JP4737877B2 - Ultrasonic detector and rotary dresser provided with the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic detection device, and more particularly to an ultrasonic detection device such as a rotary dresser that detects ultrasonic vibration propagating through a rotating shaft that rotates at high speed in a non-contact state.
[0002]
[Prior art]
A rotary dresser is used for shaping the surface of a grindstone for grinding a ball rolling surface or the like of a rolling bearing. Ultrasonic vibration (acoustic emission, generated when the dresser tool comes in contact with the grindstone to improve grinding wheel shaping accuracy, reduce the grinding cost of the grindstone, and further improve the grindstone utilization efficiency to reduce grinding costs. A method for detecting (hereinafter referred to as AE wave) is known.
[0003]
In particular, in recent years, CBN grindstones, diamond grindstones, or new ceramic grindstones that are much harder than ordinary grindstones have been used, and while the wear of the grindstone itself has decreased, the wear of the diamond of the dresser is intense, Changes in the grindstone diameter and sharpness have increased, and it has become impossible to set a large dress cut amount. Moreover, since it is expensive compared with a normal grindstone, the necessity to suppress the removal amount by dressing to the minimum necessary from both sides of productivity and tool cost has arisen. Under these circumstances, when dressing a CBN grindstone, it is necessary to monitor the contact state between the dresser and the grindstone.
[0004]
As shown in FIG. 4, such a rotary dresser has a rotary shaft 32 that is rotatably supported by a housing 30 via a pair of rolling bearings 31, and a dresser tool 33 is attached to one end of the rotary shaft 32, A plurality of diamonds and the like are fixed to the outer periphery of the diamond, and contact with the rotating grinding wheel 34 to shape the surface of the grinding wheel.
[0005]
This rotary dresser is arranged with a gap from the dresser tool 33, and a detection liquid supply unit 35 for supplying a detection liquid toward the center of rotation, and an ultrasonic sensor (hereinafter referred to as AE) provided integrally with the detection liquid supply unit 35. AE waves generated in the dresser tool 33 are detected by the AE sensor 36 through a detection liquid film formed in a gap with the dresser tool 33.
[0006]
Since this rotary dresser supplies the detection liquid from the detection liquid supply unit 35 toward the rotation center of the dresser tool 33, the detection liquid film is hardly applied to the surface of the dresser tool 33 even at high speed rotation. Can be formed. Therefore, there is no scattering of the detection liquid and reduction of the film area, and a good liquid film can be formed. When the dresser tool 33 comes into contact with the grinding wheel 34, an AE wave is generated in the dresser tool 33, and this AE wave is detected by the AE sensor 36 through the liquid film (see JP-A-7-190850).
[0007]
[Problems to be solved by the invention]
Such a conventional method using a detection liquid film requires that the detection liquid supply unit 35 be separately attached to the front surface of the dresser tool 33, and greatly restricts the shape of the dresser tool 33 and the work space of the dresser tool 33. For example, as shown in FIG. 5, in the case of a grindstone for grinding a rolling surface of a rolling bearing, a spiral groove of a ball screw, etc., the grindstone 34 is shaped into an arc shape, but the detection liquid supply unit 35 interferes with the quill 37. However, the turning angle of the dresser tool 33 cannot be set large. Further, since it is necessary to supply grinding coolant from the outside, not only the structure of the dresser itself becomes complicated, but also it cannot be used in dry dressing or dry grinding without using coolant.
[0008]
The present invention has been made in view of such circumstances, and is a small-sized ultrasonic wave that is not subjected to restrictions on the work space by a rotary dresser during dressing and does not require a detection liquid supply unit that supplies a detection liquid from the outside. The object is to provide a detection device.
[0009]
[Means for Solving the Problems]
In order to achieve such an object, the invention according to claim 1 of the present invention is an ultrasonic detector for detecting ultrasonic vibration propagating through a rotary shaft, and a rotary shaft having a tool attached to one end thereof, and the rotary shaft And an ultrasonic vibration detector mounted on the housing, and an annular space having a predetermined gap is formed between the other end of the rotating shaft and the housing. In addition, since the detection unit is disposed opposite to the annular space to form a sealed state, the annular space is filled with a viscous fluid, and ultrasonic vibration propagating through the rotating shaft through the viscous fluid is detected. There is no need to provide a special detection liquid supply unit, and it is possible to form a good liquid film without scattering of the detection liquid and reduction of the film area, and to provide an ultrasonic detection apparatus having a small and simple structure. it can.
