearing. The first motor is connected to the splined shaft. The cylinder is fixed to the end of the splined shaft via a spline.

[0009] More preferably, the first drive mechanism further includes a second bearing, a support disk, and a support ring. The support disk is installed inside the simulation chamber, and a circular hole is opened in the middle of the support disk. The spline shaft passes through the circular hole. The two sides of the first bearing abut against one side of the support disk and one side of the cylinder body, respectively. The second bearing is disposed on the other side of the cylinder body and cooperates with the simulation chamber. The two sides of the second bearing abut against the inner wall of the simulation chamber and one side of the support ring, respectively. A frustum-shaped hole is opened in the middle of the support ring, and the conical surface of the frustum-shaped hole fits against the cylinder body.

[0010] More preferably, it also includes an adjustment mechanism, which includes a gear carrier, a gear set, a support rod, and a rack. An adjustment hole is provided at the first end of the housing. The support rod extends from outside the housing into the simulation chamber through the adjustment hole. The support rod is slidably connected to the adjustment hole. One end of the support rod is fixedly connected to the support plate, and the other end of the support rod is fixedly connected to the rack. The rack meshes with the gear set, and the gear set is rotatably connected to the gear carrier.

[0011] More preferably, four support rods and four racks are provided, and the support rods and racks are arranged at equal intervals around the spline shaft. The gear set includes a first bevel gear and two second bevel gears. The two second bevel gears are arranged opposite each other and mesh with the first bevel gear respectively. The support rod includes a first support rod and a second support rod. The rack includes two fixed racks and two movable racks. One fixed rack and one movable rack mesh with the same second bevel gear. The first support rod is connected to the fixed rack, and the second support rod is connected to the movable rack. The movable rack includes a rack section, a connecting section, a rotating section, a push plate, and multiple rollers. The second support rod has a slot, and the rack section is slidably connected in the slot. The connecting section and the rotating section are both provided with conversion slots. The multiple rollers are arranged in a roller chain and disposed in the conversion slots. The two ends of the roller chain are respectively connected to the rack section and the push plate. The push plate is connected to the second support rod.

[0012] Furthermore, the second drive mechanism includes a third bearing and a lead screw shaft. The third bearing is fixed inside the housing. The outer ring of the lead screw shaft mates with the inner ring of the third bearing. The distribution plate is connected to the lead screw shaft. Rotation of the lead screw shaft causes the distribution plate to move axially along the lead screw shaft.

[0013] More preferably, the second drive mechanism further includes a first nut, a second nut, and a third nut. The first nut has a first flange, which forms a first outer surface with a large diameter and a second outer surface with a small diameter on the outer surface of the first nut. The length of the first nut is greater than the thickness of the distribution plate. The inner surface of the first nut has a first internal thread corresponding to the screw thread. The second outer surface of the first nut has a first external thread. The middle part of both sides of the distribution plate has a groove, and the first flange transitions into the groove. The inner surface of the second nut is provided with a second internal thread corresponding to the first external thread, and the outer surface of the second nut is provided with a second external thread. The second nut is connected to the first nut through the second internal thread, and the distribution plate is sandwiched between the first nut and the second nut. The inner surface of the third nut is provided with a third internal thread corresponding to the second external thread. The third nut is connected to the second nut through the third internal thread. The third nut is provided with a support plate. The inner wall of the simulation chamber is provided with a limiting groove. The depth of the limiting groove is greater than the stroke of the distribution plate. The support plate is inserted into the limiting groove to restrict the rotation of the distribution plate.

[0014] More preferably, the sensor module includes a fourth nut, a first sensor, and a second sensor. The first sensor is fixed to the distribution plate. The thread of the fourth nut is consistent with the first internal thread. The fourth nut is disposed outside the housing and meshes with the screw thread. A stop is provided in the radial direction of the fourth nut. The second sensor is opposite to the stop to measure the displacement of the fourth nut.

