JPH10156716A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defectiveness such as damage generated immediately after replacing a grinding wheel so as to shift smoothly to grinding by making the grinding wheel idle for the specified time before starting grinding after replacing the grinding wheel. SOLUTION: A grinding wheel 8 is fitted to a wheel shaft, and a confirmation switch and a wheel rotation start switch are pressed to start rotation of the grinding wheel 8. In this case, grinding work is not started at once, but load to a motor, that is, supply voltage, is monitored, and if the change of load to the motor exceeds the specified value, the generation of abnormality is judged. The rotation of the grinding wheel 8 is therefore stopped forcibly, and a worker is informed of the abnormality. In the case of the change of load to the motor not exceeding the specified value, whether or not the grinding wheel 8 has idled for the specified time, for instance, three minutes, is judged. In the affirmative case, grinding of a workpiece W is started. The damage of the workpiece W caused by the case of the grinding wheel 8 being an off- specification product, insufficient thread fastening, and the like is therefore prevented after replacing the grinding wheel 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding apparatus and, more particularly, to a grinding apparatus capable of accurately preventing a trouble occurring immediately after replacement of a grinding wheel.

[0002]

2. Description of the Related Art When a grinding device is replaced with a grinding wheel in a grinding device, it is assumed that the grinding wheel has a defect such as a crack or forgets to close a bolt. In this case, when the grinding process is started with the grinding wheel, there is a possibility that the work may be damaged due to breakage and scattering or falling off, or the apparatus itself may be damaged.

[0003] Therefore, an object of the present invention is to provide a grinding apparatus capable of preventing troubles such as breakage that occur immediately after replacement of a grinding wheel and smoothly shifting to grinding.

[0004]

According to the present invention, there is provided a grinding apparatus for grinding a workpiece by rotating a grinding wheel, after replacing the grinding wheel and before starting grinding. Further, the grinding wheel is caused to idle for a predetermined time. A protective cover is provided so as to be pivotable between a protection position covering the periphery of the grinding wheel and a retreating position to be separated and retracted, and the protective cover is pivoted to the protection position for a predetermined time for idling the grinding wheel. Is preferred.

When the load on the motor for rotating the grinding wheel changes to a predetermined value or more during idling of the grinding wheel, it is preferable to stop the rotation of the grinding wheel and notify the abnormality.

It is preferable that the door of the apparatus main body is locked for a predetermined time during which the grinding wheel is idled.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partial sectional view of a grinding apparatus according to the present embodiment. This grinding device generally includes a device body 1
, A grinding table 2 and a work holding table (not shown) are provided.

The apparatus main body 1 is provided with a door 3 which can be opened and closed by sliding. In the lower part of the inner surface of this door 3,
A locking piece 4 that is bent downward from the side is attached. The locking piece 4 is provided with a locking hole 4a. On the other hand, an air cylinder 5 is provided inside the apparatus main body 1, and a rod 5 a thereof protrudes and retracts into the locking hole 4 a so that the door 3 can be locked and unlocked.

[0010] As shown in FIG.
Grinding wheel 8 on the tip of the wheel shaft 7
Is bolted. In the present embodiment, the work (not shown) has a cylindrical shape, and its inner peripheral surface is ground by the outer peripheral surface of the grinding wheel 8. Further, the grinding table 2 is provided with a protective cover 10 which is turned by driving the turning cylinder 9 at a protection position around the grinding wheel 8 and a retracted position separated from the protection position.

The drive of the motor 6, the cylinders 5, 9 and the like are controlled by a control device 11 shown in FIG. Control device 11
Has a wheel rotation start switch 12 and a confirmation switch 1
A signal is input from 3 or the like.

Next, the grinding control by the control device 11 will be described with reference to FIG.

That is, when the grinding wheel 8 is mounted on the wheel shaft 7 and the confirmation switch 13 indicating the completion of the work is pressed to provide an input signal (step S1), the wheel diameter is set to the initial value dn (step S1). S2).
If there is an input signal by pressing the wheel rotation start switch 12 (step S3), it is determined whether the door 3 is locked and the protection cover 10 is at the protection position (step S4). , S5), when both conditions are satisfied, the rotation of the grinding wheel 8 is started (step S5).
6).

