阅读说明：本技术 砂轮的修整方法以及砂轮的修正装置 (Method for dressing grinding wheel and grinding wheel dressing device ) 是由 渡边明 于 2020-04-21 设计创作，主要内容包括：砂轮的修整方法具备：使上述砂轮旋转的步骤、在上述旋转过程中使上述砂轮的外周的磨削面与修整工具抵接的步骤、在上述旋转过程中使上述砂轮与上述修整工具向上述砂轮的砂轮宽度方向相对移动的步骤,上述修整方法进一步具备：测定上述修整工具相对于上述砂轮的上述砂轮宽度的上述修整工具磨损量的步骤；以及使用上述修整工具磨损量,作为进刀方向的进刀量,根据上述砂轮与上述修整工具的上述砂轮宽度方向的相对移动,使上述砂轮与上述修整工具向上述进刀方向相对移动,由此修整上述砂轮的步骤。(The dressing method of the grinding wheel comprises the following steps: a step of rotating the grindstone, a step of bringing a grinding surface of an outer periphery of the grindstone into contact with a dresser during the rotation, and a step of relatively moving the grindstone and the dresser in a grindstone width direction of the grindstone during the rotation, the dressing method further including: measuring an amount of wear of the dressing tool with respect to the grinding wheel width of the grinding wheel; and dressing the grinding wheel by relatively moving the grinding wheel and the dressing tool in the cutting direction based on the relative movement of the grinding wheel and the dressing tool in the grinding wheel width direction, using the dressing tool wear amount as the cutting feed amount in the cutting direction.)

1. A dressing method of a grinding wheel, the dressing method comprising:

a step of rotating the grinding wheel,

A step of bringing a grinding surface of an outer periphery of the grinding wheel into contact with a dressing tool during the rotation, and

a step of relatively moving the grinding wheel and the dressing tool in a grinding wheel width direction of the grinding wheel during the rotation,

the trimming method further includes:

measuring a wear amount of the dressing tool with respect to the grinding wheel width of the grinding wheel;

using the dressing tool wear amount as a feed amount in a feed direction, and relatively moving the grinding wheel and the dressing tool in the feed direction in accordance with the relative movement of the grinding wheel and the dressing tool in the grinding wheel width direction, thereby dressing the grinding wheel.

2. Finishing method according to claim 1,

further comprising a step of calculating a feed speed, which is a relative movement speed in the feed direction, based on the dressing tool wear amount and a predetermined width direction speed, which is a relative movement speed in the width direction of the grinding wheel,

the dressing step includes a step of relatively moving the grinding wheel and the dressing tool in the grinding wheel width direction at the width direction speed and relatively moving the grinding wheel and the dressing tool in the cutting direction at the cutting feed speed.

3. Finishing method according to claim 1 or 2,

the determination of the wear amount has:

a step of preliminarily dressing the grinding wheel without relatively moving the grinding wheel and the dressing tool in the feed direction,

A step of machining a reference surface parallel to the grinding wheel width direction on the workpiece,

A step of forming a transfer groove by transferring a grindstone shape of the grindstone to the reference surface of the workpiece, and

a step of measuring the straightness of the transfer groove formed by the transfer,

the straightness obtained by the measurement of the straightness corresponds to the dressing tool wear amount.

4. Finishing method according to claim 1 or 2,

the determination of the wear amount has:

a step of preliminarily dressing the grinding wheel without relatively moving the grinding wheel and the dressing tool in the feed direction, and

measuring heights of the grinding wheel in a radial direction at both ends of the grinding surface of the grinding wheel in the grinding wheel width direction after the preparatory dressing,

the difference between the heights at the both ends in the grinding wheel width direction obtained by the height measurement corresponds to the dressing tool wear amount.

5. The finishing method according to any one of claims 1 to 4,

the dressing tool has a diamond single stone dressing tool including a diamond single stone fixed and held at a leading end,

the dressing tool wear amount corresponds to the wear amount of the diamond whetstone.