[0015] The present invention also provides a sensor calibration method simulating actual operating conditions, using the sensor calibration device described above, and comprising the following steps: S1. Obtain the position of the distributor plate and determine whether the shortest distance from the distributor plate to the cylinder is 0. If yes, start the first drive mechanism and proceed to step S2. If no, start the second drive mechanism to drive the distributor plate to move a preset distance toward the cylinder and repeat step S1. S2. Obtain the rotation parameters of the cylinder block and determine whether the rotation parameters of the cylinder block are consistent with the actual rotation parameters of the cylinder block in the actual operating conditions of the hydraulic pump. S3. If the rotation parameters of the cylinder are consistent with the actual rotation parameters of the cylinder in the actual operating conditions of the hydraulic pump, then maintain the rotation parameters of the cylinder, start the second drive mechanism to drive the distribution plate to move a preset distance away from the cylinder, and obtain the i-th measurement value of the sensor module; where i is the number of times the distribution plate moves, i=1, and i is a positive integer; S4. Obtain the maximum number of movements n in the calibration test, and determine whether i is less than n; if yes, then i = i + 1, and return to step S3; if no, then stop the second drive mechanism and proceed to step S5. S5. Plot the measurement value change curve based on the n measurement values ​​of the sensor module, and obtain the change curve reflecting the relationship between the measurement value and the oil film thickness based on the number of times the distribution plate moves and the preset distance, thus completing the sensor calibration process.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In this invention, the first drive mechanism drives the cylinder to rotate to simulate the actual operating conditions of the hydraulic pump, and the second drive mechanism drives the distributor plate to move axially to simulate different oil film thicknesses. This allows for the calibration of the sensor module in the distributor pair under actual hydraulic pump operating conditions, and the plotting of the relationship between the sensor module's measured values ​​and the oil film thickness. During future actual operation of the hydraulic pump, technicians can quickly find the oil film thickness corresponding to the real-time measured values ​​of the sensor module based on the plotting curve, significantly improving the convenience of oil film thickness measurement and ensuring the accuracy of the measurement results. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure in one embodiment of the present invention; Figure 2 This is a schematic diagram of the overall structure in one embodiment of the present invention; Figure 3This is a schematic diagram of the calibration mechanism in one embodiment of the present invention; Figure 4 for Figure 3 AA section view in the middle; Figure 5 for Figure 4 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the adjustment mechanism in one embodiment of the present invention; Figure 7 for Figure 6 BB section view in the middle; Figure 8 This is a cross-sectional view of a movable rack in one embodiment of the present invention.

[0019] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0020] Explanation of icon numbers: 1. Test bench; 11. Base; 12. First motor; 13. First coupling; 14. Second motor; 15. Second coupling; 16. Laser interferometer probe; 2. Calibration mechanism; 21. Upper housing; 2101. Oil inlet; 22. Lower housing; 2201. Oil outlet; 2202. Limiting groove; 23. Oil inlet cover; 24. Oil outlet cover; 25. Fixed rack; 26. Lead screw shaft; 2601. Lead screw journal; 27. Second end cover; 28. Fourth nut; 29. ​​Distribution plate; 210. Cylinder block; 211. Support ring; 212. Support plate; 213. First end cover; 214. Splined shaft; 21401. Splined journal; 215. Third bearing; 216. Second bearing; 217. First bearing; 218. 219. Fourth bearing; 220. Second nut; 221. First nut; 222. Aviation plug; 223. First sensor; 224. Y-shaped sealing ring; 225. Spline sleeve; 226. Third nut; 22501. Support plate; 3. Adjustment mechanism; 31. Gear frame base; 3101. Stepped hole; 3102. Square hole; 32. Gear frame side plate; 3201. Bearing fixing hole; 3202. Protruding plate; 33. Handle; 34. Second bevel gear; 35. First bevel gear; 36. Fifth bearing; 37. Sixth bearing; 38. Seventh bearing; 4. Movable rack; 41. Support rod; 4101. Slot; 42. Rack part; 43. Roller; 44. Conversion groove; 45. Connecting part; 46. Rotating part; 47. Push plate. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0025] Please see Figures 1 to 8 This embodiment provides a sensor calibration device that simulates actual operating conditions, including a test bench 1, a calibration mechanism 2, and an adjustment mechanism 3. The calibration mechanism 2 includes a first drive mechanism, a second drive mechanism, a cylinder 210, a distribution plate 29, and a sensor module. The first drive mechanism is connected to the cylinder 210, and the second drive mechanism is connected to the distribution plate 29. Oil is filled between the cylinder 210 and the distribution plate 29, and the cylinder 210 and the distribution plate 29 are fitted together to form a distribution pair. The sensor module is connected to the distribution plate 29. The first drive mechanism drives the cylinder 210 to simulate the rotation of a hydraulic pump, and the second drive mechanism drives the distribution plate 29 to move axially along the first drive mechanism.

