A high-speed mechanical calibration device for a hall switch

Abstract

The application discloses a high-speed mechanical calibration device of a Hall switch, which comprises a motor, a driving pulley, a driven pulley, a measured reference gear, a sensor mounting seat and a processor, the output shaft of the motor is fixedly connected with the driving pulley, the measured reference gear is fixedly connected with the driven pulley through a connecting shaft, the driven pulley and the measured reference gear are coaxially arranged, the driving pulley and the driven pulley are drivingly connected through a belt, the to-be-measured sensor is fixedly arranged corresponding to the measured reference gear through the sensor mounting seat, and the processor is in data connection with the motor and the to-be-measured sensor; compared with a traditional rotating electromagnetic field measurement device, the application restores the application occasion of physical gear rotation and greatly simplifies the structure, so that the system is convenient to deploy, the cost is reduced by a geometric level, and the limit test frequency of a gear sensor detection device in the prior art can generally only reach 4 kHz; the application can reach a limit speed of 19 kHz, and greatly improves the upper limit of the detection of the sensor performance.

Description

Technical Field

[0001] This invention relates to the field of measurement and control application technology, specifically to a high-speed mechanical calibration device for a Hall switch. Background Technology

[0002] Currently, the measurement of automotive speed sensors (gear sensors / Hall switches) is usually carried out using a test platform. This test platform often uses a rotating electromagnetic field as an approximate equivalent. However, the change of the rotating electromagnetic field is closer to a sine wave, which is different from the actual gear tooth profile. Especially when testing sensors with a large duty cycle requirement, the rotating electromagnetic field cannot achieve a good detection effect.

[0003] Existing conventional gear sensor testing devices determine the performance of a sensor by setting a rotating gear within the device and using a sensor under test to sense and test the rotating gear. Generally, they can only perform medium or low-speed testing, and the upper limit of the rotating gear's speed is limited. However, for extreme performance testing of most Hall switches, taking Honeywell's SNDH-T4P family as an example, the switching frequency range has reached 15kHz (15,000 times / second). Conventional gear sensor testing devices cannot perform extreme performance testing on this type of Hall switch.

[0004] In view of the above-mentioned defects, the inventors of this invention have finally obtained this invention after a long period of research and practice. Summary of the Invention

[0005] To address the problem that existing sensor detection devices cannot meet the requirements for high duty cycles and high limiting frequencies, this invention provides a high-speed mechanical calibration device for Hall switches.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-speed mechanical calibration device for a Hall effect switch includes a motor, a driving pulley, a driven pulley, a reference gear under test, a sensor mounting base, and a processor. The output shaft of the motor is fixedly connected to the driving pulley. The reference gear under test is fixedly connected to the driven pulley via a connecting shaft. The driven pulley and the reference gear under test are coaxially arranged. The driving pulley and the driven pulley are connected by a belt drive. The sensor under test is fixedly arranged in the sensor mounting base corresponding to the reference gear under test. The processor is connected to the motor and the sensor under test for data transmission.

[0008] Preferably, the outer cover of the reference gear under test is provided with a protective cover, and the sensor mounting base is fixed on the protective cover.

[0009] Preferably, a stepping driver is arranged on the motor, and the power supply is connected with the motor through the stepping driver, and the processor is connected with the motor through the stepping driver.

[0010] Preferably, the rotation speed ratio of the driving pulley and the driven pulley is not less than 1:3, and the rotation speed of the motor is not less than 3000r / min.

[0011] Preferably, the measured reference gear includes a wheel ring, a central shaft sleeve and a reinforcing connecting rod, the wheel ring and the central shaft sleeve are coaxially arranged, the reinforcing connecting rod is radially arranged, and two ends of the reinforcing connecting rod are fixedly connected with the inner circular surface of the wheel ring and the outer circular surface of the central shaft sleeve respectively, and the central shaft sleeve is fixedly sleeved on the connecting shaft.

[0012] Preferably, a plurality of gear teeth are uniformly arranged on the outer circular surface of the wheel ring in a ring shape, the gear teeth are arranged in isosceles trapezoidal shape, a tooth groove is arranged between adjacent gear teeth, the tooth groove is arranged in isosceles trapezoidal shape in cross section, and the groove bottom width of the tooth groove is consistent with the tooth top width of the gear tooth.

