JP6770744B2 - Vibration sensor - Google Patents

Description

The present invention relates to a vibration sensor that can be particularly suitably used for applications such as bearing abnormality detection.

A vibration sensor for a sphygmomanometer using an electret condenser microphone has been proposed (Patent Document 1).

In a conventional vibration sensor, an electlet condenser microphone is incorporated in a case having an opening at the bottom, a vibration transmission member is attached to the outer surface of the bottom of the case via a cushioning material, and a vibration transmission member is attached to the center of the vibration transmission member through the opening of the case. It is configured by contacting the protruding portion of the portion with the diaphragm of the electrette condenser microphone. By incorporating the vibration sensor into the cuff (arm band for pressurization) of the blood pressure monitor, it is possible to efficiently detect low-frequency heartbeat sounds (Korotkoff sounds) from blood vessels.

Japanese Unexamined Patent Publication No. 2011-10913

According to the conventional technique, since the vibration transmission member senses the low-frequency air vibration generated inside the cuff by the heartbeat sound, the pressure receiving area is increased and the electlet condenser microphone is operated through a soft cushioning material. It needs to be mounted on a case, for example, when it is used for detecting internal abnormalities of mechanical parts such as bearings, pinpoint measurement is difficult, the measurement frequency range is narrow, and high frequency range cannot be detected. There was a problem.

Therefore, an object of the present invention is, in view of the problem of the prior art, vibration that can be suitably applied to applications such as bearing abnormality detection by mounting a microphone on the base of a detection member that forms a detection portion at the tip portion. It is to provide a sensor.

The configuration of the present invention for achieving such an object is a detection member having a sharpened tip to form a detection portion, a microphone attached to the base of the detection member, and an elastic cover body for accommodating the detection member together with the microphone. The gist is that when the detection unit is pressed against an object, a part of the cover body hanging around the detection unit elastically deforms to shield the detection unit from external noise.

A casing for accommodating the cover body can be attached so that the lower end portion of the cover body protrudes from the lower end portion of the casing.

Further, the casing may be configured so as to be fixed to the object.

Further, a foundation case that holds the casing so as to be slidable up and down, a main body case that is connected above the foundation case, and an urging member that urges the casing downward are added, and the lower end portion of the cover body is added. May be projected onto the lower surface of the base case, the circuit board may be held in the main body case, one or more auxiliary cases are connected above the main body case, and each auxiliary case has a circuit. The substrate may be held.

According to the configuration of the present invention, the detection member can transmit the vibration sound originating from the inside of the object to the microphone at the base by pressing the detection unit against the object. On the other hand, the cover body of the elastic body houses the detection member integrated with the microphone, and when the detection unit is pressed against the object, the portion hanging around the detection unit is elastically deformed to shield the detection unit from external noise. However, the entire detection member and microphone can be effectively shielded to minimize harmful noise from the outside. The detection member efficiently transmits vibration sound in a predetermined band including a high frequency region to the microphone, and the detection unit formed by sharpening the tip of the detection member has a small contact area with an object and is pinpoint. It can be measured and is suitable for detecting internal abnormalities of mechanical parts such as bearings. Further, by using an electret condenser microphone as the microphone, the frequency characteristics are good, the detection sensitivity in the high frequency range is high, a bias power supply is not required, and the size and weight can be easily reduced.

The casing for accommodating the cover body limits the elastic deformation range of the cover body to the lower end portion protruding to the outside and mechanically protects the cover body. However, when the casing is used as a fixing member for fixing the whole object to the object, for example, a male screw for fixing may be formed on the outer surface, or a leg for fixing may be attached.

When adding the foundation case, main body case, and urging member, use the foundation case to install the whole on the surface of the object, and elastically deform the lower end of the cover body protruding from the lower surface of the foundation case to detect the detection unit. Can be pressed against the object and the pressing force applied to the detection unit via the urging member can be regulated to a predetermined appropriate size. The urging member urges the casing downward and urges the detection member downward through the cover body in the casing, thereby elastically deforming a part of the cover body protruding from the lower surface of the base case. This is because the detection unit can be pressed against the object. The urging member is interposed between the casing inside the foundation case and the main body case connected above the foundation case to urge the casing, the cover body inside the casing, and the detection member downward. can do.

The circuit board held in the main body case can be configured as, for example, a connection board for connecting and processing the lead wire from the microphone. However, the lead wire from the microphone can be pulled out directly from above the main body case without using a circuit board.

