JPS585147B2 - Grinding wheel truing and dressing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for truing and dressing a grinding wheel using a hard material such as cubic boron nitride as abrasive grains. The rotational direction of the dressing wheel is changed when transitioning from truing to dressing, thereby making it possible to perform truing and dressing effectively and accurately.

That is, in the case of truing a grinding wheel using a truing wheel, the present invention reduces truing resistance by truing the grinding wheel in an up-cut manner,
However, when dressing a grinding wheel using a dressing wheel, dressing the grinding wheel is done by cutting down the grinding wheel to lower the relative circumferential speed of the two and to make it easier for free abrasive grains for dressing to enter between the two. This is a characteristic feature.

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

In FIGS. 1 and 2, reference numeral 10 denotes a grinding wheel rotatably supported on a grinding wheel head in an enclosure. The abrasive grains 12 are fixed with a binder made of resin or metal.

The whetstone head is mounted on the rear part of the bed 13 so as to be movable forward and backward, and the whetstone wheel 10 is rotationally driven in the direction of the arrow by a rotary drive motor in an enclosure installed on the whetstone head.

In addition, a table 14 and a grinding wheel 10 are placed in front of the bed 13.
The table 14 is mounted so as to be movable in a direction parallel to the grinding surface of the table 14, and is moved by a table feed cylinder of a circuit.

Although not shown, the grinding wheel 1 is mounted on the table 14.
A headstock and a tailstock are installed to support the workpiece to be ground at zero.

A guide surface 15 is formed at one end of the table 13,
A base 16 is mounted on the guide surface 15 so as to be slidable in a direction parallel to the direction of movement of the table 14.

A piston rod 18 of a traverse cylinder 17 installed on the table 14 is connected to the base 16, and the base 16 is reciprocated by a constant stroke by the traverse cylinder 17.

A support stand 19 is mounted on the base 16 so as to be slidable in a direction perpendicular to the grinding surface of the grinding wheel 10, and the position of the support stand 19 is adjusted by rotation of the screw shaft 21 by operating the bundle 20. It has become.

A support shaft 22 is rotatably supported on the support stand 19 in parallel with the grinding surface of the grinding wheel 10, and a truing wheel 23 and a truing wheel 23 for truing the grinding wheel 10 are mounted on the support shaft 22.
A dressing wheel 24 for dressing is fixed at a predetermined interval.

The truing wheel 23 has a large number of abrasive grains made of a hard material such as diamond fixed to the outer periphery of a metal base ring by, for example, sintering with a copper alloy, and its width is equal to the width of the grinding wheel 10 in order to reduce truing resistance. It's smaller than that.

The dressing wheel 24 is made of a material having a certain degree of hardness, toughness, and wear resistance, such as tempered steel or hardened steel, and its width is slightly larger than the width of the grinding wheel 10.

The radius of the dressing wheel 24 is the truing wheel 23.
The radius of the grinding wheel 10 and the dressing wheel 24 are made slightly smaller than the outer diameter of free abrasive grains for dressing, which will be described later.
A small gap is formed between the two.

A reversibly rotatable rotary drive motor 25 with a brake is installed on the support base 19 , and the motor 25 is connected to the support shaft 22 via a belt transmission 26 .

As will be clear from the description below, the motor 25 is
During truing, the grinding wheel 10 is driven in the normal direction to truing the grinding wheel 10 in an up-cut manner, and during dressing, it is driven in the reverse direction to dress the grinding wheel 10 in a down-cut manner.

Further, the support base 19 is provided with a dressing liquid supply nozzle 27 corresponding to the dressing wheel 24, and this nozzle 27 is connected via a pump P to a tank 28 for storing the dressing liquid.

The dressing liquid is made by mixing dressing free abrasive grains 29 such as alumina and silicon carbide in the grinding fluid, and a stirring blade 31 is rotated by a motor 30 so that the grinding fluid and the free abrasive grains 29 are not separated. is provided in the tank 28.

In the figure, LSI is a limit switch for confirming the operating end of the table 14, and LS2. LS3 is a limit switch for confirming the original position of the support base 19 and the forward end.

1 Next, the operation of the above-described configuration will be explained based on the control circuit shown in FIG.

When the push button PB for starting truing/dressing is operated in a state where the grinding process by the grinding wheel 10 is completed, the relay CR1 is energized and is self-held by closing the contact cr1.

Based on the excitation of relay CR1, the table feed cylinder of the circuit is operated, and table 14 is moved to the left in FIG.

When the table 14 is moved to a position where the dressing wheel 24 faces the grinding wheel 10 as shown in FIG. 2, the limit switch LSI is activated and the relay CR2 is energized by closing the contact ls1.

This opens the normally closed contact cr2x and relay CR1
is demagnetized and movement of the table 14 is stopped.

By energizing relay CR2, a motor forward rotation command is issued, and motor 25 is started to rotate forward.

At the same time, relay C is closed by closing contact cr2 of relay CR2.
R3 is energized, and based on this, the solenoid 5OL1 is energized and the switching valve 35 is switched.

As a result, pressurized fluid is supplied to the rear chamber of the traverse cylinder 17, and the support base 19 is moved forward along with the piston rod 18 and the base 16, whereby the grinding wheel 10 is trued by the truing wheel 23.

Such truing results in an up-cut as shown in FIG. 3 due to normal rotation of the motor 25. Therefore, the truing resistance can be reduced and run-out of the grinding wheel 10 is not generated, so that the run-out of the grinding wheel 10, which is the purpose of truing, is reduced. You will be able to take it almost completely.

