CN110769979A

CN110769979A - Grinding wheel and grinding machine

Info

Publication number: CN110769979A
Application number: CN201780090848.XA
Authority: CN
Inventors: 市原浩一
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 2016-05-17
Filing date: 2017-11-17
Publication date: 2020-02-07
Anticipated expiration: 2037-11-17
Also published as: KR102486869B1; JPWO2018211722A1; WO2018211722A1; TW201741074A; JP7009464B2; JP2018027574A; TWI632027B; KR20200004885A; CN110769979B

Abstract

The invention provides a grinding wheel and a grinding machine which can restrain generation of vibration lines and the like on the surface of a material to be cut during grinding. Therefore, a grinding wheel for a grinding machine includes: a plurality of 1 st spiral grooves provided on an outer peripheral surface of the grinding wheel; and a plurality of 2 nd spiral grooves provided on the outer peripheral surface and intersecting with the plurality of 1 st spiral grooves, respectively. The grinding machine is provided with the grinding wheel. The grinding machine may further include a movable table having a sliding surface that slides on the fixed surface, and the sliding surface may have a plurality of minute recesses that are formed continuously and periodically in the moving direction of the movable table.

Description

Grinding wheel and grinding machine

Technical Field

The present invention relates to a grinding wheel or the like for a grinding machine.

Background

Conventionally, grinding wheels used in grinding machines are known (for example, see patent document 1).

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-226634

Disclosure of Invention

Technical problem to be solved by the invention

The grinding wheel may clog with use, resulting in a decrease in grinding performance. Therefore, dressing work (dressing work) for regenerating grinding performance is sometimes performed.

In the dressing operation, for example, a dresser having a single diamond is used to form a cutting groove (dressing groove) smaller than the outer diameter of the abrasive grains (for example, several μm to several tens μm) in the outer peripheral surface of the grinding wheel. Specifically, the dresser is brought into contact with the rotating grinding wheel and reciprocated in the width direction of the grinding wheel. According to the dressing operation, one spiral dressing groove is formed in the outer peripheral surface of the grinding wheel by the outward movement of the dresser in the width direction, and another spiral dressing groove intersecting the one dressing groove is formed by the return movement. That is, a pyramid having a substantially rhombic bottom surface, that is, a substantially quadrangular pyramid-shaped peak (hereinafter, referred to as a "trimmed peak") is formed by the intersecting one and the other trimmed grooves.

However, in the grinding wheel regenerated by this dressing work, dressing peaks formed by the intersection of one dressing groove with the other dressing groove are formed only at two angular positions in the circumferential direction (i.e., the rotational direction) that are 180 ° symmetric. Therefore, when grinding is performed using the grinding wheel, the workpiece is ground near the apex of the dressing peak, and therefore, the range not cut by the dressing peak becomes larger with the rotation of the grinding wheel than the portion periodically cut by the dressing peak, and a ripple (chatter mark) may be generated on the surface of the workpiece.

In view of the above, it is an object of the present invention to provide a grinding wheel and a grinding machine capable of suppressing generation of chatter marks and the like on the surface of a workpiece during grinding.

Means for solving the technical problem

In order to achieve the above object, one embodiment provides a grinding wheel for use in a grinding machine, the grinding wheel including: a plurality of 1 st spiral grooves provided on an outer peripheral surface of the grinding wheel; and a plurality of 2 nd spiral grooves provided on the outer peripheral surface and intersecting with the plurality of 1 st spiral grooves, respectively.

Another embodiment of the present invention provides a grinding machine including the grinding wheel.

Effects of the invention

According to the above embodiment, it is possible to provide a grinding wheel and a grinding machine capable of suppressing generation of chatter marks and the like on the surface of a workpiece during grinding.

Drawings

Fig. 1 is a view schematically showing an example of the structure of a surface grinding machine according to the present embodiment.

Fig. 2 is a diagram showing a 1 st example of the configuration of the dressing apparatus according to the present embodiment.

Fig. 3A is a diagram for explaining a 1 st example of the trimming method according to the present embodiment.

Fig. 3B is a diagram for explaining example 1 of the trimming method according to the present embodiment.

Fig. 3C is a diagram for explaining example 1 of the trimming method according to the present embodiment.

Fig. 4A is a diagram showing an example of a grinding wheel after a dressing operation is performed using the dressing apparatus according to the comparative example.

Fig. 4B is a diagram showing an example of a grinding wheel after a dressing operation is performed using the dressing apparatus according to the present embodiment.

Fig. 5 is a view schematically showing an example 2 of the configuration of the dressing apparatus according to the present embodiment.

Fig. 6 is a diagram for specifically explaining the arrangement of the finisher.

Fig. 7A is a diagram for explaining example 2 of the trimming method according to the present embodiment.

Fig. 7B is a diagram for explaining example 2 of the trimming method according to the present embodiment.

Fig. 7C is a diagram for explaining example 2 of the trimming method according to the present embodiment.

Fig. 8A is a diagram for explaining example 2 of the trimming method according to the present embodiment.

Fig. 8B is a diagram for explaining example 2 of the trimming method according to the present embodiment.

Fig. 8C is a diagram for explaining example 2 of the trimming method according to the present embodiment.

Fig. 9 is a view schematically showing example 3 of the configuration of the dressing apparatus according to the present embodiment.

Fig. 10A is a diagram for specifically explaining the arrangement of the finisher.

Fig. 10B is a diagram for specifically explaining the arrangement of the finisher.

Fig. 11A is a diagram for explaining example 3 of the trimming method according to the present embodiment.

Fig. 11B is a diagram for explaining example 3 of the trimming method according to the present embodiment.

Fig. 11C is a diagram for explaining example 3 of the trimming method according to the present embodiment.

Fig. 12 is a diagram schematically showing example 4 of the configuration of the dressing apparatus according to the present embodiment.

Fig. 13A is a diagram for explaining example 4 of the trimming method according to the present embodiment.

Fig. 13B is a diagram for explaining example 4 of the trimming method according to the present embodiment.

Fig. 14A is a diagram for explaining example 5 of the trimming method according to the present embodiment.

Fig. 14B is a diagram for explaining example 5 of the trimming method according to the present embodiment.

Fig. 14C is a diagram for explaining example 5 of the trimming method according to the present embodiment.

Fig. 15 is a diagram for explaining a method of machining a grinding wheel after a dressing operation is performed using the dressing apparatus according to the present embodiment.

Fig. 16 is a view showing an example of a sliding surface to which a plurality of dimples formed by the machining method shown in fig. 15 can be applied.

Fig. 17 is a diagram schematically showing an example of the structure of the cylindrical grinding machine according to the present embodiment.

Fig. 18 is a diagram schematically showing another example of the structure of the cylindrical grinding machine according to the present embodiment.

Fig. 19 is a diagram schematically showing an example of the structure of the internal grinding machine according to the present embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[ Structure of surface grinder ]

First, an example of a grinding machine (i.e., a surface grinding machine) according to the present embodiment will be described with reference to fig. 1.

Fig. 1 is a view schematically showing an example of the structure of a surface grinding machine 1 according to the present embodiment.

The surface grinding machine 1 includes a movable table 10, a table guide mechanism 11, a grinding wheel head 15, a grinding wheel 16, a guide rail 18, a control device 20, and a display device 40.

In fig. 1, the X direction indicates the moving direction of the movable table 10, the Y direction indicates the moving direction of the wheel head 15 orthogonal to the X direction, and the Z direction indicates the height direction orthogonal to the X direction and the Y direction.