[0013] Preferably, the experimental test frequency that can be met by the high-speed mechanical calibration device of the Hall switch is greater than the limit test frequency of the to-be-measured sensor, and the calculation formula of the experimental test frequency f is:

[0014]

[0015] Wherein, n is the number of teeth of the gear; Ni is the rotation speed of the motor, unit: r / min; z is the rotation speed ratio of the driving pulley and the driven pulley.

[0016] Preferably, the size of the groove bottom width of the tooth groove and the tooth top width of the gear tooth is 2mm, and the groove depth size of the tooth groove is 4mm-8mm.

[0017] Preferably, the high-speed mechanical calibration device of the Hall switch further comprises a shell, the shell is vertically arranged, the driving pulley and the driven pulley are arranged in the shell, the motor is fixedly arranged at the lower part of the shell, the shield is fixedly arranged at the upper part of the shell, and the lower end of the shell is fixedly arranged with a base.

[0018] Preferably, the high-speed mechanical calibration device of the Hall switch further comprises a reference sensor, the reference sensor is fixedly arranged corresponding to the measured reference gear through the sensor mounting seat, and the reference sensor is in data connection with the processor.

[0019] The beneficial effects of the present application compared with the prior art are: 1, the present application restores the application occasion of physical gear rotation compared with the traditional rotating electromagnetic field measurement device, and greatly simplifies the architecture, so that the system is easy to deploy, and the cost is reduced by several orders of magnitude. The limit test frequency of the gear sensor detection device in China is generally only 4kHz, and the limit speed of the present application can reach 19kHz, which greatly improves the upper limit of the performance detection of the sensor. At the same time, the vertical placement method of the present application can also be adapted to high-low temperature test boxes for other limit performance tests; 2, the present application can also set several different types of Hall switches and photoelectric switches at the same time for experimental comparison and secondary instrument / computer LabVIEW host computer connection to compare the performance of Hall switches or photoelectric switches. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural front view of the high-speed mechanical calibration device of the Hall switch;

[0021] Figure 2 is a side view of the high-speed mechanical calibration device of the Hall switch;

[0022] Figure 3 is a perspective exploded view of the high-speed mechanical calibration device of the Hall switch;

[0023] Figure 4 is a connection relationship diagram of the high-speed mechanical calibration device of the Hall switch;

[0024] Figure 5 is a structural view of the measured reference gear;

[0025] Figure 6 is a gear structure view of the measured reference gear;

[0026] Figure 7 is a perspective exploded view of the reference sensor;

[0027] Figure 8 is a circuit connection diagram of the reference sensor.

[0028] Numerical representation in the figure:

[0029] 1-motor; 2-driving pulley; 3-following pulley; 4-measured reference gear; 5-sensor mounting seat; 6-connection shaft; 7-belt; 8-shield; 9-outer shell; 10-base; 41-wheel ring; 42-center shaft sleeve; 43-strengthening connecting rod; 44-gear tooth; 45-gear slot; 51-skeleton; 52-encapsulation shell; 53-circuit board; 54-permanent magnet; 55-Hall IC. DETAILED DESCRIPTION

[0030] The above and other technical features and advantages of the present application will be described in more detail below with reference to the attached drawings.

[0031] Embodiment one

[0032] As Figures 1 to 4 shown, Figure 1 is a structure front view of the high-speed mechanical calibration device of the Hall switch; Figure 2 is a side view cross-sectional view of the high-speed mechanical calibration device of the Hall switch; Figure 3 is a three-dimensional exploded view of the high-speed mechanical calibration device of the Hall switch; Figure 4 is a connection relationship diagram of the high-speed mechanical calibration device of the Hall switch.

[0033] The high-speed mechanical calibration device of the Hall switch comprises a motor 1, a driving pulley 2, a driven pulley 3, a measured reference gear 4, a sensor mounting seat 5 and a processor, the output shaft of the motor 1 is fixedly connected with the driving pulley 2, the measured reference gear 4 is fixedly connected with the driven pulley 3 through a connecting shaft 6, the driven pulley 3 and the measured reference gear 4 are coaxially arranged, the driving pulley 2 and the driven pulley 3 are drivingly connected through a belt 7, a to-be-measured sensor is fixedly arranged corresponding to the measured reference gear 4 through the sensor mounting seat 5, and the processor is in data connection with the motor 1 and the to-be-measured sensor.

