JPH09196751A - Detector of ultrasonic wave from rotary body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the stabilized detection of ultrasonic waves even in high- speed rotation. SOLUTION: In a receiving plate 18, to which an AE (acoustic emission) sensor 19 is bonded, a through hole 18a, wherein an attaching part 16 of a dressor tool 13 is penetrating, is formed at the approximately central part of the plate 18. The receiving plate 18 is fixed to a front cap body 10 of a dressing device so that the specified gap is formed between the outer surface of the attaching shaft 16 and the inner surface of the through hole 18a. Furthermore, in the inside of the receiving plate 18, a detecting-liquid injecting path 20, whose one end is opened at the inner surface of the through hole 18a, is provided. Then, the detecting liquid is injected from the outside through the detecting-liquid injecting path 20 when the dressor tool 13 is rotated, and the liquid film is formed at the gap between the outer surface of the attaching part 16 and the inner surface of the through hole 18a. The ultrasonic waves generated in the dressor tool 12 is transferred to the receiving part 18 through the liquid film, and the detection of the ultrasonic waves by the AE sensor 19 becomes easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting ultrasonic waves generated from a rotating body, and more particularly, to contact between a dresser tool and a grindstone of a dressing device used for shaping or grinding a grindstone. The present invention relates to a device for improving the detection of ultrasonic waves generated by.

[0002]

2. Description of the Related Art Conventionally, as a device of this type, Japanese Patent Publication 1
As disclosed in Japanese Patent Publication No. 23273, a so-called AE sensor (acoustic emission sensor) arranged in a housing of a dressing device can detect an ultrasonic wave generated at the time of contact between a grindstone and a dresser tool. It is well known and well known by the applicant of the present application that the accuracy of the grinding surface of the grindstone can be improved by observing this ultrasonic signal.

That is, in this publication, a nozzle for sending out detection oil is provided on the wall portion of the housing on the dresser tool side so as to be close to the back surface of the dresser tool, and the AE sensor is provided inside the housing on this wall portion. By being provided so as to be bonded to the AE sensor through the oil film formed between the dresser tool and the nozzle, the nozzle, and the wall portion,
A configuration is disclosed in which ultrasonic waves are transmitted.

[0004]

However, in the above-mentioned conventional apparatus, in order to send the detection oil toward the peripheral portion of the dresser tool, the nozzle is circumferentially spaced from the axis of the dresser shaft. It is configured to be placed. For this reason, as the dresser device becomes a high-speed rotation type, the peripheral speed of the dresser tool increases, and the centrifugal force also increases accordingly, so that an oil film between the dresser tool and the nozzle is less likely to be formed and the smoothness is improved. There is a problem that ultrasonic waves cannot be transmitted.

The present invention has been made in view of the above situation, and even if the dressing device is a high-speed rotating type, it is possible to reliably detect the ultrasonic waves generated when the dresser tool and the grindstone come into contact with each other. A sound wave detecting device is provided. Another object of the present invention is to provide an ultrasonic detecting device capable of forming a stable oil film even in a large dresser device. Another object of the present invention is to provide an ultrasonic detecting device in an existing dressing device in which a receiving plate for AE detection can be easily set.

[0006]

An ultrasonic wave detecting device from a rotating body according to the present invention is an ultrasonic wave detecting device for detecting an ultrasonic wave generated in a rotating body, and is a receiving plate to which an AE sensor is joined or incorporated. The receiving plate is provided with a through hole formed with an inner peripheral surface facing the outer peripheral surface of the rotating shaft of the rotating body with a predetermined gap, and the through hole is formed in the through hole. On the other hand, while providing a detection liquid injection path having an opening end portion on the inner peripheral surface of the receiving plate, when the rotating body is rotated, the detection liquid injection path The detection liquid is supplied to the gap between the outer peripheral surface and the inner peripheral surface of the through hole so that a liquid film is formed in the gap, and ultrasonic waves generated in the rotating body are transmitted through the liquid film to the reception plate. It will be transmitted to.

