JP2022177587A - Grind stone correction method - Google Patents

Abstract

To provide a technology that removes loose abrasive grains occurring on a surface of a ground surface due to dressing (grind stone correction) in which an outer peripheral surface of a grind stone is ground with a dresser.SOLUTION: A grind stone correction method includes: a dressing step in which a dresser cuts into an outer peripheral surface of a rotating grind stone by a predetermined cut-in amount and is moved in a width direction of the grind stone to grind the outer peripheral surface and thereby form a ground surface on the outer peripheral surface of the grind stone; and a loose abrasive grain removal step in which the dresser is retreated relative to the grind stone in a range smaller than the cut-in amount after the dressing step and then the dresser is moved in the width direction to remove loose abrasive grains on the outer peripheral surface which occur in the dressing step.SELECTED DRAWING: Figure 4

Description

FIELD OF THE DISCLOSURE The present disclosure relates to a grinding wheel correction method.

Conventionally, there is known a technique of dressing a grindstone (grindstone correction) by bringing a dresser into contact with the outer peripheral surface of the grindstone and relatively moving the grindstone and the dresser in the grindstone width direction (Patent Document 1). .

JP 2020-179431 A

In the whetstone correction, since the grinding surface is formed by grinding the outer peripheral surface of the whetstone with a dresser, loose abrasive grains as the whetstone are generated on the surface of the grinding surface. If the object to be ground is ground without removing the loose abrasive grains, scratches may occur on the surface of the object to be ground. Therefore, a technique for removing loose abrasive grains generated during grinding wheel repair is desired.

The present disclosure can be implemented as the following forms.

(1) According to one aspect of the present disclosure, there is provided a grindstone repair method. This grindstone repairing method is a grindstone repairing method in which a dresser cuts into the outer peripheral surface of a rotating grindstone by a predetermined depth of cut, and the dresser is moved in the width direction of the grindstone to shave the outer peripheral surface. a dressing step of forming a grinding surface on the outer peripheral surface of the grindstone; after the dressing step, the dresser is relatively retreated with respect to the grindstone within a range of less than the depth of cut; and a free abrasive grain removing step of removing free abrasive grains on the grinding surface generated in the dressing step by moving in a direction. According to this aspect, after the dressing step, the dresser is moved back in the width direction with respect to the rotating grindstone after the dresser is retracted relative to the grindstone in a range less than the depth of cut. Abrasive grains can be removed.
(2) In the above mode, in the free abrasive grain removal step, the dresser movement distance, which is the distance that the dresser moves in the width direction while the grindstone rotates once, is the distance that the grindstone moves by 1 in the dressing step. It may be the same as the distance the dresser moves in the width direction while rotating. According to this aspect, it is possible to improve the probability of contact between the dresser and the free abrasive grains in the free abrasive grain removing step. That is, free abrasive grains adhering to the grinding surface of the rotating grindstone can be more reliably removed by the dresser.
(3) In the above mode, in the step of removing free abrasive grains, the distance by which the dresser is relatively retreated may be 0.5 times or more and 0.6 times or less of the depth of cut. According to this aspect, it is possible to further improve the probability of contact between the dresser and the free abrasive grains in the free abrasive grain removing step. That is, free abrasive grains adhering to the grinding surface of the grindstone can be more reliably removed by the dresser.
(4) In the above mode, the dresser may be a single stone dresser. According to this form, a single stone dresser can be used as a dresser.
(5) In the above mode, the dresser is an implied dresser having a length X times (where X is a number greater than 1) that of the single stone dresser in the width direction on a tip end side facing the outer peripheral surface, When the dressing step and the loose abrasive grain removing step are performed using the single-stone dresser and the dresser moving distance is Y, the dressing step and the loose abrasive grain removing step are performed using the implime dresser. may be X times the Y.
The present disclosure can be implemented in various forms other than the above grindstone repair method. For example, a method for manufacturing a grinding wheel repairing device, a method for controlling a grinding wheel repairing device, a method for manufacturing a grinder equipped with a grinding wheel repairing device (hereinafter referred to as a grinding wheel repairing system), a control device for a grinding wheel repairing system, a control method for a grinding wheel repairing system, and the like It can be realized in the form of a computer program for realizing the control method, a non-temporary recording medium recorded in the computer program, or the like.

The top view which shows the whole structure of a grinder. A flow chart which shows a flow of a whetstone correction method. 4 is a flow chart showing the flow of the loose abrasive grain removing process. The figure for demonstrating the whetstone correction method in 1st Embodiment. 5 is an enlarged view of the area of FIG. 4; FIG. The figure for demonstrating the whetstone correction method in 2nd Embodiment.

A. First embodiment:
FIG. 1 is a plan view showing the overall configuration of the grinding machine 1. FIG. FIG. 1 schematically shows a state in which the grinder 1 is placed on a horizontal installation surface such as a floor and viewed from above. The grinder 1 is a machine tool that grinds the surface of the workpiece W by bringing the grindstone 11 into contact with the workpiece W as an object to be ground and moving the workpiece W and the grindstone 11 relative to each other. In this embodiment, the grinder 1 is a cylindrical grinder. Moreover, the workpiece W has a cylindrical shape in this embodiment. The workpiece W is made of metal or ceramic, for example. The shape and material of the work W are not limited to these.