The movable table 10 is provided so as to be movable in the X direction by a table guide mechanism 11, and a workpiece 12 to be ground is placed thereon.

The table guide mechanism 11 moves the movable table 10 in the X direction using, for example, a servo motor or the like as a driving force source.

The grinding wheel head 15 is provided with a grinding wheel 16 at its lower end portion, and is attached to a guide rail 18 so as to be movable in the Y direction and movable up and down in the Z direction.

The grinding wheel 16 has a cylindrical shape, and is rotatably attached to the lower end portion of the grinding wheel head 15 with its central axis parallel to the Y direction. The grinding wheel 16 moves in the Y direction and the Z direction together with the grinding head 15, and rotates to grind the surface of the workpiece 12. The grinding wheel 16 is mainly composed of abrasive grains (for example, alumina abrasive or diamond abrasive) selected according to the properties of the material 12 to be cut, the machining accuracy, and the like, and a binder holding the abrasive grains.

The guide rail 18 moves the wheel head 15 in the Y direction and the Z direction using, for example, two servomotors or the like as a driving force source.

The controller 20 controls each part of the surface grinding machine 1 to adjust the positions of the movable table 10 and the grinding wheel head 15 and rotate the grinding wheel 16 to grind the surface of the workpiece 12. The control device 20 is mainly constituted by a computer including, for example, a CPU, a RAM, a ROM, an I/O, and the like.

The display device 40 is, for example, a liquid crystal display or the like. The display device 40 is controlled by the control device 20, and displays, for example, a grinding condition of the material 12 to be cut and the like.

[ 1 st example of dressing device ]

Next, referring to fig. 2, a dressing apparatus 100 that performs a dressing operation (dressing operation) of the grinding wheel 16 used in the surface grinding machine 1 will be described.

Fig. 2 is a view schematically showing example 1 of the configuration of the finisher 100 according to the present embodiment.

The dressing apparatus 100 includes a dresser 110, a driving mechanism 120, a rotating mechanism 130, a rotational position detecting device 140, and a controller 150.

The dresser 110 is in contact with an outer peripheral surface of the rotating grinding wheel 16 (i.e., a work surface for grinding a workpiece, hereinafter, may be referred to as a "grinding wheel work surface") to form a cutting groove (dressing groove). The dresser 110 is, for example, made of single diamond, has a substantially cylindrical shape and a conical shape at its tip. The dresser 110 can form a dressing groove having a smaller width (for example, several μm to several tens μm) than the abrasive grains.

The driving mechanism 120 moves the dresser 110 (specifically, a holding member that holds the dresser 110) in the left-right direction (positive direction and negative direction of the X axis in the drawing) and the up-down direction (positive direction and negative direction of the Z axis in the drawing) using, for example, two servomotors as driving force sources. The drive mechanism 120 includes, for example, a ball screw mechanism or a rack and pinion mechanism. The driving mechanism 120 adjusts the position in the left-right direction and the position in the up-down direction according to a control command from the controller 150. This makes it possible to control the contact state (depth of the dressing groove) between the dresser 110 and the outer peripheral surface (grinding wheel face) of the grinding wheel 16 attached to the rotary shaft 131 described later and the contact position in the width direction (left-right direction in the drawing) of the grinding wheel 16.

The rotation mechanism 130 rotates the grinding wheel 16 attached to the rotary shaft 131 at a predetermined rotation speed using, for example, a servo motor or the like as a driving force source.

The rotational position detecting device 140 is, for example, a rotary encoder that detects the rotational position (angular position) of the grinding wheel 16 attached to the rotating shaft 131. The rotational position detecting device 140 is communicatively connected to the controller 150, and a detection signal corresponding to the angular position of the grinding wheel 16 detected by the rotational position detecting device is transmitted to the controller 150.

The controller 150 sends a control command to the driving mechanism 120, and controls the position in the left-right direction and the position in the up-down direction of the dresser 110 that is driven by the driving mechanism 120 to move in the up-down left-right direction. The controller 150 is mainly constituted by a computer including, for example, a CPU, a RAM, a ROM, an I/O, and the like. The controller 150 can control the contact state (depth of the dressing groove) of the dresser 110 with the outer peripheral surface (grinding wheel face) of the grinding wheel 16 by adjusting the position of the driving mechanism 120 in the vertical direction. Further, the controller 150 controls the position in the left-right direction of the dresser 110 (the contact position in the width direction of the grinding wheel 16) and synchronizes with the angular position of the grinding wheel 16 based on the detection signal received from the rotational position detecting device 140.

[ 1 st example of dressing method ]

Next, a dressing method (example 1 of the dressing method according to the present embodiment) performed using the dressing apparatus 100 shown in fig. 2 will be described with reference to fig. 3A to 3C.

Fig. 3A to 3C are diagrams for explaining example 1 of the trimming method according to the present embodiment. Specifically, fig. 3A to 3C show the operation of the finisher 100 shown in fig. 2.

As described later, the finisher 100 repeats the following three times: the dresser 110 is brought into contact with the rotating grinding wheel 16 and reciprocated between the left and right ends of the grinding wheel 16 attached to the rotating shaft 131. Fig. 3A to 3C are developed views of the outer peripheral surface (grinding wheel face) of the grinding wheel 16 showing the state of the dressing groove formed in the 1 st to 3 rd steps, respectively.

In fig. 3B and 3C, the trimming grooves formed in the previous step are indicated by broken lines, and the trimming

grooves

202 and 212 and the trimming

grooves

203 and 213 formed in the 2 nd and 3 rd steps are indicated by solid lines. The 1 st step to the 3 rd step are performed in the following order: first, the dresser 110 is moved from the left end to the right end of the grinding wheel 16, and then, the dresser is moved from the right end to the left end. In this example, the moving speed of the dresser 110 in the left-right direction, specifically, the amount by which the dresser 110 moves left and right (hereinafter referred to as "dressing feed amount") DL each time the grindstone 16 rotates one revolution is 1/2 of the width W of the grindstone 16 (that is, the dressing feed amount DL is W/2). The angular position (0 ° to 360 °) of the grinding wheel 16 is predetermined, and the rotational position detector 140 transmits a detection signal corresponding to the angular position to the controller 150. In the figure, the left end position of the grinding wheel 16 is indicated by a coordinate value "0", and the right end position of the grinding wheel 16 is indicated by a coordinate value "W".

In the 1 st step, first, the controller 150 controls the driving mechanism 120 so that the dresser 110 starts to contact the left end position (index value "0") of the grinding wheel 16 at the angular position "0 °" and moves by the dressing feed amount DL (═ W/2) in the right direction. Next, when the dresser 110 reaches the right end position (coordinate "W") of the grinding wheel 16, the controller 150 controls the driving mechanism 120 so that the dresser 110 moves in the reverse direction, that is, in the leftward direction by the dressing feed amount DL (═ W/2). Specifically, the controller 150 controls the driving mechanism 120 so that the dresser 110 starts to come into contact with the right end position (coordinate value "W") of the grinding wheel 16 at the angular position "0 °" and moves in the left direction by the dressing feed amount DL (═ W/2). Further, the controller 150 controls the driving mechanism 120 to move the dresser 110 to the left end position of the grinding wheel 16 (coordinate value "0").