In such a structure, the AE sensor is attached to the receiving plate, and the receiving plate is formed with a through hole through which the rotating shaft of the rotating body, for example, the rotating shaft of the dresser tool of the dressing device penetrates. The receiving plate is provided so that a predetermined gap is formed between the inner peripheral surface of the through hole and the outer peripheral surface of the rotating shaft of the rotating body. Further, a detection liquid injection path is provided so as to open on the inner peripheral surface of the through hole of the receiving plate, and when the rotation body rotates, the detection liquid is injected through the detection liquid injection path, thereby A liquid film will be formed in the gap between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole of the receiving plate, and when ultrasonic waves are generated in the rotating body, for example,
The ultrasonic waves generated when the dresser tool as the rotating body comes into contact with the grindstone are transmitted to the receiving plate through the liquid film and are easily detected by the AE sensor joined to the receiving plate. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. The members, arrangements, and the like described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.

First, the structure of a dressing apparatus to which the present invention is applied will be described with reference to FIGS. 1 and 2.
The basic structure of this dressing device is the same as that of the existing device except the part to which the present invention is applied. That is, the dressing device shown in FIG. 1 is of a relatively large size and has, for example, a cylindrical housing 1, and two sets of bearings 2a are provided in the housing 1 near both ends thereof. , 2b, 3a, 3b, the dresser shaft 4 is rotatably supported.

Between the bearing 2b and the bearing 3b, an inner sleeve 5 which is externally mounted on the dresser shaft 4 and an outer sleeve 6 which is joined to the inner wall of the housing 1 are respectively interposed. . On the other hand, a through hole through which the dresser shaft 4 penetrates is formed in the center of one opening of the housing 1 where the rear end side of the dresser shaft 4 (the side opposite to the end to which the dresser tool 13 is attached) is located. The rear cover 7 is screwed into the end of the housing 1 to close the opening. The portion of the dresser shaft 4 protruding from the rear lid 7 is connected to a drive device (not shown) so that the rotational force is transmitted. The connection with the drive device is based on a known / known method and is not directly related to the essence of the present invention, and therefore detailed description thereof will be omitted here.

A seal member 8 is provided at a portion adjacent to the through hole facing the inside of the housing 1, and this portion is sealed. Furthermore, the rear lid 7
And the bearing 3a between the dresser shaft 4 and the nut 2
6 is screwed, a spacer 9 is interposed between the bearing 3a and the rear lid 7, and the nut 26 pushes the inner ring side of the bearing 3a and the spacer 9 pushes the outer ring side of the bearing 3a. The bearing 3
The a and 3b are brought into contact with the inner sleeve 5 and the outer sleeve 6 sides.

On the other hand, also in the other opening of the housing 1, the front lid 10 is provided with the housing 1 in the same manner as described above.
The opening is closed by being screwed into. This front lid 1
An annular convex portion 11 having the same outer diameter as the inner diameter of the housing 1 is formed on the surface of the housing 1 on the side of the housing 1.
When the front cover 10 is screwed into the housing 1, the end of the convex portion 11 contacts the bearing 2a, and the bearing 2a contacts the inner sleeve 5 and the outer sleeve 6 side. . Thus, the dresser shaft 4 is held by the housing 1 so as not to move in the axial direction.

Further, the dresser shaft 4 penetrates through the central portion of the front lid 10, and the penetrating portion is sealed by a seal member 12. A dresser tool 13 is attached to a portion of the dresser shaft 4 protruding from the front lid 10. That is, the portion of the dresser shaft 4 that protrudes from the housing 1 is a tapered portion 14 that is tapered so as to have a smaller diameter toward the shaft end, and a screw shaft 15 is projectingly provided on the end surface thereof. There is.

On the other hand, the dresser tool 13 is formed with a shaft hole 13a having the same size and shape as the tapered portion 14 of the dresser shaft 4 in the central portion thereof. ), A mounting portion 16 having a diameter slightly larger than the outer diameter of the dresser shaft 4 is formed to project, and the mounting portion 16 also has the shaft hole 13a. Then, the dresser shaft 4 is inserted into the shaft hole 13a.
The tapered portion 14 of the dresser shaft 13 is fitted into the tapered portion 14 of the dresser shaft 4 by fitting the nut 17 into the screw shaft 15 protruding from the shaft hole 13a in this fitted state. It is fixed to.
In this state, the end surface of the mounting portion 16 has a slight gap in the front lid 10.

