A sensor

Abstract

The present invention discloses a sensor, which senses the physical quantity of the measured position through a sensitive element on a circuit board and converts it into an electrical signal. The connecting cable passes through the central opening of the compression sleeve to connect to the circuit board, and the signal is transmitted to the subsequent acquisition instrument through an electrical connector. The circuit board and the compression sleeve are both arranged in the inner cavity of the sensor housing. The first end of the circuit board is inserted into the bottom of the sensor housing. The compression sleeve can be fitted and connected with the inner wall of the sensor housing through the outer surface of the mounting portion. The circuit board can be axially pressed by the end of the fixing portion away from the mounting portion being abutted against the second end of the circuit board. The outer diameter of the fixing portion is smaller than the outer diameter of the mounting portion. That is, a gap is left between the outer surface of the fixing portion and the inner wall of the sensor housing. When the inner cavity of the sensor housing is poured with potting glue, the filling area of ​​the potting glue can be increased to increase the holding force between the compression sleeve and the inner wall of the sensor housing, thereby improving the fixing effect of the circuit board and ensuring the signal monitoring sensitivity of the sensor.

Description

Technical Field

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

[0002] As a monitoring device, sensors are widely used in machinery, ships, rail transportation and other fields. A circuit board is installed inside the sensor housing. The sensitive elements on the circuit board detect physical quantities such as vibration, impact and temperature signals at the measured position, convert them into electrical signals, and then transmit the signals through connecting cables.

[0003] Conventional technology typically inserts a circuit board into a sensor housing, secures it with pressure, and then injects potting compound into the sensor housing to achieve insulation and shockproofing. However, this method fails to accurately position the circuit board, and under prolonged vibration and impact, the circuit board can easily become loose, reducing the sensor's signal monitoring sensitivity. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a sensor that can accurately position the circuit board inside the sensor, ensure the fixing effect of the circuit board, and improve the signal monitoring sensitivity of the sensor.

[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, an inner cavity of the sensor housing is provided with a circuit board and a press sleeve, a first end of the circuit board is inserted into the bottom of the sensor housing, the press sleeve includes a press sleeve body with a central opening, the press sleeve body includes a fixing portion and a mounting portion connected to the fixing portion, the outer diameter of the fixing portion is smaller than the outer diameter of the mounting portion, an end of the fixing portion away from the mounting portion abuts against the second end of the circuit board, an outer surface of the mounting portion is in contact with the inner wall of the sensor housing, a gap is provided between the outer surface of the fixing portion and the inner wall of the sensor housing, and the inner cavity of the sensor housing is filled with potting glue;

[0007] One end of the connecting cable passes through the central opening of the pressing sleeve and is connected to the circuit board, and the other end of the connecting cable is connected to the electrical connector.

[0008] Preferably, the sensor probe also includes a pressure cover, the first end surface of the bottom end of the pressure cover abuts against the end of the mounting portion away from the fixed portion, and a sealing ring is provided between the first end surface of the bottom end of the pressure cover and the end of the mounting portion away from the fixed portion, the outer surface of the bottom end of the pressure cover is cooperatively connected with the inner wall of the sensor housing to axially compress the sealing ring, the end surface of the top end of the pressure cover is provided with an opening for the connecting cable to pass through, and the inner surface of the bottom end of the pressure cover is provided with a conical groove for installing the sealing ring.

[0009] Preferably, the sensor probe also includes a pressure cap and a sealing sleeve located inside the pressure cap, the outer sleeve of the connecting cable is provided with a hose, the inner wall of the pressure cap is connected to the outer wall of the sensor body, the pressure cap cooperates with the second end face of the bottom end of the pressure cover to axially clamp the sealing sleeve, the inner wall of the sealing sleeve and the outer surface of the top end of the pressure cover form a accommodating cavity for accommodating the hose, the inner wall of the sealing sleeve is provided with a plurality of first protrusions that cooperate with the outer wall of the hose, and the outer surface of the top end of the pressure cover is provided with a plurality of second protrusions that cooperate with the inner wall of the hose.

