CN105606200A - Three-axial vibration sensor structure - Google Patents

Abstract

The invention relates to the technical field of vibration sensors, in particular to a structure of a three-axis vibration sensor, and aims to solve the problems that the existing three-axis vibration sensor is prone to high-frequency resonance, susceptible to electromagnetic interference and relatively large in size. It is characterized in that it includes a fixing device, a signal transmission device and a measuring device; the measuring device is fixedly connected inside the fixing device; the signal transmission device penetrates from the outside of the fixing device into the inside of the fixing device, and is fixedly connected with the fixing device; the signal transmission device is also connected with the fixing device The measuring device is connected; the measuring device is used to measure the acceleration of the object to be measured; the fixing device is used to provide support and protection for the measuring device and the signal transmission device; the signal transmission device is used to transmit the acceleration signal measured by the measuring device to the signal acquisition device. The invention adopts the integrated design of four rigid printed boards and three flexible boards, realizes the reliable connection of the interface, saves the internal space of the sensor, greatly improves the frequency response, and obviously reduces the signal noise.

Description

A three-axis vibration sensor structure

technical field

The invention relates to the technical field of vibration sensors, in particular to a three-axis vibration sensor structure.

Background technique

The three-axis vibration sensor can simultaneously measure vibration signals in three directions of X, Y, and Z that are orthogonal to each other at a measuring point, and has broad application prospects in the aerospace field.

The frequency response characteristic is one of the most important indicators to measure the performance of the vibration sensor. Although the traditional three-axis piezoresistive vibration sensor has a good DC effect, its temperature effect is serious, the dynamic range is limited, and the frequency response characteristic can only reach 1KHz. about. The three-axis capacitive vibration sensor has the advantages of high sensitivity, low temperature effect, and low power consumption. However, due to the high impedance of the sensor output, it is easily affected by electromagnetic interference and is not suitable for working in harsh environments. And its frequency range is limited, the highest is about 3KHz. The three-axis piezoelectric vibration sensor has a wide frequency range and good linearity, but due to charge leakage, it is prone to charge blocking effect, and the three-axis piezoelectric vibration sensor generally adopts a separate structure design of the sensor and the converter, which is not easy to achieve integration .

There are some deficiencies in the above-mentioned vibration sensors, which seriously limit the application range of the sensors.

Contents of the invention

The purpose of the present invention is to solve the problems that the existing triaxial vibration sensor is prone to high-frequency resonance, susceptible to electromagnetic interference and large in size, and provides a sensor with high frequency response characteristics, strong anti-interference ability, high connection reliability and Compact triaxial vibration sensor structure.

The present invention is achieved like this:

A three-axis vibration sensor structure, including a fixing device, a signal transmission device and a measuring device; the measuring device is fixedly connected inside the fixing device; the signal transmission device penetrates from the outside of the fixing device to the inside of the fixing device, and is fixedly connected with the fixing device; The transmission device is also connected with the measurement device; the measurement device is used to measure the acceleration of the object to be measured; the fixing device is used to provide support and protection for the measurement device and the signal transmission device; the signal transmission device is used to transmit the acceleration signal measured by the measurement device to Signal acquisition equipment.

The above-mentioned fixing device includes a housing, a wire harness, a wire screw, a nut, a washer and a top cover; the housing as a whole is a hollow cuboid with an open upper end; There are two fixed through holes in the height direction of the body; a through hole is opened on the rear end surface of the rectangular parallelepiped of the shell; There are two through holes in the corresponding position, and the two through holes are matched with the fixed through holes of the shell respectively, and are used to fix the vibration sensor structure on the object to be measured; The outer diameter of the upper cylinder is larger than the outer diameter of the lower cylinder, the inner diameter of the upper cylinder is larger than the inner diameter of the lower cylinder, and the outer diameter of the upper cylinder is larger than that of the through hole on the rear surface of the rectangular parallelepiped shell. diameter, the outer diameter of the lower end cylinder is less than or equal to the diameter of the through hole on the cuboid rear end face of the shell; the front end of the upper end cylinder is provided with a through hole, and the inner surface of the through hole has an internal thread; the outer surface of the lower end cylinder has an outer thread. Thread; the upper cylinder is located inside the housing, and the lower cylinder passes through the through hole on the rectangular rear end surface of the housing; the nut is threaded with the lower cylinder of the harness tube; the nut is used to fix the harness tube on the housing; The gasket is a circular ring as a whole, and there is a gap on the ring, and the outer diameter of the ring is less than or equal to the inner diameter of the upper end cylinder of the harness tube; The through holes at the front end of the cylinder are staggered; the wire harness screw is an M3 type screw with a notch on the upper end surface along the diameter direction; contact with the outer surface of the gasket.