6. A dressing apparatus for dressing a grinding wheel, comprising:

the grinding wheel is rotatably arranged,

Dressing tool, and

a control part for controlling the operation of the display device,

the dressing device is configured to rotate the grinding wheel, to bring a grinding surface of an outer periphery of the grinding wheel into contact with the dressing tool during the rotation, and to relatively move the grinding wheel and the dressing tool in a grinding wheel width direction of the grinding wheel during the rotation, thereby dressing the grinding wheel,

the control unit uses a dressing tool wear amount, which is a wear amount of the dressing tool in the grinding wheel width direction with respect to the grinding wheel, as a feed amount in a feed direction

The control unit is configured to relatively move the grinding wheel and the dresser in the cutting direction in accordance with the relative movement of the grinding wheel and the dresser in the grinding wheel width direction, thereby dressing the grinding wheel.

7. Correction device according to claim 6,

the dressing tool machining apparatus further includes a feed speed calculation unit configured to calculate a feed speed, which is a relative movement speed in the feed direction, based on the dressing tool wear amount and a predetermined width direction speed, which is a relative movement speed in the grinding wheel width direction,

the control unit is configured to move the grinding wheel and the dressing tool relative to each other in the grinding wheel width direction at the width direction speed and to move the grinding wheel and the dressing tool relative to each other in the cutting direction at the cutting feed speed.

8. Correction device according to claim 6 or 7,

the dressing tool has a diamond single stone dressing tool including a diamond single stone fixed and held at a leading end,

the dressing tool wear amount corresponds to the wear amount of the diamond whetstone.

Technical Field

The present invention relates to a method of dressing a grinding wheel and a grinding wheel truing apparatus.

Background

Conventionally, grinding wheels have been used as machining tools in grinding machines. Since the grinding surface of the grinding wheel is worn and deformed in association with the machining of the workpiece, the grinding surface is regenerated by dressing with a dressing tool such as a diamond dressing tool after a predetermined amount of the workpiece is machined (see, for example, japanese patent application laid-open No. 2007-175815).

However, the diamond gradually wears and becomes shorter in the process of dressing the grinding wheel in the width direction of the grinding wheel by the diamond dresser, and the grinding surface of the grinding wheel may be inclined in the width direction, so that one corner portion may be higher in the radial direction than the other corner portion. Further, when a workpiece is ground using a grinding wheel having an inclined grinding surface, one corner portion strongly abuts against the workpiece, and thus there is a problem that a feed mark is generated on the surface of the workpiece.

Disclosure of Invention

The invention provides a grinding wheel dressing method and a grinding wheel dressing device, which can eliminate the influence of abrasion of a dressing tool along with dressing and regenerate a grinding surface parallel to the width direction of the grinding wheel.

According to one aspect of the present invention, a method for dressing a grinding wheel includes: the method includes a step of rotating the grinding wheel, a step of bringing a grinding surface of an outer periphery of the grinding wheel into contact with a dresser during the rotation, and a step of relatively moving the grinding wheel and the dresser in a grinding wheel width direction of the grinding wheel during the rotation.

The trimming method according to the above aspect further includes: measuring an amount of wear of the dressing tool with respect to the grinding wheel width of the grinding wheel; and dressing the grinding wheel by relatively moving the grinding wheel and the dressing tool in the cutting direction based on the relative movement of the grinding wheel and the dressing tool in the grinding wheel width direction, using the dressing tool wear amount as the cutting feed amount in the cutting direction.

According to this method, the amount of wear of the dresser with respect to the grinding wheel width of the grinding wheel is measured, the amount of wear of the dresser is used, and the grinding wheel and the dresser are relatively moved in the cutting direction in accordance with the relative movement of the grinding wheel and the dresser in the grinding wheel width direction as the amount of cutting, whereby the influence of wear of the dresser accompanying dressing is eliminated, and the grinding surface parallel to the grinding wheel width direction can be regenerated.