The circuit board held in each of one or more auxiliary cases connected above the main body case can be equipped with electronic circuit components necessary for appropriately processing the output signal from the microphone. Examples of these electronic circuit components include amplifiers and A / D converter elements for analog signal processing, microcomputer elements having frequency analysis functions and communication control functions, communication module elements for external communication, and power supplies. Such as the battery of.

Overall schematic perspective view Overall schematic vertical sectional view Usage state explanatory diagram Schematic perspective view showing another embodiment Schematic explanatory view showing another embodiment Explanatory perspective view showing another embodiment Central vertical sectional view of FIG. Schematic exploded perspective view of FIG. An exploded perspective view of a main part showing another embodiment

Hereinafter, embodiments of the invention will be described with reference to the drawings.

The vibration sensor is formed by integrally assembling the detection member 11, the microphone 12, the cover body 13, and the casing 14 (FIGS. 1 and 2).

The detection member 11 is formed of a rigid material such as a metal material, a hard plastic material, or a ceramic material, as well as a resin material such as rubber having a hardness of about 50 to 90 Hs (JIS A) or silicone rubber. The detection member 11 is formed with a conical trapezoidal downward detection portion 11a having a small-diameter top surface with an obliquely pointed tip, and a recess 11b to be mounted so as to embed the microphone 12 is formed at the base portion. There is. The detection portion 11a and the recess 11b are formed coaxially at the lower end portion and the upper end portion of the cylindrical detection member 11, respectively.

The microphone 12 is mounted in the recess 11b of the detection member 11 so as to detect the vibration sound transmitted through the detection member 11. The microphone 12 is preferably an electret condenser microphone, but may be another condenser microphone, a dynamic microphone, a velocity microphone, or the like. The output of the microphone 12 is drawn out to the terminal box 12b via the lead wires 12a and 12a.

The cover body 13 is formed in a covered cylindrical shape having an inner diameter that matches the outer diameter of the detection member 11 and is open at the bottom, and can accommodate the detection member 11 integrated with the microphone 12. The cover body 13 covers the outer surface of the detection member 11 and the microphone 12 excluding the detection unit 11a, and the lower end portion of the cover body 13 is longer than the detection unit 11a of the detection member 11 and hangs like a skirt around the detection unit 11a. are doing. The lead wires 12a and 12a of the microphone 12 penetrate the lid portion at the upper end of the cover body 13 and are pulled out to the outside. The cover body 13 is integrally molded with an elastic body such as a silicone resin.

The casing 14 is formed in a cylindrical shape with both ends open so that the cover body 13 for accommodating the detection member 11 and the microphone 12 can be accommodated in the axial direction. A terminal box 12b for the microphone 12 is fixed to the upper end of the outer surface of the casing 14. As for the lower end portion of the cover body 13, a portion below the range substantially corresponding to the detection portion 11a of the detection member 11 projects from the lower end portion of the casing 14 and is exposed to the outside.

In such a vibration sensor, when the detection unit 11a of the detection member 11 is pressed against the surface of the object D such as a bearing of a mechanical part (FIG. 3), a part of the cover body 13 hanging around the detection unit 11a is elastic. It is deformed and effectively shields the detection unit 11a from external noise. Therefore, the detection member 11 transmits the vibration sound originating from the inside of the object D to the microphone 12, and the microphone 12 detects the internal abnormality of the object D by detecting the vibration sound from the object D. can do. The output signal of the microphone 12 can be input to a computer for analysis via an appropriate amplifier, bandpass filter, or the like (not shown) to construct a monitoring system for the object D. However, FIG. 3 schematically shows only a part of the outer case of the object D.

Other embodiments

The vibration sensor can form a male screw 14a for mounting on the outer surface of the casing 14 (FIG. 4). On the other hand, the object D can be formed with a bottomed mounting hole D1 having a female screw D1a that matches the male screw 14a, and the casing 14 can be screwed into the mounting hole D1 to fix the vibration sensor to the object D. However, in the mounting hole D1, the detection portion 11a of the detection member 11 reaches and contacts the bottom of the mounting hole D1, and the cover body 13 protruding from the lower end of the casing 14 is elastically deformed and stored inside the mounting hole D1. It shall be set to an appropriate size so that it will be.

Further, the vibration sensor may have legs 14b, 14b for fixing attached to the lower outer surface of the casing 14 (FIG. 5). However, FIGS. 5A and 5B are an overall schematic perspective view and a schematic vertical sectional view, respectively.

