JPH09254030A - Rotary grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make capable grinding work at a proper rotational speed by accurately detecting a rotational speed of a grinding wheel during grinding work. SOLUTION: A rotational speed detection circuit is provided, which detects a rotational speed of a grinding wheel 10 based on an electric signal from a detection coil 12, by mounting a magnet piece 11 in a rotary part of the grinding wheel 10 and setting up she detection coil 12 it the vicinity of a passing point of the magnet piece 11. When the detected rotational speed is deviated from a proper value, an alarm sound is generated by an alarm sound disptcher 17, also alarm lamps 22b to 22f are lighted.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to cutting, grinding or polishing of hard materials such as concrete, stone materials, refractory bricks, tiles, roof tiles, glass, cast iron pipes, asphalt, blocks, slate, mortar and gypsum board while rotating. The present invention relates to various rotary whetstones such as diamond whetstones.

[0002]

2. Description of the Related Art When cutting, grinding, and polishing so-called hard materials such as concrete, stone materials, cast iron pipes, etc., a diamond grindstone has been conventionally used, and the shape, size, and shape suitable for the type of work material and processing conditions, A grain size diamond wheel is selected.

On the other hand, in the processing with a diamond grindstone, there are various factors that largely affect the processing efficiency, the processing accuracy, the life of the grindstone, etc. Among them, the rotational speed of the grindstone is particularly important.

In processing with a diamond grindstone,
There is an appropriate rotation speed that is determined by the type of work material, the output of the machine, the cutting conditions, the processing conditions such as the feed rate, and the grindstone size.

When processed at an appropriate rotation speed, a machined surface having a predetermined surface roughness is obtained, the machining quality is good without chipping, and the life of the grindstone is long, resulting in a reduction in machining cost. However, when machining is performed under conditions that deviate from the proper rotation speed, machining efficiency, machining accuracy, and machining quality deteriorate, and the life of the grindstone shortens, resulting in higher machining cost.

Therefore, if the rotational speed of the grindstone can always be known during machining and the proper rotational speed can be maintained, it will be a great advantage in terms of machining efficiency, machining accuracy and machining quality. Therefore, conventionally, various devices for measuring the rotational speed of the grindstone have been developed.

The conventional grindstone rotation speed measuring apparatus is roughly classified into a non-contact measuring method and a contact measuring method. As a non-contact measurement method, a light reflection type tachometer, a non-contact capacitance type gap detector, a non-contact eddy current type gap detector, etc. are typical, and a contact type tachometer is used as a contact measurement method. There is a method of measuring the rotation speed of the grindstone rotating shaft.

[0008]

As described above, various rotational speed measuring devices have been conventionally developed, but none of them can accurately know the rotational speed of the rotary grindstone.

For example, since the light reflection type tachometer is strongly affected by chips and grinding fluid, it is impossible to measure the rotational speed of a grindstone during processing. Also, in the case of non-contact capacitance type gap detectors and non-contact eddy current type gap detectors, it is not possible to measure the wheel rotation speed during machining because it is affected by chips and grinding fluid. Because it senses the irregular vibration of, it cannot measure the accurate rotation speed.

That is, these rotational speed measuring devices are
Since a weak signal such as a change in light, electrostatic capacitance, eddy current, etc. is sensed and measured, the presence of chips, grinding fluid, vibration, etc., makes it impossible to immediately measure. Further, in the case of the non-contact capacitance type gap detector and the non-contact eddy current type gap detector, an expensive frequency analysis device is required in actual use.

Further, since the contact type tachometer is not designed to be continuously used, there is a great possibility that the tachometer will be damaged if the tachometer is continuously brought into contact with the grindstone rotating shaft during the working work. Is.

On the other hand, when measuring the rotation axis of the grindstone with the contact type tachometer, there is the above-mentioned problem, and therefore, when the rotation of the pulley directly connected to the rotation axis of the grindstone or the rotation of other parts is measured, the belt slips or the like. Therefore, the rotation speed of the grindstone itself cannot be accurately measured.

