Piezoelectric acceleration sensor

Abstract

The utility model relates to the field of sensors, and provides a piezoelectric acceleration sensor, which comprises a frame body, a probe and a sensing unit, the sensing unit comprises a shielding case, a mass block, piezoelectric ceramics and a signal line, one sub-line of the signal line is arranged on the shielding case, the other sub-line of the signal line penetrates through the shielding case and is arranged on the mass block, the signal line and the shielding case are arranged in a sealed mode, and the opening end of the shielding case is arranged on the other side face of the frame body. The probe is used for capturing a signal of a detected surface, the frame body and the mass block are used for detecting the shearing effect, and the piezoelectric ceramic has the piezoelectric effect and can convert mechanical energy into electric energy. When the piezoelectric ceramic deforms, positive charges and negative charges are generated on the inner surface and the outer surface respectively, the inner surface and the outer surface are plated with gold to form positive and negative electrodes, generated positive and negative signals are transmitted to the frame body and the mass block and output through the signal line, and corresponding detection and transmission effects are formed. The whole sensor is simple in structure and convenient to assemble.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of sensor, concretely relates to a piezoelectric acceleration sensor. BACKGROUND

[0002] Vibration measurement generally refers to surveying the vibration of equipment, and determining whether bearing, gear or lubrication fails through frequency spectrum characteristics, and finally measuring the health state of equipment. In industrial application, most of the rotating mechanical equipment uses bearing elements and gear transmission, and early failure of gear and bearing is reflected in the high frequency end of vibration signal.

[0003] The piezoelectric acceleration sensor is a passive sensor, which utilizes the piezoelectric effect of the piezoelectric crystal. When the acceleration sensor senses vibration, the force of the mass block on the piezoelectric element also changes, which can output an electric charge proportional to the vibration amount and transmit to the subsequent collector, so as to monitor the vibration value. The existing piezoelectric acceleration sensor usually adopts positive end compression type and plane shear type structure, but these structures are relatively complex, and are not conducive to the miniaturization of products, and the cost is also relatively high. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a piezoelectric acceleration sensor, which aims at improving the problem of complex product structure or large size of the existing piezoelectric acceleration sensor.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a piezoelectric acceleration sensor, comprising:

[0006] A frame body;

[0007] A probe arranged on one side surface of the frame body; and

[0008] A sensing unit comprising a shielding cover, a mass block sleeved in the shielding cover, a piezoelectric ceramic sleeved in the mass block, and a signal line, one sub-line of the signal line is arranged on the shielding cover, another sub-line of the signal line is arranged on the mass block through the shielding cover, and the signal line and the shielding cover are sealed, and the open end of the shielding cover is arranged on the other side surface of the frame body.

[0009] Preferably, the head of the probe is arc-shaped structure.

[0010] Preferably, the tail of the probe is provided with a connecting part, and the frame body is provided with a fixing part locked or separated with the connecting part.

[0011] Preferably, the surface of the frame body is provided with a tin layer.

[0012] A tin sheet is arranged between the mass and the piezoelectric ceramic.

[0013] A nut is further arranged, a first external thread is arranged on the outer side of the shield, a second external thread is arranged on the frame, and the nut is engaged with the first external thread and the second external thread.

[0014] A convex shaft for sleeving the piezoelectric ceramic is arranged on the other side of the frame.

[0015] Compared with the background art, the piezoelectric acceleration sensor has the following advantages:

[0016] 1. After the probe and the sensing unit are installed through the frame, the probe captures the signal of the measured surface, and the frame and the mass are used for shear effect detection. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a structural schematic diagram of a piezoelectric acceleration sensor according to the present application;

[0018] Figure 2 FIG. 3 is a structural schematic diagram of a shield of a piezoelectric acceleration sensor according to the present application;

[0019] Figure 3 FIG. 4 is a structural schematic diagram of a frame of a piezoelectric acceleration sensor according to the present application;

[0020] Figure 4 FIG. 5 is a structural schematic diagram of a probe of a piezoelectric acceleration sensor according to the present application.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 10, frame; 101, fixed part; 102, tin layer; 103, second external thread; 104, convex shaft;

[0023] 20, probe; 201, arc surface structure; 202, connecting part;

[0024] 30, sensing unit; 301, shield; 302, mass; 303, piezoelectric ceramic; 304, signal line; 305, tin sheet;

[0025] 3011, first external thread;

[0026] 40. Nut. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the utility model is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0028] In addition, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the orientation or positional relationship shown in the drawings and are merely used for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements of the utility model must have a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0029] When an element is referred to as being "fixed to" or "set to" or "provided on" another element, it can be directly on the other element or indirectly 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.

[0030] Unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0031] Embodiment

[0032] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , the present embodiment provides a piezoelectric acceleration sensor, which comprises a frame body 10, a probe 20 and a sensing unit 30, the probe 20 is arranged on one side surface of the frame body 10; the sensing unit 30 comprises a shielding cover 301, a mass block 302 sleeved in the shielding cover 301, a piezoelectric ceramic 303 sleeved in the mass block 302 and a signal line 304, one sub-line of the signal line 304 is arranged on the shielding cover 301, the other sub-line of the signal line 304 is arranged on the mass block 302 through the shielding cover 301, and the signal line 304 and the shielding cover 301 are sealingly arranged, and the open end of the shielding cover 301 is arranged on the other side surface of the frame body 10.