[0026] In one embodiment, the system further includes a housing comprising two end caps, an upper housing 21, and a lower housing 22. The upper housing 21 and the lower housing 22 are detachably connected, and a simulated chamber is formed between the upper housing 21 and the lower housing 22. The cylinder 210, the distribution plate 29, and the sensor module are all disposed within the simulated chamber. The first drive mechanism extends into the housing from a first end and connects to the cylinder 210. The second drive mechanism extends into the housing from a second end and connects to the distribution plate 29. The first end and the second end are opposite to each other. The end caps are provided with through holes for the first drive mechanism or the second drive mechanism to pass through. The end caps are fixed to the first end and the second end respectively to seal the housing.

[0027] As a further step, the first drive mechanism includes a first motor 12, a first bearing 217, a spline sleeve 224, and a spline shaft 214. The first bearing 217 is installed inside the housing. The inner ring of the spline sleeve 224 is connected to the spline shaft 214 via a spline. The outer ring of the spline sleeve 224 mates with the inner ring of the first bearing 217. The first motor 12 is connected to the spline shaft 214. The cylinder 210 is fixed to the end of the spline shaft 214 via a spline.

[0028] In a further preferred embodiment, the first driving mechanism further includes a second bearing 216, a support disk 212, and a support ring 211. The support disk 212 is installed inside the simulation chamber, and a circular hole is opened in the middle of the support disk 212. The spline shaft 214 passes through the circular hole. The two sides of the first bearing 217 abut against one side of the support disk 212 and one side of the cylinder 210, respectively. The second bearing 216 is disposed on the other side of the cylinder 210. The second bearing 216 cooperates with the simulation chamber, and the two sides of the second bearing 216 abut against the inner wall of the simulation chamber and one side of the support ring 211, respectively. A frustum hole is opened in the middle of the support ring 211, and the conical surface of the frustum hole fits against the cylinder 210.

[0029] Specifically, in this embodiment, the inner ring of the fourth bearing 218 is interference-fitted with the spline shaft 214 and abuts against the spline journal 21401 on the spline shaft 214. The outer ring is interference-fitted with the lower housing 22. One side of the fourth bearing 218 abuts against the first end cover 213 and the other side abuts against the spline journal 21401, thereby fixing the fourth bearing 218.

[0030] More specifically, in this embodiment, the support ring 211 has a conical surface with a corresponding angle. The distribution plate 29 and the cylinder body 210 are spherically fitted according to the working mode of the distribution pair. The spline shaft 214 is connected to the cylinder body 210 via a spline. The inclined surface of the distribution pair side of the cylinder body 210 coincides with the inclined surface of the support ring 211. The inner ring of the spline sleeve 224 is spline-connected to the spline shaft 214, and the outer ring is clearance-fitted with the first bearing 217. The support plate 212 has a small hole that transitions to the support rod 41. The cylinder body 210 is axially fixed under the combined action of the support ring 211 and the support plate 212. The spline shaft 214 is driven to rotate by the motor 12 under the action of the first coupling 13, and drives the cylinder body 210 to rotate through the spline structure, thereby simulating the engagement of the hydraulic pump distribution pair under normal working conditions.

