High-temperature reliability measuring system for sensitive element of pressure sensor

Abstract

The invention discloses a high-temperature reliability measurement system for a sensitive element of a pressure sensor. The high-temperature reliability measurement system comprises an alternating force driver, a high-temperature test box, a high-temperature detection module, a normal-temperature comparison module and a detection circuit, a temperature control unit is arranged in the high-temperature test box, a to-be-tested quartz crystal is clamped between a high-temperature upper electrode and a high-temperature lower electrode of the high-temperature detection module, and a standard quartz crystal is arranged between two normal-temperature electrodes of the normal-temperature comparison module; the high-temperature detection module and the normal-temperature comparison module are coaxial and are connected in series through the insulating column to form an integrated stress structure, and the alternating force driver generates equal low-frequency alternating force to be synchronously loaded to the high-temperature detection module and the normal-temperature comparison module; the measurement system is simple in structure, high in operability and high in measurement precision, the high-temperature detection module and the normal-temperature comparison module are connected in series to form an integrated stress structure, synchronism and equivalent input of alternating force are guaranteed, and the measurement accuracy is improved by comparing output of a to-be-measured quartz crystal in a high-temperature environment with output of a quartz crystal at a normal temperature. And the high-temperature output error of the pressure sensor is obviously and accurately measured.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor performance detection, and specifically refers to a high-temperature reliability measurement system for a sensitive element of a pressure sensor. Background Art

[0002] As an internal key sensitive element of an internal combustion engine combustion pressure sensor, a quartz crystal has a risk of high-temperature failure at high temperatures inside the cylinder of a high-power density internal combustion engine and cannot meet the needs of internal combustion engine measurement research. Therefore, it is necessary to study the high-temperature failure mechanism of the sensitive element - the quartz crystal.

[0003] The failure of the quartz crystal caused by high temperature may manifest as insufficient sensitivity, unstable signals, or even complete failure. The existing high-temperature reliability tests are relatively simple and arbitrary. By collecting the pressure signals of the quartz crystal in a high-temperature environment to roughly judge the failure phenomenon, only obvious failure phenomena can be simply judged, and the failure mechanism of the quartz crystal cannot be accurately grasped, which is not suitable for the high-temperature reliability research in the process of improving the design of the quartz crystal. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a measurement system for measuring the high-temperature reliability of a sensitive element of an internal combustion engine combustion pressure sensor, so as to overcome one or more problems caused by the limitations and defects of the related technology to a certain extent.

[0005] In order to achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A high-temperature reliability measurement system for a sensitive element of a pressure sensor includes an alternating force driver, a high-temperature test chamber, a high-temperature detection module, a normal-temperature comparison module, and a detection circuit; wherein,

[0007] The detection circuit includes a high-temperature branch and a normal-temperature branch, and is used to collect the high-temperature voltage detected by the high-temperature branch and the standard voltage detected by the normal-temperature branch;

[0008] A temperature control unit is arranged in the high-temperature test chamber; the high-temperature detection module is arranged in the high-temperature test chamber, and it includes a high-temperature upper electrode and a high-temperature lower electrode that are electrically connected to the high-temperature branch, and the quartz crystal to be tested is clamped between the high-temperature upper electrode and the high-temperature lower electrode;

[0009] The normal-temperature comparison module is located outside the high-temperature test chamber, and it includes two normal-temperature electrodes that are electrically connected to the normal-temperature branch, and a standard quartz crystal is arranged between the two normal-temperature electrodes;

[0010] The high-temperature detection module and the normal-temperature comparison module are coaxial, and the proximal ends of the two are connected in series through an insulating and heat-insulating column to form an integral stress structure. The alternating force driver applies an axial alternating force from the distal end of the high-temperature detection module or the normal-temperature comparison module, and is used to generate an equal amount of low-frequency alternating force and synchronously load it onto the quartz crystal under test and the standard quartz crystal.

[0011] Furthermore, the high-temperature detection module further includes a clamping column and a guiding column. The high-temperature upper electrode is installed at the lower end of the clamping column. The clamping column is threadedly installed on the top of the high-temperature test chamber. A clamping handle for driving the clamping column to move axially for clamping is arranged outside the high-temperature test chamber. The guiding column is vertically slidably arranged in a stepped hole on the inner bottom surface of the high-temperature test chamber and is connected to the insulating and heat-insulating column. The alternating force driver is arranged at the lower end of the normal-temperature comparison module.