As shown in fig. 3A, the dresser 110 moves in the outward path of the 1 st step in the rightward direction (upward direction in fig. 3A) by the dressing feed amount DL (═ W/2), thereby forming a spiral dressing groove 201 (in the drawing, see white arrows) on the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °" at the left end of the grinding wheel 16 and ending at the angular position "360 °" (- ("0 °") at the right end of the grinding wheel 16. The dressing groove 201 is spirally wound two times along the outer peripheral surface of the grinding wheel 16.

Further, as shown in fig. 3A, the dresser 110 moves in the left direction (downward direction in fig. 3A) by the dressing feed amount DL (═ W/2) in the circuit of the 1 st step, and therefore, a spiral dressing groove 211 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °" at the right end of the grinding wheel 16 and ending at the angular position "360 °" (- "0 °") at the left end of the grinding wheel 16 (in the figure, refer to black arrows). The dressing groove 211 is spirally wound two times along the outer peripheral surface of the grinding wheel 16. And, the trimming groove 211 intersects with the trimming groove 201.

In the 2 nd step, the controller 150 moves the dresser 110 with a phase (angular position of the grinding wheel 16) shifted from that in the 1 st step. Specifically, the controller 150 controls the driving mechanism 120 so that the dresser 110 starts to contact the left end position (coordinate value "0") of the grinding wheel 16 at the angular position "120 °" and moves by the dressing feed amount DL (═ W/2) in the right direction. Next, when the dresser 110 reaches the right end position (coordinate "W") of the grinding wheel 16, the controller 150 controls the driving mechanism 120 so that the dresser 110 moves in the reverse direction, that is, in the leftward direction by the dressing feed amount DL (═ W/2). Specifically, the controller 150 controls the driving mechanism 120 so that the dresser 110 starts to come into contact with the right end position (coordinate value "W") of the grinding wheel 16 at the angular position "120 °" and moves in the leftward direction by the dressing feed amount DL (═ W/2). Further, the controller 150 controls the driving mechanism 120 to move the dresser 110 to the left end position of the grinding wheel 16 (coordinate value "0").

As shown in fig. 3B, the dresser 110 moves in the outward path of the 2 nd step in the rightward direction (upward direction in fig. 3B) by the dressing feed amount DL (W/2), thereby forming a spiral dressing groove 202 in the outer peripheral surface of the grinding wheel 16, the spiral dressing groove having a starting point of the angular position "120 ° at the left end of the grinding wheel 16 and an ending point of the angular position" 120 ° at the right end of the grinding wheel 16 (see white arrows in the drawing). The dressing groove 202 is spirally wound two times along the outer peripheral surface of the grinding wheel 16 in parallel with the dressing groove 201 (i.e., not intersecting the dressing groove 201). On the other hand, the trimming groove 202 intersects with the trimming groove 211 formed in the 1 st step.

As shown in fig. 3B, the dresser 110 moves in the loop of the 2 nd step in the left direction (downward direction in fig. 3B) by the dressing feed amount DL (W/2), thereby forming a spiral dressing groove 212 on the outer peripheral surface of the grinding wheel 16, the spiral dressing groove having the angular position "120 °" at the right end of the grinding wheel 16 as a starting point and the angular position "120 °" at the left end of the grinding wheel 16 as an end point (in the figure, refer to black arrows). The dressing groove 212 is spirally wound two times along the outer peripheral surface of the grinding wheel 16 in parallel with the dressing groove 211 (i.e., not intersecting the dressing groove 211). On the other hand, the trimming groove 212 intersects with the trimming groove 201 formed in the 1 st step and the trimming groove 202 formed in the 2 nd step (outward route).

In the 3 rd step, the controller 150 moves the dresser 110 with a further phase shift (angular position of the grinding wheel 16) from the 2 nd step. Specifically, the controller 150 controls the driving mechanism 120 so that the dresser 110 starts to contact the left end position (coordinate value "0") of the grinding wheel 16 at the angular position "240 °" and moves by the dresser feed amount DL (═ W/2) in the right direction. Next, when the dresser 110 reaches the right end position (coordinate "W") of the grinding wheel 16, the controller 150 controls the driving mechanism 120 so that the dresser 110 moves in the reverse direction, that is, in the leftward direction by the dressing feed amount DL (═ W/2). Specifically, the controller 150 controls the driving mechanism 120 so that the dresser 110 starts to come into contact with the right end position (coordinate value "W") of the grinding wheel 16 at the angular position "240 °" and moves in the leftward direction by the dressing feed amount DL (═ W/2). Further, the controller 150 controls the driving mechanism 120 to move the dresser 110 to the left end position of the grinding wheel 16 (coordinate value "0").

As shown in fig. 3C, the dresser 110 moves in the outward path of the 3 rd step in the rightward direction (upward direction in fig. 3C) by the dressing feed amount DL (W/2), thereby forming a spiral dressing groove 203 on the outer peripheral surface of the grinding wheel 16, the spiral dressing groove starting at an angular position "240 °" at the left end of the grinding wheel 16 and ending at an angular position "240 °" at the right end of the grinding wheel 16 (see white arrows in the drawing). The dressing groove 203 is spirally wound two times along the outer peripheral surface of the grinding wheel 16 in parallel with the dressing grooves 201, 202 (i.e., not intersecting the dressing grooves 201, 202). On the other hand, the trimming groove 203 intersects with the trimming groove 211 formed in the 1 st step and the trimming groove 212 formed in the 2 nd step.

As shown in fig. 3C, the dresser 110 moves in the loop of the 3 rd step in the left direction (downward direction in fig. 3C) by the dressing feed amount DL (W/2), thereby forming a spiral dressing groove 213 in the outer peripheral surface of the grinding wheel 16, the spiral dressing groove having an angular position "240 °" at the right end of the grinding wheel 16 as a starting point and an angular position "240 °" at the left end of the grinding wheel 16 as an end point (in the figure, refer to black arrows). The dressing groove 213 is spirally wound two times along the outer peripheral surface of the grinding wheel 16 in parallel with the dressing grooves 211, 212 (i.e., not intersecting the dressing grooves 211, 212). On the other hand, the trimming grooves 213 intersect the trimming grooves 201 to 203 formed in the 1 st to 3 rd steps.

As shown in fig. 3C, the dressing grooves 201 to 203 formed in the outward paths in the 1 st step to the 3 rd step are formed spirally on the outer peripheral surface of the grinding wheel 16, and are arranged in parallel with each other at equal intervals (i.e., at the same pitch DP (═ DL/3)). That is, three dressing grooves 201 to 203 are formed on the outer peripheral surface (grinding wheel face) of the grinding wheel 16. The dressing grooves 211 to 213 formed in the respective circuits in the 1 st to 3 rd steps are formed spirally on the outer peripheral surface of the grinding wheel 16, and are arranged in parallel with each other at equal intervals (i.e., at the same pitch DP (DL/3)). That is, three dressing grooves 211 to 213 intersecting the dressing grooves 201 to 203 are formed on the outer peripheral surface (grinding wheel face) of the grinding wheel 16.

As described above, the trimming grooves 201 to 203 intersect the trimming grooves 211 to 213. Therefore, as shown in fig. 3C, a cone having a substantially diamond-shaped region surrounded by two of the trimming grooves 201 to 203 and two of the trimming grooves 211 to 213 as a bottom surface (i.e., a substantially quadrangular pyramid-shaped peak (trimming peak)) is formed. The dressing peak corresponds to a portion for grinding the cut material 12 with the surface grinding machine 1.