As described above, since the conventional grindstone rotation speed measuring device has various problems that cannot be easily overcome, it is possible to directly and accurately measure the rotation speed of the grindstone during the actual working operation. Can not.

Therefore, the problem to be solved by the present invention is to provide a rotating grindstone capable of accurately detecting the rotating speed of the grindstone during the working operation and enabling working at an appropriate rotating speed.

[0015]

In order to solve the above-mentioned problems, a rotary grindstone of the present invention has a magnet piece attached to a rotating portion of the grindstone, and a detection coil or a detection element is installed in the vicinity of a passage point of the magnet piece for detection. A rotation speed detection circuit for detecting the rotation speed of the grindstone based on an induced current generated in a coil or a detection element is provided.

In the rotary grindstone of the present invention, the magnet piece attached to the grindstone passes through a vicinity of a detection coil or a detection element installed in the vicinity of the passing point of the magnet piece as the grindstone rotates during the working operation to detect the magnet piece. A periodic induction current is generated in the coil or the sensing element. Therefore, the rotation speed detection circuit detects the rotation speed of the grindstone based on the periodicity of the induced current.

Further, the present invention is characterized in that a rotation speed display means for detecting the rotation speed detected by the rotation speed detection circuit by at least one of visual sense and auditory sense is provided. By providing such a rotation speed display means, the operator can confirm the rotation speed of the grindstone being processed detected by the rotation speed detection circuit by at least one of visual and auditory senses.

Further, the present invention is characterized by further comprising an alarm generating means for emitting at least one of an alarm sound and an alarm light when the rotation speed detected by the rotation speed detection circuit deviates from an appropriate value.
By providing the alarm generation means, when the rotational speed of the grindstone during processing deviates from an appropriate value, an alarm sound, an alarm light, etc. are emitted to notify the abnormality occurrence, so that the operator can take immediate action. For this reason, the work is continued without noticing that it is out of the proper rotation speed during the work, and the work efficiency, the work accuracy, and the work quality are not adversely affected.

In the rotary grindstone of the present invention, the magnetic force generated from the magnet piece attached to the grindstone is a stronger signal than the signals such as light, electrostatic capacity, eddy current, etc. which the conventional rotation speed measuring device used as the detecting means. Therefore, it is not affected by noises such as chips, grinding fluid and vibration during machining. For this reason,
The rotation speed of the grindstone can be measured accurately. Further, since the magnet piece and the detection coil are not in contact with each other, irregular vibration of the grindstone is not transmitted and the measurement accuracy is not deteriorated, and the durability in continuous measurement is extremely good.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment,
2 is a front view of the same, FIG. 3 is a block diagram showing a circuit configuration, and FIG. 4 is a block diagram showing a configuration of a rotation speed detection circuit and the like.

1 and 2, 10 is a rotary grindstone, 1
Reference numeral 1 is a magnet piece, 12 is a detection coil installed near the passage point of the magnet piece 11, 13 is a main body of a rotation speed detector, and 14 is a work material ground by a grindstone 10. On the front panel of the main body 13 of the rotation speed detector, a main switch 15, a pilot lamp 16, an alarm sound generator 17, an alarm sound stop switch 1
8, a rotation speed setting dial 19, a rotation speed set value display unit 20, a rotation speed display unit 21, a normal lamp 22a, and alarm lamps 22b to 22f are provided.

On the other hand, in the main body 13, as shown in FIG. 3, the grindstone 10 is generated based on the induced current generated in the detection coil 12.
A rotation speed detection circuit 23 that detects the rotation speed of the above, a comparison circuit 24 that compares the detected rotation speed with the rotation speed set value, and the like are built-in.

When performing the grinding process, when the work material 14 is set at a predetermined position and the main switch 15 of the main body 13 is turned on, the pilot lamp 16 is turned on. Turn the dial 19 to set the proper rotation speed value of the grindstone 10, for example, 1200 m.
/ Set minutes etc. Since this set value is always displayed on the rotational speed set value display section 20 during machining, it can be checked at any time.