FIG. 1 depicts an X-axis and a Y-axis as mutually orthogonal axes. The X-axis and the Y-axis are horizontal axes when the grinding machine 1 is placed on a horizontal installation surface such as a floor. The X direction along the X axis is the width direction of the grindstone 11 . The Y direction is the direction along which the dresser 30 is cut in the dressing step (step S1) described later. The directions along the X-axis and the Y-axis, whether positive or negative, are defined as the width direction X and the cutting direction Y, respectively.

The grinder 1 includes a grindstone repairing device for executing the grindstone repairing method of the present embodiment. The grinding machine 1 includes a bed 2 , a wheelhead 10 , a Y-axis feeder 50 , a workpiece supporter 20 , an X-axis feeder 60 , a dresser 30 and a controller 40 .

The bed 2 supports each component 10 , 20 , 30 , 50 , 60 of the grinding machine 1 . The bed 2 has multiple surfaces. The bed 2 is made of cast iron, for example.

A wheelhead 10 is supported by a portion of the bed 2 . The grindstone head 10 includes a grindstone 11 and a grindstone shaft 12 . The grindstone table 10 supports a grindstone 11 , a grindstone shaft 12 , and a grindstone rotation drive device 15 . The wheelhead 10 is guided and supported on guardrails. The wheelhead 10 is also connected to a Y-axis feeder 50 . The Y-axis feeder 50 includes a Y-axis motor 51 . A Y-axis motor 51 provides driving force to the Y-axis feeder 50 . The Y-axis feeder 50 allows the wheelhead 10 to move in the cutting direction Y. As shown in FIG.

The grindstone 11 grinds the surface of the work W. As shown in FIG. The whetstone 11 is composed of a core 111 and a whetstone layer 112 . In this embodiment, the core 111 is a metal core made of a material such as iron and formed into a disc shape. The core 111 is detachably connected to the grindstone shaft 12 by a bolt or the like (not shown). The grindstone layer 112 forms a grinding surface 112f on the outer periphery, which contacts the workpiece W during grinding. The grindstone layer 112 has a configuration in which, for example, a large number of alumina-based abrasive grains G are bonded to the outer periphery of the core 111 with a bonding material K such as vitrified bond or resin bond. Specifically, the grindstone layer 112 is formed by mixing the abrasive grains G and the binder K and baking them. In this embodiment, the average abrasive grain size of the abrasive grains G is about 100 μm. In this embodiment, the grindstone layer 112 is formed in a disc shape and is a so-called grinding wheel provided so as to have a larger diameter than the core 111 . In the following, of the outer peripheral portion of the grindstone 11, the portion having the maximum diameter in the cutting direction Y is defined as the outer peripheral surface 112g. Also, a portion which is formed by grinding the outer peripheral surface 112g in a dressing step (step S1) to be described later and contacts the work W and the dresser 30 to be described later is defined as a ground surface 112f. That is, the ground surface 112f is a surface that forms a groove recessed from the outer peripheral surface 112g. The shape of the grindstone 11 and the configuration of the grindstone base 10 are not limited to these.

The grindstone shaft 12 rotatably supports the grindstone 11 . The grindstone shaft 12 is rotatably supported by the grindstone head 10 via bearings (not shown). The grindstone shaft 12 forms a grindstone rotation axis O<b>1 that is the rotation axis of the grindstone 11 . In this embodiment, the direction in which the grindstone rotation axis O1 extends is the horizontal direction. The direction in which the grindstone rotation axis O1 extends coincides with the width direction X. As shown in FIG.

The grindstone rotation drive device 15 rotates the grindstone shaft 12 at a predetermined number of revolutions. As a result, the grindstone 11 rotates around the grindstone rotation axis O1. The grindstone rotation drive device 15 includes a motor (not shown). The grindstone rotation drive device 15 and the grindstone shaft 12 are connected. The rotation speed of the grindstone 11 is controlled by the rotation speed of the motor of the grindstone rotation drive device 15 .

The work support device 20 supports both ends of the work W in the width direction X so as to be rotatable around the work rotation axis O2, which is the rotation axis of the work W. As shown in FIG. In this embodiment, the direction in which the work rotation axis O2 extends is the horizontal direction. The direction in which the work rotation axis O2 extends coincides with the width direction X. As shown in FIG. The work supporting device 20 has a table 21, a headstock 22, a tailstock 23, a spindle rotation driving device 26, and a dresser holding portion 22a.

A table 21 is placed on the bed 2 and guided and supported on guard rails. The table 21 is connected to the X-axis feeder 60 . The X-axis feeder 60 includes an X-axis motor 61 . The X-axis motor 61 gives driving force to the X-axis feeder 60 . The X-axis feeder 60 allows the table 21 to move in the X direction.