In the present embodiment, the number Z of the pairs of the plurality of trimming grooves (the trimming grooves 201 to 203 and the trimming grooves 211 to 213) is 3, but the number Z may be 2 or 4 or more. In this case, the phase shift amount may be changed according to the number Z. In the present embodiment, the number of the dresser 110 is three times by changing the phase of "120 °" for each 3 pieces, but for example, in the case of 2 pieces, the phase of "180 °" may be changed by twice by making the dresser 110 reciprocate. For example, in the case where the number of the trimmer 110 is 4, the phase of "90 °" may be changed every time the trimmer 110 is reciprocated four times. That is, the phase may be changed by (360/Z) ° "every time depending on the number Z, and the dresser 110 may be reciprocated Z times to form a plurality of dressing grooves in pairs.

[ Effect ]

Next, referring to fig. 4A and 4B, the operation of the grinding wheel 16 (i.e., the grinding wheel 16 formed with the dressing grooves 201 to 203 and the dressing grooves 211 to 213 shown in fig. 3C) after the dressing operation using the dressing apparatus 100 shown in fig. 2 will be described.

Fig. 4A is a diagram showing an example of the grinding wheel 16 after the dressing operation is performed using the dressing apparatus according to the comparative example, and fig. 4B is a diagram showing an example of the grinding wheel 16 after the dressing operation is performed using the dressing apparatus 100 according to the present embodiment. Specifically, fig. 4A and 4B are developed views of the outer peripheral surface (grinding wheel face) of the grinding wheel 16.

Further, the trimming apparatus according to the comparative example corresponding to the related art performs only the 1 st step in the trimming apparatus 100 according to the present embodiment. In order to equalize the intervals (pitches) between the dressing grooves at the same angular positions on the outer peripheral surface of the grinding wheel 16, the dressing feed amount DLc in the dressing device according to the comparative example was W/6(DLc is W/6). The black circles in the figure schematically indicate the apexes of the trimming peaks.

As shown in fig. 4A, 1

spiral dressing groove

201c and 1 spiral dressing groove 211c intersecting the dressing groove 201c are formed in the outer peripheral surface (grinding wheel face) of the grinding wheel 16 after the dressing operation using the dressing apparatus according to the comparative example. In the comparative example, since the dressing feed amount DLc is W/6 as described above, the dressing

grooves

201c and 211c are wound spirally for 6 turns along the outer peripheral surface of the grinding wheel 16. The diamond-shaped dressing peaks surrounded by the mutually intersecting dressing

grooves

201c, 211c are formed so as to be aligned in the width direction at two angular positions (specifically, at an angular position "180 °" and an angular position "360 °" (- "0 °") of the grinding wheel 16 that are symmetrical at 180 °. In other words, two dressing peaks are arranged in the direction of the dressing groove 201c or the dressing groove 211c at 1 circumference of the outer peripheral surface (grinding wheel face) of the grinding wheel 16.

In this way, the grinding wheel 16 after the dressing operation using the dressing apparatus according to the comparative example has the dressing peaks formed only at two angular positions on the outer peripheral surface (grinding wheel working surface) that are symmetrical at 180 °. Therefore, when the grinding wheel 16 attached to the surface grinding machine 1 grinds the workpiece 12 while rotating, there is a possibility that portions of the workpiece 12 ground by portions other than the vicinities of the two angular positions where the dressing peaks are formed are hardly ground. As a result, the difference between the portion ground by the dressing peak and the portion not ground at all in the workpiece 12 becomes significant, and there is a possibility that waviness or chatter marks (chatter marks) may occur on the surface of the workpiece 12. That is, the quality of the workpiece 12 may be degraded.

On the other hand, as shown in fig. 4B, the grinding wheel 16 after the dressing operation using the dressing apparatus 100 according to the present embodiment has three dressing grooves 201 to 203 and three dressing grooves 211 to 213 intersecting with the three dressing grooves 201 to 203, respectively, as described above. Then, by the intersections of the three trimming grooves 201 to 203 and the three trimming grooves 211 to 213, trimming peaks are formed at six angular positions (angular positions "60 °", "120 °", "180 °", "240 °", "300 °" and "360 °" ("0 °")) in such a manner as to be aligned in the width direction. In other words, six (2 · Z) dressing peaks are arranged in the direction of the dressing grooves 201 to 203 or the dressing grooves 211 to 213 at 1 circumference of the outer peripheral surface (the grinding wheel working surface) of the grinding wheel 16.

Therefore, since the grinding wheel 16 attached to the surface grinding machine 1 grinds the workpiece 12 by the truing peaks formed at six angular positions of the outer peripheral surface (grinding wheel face) while rotating, it is possible to suppress the occurrence of waviness, chatter marks, and the like on the surface of the workpiece 12 as compared with the case of the comparative example. Further, by setting the number Z of the formed pair of the plurality of dressing grooves to be larger (Z ≧ 4), the number of angular positions (2 · Z) of the grinding wheel 16 at which the dressing peak is arranged increases, and thus generation of waviness, chattering, and the like on the surface of the work material 12 can be further suppressed.

The dressing feed amount DL of the pair of dressing grooves (i.e., the amount of movement of the dressing grooves 201 to 203, 211 to 213 in the width direction per 1 rotation of the outer peripheral surface of the grindstone 16) is more preferably 0.1mm or more. The pitch DP of the plurality of dressing grooves in the pair (i.e., the interval between two adjacent dressing grooves among the dressing grooves 201 to 203 in the width direction of the grinding wheel 16 and the interval between two adjacent dressing grooves among the dressing grooves 211 to 213 in the width direction of the grinding wheel 16) is more preferably 0.5mm or less. However, the pitch DP of the paired plural trimming grooves is smaller than the trimming feed amount DL.

[ 2 nd example of dressing device ]

Next, referring to fig. 5, a 2 nd example of the finisher 100 according to the present embodiment will be described.

Fig. 5 is a view schematically showing an example 2 of the configuration of the finisher 100 according to the present embodiment.

The dressing apparatus 100 according to the present example is different from the dressing apparatus of example 1 shown in fig. 2 in that a plurality of (three) dressers 111 to 113 are provided instead of the dresser 110.

Hereinafter, the same components as those of the trimming device 100 shown in fig. 2 are denoted by the same reference numerals, and different portions will be described with emphasis on the description.

The trimmers 111 to 113 are integrally moved in the left-right direction (positive and negative directions of the X axis in the drawing) and the up-down direction (positive and negative directions of the Z axis in the drawing) by the driving of the driving mechanism 120. Hereinafter, a specific arrangement of the trimmers 111 to 113 will be described with reference to fig. 6.

FIG. 6 is a diagram for specifically explaining the arrangement of the finishers 111 to 113.

As shown in FIG. 6, the trimmers 111-113 are arranged in a left-right direction.

The dresser 112 is disposed at a position shifted leftward by a distance L1 with reference to a position of the dresser 111 in the left-right direction (specifically, a position of a tip of the dresser 111 forming the dressing groove in the left-right direction). The distance L1 is the sum of an integral multiple (n times) of the dressing feed amount DL and a value obtained by dividing the dressing feed amount DL by the number Z (3) (L1 is n · DL + DL/Z (n is an integer of 1 or more)). Thus, when the dresser 111 to 113 are integrally moved in the left-right direction by the dressing feed amount DL, the dressing groove formed by the dresser 112 is shifted by DL/3 in the width direction of the grinding wheel 16 with respect to the dressing groove formed by the dresser 111.

