JP3333957B2 - Whetstone dressing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for dressing a grindstone.

[0002]

2. Description of the Related Art In general, in an NC grinding machine, a grindstone using superabrasive grains such as diamond and CBN suitable for highly efficient grinding of a hard workpiece is widely used. In dressing a superabrasive grindstone, a method of dressing the grindstone with a dresser while applying a coolant to the grindstone is usually employed. In this case, in order to efficiently apply the coolant to the grinding point of the grindstone rotating at a high speed, the tip of the coolant nozzle is disposed near the grindstone with a small gap in the vicinity of the grindstone. In addition, in order to prevent the dresser from cutting too far or miss the dresser, it is necessary to accurately manage the dresser cutting start point. Therefore, conventionally, an AE sensor (vibration sensor) is used to detect the contact between the grindstone and the dresser in a state in which the supply of the coolant is stopped.
The relative position of the grindstone and the dresser is controlled by correcting the difference between the command value and the current value.

[0003]

However, according to the conventional dressing method, even if the supply of the coolant is stopped, it takes a considerable time until the coolant in the coolant nozzle runs out. , And there is a problem that the start of dressing is delayed. In addition, when the dressing is started early, water droplets of the coolant may fall from the nozzle onto the dresser, and the AE sensor may malfunction.

It is an object of the present invention to provide a dressing method and apparatus capable of forcibly discharging the coolant in a coolant nozzle in a short time to start dressing early and to prevent a malfunction of a contact detection sensor. is there.

[0005]

In order to solve the above-mentioned problems, a dressing method according to the present invention comprises disposing a coolant nozzle on a grindstone through a minute gap, and before the dressing,
After the supply of coolant to the coolant nozzle is stopped, air is blown into the coolant nozzle and the coolant in the coolant nozzle is forcibly discharged, and then the contact detection sensor detects the contact between the grinding wheel and the dresser. The dressing is performed by dressing the grindstone with a dresser while applying coolant to the grindstone.

The dressing apparatus of the present invention comprises a dresser for dressing a grindstone, a sensor for detecting contact between the grindstone and the dresser, a coolant nozzle for covering the grindstone near a grinding point via a minute gap, It is composed of a liquid supply mechanism for supplying coolant to the coolant nozzle, and a liquid discharge mechanism for ejecting air into the coolant nozzle before dressing to forcibly discharge the coolant in the nozzle.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a dressing device of an NC grinding machine. The grindstone table 1 of the NC grinder is provided with a grindstone 2 using superabrasive grains and a coolant nozzle 3. The tip of the coolant nozzle 3 is arranged near the grinding point of the grindstone 2 so as to cover the grindstone 2 via a minute gap as shown in FIG. The dresser unit 4 of the NC grinding machine is provided with a rotary dresser 5 for dressing the grindstone 2 and an AE sensor 6 for detecting contact between the grindstone 2 and the rotary dresser 5.

The coolant nozzle 3 is connected to a liquid supply mechanism 8. The liquid supply mechanism 8 supplies the coolant in the tank 9 to the coolant nozzle 3 via a check valve 11 and a pipe 12 by a pump unit 10 during work grinding and dressing. It is configured to supply. The coolant nozzle 3 is connected to a drainage mechanism 13,
Is configured to eject air from the upper end of the coolant nozzle 3 from the air solenoid 14 through the pipe 15 and the ejection port 16 into the interior of the coolant nozzle 3 before dressing, thereby forcibly discharging the coolant in the nozzle 3.

Next, a dressing method using the above apparatus will be described. During work grinding, coolant is supplied to the coolant nozzle 3 by the liquid supply mechanism 8 and discharged from the lower end to the grinding point of the grindstone 2. Prior to dressing the grindstone 2, first, the pump unit 10 of the liquid supply mechanism 8 is stopped, and the supply of the coolant to the coolant nozzle 3 is stopped. Next, the air solenoid 14 of the drainage mechanism 13 is opened, and air is blown into the coolant nozzle 3. Thereby, the residual coolant in the coolant nozzle 3 is discharged in a very short time. Therefore, dressing can be started early after work grinding.

Subsequently, the grindstone 2 is rotated with a rotary dresser 5.
And the AE sensor 6 detects both contacts,
Determine the dress starting point. At this time, since the water droplets of the coolant do not drop onto the rotary dresser 5 from the coolant nozzle 3, the AE sensor 6 can be operated correctly. After that, the grindstone 2 is dressed by the rotary dresser 5 while the coolant supply mechanism 8 is activated and the coolant is applied to the grindstone 2.

In the above embodiment, the rotary dresser 5 is used, but a stick type non-rotary dresser may be used. In addition, as the contact detection sensor, AE
A vibration sensor other than the sensor 6 or a sensor that detects contact based on a change in the current value of the grindstone motor can be used. In addition, the present invention is not limited to the above-described embodiment, and can be embodied by appropriately changing the shape and configuration of each part without departing from the spirit of the present invention.

[0012]

As described above in detail, according to the dressing method and apparatus of the present invention, air is blown into the coolant nozzle before dressing, and the coolant in the coolant nozzle is forcibly discharged in a short time. An excellent effect is obtained that dressing can be started early and malfunction of the contact detection sensor can be prevented.

[Brief description of the drawings]

FIG. 1 is a main part side view of an NC grinding machine showing an embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG. 1 showing an arrangement of a grindstone and a coolant nozzle.

[Explanation of symbols]

1 ・ ・ Whetstone base 、 2 ・ ・ Whetstone 、 3 ・ ・ Coolant nozzle 、
5 ・ ・ Rotary dresser 、 6 ・ AE sensor 、 8
..The liquid supply mechanism, 13 ..the drainage mechanism.

Claims (2)

(57) [Claims] A coolant nozzle is arranged on a grindstone with a minute gap therebetween. Before dressing, the supply of coolant to the coolant nozzle is stopped, and air is blown into the coolant nozzle to remove the coolant in the coolant nozzle. A method for dressing a grindstone, comprising, after forcibly discharging, detecting contact between the grindstone and the dresser by a contact detection sensor and dressing the grindstone with a dresser while applying coolant to the grindstone. 2. A dresser for dressing a grindstone,
A sensor that detects the contact between the grindstone and the dresser, a coolant nozzle that covers the grindstone with a small gap near the grinding point, a liquid supply mechanism that supplies coolant to the coolant nozzle during dressing, and a coolant nozzle that is placed inside the coolant nozzle before dressing A grindstone dressing device consisting of a drainage mechanism that ejects air to forcibly discharge the coolant in the nozzle.