Piezoelectric acceleration sensor

Abstract

The utility model relates to the technical field of acceleration sensors, in particular to a piezoelectric acceleration sensor, which comprises a shell, a mounting cavity is arranged in the shell, a shielding shell is fixedly connected in the mounting cavity, a crystal base is fixedly connected at the bottom end in the shielding shell, a PCB (printed circuit board) is arranged at the upper part in the shielding shell, and the crystal base is fixedly connected with the crystal base. An external force is applied along the polarization direction of the ceramic wafer to deform the ceramic wafer, the inside of the ceramic wafer is polarized, charges with opposite polarities appear on the two stressed end faces, and the ceramic wafer is recovered to an initial state if the external force is removed, so that mechanical energy is converted into electric energy by utilizing the direct piezoelectric effect of the ceramic wafer, and then the electric energy is subjected to signal processing; the sensor outputs 100mv / g alternating current voltage, so that vibration acceleration signals are measured, triangular shearing is adopted by a measuring element, a two-core shielding cable is adopted by a cable, and the sensor is small in size, light in weight and high in applicability.

Description

Technical Field

[0001] The utility model relates to the technical field of acceleration sensors, in particular to a piezoelectric acceleration sensor. Background Art

[0002] A piezoelectric accelerometer is a sensor that can measure acceleration. It works based on the piezoelectric effect, using the charge generated on the surface of a piezoelectric material when a force is applied to it. This sensor has the advantages of wide bandwidth, high sensitivity, high signal-to-noise ratio, simple structure, reliable operation, and light weight.

[0003] However, the traditional piezoelectric accelerometer ring shear method uses glue to bond the measuring element, and product consistency cannot be guaranteed. At the same time, the lateral sensitivity is low, and it cannot adapt to high or low environments, and the reliability is low. Utility Model Content

[0004] The utility model aims to provide a piezoelectric acceleration sensor, which has the characteristics of triangular shearing of measuring elements, two-core shielded cables, small size, light weight and strong applicability.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a piezoelectric acceleration sensor, comprising a shell, a mounting cavity being defined within the shell, a shielding shell being fixedly connected to the interior of the mounting cavity, a crystal base being fixedly connected to the inner bottom end of the shielding shell, a ceramic chip being provided on the upper end surface of the crystal base, a mass block being provided on the outer wall of the ceramic chip, a PCB being provided above the interior of the shielding shell, an upper cover being fixedly connected to the top of the shielding shell, and an insulating upper cover being provided above the upper cover.

[0006] In order to facilitate the connection of electrical circuits and the transmission of electrical signals, as a preferred piezoelectric acceleration sensor of the present invention, an aviation socket is fixedly connected to the top of the housing.

[0007] In order to fix the wafer and the mass block on the base, as a preferred embodiment of the piezoelectric acceleration sensor of the present invention, a copper pressure ring is sleeved on the outer wall of the mass block.

[0008] In order to prevent the base from being short-circuited with the metal housing, as a preferred embodiment of the piezoelectric acceleration sensor of the present invention, an insulating gasket is provided at the bottom of the crystal base.

[0009] In order to allow the lead to pass through and connect the socket probe with the PCB signal output end, as a preferred piezoelectric acceleration sensor of the present invention, the upper end surfaces of the upper cover and the insulating upper cover are both provided with through holes.

[0010] In order to improve the strength of the shell, as a preferred embodiment of the piezoelectric acceleration sensor of the present invention, the shell is made of metal.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] The ceramic chip is mounted on the crystal base, and the mass block is mounted on the ceramic chip to apply force to the ceramic chip during vibration. The output end of the ceramic chip is connected to the PCB board. When an external force is applied along the polarization direction of the ceramic chip to deform it, polarization occurs inside the ceramic chip, and charges of opposite polarity appear on the two end faces of the force. If the external force is removed, the ceramic chip returns to its initial state, thereby utilizing the positive piezoelectric effect of the ceramic chip to convert mechanical energy into electrical energy and then process the signal to make the sensor output an AC voltage of 100mv / g, thereby realizing the measurement of vibration acceleration signals. The measuring element adopts triangular shearing and the cable adopts a two-core shielded cable. The sensor is small in size, light in weight and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the overall external structure diagram of the utility model;

[0014] Figure 2 This is the overall cross-sectional structural diagram of the utility model;

[0015] Figure 3 This is a top view of the overall structure of the utility model.

[0016] In the figure: 1. Housing; 2. Mounting cavity; 3. Crystal base; 4. Ceramic wafer; 5. Mass block; 6. Shielding shell; 7. PCB board; 8. Top cover; 9. Aviation socket; 10. Copper pressure ring; 11. Insulating top cover; 12. Insulating gasket. DETAILED DESCRIPTION

[0017] See also Figures 1 to 3 A piezoelectric acceleration sensor includes a shell 1, an installation cavity 2 is opened inside the shell 1, a shielding shell 6 is fixedly connected to the inside of the installation cavity 2, a crystal base 3 is fixedly connected to the bottom end of the inner part of the shielding shell 6, a ceramic chip 4 is provided on the upper end surface of the crystal base 3, a mass block 5 is provided on the outer wall of the ceramic chip 4, a PCB board 7 is provided above the inside of the shielding shell 6, an upper cover 8 is fixedly connected to the top of the shielding shell 6, and an insulating upper cover 11 is provided above the upper cover 8.

