Wide-range impact sensor

Abstract

The utility model discloses a wide-range impact sensor, which relates to the technical field of impact sensors and comprises a base, the base is connected with the bottom of a shell, the top of the shell is connected with a connector, the bottom of the connector is connected with the top of a wire, the bottom of the wire is connected with the top of an electrode, and piezoelectric ceramics are arranged on the upper side and the lower side of the electrode. The piezoelectric ceramics at the bottom of the electrode abut against the top end of the base, the top of the piezoelectric ceramics at the top of the electrode abuts against the bottom of the mass block, the mass block is located in the pre-tightening nut and abuts against the pre-tightening nut, the pre-tightening nut is in threaded connection with the base, and the mass block, the piezoelectric ceramics and the outer wall of the electrode are integrally wound with polyimide adhesive tape used for insulation. The utility model has the advantages of compact and small structure, high stability, strong weatherability, convenient installation and later maintenance, and can adjust the sensitivity parameter by adjusting the size and the superposition number of the piezoelectric ceramics so as to meet the customized requirements of customers.

Description

Technical Field

[0001] The utility model relates to the technical field of impact sensors, and particularly relates to a large-range impact sensor. Background Art

[0002] An impact sensor is a type of acceleration sensor, generally used to monitor the vibration conditions in short-time large-impact scenarios. The vibration level at the measured position can reach tens of thousands of g within a time of less than 10 microseconds. Such extremely fast transient vibration parameters and capricious impact levels pose higher requirements for the measurement range and impact limit of the test sensor. A piezoelectric impact sensor is a vibration measurement component made using the positive piezoelectric effect of piezoelectric elements. Compared with other types of acceleration sensors, it has the characteristics of good stability, high repeatability, simple structure, not easy to age, and high sensitivity, and is widely used in industrial fields such as industry, aviation, navigation, and ordnance. Currently, common impact sensors generally have relatively large volume and mass, and the upper limit of the working measurement range is about 20,000 g. Beyond this measurement range, the structure and function of the sensor will collapse. Therefore, there is an urgent need for a large-range impact sensor to solve the above problems. Content of the Utility Model

[0003] The purpose of the embodiment of the utility model is to provide a large-range impact sensor to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the utility model provides the following technical solution:

[0005] A large-range impact sensor includes a base. An external thread is provided on the outer wall of the top of the base. The base is connected to the bottom of the housing. A through hole one is provided at the top of the housing. The top of the housing is connected to a connector. The connector is arranged inside the through hole one. The bottom of the connector is connected to the top end of a wire. The bottom end of the wire is connected to the top of an electrode. Piezoelectric ceramics are provided on both the upper and lower sides of the electrode. One group of the piezoelectric ceramics located at the bottom of the electrode abuts against the top end of the base. A through hole two for the wire to pass through is provided at the central part of the other group of piezoelectric ceramics located at the top of the electrode. The top of the piezoelectric ceramics located at the top of the electrode abuts against the bottom of a mass block. A through hole three for the wire to pass through is provided at the central part of the mass block. The mass block is located inside a pre-tightening nut and abuts against it. A through hole four for the wire to pass through is provided at the central part of the pre-tightening nut. An internal thread is provided on the inner wall of the pre-tightening nut. The pre-tightening nut is threadedly connected to the base. The mass block, piezoelectric ceramics, and the outer walls of the electrode are integrally wound with a polyimide tape for insulation.

[0006] Compared with the prior art, the beneficial effects of the utility model are:

[0007] 1. The sensitivity parameter of the present utility model can be adjusted by adjusting the size and stacking quantity of piezoelectric ceramics to meet the customized requirements of customers;

[0008] 2. The structure of the present utility model is compact and small, with high stability and strong weather resistance, which is convenient for installation and later maintenance;

[0009] 3. The surface roughness of the measurement surface of the present utility model is below 0.8 Ra, which can effectively reduce the measurement error caused by installation defects (such as the influence of installation on the upper limit of the resonance frequency);

[0010] 4. The present utility model adopts an all-metal shell and a fully welded design, which can effectively protect the internal sensitive parts and shield external electromagnetic interference at the same time;

[0011] 5. The output signal of the present utility model can be expanded by an external charge amplifier, which can meet the usage requirements of different systems of customers;

[0012] 6. The present utility model can change its own frequency characteristics by adjusting the internal pre-tightening force to meet the requirements of frequency response at different installation positions;

[0013] 7. The overall structure of the present utility model can withstand an impact of more than 50000 g and stably output signals. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a large-range impact sensor in an embodiment of the present utility model.

[0015] Figure 2 It is a cross-sectional view of a large-range impact sensor in an embodiment of the present utility model.

[0016] Figure 3 It is an exploded schematic structural diagram of a large-range impact sensor in an embodiment of the present utility model.

