A sensor

Abstract

The present invention discloses a sensor, comprising a sensor probe, a connecting cable and an electrical connector. The sensor probe comprises a sensor housing, a circuit board, a pressure cover, a pressure cap, a pressure ring and a sealing sleeve. The pressure cover, the pressure cap, the pressure ring and the sealing sleeve are all provided with a through hole for the connecting cable to pass through. The sealing sleeve, the pressure ring, the pressure cap and the pressure cover are sequentially sleeved on the outside of the connecting cable from the inside to the outside. The circuit board is installed in the inner cavity of the sensor housing. The outer surface of the first end of the pressure cover is matched with the inner wall of the top of the sensor housing. When one end of the connecting cable is connected to the circuit board in the inner cavity of the sensor housing, the pressure ring can be axially compressed by the inner wall of the second end of the pressure cover and the outer wall of the pressure cap, and the sealing sleeve can be axially compressed by the pressure ring, thereby clamping the connecting cable to achieve a waterproof and dustproof effect. Compared with the prior art, the sensor connecting cable can be clamped to achieve a waterproof and dustproof effect, and the structure of the sensor can be easily miniaturized.

Description

Technical Field

[0001] The present invention relates to the technical field of monitoring equipment, and in particular to a sensor. Background Art

[0002] Sensors widely used in machinery, ships, rail transit, and other fields contain circuit boards containing sensitive devices that detect physical quantities at the measured location. These circuit boards typically transmit signals to the outside world via connecting wires or cables. To secure and protect these wires or cables, a cable lock is typically installed at the rear of the sensor to ensure waterproof and dustproof performance.

[0003] In the prior art, sensors' connecting cables are typically secured with commercially available cable glands. Consequently, the sensor's structural design must incorporate the cable gland's installation method, which results in a larger sensor design and hinders miniaturization. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a sensor that can clamp the sensor connection cable to make it waterproof and dustproof, and at the same time can make the structure of the sensor easy to miniaturize.

[0005] The sensor provided by the present invention includes a sensor probe, a connecting cable and an electrical connector;

[0006] The sensor probe includes a sensor housing, a circuit board, a pressure cover, a pressure cap, a pressure ring and a sealing sleeve; the pressure cover, the pressure cap, the pressure ring and the sealing sleeve are all provided with a through hole for the connection cable to pass through; the outside of the connection cable is sequentially sleeved with a sealing sleeve, a pressure ring, a pressure cap and a pressure cover from the inside out; the circuit board is mounted in the inner cavity of the sensor housing, the outer surface of the first end of the pressure cover is connected to the inner wall of the top of the sensor housing, the inner wall of the second end of the pressure cover is matched with the outer wall of the pressure cap to axially compress the pressure ring, and the pressure ring further axially compresses the sealing sleeve;

[0007] One end of the connecting cable is connected to the circuit board, and the other end of the connecting cable is connected to the electrical connector.

[0008] Preferably, a step plate for welding the pins of the temperature measuring element is provided at the first end of the circuit board, the thickness of the step plate is smaller than the thickness of the circuit board itself, and the first end of the pressure cover abuts against the second end of the circuit board.

[0009] Preferably, a guide groove is provided on the inner wall of the middle portion of the sensor housing, and a protrusion that cooperates with the guide groove is provided on the outer periphery of the second end of the circuit board.

[0010] Preferably, a guide groove is provided on the inner wall of the middle portion of the sensor housing, a bayonet is provided on the first end of the pressure cover, and a limiting step that cooperates with the bayonet is provided on the second end of the circuit board.

[0011] Preferably, a sensitive element and a signal conditioning circuit are mounted on the circuit board, wherein the sensitive element is used to sense the vibration and impact physical quantity of the measured position and convert it into a charge signal, and the signal conditioning circuit is used to convert the charge signal output by the sensitive element into a voltage signal and amplify it;

[0012] The signal conditioning circuit includes a first charge amplification module, a second charge amplification module and a differential amplification module;

[0013] The input end of the first charge amplification module and the input end of the second charge amplification module are respectively connected to the two ends of the sensitive element, and are used to convert the charge signal output by the sensitive element into a voltage signal;

[0014] The first input terminal and the second input terminal of the differential amplifier module are respectively connected to the output terminal of the first charge amplifier module and the output terminal of the second charge amplifier module. The output terminal of the differential amplifier module is connected to the input terminal of the post-stage detection system for differentially amplifying the voltage signals output by the first charge amplifier module and the second charge amplifier module.

[0015] Preferably, the first charge amplification module includes a first operational amplifier, a first capacitor, a first resistor, and a second resistor; and the second charge amplification module includes a second operational amplifier, a second capacitor, a third resistor, and a fourth resistor;

[0016] The inverting input terminal of the first operational amplifier serves as the input terminal of the first charge amplification module, the non-inverting input terminal of the first operational amplifier is connected to a reference voltage, the output terminal of the first operational amplifier serves as the output terminal of the first charge amplification module, the two ends of the first capacitor are respectively connected to the inverting input terminal of the first operational amplifier and the output terminal of the first operational amplifier, the first end of the first resistor is connected to the inverting input terminal of the first operational amplifier, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the output terminal of the first operational amplifier;

[0017] The inverting input terminal of the second operational amplifier serves as the input terminal of the second charge amplification module, the non-inverting input terminal of the second operational amplifier is connected to the reference voltage, the output terminal of the second operational amplifier serves as the output terminal of the second charge amplification module, the two ends of the second capacitor are respectively connected to the inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier, the first end of the third resistor is connected to the inverting input terminal of the second operational amplifier, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the output terminal of the second operational amplifier;

[0018] The differential amplifier module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a third operational amplifier;

[0019] The first end of the fifth resistor serves as the first input end of the differential amplifier module, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the inverting input end of the third operational amplifier, the second end of the sixth resistor is connected to the reference voltage, the first end of the seventh resistor serves as the second input end of the differential amplifier module, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the non-inverting input end of the third operational amplifier, the second end of the eighth resistor is connected to the output end of the third operational amplifier, and their common end serves as the output end of the differential amplifier module.