A round hole 14b1 for mounting is formed in each leg 14b. Therefore, by screwing each leg 14b to the surface of the object D (not shown), the detection portion 11a of the detection member 11 is pressed against the object D, and the lower end portion of the cover body 13 is elastically deformed to perform the operation shown in FIG. The form can be easily realized. However, the height, mounting position, etc. of each leg 14b shall be appropriately set.

The vibration sensor can be combined with the basic case 21, the main body case 22, the auxiliary cases 23, 23, and so on, which are connected so as to be stacked from the bottom to the top (FIGS. 6 and 7). However, FIGS. 6A and 6B are schematic perspective views of the upper surface side and the lower surface side, respectively.

In FIG. 7, the detection member 11 of the vibration sensor is formed with a downward detection portion 11a having an obtuse apex angle with respect to a short cylindrical material substantially corresponding to the thickness of the microphone 12. Further, the elastic cover body 13 has a skirt portion 13b that hangs around the detection portion 11a by forming a downward recess 13a having an inner diameter larger than the outer diameter of the detection member 11. An annular notch 13c that diagonally expands above the detection portion 11a is formed on the upper edge of the recess 13a.

The casing 14 is formed in a covered cylindrical shape having a top plate 14c at the upper end (FIGS. 7 and 8). Through holes 14d, 14d ... Are formed in the top plate 14c, and a guide cylinder 14e is erected in the central portion of the top plate 14c so as to penetrate the top plate 14c. The cover body 13 is housed in the casing 14 together with the detection member 11 and the microphone 12 so as to reach the lower surface of the top plate 14c. However, the outer diameter of the lower end portion of the cover body 13 protruding from the lower end of the casing 14 (the portion below the alternate long and short dash line 13d on the cover body 13 in FIG. 8) gradually decreases downward, and the inner diameter of the recess 13a is , Gradually increasing downwards. Therefore, the skirt portion 13b around the detection portion 11a is linearly thinned downward.

The foundation case 21 is formed by erecting a stepped tubular portion 21b on a square mounting flange 21a. The outer diameter of the tubular portion 21b is formed so that the upper half and the lower half have a small diameter and a large diameter, respectively, and the inner diameter conforms to the outer diameter of the casing 14. Further, at the lower end of the tubular portion 21b, a round hole 21c corresponding to the inner diameter of the casing 14 is formed so as to penetrate the mounting flange 21a. Therefore, the base case 21 can be held in the tubular portion 21b so as to be slidable up and down with the casing 14 facing downward. Further, the lower end of the cover body 13 protruding from the lower end of the casing 14 protrudes to the lower surface of the base case 21 through the round hole 21c, and the top of the detection portion 11a in the skirt portion 13b of the cover body 13 is the base case 21. It is located below the bottom surface of.

The main body case 22 has a partition plate 22b on the inner upper side of the cylindrical body 22a. The inner diameter of the cylindrical body 22a conforms to the outer diameter of the small diameter portion of the upper half of the tubular portion 21b of the base case 21, and the outer diameter matches the outer diameter of the large diameter portion of the lower half of the tubular portion 21b. There is. Small-diameter and large-diameter guide cylinders 22c and 22d are formed concentrically upward and downward at the center of the partition plate 22b, and the guide cylinder 14e of the casing 14 is a small-diameter guide penetrating the partition plate 22b. It is slidably inserted into the cylinder 22c. Further, a coil spring 24 as an urging member for urging the casing 14 downward is mounted on the guide cylinder 14e, and the coil spring 24 is interposed between the top plate 14c and the partition plate 22b.

A pair of engaging grooves 21d and 21d for connection are formed on the outer surface of the small diameter portion of the upper half of the tubular portion 21b of the base case 21. Each engaging groove 21d is opened upward and the lower end is bent horizontally. On the other hand, a pair of inward engaging protrusions 22e and 22e corresponding to the engaging grooves 21d and 21d of the base case 21 are formed at the lower end of the inner surface of the cylindrical body 22a of the main body case 22. However, in FIG. 7, only one engaging protrusion 22e is shown.

In the main body case 22, the small diameter portion of the upper half of the tubular portion 21b of the base case 21 is inserted from the lower end of the cylindrical body 22a so that the engaging protrusions 22e and 22e are aligned with the engaging grooves 21d and 21d. By rotating the 21d and 21d horizontally by a predetermined angle in the bending direction, the base case 21 can be connected above the base case 21. On the outer surface of the large-diameter portion of the tubular portion 21b of the base case 21, alignment marks 21e and 21e1 indicating the positions of the engaging grooves 21d and the positions where the main body case 22 is completed are displayed (FIG. 6 (A)). 8), At the lower end of the outer surface of the main body case 22, a matching mark 22f indicating the position of each engaging protrusion 22e is displayed.