[0010] Preferably, a step plate for welding pins of the temperature measuring element is provided at the first end of the circuit board, and the thickness of the step plate is smaller than the thickness of the circuit board itself.

[0011] Preferably, the outer periphery of the bottom of the sensor housing is provided with a first outer conical surface for signal transmission, the inner wall of the bottom of the sensor housing is also provided with an inner conical surface, and the outer periphery of the first end of the circuit board is provided with a second outer conical surface matching the inner conical surface.

[0012] Preferably, a sensitive element and a signal conditioning circuit are installed on the side of the circuit board. The sensitive element is used to sense the vibration impact physical quantity of the measured position and convert it into a voltage signal. The signal conditioning circuit is used to convert the voltage signal output by the sensitive element into a current signal.

[0013] Preferably, the signal conditioning circuit includes an operational amplifier module, a voltage-current conversion module and an output current compensation module;

[0014] The input end of the operational amplifier module is connected to the output end of the sensitive element, and is used to adjust the level voltage signal output by the sensitive element to a preset level;

[0015] The input end of the voltage-current conversion module is connected to the output end of the operational amplifier module, and the output end of the voltage-current conversion module is connected to the input end of the post-stage detection system, for converting the voltage signal output by the operational amplifier module into a current signal;

[0016] The input end of the output current compensation module is connected to a first reference voltage, and the output end of the output current compensation module is connected to the inverting input end of the operational amplifier in the voltage-current conversion module, so as to generate a corresponding compensation current according to the first reference voltage and input the compensation current into the voltage-current conversion module to compensate for its output current signal.

[0017] Preferably, the output current compensation module includes a first resistor, a first end of the first resistor serves as an input end of the output current compensation module, and a second end of the first resistor serves as an output end of the output current compensation module.

[0018] Preferably, the voltage-current conversion module includes a second resistor, a third resistor, a fourth resistor, a first operational amplifier and an NMOS tube;

[0019] The first end of the second resistor serves as the input end of the voltage-current conversion module, the second end of the second resistor is connected to the non-inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is respectively connected to the second end of the first resistor, the first end of the third resistor and the source of the NMOS tube, the second end of the third resistor is connected to the ground, the output end of the first operational amplifier is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the gate of the NMOS tube, and the drain of the NMOS tube serves as the output end of the voltage-current conversion module.

[0020] Preferably, the operational amplifier module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a second operational amplifier;

[0021] The first end of the fifth resistor is connected to the ground, the second end of the fifth resistor is respectively connected to the non-inverting input terminal of the second operational amplifier and the first end of the sixth resistor, the second end of the sixth resistor is connected to the second reference voltage, the first end of the seventh resistor serves as the input terminal of the operational amplifier module, the second end of the seventh resistor is respectively connected to the inverting input terminal of the second operational amplifier and the first end of the eighth resistor, the second end of the eighth resistor is connected to the output terminal of the second operational amplifier, and their common end serves as the output terminal of the operational amplifier module.

[0022] The sensor provided by the present invention senses the physical quantity of the measured position through a sensitive element installed on a circuit board, and converts it into an electrical signal. The connecting cable passes through the central opening of the compression sleeve to connect to the circuit board, and the generated electrical signal is transmitted to the subsequent acquisition instrument through the electrical connector. In particular, the circuit board and the compression sleeve are both arranged in the inner cavity of the sensor housing, and the first end of the circuit board is inserted into the bottom of the sensor housing. The compression sleeve can be connected to the inner wall of the sensor housing through the outer surface of the mounting portion. The circuit board can be axially compressed by the end of the fixing portion away from the mounting portion being against the second end of the circuit board. The outer diameter of the fixing portion is smaller than the outer diameter of the mounting portion. That is, a gap is left between the outer surface of the fixing portion and the inner wall of the sensor housing. When the potting glue is poured into the inner cavity of the sensor housing, the filling area of ​​the potting glue can be increased to increase the holding force between the compression sleeve and the inner wall of the sensor housing, thereby improving the fixing effect of the circuit board. Therefore, compared with the prior art, the sensor provided by the present invention can ensure the fixing effect of the internal circuit board and improve the signal monitoring sensitivity of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 A schematic structural diagram of a sensor provided by an embodiment of the present invention;