[0031] In one embodiment, an adjustment mechanism 3 is further included. The adjustment mechanism 3 includes a gear carrier, a gear set, a support rod 41, and a rack. An adjustment hole is provided at the first end of the housing. The support rod 41 extends from the outside of the housing into the simulation chamber through the adjustment hole. The support rod 41 is slidably connected to the adjustment hole. One end of the support rod 41 is fixedly connected to the support disk 212, and the other end of the support rod 41 is fixedly connected to the rack. The rack meshes with the gear set, and the gear set is rotatably connected to the gear carrier.

[0032] Specifically, the Y-shaped sealing ring 223 is installed at the adjustment hole on the upper housing 21 and the lower housing 22, and the support rod 41 extends out from the adjustment hole through the Y-shaped sealing ring 223.

[0033] As a further preferred option, such as Figure 6 and Figure 7 As shown, there are four support rods 41 and four racks. The support rods 41 and racks are arranged at equal intervals around the spline shaft 214. The gear set includes a first bevel gear 35 and two second bevel gears 34. The two second bevel gears 34 are arranged opposite each other and mesh with the first bevel gear 35 respectively. The support rod 41 includes a first support rod and a second support rod. The rack includes two fixed racks 25 and two movable racks 4. One fixed rack 25 and one movable rack 4 mesh with the same second bevel gear 34. The first support rod is connected to the fixed rack 25 and the second support rod is connected to the movable rack 4. The movable rack 4 includes a rack portion 42, a connecting portion 45, a rotating portion 46, a push plate 47, and a plurality of rollers 43. The second support rod has a slot 4101, and the rack portion 42 is slidably connected in the slot 4101. The connecting portion 45 and the rotating portion 46 are both provided with conversion slots 44. The plurality of rollers 43 are arranged in a roller chain and disposed in the conversion slots 44. The two ends of the roller chain are respectively connected to the rack portion 42 and the push plate 47. The push plate 47 is connected to the second support rod.

[0034] Specifically, in the adjusting mechanism 3, the gear carrier includes a gear carrier base 31 and a gear carrier side plate 32. The seventh bearing 38 is installed in the stepped hole 3101 of the gear carrier base 31. The outer ring of the seventh bearing 38 is interference-fitted with the stepped hole 3101 and abuts against the stepped surface. The inner ring of the seventh bearing 38 is interference-fitted with the first bevel gear 35 and abuts against its stepped surface. The inner ring of the sixth bearing 37 is interference-fitted with the first bevel gear 35. This achieves the fixation of the seventh bearing 38 and the first bevel gear 35.

[0035] In the adjustment mechanism 3, the fifth bearing 36 is installed in the bearing fixing hole 3201 of the gear carrier side plate 32. The outer ring of the fifth bearing 36 is interference-fitted with the bearing fixing hole 3201 and abuts against the stepped surface. The inner ring of the fifth bearing 36 is interference-fitted with the second bevel gear 34 and abuts against the stepped surface, thereby fixing the fifth bearing 36 and the second bevel gear 34.

[0036] In the adjusting mechanism 3, the first bevel gear 35 meshes with the second bevel gear 34. The protrusion 3202 of the gear carrier side plate 32 is inserted into the square hole 3102 of the gear carrier base 31 and fixed with screws. The gear carrier base 31 and the base 11 are connected by bolts and nuts to fix the adjusting mechanism 3.

[0037] As a further step, the second drive mechanism includes a third bearing 215 and a lead screw 26. The third bearing 215 is fixed inside the housing. The outer ring of the lead screw 26 engages with the inner ring of the third bearing 215. The distribution plate 29 is connected to the lead screw 26. Rotation of the lead screw 26 causes the distribution plate 29 to move axially along the lead screw 26.

