JPS5852791B2 - Toishi Gourmanotsuru Ing Dressing Souch - 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, and its purpose is to truing and dressing the grinding wheel with high precision. It's about dressing.

Recently, in order to truing and dressing a grinding wheel using cubic boron nitride, rotary tools have been developed in which a truing layer made of diamond abrasive grains bonded with a bond and a dressing layer made of hard metal are laminated in the axial direction. The rotating tool is rotated so as to reduce the peripheral speed relative to the grinding wheel, and the rotating tool is given feed in the axial direction of the grinding wheel to true the grinding wheel. A device has been developed that dresses the grinding wheel by moving the rotary tool backward to form a gap between the two and supplying a dressing liquid containing free abrasive grains to the gap while applying the feed to the rotary tool. According to the report, there was a risk that the loose abrasive grains protruding from the dressing layer could scrape off the bond that binds the diamond abrasive grains in the truing layer, causing the diamond abrasive grains to fall off.

The present invention has been made in order to solve such problems, and the rotary tool for truing and dressing a grinding wheel is made of a truing layer in which diamond abrasive grains are bonded together, an isolation layer made of a soft material or voids, and a hard metal. The gist of the present invention is to have a structure in which the dressing layers are laminated in this order in the axial direction.

Embodiments of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a grinding wheel in which abrasive grains of a hard material such as cubic boron nitride are adhered to the outer peripheral surface of an aluminum disk in a layered manner, and is rotated at high speed clockwise in FIG.

2 is a rotary tool, and this rotary tool 2 is made by sintering a layer of a soft metal such as a copper alloy on the outer peripheral side surface of a disc 40 (Fig. 3) of a metal such as tempered steel or hardened steel. Further, diamond abrasive grains 3 are sintered with a copper alloy on the side surfaces thereof, thereby forming a truing layer 4 in which the diamond abrasive grains are sintered with a copper alloy, an isolation layer 5 made of a soft material, and a dressing layer 6 made of a hard metal. The structure is such that they are laminated in this order in the axial direction.

A tool support 7 rotatably supports the rotary tool 2 facing the grinding wheel 1. The tool support 7 is mounted on a traverse table 8 so as to be movable forward and backward relative to the grinding wheel 1 in a direction perpendicular to its grinding surface. It is mounted.

Reference numeral 9 denotes a motor fixed on the tool support 7, which drives the rotary tool 2.
is rotated counterclockwise by this motor 9 via a pulley and a belt, so that the relative circumferential speed with respect to the grinding wheel 1 is reduced.

A feed screw shaft 10 is screwed into the tool support 7 and rotatably supported on the traverse table 8.

A pinion 11 is freely rotatably supported on the feed screw shaft 10, and a pawl 13 pivotally supported on a rotating plate 12 fixed to the pinion 11 engages and disengages from a water wheel 14 keyed to the feed screw shaft 10. They mesh freely.

Therefore, the rack piston 1 based on the operation of the hydraulic cylinder 30
When the pinion 11 is rotated by the forward and backward movement of 5, the pawl 13
, the feed screw shaft 10 is rotated forward via the water wheel 14, and the tool support 7 is moved forward by a predetermined amount.

The pinion 11, the pawl 13, the water wheel 14, the rack piston 15, and the like constitute a cut making device 16 that gives a cut to the rotary tool 2.

Further, a pinion 17 is freely rotatably supported on the feed screw shaft 10, and a rotating plate 18 is fixed to the pinion 17.
A pawl 19 pivotally supported is removably engaged with a water wheel 20 keyed to the feed screw shaft 10.

Therefore, the rack piston 2 based on the operation of the hydraulic cylinder 31
When the pinion 17 is rotated by the forward and backward movement of 1, the pawl 19
, the feed screw shaft 10 is reversely rotated via the water wheel 20, and the tool support 7 is moved backward by an appropriate amount.

The pinion 17, pawl 19, water wheel 20, rack piston 21, etc. constitute a gap providing device 22 that forms a gap t of an appropriate size between the rotary tool 2 and the grinding wheel 1.

The amount of advance given to the tool support 7 by the notch giving device 16 is greater than the amount of retreat given by the gap giving device 22 by the amount of cut for true-ing the rotary tool 2 onto the grinding wheel 1.

The traverse table 8 is placed on the base 23 so as to be slidable in a direction parallel to the grinding surface of the grinding wheel 1, and is given a feed in the direction parallel to the grinding surface of the grinding wheel by a cylinder device 24 (feed applying device). It looks like this.

25 is a nozzle that supplies dressing liquid only to the portion corresponding to the dressing layer 6 in the gap t, and is
It is fixed on the top facing the dressing layer 6, and is connected via a pump P to a tank 26 in which a dressing liquid is stored.

As an example, the dressing liquid is one in which 500 P of free abrasive grains 27 (about 100 μm in diameter) of alumina, silicon carbide, etc. are mixed in 10 J of the grinding liquid.

A stirring blade 28 is rotated by a motor 29 to prevent separation of the grinding fluid and free abrasive grains.

Next, the operation of the above embodiment will be explained based on the control electric circuit shown in FIG.

When the truing/dressing command is sent, the motor 9 is activated to rotate the rotary tool 2, the contact 32 is closed, the relay CR1 is energized, and the switching valve is switched based on the energization of the relay CRIO. Then, pressure oil is supplied to and discharged from the hydraulic cylinder 30, and the feed screw shaft 10 is rotated in the normal direction via the rack and pinion and ratchet mechanism, and the tool support 7 is rotated in the forward direction.
is moved forward by a predetermined amount, and the rotary tool 2 is given a cut to the grinding wheel 1 for truing.