[0025] Figure 2 A schematic structural diagram of a sensor probe provided by an embodiment of the present invention;

[0026] Figure 3 A schematic structural diagram of another sensor probe provided by an embodiment of the present invention;

[0027] Figure 4 A schematic structural diagram of a compression sleeve provided by an embodiment of the present invention;

[0028] Figure 5 A three-dimensional schematic diagram of a circuit board provided in an embodiment of the present invention;

[0029] Figure 6 A schematic front view of a circuit board provided in an embodiment of the present invention;

[0030] Figure 7 A schematic rear view of a circuit board provided in an embodiment of the present invention;

[0031] Figure 8A left side schematic diagram of a circuit board provided in an embodiment of the present invention;

[0032] Figure 9 A schematic structural diagram of a sensor housing provided by an embodiment of the present invention;

[0033] Figure 10 A schematic structural diagram of a signal conditioning circuit provided by an embodiment of the present invention;

[0034] Figure 11 A schematic structural diagram of another signal conditioning circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] As mentioned in the background technology section, sensors typically insert a circuit board into a sensor housing, secure it with pressure, and then inject potting compound into the housing to provide insulation and shockproofing. However, this fixing method cannot accurately position the circuit board, and the circuit board can easily become loose under prolonged vibration and shock, resulting in a decrease in the sensor's vibration and shock sensitivity.

[0041] In view of this, an embodiment of the present invention provides a sensor. Figures 1 to 9 The sensor includes a sensor probe 101, a connecting cable 6 and an electrical connector 102. The sensor probe 101 includes a sensor housing 1. The inner cavity of the sensor housing 1 is provided with a circuit board 2 and a pressing sleeve 3. The first end of the circuit board 2 is inserted into the bottom of the sensor housing 1. The pressing sleeve 3 includes a pressing sleeve body with a central opening. The pressing sleeve body includes a fixing portion 31 and a mounting portion 32 connected to the fixing portion 31. The outer diameter of the fixing portion 31 is smaller than the outer diameter of the mounting portion 32. The end of the fixing portion 31 away from the mounting portion 32 is against the second end of the circuit board 2. The outer surface of the mounting portion 32 is in contact with the inner wall of the sensor housing 1. A gap is provided between the outer surface of the fixing portion 31 and the inner wall of the sensor housing 1. The inner cavity of the sensor housing 1 is filled with potting glue. One end of the connecting cable 6 passes through the central opening of the pressing sleeve 3 to connect to the circuit board 2, and the other end of the connecting cable 6 is connected to the electrical connector 102.

[0042] In the embodiment of the present invention, the physical quantity of the measured position is sensed by a sensitive element mounted on the circuit board 2 and converted into an electrical signal. The connecting cable 6 is connected to the circuit board 2 through the central opening of the compression sleeve 3. The generated electrical signal is transmitted to the subsequent acquisition instrument via the electrical connector 102. The circuit board 2 and the compression sleeve 3 are both disposed within the inner cavity of the sensor housing 1, with the first end of the circuit board 2 inserted into the bottom of the sensor housing 1. The compression sleeve 3 can be in contact with the inner wall of the sensor housing 1 through the outer surface of the mounting portion 32. The end of the fixing portion 31, which is away from the mounting portion 32, abuts against the second end of the circuit board 2, thereby axially compressing the circuit board 2. The outer diameter of the fixing portion 31 is smaller than the outer diameter of the mounting portion 32. In other words, a gap is left between the outer surface of the fixing portion 31 and the inner wall of the sensor housing 1. When potting glue is poured into the inner cavity of the sensor housing 1, the filling area of ​​the potting glue can be increased, thereby increasing the holding force between the compression sleeve 3 and the inner wall of the sensor housing 1, thereby improving the fixing effect of the circuit board 2. Therefore, compared with the prior art, the sensor provided by the embodiment of the present invention can ensure the fixing effect of the internal circuit board and improve the signal monitoring sensitivity of the sensor.