The dresser 113 is disposed at a position shifted leftward by a distance L2 with reference to the position of the dresser 111 in the left-right direction. The distance L2 is the sum of an integer multiple (m times) of the trim feed amount DL and a value obtained by dividing the integer multiple of the trim feed amount DL by the number Z (═ 3) (L2 ═ m · DL +2DL/Z (m is an integer greater than n)). Thus, when the dresser 111 to 113 are integrally moved in the left-right direction by the dressing feed amount DL, the dressing groove formed by the dresser 113 is shifted by 2DL/3 in the width direction of the grinding wheel 16 with respect to the dressing groove formed by the dresser 111.

Further, since it is necessary to cut a plurality of dressing grooves into the abrasive grains of the grinding wheel 16, the intervals (pitches) between the dressing grooves are usually set to be sufficiently smaller than the outer dimensions of the dressers 111 to 113. Therefore, as shown by the dotted line in fig. 6, the trimmers 111-113 cannot be easily arranged so as to be shifted by DL/3 in the left-right direction.

[ 2 nd example of dressing method ]

Next, a dressing method (example 2 of the dressing method according to the present embodiment) performed using the dressing apparatus 100 shown in fig. 5 will be described with reference to fig. 7A to 7C and fig. 8A to 8C.

Fig. 7A to 7C and fig. 8A to 8C are diagrams for explaining example 2 of the trimming method according to the present embodiment. Specifically, fig. 7A to 7C and 8A to 8C show the operation of the dressing apparatus 100 shown in fig. 5.

The dressing apparatus 100 according to the present example performs the following process once: the (at least 1) dresser 111 to 113 is brought into contact with the rotating grinding wheel 16 and integrally reciprocated between the left and right ends of the grinding wheel 16 attached to the rotating shaft 131 (hereinafter referred to as "reciprocating step"). Fig. 7A to 7C and fig. 8A to 8C are developed views of the outer peripheral surface (grinding wheel face) of the grinding wheel 16 showing the state of the dressing groove formed in the outward path and the return path in the reciprocating step.

In fig. 7B and 7C, the trimming grooves formed by using another dresser are indicated by broken lines, and the trimming

grooves

202 and 203 formed by using the

dressers

112 and 113 are indicated by solid lines. In fig. 8B and 8C, the trimming grooves formed by using another dresser are indicated by broken lines, and the trimming

grooves

212 and 213 formed by using the

dressers

112 and 111 are indicated by solid lines. The reciprocating process in this example is performed in the following order: the dressers 111 to 113 are integrally moved from the left end to the right end of the grinding wheel 16, and then the dressers 111 to 113 are integrally moved from the right end to the left end of the grinding wheel 16. In this example, the dressing feed amount DL is 1/2 of the width W of the grindstone 16 (that is, the dressing feed amount DL is W/2) as in the example of fig. 3A to 3C. In this example, n.gtoreq.2 and m.gtoreq.4 are assumed.

In the outward path in the reciprocating process, the controller 150 controls the driving mechanism 120 so that the dresser 111 located on the rightmost side among the dressers 111 to 113 starts to contact the left end position (coordinate value "0") of the grinding wheel 16 at the angular position "0 °" and so that the dressers 111 to 113 are integrally moved in the rightward direction by the dressing feed amount DL (═ W/2). Then, the controller 150 controls the driving mechanism 120 to move the leftmost dresser 113 of the dressers 111 to 113 to the right end position (index value "W").

In the outward route, first, as shown in fig. 7A, a trimming groove 201 is formed by the trimmer 111. Specifically, by moving the dresser 111 in the right direction (the upward direction in fig. 7A) by the dressing feed amount DL (═ W/2), a spiral dressing groove 201 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °", at the left end of the grinding wheel 16, and ending at the angular position "360 °" (- "0 °") at the right end of the grinding wheel 16 (in the figure, refer to white arrows).

Next, as shown in fig. 7B, a trimming groove 202 is formed by the trimmer 112. Specifically, by moving the dresser 112 in the right direction (the upward direction in fig. 7B) by the dressing feed amount DL (═ W/2), a spiral dressing groove 202 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "120 °", at the left end of the grinding wheel 16, and ending at the angular position "120 °" (- "0 °") at the right end of the grinding wheel 16 (in the figure, refer to white arrows).

Next, as shown in fig. 7C, a trimming groove 203 is formed by the trimmer 113. Specifically, by moving the dresser 113 in the right direction (upward direction in fig. 7C) by the dressing feed amount DL (═ W/2), a spiral dressing groove 203 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "240 °", at the left end of the grinding wheel 16, and ending at the angular position "240 °" ("0 °") at the right end of the grinding wheel 16 (in the figure, see white arrows).

In the circuit in the reciprocating step, the controller 150 controls the driving mechanism 120 so that the leftmost dresser 113 of the dressers 111 to 113 starts to contact the right end position (index value "W") of the grinding wheel 16 at the angular position "0 °" and the dressers 111 to 113 are integrally moved in the left direction by the dressing feed amount DL (W/2). Then, the controller 150 controls the driving mechanism 120 to move the finisher 111 located on the rightmost side among the finishers 111 to 113 to the left end position (coordinate value "0").

In the circuit, first, as shown in fig. 8A, a trimming groove 211 is formed by the trimmer 113. Specifically, by moving the dresser 113 in the left direction (downward direction in fig. 8A) by the dressing feed amount DL (═ W/2), a spiral dressing groove 211 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °", at the right end of the grinding wheel 16, and ending at the angular position "360 °" (- "0 °") at the left end of the grinding wheel 16 (see black arrows in the figure).

Next, as shown in fig. 8B, a trimming groove 212 is formed by the trimmer 112. Specifically, by moving the dresser 112 in the left direction (downward direction in fig. 8B) by the dressing feed amount DL (W/2), a spiral dressing groove 212 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "120 °" at the right end of the grinding wheel 16 and ending at the angular position "120 °" at the left end of the grinding wheel 16 (see black arrows in the figure).

Next, as shown in fig. 8C, a trimming groove 213 is formed by the trimmer 111. Specifically, by moving the dresser 111 in the left direction (downward direction in fig. 8C) by the dressing feed amount DL (W/2), a spiral dressing groove 213 (see black arrow in the figure) is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "240 °" at the right end of the grinding wheel 16 and ending at the angular position "240 °" at the left end of the grinding wheel 16.

In the present example, the trimming

grooves

211, 212, 213 are formed in the

circuit trimming devices

113, 112, 111 in this order, but the present invention is not limited to this embodiment. For example, the dresser 113 may form the dressing groove 213, the dresser 112 may form the dressing groove 211, and the dresser 111 may form the dressing groove 212. For example, the dresser 113 may form the dressing groove 212, the dresser 112 may form the dressing groove 213, and the dresser 111 may form the dressing groove 211.

In this way, by the dressing method according to the present example (i.e., the dressing apparatus 100 shown in fig. 5), a plurality of dressing grooves (three dressing grooves 201 to 203 and three dressing grooves 211 to 213) can be formed in pairs as in fig. 4B.

Further, according to the dressing method according to the present example (i.e., the dressing apparatus 100 shown in fig. 5), since it is only necessary to reciprocate the plurality of dressers integrally in the left-right direction once, a plurality of dressing grooves in pairs can be formed in a shorter time.