When the hydraulic cylinder 30 reciprocates and returns to its original position, the contact 33 is closed and the relay CR2 is energized, and its normally closed contact CR2 is opened and the relay CR1 is deenergized.

Based on the energization of the relay CR2, the switching valve is switched, pressure oil is supplied to and discharged from the cylinder device 24, and the traverse table 8 and the rotary tool 2 are reciprocated at an appropriate feed rate in a direction parallel to the grinding surface of the grinding wheel. The grinding wheel 1 is trued by a rotary tool 2.

When the traverse table 8 reciprocates and returns to the original position, the contact 34 is closed and the relay CR3 is energized, and the normally closed contact CR3 is opened and the relay CR2 is deenergized.

Based on the energization of relay CR3, the switching valve is switched to supply and discharge pressure oil to and from the hydraulic cylinder 31, and the feed screw shaft 10 is reversely rotated via the rack and pinion and ratchet mechanism, and the tool support 7 is moved backward. A gap t having an appropriate size smaller than the outer diameter of the free abrasive grains 27 is formed between the rotary tool 2 and the grinding wheel 1.

When the hydraulic cylinder 31 reciprocates and returns to its original position, the contact 35 is closed and the relay CR4 is energized, and its normally closed contact CR4 is opened and the relay CR3 is deenergized.

The pump P is activated based on the energization of the relay CR4, and the dressing liquid is jetted from the nozzle 25 and is supplied to the portion of the gap t corresponding to the dressing layer 6. Furthermore, the switching valve is switched to apply pressure to the cylinder device 24. Oil is supplied and discharged, and the traverse table 8 is reciprocated at an appropriate feed rate in a direction parallel to the grinding surface of the grinding wheel.

During this time, the free abrasive grains 27 supplied to the gap t are backed up by the hard metal dressing layer 6 of the rotary tool 2, and are blown onto the bond (metal or synthetic resin) holding the abrasive grains of the grinding wheel 1 to scrape it off. , dressing the grinding wheel 1 by making the abrasive grains protrude from the bond.

At this time, the free abrasive grains 27 protruding from the dressing layer 6 scrape the soft metal isolation layer 5 and form a gap between the dressing layer 6 and the truing layer 4, whereby the free abrasive grains 27 reach the truing layer 4. Therefore, the copper alloy holding the diamond abrasive grains 3 of the truing layer 4 is scraped off by the free abrasive grains 27, and the diamond abrasive grains 3 are prevented from falling off.

When the traverse table 8 reciprocates and returns to its original position, the contact 36 is closed and the relay CR5 is energized.
The normally closed contact cr 5 is opened, the relay CR4 is deenergized, and the truing and dressing of the grinding wheel 1 is completed.

In the above embodiment, the truing layer is formed by bonding the diamond abrasive grains with a copper alloy bond, but the truing layer may be formed by bonding the diamond abrasive grains with a synthetic resin bond.

Alternatively, the soft metal forming the isolation layer may be cut and removed to form a gap between the truing layer and the dressing layer, and this gap may be used as the isolation layer, or the isolation layer may be formed of synthetic resin instead of the soft metal. You may do so.

Further, in order to perform dressing with free abrasive grains as in the above embodiment, it is necessary to move the rotary tool 2 backward relative to the grinding wheel 1 so that a gap is formed between the rotary tool 2 and the grinding wheel 1. Instead, the relative position of the rotary tool 2 with respect to the grinding wheel 1 may be set so that the retraction amount is zero and the gap is zero.

As detailed above, according to the present invention, the rotary tool that is rotationally driven to reduce the relative circumferential speed with the grinding wheel is moved in a direction parallel to the grinding surface of the grinding wheel to true the grinding wheel, and then the grinding wheel is In a device that dresses the grinding wheel by supplying free abrasive grains between the wheel and the rotary tool, the rotary tool is coated with a truing layer in which diamond abrasive grains are bonded together and an isolation layer made of a soft material or voids. Since the structure is such that at least one set of dressing layers made of metal is laminated in this order in the axial direction, even if loose abrasive grains protrude from the dressing layer, they are prevented from reaching the truing layer by the isolation layer. The free abrasive grains do not scrape off the bond that binds the diamond abrasive grains in the truing layer and cause the diamond abrasive grains to fall off, and the grinding wheel is always trued and dressed with high precision.

[Brief explanation of the drawing]

Fig. 1 is a side view of the truing and dressing device for a grinding wheel according to the present invention, Fig. 2 is a view taken in the U direction of Fig. 1, Fig. 3 is an explanatory diagram showing the dressing state, and Fig. 4 is for control. It is an electrical circuit diagram. 1... Grinding wheel, 2... Rotary tool, 3.
...Diamond abrasive grains, 4°°°...Truing layer, 5...Isolation layer, 6...Dressing layer, 1...Tool support, 8...
Traverse table, 9...motor (rotary drive device), 16...cut imparting device, 22...
...Gap providing device, 24...Cylinder device (
feeding device), 25...nozzle, 27...
. . . Free abrasive grains, P . . . Pump, nozzle 25, and pump P constitute a dressing liquid supply device.

Claims (1)

[Claims] 1 Trueing the grinding wheel by moving a rotary tool that is rotationally driven in a direction parallel to the grinding surface of the grinding wheel to reduce the relative circumferential speed of the grinding wheel whose abrasive grains are made of a hard material such as cubic boron nitride. Next, in a grinding wheel truing/dressing device that supplies free abrasive grains between the grinding wheel and the rotating tool to dress the grinding wheel, the rotating tool is connected to a truing layer in which diamond abrasive grains are bonded together by a bond. A truing and dressing device for a grinding wheel, characterized in that at least one set of an isolation layer made of a soft material or voids and a dressing layer made of a hard metal are laminated in this order in the direction of the axis of rotation.