[0038] Specifically, in calibration mechanism 2, the inner ring of the third bearing 215 is interference-fitted with the lead screw shaft 26 and abuts against the lead screw journal 2601 of the lead screw shaft 26. Its outer ring is interference-fitted with the lower housing 22. One side of the third bearing 215 abuts against the second end cover 27, and the other side abuts against the stepped surface of the lower housing 22, thereby fixing the third bearing 215.

[0039] The second end cap 27 has an interference fit with the upper housing 21 and the lower housing 22. After the inner ring groove is filled with filler, the second end cap 27 has a transition fit with the lead screw shaft 26. The first end cap 213 has an interference fit with the upper housing 21 and the lower housing 22. After the inner ring groove of the first end cap 213 is filled with filler, the first end cap 213 has a transition fit with the spline shaft 214.

[0040] After the internal parts of the calibration mechanism 2 are installed, the upper housing 21 and the lower housing 22 are connected using bolts and nuts. After the connection is completed, the second end cover 27 and the first end cover 213 are connected to the upper housing 21 and the lower housing 22 using screws to achieve overall sealing of the calibration mechanism 2. The lower housing 22 is connected to the base 11 using bolts and nuts to fix the calibration mechanism 2.

[0041] In one embodiment, the second drive mechanism further includes a first nut 220, a second nut 219, and a third nut 225. The first nut 220 is provided with a first flange, such that the outer surface of the first nut 220 forms a first outer surface with a large diameter and a second outer surface with a small diameter. The length of the first nut 220 is greater than the thickness of the distribution plate 29. The inner surface of the first nut 220 is provided with a first internal thread corresponding to the lead screw thread. The second outer surface of the first nut 220 is provided with a first external thread. The middle of both sides of the distribution plate 29 is provided with a groove, and the first flange transitions into the groove. The inner surface of the second nut 219 is provided with a second internal thread corresponding to the first external thread, and the outer surface of the second nut 219 is provided with a second external thread. The second nut 219 is connected to the first nut 220 through the second internal thread, and the distribution plate 29 is sandwiched between the first nut 220 and the second nut 219. The inner surface of the third nut 225 is provided with a third internal thread corresponding to the second external thread. The third nut 225 is connected to the second nut 219 through the third internal thread. The third nut 225 is provided with a support plate 22501. The inner wall of the simulation chamber is provided with a limiting groove 2202. The depth of the limiting groove 2202 is greater than the stroke of the distribution plate 29. The support plate 22501 is inserted into the limiting groove 2202 to restrict the rotation of the distribution plate 29.

[0042] More specifically, in calibration mechanism 2, the first nut 220 and the fourth nut 28 are connected to the lead screw shaft 26 via ball screws. The third nut 225 is threadedly connected to the second nut 219, and the support plate 22501 of the third nut 225 is inserted into the limiting groove 2202 to form a fit, thereby preventing the distribution plate 29, the first nut 220, and the second nut 219 from rotating under the viscosity of the oil, thus preventing axial displacement. Under the action of the second coupling 15, the lead screw shaft 26 is driven to rotate by the second motor 14, and through the action of the ball screw structure, it drives the first nut 220 to move axially along the lead screw shaft 26. The distribution plate 29 also moves axially after being clamped.

[0043] More preferably, the sensor module includes a fourth nut 28, a first sensor 222, and a second sensor. The first sensor 222 is fixed to the distribution plate 29. The thread of the fourth nut 28 is consistent with the first internal thread. The fourth nut 28 is disposed outside the housing and meshes with the lead screw thread. A stop is provided radially on the fourth nut 28. The second sensor is opposite to the stop to measure the displacement of the fourth nut 28. The displacement of the fourth nut 28 generated by the rotation of the lead screw is consistent with the displacement of the distribution plate 29. Therefore, the measurement of the displacement of the fourth nut 28 by the second sensor can be regarded as the measurement of the displacement of the distribution plate 29.

[0044] In this embodiment, the first sensor 222 is an eddy current micro-displacement sensor, which is mounted on the distribution plate 29, and the aviation connector 221 is mounted on the upper housing 21. The wiring required by the eddy current micro-displacement sensor is connected through the aviation connector 221.