According to another aspect of the present invention, a grinding wheel truing device includes: the grinding wheel, the dressing tool, and the control unit are provided to be rotatable. The dressing device is configured to rotate the grindstone, to bring a grinding surface of an outer periphery of the grindstone into contact with the dressing tool during the rotation, and to relatively move the grindstone and the dressing tool in a grindstone width direction of the grindstone during the rotation, thereby dressing the grindstone.

The control unit of the correction device of the above aspect uses a dressing tool wear amount, which is a wear amount of the dressing tool with respect to the grinding wheel width of the grinding wheel, as a feed amount in a feed direction. The control unit is configured to relatively move the grinding wheel and the dresser in the cutting direction in accordance with the relative movement of the grinding wheel and the dresser in the grinding wheel width direction, thereby dressing the grinding wheel.

According to this configuration, the dressing tool wear amount, which is the wear amount of the dressing tool relative to the grinding wheel width of the grinding wheel, is used as the feed amount, and the grinding wheel and the dressing tool are relatively moved in the feed direction in accordance with the relative movement of the grinding wheel and the dressing tool in the grinding wheel width direction, whereby the influence of the wear of the dressing tool accompanying dressing is eliminated, and the grinding surface parallel to the grinding wheel width direction can be regenerated.

Drawings

Fig. 1 is a plan view showing the overall structure of a grinding machine according to an embodiment.

Fig. 2 is a flowchart showing a flow of a grinding wheel truing method according to an embodiment.

Fig. 3 is a flowchart showing a flow of a diamond wear amount measuring method according to an embodiment.

Fig. 4 is a schematic diagram showing a trimming process based on a related-art method.

Fig. 5 is a schematic diagram showing a reference surface processing step.

Fig. 6 is a schematic diagram showing a grinding wheel shape transfer process.

Fig. 7 is an enlarged schematic view of a grinding wheel-shaped transfer groove formed on the surface of a workpiece.

Fig. 8 is a schematic diagram showing the appearance of the grinding wheel at the start and end of dressing.

Detailed Description

Embodiments of a method for dressing a grinding wheel and a grinding wheel truing apparatus according to the present invention will be described below with reference to the accompanying drawings.

(1. integral structure of grinding machine)

The overall structure of a grinding machine 1 according to an embodiment of the present invention will be described with reference to fig. 1. The grinding machine 1 is a grinding wheel truing device for executing the method of truing a grinding wheel according to the present invention. Fig. 1 is a plan view showing the overall structure of the grinding machine 1. The grinding machine 1 is a machine tool that performs grinding by moving a grinding wheel 11 relative to a workpiece W supported by a base 2. The grinding machine 1 includes a wheel head 10, a Z-axis feeding device 50, a work support device 20, an X-axis feeding device 60, a dressing tool 30, and a control device 40.

The wheel head 10 has a wheel 11 and a wheel spindle 12. The wheel head 10 is provided with a wheel rotation driving device 15 for rotationally driving a grinding wheel 11 for grinding a workpiece W. The grinding wheel spindle 12 is a spindle of the grinding wheel 11 rotatably supported by the grinding wheel head 10 via a bearing and rotatably driven at a predetermined number of revolutions by the grinding wheel rotation driving device 15. The grinding wheel 11 is composed of a core portion 111 and a grinding wheel layer 112. In the present embodiment, the core 111 is a metal core made of iron or the like formed in a disc shape, and is detachably coupled to the wheel spindle 12 by a bolt or the like. The grinding wheel layer 112 is a portion where a grinding surface 112a that comes into contact with the workpiece W during grinding is formed on the outer periphery, and is configured such that abrasive grains of alumina, silicon carbide, or the like are bonded to the outer periphery of the core portion 111 with a binder (binder) such as a ceramic binder or a resin binder.

