JPS6257465B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for a grinding wheel in which hard abrasive grains made of cubic boron nitride or diamond are fixed in layers to the outer peripheral surface of a metal disk.

The purpose of the present invention is to fill the grinding wheel guard with coolant and recover the coolant by utilizing the twisting phenomenon of the coolant, thereby effectively circulating the coolant and increasing the cooling efficiency of the grinding wheel. The purpose is to suppress the thermal expansion of the grinding wheel and maintain stable grinding accuracy over a long period of time.

Generally, a grinding wheel having a layer of abrasive grains made of cubic boron nitride or diamond fixed to the outer periphery of a metal disk hardly causes wear because the abrasive grains are hard. Therefore, even when such a grinding wheel is used for dead stop grinding, there is no dimensional variation due to grinding wheel wear, and highly accurate grinding is possible.

However, since the grinding wheel uses a metal disk, such as aluminum or cast metal, which has a larger coefficient of thermal expansion than a normal grinding wheel, changes in the ambient air temperature due to grinding heat or grinding sparks flowing into the grinding wheel guard may occur. The metal disc thermally expands due to
This caused a problem in that the dimensional accuracy of the workpiece could not be ensured.

The present invention was made to solve these conventional problems, and by filling the grinding wheel guard with coolant, the grinding wheel is effectively cooled, thereby preventing thermal expansion of the grinding wheel. The present invention relates to a cooling device for a grinding wheel characterized by the following features:

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 10 indicates the bed of the grinding machine. A grindstone head 11 is movably placed on this bed 10, and a whetstone shaft 12, which is connected by a belt to a drive motor (not shown), rotates on this grindstone head 11. Bearing possible. At one end of this grinding wheel shaft 12, hard abrasive grains made of cubic boron nitride are fixed in a layer to the outer peripheral surface of a metal disk 13 made of aluminum or cast metal.
A CBN grinding wheel 14 is attached, and this grinding wheel 14 is adapted to be rotationally driven in the direction of mismarking by the drive motor. A grindstone guard 15 having a circular space slightly larger than the diameter of the grindstone wheel 14 is fixed to the side surface of the grindstone head 11 so as to expose the portion that contacts the workpiece W. This whetstone guard 1
A supply port 16 is formed on the outer periphery of the grinding wheel guard 15, and the coolant pumped up from the tank 18 by the pump 17 is supplied from the supply port 16 into the grinding wheel guard 15, so that the grinding wheel guard 15 is filled with the coolant. It's summery. Furthermore, a recovery port 19 is formed in the outer circumference of the grinding wheel guard 15 in a tangential direction, and the coolant is caused to flow toward the recovery port due to the twisting phenomenon of the coolant accompanying the rotation of the grinding wheel 14. , By this, the grinding wheel guard 1
In addition to increasing the circulation efficiency of the coolant within the tank 18, the coolant is collected into the tank 18 without using a special suction pump. still,
20 is a coolant nozzle that supplies the coolant pumped up by the pump 17 to the grinding point P; 21 and 22 are outflow controls bent toward the outer peripheral surface of the grinding wheel at both ends of the opening that exposes the grinding wheel 14; In this section, the grindstone guard 15 is filled with coolant to prevent the coolant from flowing outward.

In this configuration, the grindstone head 11 is advanced toward the workpiece W in the order of rapid feed and grinding feed by an unillustrated feeding device, and grinding is performed. During this grinding process, the grinding wheel 14 is constantly cooled by the coolant filled in the grinding wheel guard 15, and thermal expansion of the grinding wheel 14 due to grinding heat is prevented. Furthermore, even if the grinding sparks generated during this grinding enter the grinding wheel guard 15, the grinding sparks are cooled by the coolant at the inlet of the grinding wheel guard 15, so the grinding sparks will cause the entire inside of the grinding wheel guard 15 to be There is no rise in ambient temperature.

As described above, the present invention is configured to form outflow regulating portions bent in the direction of the outer peripheral surface of the grinding wheel at both ends of the opening that exposes the grinding wheel to the outside, thereby regulating the outflow of coolant from the circular space to the outside. Therefore, the grinding wheel guard can be filled with coolant, and as a result, the entire surface of the grinding wheel can be efficiently cooled, and thermal expansion of the grinding wheel due to grinding heat can be prevented.
This has the advantage that the dimensional accuracy of the workpiece can be maintained uniformly and with high precision over a long period of time.

Furthermore, since the present invention is configured to recover coolant by utilizing the drag phenomenon with respect to the grinding wheel, the coolant can be effectively circulated and the cooling efficiency of the grinding wheel can be increased. This has the advantage that coolant can be recovered without a pump.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view of a main part of the apparatus of the present invention, and FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1. 11... Grinding wheel head, 14... Grinding wheel, 15... Grinding wheel guard, 16... Supply port, 17... Lifting pump, 19... Recovery port, W... Workpiece.

Claims (1)

[Claims] 1 A grinding wheel with hard abrasive grains made of cubic boron nitride, diamond, etc. fixed in a layer on the outer periphery of a metal disk rotatably supported on a grinding wheel head, and a circular space slightly larger than the diameter of this grinding wheel. A grinding wheel guard having outflow regulating portions formed at both ends of an opening that exposes the grinding wheel outwardly from the circular space and bending toward the outer periphery of the grinding wheel to restrict outflow of fluid from the circular space to the outside. a coolant supply device that replenishes coolant from a supply port to fill the circular space of the grindstone guard with coolant; and a coolant supply device that supplies coolant from a supply port to fill the circular space of the grindstone guard, and the circular space of the grindstone guard is filled from a recovery port that is opened in a tangential direction to the outer circumference of the grindstone guard. A cooling device for a grinding wheel, characterized in that it is provided with a coolant recovery device for recovering coolant.