The headstock 22 and the tailstock 23 are arranged facing the upper surface of the table 21 and support one end and the other end of the workpiece W, respectively. The headstock 22 includes a chuck 24 and a spindle 27 . The chuck 24 grips one end of the work W. As shown in FIG.

A spindle rotation drive device 26 is provided on the headstock 22 . The main shaft rotation drive device 26 rotates the main shaft 27 at a predetermined number of revolutions. Specifically, a main shaft rotation drive device 26 applies a driving force to the main shaft 27, thereby causing the main shaft 27 to rotate. As a result, the work W rotates around the work rotation axis O2 via the chuck 24 . The spindle rotation drive device 26 includes a motor (not shown). The rotation speed of the workpiece W is controlled by, for example, the number of rotations of a motor (not shown) of the spindle rotation drive device 26 .

The tailstock 23 has a center 25 . The tailstock 23 is provided on the other end side of the work W in the width direction X so as to face the headstock 22 . The center 25 grips the other end of the work W. As shown in FIG. The tailstock 23 rotatably supports the other end of the work W at the center 25 . Specifically, one end of the center 25 contacts the other end of the work W to grip the work W. As shown in FIG. The work W is rotatably supported by the chuck 24 and the center 25 about the work rotation axis O2 parallel to the moving direction (width direction X) of the table 21 and is driven to rotate by the main shaft rotation drive device 26 .

The dresser holding portion 22a is guided and supported on the guardrail, and is provided at a position where the dresser 30 can come into contact with the grindstone 11 when moved in the width direction X along the guardrail. The dresser holding portion 22a fixes and holds the dresser 30 . The dresser holding portion 22a is driven by the X-axis motor 61 and becomes movable in the width direction X. As shown in FIG. When the dressing process (step S1) and the loose abrasive grain removing process (step S2) described later are not being performed, the dresser holding part 22a is positioned around the work W as shown in FIG. and the work W face each other and are arranged in a region other than the region where the grinding process is performed.

The dresser 30 is a tool for correcting the outer peripheral surface 112g of the grindstone 11 by cutting the outer peripheral surface 112g in a dressing step (step S1) described later. The dresser 30 is also a tool for removing free abrasive grains G1, which are attached to the grinding surface 112f of the grindstone 11, in the free abrasive grain removing step (step S2), which will be described later. In this embodiment, the dresser 30 is a single stone dresser. The dresser 30 is composed of a supporting member 31 and a single diamond stone 32 . The support member 31 is a member that supports the single diamond stone 32, and is detachably fixed to the dresser holding portion 22a. The single diamond stone 32 is a grindstone correcting member for grinding the outer peripheral surface 112g. The tip of the single diamond stone 32 is referred to as the tip 32a of the dresser 30 below.

The control device 40 performs numerical control by executing a machining program to control the grinding of the workpiece W, the dressing process (step S1) and the loose abrasive grain removing process (step S2), which will be described later. In this embodiment, the control device 40 is a CNC control device configured using a computer having a CPU, ROM, RAM, hard disk, and the like. The control device 40 is electrically connected to the grindstone rotation drive device 15, the spindle rotation drive device 26, the Y-axis feeder 50, and the X-axis feeder 60, respectively. Further, the control device 40 is connected to various sensors (not shown), processes signals from the sensors, and controls driving of the components 15, 26, 50, and 60 described above. Note that the control device 40 is not limited to this. The control device 40 only needs to be able to control the constituent elements 15, 26, 50, 60, etc. of the grinding machine 1, and may additionally include other constituent elements. The control device 40 may include, for example, an input device (not shown) for inputting a machining program, etc., and an output device (not shown) for outputting the processing content, processing status, and the like of the control device 40 . Also, at least some functions of the control device 40 may be configured by a hardware circuit.

On the premise of the grinder 1 described above, the grindstone repairing method of the present embodiment will be described. FIG. 2 is a flow chart showing the flow of the method for correcting the whetstone. FIG. 3 is a flow chart showing the flow of the loose abrasive grain removing step (step S2) in the grindstone repairing method. The grindstone repairing method, as shown in FIG. 2, includes a dressing step (step S1) and a loose abrasive grain removing step (step S2).

FIG. 4 is a diagram for explaining the grindstone repairing method according to the first embodiment. FIG. 4 schematically shows the positional relationship between the grindstone 11 and the dresser 30 . In FIG. 4, by drawing the abrasive grains G as large as possible, the length (width) of the grindstone layer 112 in the width direction X and the length (thickness) of the grindstone layer 112 in the cutting direction Y are only partially Illustrated. The left diagram of FIG. 4 shows the positional relationship between the grindstone 11 and the dresser 30 before the dressing step (step S1) is performed. 4 shows the positional relationship between the grindstone 11 and the dresser 30 after the dressing step (step S1) and before the loose abrasive grain removing step (step S2). The right diagram of FIG. 4 also shows free abrasive grains G1, which will be described later. FIG. 5 is an enlarged view of region R1 in FIG. First, the dressing step (step S1) will be described below with reference to the left diagram of FIG.