When the grinding wheel 10 is trued in this way, the support base 19 advances to the traverse end, and the forward end confirmation limit switch LS3 is activated, its contact ls3 is closed, relay CR9 is energized, and contact cr9 is activated. Closed.

This energizes relay CR4, and this relay CR4
The relay CR3 is demagnetized by opening of the normally closed contact cr4x.

Based on this demagnetization of relay CR3, the solenoid 5OL1
is demagnetized, the switching valve 35 is returned to its original position, and as a result, pressure fluid is supplied to the front chamber of the traverse cylinder 17, the support stand 19 is traverse-backed, and the grinding wheel 10 removes the uncut portion by the truing wheel 23. Trueed.

Then, the support stand 19 is again attached to the grinding wheel 10 and the dressing wheel 2
4 is returned to the original position facing the limit switch L.
When S2 is actuated, timer TR1 and relay CR5 are energized by the closing of contact cr8 of relay CR8 due to the closing of its contact ls2, which causes its normally closed contact cr
5x is opened, relay CR2 is demagnetized, and motor 25
The power supply to will be cut off.

At the same time, a brake is applied to the motor 25 based on the excitation of the relay CR5, and the inertial rotation of the motor 25 is suddenly stopped.

Then, after a short period of time has elapsed, the timer TR1 times up, its contact tr1 is closed, and the relay CR6 is energized.

By energizing relay CR6, a motor reversal command is issued, and motor 25 is started in reverse for dressing, which will be described below.

At the same time, the pump P is started based on the excitation of the relay CR6, and the dressing liquid is supplied from the nozzle 27 to the gap between the grinding wheel 10 and the dressing wheel 24.

The free abrasive grains 29 in the dressing liquid supplied to the gap between the grinding wheel 10 and the dressing wheel 24 are backed up by the dressing wheel 24 and bite into the binder of the grinding wheel 10 to scrape it off. The grinding wheel 10 is dressed so that the grains protrude from the binder.

Such dressing is carried out by the reverse rotation of the motor 25.
As shown in the figure, it is a down cut, and therefore the relative peripheral speed between the two can be lowered, and the free abrasive grains 29 can easily enter the gap between the two, so that efficient dressing can be performed.

Such dressing continues until the timer TR2, which is excited at the same time as the relay CR6, times up after a set time elapses. When the timer TR2 times up, the contact tr2 is closed, and the relay CR7 is energized. Normally closed contact cr7x is opened and relay CR6 is demagnetized, thereby stopping pump P and motor 25.

Thereafter, the table 14 is moved to the right by the table feed cylinder of the circuit to begin the grinding cycle.

As is clear from the above description, the present invention is applicable to a case where a truing wheel and a dressing wheel are supported side by side on a support shaft rotationally driven by a reversibly rotatable motor, and when a grinding wheel is trued by the truing wheel. In this case, the motor is driven in normal rotation (reverse rotation) to true the grinding wheel in an up-cut, and when dressing the grinding wheel with a dressing wheel, the motor is driven in reverse (normal rotation) in order to dress the grinding wheel in a down-cut. Since the configuration is controlled so that the drive is controlled, the truing resistance can be reduced by up-cutting during truing, and run-out of the grinding wheel can be reliably removed, and during dressing, the down-cutting reduces the truing resistance between the grinding wheel and the dressing wheel. By lowering the relative circumferential speed and making it easier to supply free abrasive grains for dressing between the two, efficient dressing can be performed with less free abrasive grains, and in addition, wear of the dressing wheel can be reduced. This has the effect of reducing the amount of

Note that the present invention is not limited to the configuration described in the embodiments described above. For example, in the embodiments described above, a support base for supporting a truing wheel and a dressing wheel is provided on the table by a traverse cylinder to move the table in the feeding direction. However, this can also be done by moving the table itself, and the forward and reverse rotation of the truing wheel and dressing wheel can be switched between the one-way rotation of the motor and the forward and reverse directions using a clutch, etc. Of course, it is also possible to do so.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a side view of the truing and dressing device, FIG. 2 is a plan view thereof, FIGS. 3 and 4 are explanatory diagrams showing the truing and dressing state, FIG. 5 is a control circuit diagram. 10... Grinding wheel, 14... Table,
16...Base, 17...Traverse cylinder, 19...Support stand, 22...
Support shaft, 23... Truing vehicle, 24...
... Dressing wheel, 25 ... Rotation drive motor, 27 ... Dressing liquid supply nozzle, 28
... Tank, 29 ... Free abrasive grains.

Claims (1)

[Scope of Claims] 1. A grinding wheel whose abrasive grains are made of a hard material such as cubic boron nitride is used for truing and dressing, and a direction toward the axis of the grinding wheel and a direction intersecting with the axis of the grinding wheel are provided. a support stand movable relatively in a direction of a device for supplying free abrasive grains for dressing; a rotary drive device connected to the support shaft for reversibly rotating the truing wheel and the dressing wheel; In the case of dressing the grinding wheel by the dressing wheel during up-cutting and dressing the grinding wheel by the dressing wheel, the grinding wheel device is provided for controlling the direction of rotational drive by the rotational driving device so as to perform truing and dressing of the grinding wheel in down-cutting, respectively. Truing and dressing equipment for grinding wheels. 2. The truing and dressing device for a grinding wheel according to claim 1, wherein the rotational drive device comprises a reversibly rotatable motor with a brake. 3. According to claim 2, the dressing wheel has a slightly smaller diameter than the truing wheel so as to form a small gap between the dressing wheel and the grinding wheel for supplying the free abrasive grains for dressing. Truing and dressing equipment for grinding wheels.