JP7611078B2 - Grinding Machine - Google Patents

Description

The present invention relates to a grinding machine used, for example, as an NC grinding machine.

For example, as shown in Figures 6 and 7, an NC grinding machine 10 is known that includes a bed 11, a grinding wheel head 12 arranged on the bed 11, a rotatable grinding wheel spindle 14 that is attached to the grinding wheel head 12 and holds a grinding wheel 13 at its tip, a grinding wheel spindle motor 15 (tool spindle motor) that rotates the grinding wheel spindle 14, a table 16 arranged on the bed 11 so as to be movable in the Z-axis direction, a work headstock 17 arranged on the table 16 and holds one end of the workpiece W, a tailstock 18 arranged on the table 16 and holds the other end of the workpiece W, a grinding fluid supplying device 19 that supplies grinding fluid when the workpiece W is machined, and an overall cover 20 that covers the grinding wheel head 12, the grinding wheel spindle 14, the grinding wheel spindle motor 15, the table 16, the work headstock 17, the tailstock 18, and the grinding fluid supplying device 19.

In the above-mentioned NC grinding machine 10, the grinding wheel spindle motor 15 is a motor that rotates the grinding wheel spindle 14 via a pulley 21 attached to one end of the output shaft 151, a pulley 22 attached to the grinding wheel spindle 14, and a belt 23 wound around both pulleys 21, 22, and is generally attached to the back of the grinding wheel spindle 14 via a motor base 24 on the wheel head 12. A motor equipped with a self-ventilating cooling fan 25 that is rotated by the rotation of the output shaft 151 is generally used as the grinding wheel spindle motor 15, but this grinding wheel spindle motor 15 has the following problems.
The heat generated by the grinding wheel spindle motor 15 is released by the motor cooling fan 25, so that the grinding wheel head 12 is heated and thermally expands, causing the grinding wheel spindle 14 to be thermally displaced, which affects the dimensional accuracy of the workpiece W.
b. The motor cooling fan 25 of the grinding wheel spindle motor 15 blows the grinding fluid mist containing grinding chips around the grinding wheel spindle motor 15, which causes the grinding wheel spindle motor 15 and the belt 23 to become dirty, which may cause the grinding wheel spindle motor 15 to break down or the belt 23 to slip.

In particular, NC grinding machines are equipped with an overall cover 20 that covers the entire machine to prevent scattering of the grinding wheel 13 if it breaks, to prevent coolant from scattering, and to prevent being pinched by moving parts. In this case, the overall cover 20 creates an enclosed space, making the effects of a and b above more pronounced.

For example, in a machine tool that supports a spindle head body that moves up and down on the front of a column, has a spindle drive motor fixed to the spindle head body, and has a spindle head cover that covers the spindle drive motor and the spindle head body for the purpose of dust protection, etc., an exhaust duct is attached to the spindle drive motor to prevent thermal displacement of the spindle head when the spindle drive motor is in operation, the inlet of the exhaust duct is connected to an exhaust port formed at the rear end of the spindle drive motor, and the outlet of the exhaust duct is opened to the outside of the spindle head cover (see Patent Document 1).

Japanese Utility Model Application Publication No. 2-35660

However, in the NC grinding machine 10 shown in Figures 6 and 7, even if the grinding wheel spindle motor 15 is covered with a motor cover based on the machine tool described in Patent Document 1, an exhaust duct is attached to the motor cover, the inlet of the exhaust duct is connected to an exhaust port formed in the motor cover of the grinding wheel spindle motor 15, and the outlet of the exhaust duct is opened to the outside of the overall cover 20, the above problem b cannot be solved, and it is not possible to prevent breakdowns of the grinding wheel spindle motor 15, etc., or slippage of the belt caused by dirt on the grinding wheel spindle motor 15, belt, etc.

The object of the present invention is to solve the above problems and provide a grinding machine which can improve the machining accuracy of the workpiece by suppressing the thermal expansion of the grinding wheel head due to heat generated by the grinding wheel motor and preventing thermal displacement of the grinding wheel , and which can prevent failure of the grinding wheel motor, etc. and belt slippage caused by dirt on the grinding wheel spindle motor, belt, etc.