[0043] In order to fix the circuit board and clamp the connecting cable of the circuit board at the same time, based on the above embodiment, in a specific embodiment, the sensor probe also includes a pressure cover 4, and the first end face of the bottom end of the pressure cover 4 is abutted against the end of the mounting portion 32 away from the fixing portion 31, and a sealing ring 5 is provided between the first end face of the bottom end of the pressure cover 4 and the end of the mounting portion 32 away from the fixing portion 31, and the outer surface of the bottom end of the pressure cover 4 is cooperated with the inner wall of the sensor housing 1 to axially compress the sealing ring 5, and the end face of the top end of the pressure cover 4 is provided with an opening for the connecting cable 6 to pass through, and the inner surface of the bottom end of the pressure cover 4 is provided with a conical groove for installing the sealing ring 5.

[0044] In this embodiment, an opening is provided on the end face of the top end of the gland 4, through which the connecting cable 6 can pass to be connected to the internal circuit board 2. A sealing ring 5 is provided between the first end face of the bottom end of the gland 4 and the end of the mounting portion 32 away from the fixing portion 31. By closely fitting the outer surface of the bottom end of the gland 4 with the inner wall of the sensor housing 1, the sealing ring 5 can be axially compressed, thereby clamping the cable 6 to achieve a waterproof and dustproof effect.

[0045] In this embodiment, the sealing ring 5 can be an O-ring. The inner surface of the bottom end of the gland 4 is provided with a tapered groove into which the O-ring can be installed. The volume of the sealing ring 5 is slightly larger than the volume of the tapered groove. During installation, the sealing ring 5 can be further compressed to axially squeeze the connecting cable 6, thereby improving the waterproof and dustproof effect.

[0046] During specific implementation, the maximum outer diameter of the mounting portion 32 can be interference fit with the inner wall of the sensor housing 1, and the outer surface of the bottom end of the pressure cover 4 can also be interference fit with the inner wall of the sensor housing 1 to ensure the reliability of the installation. At the same time, laser welding technology can also be used for welding at the joint between the pressure cover 4 and the sensor housing 1.

[0047] In order to further improve the waterproof and dustproof effect of the connecting cable, on the basis of the above embodiments, in a specific embodiment, the sensor probe also includes a pressure cap 7 and a sealing sleeve 8 located in the pressure cap 7, the outer sleeve of the connecting cable 6 is provided with a hose 9, the inner wall of the pressure cap 7 is connected with the outer wall of the sensor housing 1, the pressure cap 7 cooperates with the second end face of the bottom end of the pressure cover 4 to axially clamp the sealing sleeve 8, the inner wall of the sealing sleeve 8 and the outer surface of the top end of the pressure cover 4 form a accommodating cavity for accommodating the hose 9, the inner wall of the sealing sleeve 8 is provided with a plurality of first protrusions that cooperate with the outer wall of the hose 9, and the outer surface of the top end of the pressure cover 4 is provided with a plurality of second protrusions that cooperate with the inner wall of the hose 9.

[0048] In this embodiment, since the hose has good flexibility and fatigue resistance, it can absorb various cyclic loads of motion deformation, especially the ability to compensate for large displacements when measuring mechanical vibrations. Therefore, the hose 9 is sheathed on the outside of the connecting cable 6 to further improve the waterproof and dustproof effect of the connecting cable 6.

[0049] In this embodiment, to simultaneously clamp the external hose 9 of the connecting cable 6, the sensor probe further includes a pressing cap 7 and a sealing sleeve 8 located within the pressing cap 7. Specifically, the hose 9 can be inserted into the accommodating cavity formed by the inner wall of the sealing sleeve 8 and the outer surface of the top end of the gland 4. The pressing cap 7 cooperates with the second end surface of the bottom end of the gland 4 to axially clamp the sealing sleeve 8, thereby compressing the hose 9, thereby further improving the waterproof and dustproof effect of the connecting cable 6.