In the dressing step (step S1), the outer peripheral surface 112g of the grindstone 11 is shaved by a single diamond stone 32, which is a tip of the dresser 30 and has a length C1 in the width direction X, so that the grindstone layer 112 of the grindstone 11 includes This is the step of forming the ground surface 112f on the plurality of abrasive grains G. FIG. The length C1 is the length of the portion of the tip of the dresser 30 that contributes to grinding. FIG. 4 schematically illustrates a representative portion of the abrasive grains G among the plurality of abrasive grains G contained in the grindstone layer 112 . In the dressing step (step S1), the dresser 30 cuts the outer peripheral surface 112g of the grindstone 11 rotating at a predetermined rotation speed r [rpm] per minute with a predetermined cutting amount LD. Specifically, first, the dresser 30 is moved in the width direction X and arranged at a position close to the grindstone 11 . In this state, by moving the grindstone 11 in the cutting direction Y toward the dresser 30 (-Y direction), the dresser 30 moves in the +Y direction, which is the direction toward the grindstone shaft 12 from the outer peripheral surface 112g of the grindstone 11. cut in. That is, in the present embodiment, the position of the dresser 30 in the cutting direction Y does not move, and the grindstone 11 moves in the cutting direction Y, thereby changing the relative positional relationship between the dresser 30 and the grindstone 11 in the cutting direction Y. Let At the start of the dressing step (step S1), as indicated by the solid line in the left diagram of FIG. , is located on the side of one end 112a in the width direction X of the grindstone 11. As shown in FIG. The depth of cut LD in the dressing step (step S1) is arbitrary. In this embodiment, the depth of cut LD is 10 μm, which is about 1/10 of the average abrasive grain size of the abrasive grains G, which is about 100 μm.

Subsequently, the outer peripheral surface 112g is ground by moving (traversing) the dresser 30 once in the width direction X at a preset moving speed v with respect to the rotating grindstone 11 . That is, the dresser 30 moves in the width direction X by the dresser movement distance D1 while the grindstone 11 rotates once. The dresser movement distance D1 is approximately the same as the length C1 in the width direction X of the single diamond stone 32 in the dresser 30 . Specifically, the dresser 30 is moved from the one end 112a side in the width direction X toward the other end 112b side in a state in which the outer peripheral surface 112g is cut. At the end of the dressing step (step S1), as shown by the dotted line in the left diagram of FIG. It is positioned on the side of the other end 112b in the width direction X of the grindstone 11 in this state. Thus, the dresser 30 is cut into the outer peripheral surface 112g and moved in the width direction X. As shown in FIG. As a result, the outer peripheral surface 112g of the grindstone 11 has a predetermined rotational speed r [rpm] of the grindstone 11 per minute, a moving speed v for moving (traversing) the dresser 30 in the width direction X with respect to the grindstone 11, It is dressed (grindstone correction) so that it becomes the desired surface roughness obtained by.

Here, in the dressing step (step S1), since the outer peripheral surface 112g of the grindstone 11 is ground by the dresser 30, loose abrasive grains G1 as the ground grindstone are generated on the grinding surface 112f. If the workpiece W is ground without removing the free abrasive grains G1, the surface of the workpiece W to be ground may be scratched. Therefore, in the grindstone repairing method of the present embodiment, the free abrasive grain removal step (step S2) shown below is executed after the dressing step (step S1), thereby removing the free abrasive grains G1 from the grinding surface 112f of the grindstone 11. to remove

In this embodiment, the dresser 30 is positioned on the side of the other end 112b in the width direction X of the grindstone 11 at the end of the dressing step (step S1). In this embodiment, before starting the loose abrasive grain removal step (step S2), the dresser 30 is returned to the position at the start of the dressing step (step S1). The removal step (step S2) is started. Also, for ease of understanding, only a portion of the large number of free abrasive grains G1 attached to the grinding surface 112f is shown representatively in the right diagram of FIG.

The loose abrasive grain removing step (step S2) performed after the dressing step (step S1) will be described below with reference to FIGS. 3 to 5. FIG. As shown in FIG. 3, the loose abrasive grain removal step (step S2) has a dresser position determination step (step S22) and a traverse step (step S24). In the free abrasive grain removal step (step S2), the dresser 30 is moved in the width direction X with respect to the grindstone 11 at a moving speed v This is done by moving (traversing) with .

As shown in FIGS. 4 and 5, in the dresser position determination step (step S22), the grindstone 11 is moved away from the dresser 30, thereby moving the dresser 30 relative to the −Y direction within a range of less than the depth of cut LD. backwards. First, as shown in FIG. 5, a retreat distance L1, which is a distance by which the dresser 30 is relatively retreated in the -Y direction within a range of less than the depth of cut LD, is determined. A method for determining the retreat distance L1 will be described below.

The dresser 30 and the grinding surface 112f must be provided at positions where the free abrasive grains G1 and the dresser 30 can come into contact with each other during the process of moving the dresser 30 in the width direction X in the traverse step (step S24). That is, the receding distance L1 should be less than the size of the free abrasive grains G1.