The grinding wheel head 10 is guided and supported by a guide rail, not shown, disposed on the upper surface of the base 2 and extending in a direction perpendicular to the central axis AW of the grinding wheel 11. The grinding wheel 11 is movable in a Z-axis direction (vertical direction in fig. 1) parallel to the upper surface of the base 2 and in the radial direction of the workpiece W by a Z-axis feed device 50 including a Z-axis motor 51 and a Z-axis ball screw (not shown). The Z-axis motor 51 and the grindstone rotation drive device 15 control the movement of the grindstone 11 in the Z-axis direction, the rotation speed of the grindstone 11, and the like by the control device 40.

The workpiece support device 20 supports both ends of the workpiece W so as to be rotatable about the central axis of the workpiece W. The workpiece support device 20 includes a table 21, a headstock 22, a tailstock 23, a chuck 24, and a center 25. The table 21 is disposed on the upper surface of the base 2 of the grinding machine 1 and is guided and supported by a guide rail, not shown, extending in the direction of the center axis AW of the grinding wheel 11. The table 21 is moved in an X-axis direction (a left-right direction in fig. 1) parallel to the upper surface of the base 2 and serving as an axial direction of the workpiece W by an X-axis feeding device 60 including an X-axis motor 61 and an X-axis ball screw (not shown).

The headstock 22 and the tailstock 23 are disposed on the upper surface of the table 21 so as to face each other and support one end or the other end of the workpiece W. A spindle 27 rotated by a spindle rotation driving device 26 is attached to the headstock 22, and the workpiece W is rotated by the rotation driving of the spindle 27. The spindle rotation driving device 26 controls the rotation speed, rotation phase, and the like of the spindle 27 by the control device 40. The main spindle 27 is provided with a chuck 24 for gripping one end of the workpiece W, and the tailstock 23 is provided with a center 25 for supporting the other end of the workpiece W. Therefore, the workpiece W is supported at both ends by the chuck 24 and the center 25 so as to be rotatable about an axis parallel to the moving direction (X-axis direction) of the table 21, and is rotationally driven by the spindle rotation driving device 26.

The dresser 30 is a known diamond dresser, and is a dresser holding portion 22a fixedly held on the side surface of the spindle stock 22 on the wheel head 10 side, and dresses the grinding surface 112a of the outer periphery of the grinding wheel 11. The dresser 30 includes a columnar shank 31 and a diamond whetstone 32 fixed to a tip of the shank 31.

The control device 40 corresponds to a control unit of the present invention, and is a CNC control device configured by using a computer having a CPU, a ROM, a RAM, a hard disk, and the like, and performing numerical control by executing a machining program to perform grinding of the workpiece W and dressing of the grinding wheel 11. The control device 40 is connected to the X-axis feed device 60, the Z-axis feed device 50, the wheel rotation drive device 15 for rotationally driving the wheel spindle 12, and the spindle rotation drive device 26 for rotationally driving the spindle 27, and is connected to various sensors, and processes signals from the sensors to control the respective parts. The control device 40 further includes an input means for inputting a machining program and the like, and an output means for outputting processing contents, processing statuses, and the like (both not shown).

(2. dressing method of grinding wheel)

Next, a dressing method of the grinding wheel according to the present embodiment will be described with reference to fig. 2. Fig. 2 is a flowchart showing a flow of a dressing method of a grinding wheel. As shown in fig. 2, the dressing method of the grinding wheel according to the present embodiment includes a wear amount measuring step S1(S indicates a step, and the other steps are the same), a feed speed calculating step S2, and a dressing step S3.

The wear amount measuring step S1 is a step of measuring the wear amount of the diamond segments 32 generated when the dresser 30 dresses the grinding wheel 11 once in the wheel width direction. Specifically, as shown in fig. 3, the wear amount measuring step S1 includes a preliminary dressing step S11, a reference surface machining step S12, a grinding wheel shape transfer step S13, and a straightness measuring step S14.