A donut plate-shaped circuit board 31 is housed on the partition plate 22b of the main body case 22 (FIGS. 7 and 8). A guide cylinder 22c penetrates from the bottom to the top in the center of the circuit board 31, and an upward connector 33 is mounted on the circuit board 31 in addition to the predetermined electronic circuit parts 32 and 32.

A pair of engaging grooves 22g and 22g for connecting the auxiliary case 23 are formed at the upper end of the inner surface of the main body case 22. Each engaging groove 22g is opened upward and the lower end is bent horizontally, similarly to the engaging groove 21d of the base case 21. Further, on the upper end of the outer surface of the main body case 22, alignment marks 22h and 22h1 indicating the positions of the engaging grooves 22g and the positions where the auxiliary cases 23 have been connected are displayed (FIGS. 6 and 8).

In each auxiliary case 23, ring-shaped thin-walled portions 23a and 23b are formed by cutting out the upper end portion of the inner surface and the lower end portion of the outer surface of a short cylindrical member in a strip shape, respectively (FIGS. 7 and 8). A pair of engaging grooves 23c and 23c for connecting other auxiliary cases 23 similar to the engaging grooves 22g and 22g of the main body case 22 are formed on the inner surface of the upper thin-walled portion 23a, and the lower thin-walled portion 23b On the outer surface, a pair of outward engaging protrusions 23d and 23d similar to the engaging protrusions 22e and 22e of the main body case 22 are formed. However, in FIGS. 7 and 8, only one engaging protrusion 23d is shown for each auxiliary case 23. The outer diameter of the auxiliary case 23 is the same as the outer diameter of the main body case 22, and the outer diameter of the lower thin-walled portion 23b is the inner diameter of the main body case 22 and the inner diameter of the upper thin-walled portion 23a of the other auxiliary case 23. Fits to. Further, on the upper end of the outer surface of the auxiliary case 23, alignment marks 23e and 23e1 indicating the positions of the engaging grooves 23c and the positions where the other auxiliary cases 23 have been connected are displayed (FIGS. 6 and 8). At the lower end of the outer surface, a matching mark 23f indicating the position of each engaging protrusion 23d is displayed.

Therefore, the engaging protrusions 23d and 23d of the auxiliary case 23 can be engaged with the engaging grooves 22g and 22g of the main body case 22, and the auxiliary case 23 can be connected above the main body case 22 (FIGS. 7 and 8). ). However, the mode of connecting the two is the same as the mode of connecting the main body case 22 to the basic case 21. When the auxiliary case 23 is connected to the main body case 22, the entire circumference of the circuit board 31 in the main body case 22 is pressed by the lower end of the auxiliary case 23, and the circuit board 31 is stably held in the main body case 22.

On the other hand, when the engaging protrusions 23d, 23d of the other auxiliary case 23 are engaged with the engaging grooves 23c, 23c of the auxiliary case 23, the auxiliary cases 23, 23 ... Are connected in this order from bottom to top. be able to. Further, a circular circuit board 41 can be housed in each auxiliary case 23. On the circuit board 41, in addition to the predetermined electronic circuit components 42, 42 ..., The downward and upward connectors 43, 44 are mounted at symmetrical positions. Therefore, each circuit board 41 connects the downward connector 43 to the upward connector 33 on the lower circuit board 31 or the upward connector 43 on the other circuit board 41 below, and is above the auxiliary case 23. It is stably held in the auxiliary case 23 via another auxiliary case 23 to be connected. However, the circuit board 41 in the uppermost auxiliary case 23 is fixed via, for example, a lid member (not shown). The circuit board 31 in the main body case 22 is used for connection processing of lead wires (not shown) from the microphone 12, and the circuit boards 41, 41 ... In each auxiliary case 23 are used in order from bottom to top, for example, the microphone 12. It can be used for amplification processing of the output signal of the above, for computer processing such as frequency analysis of the signal, for an external communication module, and for a battery for the entire power supply.