[0020] Preferably, the signal conditioning circuit further includes a bootstrap module for increasing the voltage of the voltage signals output by the first charge amplification module and the second charge amplification module;

[0021] The bootstrap module includes a ninth resistor, a tenth resistor, and a third capacitor, wherein a first end of the ninth resistor is connected to a connection node between the second end of the first resistor and the first end of the second resistor, a second end of the ninth resistor is connected to a first end of the third capacitor, a second end of the third capacitor is connected to the first end of the tenth resistor, and a second end of the tenth resistor is connected to a connection node between the second end of the third resistor and the first end of the fourth resistor;

[0022] or,

[0023] The bootstrap module includes an eleventh resistor and a fourth capacitor, the first end of the eleventh resistor is connected to the connection node between the second end of the first resistor and the first end of the second resistor, the second end of the eleventh resistor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the connection node between the second end of the third resistor and the first end of the fourth resistor.

[0024] Preferably, the signal conditioning circuit further includes an anti-interference module for enhancing the anti-interference capability of the sensitive element;

[0025] The anti-interference module includes a twelfth resistor, a thirteenth resistor, a fifth capacitor and a sixth capacitor, wherein the first end of the twelfth resistor is respectively connected to the first end of the sensitive element and the first end of the fifth capacitor, the second end of the twelfth resistor is respectively connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is respectively connected to the second end of the sensitive element and the first end of the sixth capacitor, a common end of the twelfth resistor and the thirteenth resistor is connected to the reference voltage, the second end of the fifth capacitor is connected to the input end of the first charge amplification module, and the second end of the sixth capacitor is connected to the input end of the second charge amplification module;

[0026] or,

[0027] The anti-interference module includes a fourteenth resistor, a seventh capacitor and an eighth capacitor. The first end of the fourteenth resistor is respectively connected to the first end of the sensitive element and the first end of the seventh capacitor, the second end of the fourteenth resistor is respectively connected to the second end of the sensitive element and the first end of the eighth capacitor, the second end of the seventh capacitor is connected to the input end of the first charge amplification module, and the second end of the eighth capacitor is connected to the input end of the second charge amplification module.

[0028] Preferably, the signal conditioning circuit further includes a first power processing module;

[0029] The input end of the first power processing module is connected to the input power supply, the first output end of the first power processing module is used to provide the power supply voltage, and the second output end of the first power processing module is used to provide the reference voltage.

[0030] Preferably, the signal conditioning circuit further includes a second power processing module;

[0031] The input end of the second power processing module is connected to the second output end of the first power processing module, and the output end of the second power processing module is used to supply power to the temperature measuring element.

[0032] The sensor provided by the present invention includes a sensor probe, a connecting cable and an electrical connector. The sensor probe includes a sensor housing, a circuit board, a pressure cover, a pressure cap, a pressure ring and a sealing sleeve. The pressure cover, the pressure cap, the pressure ring and the sealing sleeve are all provided with a through hole for the connecting cable to pass through. The outside of the connecting cable is sequentially covered with a sealing sleeve, a pressure ring, a pressure cap and a pressure cover from the inside to the outside. The circuit board is installed in the inner cavity of the sensor housing. The outer surface of the first end of the pressure cover is connected to the inner wall of the top of the sensor housing. When one end of the connecting cable is connected to the circuit board in the inner cavity of the sensor housing, the inner wall of the second end of the pressure cover cooperates with the outer wall of the pressure cap to axially compress the pressure ring, and the pressure ring can further axially compress the sealing sleeve, thereby clamping the connecting cable to achieve a waterproof and dustproof effect. Therefore, compared with the prior art, the sensor provided by the present invention can clamp the sensor connecting cable to achieve a waterproof and dustproof effect, and at the same time can make the structure of the sensor easy to miniaturize. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 An overall structural diagram of a sensor provided by an embodiment of the present invention;

[0035] Figure 2 A schematic structural diagram of a sensor probe provided by an embodiment of the present invention;

[0036] Figure 3 A schematic perspective view of a sensor housing provided by an embodiment of the present invention;

[0037] Figure 4 A schematic cross-sectional view of a sensor housing provided by an embodiment of the present invention;

[0038] Figure 5 A three-dimensional schematic diagram of a circuit board provided in an embodiment of the present invention;

[0039] Figure 6 A schematic front view of a circuit board provided in an embodiment of the present invention;

[0040] Figure 7 A left side schematic diagram of a circuit board provided in an embodiment of the present invention;

[0041] Figure 8 A schematic structural diagram of a signal conditioning circuit provided by an embodiment of the present invention;

[0042] Figure 9 A schematic structural diagram of another signal conditioning circuit provided by an embodiment of the present invention;

[0043] Figure 10 A schematic structural diagram of another signal conditioning circuit provided by an embodiment of the present invention;

[0044] Figure 11 A schematic structural diagram of a first power processing module provided in an embodiment of the present invention;

[0045] Figure 12 A schematic structural diagram of a second power processing module provided in an embodiment of the present invention;