In addition, although the dressing apparatus 100 shown in fig. 5 is provided with three dressers 111 to 113, four or more dressers may be provided to form four or more paired multiple dressing grooves. Further, the trimmers 111-113 may be integrally reciprocated a plurality of times in the left-right direction to form a plurality of trimming grooves in pairs of four or more.

[ 3 rd example of dressing apparatus ]

Next, referring to fig. 9, a description will be given of example 3 of the finisher 100 according to the present embodiment.

Fig. 9 is a diagram schematically showing example 3 of the configuration of the finisher 100 according to the present embodiment.

The dressing apparatus 100 according to the present example is different from example 1 shown in fig. 2 in that a plurality of (three) dressers 111 to 113 are provided instead of the dresser 110, as in example 2 shown in fig. 5.

The dressing apparatus 100 according to the present example is different from the dressing apparatus of example 1 shown in fig. 2 and example 2 shown in fig. 5 in that the dressers 111 to 113 are disposed at different angular positions (positions in the circumferential direction) on the outer peripheral surface of the rotating body 115 having the rotating shaft extending in the left-right direction.

The dressing apparatus 100 according to the present example is different from the dressing apparatus according to example 1 and example 2 shown in fig. 2 in that a rotational position detecting device 125 that detects the rotational position of the rotating body 115 is further provided.

Hereinafter, the same components as those of the trimming device 100 shown in fig. 2 and 5 are denoted by the same reference numerals, and different portions will be described.

The trimmers 111-113 are disposed on the outer peripheral surface of a rotating body 115 having a rotating shaft extending in the left-right direction. Hereinafter, a specific arrangement of the trimmers 111 to 113 will be described with reference to fig. 10A and 10B.

Fig. 10A and 10B are diagrams for specifically explaining the arrangement of the trimmers 111 to 113. Specifically, fig. 10A is a view when the rotor 115 is viewed from the left direction, and fig. 10B is a view when the rotor 115 is viewed from the front.

In fig. 10B, the dresser 113 is located on the back surface of the rotating body 115 and is indicated by a broken line.

As shown in fig. 10A, the trimmers 111 to 113 are arranged at different angular positions (positions in the circumferential direction) on the outer circumferential surface of the rotating body 115.

As shown in fig. 10B, the trimmers 111 to 113 are arranged at intervals of DL/Z (in this example, the number of trimmers Z is 3) in the left-right direction. Specifically, the dresser 112 is disposed at a position shifted by DL/Z in the left direction and the dresser 113 is disposed at a position shifted by 2DL/Z in the left direction with respect to the position of the dresser 111 in the left-right direction.

As will be described later, the rotating body 115 rotates at a sufficiently high rotational speed relative to the rotational speed of the grinding wheel 16. Therefore, as shown by the one-dot chain line in fig. 10B, the grinding wheel 16 rotating at a relatively low speed can be viewed as if the dressers 111 to 113 were arranged in the left-right direction.

Returning to fig. 9, the driving mechanism 120 is provided with another servomotor, for example, and drives the rotating body 115 to rotate. The drive mechanism 120 rotates the rotating body 115 at a sufficiently higher rotation speed than the rotation speed of the grinding wheel 16 by the rotation mechanism 130 (preferably, at least 10 times the rotation speed of the grinding wheel 16 by the rotation mechanism 130). The driving mechanism 120 drives the rotating body 115 provided with the trimmers 111 to 113 to move in the left-right direction (positive direction and negative direction of the X axis in the figure) and in the up-down direction (positive direction and negative direction of the Z axis in the figure).

The rotational position detecting device 125 is, for example, a rotary encoder that detects the rotational position (angular position) of the grinding wheel 16 of the rotating body 115. The rotational position detecting device 125 is communicatively connected to the controller 150, and a detection signal corresponding to the angular position of the rotating body 115 detected by the device is transmitted to the controller 150.

The controller 150 sends a control command to the driving mechanism 120, and controls the position in the left-right direction and the position in the up-down direction of the rotating body 115 including the trimmers 111-113 driven to move in the up-down and left-right directions by the driving mechanism 120. The controller 150 confirms the state in which the rotating body 115 is rotating at a sufficiently high speed relative to the rotation speed of the grinding wheel 16 based on the detection signal from the rotational position detection device 125, and controls the drive mechanism 120.

[ 3 rd example of dressing method ]

Next, a dressing method (example 3 of the dressing method according to the present embodiment) performed using the dressing apparatus 100 shown in fig. 9 will be described with reference to fig. 11A to 11C.

Fig. 11A to 11C are diagrams for explaining example 3 of the trimming method according to the present embodiment. Specifically, fig. 11A to 11C show the operation of the finisher 100 shown in fig. 9.

The dressing apparatus 100 according to the present example performs the following process once: the (at least 1) dresser 111 to 113 is brought into contact with the rotating grinding wheel 16 and integrally reciprocated between the left and right ends of the grinding wheel 16 attached to the rotating shaft 131 (hereinafter referred to as "reciprocating step"). Fig. 11A to 11C are developed views of the outer peripheral surface (grinding wheel face) of the grinding wheel 16 showing the state of the dressing groove formed in the outward path in the reciprocating step.

As shown in fig. 11A, first, the dresser 111 starts forming the dressing groove 201. Thereafter, when the grinding wheel 16 rotates by 120 °, the dresser 112 starts forming a dressing groove 202 as shown in fig. 11B. Thereafter, when the grinding wheel 16 is further rotated by 120 °, the dresser 113 starts to form a dressing groove 203 as shown in fig. 11C. Thereafter, the dressers 111 to 113 simultaneously form the dressing grooves 201 to 203 until the dresser 111 finishes forming the dressing groove 201 (i.e., the dresser 111 reaches the right end position (index value "W") of the grinding wheel 16). Next, after the formation of the dressing groove 201 by the dresser 111 is completed, when the grinding wheel 16 rotates by 120 °, the formation of the dressing groove 202 by the dresser 112 is completed, and when the grinding wheel 16 further rotates by 120 °, the formation of the dressing groove 203 by the dresser 113 is completed, thereby completing the formation of the three dressing grooves 201 to 203.

Although not shown, the trimming grooves 211 to 213 are formed simultaneously by the trimmers 111 to 113 in the circuit in the same manner as the outward path shown in FIGS. 11A to 11C. Specifically, first, the dresser 113 starts forming the dressing groove 211. Thereafter, when the grinding wheel 16 rotates by 120 °, the dresser 112 starts forming the dressing groove 212. Thereafter, when the grinding wheel 16 is further rotated by 120 °, the dresser 111 starts forming the dressing groove 213. Thereafter, the dressers 111 to 113 simultaneously form the dressing grooves 211 to 213 until the dresser 113 finishes forming the dressing groove 211 (i.e., the dresser 113 reaches the left end position (coordinate value "0") of the grinding wheel 16). Next, after the formation of the trimming groove 211 by the dresser 113 is completed, when the grinding wheel 16 rotates by 120 °, the formation of the trimming groove 212 by the dresser 112 is completed, and when the grinding wheel 16 further rotates by 120 °, the formation of the trimming groove 213 by the dresser 111 is completed, thereby completing the formation of the three trimming grooves 211 to 213.

In this way, a plurality of trimming grooves (three trimming grooves 201 to 203 and three trimming grooves 211 to 213) can be formed in pairs as in fig. 4B by the trimming method according to the present example (i.e., the trimming apparatus 100 shown in fig. 9).