At this time, it is conceivable that the free abrasive grains G1 form various shapes. In the present embodiment, for ease of understanding, as shown in FIG. 4, the free abrasive grains G1 are assumed to have a nearly circular shape in cross-sectional view.

Here, the free abrasive grains G1 are chips generated when the outer peripheral surface 112g is scraped off in the cutting direction Y by the length of the cutting depth LD in the dressing step (step S1). Therefore, it is considered that the average abrasive grain size of the free abrasive grains G1 is about the size obtained by multiplying the depth of cut LD by 0.7 to 0.9. For this reason, in the process of moving the dresser 30 in the width direction X in the traverse step (step S24), the retraction distance L1 for bringing the free abrasive grain G1 and the dresser 30 into contact with each other is set to be less than the depth of cut LD. Any range is acceptable. 4 and 5 illustrate the case where the tip 32a of the dresser 30 is located at a position where the receding distance L1 is less than the depth of cut LD and greater than half the depth of cut LD.

Thus, the retreat distance L1 is determined. Further, the dresser 30 is relatively retracted in the -Y direction so that the determined retraction distance L1 is achieved. Specifically, by moving the grindstone 11 away from the dresser 30 (+Y direction), the dresser 30 is relatively retreated by the retreat distance L1. The grinding surface 112f is a spiral groove formed on the outer circumference of the grindstone 11. As shown in FIG. The width of the spiral groove becomes narrower toward the inner side, which is the side closer to the grindstone shaft 12 in the cutting direction Y, in the grinding surface 112f. Since the free abrasive grains G1 have a diameter, they tend to adhere to the front side of the spiral groove, which is opposite to the back side, rather than the back side. It is desirable that the dresser 30 also pass during the loose abrasive grain removing step (step S2) following the spiral groove formed during the dressing step (step S1). However, the position of the dresser 30 is shifted in the width direction of the groove in most cases. When the position of the dresser 30 shifts in the width direction of the groove, if the retreat distance L1 is small, the amount of free abrasive grains G1 that can be removed increases, but the amount of dressing the ground surface 112f increases. If the receding distance L1 is large, the amount of free abrasive grains G1 that can be removed is reduced, but the amount of dressing the ground surface 112f is also reduced.

Next, as shown in FIG. 4, in the traverse step (step S24), the dresser 30 is moved (traversed) in the width direction X with respect to the rotating grindstone 11 to drop and remove the loose abrasive grains G1. . Here, the free abrasive grains G1 are simply adhered onto the grinding surface 112f. In other words, the free abrasive grains G1 fall off the ground surface 112f when physically brought into contact with another object. Therefore, in the traverse step (step S24), in the process of moving the dresser 30 in the width direction X, it is brought into contact with the loose abrasive grains G1 on the grinding surface 112f. As a result, the free abrasive grains G1 are removed from the grinding surface 112f by the dresser 30, thereby removing the free abrasive grains G1 on the grinding surface 112f.

Here, in the traverse step (step S24), the disk-shaped grindstone 11 is rotating. Therefore, in the traverse step (step S24), in order to bring the dresser 30 into contact with the free abrasive grains G1 adhering to the grinding surface 112f of the rotating grindstone 11, the dresser must It is preferable to set the distance that 30 moves to the same extent or less as in the dressing step (step S1). Hereinafter, in the traverse step (step S24), the distance that the dresser 30 moves in the width direction X during one rotation of the grindstone 11 is defined as a dresser movement distance D1. A method for determining the dresser movement distance D1 will be described below.

The free abrasive grains G1 adhere to various portions of the grinding surface 112f of the grindstone 11. As shown in FIG. Consider a case where the dresser movement distance D1 is not appropriate. For example, assume that the dresser movement distance D1 is set to be the same distance as the length of the grindstone 11 in the width direction X as a case where the dresser movement distance D1 is extremely long. In this case, the dresser 30 moves from one end 112a to the other end 112b of the grindstone 11 while the grindstone 11 rotates once. At this time, when the dresser movement distance D1 during one revolution of the grindstone 11 is set to be equal to or greater than the average abrasive grain size of the free abrasive grains G1, the dresser 30 reaches the other end 112b of the grindstone 11 before coming into contact with the free abrasive grains G1. do. That is, the dresser 30 reaches the other end 112b of the grindstone 11 without reliably removing the free abrasive grains G1 adhering to the grinding surface 112f. On the other hand, the average abrasive grain size of the free abrasive grains G1 is about the depth of cut LD multiplied by 0.7 to 0.9. Therefore, in the loose abrasive grain removal step (step S2), the dresser movement distance D1 per rotation of the grindstone 11 can be set to be the same as the dresser movement distance D1 per rotation of the grindstone 11 in the dressing step (step S1). desirable. In this case, the receding distance L1 is preferably 0.5 times or more and 0.6 times or less of the depth of cut LD. Here, as shown in FIG. 5 , the end on the far side in the cutting direction Y of the grooves (ground surface 112f) formed on the outer peripheral surface 112g is defined as a bottom portion B. As shown in FIG. The front end coincides with the outer peripheral surface 112g. The center of the free abrasive grains G1 is located between the groove (grinding surface 112f) formed in the outer peripheral surface 112g of the grindstone 11 and the portion extending from the outer peripheral surface 112g to the bottom B side by 1/2 LD and the outer peripheral surface 112g. exists in When the dresser moving distance D1 in the loose abrasive grain removing step (step S2) is set to half the dresser moving distance D1 in the dressing step (step S1), the receding distance L1 is preferably three quarters of the depth of cut. .