[0046] Figure 13 This is a structural diagram of another second power processing module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to enable people skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in combination with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0048] It should be noted that when an element is referred to as being “fixed on” or “set on” another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0049] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0051] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which this application can be implemented. Therefore, they have no technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0052] See also Figures 1 to 7 , an embodiment of the present invention provides a sensor, including a sensor probe, a connecting cable 7 and an electrical connector 8, the sensor probe including a sensor housing 1, a circuit board 2, a pressure cover 3, a pressure cap 4, a pressure ring 5 and a sealing sleeve 6, the pressure cover 3, the pressure cap 4, the pressure ring 5 and the sealing sleeve 6 are all provided with a through hole for the connecting cable 7 to pass through, the outside of the connecting cable 7 is sequentially sleeved with a sealing sleeve 6, a pressure ring 5, a pressure cap 4 and a pressure cover 3 from the inside to the outside, the circuit board 2 is installed in the inner cavity of the sensor housing 1, the outer surface of the first end of the pressure cover 3 is matched with the inner wall of the top of the sensor housing 1, the inner wall of the second end of the pressure cover 3 is matched with the outer wall of the pressure cap 4 to axially compress the pressure ring 5, and the pressure ring 5 then axially compresses the sealing sleeve 6, one end of the connecting cable 7 is connected to the circuit board 2, and the other end of the connecting cable 7 is connected to the electrical connector 8.

[0053] It should be noted that when the sensor is installed, one end of the sensor housing extends deep into the mounting hole of the component being measured, ensuring accurate sensing of the physical quantity at the measured location. The other end of the sensor housing is connected to a data acquisition instrument via a connecting cable and an electrical connector, transmitting the sensed physical quantity to the data acquisition instrument. In the present invention, the bottom of the sensor housing 1 refers to the end that extends deep into the mounting hole of the component being measured, and the top of the sensor housing 1 refers to the end that connects to the data acquisition instrument via a connecting cable 7 and an electrical connector 8.

[0054] In an embodiment of the present invention, a circuit board 2 is mounted within the inner cavity of a sensor housing 1. Sensitive elements on the circuit board 2 can sense the physical quantity of the measured position. A gland 3, a cap 4, a pressure ring 5, and a sealing sleeve 6 are each provided with through-holes. The sealing sleeve 6, pressure ring 5, cap 4, and gland 3 are sequentially arranged, from the inside out, over the outer side of a connecting cable 7. The connecting cable 7 can pass through the through-holes to connect to the circuit board 2 for signal transmission. The outer surface of the first end of the gland 3 engages with the inner wall of the top of the sensor housing 1 to apply axial pressure to the circuit board 2, thereby securing the circuit board 2. The inner wall of the second end of the gland 3 engages with the outer wall of the cap 4 to axially compress the pressure ring 5, which in turn compresses the sealing sleeve 6, thereby clamping the connecting cable 7 to achieve a waterproof and dustproof effect. Consequently, when designing the sensor structure, there is no need to consider externally connecting a hose or cable gland, making the sensor structure more compact. Therefore, compared to the prior art, the sensor can be clamped to achieve a waterproof and dustproof effect, while also making the sensor structure more compact.

[0055] On the basis of the above-mentioned embodiments, in some specific embodiments of the present invention, the outer periphery of the bottom of the sensor housing 1 is provided with a first outer conical surface 11 for signal transmission, the inner wall of the bottom of the sensor housing 1 is further provided with a first inner conical surface 12, and the outer periphery of the first end of the circuit board 2 is provided with a first outer conical surface 21 that cooperates with the first inner conical surface 12. In this embodiment, when the bottom of the sensor housing 1 is installed at the measured position, by providing the first outer conical surface 11, the sensing area of ​​the sensor can be increased, which is beneficial to improving the signal monitoring effect. The cooperation between the first inner conical surface 12 and the first outer conical surface 21 not only facilitates the assembly of the sensor housing 1 and the circuit board 2, but also helps the sensor housing 1 to transmit the received physical quantities such as vibration and impact signals to the sensitive elements on the circuit board 2 assembly, thereby further improving the signal monitoring sensitivity of the sensor.

[0056] Furthermore, based on the above embodiment, in a specific implementation manner, a step plate 22 for soldering the pins of the temperature measuring element is provided at the first end of the circuit board 2. The thickness of the step plate 22 is less than the thickness of the circuit board 2 itself, and the first end of the pressure cover 3 abuts against the second end of the circuit board 2. In this embodiment, a temperature measuring element generally needs to be installed inside the sensor. By providing the step plate 22 at the first end of the circuit board 2, the pins of the temperature measuring element 25 can be soldered to the step plate 22. When installing the circuit board 2, its first end is inserted into the bottom of the sensor housing 1, and the other end abuts against the first end of the pressure cover 3, thereby axially fixing the circuit board 2. At this time, since the thickness of the step plate 22 is less than the thickness of the circuit board 2 itself, after the temperature measuring element 25 is installed, the distance between its pins and the sensor housing 1 can be increased to ensure sufficient insulation distance and improve the insulation performance of the sensor.

[0057] Furthermore, based on the above embodiment, in some optional embodiments of the present invention, a guide groove 13 is provided on the inner wall of the central portion of the sensor housing 1, and a protrusion 23 is provided on the outer periphery of the second end of the circuit board 2 to cooperate with the guide groove 13. In this embodiment, the cooperation between the guide groove 13 and the protrusion 23 not only facilitates the positioning of the circuit board 2 but also improves the consistency of the sensor sensitivity.

[0058] Furthermore, based on the above embodiment, in some optional embodiments, a bayonet is provided at the first end of the gland 3, and a retaining step 24 is provided at the second end of the circuit board 2 to cooperate with the bayonet. In this embodiment, the bayonet and the retaining step 24 cooperate to radially secure the circuit board 2, thereby improving the securing effect of the circuit board 2.