[0018] In this embodiment: the ceramic chip 4 is mounted on the crystal base 3, and the mass block 5 is mounted on the ceramic chip 4 to apply force to the ceramic chip 4 during vibration. The output end of the ceramic chip 4 is connected to the PCB board 7. An external force is applied along the polarization direction of the ceramic chip 4 to deform it, then polarization occurs inside the ceramic chip 4, and charges of opposite polarity appear on the two end faces under force. If the external force is removed, the ceramic chip 4 returns to its initial state, thereby utilizing the positive piezoelectric effect of the ceramic chip 4 to convert mechanical energy into electrical energy and then, after signal processing, enable the sensor to output an AC voltage of 100mv / g, thereby realizing the measurement of the vibration acceleration signal. The measuring element adopts triangular shearing, and the cable adopts a two-core shielded cable. The sensor is small in size, light in weight, and has strong applicability.

[0019] As a technical optimization solution of the present invention, an aviation socket 9 is fixedly connected to the top of the housing 1 .

[0020] In this embodiment, an aviation socket 9 is fixedly connected to the top of the housing 1 to facilitate the connection of electrical circuits and the transmission of electrical signals.

[0021] As a technical optimization solution of the present invention, a copper pressure ring 10 is sleeved on the outer wall of the mass block 5 .

[0022] In this embodiment, a copper pressure ring 10 is sleeved on the outer wall of the mass block 5 to facilitate fixing the ceramic wafer 4 and the mass block 5 on the crystal base 3.

[0023] As a technical optimization solution of the present invention, an insulating gasket 12 is provided at the bottom of the crystal base 3 .

[0024] In this embodiment, an insulating gasket 12 is provided at the bottom of the crystal base 3 to prevent the crystal base 3 from being short-circuited with the housing 1 .

[0025] As a technical optimization solution of the present invention, through holes are provided on the upper end surfaces of the upper cover 8 and the insulating upper cover 11 .

[0026] In this embodiment, the upper end surfaces of the upper cover 8 and the insulating upper cover 11 are both provided with through holes for the wires to pass through and connect the socket probes with the signal output terminals of the PCB.

[0027] As a technical optimization solution of the present invention, the housing 1 is made of metal.

[0028] In this embodiment, the housing 1 is made of metal to increase strength and extend service life.

[0029] Working principle: The ceramic chip 4 is mounted on the crystal base 3, and the mass block 5 is mounted on the ceramic chip 4 to apply force to the ceramic chip 4 during vibration. The output end of the ceramic chip 4 is connected to the PCB board 7. An external force is applied along the polarization direction of the ceramic chip 4 to deform it, then polarization occurs inside the ceramic chip 4, and charges of opposite polarity appear on the two end faces of the force. If the external force is removed, the ceramic chip 4 returns to its initial state, thereby utilizing the positive piezoelectric effect of the ceramic chip 4 to convert mechanical energy into electrical energy and then process the signal to make the sensor output an AC voltage of 100mv / g, thereby realizing the measurement of vibration acceleration signals. The measuring element adopts triangular shearing and the cable adopts a two-core shielded cable. The sensor is small in size, light in weight and has strong applicability.

[0030] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A piezoelectric acceleration sensor, comprising a housing (1), characterized in that: The housing (1) is provided with an installation cavity (2), the installation cavity (2) is fixedly connected to a shielding shell (6), the bottom end of the shielding shell (6) is fixedly connected to a crystal base (3), the upper end surface of the crystal base (3) is provided with a ceramic chip (4), the outer wall of the ceramic chip (4) is provided with a mass block (5), a PCB board (7) is provided above the interior of the shielding shell (6), the top of the shielding shell (6) is fixedly connected to an upper cover (8), and an insulating upper cover (11) is provided above the upper cover (8).

2. The piezoelectric acceleration sensor according to claim 1, wherein: An aviation socket (9) is fixedly connected to the top of the housing (1).

3. The piezoelectric acceleration sensor according to claim 1, wherein: The outer wall of the mass block (5) is sleeved with a copper pressing ring (10).

4. The piezoelectric acceleration sensor according to claim 1, wherein: An insulating gasket (12) is provided at the bottom of the crystal base (3).

5. The piezoelectric acceleration sensor according to claim 1, wherein: The upper end surfaces of the upper cover (8) and the insulating upper cover (11) are both provided with through holes.

6. The piezoelectric acceleration sensor according to claim 1, wherein: The housing (1) is made of metal.

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