[0045] The present invention also provides a sensor calibration method simulating actual operating conditions, using the sensor calibration device described above, and comprising the following steps: S1. Obtain the position of the distribution plate 29 and determine whether the shortest distance from the distribution plate 29 to the cylinder 210 is 0. If yes, start the first drive mechanism and proceed to step S2. If no, start the second drive mechanism to drive the distribution plate 29 to move a preset distance toward the cylinder 210 and repeat step S1. S2. Obtain the rotation parameters of the cylinder 210 and determine whether the rotation parameters of the cylinder 210 are consistent with the actual rotation parameters of the cylinder 210 in the actual operating conditions of the hydraulic pump. S3. If the rotation parameters of the cylinder 210 are consistent with the actual rotation parameters of the cylinder 210 in the actual operating conditions of the hydraulic pump, then the rotation parameters of the cylinder 210 are maintained, and the second drive mechanism is started to drive the distribution plate 29 to move a preset distance away from the cylinder 210, so as to obtain the i-th measurement value of the sensor module; where i is the number of times the distribution plate 29 moves, i=1, and i is a positive integer; S4. Obtain the maximum number of movements n in the calibration test, and determine whether i is less than n; if yes, then i = i + 1, and return to step S3; if no, then stop the second drive mechanism and proceed to step S5. S5. Plot the measurement value change curve based on the n measurement values ​​of the sensor module, and obtain the change curve reflecting the relationship between the measurement value and the oil film thickness based on the number of times the distribution plate 29 moves and the preset distance, thus completing the sensor calibration process.

[0046] Before calibration begins, oil is injected through the inlet 2101, and the inlet cap 23 is tightened after filling. The first motor 12 is started to bring the cylinder speed to the specified speed. After the initial position output voltage is measured by the eddy current micro-displacement sensor, the second motor 14 is started to drive the lead screw 26 to rotate, causing the distribution plate 29 to move axially, and the oil film thickness increases accordingly, resulting in the corresponding output voltage of the eddy current displacement sensor. The laser interferometer has high precision and high resolution, and is used as a second sensor to further determine the axial movement distance of the distribution plate 29. The laser interferometer probe 16 is mounted on the base 11, facing the fourth nut 28, and a corresponding optical path is set between the laser interferometer probe 16 and the stop of the fourth nut 28. When the lead screw 26 rotates and drives the distribution plate 29 to move axially, the fourth nut 28 moves axially synchronously. The axial movement distance of the distribution plate 29 is determined by the change in the distance between the laser interferometer probe 16 and the stop. The distribution plate 29 is continuously moved to obtain the output voltage at different displacements. A calibration image of the eddy current displacement sensor is plotted, which is a curve reflecting the relationship between the output voltage and the oil film thickness. After completion, the second motor 14 is reversed to reset the distribution plate 29. After multiple measurements and verifications, the final calibration image of the eddy current displacement sensor is obtained. After completion, the oil outlet cap 24 is unscrewed to discharge the oil from the oil outlet 2201. The upper housing 21 and lower housing 22 are opened, and the cylinder 210 and distribution plate 29 are reinstalled into the hydraulic pump.