[0059] As a preferred embodiment of the present invention, a protective hose is provided on the exterior of the connecting cable 7. In this embodiment, the hose has excellent flexibility and fatigue resistance, and can absorb various cyclic loads caused by motion deformation. In particular, it is capable of compensating for large displacements when measuring mechanical vibration. Therefore, the provision of the hose on the exterior of the connecting cable 7 further enhances the waterproof and dustproof properties of the connecting cable 7.

[0060] Furthermore, based on the above embodiments, in a specific implementation manner, a sensitive element 26 and a signal conditioning circuit are installed on the circuit board 2. The sensitive element 26 is used to sense the vibration impact physical quantity of the measured position and convert it into a charge signal. The signal conditioning circuit is used to convert the charge signal output by the sensitive element 26 into a voltage signal and amplify it.

[0061] In an embodiment of the present invention, the sensitive element 26 mounted on the circuit board 2 can sense the physical quantity of vibration and impact at the measured location and convert it into a charge signal. However, considering that the charge signal output by the sensor's vibration and impact sensitive element is relatively weak and easily interfered with, a signal conditioning circuit is also mounted on the circuit board 2 to convert the charge signal output by the sensitive element 26 into a voltage signal and amplify it, thereby improving the anti-interference capability of signal transmission and facilitating acquisition by the subsequent acquisition circuit. Optionally, a shielding cover is provided on the outside of the signal conditioning circuit to shield interference and further improve the stability of signal transmission.

[0062] See also Figures 8 to 13 , based on the above embodiment, in a specific implementation manner, the signal conditioning circuit includes a first charge amplification module 271, a second charge amplification module 272 and a differential amplification module 273;

[0063] The input end of the first charge amplification module 271 and the input end of the second charge amplification module 272 are respectively connected to the two ends of the sensitive element 26, and are used to convert the charge signal output by the sensitive element 26 into a voltage signal;

[0064] The first input terminal and the second input terminal of the differential amplifier module 273 are respectively connected to the output terminal of the first charge amplifier module 271 and the output terminal of the second charge amplifier module 272. The output terminal of the differential amplifier module 273 is connected to the input terminal of the subsequent detection system for differentially amplifying the voltage signals output by the first charge amplifier module 271 and the second charge amplifier module 272.

[0065] Specifically, based on the above embodiment, in some optional embodiments of the present invention, the first charge amplification module 271 includes a first operational amplifier, a first capacitor, a first resistor, and a second resistor; the second charge amplification module 272 includes a second operational amplifier, a second capacitor, a third resistor, and a fourth resistor;

[0066] The inverting input terminal of the first operational amplifier serves as the input terminal of the first charge amplification module 271, the non-inverting input terminal of the first operational amplifier is connected to the reference voltage, the output terminal of the first operational amplifier serves as the output terminal of the first charge amplification module 272, the two ends of the first capacitor are respectively connected to the inverting input terminal of the first operational amplifier and the output terminal of the first operational amplifier, the first end of the first resistor is connected to the inverting input terminal of the first operational amplifier, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the output terminal of the first operational amplifier;

[0067] The inverting input terminal of the second operational amplifier serves as the input terminal of the second charge amplification module 272, the non-inverting input terminal of the second operational amplifier is connected to the reference voltage, the output terminal of the second operational amplifier serves as the output terminal of the second charge amplification module 271, the two ends of the second capacitor are respectively connected to the inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier, the first end of the third resistor is connected to the inverting input terminal of the second operational amplifier, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the output terminal of the second operational amplifier.

[0068] In the embodiment of the present invention, the first charge amplification module 271 is composed of a first operational amplifier N1A, a first capacitor C1, a first resistor R1 and a second resistor R2, and the second charge amplification module 272 is composed of a second operational amplifier N1B, a second capacitor C2, a third resistor R3 and a fourth resistor R4. The non-inverting inputs of the first operational amplifier N1A and the second operational amplifier N1B are both connected to the reference voltage VDD. The inverting inputs of the first operational amplifier N1A and the second operational amplifier N1B are respectively connected to the two ends of the sensitive element 26. The outputs of the first operational amplifier N1A and the second operational amplifier N1B are respectively connected to the first input and the second input of the differential amplifier module 273. The first capacitor C1 and the second capacitor C2 are used to achieve charge-to-voltage conversion. The first capacitor C1 is connected between the inverting input of the first operational amplifier N1A and the output of the first operational amplifier N1A, and the second capacitor C1 is connected between the inverting input of the second operational amplifier N1B and the output of the first operational amplifier N1A. The first resistor R1 and the second resistor R2 are connected in series and in parallel across the first capacitor C1 to ensure normal static operation of the first operational amplifier N1A. The third resistor R3 and the fourth resistor R4 are connected in series and in parallel across the second capacitor C2 to ensure normal static operation of the second operational amplifier N1B.

[0069] Further, based on the above embodiments, in some optional embodiments, the differential amplifier module 273 includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a third operational amplifier; wherein, the first end of the fifth resistor serves as the first input end of the differential amplifier module 273, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the inverting input end of the third operational amplifier, the second end of the sixth resistor is connected to the reference voltage, the first end of the seventh resistor serves as the second input end of the differential amplifier module 273, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the non-inverting input end of the third operational amplifier, the second end of the eighth resistor is connected to the output end of the third operational amplifier, and their common end serves as the output end of the differential amplifier module 273.