On the back side of the dresser tool 13, a predetermined space is formed between the front lid 10 and the portion excluding the mounting portion 16, and this portion has an AE.
A receiving plate 18 for a sensor (acoustic emission sensor) is provided. This receiving plate 18 is A
This is for facilitating the detection of ultrasonic waves by the E sensor 19, and in this example, the entire shape is formed into a substantially rectangular parallelepiped shape. An AE sensor 19 is attached to the outer peripheral surface of the receiving plate 18 by an attaching method described later, so that the AE wave transmitted to the receiving plate 18 can be detected. In addition, A used here
The E sensor 19 itself may be, for example, a known or well-known one such as one using a piezoelectric element, and thus detailed description thereof will be omitted here.

A through hole 18a having an inner diameter slightly larger than the outer diameter of the mounting portion 16 of the dresser tool 13 described above is formed in the central portion of the receiving plate 18, and the mounting portion 16 of the dresser tool 13 is formed. The inner peripheral surface of the through hole 18a and the gap A
The receiving plate 1 so that the receiving plate 1 is located in the through hole 18a.
A part of the back surface side (the surface side facing the front lid body 10) of 8 is joined to the front lid body 10.

On the other hand, between the front side of the receiving plate 18 (the rear side of the dresser tool 13) and the rear side of the dresser tool 13, the receiving plate 18 is joined to the front lid 10 as described above. In the opened state, a gap B is created. Here, although a cylindrical space is formed in the portion of the gap A, an annular cross-sectional area of this cylindrical space in a plane orthogonal to the axial direction of this cylindrical space (the horizontal direction of the paper in FIG. 1) (see FIG. 2). ) Is S1 while the through hole 1 of the receiving plate 18
End face of 8a (face facing the back side of the dresser tool 13)
And the back surface of the dresser tool 13, the area of the portion serving as the discharge passage of the detection liquid formed by the gap B is S
In the case of 2, it is necessary to set the dimensions of each part so that S2 ≦ S1. Since the size of the gap B is very small, it is shown in FIG. 1 that the receiving plate 18 and the dresser tool 13 are almost in contact with each other. ing.

A detection liquid injection passage 20 is provided inside the receiving plate 18. That is, the detection liquid injection path 20 is provided with a connector 21 connected to one end of the detection liquid injection path 20 so as to project to a part of the outer peripheral surface of the receiving plate 18, while the other end is inside the through hole 18 a. It is provided inside the receiving plate 18 so as to open to the peripheral surface.
A connection pipe (not shown) is connected to the connector 21, and a detection liquid for forming a liquid film in the gap A is injected from the outside through the connection pipe and the detection liquid injection passage 20.

When the dresser tool 13 is rotated along with the rotation of the dresser shaft 4 and the detection liquid is injected into the gap A through the detection liquid injection passage 20, the gap A is formed by the detection liquid.
A liquid film is formed on the receiving plate 18 through which the AE wave generated by the contact between the dresser tool 13 and the grindstone is received.
It is transmitted to. The gap B serves as a discharge passage for the detection liquid.

Next, the operation of the present apparatus having the above configuration will be described. The structure for bringing the dresser tool 13 and a grindstone (not shown) into contact with each other in a desired relative positional relationship is based on a known means and is not directly related to the present invention in principle, and therefore will be described here. Will be omitted. First, a drive device (not shown) is started to start rotation of the dresser shaft 4, and the dresser tool 13 is also rotated together with the rotation of the dresser shaft 4.

Then, when the detection liquid is injected from the outside through the detection liquid injection passage 20 at a predetermined flow rate, the detection liquid is opened on the inner peripheral surface of the through hole 18a.
Is discharged from the end portion of the gap A into the gap A, and the detection liquid spreads around the peripheral surface of the mounting portion 16 of the dresser tool 13 located in the gap A as the dresser shaft 4 rotates. Will be done.

When an AE wave is generated in the dresser tool 13 at the moment when the cutting edge (not shown) of the dresser tool 13 comes into contact with the peripheral surface of the grindstone (not shown), the AE wave is generated in the gap A. It is transmitted to the receiving plate 18 through the liquid film formed on the receiving plate 18 and detected by the AE sensor 19 joined to the receiving plate 18. The method of processing the ultrasonic signal detected by the AE sensor 19 may be a known / well-known method and is not directly related to the essence of the present invention, so a detailed description thereof will be omitted.