Further, according to the dressing method according to the present example (i.e., the dressing apparatus 100 shown in fig. 9), since it is only necessary to reciprocate the rotating body provided with the plurality of dressers once in the left-right direction, it is possible to form the plurality of dressing grooves in pairs in a shorter time.

Further, according to the dressing method according to the present example (i.e., the dressing apparatus 100 shown in fig. 9), since the plurality of dressers are disposed at different angular positions of the rotating body from each other, the interval in the left-right direction between the dressers can be minimized (i.e., DL/Z). This enables further reduction in the size in the left-right direction occupied by the plurality of trimmers. That is, the trimming device 100 can be made compact. Further, the amount of movement of the plurality of dressers (the rotating body provided with the plurality of dressers) in the left-right direction can be reduced, and the plurality of dressing grooves can be formed in pairs in a shorter time.

Although three dressers 111 to 113 are provided in the dressing apparatus 100 shown in fig. 9, four or more dressers may be provided at different angular positions (circumferential positions) of the rotating body 115 to form four or more pairs of multiple dressing grooves. The rotating body 115 provided with the trimmers 111-113 may be reciprocated a plurality of times in the left-right direction to form a plurality of trimming grooves of four or more pairs.

[ 4 th example of dressing apparatus ]

Next, referring to fig. 12, a 4 th example of the finisher 100 according to the present embodiment will be described.

Fig. 12 is a diagram schematically showing example 4 of the configuration of the finisher 100 according to the present embodiment.

The dressing apparatus 100 according to the present example is different from example 1 shown in fig. 2 in that the rotational position detecting device 140 is omitted.

The controller 150 controls the driving mechanism 120 so that the dresser 110 performs the dressing operation of the grinding wheel 16 at a preset dressing stroke DS and dressing speed V. Specifically, the controller 150 arranges the dresser 110 at a position corresponding to a preset dressing stroke DS, and reciprocates the dresser 110 from the position in the left-right direction at a preset dressing speed V a plurality of times (i.e., a number of times corresponding to the number of dressing grooves formed in the grinding wheel 16) in accordance with the dressing operation.

In addition, the dressing speed V is an absolute speed at which the dresser 110 is moved in the left-right direction, which is different from the dressing feed amount DL depending on the number of revolutions of the grinding wheel 16. The dressing stroke DS is a stroke amount for moving the dresser 110 in the left-right direction during the dressing operation of the grinding wheel 16. Specifically, the dressing stroke DS is set to be equal to or greater than the width W of the grinding wheel 16, and is a value obtained by adding the width W of the grinding wheel 16 to the idle stroke amount before the grinding wheel 16 comes into contact with the grinding wheel.

[ 4 th example of dressing method ]

Next, a dressing method (example 4 of the dressing method according to the present embodiment) performed using the dressing apparatus 100 shown in fig. 12 will be described with reference to fig. 13A and 13B.

Fig. 13A and 13B are diagrams for explaining example 4 of the trimming method according to the present embodiment. Specifically, fig. 13A is a diagram schematically showing the operation of the dresser 110 when the dressing device 100 shown in fig. 12 is used to perform a dressing operation on the grinding wheel 16. Fig. 13B is a conceptual diagram illustrating the flow of the respective steps (run-up step S0, dressing step S1, and idling step S2) when dressing operation is performed on the grinding wheel 16 using the dressing apparatus 100 shown in fig. 12.

As described above, in the dressing apparatus 100 according to the present example, since the rotational position detecting device 140 of the grinding wheel 16 is omitted, the controller 150 cannot synchronize the operation of the dresser 110 with the rotational operation of the grinding wheel 16. Therefore, in this example, the dressing speed V, the dressing stroke DS, and the rotational speed ω of the grinding wheel are adjusted in advance so that the plurality of dressing grooves in pairs similar to those in fig. 4B can be formed only by reciprocating the dresser 110 in the left-right direction. Hereinafter, the description will be specifically made.

In this example, the following description is made on the assumption that the trimming stroke DS and the trimming speed V are default values DSd and Vd. Similarly, the description will be made on the premise that the rotation speed ω of the grinding wheel 16 is set to the default value ω d.

As shown in fig. 13A, the dresser 110 is driven by the drive mechanism 120 (controlled by the controller 150) and reciprocates in the left-right direction with reference to a position corresponding to the dressing stroke DS, that is, a position (initial position) that is separated from one end (left end in the drawing) toward the other end (right end in the drawing) in the width direction of the grinding wheel 16 by the dressing stroke DS, thereby forming a plurality of dressing grooves in pairs in the grinding wheel 16. Specifically, the finisher 110 performs the following reciprocating process a plurality of times (i.e., the number of pairs of finishing grooves) under the control of the driving mechanism 120 by the controller 150: the dresser moves from the home position (refer to the dresser 110 of a solid line or a single-dot chain line in the figure) toward the grinding wheel 16 at a dressing speed V, and when reaching one end (left end) of the grinding wheel 16 (refer to the dresser 110 of a broken line in the figure), it folds back and moves to the home position at the dressing speed V.

In this case, as shown in fig. 13B, the moving step of the dresser 110 includes: a run-up step S0 from the initial position to the contact with the grindstone 16; a dressing step S1 in which the grinding wheel 16 reciprocates in the width direction while contacting the grinding surface (outer peripheral surface); and an idling step S2 in which the grinding wheel 16 is returned from one end (right end) to the initial position, and is turned back again from the initial position to one end (right end) of the grinding wheel 16. The dresser 110 forms a plurality of dressing grooves in pairs while repeating the reciprocating process including the dressing step S1 and the idling step S2 after the first run-up step S0.

Here, to form a plurality of trimming grooves of a number Z in pairs, it is necessary to shift the phase of the trimming groove formed in the 2 nd and subsequent reciprocating steps by 2 pi/Z rad with respect to the phase of the trimming groove formed in the previous 1 reciprocating step (that is, the circumferential pitch θ of the plurality of trimming grooves). That is, in a certain reciprocating step, the angular position at which contact with the grinding wheel 16 is started needs to be shifted by the circumferential pitch θ of the plurality of dressing grooves from the angular position at which contact with the grinding wheel 16 is first performed in the previous reciprocating step. Hereinafter, the difference between the angular position at which contact with the grinding wheel 16 is started in a certain reciprocating step and the angular position at which contact with the grinding wheel 16 is started in the previous reciprocating step (i.e., the phase difference based on 1 cycle (2 π rad) in the circumferential direction of the grinding wheel 16 generated in the reciprocating step) will be referred to as the phase difference φ generated in the reciprocating step.

The phase difference Φ [ rad ] generated by the reciprocation process can be expressed as the following expression (1) using the number N of revolutions of the grinding wheel 16 during the reciprocation process.

φ＝{N-int(N)}·2π……(1)

Further, int (N) represents an integer part of the number of revolutions N.

The number N of revolutions of the grinding wheel 16 during the reciprocating process can be expressed as the following formula (2) using the rotation speed ω of the grinding wheel 16 and the required time T for the reciprocating process.

N＝ωT……(2)

The required time T for the reciprocating process can be expressed by the following equation (3) using the dressing speed V and the dressing stroke DS.

T＝2DS/V……(3)

Thus, according to equations (2) and (3), the number of revolutions N of the grinding wheel 16 during the reciprocating step can be expressed as the following equation (4) using the revolution speed ω of the grinding wheel 16, the dressing speed V, and the dressing stroke DS.