[0010]
According to a second aspect of the present invention, in the ultrasonic detection device for detecting ultrasonic vibration propagating through the rotary shaft, the rotary shaft having a tool attached to one end thereof, and the rotary shaft rotated with respect to the housing A bearing that is freely supported, and an ultrasonic vibration detector that is mounted on the housing, the ultrasonic vibration detector being disposed between a pair of rolling bearings that support the rotary shaft, and the detector and the rotary shaft An annular space is formed between the two, and a viscous fluid is filled in the annular space, and the ultrasonic vibration propagating through the rotating shaft through this viscous fluid is detected. There is no need to provide a part, the internal space can be used effectively, and the apparatus can be miniaturized with a simple structure .
[0014]
Furthermore, as in the invention of claim 3, the dresser for shaping the grinding wheel at one end of the rotary shaft is mounted, comprising an ultrasonic vibration detecting apparatus according to claim 1 or 2, the rotary shaft Since the ultrasonic vibration that propagates is detected to detect that the dresser has come into contact with the grinding wheel, the rotary dresser can be miniaturized, and the grinding wheel is shaped like an arc without being restricted by the work space during dressing. Even in the case of shaping, the turning angle can be increased.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment of an ultrasonic detection apparatus according to the present invention.
[0016]
The rotary dresser 1 includes a housing 2, a rotating shaft 5 that is rotatably supported by the housing 2 via a pair of rolling bearings 3 and 4, and a dresser 6 that is detachably attached to one end of the rotating shaft 5. And. A small-diameter step portion 5a is formed at the other end portion of the rotating shaft 5, and a stepped recess 7a formed at the center portion of the detection plate 7 that also serves as a lid member of the housing 2 is interposed via a predetermined radial gap. An annular space is formed.
[0017]
The annular space is filled with grease 8, and a sealed state is maintained between the stepped recess 7a and the small-diameter step portion 5a, and the outflow of the grease 8 is suppressed. An AE sensor 9 is externally attached to the detection plate 7. The AE sensor 9 may be accommodated inside the housing 2 as long as the detection surface is in contact with the detection plate 7. Further, the rotational drive may be performed directly by a DC servo motor (not shown) built in the housing 2 or via a pulley or a belt (not shown).
[0018]
When the grinding surface of the grindstone 10 is worn or the need for shaping occurs, the dresser 6 is rotated while the grindstone 10 is rotated, and the grindstone 10 is dressed. Since the dressing of the grindstone 10 is started when the rotating dresser 6 contacts the peripheral surface of the grindstone 10, the cutting amount is managed from this point. As described above, it is necessary to accurately detect when the dresser 6 contacts the grindstone 10.
[0019]
In this embodiment, the grease 8 filled in the annular space between the small-diameter step portion 5a formed at the other end of the rotating shaft 5 and the stepped recess 7a of the detection plate 7 serves as the detection liquid film, and the dresser 6 serves as the grindstone 10 The AE wave propagated through the detection liquid film of the rotating shaft 5 and the grease 8 is detected by the AE sensor 9 in contact with the detection plate 7. In this embodiment, the detection liquid is grease. However, the present invention is not limited to this, and semi-solid or highly viscous oil may be used.
[0020]
Thereby, there is no need to separately provide a detection liquid supply unit on the front surface of the dresser tool as in the past, and there is no scattering of the detection liquid and reduction of the film area even at high speed rotation, and a good liquid film can be formed. The device is small and simple. Therefore, it is possible to take a large turning angle without being restricted by the work space during dressing. Further, it can be introduced as it is into a conventionally used dresser fixed grinder.
[0021]
In addition, since it is not necessary to supply the detection liquid from the outside, the simplification and handling of the device itself becomes much simpler. Furthermore, the contact between the dresser and the grindstone can be detected by the AE sensor even in dry dressing or dry grinding that does not use the coolant as the detection liquid.
[0022]
FIG. 2 is an enlarged cross-sectional view showing a main part of a second embodiment of the present invention. The same parts and the same parts are denoted by the same reference numerals, and detailed description thereof is omitted.
[0023]
A lid member 12 is attached to the housing 11, and an AE sensor 13 is directly attached to the lid member 12. A stepped hole 14 is formed at the center of the lid member 12, while a small diameter step 5 a is formed at the end of the rotating shaft 5. An annular space having a predetermined radial gap is formed between the small diameter step portion 5a and the stepped hole 14. Grease 8 is filled in the annular space, and the detection surface of AE sensor 13 is opposed. Since a minute radial gap is formed between the inner diameter of the stepped hole 14 and the outer diameter of the rotating shaft 5, the outflow of the grease 8 filled in the annular space can be suppressed.
[0024]
FIG. 3 is a longitudinal sectional view showing a third embodiment of the present invention. The same parts and the same parts are denoted by the same reference numerals, and detailed description thereof is omitted.