[0070] In this embodiment of the present invention, the differential amplifier module 273 comprises two symmetrical groups of fifth and sixth resistors R5 and R6, seventh and eighth resistors R7 and R8, and a third operational amplifier N1C. The first end of the fifth resistor R5 and the first end of the seventh resistor R7 are connected to the output of the first charge amplifier module 271 and the output of the second charge amplifier module 272, respectively. The second end of the fifth resistor R5 and the second end of the seventh resistor R7 are connected to the inverting input of the third operational amplifier N1C and the non-inverting input of the third operational amplifier N1C, respectively. The first end of the sixth resistor R6 is connected to the reference voltage VDD, and the second end of the sixth resistor R6 is connected to the connection node between the second end of the fifth resistor R5 and the inverting input of the third operational amplifier N1C. The first end of the eighth resistor R8 is connected to the connection node between the second end of the seventh resistor R7 and the non-inverting input of the third operational amplifier N1C, and the second end of the eighth resistor R8 is connected to the output of the third operational amplifier N1C. The common end of the eighth resistor R8 is connected to the input of the subsequent detection system. The positive power supply terminal of the third operational amplifier N1C is connected to the power supply voltage VCC, and the ground terminal of the third operational amplifier N1C is grounded.

[0071] Furthermore, based on the above embodiment, in some optional embodiments, the signal conditioning circuit further includes a bootstrap module 274 for boosting the voltage of the voltage signal output by the first charge amplification module 271 and the second charge amplification module 272. The bootstrap module 274 includes a ninth resistor, a tenth resistor, and a third capacitor; wherein the first end of the ninth resistor is connected to a connection node between the second end of the first resistor and the first end of the second resistor, the second end of the ninth resistor is connected to the first end of the third capacitor, the second end of the third capacitor is connected to the first end of the tenth resistor, and the second end of the tenth resistor is connected to a connection node between the second end of the third resistor and the first end of the fourth resistor.

[0072] In this embodiment of the present invention, considering that the gain of the sensitive element 26 is too low in the low-frequency range, a bootstrap module 274 is designed between the first charge amplification module 271 and the second charge amplification module 272 to increase the voltage of the voltage signal output by the first charge amplification module 271 and the second charge amplification module 272. Specifically, the bootstrap module 274 is composed of a ninth resistor R9, a tenth resistor R10, and a third capacitor C3. The ninth resistor R9 and the tenth resistor R10 are both current-limiting resistors. The first end of the ninth resistor R9 is connected between the first resistor R1 and the second resistor R2, and the second end of the ninth resistor R9 is connected to one end of the third capacitor C3. The first end of the tenth resistor R10 is connected between the third resistor R3 and the fourth resistor R4, and the second end of the tenth resistor R10 is connected to the other end of the third capacitor C3. The third capacitor C3 is a bootstrap capacitor used to increase the voltage of the voltage signal output by the first charge amplification module 271 and the second charge amplification module 272 to compensate for the insufficient gain of the sensitive element 26 in the low-frequency range.

[0073] Alternatively, in another specific embodiment, the bootstrap module 274 includes an eleventh resistor and a fourth capacitor; wherein the first end of the eleventh resistor is connected to the connection node between the second end of the first resistor and the first end of the second resistor, the second end of the eleventh resistor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the connection node between the second end of the third resistor and the first end of the fourth resistor. In this embodiment, the bootstrap module 274 is composed of the eleventh resistor R11 and the fourth capacitor C4.

[0074] As a preferred embodiment of the present invention, the signal conditioning circuit also includes an anti-interference module 275 for improving the anti-interference capability of the sensitive element 26; the anti-interference module 275 includes a twelfth resistor, a thirteenth resistor, a fifth capacitor and a sixth capacitor, wherein the first end of the twelfth resistor is respectively connected to the first end of the sensitive element 26 and the first end of the fifth capacitor, the second end of the twelfth resistor is connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is respectively connected to the second end of the sensitive element 26 and the first end of the sixth capacitor, the common end of the twelfth resistor and the thirteenth resistor is connected to the reference voltage, the second end of the fifth capacitor is connected to the input end of the first charge amplification module 271, and the second end of the sixth capacitor is connected to the input end of the second charge amplification module 272.

[0075] Specifically, the anti-interference module 275 is composed of an eleventh resistor R11, a fourth capacitor C4 and a fifth capacitor C5, wherein the eleventh resistor R11 is connected at both ends of the sensitive element 26, the fourth capacitor C4 is connected in series between the first end of the sensitive element 26 and the input end of the first charge amplification module 271, and the fifth capacitor C5 is connected in series between the second end of the sensitive element 26 and the input end of the second charge amplification module 272, which can effectively improve the anti-interference ability of the sensitive element 26.

[0076] Alternatively, in another specific embodiment, the anti-interference module 275 includes a fourteenth resistor, a seventh capacitor, and an eighth capacitor, wherein the first end of the fourteenth resistor is respectively connected to the first end of the sensitive element 26 and the first end of the seventh capacitor, the second end of the fourteenth resistor is respectively connected to the second end of the sensitive element 26 and the first end of the eighth capacitor, the second end of the seventh capacitor is connected to the input end of the first charge amplification module 271, and the second end of the eighth capacitor is connected to the input end of the second charge amplification module 272. In this embodiment, the anti-interference module 275 is composed of the fourteenth resistor R14, the seventh capacitor C7, and the eighth capacitor C8.

[0077] As a preferred embodiment of the present invention, the signal conditioning circuit also includes a first power processing module 276; the input end of the first power processing module 276 is connected to the input power supply, the first output end of the first power processing module 276 is used to provide a power supply voltage, and the second output end of the first power processing module 276 is used to provide a reference voltage.

[0078] In an embodiment of the present invention, in order to ensure the stability of the signal conditioning circuit, a first power processing module 276 is added to the signal conditioning circuit, whose input end is connected to the external input power supply, the first output end provides a stable power supply voltage for the signal conditioning circuit, and the second output end provides a stable reference voltage for the signal conditioning circuit, thereby improving the accuracy of the reference voltage.