According to the above embodiment, the free abrasive grains G1 generated by grinding the outer peripheral surface 112g of the grindstone 11 with the dresser 30 in the dressing step (step S1) are removed in the free abrasive grain removing step (step S2). As a result, since the free abrasive grains G1 on the grinding surface 112f are removed by the dresser 30, when the workpiece W as the object to be ground is ground after executing the grinding wheel correction method, It is possible to reduce the occurrence of scratches.

Further, according to the above-described embodiment, after the dressing step (step S1), the dresser 30 is retracted relative to the grindstone 11 within a range of less than the depth of cut LD. is moved in the width direction X, the free abrasive grains G1 can be removed by the dresser 30 . That is, by changing the relative positional relationship between the dresser 30 and the grinding surface 112f in the process of performing the dressing step (step S1) and the free abrasive grain removing step (step S2), the free abrasive grains G1 are removed by the dresser 30. can be removed. Therefore, the dressing step (step S1) to the loose abrasive grain removing step (step S2) can be performed in a continuous series of steps without executing another step using a separate member for removing the loose abrasive grains G1. . As a result, the time required for correcting the whetstone can be shortened. Moreover, since a separate member for removing the free abrasive grains G1 is not required, the unit price of the product can be reduced.

Further, according to the above embodiment, in the dresser position determination step (step S22), the retreat distance L1 and the dresser movement distance D1 are determined, and then the traverse step (step S24) is executed. As a result, the free abrasive grains G1 on the grinding surface 112f of the rotating grindstone 11 can be efficiently removed.

Furthermore, in the above embodiment, the retreat distance L1 can be set to 0.5 times or more and 0.6 times or less of the depth of cut LD. This can further improve the probability of contact between the dresser 30 and the free abrasive grains G1 in the free abrasive grain removing step (step S2). In other words, even if the dresser 30 moves only once in the width direction X in the traverse step (step S24), the loose abrasive grains G1 on the grinding surface 112f can be more reliably removed.

B. Second embodiment:
FIG. 6 is a diagram for explaining the grindstone repairing method according to the second embodiment. FIG. 6 schematically shows the positional relationship between the grindstone 11 and the impregnated dresser 80 . In FIG. 6, by drawing the abrasive grains G as large as possible, the length (width) of the grindstone layer 112 in the width direction X and the length (thickness) of the grindstone layer 112 in the cutting direction Y are only partially Illustrated. The left diagram of FIG. 6 shows the positional relationship between the grindstone 11 and the impregnated dresser 80 before the dressing step (step S1) is performed. The right diagram of FIG. 6 shows the positional relationship between the grindstone 11 and the impregnated dresser 80 after the dressing step (step S1) and before the loose abrasive grain removing step (step S2). The right figure of FIG. 6 also shows loose abrasive grains G1. In the right diagram of FIG. 6, for ease of understanding, only a portion of the large number of free abrasive grains G1 adhering to the grinding surface 112f is representatively illustrated, as in the right diagram of FIG. Note that the shape of the loose abrasive grains G1 is not limited to the present disclosure. The impregnated dresser 80 described in the present embodiment can also be applied to loose abrasive grains having a shape close to a triangle in cross-sectional view and loose abrasive grains having various other shapes.

In this embodiment, instead of the dresser 30 as a single stone dresser, a wide implied dresser 80 is used. Implied dresser 80 is a tool having the same function as dresser 30 . The implied dresser 80 has a length C2 in the width direction X on the tip side facing the outer peripheral surface 112g, which is X times (where X is a number greater than 1) that of the single stone dresser. That is, the implied dresser 80 is a tool for correcting the outer peripheral surface 112g of the grindstone 11 by cutting the outer peripheral surface 112g in the dressing step (step S1), and grinds the grindstone 11 in the free abrasive grain removal step (step S2). It is also a tool for removing free abrasive grains G1 adhering to the surface 112f. The impredresser 80 is composed of a shank 81 as a support member and a tip 82 as a grindstone correcting member.

The tip 82 is a grinding wheel correction member in which a large number of abrasive grains are bonded with a bonding material, and grinds the outer peripheral surface 112g. The abrasive grains contained in the tip 82 are, for example, diamond abrasive grains. The tip 82 has a length C2 in the width direction X. As shown in FIG. The tip 82 has a tip portion 82a facing the outer peripheral surface 112g. A tip portion 82a of the tip 82 is in a state in which a portion of a large number of abrasive grains contained in the tip 82 protrudes. The outer peripheral surface 112g of the grindstone 11 is dressed (grindstone correction) by grinding the outer peripheral surface 112g with the projected portion of the many abrasive grains contained in the tip 82 . The shank 81 is a supporting member that supports the chip 82 and is detachably fixed to the dresser holding portion 22a. The proximal end of tip 82 is attached to shank 81 .