On the other hand, as shown in FIG. 3, this rotation speed setting value is also input to the comparison circuit 24, and the comparison circuit 24 determines whether or not the speed is appropriate based on this value. This rotation speed set value is set by selecting the most suitable rotation speed value according to the type of the grindstone, the processing conditions, and the like.

Next, the grindstone 10 is rotated to start grinding the work material 14. When the grindstone 10 rotates, the magnet piece 11 also rotates and passes near the detection coil 12, so that a periodic induction current is generated in the detection coil 12, and this current is sent to the rotation speed detection circuit 23 as a signal. The number of times the magnet piece 11 passes near the detection coil 12 is 1 for each rotation.
Since the number of revolutions is measured, the number of revolutions is detected, and the number of revolutions is detected. The number of revolutions is calculated based on this number of revolutions and the circumference of the grindstone 10. To do. The operator can confirm the actual rotation speed of the grindstone 10 being processed at any time by looking at the rotation speed display portion 21.

Here, the rotation speed detecting circuit 23 has a structure as shown in FIG. The periodic induction current generated in the detection coil 12 due to the passage of the magnet piece 11 is sent to the counter 25 and is counted there. However, since the clock 28 sets a certain length of time, the counting within that time is performed. The rotation speed is detected from the number. And the signal is D /
It is sent to the level meter 27 through the A converter 26.

In the comparison circuit 24, the rotation speed detection circuit 23
The actual rotation speed value sent from the device is constantly monitored by comparing it with an appropriate value that has been input in advance, and when they match each other, the normal lamp 22a is turned on. Therefore, the operator can confirm the normal operation by the normal lamp 22a. However, when the rotation speed of the grindstone 10 during the working operation deviates from an appropriate value, the alarm sound generator 17 emits an alarm sound, and the alarm lamps 22b to 22f are turned on to alert the operator. At this time, the greater the degree to which the actual rotation speed deviates from the proper value, the more the number of the alarm lamps 22b to 22f that are turned on sequentially increases.

As described above, when the actual rotation speed value deviates from the proper value, both the alarm sound and the alarm light notify the operator, so that the operator's attention can be surely drawn, and the state where the proper rotation speed deviates is noticed. You will not be able to continue working without it. Here, since the alarm sound emitted from the alarm sound generator 17 needs to reach the operator's ear without being distracted by the noise of the machine or the like, a sound different from the motor sound or the mechanical sound, for example, a bird sound. Sounds and musical sounds are desirable. When it is necessary to immediately stop the alarm sound due to the surrounding conditions, the alarm sound stop switch 18 can be turned off.

On the other hand, as shown in FIG. 1, the actual rotational speed of the grindstone 10 during the working operation, for example, 1150 m / min, is displayed on the rotational speed display portion 21 during the working, so that the operator can By confirming, it is possible to continue the work while maintaining proper work conditions. Therefore,
The processing efficiency, processing accuracy, processing quality, etc. of the work material 14 are comprehensively improved as compared with the conventional one.

In this way, when the rotational speed of the grindstone 10 during processing deviates from an appropriate value, both an alarm sound and an alarm light are emitted to notify the occurrence of an abnormality, so that the operator can take immediate action. For this reason, the work is continued without noticing that it is out of the proper rotation speed during the work, and the working efficiency, the working accuracy, and the working quality are not deteriorated.
In this embodiment, the structure that emits both the alarm sound and the alarm light is adopted, but the structure that emits either one of the alarm sound and the alarm light may be adopted.

Further, the magnetic force generated from the magnet piece 11 attached to the grindstone 10 is a stronger signal than the signals such as light, electrostatic capacity, eddy current, etc. which the conventional rotation speed measuring device used as the detecting means. , Almost unaffected by noise such as chips, grinding fluid and vibration during processing. For this reason,
The rotation speed of the grindstone 10 can be measured extremely accurately regardless of the processing work and the idle rotation.