[0017] In the figure: 1. Connector; 2. Wire; 3. Shell; 4. Pre-tightening nut; 5. Mass block; 6. Polyimide tape; 7. Electrode; 8. Piezoelectric ceramic; 9. Base. Specific Embodiments

[0018] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0019] In the embodiments of the present utility model, please refer to Figures 1 to 3, A large-range impact sensor, including a base 9, an external thread is provided on the outer wall of the top of the base 9, the base 9 is connected to the bottom of the housing 3, a through hole 1 is provided at the top of the housing 3, the top of the housing 3 is connected to the connector 1, the connector 1 is arranged inside the through hole 1, the bottom of the connector 1 is connected to the top end of the wire 2, the bottom end of the wire 2 is connected to the top of the electrode 7, piezoelectric ceramics 8 are provided on both the upper and lower sides of the electrode 7, a group of the piezoelectric ceramics 8 located at the bottom of the electrode 7 abuts against the top end of the base 9, a through hole 2 for the wire 2 to pass through is provided in the central part of the other group of the piezoelectric ceramics 8 located at the top of the electrode 7, the top of the piezoelectric ceramics 8 located at the top of the electrode 7 abuts against the bottom of the mass block 5, a through hole 3 for the wire 2 to pass through is provided in the central part of the mass block 5, the mass block 5 is located inside the pre-tightening nut 4 and abuts against it, a through hole 4 for the wire 2 to pass through is provided in the central part of the pre-tightening nut 4, internal threads are provided on the inner wall of the pre-tightening nut 4, the pre-tightening nut 4 is threadedly connected to the base 9, and polyimide tape 6 for insulation is wound around the outer walls of the mass block 5, piezoelectric ceramics 8 and electrode 7.

[0020] The housing 3 of the present utility model is made of 304 stainless steel and copper, and the overall temperature tolerance reaches above 200°C; high-temperature piezoelectric ceramic chips are selected for the present utility model, with a Curie temperature above 840°C. The high-temperature piezoelectric ceramic chips will not affect polarization at the upper limit of the designed temperature (200°C), and the piezoelectric parameters will not change, having very high stability.

[0021] The present utility model can obtain various sensitivity parameters and frequency response parameters by modifying the size, quantity of the piezoelectric ceramics 8 and the structures of other internal parts.

[0022] The connector 1 and the housing 3, the housing 3 and the base 9 are both fixed by laser welding. After the pre-tightening nut 4 and the base 9 are threadedly connected together, laser welding is used for fixation again. The piezoelectric ceramics 8 are in a parallel form to improve sensitivity. The piezoelectric ceramics 8, electrode 7 and mass block 5 are pressed together by the pre-tightening nut 4 and the base 9, and the overall is wound with polyimide tape 6 for insulation, and then the base 9 and the pre-tightening nut 4 are welded and fixed; welding is used for fixation between the electrode 7 and the wire 2, and welding is used for fixation between the wire 2 and the connector 1.

[0023] The overall structure of the present utility model can withstand impacts above 50000g and output stably.

[0024] The present utility model is installed on the surface of the measured part. The vibration physical quantity of the measured object is conducted to the internal sensitive part through the base 9. When the piezoelectric ceramics 8 are subjected to mechanical force, they will deform, and charges proportional to the vibration level will be generated on the ceramic surface. Thus, the sensitive part converts the detected vibration signal into an available electrical signal and outputs it through the wire 2 and the connector 1.

[0025] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and the present utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present utility model. Any reference signs in the claims should not be construed as limiting the claims involved.

[0026] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A large-range impact sensor, characterized in that, It includes a base. An external thread is provided on the outer wall of the top of the base. The base is connected to the bottom of the housing. A through hole 1 is provided at the top of the housing. The top of the housing is connected to a connector. The connector is arranged inside the through hole 1. The bottom of the connector is connected to the top end of a wire. The bottom end of the wire is connected to the top of an electrode. Piezoelectric ceramics are provided on both the upper and lower sides of the electrode. One set of the piezoelectric ceramics located at the bottom of the electrode abuts against the top end of the base. A through hole 2 for the wire to pass through is provided at the central part of the other set of the piezoelectric ceramics located at the top of the electrode. The top of the piezoelectric ceramics located at the top of the electrode abuts against the bottom of a mass block. A through hole 3 for the wire to pass through is provided at the central part of the mass block. The mass block is located inside a pre-tightening nut and abuts against it. A through hole 4 for the wire to pass through is provided at the central part of the pre-tightening nut. Internal threads are provided on the inner wall of the pre-tightening nut. The pre-tightening nut is threadedly connected to the base. The outer walls of the mass block, piezoelectric ceramics and electrode are integrally wound with polyimide tape for insulation.

2. The large-range impact sensor according to claim 1, characterized in that, The housing is made of stainless steel and copper.

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