[0012] Even further, a deformation cavity is arranged at the lower end of the clamping column, an expansion spring is arranged in the deformation cavity, and the upper end of the high-temperature upper electrode is clamped in the deformation cavity and supported by the expansion spring.

[0013] Furthermore, the alternating force driver is an electromagnetic driver. The movable iron core of the alternating force driver is arranged axially. The upper end of the movable iron core abuts against the bottom end of the normal-temperature comparison module, and its lower end is seated on the bottom of the driving shell of the alternating force driver. A buffer spring is embedded at the bottom of the driving shell for buffering the return action of the movable iron core.

[0014] Furthermore, both the high-temperature branch and the normal-temperature branch include a parallel capacitor and a voltage output branch. The parallel capacitor is used to collect the pressure charge generated on the quartz crystal under test or the standard quartz crystal and establish a dynamic output voltage, and the dynamic output voltage is collected through the voltage output branch.

[0015] Furthermore, the detection circuit further includes a division circuit. The two input terminals of the division circuit respectively input the dynamic output voltages of the high-temperature branch and the normal-temperature branch, and are used to amplify and output and display the ratio K of the two dynamic output voltages.

[0016] Compared with the prior art, the high-temperature reliability measurement system for the sensitive element of the pressure sensor of the present invention has the following beneficial effects:

[0017] This measurement system is provided with a normal-temperature comparison module. The high-temperature detection module and the normal-temperature comparison module are connected in series to form an integral stress structure, which ensures the synchronism and equal input of the alternating force. By comparing the outputs of the quartz crystal under test in a high-temperature environment and the quartz crystal at normal temperature, the high-temperature output error of the pressure sensor is significantly and accurately measured, which is beneficial to studying the failure mechanism of the quartz crystal; this measurement system has a simple structure, strong operability, high measurement accuracy, and is suitable for accurately measuring the high-temperature reliability of the sensitive element in the pressure sensor. Description of the Drawings

[0018] Figure 1This is a schematic structural diagram of the high-temperature reliability measurement system of the present invention.

[0019] In the figure: 1, clamping handle; 2, high-temperature test chamber; 3, clamping column; 4, expansion spring; 5, high-temperature upper electrode; 6, quartz crystal to be measured; 7, high-temperature lower electrode; 8, guiding column; 9, insulating and heat-insulating column; 10, normal-temperature electrode; 11, standard quartz crystal; 12, alternating force driver; 121, moving iron core; 13, alternating circuit; 14, normal-temperature branch; 15, high-temperature branch. Specific embodiments

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only the best embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] This embodiment provides a high-temperature reliability measurement system for the sensitive element of a pressure sensor. Under the action of equal pressure, the reliability is evaluated by comparing the pressure signal output of the quartz crystal 6 to be measured in a high-temperature environment with the pressure signal output of the standard quartz crystal 11 at normal temperature, as Figure 1 shown. The high-temperature reliability measurement system includes an alternating force driver 12, a high-temperature test chamber 2, a high-temperature detection module, a normal-temperature comparison module, and a detection circuit;

[0022] A temperature control unit is arranged in the high-temperature test chamber 2. The temperature control unit heats the test environment in the high-temperature test chamber 2 according to the preset heating temperature, and maintains the environmental temperature after reaching the preset heating temperature; an operation hatch and an observation window are opened on the high-temperature test chamber 2 to facilitate the placement of the quartz crystal 6 to be measured and observe the clamping state and test state;

[0023] The high-temperature detection module and the normal-temperature comparison module are coaxially arranged, and the proximal ends of the two are connected in series through the insulating and heat-insulating column 9 to form an integral stress structure; among them, the high-temperature detection module is arranged in the high-temperature test chamber 2 and includes a high-temperature upper electrode 5 and a high-temperature lower electrode 7. The quartz crystal 6 to be measured is clamped between the high-temperature upper electrode 5 and the high-temperature lower electrode 7. The high-temperature upper electrode 5 is supported by the clamping column 3 at the top inside the high-temperature test chamber 2, and the high-temperature lower electrode 7 is supported by the insulating and heat-insulating column 9 below; the normal-temperature comparison module is arranged outside the high-temperature test chamber 2 and includes a normal-temperature upper electrode and a normal-temperature lower electrode. The normal-temperature upper electrode is supported by the insulating and heat-insulating column 9, and the normal-temperature lower electrode is supported by an insulating base;