The rotary dresser 15 includes a housing 16, a rotary shaft 5 that is rotatably supported on the housing 16 via a pair of rolling bearings 3 and 4, and a dresser 6 that is detachably attached to one end of the rotary shaft 5. And. An annular detection plate 17 is fixed to the central portion of the housing 16 positioned between the pair of rolling bearings 3 and 4, and is opposed to the rotating shaft 5 with a predetermined radial gap. An annular space formed by the detection plate 17 and the rotating shaft 5 is filled with grease 8, and an AE sensor (not shown) in which an AE wave propagating through the rotating shaft 5 is built in the housing 16 through the grease 8. )).
[0025]
In order to suppress the outflow of the grease 8 filled in the annular space, an annular grease holding portion may be provided at the center portion of the detection plate 17 and both ends may be formed smaller in diameter than the holding portion diameter to form a labyrinth. In this way, the detection unit may be arranged anywhere on the rotating shaft 5 in the housing 16 instead of the periphery of the dresser 6, and a small and simple design is possible, and the degree of design freedom is greatly expanded.
[0026]
The AE wave detected by the AE sensor in this way is amplified by the preamplifier, signal-processed by the detection circuit, and taken into the recorder. Although the AE wave output simultaneously with the contact with the grindstone is detected, it has been confirmed that the detection power is very high even with a 0.5 μm cut.
[0027]
The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.
[0028]
【The invention's effect】
As described above in detail, the rotary dresser according to the present invention has the following special effects.
{Circle around (1)} It is not necessary to provide a detection liquid supply unit on the front surface of the dresser tool as in the prior art, and a good liquid film can be formed without scattering of the detection liquid and reduction of the film area even at high speed rotation.
{Circle around (2)} Further, it becomes a small and simple configuration, and it is possible to take a large turning angle without being restricted by a work space at the time of dressing. Therefore, it can be introduced as it is into a conventionally used dresser-fixed grinding machine, and the cost of capital investment can be suppressed.
{Circle around (3)} Since it is not necessary to supply the detection liquid from the outside, the simplification and handling of the apparatus itself becomes much simpler.
(4) Furthermore, contact between the dresser and the grindstone can be detected with high sensitivity by the AE sensor even in dry dressing or dry grinding that does not use the coolant as the detection liquid.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a rotary dresser according to the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part showing a second embodiment of a rotary dresser according to the present invention.
FIG. 3 is a longitudinal sectional view showing a third embodiment of a rotary dresser according to the present invention.
FIG. 4 is a longitudinal sectional view showing a conventional rotary dresser.
FIG. 5 is an explanatory view showing a dressing state of a conventional rotary dresser.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotary dresser 2 ... Housing 3 ... Rolling bearing 4 ... Rolling bearing 5 ... Rotating shaft 5a ... Small diameter step part 6 ... ... Dresser 7 ... Detection plate 7a ... Stepped recess 8 ... Grease 9 ... AE sensor 10 ... Grinding wheel 11 ... Housing 12 ... Lid member 13 ... AE sensor 14 ... Stepped hole 15 ... Rotary dresser 16 ... Housing 17 ... Detection plate 30 ... Housing 31 ... · Rolling bearing 32 ··· Rotary shaft 33 · · · Dresser tool 34 · · · Grinding wheel 35 · · · Detection fluid supply unit 36 · · · AE sensor 37 · · · Quill

Claims (3)

In the ultrasonic detection device that detects ultrasonic vibration propagating through the rotation axis,
A rotating shaft having a tool mounted on one end thereof, a bearing which rotatably supports the rotating shaft with respect to the housing, and an ultrasonic vibration detecting unit mounted on the housing, the other end of the rotating shaft and the An annular space having a predetermined gap is formed with the housing, and the detection unit is disposed opposite to the annular space to form a sealed state. The annular space is filled with a viscous fluid, and the annular fluid is interposed therebetween. An ultrasonic detection apparatus characterized by detecting ultrasonic vibration propagating through a rotation axis. In the ultrasonic detection device that detects ultrasonic vibration propagating through the rotation axis,
A pair of rolling elements, each having a rotating shaft having a tool mounted on one end thereof, a bearing that rotatably supports the rotating shaft with respect to the housing, and an ultrasonic vibration detecting unit mounted on the housing. An ultrasonic vibration detection unit is arranged between the bearings, and an annular space is formed between the detection unit and the rotation shaft. The annular space is filled with a viscous fluid and propagates through the rotation shaft through the viscous fluid. An ultrasonic detection apparatus characterized by detecting ultrasonic vibration. A dresser for shaping a grinding wheel is attached to one end of the rotating shaft, and the ultrasonic vibration detecting device according to claim 1 or 2 is provided, and the dresser is ground by detecting ultrasonic vibration propagating through the rotating shaft. A rotary dresser that detects contact with a grindstone.

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