The above-mentioned housing, harness tube, harness screw, nut and top cover are all made of aluminum alloy material; the gasket is made of soft aluminum material; the thickness of the housing is 1.5mm; the total of the housing and the top cover The size is 27×27×21mm.

The above-mentioned signal transmission device includes a wire, a cable and an electrical connector; one end of the wire is connected to the measuring device, and the other end is connected to one end of the cable; the other end of the cable is connected to one end of the electrical connector; the other end of the electrical connector Connects to signal acquisition equipment; the wires pass through the inside of the harness tube of the fixture while passing through the inside of the gasket.

The measuring device as described above includes a rigid-flexible circuit board and a sensitive core; the rigid-flexible circuit board includes a first rigid board, a second rigid board, a third rigid board, a fourth rigid board, a first flexible board, a first Two flexible boards and the third flexible board; the first rigid board is connected with the third rigid board through the second flexible board; the second rigid board is connected with the third rigid board through the first flexible board; the third rigid board is connected with the third rigid board through the second flexible board; The fourth rigid board is connected through the third flexible board; the first rigid board, the second rigid board, the third rigid board and the fourth rigid board all adopt a four-layer board structure, which is a signal layer, two The inner signal layer and the bottom layer; the signal layer is used for soldering components, the inner signal layer is used for wiring, and the bottom layer is used for connection and insulation isolation with the housing of the fixture; the first flexible board, the second flexible board and the third The flexible board adopts a double-layer board structure, and the wiring between the two boards; there are three sensitive cores, which are respectively welded on the signal layers of the first rigid board, the second rigid board and the third rigid board; The power supply terminal is connected to the voltage regulator on the rigid board, and the output terminal of the sensitive core is connected to the front end of the conversion circuit on the rigid board; the first rigid board is fixed on the right inner wall of the housing, and the second rigid board is fixed on the housing The fourth rigid plate is fixed on the left inner wall of the housing, and the third rigid plate is fixed on the lower inner wall of the housing; the wires of the signal transmission device are respectively connected to the first rigid plate and the second rigid plate , The signal layers of the third rigid board and the fourth rigid board are soldered.

The first rigid board, the second rigid board, the third rigid board and the fourth rigid board are all made of epoxy glass cloth pressing board; the first flexible board, the second flexible board and the third flexible board All made of polyimide material.

The circuit connection relationship of the rigid-flex circuit board mentioned above is determined according to GJB362B-2009, and the sensitive core is realized by the 1221 core produced by SDI company.

The beneficial effects of the present invention are:

The invention includes a fixing device, a signal transmission device and a measuring device. Through the integrated design of four rigid printed boards and three flexible boards, the reliable connection of the interface is realized, the internal space of the sensor is saved, and the signal noise during signal transmission is significantly reduced. 5 prototypes were produced by applying the invention, and the performance index was verified on the vibration sensor calibration system. Under the condition that the in-band unevenness is less than 1dB, the frequency response characteristics of the sensors can all reach 5KHz. After the integrated design, the filter function and voltage adjustment circuit function of the five prototypes all work normally, and the sensitivity in three directions and the noise dry value in the final output signal all meet the requirements of the test.