[0047] Compared with existing technologies, this invention retains the complete distribution pair structure. The rotation of the spline shaft 214 drives the cylinder 210 to rotate, making the operating environment of the distribution pair closer to actual working conditions and improving calibration accuracy. The use of a ball screw structure enables controllable axial movement of the distribution plate 29. Adjusting the step angle of the second motor 14 can adjust the rotation angle of the second motor 14, thereby adjusting the movement distance of the distribution plate 29. A reduction gear structure can be added between the second motor 14 and the lead screw shaft 26 to further refine the rotation angle of the lead screw shaft 26 and improve the movement accuracy of the distribution plate 29. The use of the adjustment mechanism 3 improves the adaptability of this invention. The conical inclination angle of the support ring 211 is suitable for most cylinders. For cylinders with small size changes, the fourth bearing 218 can abut against the cylinder 210. If the cylinder size changes significantly, the fourth bearing 218 can be replaced to abut again. Adjustment is made using the adjustment mechanism 3 to address changes in the axial size of the cylinder. Rotating handle 33 causes the first bevel gear 35 to rotate, which in turn drives the second bevel gear 34 to rotate. The spur teeth of the second bevel gear 34 mesh with the support rod 41 and the movable rack 4. The support rod 41 moves axially under the push of the spur teeth of the second bevel gear 34. The movable rack 4 moves axially under the push of the spur teeth of the second bevel gear 34, pushing the roller 43 and the push plate 47 to move, thereby pushing the support rod 41 to move axially. The support plate 212 of the calibration mechanism 2 moves axially under the drive of the support rod 41, adjusting the axial fixed distance of the cylinder 210, thereby adapting to other models of cylinder 210. In summary, this control device has the characteristics of precise control and simple structure.

[0048] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A sensor calibration device that simulates actual operating conditions, characterized by, The first driving mechanism is connected with the cylinder, the second driving mechanism is connected with the flow distribution disc, and the cylinder and the flow distribution disc are filled with oil therebetween and are attached to each other to form a flow distribution pair.

2. The sensor calibration device of claim 1, wherein, The housing comprises two end covers, an upper housing and a lower housing, the upper housing and the lower housing are detachably connected, and an analog chamber is formed between the upper housing and the lower housing, the cylinder, the flow distribution disc and the sensor module are arranged in the analog chamber, the first driving mechanism extends into the housing interior from a first end of the housing and is connected with the cylinder, the second driving mechanism extends into the housing interior from a second end of the housing and is connected with the flow distribution disc, the first end and the second end are opposite to each other, the end cover is provided with a through hole through which the first driving mechanism or the second driving mechanism passes, and the end cover is fixed to the first end and the second end respectively to seal the housing.

3. The sensor calibration apparatus of claim 2, wherein The first driving mechanism comprises a first motor, a first bearing, a spline sleeve and a spline shaft, the first bearing is mounted in the housing, the inner ring of the spline sleeve is connected with the spline shaft through splines, the outer ring of the spline sleeve is matched with the inner ring of the first bearing, the first motor is connected with the spline shaft, and the cylinder is fixed to the end of the spline shaft through splines.

4. The sensor calibration apparatus of claim 3, wherein The first driving mechanism further comprises a second bearing, a support disc and a support ring, the support disc is mounted in the analog chamber, a circular hole is formed in the middle of the support disc, the spline shaft passes through the circular hole, the two sides of the first bearing are respectively abutted with the support disc and one side of the cylinder, the second bearing is arranged on the other side of the cylinder, the second bearing is matched with the analog chamber, the two sides of the second bearing are respectively abutted with the inner wall of the analog chamber and one side of the support ring, a circular cone hole is formed in the middle of the support ring, and the taper surface of the circular cone hole is attached to the cylinder.

5. The sensor calibration device of claim 4, wherein, The adjusting mechanism comprises a gear frame, a gear set, a support rod and a rack, an adjusting hole is formed in the first end of the housing, the support rod extends into the analog chamber from the housing through the adjusting hole, the support rod is slidably connected with the adjusting hole, one end of the support rod is fixedly connected with the support disc, the other end of the support rod is fixedly connected with the rack, the rack is engaged with the gear set, and the gear set is rotatably connected with the gear frame.

6. The sensor calibration apparatus of claim 5, wherein, The support rod and the rack are both provided with four, the support rod and the rack are arranged at equal intervals around the spline shaft, the gear set comprises a first bevel gear and two second bevel gears, the two second bevel gears are oppositely arranged and are engaged with the first bevel gear respectively, the support rod comprises a first support rod and a second support rod, the rack comprises two fixed racks and two movable racks, one fixed rack and one movable rack are oppositely engaged with the same second bevel gear, the first support rod is connected with the fixed rack, and the second support rod is connected with the movable rack. The movable rack comprises a rack part, a connecting part, a rotating part, a push plate and a plurality of rollers, the second support rod is provided with a clamping groove, the rack part is slidably connected in the clamping groove, the connecting part and the rotating part are both provided with a conversion groove, the plurality of rollers are arranged into a roller chain and arranged in the conversion groove, the two ends of the roller chain are connected with the rack part and the push plate respectively, and the push plate is connected with the second support rod.