[0033] Specifically, after the probe 20 and the sensing unit 30 are installed through the frame 10, the signal of the measured surface is captured through the probe 20. The frame and the mass 302 are used to detect the shearing effect, the piezoelectric ceramic 303 has the piezoelectric effect and can convert mechanical energy into electrical energy. When the piezoelectric ceramic 303 is deformed, positive and negative charges are generated on the inner and outer surfaces respectively, the inner and outer surfaces are plated with gold to form positive and negative electrodes, and the generated positive and negative signals are transmitted to the frame and the mass 302, and are output through the signal line 304 to form the corresponding detection transmission effect. The whole sensor structure is simple and convenient to assemble.

[0034] Further, the head of the probe 20 in the embodiment is an arc surface structure 201, for example, the probe 20 with a ball head structure can more conveniently capture the signal of the measured surface, and improve the detection accuracy and practicability.

[0035] As shown in Figure 4 , the tail of the probe 20 in the embodiment is provided with a connecting part 202, and the frame 10 is provided with a fixing part 101 which is locked or separated with the connecting part 202. For example, the connecting part 202 is a threaded shaft, and the fixing part 101 is a threaded groove, which can be matched through the structure of thread engagement, so as to fix and install the probe 20 on the frame 10. Also, different probes 20 can be replaced for use; the effect of convenient replacement or maintenance is achieved.

[0036] Further, the shielding cover 301 can be made of stainless steel material, which has the advantages of good appearance gloss and strong corrosion resistance. The shielding cover 301 mainly functions to protect the piezoelectric ceramic 303 from being affected by dust or water vapor in the external environment; at the same time, a complete shielding loop is formed to prevent charge leakage or external interference, and good protection is achieved.

[0037] Also, as shown in Figure 1 , the embodiment further includes a nut 40, the outer side of the shielding cover 301 is provided with a first external thread 3011, the frame 10 is provided with a second external thread 103, and the nut 40 is simultaneously engaged on the first external thread 3011 and the second external thread 103, so that the nut 40 is used for butt sealing and fixing, and the effect of connecting and installing the shielding cover 301 is achieved, and the structure is simple and convenient to disassemble and assemble.

[0038] As shown in Figure 1 , the surface of the frame in the embodiment is provided with a tin layer 102. Specifically, the frame can be made of stainless steel material, and a layer of tin layer 102 is electroplated on the surface of the frame to form protection for the frame and facilitate the conduction of electrical signals.

[0039] As shown in Figure 1As shown, in the embodiment, the tin sheet 305 is arranged between the mass 302 and the piezoelectric ceramic 303, the mass 302 can be made of tungsten alloy (density is 16.5-18.75 g / cm3, having higher density), so that the mass 302 has larger weight under the same volume, thereby providing the sensitivity of the sensor, because the sensitivity of the sensor is proportional to the weight of the mass 302, and the piezoelectric ceramic 303 can be plated with tin on the surface, so that after the tin is plated on the surface of the mass 302, the tin sheet 305 is conveniently connected between the mass 302 and the piezoelectric ceramic 303, and the effect of current transmission is formed.

[0040] As shown in the drawings, Figure 3 As shown, in the embodiment, the other side of the frame body 10 is provided with the convex shaft 104 for sleeving the piezoelectric ceramic 303. Thus, after the mass 302 and the piezoelectric ceramic 303 are sleeved and installed, the piezoelectric ceramic 303 and the frame body form the shearing effect.

[0041] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A piezoelectric accelerometer, characterized in that, include: Frame; A probe is disposed on one side of the frame; and The sensing unit includes a shield, a mass block fitted inside the shield, a piezoelectric ceramic fitted inside the mass block, and a signal line. One sub-wire of the signal line is disposed on the shield, and the other sub-wire of the signal line passes through the shield and is disposed on the mass block. The signal line and the shield are sealed together. The open end of the shield is disposed on the other side of the frame.

2. The piezoelectric accelerometer according to claim 1, characterized in that: The probe head has an arc-shaped structure.

3. The piezoelectric accelerometer according to claim 1 or 2, characterized in that: The probe has a connecting part at its tail, and the frame has a fixing part that can be locked or detached from the connecting part.

4. The piezoelectric accelerometer according to claim 1, characterized in that: The surface of the frame is provided with a tin layer.

5. The piezoelectric accelerometer according to claim 1, characterized in that: A tin sheet is disposed between the mass block and the piezoelectric ceramic.

6. The piezoelectric accelerometer according to claim 1, 4, or 5, characterized in that: It also includes a nut, with a first external thread on the outer surface of the shield and a second external thread on the frame, and the nut is simultaneously engaged with the first external thread and the second external thread.

7. The piezoelectric accelerometer according to claim 1, 4, or 5, characterized in that: A convex shaft is provided on the other side of the frame for the piezoelectric ceramic to be fitted.

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