[0034] Preferably, the measured reference gear 4 is externally covered with a shroud 8, and the sensor mounting seat 5 is fixed on the shroud 8.

[0035] Preferably, a stepping driver is arranged on the motor 1, a power supply is connected with the motor 1 through the stepping driver, the rotation speed of the motor 1 is controlled through the stepping driver, the processor is connected with the motor 1 through the stepping driver, and the stepping driver is sent a control signal through the processor to control and read the output rotation speed of the motor 1.

[0036] The motor 1 and the stepping driver adopt a brushless motor and a servo thereof, the servo communicates with the processor through a serial port, and the brushless motor 1 servo and its phase measurement are integrally realized, so that the running state of the motor 1 can be read when the speed and the phase are adjusted.

[0037] Preferably, the speed ratio of the driving pulley 2 and the driven pulley 3 is not less than 1:3. In this embodiment, the driving pulley 2 is selected with 72 teeth and the driven pulley 3 has 24 teeth, so the speed ratio is fixed at 1:3. The nominal upper limit of the speed of the motor 1 is 3000 r / min. At this time, the upper limit of the speed that the driven pulley 3 can achieve is 9000 r / min, thereby ensuring that the reference gear 4 under test has a large speed to achieve sensor detection at the 19kHz limit test frequency.

[0038] like Figure 5 As shown, Figure 5 This is a structural view of the reference gear under test. Preferably, the reference gear 4 under test includes a ring 41, a central bushing 42, and a reinforcing connecting rod 43. The ring 41 and the central bushing 42 are coaxially arranged, and the reinforcing connecting rod 43 is radially arranged. Both ends of the reinforcing connecting rod 43 are fixedly connected to the inner surface of the ring 41 and the outer surface of the central bushing 42, respectively. The central bushing 42 is fixedly sleeved on the connecting shaft 6. Through the structural design of the reference gear 4 under test, while ensuring the number of teeth and tooth profile dimensions, the overall weight of the reference gear 4 under test is greatly reduced, thereby reducing the torque required to drive the reference gear 4 under test and further increasing the maximum speed that the reference gear 4 under test can achieve.

[0039] like Figure 6 As shown, Figure 6 This is a view of the gear tooth structure of the reference gear being tested; several gear teeth 44 are evenly distributed in a ring on the outer circumference of the ring 41. To ensure detection of sensors with a large duty cycle requirement, the cross-section of the gear teeth 44 is set as an isosceles trapezoid, and a tooth groove 45 is provided between adjacent gear teeth 44. The cross-section of the tooth groove 45 is set as an isosceles trapezoid, and the width of the bottom of the tooth groove 45 is the same as the width of the top of the gear teeth 44.

[0040] Since the reference gear 4 to be tested in this invention is different from the machine gear with continuous meshing line used for transmission, this gear does not have a meshing surface formed by the scanning of the meshing line, and therefore it is difficult to process with a machine tool. Therefore, the multi-piece lamination and riveting method of wire cutting is used for processing and assembly.

[0041] The number of teeth 44 of the reference gear 4 under test is obtained based on the rotational speed that the motor 1 can output and the limit test frequency to be tested.

[0042] The formula for calculating the experimental test frequency f is:

[0043]

[0044] Wherein, n is the number of teeth of the gear; Ni is the rotating speed of the motor, unit is r / min; z is the rotating speed ratio of the driving pulley and the driven pulley.

[0045] Based on the maximum rotating speed of the motor 1 and the fixed transmission ratio, by setting the appropriate number of teeth of the gear, the maximum value of the experimental test frequency f is greater than the limit test frequency to be detected, so as to complete the limit test frequency detection of the to-be-detected sensor by adjusting the rotating speed of the motor 1.

[0046] Generally, based on the rotating speed ratio 1:3, in the case that the upper limit of the rotating speed of the driven pulley 3 is 9000 r / min, the size of the groove bottom width b of the tooth groove 45 cross section and the size of the addendum width a of the gear tooth 44 cross section are both set to 2 mm, and the groove depth size c of the tooth groove 45 is set to 4 mm-8 mm, so that the sensor detection with the duty cycle of 50% and the limit test frequency of 19 kHz can be met.