To achieve the above objective, the present invention has the following aspects:

1) A grinding machine comprising: a bed, a table arranged on the bed, a work head arranged on the table and holding one end of a workpiece, a tailstock arranged on the table and holding the other end of the workpiece, a grinding wheel head arranged on the bed, a rotatable grinding wheel spindle mounted on the grinding wheel head and holding a grinding wheel at its tip, a grinding wheel spindle motor for rotating the grinding wheel spindle , a grinding wheel spindle side pulley attached to an end of the grinding wheel spindle opposite to the end where the grinding wheel is held, a motor side pulley attached to one end of a motor output shaft of the grinding wheel spindle motor, a belt hung on the grinding wheel spindle side pulley and the motor side pulley and transmitting rotation of the motor output shaft of the grinding wheel spindle motor to the grinding wheel spindle side pulley, and an overall cover that covers the grinding wheel head, the grinding wheel spindle, the grinding wheel spindle motor, the table, the work head and the tailstock ,
a grinding machine in which the grinding wheel spindle motor is covered by a motor cover, the motor cover is provided with an intake port and an exhaust port that connect the inside and outside of the motor cover, the intake port of the motor cover is connected to the outside of the overall cover by an intake duct, the exhaust port of the motor cover is connected to the outside of the overall cover by an exhaust duct, and the grinding wheel spindle side pulley, the motor side pulley and the belt are arranged within the overall cover outside the intake duct and the exhaust duct .

2) The grinding machine described in 1) above, wherein the grinding wheel spindle motor is a self-cooled motor having a cooling fan provided inside the motor cover and rotated by the rotation of the motor output shaft, and the rotation of the cooling fan causes air outside the overall cover to be sent through the intake duct and the intake port into the motor cover of the grinding wheel spindle motor , and is exhausted to the outside of the overall cover through the exhaust port and the exhaust duct.

3) A grinding machine as described in 2) above, wherein heat dissipation fins are provided around the grinding wheel spindle motor within the motor cover, the cooling fan is covered by a cooling fan cover provided within the motor cover, one end of the cooling fan cover communicates with the intake port and the other end of the cooling fan cover opens toward the grinding wheel spindle motor and the heat dissipation fins, and when the cooling fan rotates, air outside the overall cover passes through the intake duct and the intake port into the cooling fan cover, removes heat from the grinding wheel spindle motor via the heat dissipation fins, and is then exhausted to the outside of the overall cover through the exhaust port and the exhaust duct.

4) The grinding machine according to any one of 1) to 3) above, wherein the wheel spindle motor is fixed to the wheel head via a base, and a cooling fluid passage is formed in the base.

According to the grinding machines 1) to 4) above, the air outside the overall cover can be taken into the motor cover through the intake duct and intake port to cool the grinding wheel spindle motor, and the hot air after cooling the grinding wheel spindle motor can be discharged to the outside of the overall cover through the exhaust port and exhaust duct. Therefore, it is possible to suppress the thermal expansion of the grinding wheel spindle due to heat generation by the grinding wheel spindle motor, and it is possible to prevent thermal displacement of the grinding wheel spindle , thereby improving the machining accuracy of the workpiece.

Furthermore, according to the grinding machines described above in 1) to 4), the air taken into the motor cover does not contain grinding fluid mist, etc., so that it is possible to prevent breakdowns of the grinding wheel spindle motor, belt, etc. and belt slippage caused by dirt on the grinding wheel spindle motor, belt, etc.

According to the grinding machine of 2) above, the rotation of the cooling fan sends the air outside the overall cover through the intake duct and the intake port into the motor cover of the grinding wheel spindle motor, and the air cools the grinding wheel spindle motor, so that the thermal displacement of the grinding wheel spindle caused by the heat generated by the grinding wheel spindle motor can be suppressed. Also, the air that has cooled the grinding wheel spindle motor and has become hot is exhausted to the outside of the overall cover through the exhaust port and the exhaust duct.

According to the grinding machine of 3) above, when the cooling fan rotates, the air outside the overall cover passes through the intake duct and the intake port into the cooling fan cover, and after removing heat from the grinding wheel spindle motor via the heat dissipation fins, the air is discharged to the outside of the overall cover through the exhaust port and the exhaust duct, so that the grinding wheel spindle motor can be cooled efficiently.

According to the grinding machine of 4) above, by flowing a cooling fluid through the cooling fluid passage of the base, the heat generated by the grinding wheel motor during operation is prevented from being transmitted to the grinding wheel head. Therefore, the thermal expansion of the grinding wheel head due to the heat generated by the grinding wheel motor can be suppressed, and the thermal displacement of the grinding wheel can be prevented, thereby improving the machining accuracy of the workpiece.

1 is a schematic plan view showing a first embodiment of a grinding machine according to the present invention; FIG. 2 is a schematic side view showing the grinding machine of FIG. 1 . FIG. 2 is a partially enlarged view of FIG. FIG. 4 is a schematic plan view showing a second embodiment of a grinding machine according to the present invention. FIG. 5 is a schematic side view of the grinding machine of FIG. 4 . FIG. 1 is a schematic plan view showing a conventional grinding machine. FIG. 7 is a schematic side view of the grinding machine of FIG. 6 .