First, in the preliminary dressing step S11, the grinding wheel 11 is dressed by a conventional method while rotating the grinding wheel 11. That is, in the preliminary dressing step S11, as shown in fig. 4, the dressing tool 30 and the grindstone 11 are relatively moved in the grindstone width direction (X-axis direction) by the X-axis feed device 60 without changing the relative position in the feed direction (Z-axis direction) of the dressing tool 30 and the grindstone 11. Thus, the grinding surface 112a is formed as an inclined surface whose radial height gradually increases from the dressing start-side end toward the dressing end-side end in the grinding wheel width direction. Therefore, as shown on the right side of fig. 4, the grinding surface 112a after dressing has a lower corner (smaller diameter) on the dressing start side (left side) and a higher corner (larger diameter) on the dressing end side (right side).

Next, in the reference surface processing step S12, the workpiece W and the grinding wheel 11 are rotated, respectively, to process a reference surface parallel to the grinding wheel width direction on the workpiece W. That is, as shown in fig. 5, the grinding wheel 11 having finished the preliminary dressing step S11 is moved in the Z-axis direction to a predetermined feed position by the Z-axis feed device 50, and the workpiece W is moved relative to the grinding wheel in the X-axis direction from one end to the other end via the table 21, whereby a reference surface is machined on the outer periphery of the workpiece W.

Next, in the grinding wheel shape transfer step S13, the grinding wheel shape of the grinding wheel 11 is transferred to the reference surface of the workpiece W. Specifically, as shown in fig. 6, the grindstone 11 is opposed to an intermediate position in the axial direction of the workpiece W, and the grindstone is advanced by Δ X in the X-axis direction at this position. Δ X is a value sufficiently larger than the amount of diamond abrasion. As a result of the grinding wheel shape transfer step S13, as shown in fig. 7, the grinding wheel shape is transferred to the reference surface of the workpiece W to form a transfer groove.

Next, in the straightness measuring step S14, the straightness of the transfer groove G formed in the grinding wheel shape transfer step S13 is measured. For measuring the linearity, a known linearity meter or a known roughness meter can be used. Specifically, positioning is performed in order from the reference surface in the X-axis direction of the transfer groove G, the difference between the Z-axis displacement length and the reference surface at each position is measured, and as shown in fig. 7, the maximum difference a in displacement from a straight line L passing through the starting point P of the measured value and parallel to the reference surface is taken as the straightness. In the following process, the value "a" of the straightness is used as the diamond wear amount "a".

After the wear amount measuring step S1, the cutting feed speed of the grinding wheel is calculated in a cutting feed speed calculating step S2. In the dressing step S3 described later, as shown in fig. 8, the grinding wheel 11 is advanced by the diamond wear amount a while the dressing tool 30 is moved in the X-axis direction relative to the grinding wheel 11 by the grinding wheel width d. Therefore, when the X-axis direction movement speed of the dresser 30 is V1, the feed speed V2 of the grinding wheel 11 can be calculated as V2 being V1 × a/d. The X-axis direction movement speed V1 of the dresser 30 is a value predetermined based on the type of the grinding wheel 11. The control device 40 executes the cutting speed calculation step S2, thereby constituting a cutting speed calculation unit according to the present invention.

After the feed speed calculating step S2, the grinding wheel 11 is rotated to execute a dressing step S3. In the dressing step S3, the control device 40 sets the rotational speed of the grindstone 11, the X-axis position information of the dressing start position, the X-axis direction movement speed V1, and the Z-axis direction movement speed (the feed speed of the grindstone 11) V2, and executes dressing. Fig. 8 shows the state at the start of dressing on the left side, the state at the end of dressing on the right side, and the position of the grinding wheel 11 before the start of cutting by a broken line. At the end of dressing, the diamond table 32 is worn shorter than at the start of dressing, but the dressing tool 30 is moved in the X-axis direction at the speed V1 by the X-axis feeding device 60, and the grindstone 11 is fed at the speed V2 by the Z-axis feeding device 50, whereby the grinding surface 112a parallel to the grindstone width direction can be regenerated while eliminating the influence of wear.