[0050] In this embodiment, to better clamp the hose and ensure waterproof and dustproof properties, the inner wall of the sealing sleeve 8 is provided with multiple first protrusions, and the outer surface of the top end of the gland 4 is provided with multiple second protrusions. Specifically, by providing multiple first protrusions on the inner wall of the sealing sleeve 8, the contact surface between the inner wall of the sealing sleeve 8 and the outer wall of the hose 9 can be increased, thereby improving the clamping force of the sealing sleeve 8 on the hose 9, increasing the friction coefficient and the degree of compression. The multiple second protrusions provided on the outer surface of the top end of the gland 4 can better fit the gland 4 to the hose 9, thereby improving the sealing effect. Optionally, the multiple first protrusions are all annular first protrusions provided along the circumference of the inner wall of the sealing sleeve 8, and the multiple second protrusions are all annular second protrusions provided along the circumference of the outer surface of the top end of the gland 4, thereby better matching the shape of the hose 9.

[0051] In a specific implementation, the inner wall of the pressure cap 7 and the outer wall of the sensor housing 1 can be interference fit, and the seam can be welded using a laser welding process. Of course, for ease of installation, the inner wall of the pressure cap 7 and the outer wall of the sensor housing 1 can also be fastened using threads. Those skilled in the art can flexibly choose according to actual needs, and no specific limitation is made here.

[0052] Optionally, based on the above embodiments, in a specific implementation, the maximum outer diameter of the bottom end of the gland 4 is greater than the minimum inner diameter of the pressure cap 7. In this embodiment, when the inner wall of the pressure cap 7 is interference-fitted with the outer wall of the sensor housing 1 or screwed together, an axial thrust can be applied to the gland 4 to ensure reliable installation of the gland 4.

[0053] In a preferred embodiment of the present invention, a stepped plate 21 is provided at the first end of the circuit board 2 for soldering the pins of a temperature measuring element. The thickness of the stepped plate 21 is less than the thickness of the circuit board 2 itself. In this embodiment, a temperature measuring element is generally installed within the sensor. By providing the stepped plate 21 at the first end of the circuit board 2, the pins of the temperature measuring element 22 can be soldered to the stepped plate 21. By designing the thickness of the stepped plate 21 to be less than the thickness of the circuit board 2 itself, the distance between the pins of the temperature measuring element 22 and the sensor housing 1 can be increased after the temperature measuring element 22 is installed, ensuring sufficient insulation distance and thus improving the insulation performance of the sensor.

[0054] As a preferred embodiment 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 also provided with an inner conical surface 12, and the first end of the circuit board 2 is provided with a second outer conical surface 23 that cooperates with the inner conical surface 12. In this embodiment, 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, thereby further improving the signal monitoring sensitivity of the sensor. A vibration impact sensitive element is installed on the circuit board 2 for detecting the vibration impact signal of the measured position. By the second outer conical surface 23 cooperating with the inner conical surface 12 provided on the inner wall of the bottom of the sensor housing 1, not only can the circuit board 2 be radially fixed, but it also helps the sensor housing 1 to transmit the vibration impact signal received at the bottom to the vibration impact sensitive element on the circuit board 2, thereby improving the signal monitoring sensitivity of the sensor.

[0055] In a preferred embodiment of the present invention, a retaining step 24 is provided at the second end of the circuit board 2. A retaining notch 311 is provided at the end of the fixing portion 31, distal from the mounting portion 32, that engages with the retaining step 24. In this embodiment, the sensor housing 1 is generally made of metal, and the compression sleeve 3 can be made of a non-metallic material to ensure that the shielded wires of the connecting cable 6 do not come into contact with the metal. The retaining step 24 and the notch 311 cooperate to radially secure the circuit board 2, further improving its securement.