[0024] The alternating force driver 12 can be disposed directly below the base or directly above the clamping column 3. It simulates the cylinder pressure to generate a reciprocating alternating force along the axis of the high-temperature detection module and the normal-temperature comparison module. An axial alternating force is applied from the upper end of the high-temperature detection module or the lower end of the normal-temperature comparison module, generating an equal amount of low-frequency alternating force on the integrally stressed structure formed in series and synchronously loading it onto the quartz crystal 6 to be measured and the standard quartz crystal 11.

[0025] The detection circuit includes a high-temperature branch 15 and a normal-temperature branch 14. The high-temperature branch 15 collects the piezoelectric charges of the high-temperature detection module and forms a high-temperature voltage for output display or comparison. The normal-temperature branch 14 collects the piezoelectric charges of the normal-temperature comparison module and forms a standard voltage for output display or comparison. As Figure 1 shown, the high-temperature branch 15 includes a parallel capacitor C 1 and a high-temperature voltage output branch. The two ends of the parallel capacitor C 1 are respectively connected to the high-temperature upper electrode 5 and the high-temperature lower electrode 7, which are used to collect the piezoelectric charges generated by the alternating force on the quartz crystal 6 to be measured and establish a dynamic high-temperature voltage. The dynamic high-temperature voltage is collected by the high-temperature voltage output branch connected to the two ends of the parallel capacitor C 1 . The high-temperature voltage output branch can be connected to a pressure gauge for pressure display, or grounded to form a differential pressure end and connected to one end of a division circuit (not shown in the figure) to form U 1 for input. Similarly, the normal-temperature branch 14 includes a parallel capacitor C 2 and a standard voltage output branch. The two ends of the parallel capacitor C 2 are respectively connected to the normal-temperature upper electrode and the normal-temperature lower electrode to establish a dynamic standard voltage. The dynamic standard voltage is collected through the standard voltage output branch. The standard voltage output branch can be connected to a pressure gauge for pressure display, or grounded to form a differential pressure end and connected to the other end of the division circuit to form U2 for input. The division circuit is a prior art, which can amplify and output the ratio K (i.e., U1 / U2) of the two input voltages for display. Under normal conditions, the voltage ratio K remains unchanged. When K changes, it can be determined that the quartz crystal 6 to be measured has a high-temperature failure. Record the relationship between the change law of the ratio K and the ambient temperature to explore the high-temperature failure mechanism of the quartz crystal 6 to be measured.

[0026] As a further technical solution, to facilitate the placement and clamping of the quartz crystal 6 to be measured, the clamping column 3 is threadedly installed on the top of the high-temperature test chamber 2 and fixedly connected to the clamping handle 1 outside the high-temperature test chamber 2. By rotating the clamping column 3, the clamping handle 1 drives the clamping column 3 to move axially for clamping. Additionally, to better support and install the electrode 7 at high temperatures and construct an equal-force community between the quartz crystal 6 to be measured and the standard quartz crystal 11, the electrode 7 at high temperatures is installed on the guiding column 8. A stepped hole is provided on the inner bottom surface of the high-temperature test chamber 2. The guiding column 8 is slidably arranged in the stepped hole, and its lower end is connected to the insulating and heat-insulating column 9. The quartz crystal 6 to be measured is completely supported by the insulating and heat-insulating column 9. In this way, the alternating force is equally transmitted to the quartz crystal 6 to be measured by the insulating and heat-insulating column 9, and the expansion force generated by the quartz crystal 6 to be measured at high temperatures is equally transmitted to the standard quartz crystal 11, improving the detection accuracy;

[0027] Additionally, considering the expansion and deformation of the quartz crystal 6 to be measured, the upper electrode 5 at high temperatures is in an elastic support state to provide a deformable amount. Referring again to Figure 1 , a deformation cavity is provided at the lower end of the clamping column 3. The upper end of the upper electrode 5 at high temperatures is clamped in the deformation cavity, and an expansion spring 4 is arranged in the deformation cavity. The upper electrode 5 at high temperatures is provided with an elastic support force by the expansion spring 4;