Description of drawings

Fig. 1 is the front sectional view of a kind of triaxial vibration sensor structure of the present invention;

Fig. 2 is the A-A cut-away view of a kind of triaxial vibration sensor structure of the present invention;

Fig. 3 is a front sectional view of a harness tube in a triaxial vibration sensor structure of the present invention;

Fig. 4 is the A-A sectional view of the harness tube in a kind of triaxial vibration sensor structure of the present invention;

Fig. 5 is the front view of the washer in a kind of triaxial vibration sensor structure of the present invention;

Fig. 6 is a top view of a gasket in a triaxial vibration sensor structure of the present invention;

Fig. 7 is a structural schematic diagram of a rigid-flexible circuit board in a triaxial vibration sensor structure of the present invention.

Among them: 1. Shell, 2. Rigid-flexible circuit board, 3. Wire, 4. Sensitive core, 5. Harness tube, 6. Beam screw, 7. Nut, 8. Cable, 9. Electrical connector , 10. Gasket, 11. Top cover, 12. Rigid plate, 12-1. First rigid plate, 12-2. Second rigid plate, 12-3. Third rigid plate, 12-4. Fourth rigid plate , 13. Flexible board, 13-1. First flexible board, 13-2. Second flexible board, 13-3. Third flexible board.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

A three-axis vibration sensor structure includes a fixing device, a signal transmission device and a measuring device. The measuring device is fixedly connected inside the fixture. The signal transmission device penetrates from the outside of the fixing device to the inside of the fixing device, and is fixedly connected with the fixing device. The signal transmission device is also connected to the measuring device. The measuring device is used to measure the acceleration of the object to be measured. Fixtures are used to support and protect measuring devices and signal transmission devices. The signal transmission device is used to transmit the acceleration signal measured by the measuring device to the signal acquisition device.

As shown in FIG. 1 and FIG. 2 , the fixing device includes a housing 1 , a harness tube 5 , a harness screw 6 , a nut 7 , a washer 10 and a top cover 11 . The casing 1 is in the shape of a hollow cuboid with an open upper end as a whole. Two fixing through holes are opened along the height direction of the housing 1 on two opposite corners of the rectangular parallelepiped of the housing 1 . A through hole is provided on the rectangular parallelepiped rear end surface of the housing 1 . The top cover 11 is in the shape of a square plate as a whole, and covers the upper surface of the housing 1 . The top cover 11 is provided with two through holes corresponding to the fixing through holes of the housing 1, and the two through holes are respectively matched with the fixing through holes of the housing 1 to fix the vibration sensor structure on the object to be measured. As shown in Fig. 3 and Fig. 4, the harness tube 5 is in the shape of a "T" as a whole, consisting of two hollow cylinders up and down, the outer diameter of the upper cylinder is greater than the outer diameter of the lower cylinder, and the inner diameter of the upper cylinder is greater than that of the lower cylinder. The inner diameter of the lower end cylinder and the outer diameter of the upper end cylinder are greater than the diameter of the through hole on the cuboid rear end surface of the housing 1, and the outer diameter of the lower end cylinder is less than or equal to the diameter of the through hole on the cuboid rear end surface of the housing 1. A through hole is opened on the front end of the upper cylinder, and the inner surface of the through hole is provided with internal threads. The outer surface of the cylinder at the lower end has external threads. The upper cylinder is located inside the housing 1, and the lower cylinder passes through a through hole on the cuboid rear end surface of the housing 1. The nut 7 is threadedly connected with the cylinder at the lower end of the harness tube 5 . The nut 7 is used to fix the harness tube 5 on the housing 1 . As shown in FIG. 5 and FIG. 6 , the gasket 10 is in the shape of a ring as a whole, and there is a gap on the ring, and the outer diameter of the ring is smaller than or equal to the inner diameter of the upper cylinder of the harness tube 5 . Gasket 10 is installed in the inside of the cylinder at the upper end of the wire harness 5 , and the ring gap of the gasket 10 is staggered with the through hole at the front end of the cylinder at the upper end of the wire harness 5 . The wire harness screw 6 is an M3 type screw with a notch on the upper end surface along the diameter direction. The wire harness screw 6 is threadedly connected with the through hole provided on the front end of the upper cylinder of the wire harness tube 5 , and the tip of the wire harness screw 6 is in contact with the outer surface of the washer 10 .