FIG. 3 is a diagram showing the relationship between the detected flow rate and the S / N ratio. This figure shows the result of testing the change in the S / N ratio with respect to the change in the detected flow rate using the rotation speed as a parameter in the large dresser. Here, S is an AE output during dressing, and N is an AE output during idling of the detection liquid.

In the figure, the characteristic line (dotted line) represented by a triangular plot is the case where the rotation speed is 9000 min ⁻¹ , and the characteristic line (solid line) represented by a square plot is
The case where the number of revolutions is 7,000 min ⁻¹ , and the characteristic line indicated by the chain double-dashed line shows the case where the number of revolutions is 5000 min ⁻¹ . According to this test result, the rotation speed is 9000 min.
^{Even in} the case of ^-1 , it can be said that it is possible to secure an S / N ratio of 30 or more.

Particularly, in order to form a liquid film well in the gap A, the dresser shaft 4 in the cross section taken along the line AA in FIG.
The diameter of the tapered portion 14 is d1, and the inner diameter of the through hole 18a is d.
2. Gap B between the back surface of the dresser tool 13 and the receiving plate 18
When the size of L1 is L1 (see FIGS. 1 and 2), π
It is preferable to set the size of each portion so as to satisfy the relationship of d2 · L1 <(π (d2) ² −π (d1) ² ) / 4. Here, (π (d2) ² −π (d1) ² ) / 4 is the area of the gap A in the plane orthogonal to the axial direction of the dresser shaft 4. That is, it corresponds to the area of the gap A appearing in FIG. Further, π · d2 · L1 is an area when the gap B faces in a direction orthogonal to the dresser axis 4.

Next, a second example of the embodiment of the present invention will be described with reference to FIGS. 4 and 5. This example is one in which the present invention is applied to a small dressing device, and is basically the same as the above-mentioned example, but the point that the receiving plate is configured to also serve as the lid of the housing is described above. This is different from the previous example. That is, the receiving plate 3
In No. 0, an annular protrusion 31 is formed on one surface side thereof, and the outer diameter of the annular protrusion 31 is set to be the same as the inner diameter of the cylindrical housing 32. And
The receiving plate 30 is attached to the housing 32 so that the projection 31 fits into the housing 32, and one opening end side of the housing 32 is closed.

Further, a large diameter portion 33a of the dresser shaft 33 is provided at a portion inside the annular projection 31 of the receiving plate 30.
Is provided with a through hole 30a having an inner diameter slightly larger than the outer diameter. The dresser shaft 33 is configured to be held by the housing 32 using the bearings 34, 35, the inner sleeve 36, and the outer sleeve 37 in the same manner as the example described in FIG. 1, and in this held state. A gap C similar to the gap A shown in FIG. 1 is formed between the outer peripheral surface of the large diameter portion 33a of the dresser shaft 33 and the through hole 30a. The detailed description of the holding portion of the dresser shaft 33 is basically the same as the example of FIG.

Further, a seal member 38 is provided between the large diameter portion 33a of the dresser shaft 33 and the annular projection 31 to seal this portion. A dresser tool 39 is screwed to a portion of the dresser shaft 33 protruding from one side of the housing 32. On the back side of the dresser tool 39 (the side facing the receiving plate 30),
An annular small protrusion 39a is formed. Inside the annular small protrusion 39a, a disc-shaped protrusion 30b protruding from the receiving plate 30 has a minute gap with the dresser tool 39. It is supposed to be located. The small protrusion 3
A substantially same minute gap is formed between 9a and the receiving plate 30.

Further, the receiving plate 30 is provided with a detection liquid injecting passage 40 therein, and the detection liquid injecting passage 40 is provided therein.
Has one end open to the inner peripheral surface of the through hole 30a. The other end side of the detection liquid injection path 40 is branched into two,
The connector 41 is connected to one end thereof, and the other is
It is sealed by a blind plug 43. A connection pipe (not shown) for sending the detection liquid is connected to the connector 41. Then, when the dresser shaft 33 rotates,
When the detection liquid is injected through the detection liquid injection passage 40, a liquid film of the detection liquid is formed in the gap C.