Further, since the magnet piece 11 and the detection coil 12 are not in contact with each other, the irregular vibration of the grindstone 10 is not transmitted and the measurement accuracy is not deteriorated, and the durability in continuous measurement is extremely good. is there. Since the rotational speed can be measured simply by attaching the magnet piece 11 to the grindstone 10 and installing the detection coil 12 near the passage point,
Not only can it be immediately applied to a conventional rotary grindstone, a grinding machine, etc., but it can also be widely applied to other processing machines and machine tools having a rotating part.

When the magnet piece is attached to the grindstone, the magnet piece is attached to the surface of the grindstone. Alternatively, a recess may be provided on the surface of the grindstone so that the magnet piece is embedded therein. When the magnet pieces are embedded in the recesses, there is an advantage that the magnet pieces do not protrude from the surface of the grindstone and do not hinder the processing work.

[0034]

According to the present invention, the following effects can be obtained.

(1) Attach a magnet piece to the rotating part of the grindstone,
A detection coil or a detection element is installed near the passage point of the magnet piece, and a rotation speed detection circuit that detects the rotation speed of the grinding wheel based on the induced current generated in the detection coil or the detection element is provided. The rotation speed can be accurately detected.

(2) By providing the rotation speed display means capable of detecting the rotation speed detected by the rotation speed detection circuit with at least one of visual and auditory senses, the operator can constantly check the rotation speed of the grindstone during processing. Processing work can be performed.

(3) If the rotation speed detected by the rotation speed detection circuit deviates from the proper value, at least one of the alarm sound and the alarm light is emitted.
By providing the alarm generating means for emitting the alarm, the worker can immediately take action when the rotation speed is abnormal.

(4) Therefore, the work is continued without being aware that the worker deviates from the proper rotation speed during the work, and the work efficiency, the work accuracy, and the work quality are not deteriorated.

(5) Since the magnetic force generated from the magnet pieces attached to the grindstone is strong and is not affected by noise such as chips, grinding fluid and vibration during processing, the rotational speed of the grindstone should be accurately measured. You can Further, since the magnet piece and the detection coil are not in contact with each other, irregular vibration of the grindstone is not transmitted and the measurement accuracy is not deteriorated, and the durability in continuous measurement is extremely good.

(6) Since it is possible to carry out the working operation while always maintaining the grindstone at an appropriate rotation speed, the working efficiency, working accuracy, working quality and the like are greatly improved as compared with the prior art.

(7) Since it has a simple structure, it is low in cost and easy to use.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment.

FIG. 2 is a front view showing the embodiment.

FIG. 3 is a block diagram showing a circuit configuration.

FIG. 4 is a block diagram showing a configuration of a rotation speed detection circuit.

[Explanation of symbols]

 10 Grindstone 11 Magnet Piece 12 Detection Coil 13 Main Body of Rotation Speed Detector 14 Work Material 15 Main Switch 16 Pilot Lamp 17 Alarm Sound Generator 18 Alarm Sound Stop Switch 19 Rotation Speed Setting Dial 20 Rotation Speed Setting Value Display 21 Rotation Speed Display unit 22a Normal lamp 22b to 22f Warning lamp 23 Rotation speed detection circuit 24 Comparison circuit 25 Counter 26 D / A converter 27 Level meter 28 Clock

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiya Ogata 210 Takeno, Ota, Marumachi, Ukiha-gun, Fukuoka Noritake Diamond Co., Ltd. Within

Claims (3)

[Claims] 1. A magnet piece is attached to a rotating portion of a grindstone, a detection coil or a detection element is installed near a passage point of the magnet piece, and a rotational speed of the grindstone is based on an induced current generated in the detection coil or the detection element. A rotary whetstone equipped with a rotation speed detection circuit that detects 2. A rotary grindstone equipped with a rotation speed display means capable of visually or audibly detecting the rotation speed detected by the rotation speed detection circuit. 3. At least one of an alarm sound and an alarm light when the rotation speed detected by the rotation speed detection circuit deviates from an appropriate value.
A rotary whetstone equipped with an alarm generating means that emits one.