In this embodiment, the casing 1 , the harness tube 5 , the harness screw 6 , the nut 7 , the washer 10 and the top cover 11 are all made of aluminum alloy. The thickness of the casing 1 is 1.5 mm. The total size of the housing 1 and the top cover 11 is 27×27×21 mm.

As shown in FIG. 2 , the signal transmission device includes wires 3 , cables 8 and electrical connectors 9 . One end of the wire 3 is connected to the measuring device, and the other end is connected to one end of the cable 8 . The other end of the cable 8 is connected to one end of the electrical connector. The other end of the electrical connector is connected with the signal acquisition device. The wire 3 passes through the inside of the harness tube 5 of the fixing device, and at the same time passes through the inside of the gasket 10 .

In this embodiment, the wire 3, the cable 8 and the electrical connector 9 are all general-purpose components and can be purchased from the market.

As shown in FIG. 7 , the measuring device includes a rigid-flex circuit board 2 and a sensitive core 4 . The rigid-flex circuit board 2 includes a first rigid board 12-1, a second rigid board 12-2, a third rigid board 12-3, a fourth rigid board 12-4, a first flexible board 13-1, a second The flexible board 13-2 and the third flexible board 13-3. The first rigid board 12-1 is connected to the third rigid board 12-3 through the second flexible board 13-2. The second rigid board 12-2 is connected to the third rigid board 12-3 through the first flexible board 13-1. The third rigid board 12-3 is connected to the fourth rigid board 12-4 through the third flexible board 13-3. The first rigid board 12-1, the second rigid board 12-2, the third rigid board 12-3 and the fourth rigid board 12-4 all adopt a four-layer board structure, which is a signal layer, two layer internal signal layer and bottom layer. The signal layer is used for soldering components, the internal signal layer is used for wiring, and the bottom layer is used for connection and isolation with the housing 1 of the fixing device. The first rigid board 12-1, the second rigid board 12-2, the third rigid board 12-3 and the fourth rigid board 12-4 are all made of epoxy glass cloth press board. The first flexible board 13 - 1 , the second flexible board 13 - 2 and the third flexible board 13 - 3 all adopt a double-layer board structure, with wiring between the two-layer boards. The first flexible board 13-1, the second flexible board 13-2 and the third flexible board 13-3 are all made of polyimide material. There are three sensitive cores 4, which are respectively welded on the signal layers of the first rigid board 12-1, the second rigid board 12-2 and the third rigid board 12-3. The power supply end of the sensitive core 4 is connected to the voltage regulator on the rigid board 12 , and the output end of the sensitive core 4 is connected to the front end of the conversion circuit on the rigid board 12 . The first rigid plate 12-1 is fixed on the right inner wall of the housing 1, the second rigid plate 12-2 is fixed on the front inner wall of the housing 1, and the fourth rigid plate 12-4 is fixed on the left side of the housing 1. On the side inner wall, the third rigid board 12 - 3 is fixed on the lower side inner wall of the housing 1 . The wires 3 of the signal transmission device are respectively welded to the signal layers of the first rigid board 12 - 1 , the second rigid board 12 - 2 , the third rigid board 12 - 3 and the fourth rigid board 12 - 4 .

In this embodiment, the circuit connection relationship of the rigid-flexible circuit board 2 is determined according to GJB362B-2009, and the sensitive core 4 is realized by the 1221 core produced by SDI Company.