An air injection passage 44 is formed at one corner of the receiving plate 30 (see FIG. 5). One end of the air injection path 44 is opened to the upper surface side of the receiving plate 30 to connect the connector 45, and the other end is opened to the side surface of the receiving plate 30. An air connection pipe (not shown) is connected to the connector 45, and the connector 45
Air can be injected from the outside into the air injection path 44 via the air injection path 44. At the time of this air injection, it is possible to self-diagnose the attachment state of the AE sensor 42 to the reception plate 30 due to the vibration generated in the reception plate 30. Has become.

The AE sensor 42 is joined to the surface of the receiving plate 30 on the housing 32 side, and contacts the dresser tool 39 and the grindstone (not shown) transmitted through the gap C and the receiving plate 30. The AE wave generated by the above can be efficiently detected.

The rear end side of the dresser shaft 33 (the end opposite to the end to which the dresser tool 39 is attached) is connected to a drive source (not shown) by a known means so that the dresser shaft 33 receives a rotational force. However, detailed description of this part will be omitted.

In the embodiment of the invention described above, the case of detecting the AE wave generated when the dresser tool and the grindstone are in contact with each other has been described, but the present invention is limited to such a dresser tool. Needless to say, the present invention can be similarly applied to the case where other rotating bodies generate an AE wave due to some cause during the rotation thereof and the detection of the AE wave is required. Also, the AE sensor 19 (or 42)
Although the above is joined outside the receiving plate 18 (or 30), it may be built inside the receiving plate 18 (or 30).

[0034]

As described above, according to the present invention,
By providing the receiving plate to which the AE sensor is joined so that the liquid film of the detection liquid is formed on the outer peripheral surface of the rotating shaft of the rotating body, unlike the conventional case, the detection liquid is rotated by the rotating body at a high speed. Since it is possible to form a stable liquid film without scattering, it is possible to detect ultrasonic waves stably and reliably even at high speed rotation. Also,
The rotating shaft passes through the through hole provided in the receiving plate,
This is a relatively simple structure in which a liquid film is formed in this gap by forming a gap between the inner peripheral surface of the through hole and the outer peripheral surface of the rotating shaft, and is relatively simple for existing dressing devices and the like. Since it can be applied easily, a dressing device using an inexpensive AE sensor can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a configuration example of an ultrasonic detection device according to a first example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

[FIG. 3] Detecting liquid flow rate and A in a large dressing device
It is a characteristic diagram which shows the relationship with the S / N ratio of an E sensor.

FIG. 4 is a vertical cross-sectional view showing a configuration example of an ultrasonic detection device according to a second example of the embodiment of the present invention.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing 4 ... Dresser shaft 13 ... Dresser tool 13a ... Shaft hole 14 ... Tapered part 16 ... Mounting part 18 ... Receiving plate 18a ... Through hole 19 ... AE sensor 20 ... Detecting liquid injection path 30 ... Receiving plate 30a ... Through hole 33 ... Dresser shaft 33a ... Large diameter part 40 ... Detection liquid injection path 42 ... AE sensor

Claims (2)

[Claims] 1. An ultrasonic detector for detecting ultrasonic waves generated in a rotating body, comprising: a receiving plate having an AE sensor joined or built therein, wherein the receiving plate has an outer peripheral surface of a rotating shaft of the rotating body. And a through hole having an inner peripheral surface facing each other with a predetermined gap formed between them so that the shaft of the rotating body penetrates the through hole, while an opening end is formed on the inner peripheral surface of the receiving plate. A detection liquid injection passage having a portion, and when the rotating body rotates, supplies the detection liquid to the gap between the outer peripheral surface of the rotation shaft and the inner peripheral surface of the through hole via the detection liquid injection passage. Then, a liquid film is formed in the gap, and the ultrasonic wave generated in the rotating body is transmitted to the receiving plate through the liquid film. Sound wave detector. 2. An annular cross-sectional area in a plane orthogonal to the central axis of a cylindrical space formed by the gap between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the through hole of the receiving plate is S1, and the end surface of the receiving plate is When the area of the detection liquid discharge path formed by the gap between the end surface of the rotating body and the end surface of the through hole of the receiving plate is S2, S2≤S1 is satisfied. An ultrasonic detecting device from a rotating body according to claim 1.