JPS5943271B2 - Grindstone finishing truing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for finish truing a grindstone using a hard material such as cubic boron nitride as abrasive grains. be.

In order to repair a whetstone that uses hard materials such as cubic boron nitride as abrasive grains, the whetstone is trued using a truing wheel with diamond grains fixed to the outer periphery, and then a free dressing for dressing is installed between the dressing wheel and the whetstone. There are tools that dress the grinding wheel by supplying granules, but it has been found that if this dressed grinding wheel is further trued in a very small amount using a truing tool, the life of the grinding wheel, that is, the interval between truing and dressing, can be significantly lengthened. .

However, it is difficult to stably make tiny cuts with a truing tool toward the grindstone, but the present invention overcomes this difficulty by using a truing tool that uses the almost constant repulsive force of an elastic means. The gist of the invention is to apply pressure to the grinding surface of a grindstone to finish and true the grindstone by a very small amount with high precision. Embodiments of the present invention will be described below based on the drawings.

Reference numeral 1 denotes a bed of a grinding machine equipped with a grindstone finishing truing device according to the present invention, and a grindstone head 2 is placed on this bed 1 so as to be movable forward and backward toward a workpiece w.

This grinding wheel 3 has abrasive grains of hard material such as cubic boron nitride adhered to the outer circumferential surface of a metal disk in a layered manner, and is rotatable around an axis perpendicular to the forward and backward direction of the grinding wheel head 2. This grinding wheel 3 is rotatably driven by a motor 4 fixed on the grinding wheel head 2 via a pulley and a belt. Reference numeral 5 denotes a grinding wheel cover fixed to the side surface of the grinding wheel head 2 to cover the grinding wheel 3 and a dressing wheel 20, which will be described later. The structure is such that only the portion facing the workpiece w is exposed.

The grinding wheel 3 uses a hard material such as cubic boron nitride as the abrasive grains, which causes little wear and little change in its outer diameter. Unlike the grinding wheel cover that covers the grinding wheel, a front cover whose position is adjusted as the grinding wheel diameter decreases is not provided. Reference numeral 6 denotes a coolant nozzle attached to the front upper part of the grindstone cover 5, and this coolant nozzle 6 is connected to a coolant liquid supply device (not shown) to supply coolant liquid to the grinding point during the grinding process.

Next, the feed device T that moves the grindstone head 2 forward and backward toward the workpiece w will be explained. A feed screw shaft 8 is rotatably supported on the bed 1, and A nut 9 is screwed together.

Reference numeral 10 denotes a servo motor fixed to the bed 1, and this servo motor 10 rotates the feed screw shaft 8 in forward and reverse directions to move the grindstone head 2 forward and backward toward the workpiece W.

A table 11 is placed on the bed 1 so as to be slidable in a direction perpendicular to the advancing and retreating direction of the grinding wheel head 2, in other words, in a direction parallel to the outer peripheral grinding surface of the grinding wheel 3. connected.

13 is a workpiece support device provided on the table 11;
This workpiece support device 13 is designed to rotate and drive the workpiece w while holding it between both centers.

A base 14 is fixed to the table 11 in line with the workpiece support device 13 in the moving direction of the table 11, and a tool stand 15 is positioned on the base 14 in a direction parallel to the advance/retreat direction of the grindstone head 2. It is placed.

A truing wheel 16 is rotatably supported on the tool stand 15 around an axis parallel to the moving direction of the table 11, and this truing wheel 16 is rotated in the same direction as the grinding wheel 3 by a motor 17 fixed on the tool stand 15. Rotationally driven. The truing wheel 16 is made of a metal disc with diamond particles fixed in a layer on the outer periphery, and its width is made smaller than the width of the grinding wheel 3 in order to reduce truing resistance. A base 18 is fixed on the grinding wheel head 2 on the opposite side of the workpiece w with the grinding wheel 3 in between, and a support stand 19 is mounted on the base 18 so as to be able to move forward and backward toward the outer peripheral grinding surface of the grinding wheel 3. ing. The bearing part 29 of the support stand 19 enters into the grinding wheel cover 5 through a window hole 30 made in the grinding wheel cover 5, and the dressing wheel 20 is rotatably mounted in this bearing part 29 facing the grinding wheel 3. This dressing wheel 20 is supported on the support base 1.
A motor 21 fixed on the grinding wheel 9 rotates the grinding wheel 3 in the opposite direction. The dressing wheel 20 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 approximately the same as the width of the grinding wheel 3. Next, the feed applying device 22 for moving the support stand 19 forward and backward toward the grinding wheel 3 will be explained.
3 is rotatably supported, a feed nut 24 fixed to the support base 19 is screwed to the tip of the screw shaft 23, and ratchet wheels 25, 26 are keyed to the rear end.