Before the test, the rigid-flex circuit boards 2 are bonded to the four inner surfaces of the casing 1, and the three rigid boards 12 welded with the sensitive core 4 are arranged in an orthogonal manner. Then the wire 3 connected to the cable 8 is penetrated into the interior of the housing 1 through the through hole on the rear end surface of the housing 1, the wire harness tube 5 and the washer 10 are passed on the cable 8, and the tip of the wire harness screw 6 is pressed against the washer 10. Then the wire 3 connected to the cable 8 is welded to the rigid plate 12 , and the wire harness 5 is fixed on the housing 1 with the nut 7 . Finally, the top cover 11 is bonded to the upper surface of the housing 1, and the sensor structure assembly is completed.

During the test, the sensor structure is fixed on the measured surface of the object to be measured by two M3 screws to measure the acceleration of the object to be measured in three directions. The measured results are output to the signal acquisition device through the wire 3 , the cable 8 and the electrical connector 9 .

The invention includes a fixing device, a signal transmission device and a measuring device. Through the integrated design of four rigid printed boards and three flexible boards, the reliable connection of the interface is realized, the internal space of the sensor is saved, and the signal noise during signal transmission is significantly reduced. 5 prototypes were produced by applying the invention, and the performance index was verified on the vibration sensor calibration system. Under the condition that the in-band unevenness is less than 1dB, the frequency response characteristics of the sensors can all reach 5KHz. After the integrated design, the filter function and voltage adjustment circuit function of the five prototypes all work normally, and the sensitivity in three directions and the noise dry value in the final output signal all meet the requirements of the test.

Claims (7)

1. a three-axial vibration sensor construction, is characterized in that: it comprises fixture, signal transmission dressPut and measurement mechanism; Measurement mechanism is fixedly connected on fixture inside; Signal transmitting apparatus is from fixtureOutside penetrates into fixture inside, is fixedly connected with fixture; Signal transmitting apparatus also with measurement mechanismConnect; Measurement mechanism is for measuring the acceleration of object under test; Fixture is used for measurement mechanism and signalTransmitting device provides support and protects; Signal transmitting apparatus passes for the acceleration signal that measurement mechanism is recordedBe defeated by signal collecting device.

2. three-axial vibration sensor construction according to claim 1, is characterized in that: described is fixingDevice comprises housing (1), bunch pipe (5), bunch screw (6), nut (7), packing ring (10) and topLid (11); Housing (1) entirety is the cuboid of the hollow of upper end open; At housing (1) cuboidOn two relative angles, have two fixed vias along housing (1) short transverse; At housing (1) cuboidOn shape rear end face, have through hole; Top cover (11) entirety is that square is tabular, covers the upper end in housing (1)On face; Top cover (11) has two through holes with housing (1) fixed via correspondence position, and two through holes respectivelyMatch with the fixed via of housing (1), for vibrating sensor structure is fixed on to object under test; BundleSpool (5) entirety is "T"-shaped, is made up of the cylindrical external diameter in upper end the cylinder of upper and lower two hollowsBe greater than the cylindrical external diameter in lower end, the cylindrical internal diameter in upper end is greater than the cylindrical internal diameter in lower end, upper end cylinderThe external diameter of body is greater than the diameter of through hole on housing (1) cuboid rear end face, and the cylindrical external diameter in lower end is less thanEqual the diameter of through hole on housing (1) cuboid rear end face; In upper end, cylindrical front end has through hole,This through-hole inner surface has internal thread; The cylindrical outer surface in lower end has external screw thread; Upper end cylinder is positioned at housing(1) inside, cylinder through hole from housing (1) cuboid rear end face in lower end passes; Nut (7) withBunch pipe (5) lower end cylinder is threaded; Nut (7) is for being fixed on housing (1) by bunch pipe (5)On; Packing ring (10) entirety is annular, has breach on annulus, and annulus external diameter is less than or equal to bunch pipe (5)The cylindrical internal diameter in upper end; Packing ring (10) is arranged on cylindrical inside, bunch pipe (5) upper end, packing ring (10)The through hole of annulus breach and bunch pipe (5) upper end cylinder front end staggers; Bunch screw (6) is upper surfaceHave the M3 type screw of gap along diametric(al); Bunch screw (6) is cylindrical with bunch pipe (5) upper endThe through hole whorl that front end has connects, and the tip of bunch screw (6) contacts with the outer surface of packing ring (10).