[0079] Specifically, in the above embodiment, the first power processing module 276 includes a diode, a fifteenth resistor, a ninth capacitor, a tenth capacitor and a first voltage-stabilizing diode; wherein, the anode of the diode serves as the input end of the first power processing module 276, the cathode of the diode is respectively connected to the first end of the fifteenth resistor and the first end of the ninth capacitor, and the common end thereof serves as the first output end of the first power processing module 276, the second end of the fifteenth resistor is respectively connected to the first end of the tenth capacitor and the cathode of the first voltage-stabilizing diode, and the common end thereof serves as the second output end of the first power processing module 276, and the second end of the ninth capacitor, the second end of the tenth capacitor and the anode of the first voltage-stabilizing diode are all connected to the ground.

[0080] In the embodiment of the present invention, the first power processing module 276 is composed of a diode V1, a fifteenth resistor R15, a ninth capacitor C9, a tenth capacitor C10 and a first voltage regulator Z1; wherein the diode V1 is an anti-reverse polarity diode, and its anode is connected to the external input power supply; the ninth capacitor C9 is a filter capacitor, and its first end is connected to the cathode of the diode V1, and its second end is connected to the ground; the connection node between the cathode of the diode V1 and the first end of the ninth capacitor C9 outputs a power supply voltage VCC, which supplies power to the positive power supply terminal of the operational amplifier in the signal conditioning circuit; the fifteenth resistor R15 is a current limiting resistor, which is used to limit the maximum current flowing through the first voltage regulator Z1, and its One end is connected to the connection node between the cathode of diode V1 and the first end of ninth capacitor C9; tenth capacitor C10 is a filter capacitor, first voltage-stabilizing diode Z1 is a voltage-stabilizing diode, the first end of tenth capacitor C10 and the cathode of first voltage-stabilizing diode Z1 are both connected to the second end of fifteenth resistor R15, and the first end of tenth capacitor C10 and the anode of first voltage-stabilizing diode Z1 are both connected to ground; the connection node between the second end of fifteenth resistor R15, the first end of tenth capacitor C10 and the cathode of first voltage-stabilizing diode Z1 outputs reference voltage VDD, which provides reference voltage for first charge amplification module 271, second charge amplification module 272, and differential amplification module 273. Optionally, sensitive element 26 can also be powered by reference voltage VDD; and when the temperature measuring element installed in the sensor outputs an analog signal, such as a platinum resistance temperature sensitive device, the temperature measuring element with analog signal output can also be directly powered by reference voltage VDD.

[0081] Furthermore, based on the above embodiments, in some optional embodiments, the signal conditioning circuit also includes a second power supply processing module 277; the input end of the second power supply processing module 277 is connected to the second output end of the first power supply processing module 276, and the output end of the second power supply processing module 277 is used to power the temperature measuring element.

[0082] In the embodiment of the present invention, considering that the temperature measuring element installed inside the sensor may output a digital signal, while the sensitive element 26 outputs an analog signal, in order to avoid mutual interference, a second power supply processing module 277 is added to the signal conditioning circuit, whose input end is connected to the second output end of the first power supply processing module 276, and whose output end powers the temperature measuring element with digital signal output.

[0083] Optionally, in a specific embodiment, the second power processing module 277 includes a sixteenth resistor, an eleventh capacitor and a second voltage-stabilizing diode; wherein the first end of the sixteenth resistor serves as the input end of the second power processing module 277, the second end of the sixteenth resistor is respectively connected to the first end of the eleventh capacitor and the cathode of the second voltage-stabilizing diode, and their common end serves as the output end of the second power processing module 277, and the second end of the eleventh capacitor and the anode of the second voltage-stabilizing diode are both connected to the ground.

[0084] In this embodiment of the present invention, the second power processing module 277 is composed of a sixteenth resistor R16, an eleventh capacitor C11, and a second voltage-stabilizing diode Z2. The sixteenth resistor R16 is a current-limiting resistor used to limit the maximum current flowing through the second voltage-stabilizing diode Z2, and its first end is connected to a reference voltage VDD. The eleventh capacitor C11 is a filter capacitor, and the second voltage-stabilizing diode Z2 is a voltage-stabilizing diode. The first end of the eleventh capacitor C11 and the cathode of the second voltage-stabilizing diode Z2 are both connected to the second end of the sixteenth resistor R16, and the first end of the eleventh capacitor C11 and the anode of the second voltage-stabilizing diode Z2 are both connected to ground. The connection node between the second end of the sixteenth resistor R16, the first end of the eleventh capacitor C11, and the cathode of the second voltage-stabilizing diode Z2 serves as the output end of the second power processing module 277, powering the temperature measuring element that outputs the digital signal. In other words, in this embodiment, the reference voltage VDD, after passing through a separate voltage-stabilizing circuit, powers the temperature measuring element that outputs the digital signal, resulting in a relatively simple circuit and low cost.

[0085] Optionally, in another specific embodiment, the second power processing module 277 includes a fourth operational amplifier, a seventeenth resistor and a twelfth capacitor; wherein, the non-inverting input terminal of the fourth operational amplifier serves as the input terminal of the second power processing module 277, the inverting input terminal of the fourth operational amplifier is respectively connected to the output terminal of the fourth operational amplifier and the first terminal of the seventeenth resistor, the second terminal of the seventeenth resistor is connected to the first terminal of the twelfth capacitor, their common terminal serves as the output terminal of the second power processing module 277, and the second terminal of the twelfth capacitor is connected to the ground.