[0056] As a preferred embodiment of the present invention, a groove 312 for diversion is further provided at one end of the fixing portion 31 away from the mounting portion 32, and a through-hole 321 for ventilation is provided on the end surface of the mounting portion 32. In this embodiment, when potting compound is poured into the inner cavity of the sensor housing 1, the groove 312 provided at one end of the fixing portion 31 can be used to prevent the potting compound from flowing back, thereby preventing bubbles from forming in the gap between the fixing portion 31 and the sensor housing 1. The through-hole 321 provided on the end surface of the mounting portion 32 can be used to prevent bubbles from escaping during potting compound pouring, thereby reducing the generation of bubbles.

[0057] Furthermore, based on the above embodiments, in a specific implementation manner, a sensitive element 25 and a signal conditioning circuit 26 are installed on the side of the circuit board 2. The sensitive element 25 is used to sense the vibration impact physical quantity of the measured position and convert it into a voltage signal. The signal conditioning circuit 26 is used to convert the voltage signal output by the sensitive element 25 into a current signal.

[0058] In an embodiment of the present invention, the sensitive element 25 mounted on the circuit board 2 can sense the physical quantity of vibration and impact at the measured location and convert it into a voltage signal. However, considering that the sensor sensitive element is generally powered by a low voltage, the level of the minimum output signal of the sensitive element 25 is close to zero, and the voltage analog signal output by the sensitive element 25 is susceptible to external interference during long-distance transmission. Therefore, a signal conditioning circuit 26 is also mounted on the circuit board 2 to amplify the voltage signal output by the sensitive element 25 and convert it into a current signal to improve the stability of signal transmission. Optionally, a shielding cover is provided on the outside of the signal conditioning circuit 26 to shield interference and further improve the stability of signal transmission.

[0059] See also Figure 10 and Figure 11 , based on the above embodiment, in a specific implementation manner, the signal conditioning circuit 26 includes an operational amplifier module 261, a voltage-current conversion module 262 and an output current compensation module 263;

[0060] The input end of the operational amplifier module 261 is connected to the output end of the sensitive element 25, and is used to adjust the level voltage signal output by the sensitive element 25 to a preset level;

[0061] The input end of the voltage-current conversion module 262 is connected to the output end of the operational amplifier module 261, and the output end of the voltage-current conversion module 262 is connected to the input end of the post-stage detection system, and is used to convert the voltage signal output by the operational amplifier module 261 into a current signal;

[0062] The input end of the output current compensation module 263 is connected to the first reference voltage, and the output end of the output current compensation module 263 is connected to the inverting input end of the operational amplifier in the voltage-current conversion module 262, for generating a corresponding compensation current based on the first reference voltage, and inputting it into the voltage-current conversion module 262 to compensate its output current signal.

[0063] Specifically, based on the above embodiments, in some optional embodiments, the output current compensation module 263 includes a first resistor, the first end of the first resistor serves as the input end of the output current compensation module 263, and the second end of the first resistor serves as the output end of the output current compensation module 263.

[0064] Based on the above embodiments, in a specific implementation of the present invention, the voltage-current conversion module 262 includes a second resistor, a third resistor, a fourth resistor, a first operational amplifier and an NMOS tube; the first end of the second resistor serves as the input end of the voltage-current conversion module 262, the second end of the second resistor is connected to the non-inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is respectively connected to the second end of the first resistor, the first end of the third resistor and the source of the NMOS tube, the second end of the third resistor is connected to the ground, the output end of the first operational amplifier is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the gate of the NMOS tube, and the drain of the NMOS tube serves as the output end of the voltage-current conversion module 262.