3. three-axial vibration sensor construction according to claim 2, is characterized in that: described housing(1), bunch pipe (5), bunch screw (6), nut (7) and top cover (11) all adopt aluminum alloy materialsMake; Packing ring (10) adopts soft aluminum to make; The thickness of housing (1) is 1.5mm; Housing (1)And the overall size of top cover (11) is 27 × 27 × 21mm.

4. three-axial vibration sensor construction according to claim 1, is characterized in that: described signalTransmitting device comprises wire (3), cable (8) and electric connector (9); One end and the measurement of wire (3)Device connects, and the other end is connected with the one end of cable (8); The other end of cable (8) and electric connectorOne end connects; The other end of electric connector is connected with signal collecting device; Wire (3) is from the bundle of fixtureThe inside of spool (5) is passed, and passes the inside of packing ring (10) simultaneously.

5. three-axial vibration sensor construction according to claim 1, is characterized in that: described measurementDevice comprises rigid-flexible combined circuit plate (2) and sensitive core body (4); Rigid-flexible combined circuit plate (2) comprisesOne rigid plate (12-1), the second rigid plate (12-2), the 3rd rigid plate (12-3), the 4th rigid plate (12-4),The first flex plate (13-1), the second flex plate (13-2) and the 3rd flex plate (13-3); The first rigid plate (12-1)Be connected by the second flex plate (13-2) with the 3rd rigid plate (12-3); The second rigid plate (12-2) and theThree rigid plate (12-3) connect by the first flex plate (13-1); The 3rd rigid plate (12-3) is firm with the 4thProperty plate (12-4) by the 3rd flex plate (13-3) connect; The first rigid plate (12-1), the second rigid plate(12-2), the 3rd rigid plate (12-3) and the 4th rigid plate (12-4) all adopt four-sheet structure, by upperExtremely, be followed successively by one deck signals layer, two-layer internal signal layer and bottom; Signals layer is used for welding component, inPortion's signals layer is for wiring, and bottom is for being connected and the isolation of insulating with the housing (1) of fixture; First scratchesProperty plate (13-1), the second flex plate (13-2) and the 3rd flex plate (13-3) all adopt double panel structure,Between two-ply, connect up; Sensitive core body (4) has three, is welded on respectively the first rigid plate (12-1),On the signals layer of two rigid plate (12-2) and the 3rd rigid plate (12-3); The power end of sensitive core body (4)Be connected the output of sensitive core body (4) and rigid plate (12) with the voltage adjuster in rigid plate (12)The front end of up conversion circuit connects; The first rigid plate (12-1) is fixed on the right side inwall of housing (1),The second rigid plate (12-2) is fixed on the front side inwall of housing (1), and the 4th rigid plate (12-4) is fixingIn the inner left wall of housing (1), the 3rd rigid plate (12-3) is fixed on the downside inwall of housing (1);The wire (3) of signal transmitting apparatus respectively with the first rigid plate (12-1), the second rigid plate (12-2),The signals layer welding of three rigid plate (12-3) and the 4th rigid plate (12-4).

6. three-axial vibration sensor construction according to claim 5, is characterized in that: described firstRigid plate (12-1), the second rigid plate (12-2), the 3rd rigid plate (12-3) and the 4th rigid plate (12-4)All adopt epoxy glass fabric pressing plate to make; The first flex plate (13-1), the second flex plate (13-2) and the 3rdFlex plate (13-3) all adopts polyimide material to make.

7. three-axial vibration sensor construction according to claim 5, is characterized in that: described is rigid-flexibleThe circuit connecting relation of combined circuit plate (2) is determined according to GJB362B-2009, sensitive core body (4) employing1221 core bodies that SDI company produces are realized.