[0086] In an embodiment of the present invention, the second power processing module 277 is composed of a fourth operational amplifier N1D, a seventeenth resistor R17, and a twelfth capacitor C12. The fourth operational amplifier N1D functions as a voltage follower, with its non-inverting input connected to a reference voltage VDD and its inverting input short-circuited to its output. The seventeenth resistor R17 is a current-limiting resistor, with its first end connected to the node connecting the inverting input and output of the fourth operational amplifier N1D. The twelfth capacitor C12 is a filter capacitor, with its first end connected to the second end of the seventeenth resistor R17 and its second end connected to ground. The node connecting the second end of the seventeenth resistor R17 and the first end of the twelfth capacitor C12 serves as the output of the second power processing module 277, powering the temperature measuring element that outputs the digital signal. In other words, in this embodiment, the reference voltage VDD, after passing through the voltage follower circuit, powers the temperature measuring element that outputs the digital signal, achieving voltage following and improving driving capability.

[0087] As a preferred embodiment of the present invention, the signal conditioning circuit also includes an electrostatic protection module for providing electrostatic protection; the electrostatic protection module includes a first electrostatic discharge tube, a second electrostatic discharge tube, a third electrostatic discharge tube and a fourth electrostatic discharge tube; wherein, the first end of the first electrostatic discharge tube is connected to the input end of the first power processing module 276, the first end of the second electrostatic discharge tube is connected to the second output end of the first power processing module 276, the first end of the third electrostatic discharge tube is connected to the output end of the differential amplifier module 273, the first end of the fourth electrostatic discharge tube is connected to the output end of the temperature measuring element, and the second end of the first electrostatic discharge tube, the second end of the second electrostatic discharge tube, the second end of the third electrostatic discharge tube and the second end of the fourth electrostatic discharge tube are all connected to the ground.

[0088] In an embodiment of the present invention, in order to improve the anti-static capability of the signal conditioning circuit, an electrostatic protection module is also designed in the signal conditioning circuit to provide electrostatic protection. Specifically, the electrostatic protection module includes a first electrostatic discharge tube ESD1, a second electrostatic discharge tube ESD2, a third electrostatic discharge tube ESD3, and a fourth electrostatic discharge tube ESD4; wherein the first end of the first electrostatic discharge tube ESD1 is connected to the input end of the first power processing module 276, the first end of the second electrostatic discharge tube ESD2 is connected to the second output end of the first power processing module 276, the first end of the third electrostatic discharge tube ESD3 is connected to the output end of the differential amplifier module 273, and the first end of the fourth electrostatic discharge tube ESD4 is connected to the output end of the temperature measuring element. The second ends of the first electrostatic discharge tube ESD1, the second electrostatic discharge tube ESD2, the third electrostatic discharge tube ESD3, and the fourth electrostatic discharge tube ESD4 are all connected to the ground, respectively providing electrostatic protection for the power input interface, the reference voltage output interface, the sensitive element output interface, and the temperature measuring element output interface. Optionally, when an encoding chip is installed inside the sensor, the first end of the second electrostatic discharge tube ESD2 can be connected to the output end of the encoding chip to provide electrostatic protection for the output interface of the encoding chip.

[0089] Optionally, a resistor R18 is connected between the input end of the first charge amplification module 271 and the first end of the sensitive element 26, and a resistor R19 is connected between the input end of the second charge amplification module 272 and the second end of the sensitive element 26, which can improve the anti-interference ability of the input signals of the first charge amplification module 271 and the second charge amplification module 272.

[0090] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sensor, characterized in that: Includes sensor probe, connecting cable and electrical connector; The sensor probe includes a sensor housing, a circuit board, a pressure cover, a pressure cap, a pressure ring and a sealing sleeve; the pressure cover, the pressure cap, the pressure ring and the sealing sleeve are all provided with a through hole for the connection cable to pass through; the outside of the connection cable is sequentially sleeved with a sealing sleeve, a pressure ring, a pressure cap and a pressure cover from the inside to the outside; the circuit board is installed in the inner cavity of the sensor housing, the outer surface of the first end of the pressure cover is matched with the inner wall of the top of the sensor housing, the inner wall of the second end of the pressure cover is matched with the outer wall of the pressure cap to axially compress the pressure ring, and the pressure ring further axially compresses the sealing sleeve, and the end wall of the second end of the pressure cover is in contact with the pressure cap; One end of the connecting cable is connected to the circuit board, and the other end of the connecting cable is connected to the electrical connector; A step plate for welding the pins of the temperature measuring element is provided at the first end of the circuit board, wherein the thickness of the step plate is less than the thickness of the circuit board itself, and the first end of the gland abuts against the second end of the circuit board; The circuit board is provided with a sensitive element and a signal conditioning circuit, wherein the sensitive element is used to sense the vibration and impact physical quantity of the measured position and convert it into a charge signal, and the signal conditioning circuit is used to convert the charge signal output by the sensitive element into a voltage signal and amplify it; The signal conditioning circuit includes a first charge amplification module, a second charge amplification module and a differential amplification module; The input end of the first charge amplification module and the input end of the second charge amplification module are respectively connected to the two ends of the sensitive element, and are used to convert the charge signal output by the sensitive element into a voltage signal; The first input terminal and the second input terminal of the differential amplifier module are respectively connected to the output terminal of the first charge amplifier module and the output terminal of the second charge amplifier module, and the output terminal of the differential amplifier module is connected to the input terminal of the post-stage detection system, so as to differentially amplify the voltage signals output by the first charge amplifier module and the second charge amplifier module; The signal conditioning circuit further includes a bootstrap module, configured to increase the voltage of the voltage signals output by the first charge amplification module and the second charge amplification module; The bootstrap module includes a ninth resistor, a tenth resistor, and a third capacitor, wherein a first end of the ninth resistor is connected to a middle equilibrium position of the operational amplifier stabilization resistor of the first charge amplification module, a second end of the ninth resistor is connected to a first end of the third capacitor, a second end of the third capacitor is connected to a first end of the tenth resistor, and a second end of the tenth resistor is connected to a middle equilibrium position of the operational amplifier stabilization resistor of the second charge amplification module; or, The bootstrap module includes an eleventh resistor and a fourth capacitor, wherein a first end of the eleventh resistor is connected to a middle balance position of the operational amplifier stabilization resistor of the first charge amplification module, a second end of the eleventh resistor is connected to a first end of the fourth capacitor, and a second end of the fourth capacitor is connected to a middle balance position of the operational amplifier stabilization resistor of the second charge amplification module.