Note that the configuration of the device in this embodiment is the same as that in the first embodiment shown in FIG. 1, so description thereof will be omitted. The grindstone repairing method of this embodiment includes a dressing step (step S1) and a loose abrasive grain removing step (step S2), as in the first embodiment shown in FIG. Further, the loose abrasive grain removal step (step S2) in this embodiment includes a dresser position determination step (step S22) and a traverse step (step S24), as in the first embodiment shown in FIG. This embodiment differs from the first embodiment in that an impregnated dresser 80 is used in the grinding wheel correction, and in that the dresser moving distance D2 is different in the dressing process (step S1) and the loose abrasive grain removal process (step S2). . The method for correcting the grindstone of this embodiment using the impregnated dresser 80 will be described below. Note that the dressing step (step S1) (left diagram in FIG. 6) and the dresser position determination step (step S22) in the present embodiment are the same as those in the first embodiment (FIG. 4), and thus description thereof is omitted.

In the dressing step (step S1) and the loose abrasive grain removing step (step S2), when using the implied dresser 80 with the tip 82 (length C2), the dresser 30 with the single diamond stone 32 (length C1) is used. It differs from the case of using it in the following points. When using the impregnated dresser 80, the portion in contact with or facing the ground surface 112f is longer than when the dresser 30 is used, by the length C2-C1 in the width direction X. FIG. Therefore, when the impregnated dresser 80 is moved in the width direction X while facing the outer peripheral surface 112g, it is possible to increase the movement distance by the length C2-C1 as compared with the case where the dresser 30, which is a single stone dresser, is used. can. Therefore, if Y is the dresser moving distance when the dressing step (step S1) and the loose abrasive grain removing step (step S2) are performed using the dresser 30 as a single-stone dresser, the following displacement is obtained. Just do it. The dresser moving distance D2 when performing the dressing step (step S1) and the loose abrasive grain removing step (step S2) using the impregnated dresser 80 may be X times Y. For example, an implied dresser 80 in which three diamond single stones 32 with a length C1 are arranged in the width direction X and equipped with a tip 82 with a length C2 (in this case, C2=C1×3) is used. Consider the case. In this case, in the dressing step (step S1) and the loose abrasive grain removing step (step S2), the dresser 30 is used for the dresser movement distance D2 when moving the impregnated dresser 80 in the width direction X with respect to the rotating grindstone 11. It is preferable to determine a value obtained by multiplying the dresser moving distance D1 by 3. The manner of movement of the impregnated dresser 80 and the grindstone 11 in the traverse step (step S24) is the same as that of the first embodiment described with reference to the right diagram of FIG. The number of spiral grooves formed on the outer peripheral surface 112g matches the number of abrasive grains exposed at the tip 82a of the tip 82. As shown in FIG. For example, in the dressing step (step S1), when using the implied dresser 80 in which three single diamond stones 32 are arranged in the width direction X, a triple spiral groove is formed in the outer peripheral surface 112g.

Also in the above embodiment, free abrasive grains G1 generated by grinding the outer peripheral surface 112g of the grindstone 11 with the impregnated dresser 80 in the dressing step (step S1) are removed in the free abrasive grain removing step (step S2). As a result, since the free abrasive grains G1 on the grinding surface 112f are removed by the impredresser 80, when the work W as the grinding object is ground after executing the grinding wheel correction method, the surface to be ground of the work W is The occurrence of scratches can be reduced.

Further, even in the above-described embodiment, after the dressing step (step S1), the impregnated dresser 80 is relatively retreated with respect to the grindstone 11 within a range of less than the depth of cut LD, and then the rotating grindstone 11 is By moving the impregnated dresser 80 in the width direction X, the impregnated abrasive grains G1 can be removed by the impregnated dresser 80 . That is, in the process of performing the dressing step (step S1) and the free abrasive grain removing step (step S2), by changing the relative positional relationship between the impre-dresser 80 and the grinding surface 112f, the im pre-dresser 80 Grain G1 can be removed. Therefore, the dressing step (step S1) to the loose abrasive grain removing step (step S2) can be performed in a continuous series of steps without executing another step using a separate member for removing the loose abrasive grains G1. . As a result, the time required for correcting the whetstone can be shortened. Moreover, since a separate member for removing the free abrasive grains G1 is not required, the unit price of the product can be reduced.

Also in the above embodiment, the retreat distance L1 and the dresser movement distance D2 are determined in the dresser position determination step (step S22), and then the traverse step (step S24) is executed. As a result, the free abrasive grains G1 on the grinding surface 112f of the rotating grindstone 11 can be efficiently removed.