[0047] In the embodiment, the processor controls and reads the rotating speed of the motor 1, and performs data processing based on the transmission ratio between the driving pulley 2 and the driven pulley 3 and the specific size parameters of the measured reference gear 4, so as to convert the reference signal waveform diagram provided by the to-be-detected sensor to the measured reference gear 4, and then compare the actual signal waveform diagram detected by the to-be-detected sensor, so as to realize the performance detection of the to-be-detected sensor.

[0048] The duty cycle is calculated by analyzing the actual signal waveform diagram, that is, (high level time of square wave) / (high level time+low level time)*100% is the duty cycle, which is used as the actual duty cycle of the gear in the graphic verification.

[0049] Preferably, the high-speed mechanical calibration device of the Hall switch is further provided with a shell 9, the shell 9 is vertically arranged, the driving pulley 2 and the driven pulley 3 are arranged in the shell 9, the motor 1 is fixedly arranged at the lower part of the shell 9, the shield 8 is fixedly arranged at the upper part of the shell 9, and the lower end of the shell 9 is fixedly provided with a base 10, so that the high-speed mechanical calibration device of the Hall switch can be vertically placed, and the shield 8 can be placed in a high-low temperature test box for other limit performance tests.

[0050] Compared with the conventional rotating electromagnetic field measurement device, the application restores the application occasion of the physical gear rotation and greatly simplifies the structure, so that the system is convenient to deploy and the cost is reduced by several orders of magnitude. At present, the limit test frequency of the gear sensor detection device in China is generally only 4 kHz, and the limit speed of 19 kHz can be reached through the structure setting of the application, so that the upper limit of the sensor performance detection is greatly improved.

[0051] Example 2

[0052] The high-speed mechanical calibration device of the Hall switch also includes a reference sensor. The reference sensor is fixedly installed in relation to the reference gear 4 under test via the sensor mounting base 5. The reference sensor is connected to the processor. The reference sensor and the sensor under test simultaneously detect the signal of the reference gear 4 under test, thereby simultaneously forming a reference signal waveform and an actual signal waveform in the processor. The performance of the sensor under test is detected by real-time comparison.

[0053] Provided that both the reference sensor and the sensor under test have orthogonal outputs, a four-channel oscilloscope can be selected for waveform observation and comparison. The distance between the detection end face of the reference sensor and the sensor under test and the tooth tip of the reference gear 4 under test is 0.5mm to 2mm.

[0054] like Figure 7 As shown, Figure 7 The above is a three-dimensional exploded view of the reference sensor. The reference sensor includes a frame 51, with the sensor mounting base 5 and the encapsulation housing 52 connected to its two ends respectively. The frame 51 is provided with a circuit board 53, a permanent magnet 54 and a Hall IC 55. The Hall IC 55 and the permanent magnet 54 are correspondingly arranged, and the Hall IC 55 and the circuit board 53 are connected.

[0055] The Hall IC55 is equipped with an A-phase Hall IC and a B-phase Hall IC, which are orthogonal dual-path. Both the A-phase Hall IC and the B-phase Hall IC are equipped with two Hall units. By reverse biasing the magnet, the magnetic field lines of ferromagnetic materials (such as gears) can be sensed at different points. The two differential internal analog voltages generated are pre-processed inside the Hall IC55 to facilitate accurate acquisition by subsequent devices, thereby realizing the direction determination of the measured reference gear 4.

[0056] like Figure 8 As shown, Figure 8 The circuit connection diagram of the reference sensor is shown below; the Hall IC55 includes a cross-shaped Hall element, the output of which is connected to two operational amplifiers, and each operational amplifier is connected to a filter and a Schmitt trigger in sequence. The output of the Schmitt trigger is connected to the drive gate circuit of the circuit board 53.

[0057] Preferably, the geometric centers of the two Hall units, Phase A Hall IC and Phase B Hall IC, are 1 mm apart (50 ± 10% × 2 mm = 0.8 to 1.2 mm), which is beneficial for the internal circuit to evaluate the direction of motion and update the direction output at each edge (rising and falling) of the counting signal.