The first embodiment of the invention will now be described with reference to the drawings.

1 and 2 show a schematic overall configuration of a first embodiment of an NC grinding machine to which a grinding machine according to the present invention is applied, and FIG. 3 shows a main portion of FIG.

In the following explanation, the same items and parts as those shown in Figures 6 and 7 are denoted by the same reference numerals and will not be explained further.

The grinding wheel spindle motor 15 of the NC grinding machine 1 shown in Figures 1 and 2 is covered by the motor cover 2 within the overall cover 20. The motor cover 2 is provided with an intake port 3 and an exhaust port 4 that communicate the inside and outside of the motor cover 2, and the intake port 3 of the motor cover 2 and the outside of the overall cover 20 are communicated by an intake duct 5, and the exhaust port 4 of the motor cover 2 and the outside of the overall cover 20 are communicated by an exhaust duct 6. The intake duct 5 and the exhaust duct 6 are adapted to expand and contract when the grinding wheel head 12 moves in the front-rear direction (X-axis direction). The connection between the motor cover 2 and the intake duct 5 and the exhaust duct 6 is airtight, so that air inside the motor cover 2 does not leak.

As shown in Fig. 3, a plurality of heat dissipation fins 7 are provided at intervals in the circumferential direction around the grinding wheel spindle motor 15 inside the motor cover 2. The end face of the grinding wheel spindle motor 15 on the pulley 21 side is in contact with the inner surface of the motor cover 2. The cooling fan 25 is provided on the opposite side of the end face of the grinding wheel spindle motor 15 on the pulley 21 side, and is covered by a cooling fan cover 8 provided on the inner side of the motor cover 2. The left end of the cooling fan cover 8 leads to the air intake 3. The right end of the cooling fan cover 8 opens toward the grinding wheel spindle motor 15 and the heat dissipation fin 7, and the heat dissipation fin 7 is located within the range of the right end opening of the cooling fan 25 when viewed from the right side. The air sent by the cooling fan 25 hits the grinding wheel spindle motor 15 and all the heat dissipation fins 7. As the cooling fan 25 rotates, air outside the overall cover 20 passes through the intake duct 5 and the intake port 3 and enters the cooling fan cover 8, and then removes heat from the grinding wheel spindle motor 15 via the heat dissipation fins 7, before being exhausted to the outside of the overall cover 20 through the exhaust port 4 and the exhaust duct 6.

In addition, a cooling fluid passage 9 is formed in the base 24 that fixes the grinding wheel spindle motor 15 to the grinding wheel head 12. A cooling fluid flows through the cooling fluid passage 9 of the base 24, so that the heat generated by the grinding wheel spindle motor 15 is prevented from being transmitted to the grinding wheel head 12.

In the above-mentioned NC grinding machine 1, when the output shaft 151 of the grinding wheel spindle motor 15 rotates during operation of the NC grinding machine 1, the cooling fan 25 rotates accordingly, and the air outside the overall cover 20 passes through the intake duct 5 and the intake port 3 and enters the cooling fan cover 8, then absorbs heat from the grinding wheel spindle motor 15 via the heat dissipation fins 7, and is then exhausted to the outside of the overall cover 20 through the exhaust port 4 and the exhaust duct 6. Therefore, the thermal expansion of the grinding wheel head 12 due to heat generated by the grinding wheel spindle motor 15 can be suppressed, and the thermal displacement of the grinding wheel spindle 14 can be prevented, improving the machining accuracy of the workpiece W.

In addition, the air sucked in by the cooling fan 25 does not contain grinding fluid mist, etc., so it is possible to prevent malfunctions of the grinding wheel spindle motor 15 and belt slippage caused by dirt on the grinding wheel spindle motor 15 and belt, etc.

4 and 5 show a schematic overall configuration of a second embodiment of an NC grinding machine to which the grinding machine according to the present invention is applied. In the following description, the same components and parts as those shown in Figs. 1 and 2 are designated by the same reference numerals and will not be described.