Cylinder devices 27, 26 are fixed to the base 18, and piston rods 31, 32 of the cylinder devices 27, 28 are fixed to the base 18.
The claws 33 and 34 pivotally supported at the tips are compressed springs 35,
36 and is engaged with the ratchet wheels 25 and 26 in a detachable manner. The position where the pawls 33 and 34 start to engage with the pawl wheels 25 and 26 is adjusted appropriately by baffle plates 37 and 38, and when the pawl 33 is reciprocated by the operation of the cylinder device 27, the screw shaft 23 is moved between the pawl wheels 25 and 26. The support base 1 is rotated forward through the
9 is advanced by a forward amount F, and when the claw 34 is reciprocated by the operation of the cylinder device 28, the screw shaft 23 is reversed via the ratchet wheel 26, and the support base 19 is moved backward by an amount B smaller than the forward amount F.
However, it is starting to be pushed back. 39 is an upward nozzle fixed to the base 18, and this nozzle 39 is connected to the window hole 3.
0 into the grinding wheel cover 5, and is connected to a tank 40 storing dressing liquid via a pump P in order to supply dressing liquid between the grinding wheel 3 and the dressing wheel 20 from below. .

As an example, the dressing liquid is a grinding liquid 101 mixed with 500 y of free particles 41 for dressing (approximately 100 μm in diameter) such as alumina or silicon carbide. Reference numeral 42 denotes a stirring blade which prevents separation of the grinding fluid and loose particles, and is rotationally driven by a motor 60.

Next, a description will be given of the grindstone finishing truing device 43 according to the present invention, which lightly trues the grinding wheel 3 that has been trued and dressed by the truing wheel 16 and the dressing wheel 20 again by a very small amount. A sliding rod 47 is fixed to a guide stand 45 fixed to the upper surface of the grinding wheel cover 5 via a bracket 44 and rotates in a direction parallel to the axis of rotation of the grinding wheel 3, in other words, the outer peripheral grinding surface of the grinding wheel 3. A piston 48, which is fixed to the rear end of the sliding rod 47, is fitted into a cylinder 49 which is fixed to the guide table 45 so as to be movable back and forth in a direction parallel to the guide table 45. A feed shaft 51 is fitted into a holding member 50 integrally fixed to the tip of the sliding rod 47 so as to be slidable in a direction perpendicular to the rotational axis of the grinding wheel 3. A screw shaft 52 supported by the holding member 50 is screwed into the holding member 50 . 53 is the screw shaft 52
It is a knob fixed to the rear end of the.

A leaf spring 54 as an elastic means is fixed to the tip of the feed shaft 51 and extends in the horizontal direction, and a trueing tool 55 is fixed to the free end of the leaf spring 54 above the rotational axis of the grinding wheel 3. has been done. The lower corners of this truing tool 55 are chamfered 56, 56 so that the truing tool 55 can ride on the outer peripheral grinding surface of the grinding wheel 3. As the truing tool 55, diamond particles sintered with a copper-tin alloy are used. Next, the operation of the above embodiment will be explained. In a normal grinding cycle, the workpiece w is supported by the workpiece support device 13.
When the pushbutton switch PBl is pressed after the servo motor 10 is attached to the grinding wheel 3, the rotation of the servo motor 10 is controlled based on the command from the control device 56, whereby the grinding wheel head 2 is reciprocated by a certain amount, and the workpiece w is moved to the grinding wheel 3. Grinding is done by. When the sharpness of the grinding wheel 3 decreases by repeating such grinding cycles, the grinding wheel 3 is trued and dressed.

For this purpose, when the push button switch PB2 is pressed, the cylinder device 27 is activated and the screw shaft 23 is moved between the pawl 33 and the ratchet wheel 25.
The support base 19 is advanced by an amount F, and the dressing wheel 20 is ground by a correction amount S by the grinding wheel 3 (see FIG. 6). Next, the cylinder device 28 is actuated to reverse the screw shaft 23 via the pawl 34 and ratchet wheel 26, and the support base 19 is retracted by the retraction amount B. Subsequently, the table 11 is moved to the left in FIG. 1 by the cylinder device 12 to the truing position, and the truing wheel 16 is positioned slightly to the left of the grinding wheel 3.