7. The sensor calibration apparatus of claim 2, wherein The second driving mechanism comprises a third bearing and a lead screw shaft, the third bearing is fixed in the shell, the outer ring of the lead screw shaft is matched with the inner ring of the third bearing, the flow distribution disc is connected with the lead screw shaft, and the rotation of the lead screw shaft drives the flow distribution disc to move along the axial direction of the lead screw shaft.

8. The sensor calibration apparatus of claim 7, wherein, The second driving mechanism further comprises a first nut, a second nut and a third nut, the first nut is provided with a first flange, so that the outer surface of the first nut forms a first outer surface with a large diameter and a second outer surface with a small diameter, the length of the first nut is greater than the thickness of the flow distribution disc, the inner surface of the first nut is provided with a first internal thread corresponding to the thread of the lead screw, the second outer surface of the first nut is provided with a first external thread, the middle part of the two side surfaces of the flow distribution disc is provided with a groove, and the first flange is transitionally matched in the groove; The inner surface of the second nut is provided with a second internal thread corresponding to the first external thread, the outer surface of the second nut is provided with a second external thread, the second nut is connected with the first nut through the second internal thread, and the flow distribution disc is clamped between the first nut and the second nut; The inner surface of the third nut is provided with a third internal thread corresponding to the second external thread, the third nut is connected with the second nut through the third internal thread, the third nut is provided with a supporting plate, the inner wall of the simulation chamber is provided with a limiting groove, the depth of the limiting groove is greater than the stroke of the flow distribution disc, and the supporting plate is inserted into the limiting groove to limit the rotation of the flow distribution disc.

9. The sensor calibration apparatus of claim 7, wherein, The sensor module comprises a fourth nut, a first sensor and a second sensor, the first sensor is fixed to the flow distribution disc, the thread of the fourth nut is consistent with the first internal thread, the fourth nut is arranged outside the shell, the thread of the fourth nut is engaged with the lead screw, the fourth nut is radially provided with a stopper, and the second sensor is opposite to the stopper to measure the displacement of the fourth nut.

10. A method for calibrating a sensor simulating real operating conditions, using a sensor calibration device according to any one of claims 1 to 9, characterized in that The method comprises the following steps: S1, acquiring the position of the flow distribution disc, judging whether the shortest distance from the flow distribution disc to the cylinder body is 0; if yes, starting the first driving mechanism and entering step S2; if no, starting the second driving mechanism to drive the flow distribution disc to move a preset distance away from the cylinder body, and repeating step S1; S2, acquiring the rotation parameter of the cylinder body, and judging whether the rotation parameter of the cylinder body is consistent with the actual rotation parameter of the cylinder body in the actual operation condition of the hydraulic pump; S3, if the rotation parameter of the cylinder body is consistent with the actual rotation parameter of the cylinder body in the actual operation condition of the hydraulic pump, maintaining the rotation parameter of the cylinder body, starting the second driving mechanism to drive the flow distribution disc to move a preset distance away from the cylinder body, and obtaining the i th measurement value of the sensor module; wherein i is the number of movements of the flow distribution disc, i=1, and i is a positive integer. S4, acquire the maximum number of movements n of the calibration test, determine whether i is less than n; if yes, i=i+1, return to step S3; if no, stop the second driving mechanism, enter step S5; S5, draw a measurement value change curve according to the n measurement values of the sensor module, obtain a real-time change image reflecting the relationship between the measurement value and the oil film thickness according to the number of movements of the distribution disc and the preset distance, and complete the sensor calibration process.

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