[0065] Specifically, the first resistor comprises a resistor R1 and a resistor R2 connected in parallel. The first common terminal of resistors R1 and R2 is connected to a first reference voltage VDD, and the second common terminal is connected to the inverting input of the first operational amplifier N1A. The second resistor R3 is a balancing resistor connected to the non-inverting input of the first operational amplifier N1A, used to balance the resistance of the operational amplifier input, perform impedance matching, and reduce offset current. The third resistor is a voltage-to-current conversion resistor, comprising resistors R4 and R5. The first common terminal of the resistor R5 is connected to the inverting input of the first operational amplifier N1A and the source of the NMOS transistor T1, and the second common terminal is connected to ground. The fourth resistor R6 is a current-limiting resistor. The output of the first operational amplifier N1A is connected to the gate of the NMOS transistor T1 through the fourth resistor R6, and the drain of the NMOS transistor T1 is connected to the post-stage detection system. The positive power supply terminal of the first operational amplifier N1A is connected to the power supply voltage, and the ground terminal of the first operational amplifier N1A is grounded. It should be noted that, in addition to NMOS transistors, PMOS transistors, NPN transistors, PNP transistors, and other transistors can also be selected, and the circuit structure can be modified accordingly, and the present invention is not limited thereto. In a specific implementation, considering the small output current of the sensor, the fourth resistor R6 can be selected with a smaller resistance value, and its resistance value can even be 0, which is equivalent to directly removing the fourth resistor R6 without affecting the implementation of the present technical solution.

[0066] Further, based on the above embodiments, in a specific implementation, the operational amplifier module 261 includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a second operational amplifier, the first end of the fifth resistor is connected to the ground, the second end of the fifth resistor is respectively connected to the non-inverting input terminal of the second operational amplifier and the first end of the sixth resistor, the second end of the sixth resistor is connected to the second reference voltage, the first end of the seventh resistor serves as the input terminal of the operational amplifier module 261, the second end of the seventh resistor is respectively connected to the inverting input terminal of the second operational amplifier and the first end of the eighth resistor, the second end of the eighth resistor is connected to the output terminal of the second operational amplifier, and their common end serves as the output terminal of the operational amplifier module 261.

[0067] Specifically, the fifth resistor R7 and the sixth resistor R8 form a voltage divider circuit, wherein one end of the fifth resistor R7 is grounded, one end of the sixth resistor R8 is connected to a second reference voltage, and the other ends of the fifth resistor R7 and the sixth resistor R8 are both connected to the non-inverting input of the second operational amplifier N1B. This divided voltage serves as the voltage at the non-inverting input of the second operational amplifier N1B. The sensitive chip 25 is connected to one end of the seventh resistor R9, the other end of which is connected to the inverting input of the second operational amplifier N1B. The two ends of the eighth resistor R10 are connected to the inverting input of the second operational amplifier N1B and the output of the second operational amplifier N1B, respectively. At this point, the output of the second operational amplifier N1B receives a conditioned voltage signal, providing an effective input for the voltage-to-current conversion module 262.

[0068] It is understood that the voltage obtained by dividing the second reference voltage by the fifth resistor R7 and the sixth resistor R8 is connected to the non-inverting input terminal of the second operational amplifier N1B. The output impedance of the sensor 25, the seventh resistor R9, the eighth resistor R10, and the second operational amplifier N1B form an inverting amplifier. The second reference voltage can be the same as or different from the first reference voltage. In this embodiment, for ease of control, the second reference voltage and the first reference voltage are both VDD.