2. The sensor according to claim 1, characterized in that A guide groove is provided on the inner wall of the middle portion of the sensor housing, and a protrusion that matches the guide groove is provided on the outer periphery of the second end of the circuit board.

3. The sensor according to claim 2, characterized in that A bayonet is provided at the first end of the pressure cover, and a limiting step matched with the bayonet is provided at the second end of the circuit board.

4. The sensor according to claim 1, characterized in that The first charge amplification module includes a first operational amplifier, a first capacitor, a first resistor, and a second resistor; the second charge amplification module includes a second operational amplifier, a second capacitor, a third resistor, and a fourth resistor; The inverting input terminal of the first operational amplifier serves as the input terminal of the first charge amplification module, the non-inverting input terminal of the first operational amplifier is connected to a reference voltage, the output terminal of the first operational amplifier serves as the output terminal of the first charge amplification module, the two ends of the first capacitor are respectively connected to the inverting input terminal of the first operational amplifier and the output terminal of the first operational amplifier, the first end of the first resistor is connected to the inverting input terminal of the first operational amplifier, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the output terminal of the first operational amplifier; The inverting input terminal of the second operational amplifier serves as the input terminal of the second charge amplification module, the non-inverting input terminal of the second operational amplifier is connected to the reference voltage, the output terminal of the second operational amplifier serves as the output terminal of the second charge amplification module, the two ends of the second capacitor are respectively connected to the inverting input terminal of the second operational amplifier and the output terminal of the second operational amplifier, the first end of the third resistor is connected to the inverting input terminal of the second operational amplifier, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the output terminal of the second operational amplifier; The differential amplifier module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a third operational amplifier; The first end of the fifth resistor serves as the first input end of the differential amplifier module, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the inverting input end of the third operational amplifier, the second end of the sixth resistor is connected to the reference voltage, the first end of the seventh resistor serves as the second input end of the differential amplifier module, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the non-inverting input end of the third operational amplifier, the second end of the eighth resistor is connected to the output end of the third operational amplifier, and their common end serves as the output end of the differential amplifier module.

5. The sensor according to claim 4, characterized in that The first end of the ninth resistor is connected to the middle balance position of the operational amplifier stabilizing resistor of the first charge amplification module. Specifically, the first end of the ninth resistor is connected to the connection node between the second end of the first resistor and the first end of the second resistor. The second end of the tenth resistor is connected to the middle balance position of the operational amplifier stabilizing resistor of the second charge amplification module. Specifically, the second end of the tenth resistor is connected to the connection node between the second end of the third resistor and the first end of the fourth resistor. or The first end of the eleventh resistor is connected to the middle equilibrium position of the operational amplifier stabilizing resistor of the first charge amplification module. Specifically, the first end of the eleventh resistor is connected to the connection node between the second end of the first resistor and the first end of the second resistor. The second end of the fourth capacitor is connected to the middle balance position of the operational amplifier stabilization resistor of the second charge amplification module, specifically: the second end of the fourth capacitor is connected to the connection node between the second end of the third resistor and the first end of the fourth resistor.

6. The sensor according to claim 5, characterized in that The signal conditioning circuit further includes an anti-interference module for enhancing the anti-interference capability of the sensitive element; The anti-interference module includes a twelfth resistor, a thirteenth resistor, a fifth capacitor and a sixth capacitor, wherein the first end of the twelfth resistor is respectively connected to the first end of the sensitive element and the first end of the fifth capacitor, the second end of the twelfth resistor is respectively connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is respectively connected to the second end of the sensitive element and the first end of the sixth capacitor, a common end of the twelfth resistor and the thirteenth resistor is connected to the reference voltage, the second end of the fifth capacitor is connected to the input end of the first charge amplification module, and the second end of the sixth capacitor is connected to the input end of the second charge amplification module; or, The anti-interference module includes a fourteenth resistor, a seventh capacitor and an eighth capacitor, the first end of the fourteenth resistor is respectively connected to the first end of the sensitive element and the first end of the seventh capacitor, the second end of the fourteenth resistor is respectively connected to the second end of the sensitive element and the first end of the eighth capacitor, the second end of the seventh capacitor is connected to the input end of the first charge amplification module, and the second end of the eighth capacitor is connected to the input end of the second charge amplification module.

7. The sensor according to claim 4, characterized in that The signal conditioning circuit further includes a first power processing module; The input end of the first power processing module is connected to the input power supply, the first output end of the first power processing module is used to provide the power supply voltage, and the second output end of the first power processing module is used to provide the reference voltage.

8. The sensor according to claim 7, characterized in that The signal conditioning circuit further includes a second power processing module; The input end of the second power processing module is connected to the second output end of the first power processing module, and the output end of the second power processing module is used to supply power to the temperature measuring element.

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