When the table 11 is indexed to the truing position, the servo motor 10 is rotated forward based on a command from the control device 56, the grinding wheel head 2 is advanced by a predetermined amount, and the grinding wheel 3 is moved by a truing amount T relative to the truing wheel 16. cut into. Next, the motor 17 is started and the truing wheel 16 is turned to the grinding wheel 3.
, the coolant liquid is ejected from the coolant nozzle 6, the table 11 is moved to the right by the cylinder device 12, and the outer peripheral grinding surface of the grinding wheel 3 is shaped and removed by the truing amount T by the truing wheel 16. be done. In this case, the table 11 is placed directly on the head 1 and is moved with high rigidity and high precision, so that the outer circumferential grinding surface of the grinding wheel 3 is trued with extremely high precision without deflection. After the above-mentioned truing, the grinding wheel 3
and the dressing wheel 20, the retraction amount B of the support base 19 is
A gap D of about 50μ is formed by adding the amount of truing and the amount of truing T. Subsequently, the motor 21 is started to rotate the dressing wheel 20 in the opposite direction to the grinding wheel 3, and the pump P is driven by the motor M to supply dressing liquid from the nozzle 39 to the gap D from below. The loose grains 41 in the dressing liquid supplied to the gap D are backed up by the dressing wheel 20, bite into the bond holding the abrasive grains of the grinding wheel 3, scrape it off, make the abrasive grains protrude from the bond, and remove the abrasive grains from the bond. Dress car 3. When the timer in the control device 56 times up after the set time has elapsed, the motors 21 and M are stopped and the dressing is completed. When dressing is completed, pressure oil is supplied to and discharged from the cylinder 49, the sliding rod 47 is reciprocated, and the truing tool 55 is elastically pressed against the outer peripheral grinding surface of the grinding wheel 3 by the repulsive force of the leaf spring 54. Then, the outer peripheral grinding surface of the traverse side grinding wheel 3 is finished trued by a very small amount by the truing tool 55.

As a result, the abrasive grains of the grinding wheel 3 that were damaged by the loose grains 41 or lifted from the bond during the previous dressing are corrected and shaped. Truing car 16
The amount of truing T that is shaped and deleted by is at most several 10
μ, the repelling force of the leaf spring 55 that presses the truing tool 55 against the outer grinding surface of the grinding wheel 3 is always kept almost constant, and the staking force δ5 is always stably moved toward the grinding wheel 3 in an extremely small amount. It is cut only. To adjust the depth of cut of the truing tool 55 in this finishing truing, the screw shaft 52 is rotated using the knob 53 to adjust the position of the feed shaft 51, and the truing tool 55 is pressed against the outer peripheral grinding surface of the grinding wheel 3. The repulsive force of the leaf spring 54 is adjusted. In the above embodiment, the truing tool 55 is fixed to the free end of the leaf spring 54, but as shown in FIG. The truing tool 155 may be slidably fitted in a direction perpendicular to the rotation axis of the grinding wheel 3, and the truing tool 155 may be pressed against the outer peripheral grinding surface of the grinding wheel 3 by a compression spring 154 having a relatively long spring constant and a small spring constant. 1
56 is a stop member fixed to the grinding wheel cover 5, and the sliding rod 47 is located at the retreating end to stop the true-ing tool 155.
When the truing tool 155 leaves the outer circumferential grinding surface of the grinding wheel 3, the truing tool 155 rides on the stop member 156 and its forward movement is restricted.

In this case, the truing tool is cubic boron nitride,
It is possible to use a suitably rod-shaped material made of a material with little wear such as ceramic or cemented carbide.
- As detailed above, according to the present invention, a truing tool that is pressed against the grinding surface by the repulsive force of the elastic means is mounted on a holding member that is relatively movable in a direction parallel to the grinding surface of the grindstone. As a result, the grindstone can always be stably finished and trued in extremely small amounts with high precision.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a grinding machine equipped with a grinding wheel truing device according to the present invention, FIGS. 2 and 3 are enlarged partial cross-sectional views of FIG. Fig. 3 is a sectional view, Fig. 5 is an enlarged sectional view of Fig. 2, Fig. 6 is a diagram showing the positional relationship between the dressing wheel and the grinding wheel, and Fig. 7 is another example of the finishing truing device for the grinding wheel. It is a figure showing an example. 3... Grinding wheel, 50... Holding member, 5
4...Plate spring (machine means), 55,155...
...Truing tool, 154...Compression spring.

Claims (1)

[Claims] 1. A device for finish truing a grindstone using a hard material such as cubic boron nitride as abrasive grains, and a holding member movable relative to the grinding surface of the grindstone in a direction parallel to the grinding surface of the grindstone by the repelling force of an elastic means. A grindstone finishing truing device characterized by being equipped with a truing tool that is pressed against the grinding surface of the grindstone.