The grinding operation is not immediately started, and if a change in the load on the motor 6 with respect to the load on the motor 6, ie, the supply voltage, exceeds a predetermined value, an abnormality has occurred, or It is determined that there is a possibility of occurrence (Step S7), the rotation of the grinding wheel 8 is forcibly stopped (Step S8), and the operator is notified of the abnormality (Step S9).
If the load change on the motor 6 does not exceed a predetermined value,
It is determined whether or not the grinding wheel 8 idles for three minutes (step S10). Here, the grinding wheel 8 is caused to idle for 3 minutes when the grinding wheel 8 is defective, for example, when there is an internal crack or the like, when the bolt is forgotten to be stopped, or when the tightening is insufficient. This is because an abnormal situation may occur in which the grinding wheel 8 breaks or falls off after the rotation of the grinding wheel 8 starts. Even if the grinding wheel 8 breaks or falls off,
The abnormality is determined by the change in load as described above,
The rotation of the grinding wheel 8 is stopped. In addition, the fragments of the grinding wheel 8 are prevented from being scattered around by the protective cover 10 and the door 3, which is safe.

If it is determined that the load on the motor 6 does not change and there is no abnormality after three minutes of idling, grinding of the work W is started (step S11). When the grinding of the work W is completed (step S12), the work W
It is determined whether or not the dressing of the grinding wheel 8 is necessary at any time based on the number of times of processing (step S13). If a dress is required, the dressing is performed by sliding a dress whetstone (not shown) against the grinding whetstone 8 (step S14). Then, the current grindstone diameter is calculated from the number of dresses n based on the formula d = dn−n · Δd (step S15). If the grindstone diameter d decreases to the use limit value dmin (step S16),
A whetstone exchange message is issued (step S17).
The same processing is repeated.

[0016]

As is apparent from the above description, according to the grinding apparatus of the present invention, the grinding wheel is allowed to idle for a predetermined time after the replacement and before the start of the grinding process. It is possible to prevent the start of grinding when the product is defective or when screwing is insufficient. Therefore, there is no problem that the work is damaged due to breakage of the grinding wheel or the like.

Further, a protective cover is provided so as to be pivotable around the grinding wheel and at a position separated from the grinding wheel.
For a predetermined time before the start of the grinding process, the protective cover is positioned around the grinding wheel, and the grinding wheel is made to idle, so that even if the grinding wheel scatters, it is guided by the protective cover, and other No damage to parts.

Further, if the load on the motor for rotationally driving the grinding wheel during idling of the grinding wheel changes to a predetermined value or more,
Since the rotation of the grinding wheel is stopped to notify the abnormality, the operator can smoothly shift to the replacement operation of the grinding wheel.

Furthermore, since the door of the apparatus main body accommodating the grinding wheel is locked for a predetermined time before the start of the grinding process after the replacement of the grinding wheel, even if the grinding wheel is broken and scattered, It is possible to reliably prevent the worker from being injured.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a grinding device according to the present embodiment.

FIG. 2 is a partial perspective view of FIG.

FIG. 3 is a block diagram of a grinding device according to the present embodiment.

FIG. 4 is a flowchart showing the grinding control of the grinding device according to the present embodiment.

FIG. 5 is a continuation of the flowchart of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Grinding table 6 Motor 8 Grinding wheel 10 Protective cover 11 Control device

Claims (4)

[Claims] 1. A grinding apparatus for grinding a workpiece by rotating a grinding wheel, wherein the grinding wheel is idled for a predetermined time after replacing the grinding wheel and before starting the grinding process. Grinding equipment. 2. A protective cover which is pivotally disposed between a protection position covering the periphery of the grinding wheel and a retreat position which is separated and retracted, and the protective cover is kept in the protection position for a predetermined time for idling the grinding wheel. A grinding device characterized by turning. 3. The method according to claim 1, wherein, when the load on the motor for rotating the grinding wheel changes to a predetermined value or more when the grinding wheel rotates, the rotation of the grinding wheel is stopped and the abnormality is notified. 3. The grinding device according to 2. 4. The predetermined time for idling the grinding wheel is:
The grinding apparatus according to any one of claims 1 to 3, wherein a door of the apparatus main body is in a locked state.