Further, in the above embodiment, when the dresser movement distance when the dressing step (step S1) and the loose abrasive grain removing step (step S2) are performed using the dresser 30 as a single stone dresser is Y, , can be The dresser moving distance D2 when performing the dressing step (step S1) and the loose abrasive grain removing step (step S2) using the impregnated dresser 80 can be X times Y. That is, in the case of using the implied dresser 80, compared with the case of using the dresser 30 as a single stone dresser, it is possible to increase the moving distance of the grindstone 11 during one rotation in the width direction X by the length C2-C1. can. As a result, the time required from the start to the end of the traverse step (step S24) can be shortened, so the time required for correcting the grindstone can be shortened.

C. Other embodiments:
C-1. Alternative Embodiment 1:
In the above embodiment, either the dresser 30 or the impregnated dresser 80 moves in the width direction X once in the dressing step (step S1) and the loose abrasive grain removing step (step S2). However, the present disclosure is not limited to this. In the dressing step (step S1), the number of times one of the dresser 30 and the impregnated dresser 80 moves in the width direction X may be a plurality of times.

C-2. Alternative Embodiment 2:
In the above embodiment, either one of the dresser 30 and the impregnated dresser 80, which are single-stone dressers, is used to perform the dressing step (step S1) and the loose abrasive grain removing step (step S2). However, the dresser may be a single stone dresser or a dresser other than the implied dresser 80 . Another dresser may be, for example, a multi-stone dresser in which a plurality of diamonds are fixed to one supporting member 31 .

C-3. Alternative Embodiment 3:
In the above embodiments, the grinder 1 was a cylindrical grinder. However, the present disclosure is not limited to this. The grinder 1 may be another grinder such as an internal grinder, a centerless grinder, or a surface grinder.

C-4. Alternative Embodiment 4:
In the above embodiment, tools such as the dresser 30, the implied dresser 80, and other dressers (hereinafter referred to as dressers, etc.) do not move in the cutting direction Y, but move only in the width direction X. Further, the grindstone 11 moving together with the grindstone head 10 did not move in the width direction X, but moved only in the cutting direction Y. As a result, the positional relationship between the dresser or the like and the grinding surface 112f of the grindstone 11 is relatively changed. However, the present disclosure is not limited to this. The dresser 30 and the like may be provided so as to be movable in both the width direction X and the cutting direction Y.

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the scope of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each form described in the outline of the invention are used to solve some or all of the above problems, or Alternatively, replacements and combinations can be made as appropriate to achieve all. Also, if the technical features are not described as essential in this specification, they can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 1... Grinding machine, 2... Bed, 10... Grindstone head, 11... Grindstone, 12... Grindstone shaft, 15... Grindstone rotation drive device, 20... Work support device, 21... Table, 22... Headstock, 22a... Dresser holding part , 23... Tailstock, 24... Chuck, 25... Center, 26... Spindle rotation drive device, 27... Main spindle, 30... Dresser, 31... Support member, 32... Diamond single stone, 32a... Tip, 40... Control device, 50 Y-axis feeder 51 Y-axis motor 60 X-axis feeder 61 X-axis motor 80 Impli dresser 81 Shank 82 Tip 82a Tip 111 Core 112 Grindstone layer 112a...one end 112b...other end 112f...grinding surface 112g...peripheral surface B...bottom C1, C2...length D1, D2...dresser movement distance G...abrasive grain G1...free abrasive grain, K... binder, L1... setback distance, LD... depth of cut, O1... grindstone rotation axis, O2... work rotation axis, R1... area, S1... dressing process, S2... loose abrasive grain removal process, S22... dresser position Determining step S24 Traverse step v Moving speed W Workpiece X Width direction Y Cutting direction

Claims (5)

A method for correcting a whetstone,
Dressing for forming a grinding surface on the outer peripheral surface of the grindstone by cutting the outer peripheral surface of the rotating grindstone with a dresser by a predetermined cutting amount and moving the dresser in the width direction of the grindstone to grind the outer peripheral surface. process and
After the dressing step, the dresser is moved in the width direction after relatively retreating the dresser with respect to the grindstone in a range of less than the depth of cut, so that the ground surface generated in the dressing step and a free abrasive grain removing step of removing free abrasive grains from the grinding wheel. The whetstone repairing method according to claim 1,
In the free abrasive grain removing step, the dresser movement distance, which is the distance that the dresser moves in the width direction while the grindstone makes one rotation, is the distance that the dresser moves in the width direction while the grindstone makes one rotation in the dressing step. The wheel correction method, which is the same as the distance moved in the direction. The whetstone repairing method according to claim 2,
The grinding wheel repairing method, wherein in the loose abrasive grain removing step, a distance for relatively retreating the dresser is 0.5 times or more and 0.6 times or less of the depth of cut. The whetstone repairing method according to claim 2 or 3,
The grindstone repairing method, wherein the dresser is a single-stone dresser. The whetstone repairing method according to claim 4,
The dresser is an implied dresser having a width X times (where X is a number greater than 1) the length of the single-stone dresser in the width direction on a tip side facing the outer peripheral surface,
When the dressing step and the loose abrasive grain removing step are performed using the single-stone dresser and the dresser moving distance is Y, the dressing step and the loose abrasive grain removing step are performed using the implime dresser. The dresser movement distance when executing is X times the Y, the grindstone correcting method.

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