In FIGS. 6 to 8, when the vibration sensor is installed by pressing it against the surface of an object D (not shown) via the mounting flange 21a of the base case 21, the skirt portion 13b of the cover body 13 protruding from the lower surface of the base case 21 While elastically deforming, it retracts into the round hole 21c of the mounting flange 21a, and while compressing the coil spring 24, the cover body 13, the detection member 11, and the casing 14 are pushed upward, and finally, a constant constant based on the coil spring 24. The detection unit 11a of the detection member 11 is pressed against the object D by the pressing force, and the detection unit 11a can be shielded via the skirt portion 13b. On the other hand, the output signal from the microphone 12 can be appropriately analyzed and processed via the circuit boards 31, 41, 41 ..., And then transmitted to the outside as wireless signal data. Since the outer diameter of the skirt portion 13b is gradually reduced downward and the wall thickness is reduced downward, the skirt portion 13b tends to be elastically deformed in the inward contraction direction and smoothly retracts into the round hole 21c of the mounting flange 21a. be able to.

In FIGS. 6 to 8, the circuit boards 31 in the main body case 22 may be provided as needed, and the auxiliary cases 23, 23 ... And the circuit boards 41, 41 ... Are provided with the required number as needed. Just do it. For example, if a lead wire (not shown) of the microphone 12 is directly pulled out through the guide cylinder 14e of the casing 14, the circuit board 31, each auxiliary case 23, and the circuit board 41 can all be omitted. Further, by appropriately changing and allocating the uses of the circuit boards 31, 41, 41 ..., The auxiliary cases 23 for accommodating the circuit boards 41 can be changed to an arbitrary number of 1 or more. Further, the upward connector 44 on the uppermost circuit board 41 may be omitted, or may be used for connecting a charging cable from the outside. Further, the coil spring 24 as the urging member may be a spring material of another type, and may be an elastic member such as an airbag or an air cushion, for example.

The basic case 21 of FIGS. 6 to 8 may be configured separately into a mounting flange 21a and a tubular portion 21b (FIG. 9). A round hole 21f matching the outer diameter of the large diameter portion of the lower half of the tubular portion 21b is formed in the central portion of the mounting flange 21a, and each side of the mounting flange 21a is horizontal toward the center of the round hole 21f. 21 g of screw holes are formed. Therefore, the mounting flange 21a has a fixed height of the tubular portion 21b on an object D (not shown) by inserting a large diameter portion of the tubular portion 21b into the round hole 21f and screwing the set screw 21h into each screw hole 21g. Can be arbitrarily adjusted and installed, and the pressing force of the detection unit 11a by the coil spring 24 can be adjusted and set. The thickness of the mounting flange 21a in FIG. 9 is shown to be larger than the height of the large diameter portion in the lower half of the tubular portion 21b, but the former may be smaller than the latter, or both may be aligned in the same manner. Good.

In the above description, the detection unit 11a of the detection member 11 is not only sharpened diagonally and linearly, but also bulges outward as long as it can form a flat top surface having a small diameter that is pressed against and brought into contact with the object D. , Or it may be sharpened diagonally through a curved surface that invades inward. Further, the detection unit 11a may sharpen the apex angle to either an acute angle or an obtuse angle, and the overall outer shape of the detection member 11 excluding the detection unit 11a may be longer or shorter than the outer diameter. Further, the cross-sectional shape of the detection member 11 is not limited to a circle, and may be, for example, a polygon.

INDUSTRIAL APPLICABILITY The present invention is widely and suitably applicable to applications such as detection of internal abnormalities in mechanical parts such as bearings, detection of flowing water in water pipes, and detection of gas flow in gas pipes.

D ... Object 11 ... Detection member 11a ... Detection unit 12 ... Microphone 13 ... Cover body 14 ... Casing 21 ... Basic case 22 ... Main body case 23 ... Auxiliary case 31, 41 ... Circuit board

Patent applicant Linear Circuit Co., Ltd.

Claims (6)

A detection member having a sharpened tip to form a detection unit, a microphone attached to the base of the detection member, and an elastic cover body for accommodating the detection member together with the microphone are provided, and the detection unit is targeted. A vibration sensor characterized in that when pressed against an object, a part of the cover body hanging around the detection unit elastically deforms to shield the detection unit from external noise. The vibration sensor according to claim 1, further comprising a casing for accommodating the cover body, and projecting the lower end portion of the cover body from the lower end portion of the casing. The vibration sensor according to claim 2, wherein the casing is configured to be fixed to an object. A base case that holds the casing so as to be slidable up and down, a main body case that is connected above the base case, and an urging member that urges the casing downward are added to the cover body. The vibration sensor according to claim 2, wherein the lower end portion protrudes from the lower surface of the foundation case. The vibration sensor according to claim 4, wherein the main body case holds a circuit board. The vibration sensor according to claim 5, wherein one or more auxiliary cases are connected above the main body case, and each of the auxiliary cases holds a circuit board.

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