The difference between the NC grinding machine 30 shown in Figures 4 and 5 and the NC grinding machine 1 shown in Figures 1 and 2 is that instead of the table 16, the saddle 31 on which the grinding wheel head 12 and the grinding wheel shaft motor 15 are placed moves in the Z-axis direction. In this case, the intake duct 5 and the exhaust duct 6 also move in the Z-axis direction, so that the ducts 5 and 6 cannot be fixed to the overall cover 32 as in the NC grinding machine 1 shown in Figures 1 and 2. For this reason, in this second embodiment, the entire back side of the overall cover 32 is opened, and the intake duct 5 is formed to also serve as the grinding wheel head cover 33 that surrounds the entire grinding wheel head 12, and the motor cover 2 and the exhaust duct 6 are arranged inside the grinding wheel head cover 33. And, bellows 34 are provided between the left and right side edges of the rear side opening of the overall cover 32 and the left and right side surfaces of the grinding wheel head cover 33 to prevent the grinding fluid mist and the like from leaking out of the machine.

By configuring in this way, even in an NC grinding machine 30 in which the grinding wheel head 12 moves in the Z-axis direction, it is possible to suppress thermal expansion of the grinding wheel shaft 14 due to heat generated by the grinding wheel shaft motor 15, just like the NC grinding machine 1 of the first embodiment, and it is possible to prevent thermal displacement of the grinding wheel shaft 14 and improve the machining accuracy of the workpiece W. Furthermore, since the air sucked in by the cooling fan 25 does not contain grinding fluid mist, etc., it is possible to prevent breakdowns of the grinding wheel shaft motor 15, etc., and belt slippage caused by dirt on the grinding wheel shaft motor 15, belt, etc.

In the above-mentioned two embodiments, the grinding machine according to the present invention is applied to an NC grinding machine, but the present invention is not limited to this and can also be applied to an ordinary grinding machine .

The grinding machine according to the present invention is suitably used as an NC grinding machine, for example .

1: NC grinding machine, 2: motor cover, 3: intake port, 4: exhaust port, 5: intake duct, 6: exhaust duct, 7: heat dissipation fin, 8: cooling fan cover, 9: cooling fluid passage, 11: bed, 12: grinding wheel head, 13: grinding wheel, 14: grinding wheel spindle, 15: grinding wheel spindle motor, 16: table, 17: work head, 18: tailstock, 20: overall cover, 24: base, 25: cooling fan, 30: NC grinding machine, 31: saddle, 32: overall cover, 33: grinding wheel head cover, 34: bellows

Claims (4)

a grinding machine comprising: a bed; a table disposed on said bed; a work head stock disposed on said table and holding one end of a workpiece; a tail stock disposed on said table and holding the other end of the workpiece; a grinding wheel head disposed on said bed; a rotatable grinding wheel spindle provided on said grinding wheel head and holding a grinding wheel at its tip; a grinding wheel spindle motor for rotating said grinding wheel spindle ; a grinding wheel spindle side pulley attached to an end of said grinding wheel spindle opposite to the end where the grinding wheel is held; a motor side pulley attached to one end of a motor output shaft of said grinding wheel spindle motor; a belt hung on said grinding wheel spindle side pulley and said motor side pulley and transmitting rotation of said motor output shaft of said grinding wheel spindle motor to said grinding wheel spindle side pulley; and an overall cover which covers said grinding wheel head, said grinding wheel spindle, said grinding wheel spindle motor, said table, said work head stock and said tail stock ,
a grinding machine in which the grinding wheel spindle motor is covered by a motor cover, the motor cover is provided with an intake port and an exhaust port that connect the inside and outside of the motor cover, the intake port of the motor cover is connected to the outside of the overall cover by an intake duct, the exhaust port of the motor cover is connected to the outside of the overall cover by an exhaust duct, and the grinding wheel spindle side pulley, the motor side pulley and the belt are arranged within the overall cover outside the intake duct and the exhaust duct . 2. The grinding machine according to claim 1, wherein the grinding wheel spindle motor is a self-cooled motor having a cooling fan provided inside the motor cover and rotated by rotation of the motor output shaft, and the rotation of the cooling fan causes air outside the overall cover to be sent through the intake duct and the intake port into the motor cover of the grinding wheel spindle motor, and is exhausted to the outside of the overall cover through the exhaust port and the exhaust duct. 3. The grinding machine according to claim 2, wherein heat dissipation fins are provided around the grinding wheel spindle motor within the motor cover, the cooling fan is covered by a cooling fan cover provided within the motor cover, one end of the cooling fan cover communicates with the intake port and the other end of the cooling fan cover opens toward the grinding wheel spindle motor and the heat dissipation fins, and when the cooling fan rotates, air outside the overall cover passes through the intake duct and the intake port into the cooling fan cover, removes heat from the grinding wheel spindle motor via the heat dissipation fins, and is then exhausted to the outside of the overall cover through the exhaust port and the exhaust duct. 4. The grinding machine according to claim 1 , wherein the wheel spindle motor is fixed to the wheel head via a base, and a cooling fluid passage is formed in the base .

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