[0028] In this embodiment, an electromagnetic driver is preferably used as the alternating force driver 12 to provide a reciprocating alternating force. The electromagnetic driver is connected to an alternating circuit 13, and the alternating current makes it generate a low-frequency alternating force. The electromagnetic driver includes a driving shell, a driving coil, and a movable iron core 121. The movable iron core 121 is coaxially arranged inside the driving coil. When an alternating current is passed through, a driving force can be generated to push the movable iron core 121 to move axially back and forth. The upper end of the movable iron core 121 abuts against the bottom end of the base. When not energized, the lower end of the movable iron core 121 sits on the bottom of the driving shell of the alternating force driver 12. To buffer the return movement of the movable iron core 121, a buffer spring is embedded at the bottom of the driving shell.

[0029] The orientation terms such as "upper", "lower", "side", "end", "bottom", "inner", "outer", etc. mentioned in this article are based on the orientation or positional relationship shown in the corresponding drawings in Figure 1 . These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated device, component, or part must have a specific orientation, or be constructed and operated in a specific orientation;

[0030] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the terms "upper", "inner", etc. may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to the specific situation.

[0031] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high temperature reliability measurement system for pressure sensor sensitive elements, characterized in that: It includes an alternating force driver, a high temperature test chamber, a high temperature detection module, a normal temperature comparison module and a detection circuit; wherein, The detection circuit includes a high temperature branch and a normal temperature branch, which are used to collect high temperature voltage and standard voltage; A temperature control unit is provided in the high temperature test box; the high temperature detection module is provided in the high temperature test box, and comprises a high temperature upper electrode and a high temperature lower electrode electrically connected to the high temperature branch, and the quartz crystal to be tested is sandwiched between the high temperature upper electrode and the high temperature lower electrode; The normal temperature comparison module is located outside the high temperature test box, and includes two normal temperature electrodes electrically connected to the normal temperature branch, and a standard quartz crystal is arranged between the two normal temperature electrodes; The high temperature detection module and the normal temperature comparison module are coaxial, and the proximal ends of the two are connected in series through insulating and heat-insulating columns to form an integrated force-bearing structure. The alternating force driver applies an alternating force along the axial direction from the distal end of the high temperature detection module or the normal temperature comparison module to generate an equal amount of low-frequency alternating force and synchronously load it onto the quartz crystal to be tested and the standard quartz crystal.

2. The high temperature reliability measurement system for pressure sensor sensitive elements according to claim 1, characterized in that: The high temperature detection module also includes a clamping column and a guide column. The high temperature upper electrode is installed at the lower end of the clamping column. The clamping column is threadedly installed on the top of the high temperature test box. A clamping handle for driving the clamping column to move axially and clamp is provided outside the high temperature test box. The guide column can be vertically slid in the step hole on the bottom surface of the high temperature test box, and is connected to the insulating and heat-insulating column. The alternating force driver is arranged at the lower end of the normal temperature comparison module.

3. The high temperature reliability measurement system for pressure sensor sensitive elements according to claim 2, characterized in that: The lower end of the clamping column is provided with a deformation cavity, and an expansion spring is provided in the deformation cavity. The upper end of the high-temperature upper electrode is clamped in the deformation cavity and supported by the expansion spring.

4. The high temperature reliability measurement system for pressure sensor sensitive elements according to claim 3, characterized in that: The alternating force driver is an electromagnetic driver. The movable iron core of the alternating force driver is arranged axially. The upper end of the movable iron core is mounted on the bottom end of the normal temperature comparison module, and the lower end is seated on the bottom of the drive shell of the alternating force driver. A buffer spring is embedded in the bottom of the drive shell to buffer the return action of the movable iron core.

5. The high temperature reliability measurement system for pressure sensor sensitive elements according to claim 1, characterized in that: The high temperature branch and the normal temperature branch both include a parallel capacitor and a voltage output branch. The parallel capacitor is used to collect the pressure charge generated on the quartz crystal to be tested or the standard quartz crystal and establish a dynamic output voltage. The dynamic output voltage is collected through the voltage output branch.

6. The high temperature reliability measurement system for pressure sensor sensitive elements according to claim 5, characterized in that: The detection circuit also includes a division circuit, and the two input ends of the division circuit respectively input the dynamic output voltages of the high-temperature branch and the normal-temperature branch, and are used to amplify and output the ratio K of the two dynamic output voltages for display.

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