[0058] Each independent channel in the reference sensor detects the permanent magnet 54 structure and motion position by measuring the magnetic field intensity. The magnetic flux formed by the measured magnetic target for motion and position change (the geometric size determines the order of A and B channel output), is measured by two Hall cells in each channel. This special design is understood in the sense of timing, which makes the IC have excellent anti-interference ability to radial vibration in the working air gap range. By detecting the common mode signal, the system steady magnetic field and system imbalance are eliminated using different frequency band parameters of the chip filter link, which separates the unwanted imbalance signal from the magnetic field voltage in the frequency domain. The subsequent demodulation restores the magnetic field voltage to the baseband, while the DC imbalance is modulated into a high-frequency signal. The magnetic field voltage can pass through the subsequent low-pass filter, while the modulated imbalance voltage is suppressed, making it have strong anti-interference ability.

[0059] The above only describes the preferred embodiments of the present application, which is only illustrative but not limiting. Those skilled in the art understand that many changes, modifications, and even equivalents can be made to the present application within the spirit and scope of the claims of the present application, but all will fall within the protection scope of the present application.

Claims

1. A high-speed mechanical calibration device for a Hall switch, characterized in that, The device includes a motor, a driving pulley, a driven pulley, a reference gear under test, a sensor mounting base, and a processor. The output shaft of the motor is fixedly connected to the driving pulley. The reference gear under test is fixedly connected to the driven pulley via a connecting shaft. The driven pulley and the reference gear under test are coaxially arranged. The driving pulley and the driven pulley are connected by a belt drive. The sensor under test is fixedly arranged in the sensor mounting base corresponding to the reference gear under test. The processor is connected to the motor and the sensor under test for data transmission. The reference gear under test includes a ring, on the outer circumference of which a plurality of teeth are evenly distributed in a ring. The teeth are configured as isosceles trapezoids, and a tooth groove is provided between adjacent teeth. The cross-section of the tooth groove is configured as an isosceles trapezoid, and the width of the bottom of the tooth groove is the same as the width of the top of the tooth. It also includes a reference sensor, which is fixedly mounted on the sensor mounting base corresponding to the reference gear under test, and the reference sensor is data connected to the processor. When the maximum speed of the driven pulley is 9000 r / min, the dimensions of the bottom width b of the tooth groove cross section and the top width a of the tooth cross section are both set to 2 mm, and the groove depth c is set to 4 mm to 8 mm, which satisfies the sensor detection with a duty cycle of 50% and a limit test frequency of 19 kHz. The high-speed mechanical calibration device of the Hall switch also includes a reference sensor. The reference sensor is fixedly set with respect to the reference gear under test through the sensor mounting base. The reference sensor is connected to the processor. The reference sensor and the sensor under test are used to detect the signal of the reference gear under test at the same time, thereby forming a reference signal waveform and an actual signal waveform in the processor at the same time. The performance of the sensor under test is detected by real-time comparison. Both the reference sensor and the sensor under test have orthogonal outputs. A four-channel oscilloscope is selected for waveform observation and comparison. The distance between the detection end face of the reference sensor and the sensor under test and the tooth tip of the reference gear under test is 0.5mm to 2mm.

2. The high-speed mechanical calibration device for a Hall switch as described in claim 1, characterized in that, The outer cover of the reference gear under test is provided with a protective cover, and the sensor mounting base is fixed on the protective cover.

3. The high-speed mechanical calibration device for a Hall switch as described in claim 1, characterized in that, The motor is equipped with a stepper driver, the power supply is connected to the motor through the stepper driver, and the processor is connected to the motor through the stepper driver.

4. The high-speed mechanical calibration device for a Hall switch as described in claim 1, characterized in that, The speed ratio of the driving pulley to the driven pulley is not less than 1:3, and the speed of the motor is not less than 3000 r / min.

5. The high-speed mechanical calibration device for a Hall switch as described in claim 4, characterized in that, The reference gear under test includes a wheel ring, a central bushing, and a reinforcing connecting rod. The wheel ring and the central bushing are coaxially arranged, the reinforcing connecting rod is radially arranged, and the two ends of the reinforcing connecting rod are respectively fixedly connected to the inner circular surface of the wheel ring and the outer circular surface of the central bushing. The central bushing is fixedly sleeved on the connecting shaft.

6. The high-speed mechanical calibration device for a Hall switch as described in claim 5, characterized in that, The high-speed mechanical calibration device of the Hall switch can meet an experimental test frequency greater than the limiting test frequency of the sensor under test. The formula for calculating the experimental test frequency f is: Where n is the number of teeth of the gear; Ni is the rotational speed of the motor in r / min; and z is the speed ratio between the driving pulley and the driven pulley.

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