[0069] 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, an inner cavity of the sensor housing is provided with a circuit board and a press sleeve, a first end of the circuit board is inserted into the bottom of the sensor housing, the press sleeve includes a press sleeve body with a central opening, the press sleeve body includes a fixing portion and a mounting portion connected to the fixing portion, the outer diameter of the fixing portion is smaller than the outer diameter of the mounting portion, an end of the fixing portion away from the mounting portion abuts against the second end of the circuit board, an outer surface of the mounting portion is fitted and connected to the inner wall of the sensor housing, a gap is provided between the outer surface of the fixing portion and the inner wall of the sensor housing, and the inner cavity of the sensor housing is poured with potting glue; an end of the fixing portion away from the mounting portion is further provided with a card groove for diversion, and an end surface of the mounting portion is provided with a through hole for ventilation; One end of the connecting cable passes through the central opening of the compression sleeve and is connected to the circuit board, and the other end of the connecting cable is connected to the electrical connector; The sensor probe further comprises a gland, wherein a first end surface of a bottom end of the gland abuts against an end of the mounting portion away from the fixing portion, and a sealing ring is provided between the first end surface of the bottom end of the gland and an end of the mounting portion away from the fixing portion, an outer surface of the bottom end of the gland cooperates with an inner wall of the sensor housing to axially compress the sealing ring, an end surface of the top end of the gland is provided with an opening for passing the connecting cable, and an inner surface of the bottom end of the gland is provided with a conical groove for installing the sealing ring; The sensor probe further includes a pressure cap and a sealing sleeve located inside the pressure cap, the outer sleeve of the connecting cable is provided with a hose, the inner wall of the pressure cap is matched with the outer wall of the sensor body, the pressure cap cooperates with the second end surface of the bottom end of the pressure cover to axially clamp the sealing sleeve, the inner wall of the sealing sleeve and the outer surface of the top end of the pressure cover form a receiving cavity for accommodating the hose, the inner wall of the sealing sleeve is provided with a plurality of first protrusions matched with the outer wall of the hose, and the outer surface of the top end of the pressure cover is provided with a plurality of second protrusions matched with the inner wall of the hose; A step plate for welding the pins of the temperature measuring element is provided at the first end of the circuit board, and the thickness of the step plate is smaller than the thickness of the circuit board itself; The side of the circuit board is equipped with a sensitive element and a signal conditioning circuit. The sensitive element is used to sense the vibration and impact physical quantity of the measured position and convert it into a voltage signal. The signal conditioning circuit is used to amplify the voltage signal output by the sensitive element and convert it into a current signal. The signal conditioning circuit includes an operational amplifier module, a voltage-current conversion module and an output current compensation module; The input end of the operational amplifier module is connected to the output end of the sensitive element, and is used to adjust the level voltage signal output by the sensitive element to a preset level; The input end of the voltage-current conversion module is connected to the output end of the operational amplifier module, and the output end of the voltage-current conversion module is connected to the input end of the post-stage detection system, for converting the voltage signal output by the operational amplifier module into a current signal; The input end of the output current compensation module is connected to a first reference voltage, and the output end of the output current compensation module is connected to the inverting input end of the operational amplifier in the voltage-current conversion module, so as to generate a corresponding compensation current according to the first reference voltage and input the compensation current into the voltage-current conversion module to compensate for its output current signal.

2. The sensor according to claim 1, characterized in that The outer periphery of the bottom of the sensor housing is provided with a first outer conical surface for signal transmission, the inner wall of the bottom of the sensor housing is also provided with an inner conical surface, and the outer periphery of the first end of the circuit board is provided with a second outer conical surface matching the inner conical surface.

3. The sensor according to claim 1, wherein The output current compensation module includes a first resistor, a first end of the first resistor serves as an input end of the output current compensation module, and a second end of the first resistor serves as an output end of the output current compensation module.

4. The sensor according to claim 3, characterized in that The voltage-current conversion module includes a second resistor, a third resistor, a fourth resistor, a first operational amplifier and an NMOS tube; The first end of the second resistor serves as the input end of the voltage-current conversion module, the second end of the second resistor is connected to the non-inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is respectively connected to the second end of the first resistor, the first end of the third resistor and the source of the NMOS tube, the second end of the third resistor is connected to the ground, the output end of the first operational amplifier is connected to the first end of the fourth resistor, the second end of the fourth resistor is connected to the gate of the NMOS tube, and the drain of the NMOS tube serves as the output end of the voltage-current conversion module.

5. The sensor according to claim 4, characterized in that The operational amplifier module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a second operational amplifier; The first end of the fifth resistor is connected to the ground, the second end of the fifth resistor is respectively connected to the non-inverting input terminal of the second operational amplifier and the first end of the sixth resistor, the second end of the sixth resistor is connected to the second reference voltage, the first end of the seventh resistor serves as the input terminal of the operational amplifier module, the second end of the seventh resistor is respectively connected to the inverting input terminal of the second operational amplifier and the first end of the eighth resistor, the second end of the eighth resistor is connected to the output terminal of the second operational amplifier, and their common end serves as the output terminal of the operational amplifier module.

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