Then, by using the grinding wheel 11 having the non-inclined grinding surface 112a dressed by the method of the present embodiment described above, grinding with a reduced feed mark can be performed on the workpiece W.

(3. summary)

As described above, according to the present embodiment, the wear amount of the dresser 30 with respect to the grinding wheel width is measured, the wear amount of the dresser 30 with respect to the grinding wheel width is used as the feed amount, and the grinding wheel 11 and the dresser 30 are relatively moved in the feed direction in accordance with the relative movement of the grinding wheel 11 and the dresser 30 in the grinding wheel width direction, whereby the effect of wear accompanying dressing of the dresser 30 is eliminated, and the grinding surface 112a parallel to the grinding wheel width direction can be regenerated.

In addition, in the present embodiment, there is provided a feed speed calculation step S2 of calculating a feed speed V2 as a relative movement speed in the feed direction based on the diamond wear amount a and a width direction speed V1 as a relative movement speed in the grinding wheel width direction determined in advance, and in the dressing step S3, the grinding wheel 11 and the dressing tool 30 are relatively moved in the grinding wheel width direction at the width direction speed V1 by the X-axis feeding device 60, and the grinding wheel 11 and the dressing tool 30 are relatively moved in the feed direction at the feed speed V2 by the Z-axis feeding device 50. Therefore, the grinding surface 112a parallel to the grinding wheel width direction can be regenerated by inputting the width direction speed V1 and the feed speed V2 to the control device 40, moving the table 21 in the X axis direction at the width direction speed V1, and moving the wheel head 10 toward the dresser 30 side in the Z axis direction at the feed speed V2.

In the present embodiment, the wear amount measuring step S1 includes a preliminary dressing step S11 of dressing the grindstone 11 without relatively moving the grindstone 11 and the dressing tool 30 in the cutting direction (Z-axis direction), a reference surface machining step S12 of machining a reference surface parallel to the grindstone width direction on the workpiece W, a grindstone shape transfer step S13 of transferring the grindstone shape of the grindstone 11 to the reference surface of the workpiece W to form a transfer groove, and a straightness measuring step S14 of measuring the straightness of the transfer groove formed in the grindstone shape transfer step S13, and the straightness obtained in the straightness measuring step S14 is set as the diamond wear amount. Therefore, by measuring the straightness of the transfer groove using a straightness meter and a roughness meter, the diamond wear amount can be accurately measured. The dressing tool 30 is a diamond single stone dressing tool in which the diamond single stone 32 is fixedly held at the tip end, and according to the method of the present embodiment, the wear amount of the diamond single stone 32 continuously worn by dressing can be measured as the dressing tool wear amount.

(4. modification)

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. In the above embodiment, the example of measuring the straightness of the transfer groove to which the grindstone shape is transferred to the workpiece W in order to measure the diamond wear amount is shown, but the present invention is not limited to this.

For example, in the wear amount measuring step S1, after the preliminary dressing step S11 of dressing the grindstone 11 without relatively moving the grindstone 11 and the dressing tool 30 in the cutting direction, a height measuring step of measuring the radial height at each of the two ends in the grinding wheel width direction of the grinding surface 112a of the grindstone 11 may be performed instead of the steps S12 to S14, and the difference between the radial heights at the two ends in the grinding wheel width direction obtained in the height measuring step may be used as the diamond wear amount. In the height measuring step, for example, the touch sensor may be brought into contact with a plurality of positions on the grinding surface 112a, the mechanical coordinates at the time of the respective contacts may be acquired from the control device 40, and the maximum value of the difference between the respective mechanical coordinates may be set as the diamond wear amount.

Further, although the diamond single stone dresser 30 is shown as an example of the dresser 30, the present invention can be applied to a case where a roller type dresser made by sintering granular diamond or CBN around the entire periphery of a disk shape is used when the dresser is worn, as in the above-described embodiment.