N＝2ω·DS/V……(4)

The phase difference Φ generated by the reciprocation process can be expressed by using the rotation speed ω of the grinding wheel 16, the dressing speed V, and the dressing stroke DS according to equations (1) and (4). That is, the phase difference Φ can be adjusted by adjusting at least 1 of the rotational speed ω, dressing speed V, and dressing stroke DS of the grinding wheel 16.

If the phase difference Φ is equal to the circumferential pitch θ (2 pi/Z) of the plurality of dressing grooves while the rotation speed ω, the dressing speed V, and the dressing stroke DS of the grinding wheel 16 are set to the default values Vd, DSd, and ω d as described above, the controller 150 causes the dresser 110 to perform the reciprocating process corresponding to Z times (i.e., the dressing process S1 and the solid idling process S2 in fig. 13B) in a state of the default values, thereby forming a plurality of dressing grooves in pairs as shown in fig. 4B.

On the other hand, if there is a difference between the phase difference Φ generated by the reciprocation step and the circumferential pitch θ of the plurality of dressing grooves, it is necessary to change at least 1 of the rotation speed ω, the dressing speed V, and the dressing stroke DS of the grinding wheel 16 from the default values Vd, DSd, and ω d so that the phase difference Φ generated by the reciprocation step is equal to the circumferential pitch θ of the plurality of dressing grooves.

For example, by changing the trimming stroke DS by a trimming stroke conversion correction amount Δ X (see fig. 13A and 13B) corresponding to a phase difference correction amount Δ Φ (which is Φ - θ) obtained by subtracting the circumferential pitch θ from the phase difference Φ, the phase difference Φ can be made equal to the circumferential pitch θ of the plurality of trimming grooves. The dressing stroke conversion correction amount Δ X can be expressed as the following equation (5) using the dressing speed V and the rotation speed ω of the grinding wheel 16.

ΔX＝(V/2ω)·Δφ……(5)

Therefore, by changing the dressing stroke DS to a value (corrected dressing stroke value DSc) obtained by adding the dressing stroke conversion correction amount Δ X to the default value DSd, the controller 150 can form a plurality of dressing grooves in pairs on the grinding wheel 16 by simply causing the dresser 110 to perform the reciprocating process (i.e., the dressing process S1 and the dashed idle process S2 in fig. 13B) at the dressing speed V (Vd) from the initial position (see the dresser 110 in the alternate long and short dash line in fig. 13A) corresponding to the dressing stroke DS (DSc).

In the present example, the dressing stroke DS is changed from the default value DSd, but the phase difference Φ may be made equal to the circumferential pitch θ of the plurality of dressing grooves by changing the dressing speed V or the rotational speed ω of the grinding wheel 16 from the default values Vd and ω d. In the idling step S2, the operation of the dresser 110 may be suspended for a time corresponding to the phase difference correction amount Δ Φ so that the phase difference Φ becomes equal to the circumferential pitch θ of the plurality of dressing grooves. That is, the idle operation S2 may be provided with a pause time corresponding to the phase difference correction amount Δ Φ. In the present example, the dressing stroke DS and the like are changed based on the default state, but the rotational speed ω, the dressing speed V, and the dressing stroke DS of the grinding wheel 16 may be appropriately adjusted within a predetermined range so that the phase difference Φ becomes equal to the circumferential pitch θ of the plurality of dressing grooves.

In this way, in the present example, the rotation speed ω, dressing speed V, and dressing stroke DS of the grinding wheel 16 are set in advance such that the phase difference Φ generated by the reciprocation process becomes equal to the circumferential pitch θ (═ 2 pi/Z) of the plurality of dressing grooves. Thus, the controller 150 can form a plurality of trimming grooves in pairs without using the rotational position detecting device 140.

[ 5 th example of dressing method ]

Next, a dressing method 5 example using the dressing apparatus 100 according to the present embodiment will be described with reference to fig. 14A to 14C.

In this example, as in the case of the above-described dressing methods 1 to 4, a plurality of dressing grooves are formed in pairs on the grinding work surface of the grinding wheel 16 by the dressing apparatus 100, and the same dressing work is performed more than once so as to scan (sweeping) the plurality of formed dressing grooves in pairs.

For example, in the case of the 1 st to 3 rd examples of the dressing apparatus 100 according to the present embodiment, the controller 150 can cause the dresser 110 to perform the dressing operation after the 2 nd time by appropriately synchronizing the angular position of the grinding wheel 16 and the position of the dresser 110 in the left-right direction (the contact position of the grinding wheel 16 in the width direction) based on the detection signal of the rotational position detecting device 140 so as to scan the paired plurality of dressing grooves formed in the dressing operation of the 1 st time. For example, in the dressing apparatus 100 according to example 4 of the present embodiment, the rotational speed ω of the grinding wheel 16, the dressing speed V, and the dressing stroke DS may be set in advance such that the phase difference Φ is equal to the circumferential pitch θ of the plurality of dressing grooves. Thus, the controller 150 can cause the dresser 110 to perform the dressing operation after the 2 nd dressing operation so as to scan the paired dressing grooves formed in the 1 st dressing operation by causing the dresser 110 to perform the reciprocating operation at the dressing speed V from the initial position corresponding to the dressing stroke DS.

Fig. 14A to 14C are views showing example 5 of a dressing method performed by using the dressing apparatus 100 according to the present embodiment. Specifically, fig. 14A to 14C are diagrams showing changes in the trimming grooves formed by further performing the trimming operation so as to scan the plurality of trimming grooves in pairs formed by the 1 st trimming operation in the trimming operations after the 2 nd trimming operation. More specifically, fig. 14A is a view schematically showing the depth of the trimming groove formed by the 1 st trimming operation, fig. 14B is a view schematically showing the depth of the trimming groove after the 2 nd trimming operation, and fig. 14C is a view schematically showing the depth of the trimming groove after the N (3 or more) th trimming operation.

For example, as shown in fig. 14A, in the dressing operation of the 1 st time, the contact depth (feed amount) between the grinding surface of the grinding wheel 16 and the dresser 110 is set to a small value (for example, about 10 μm, preferably less than 10 μm), so that a plurality of shallow dressing grooves are formed in pairs. This is because, if the feed amount in one dressing operation is set to be large in order to form a deep groove at a time, a phenomenon (a crushing phenomenon) in which abrasive grains are crushed or a phenomenon (a falling phenomenon) in which a binder is not subjected to a cutting force and falls off together with the abrasive grains may occur, and thus a deep dressing groove may not be obtained.

Next, as shown in fig. 14B and 14C, the trimming operations after the 2 nd trimming operation are performed so as to scan the trimming groove formed in the 1 st trimming operation. As described above, in the 2 nd dressing operation, the feed amount of the dresser 110 to the grinding work surface of the grinding wheel 16 is also set to be small in order to suppress the chipping phenomenon or the chipping phenomenon. Thus, the depth of the pair of dressing grooves of the grinding wheel 16 is gradually increased each time dressing work is performed.

In this way, in the present example, by further performing the trimming operation so as to scan the formed paired trimming grooves, it is possible to form the deep paired trimming grooves while suppressing the occurrence of the chipping phenomenon, the dropping phenomenon, and the like. Specifically, in one trimming operation, only the trimming groove having a depth of less than 10 μm can be formed, and only the trimming groove having a depth of about 20 to 30 μm can be formed at the maximum, but according to this example, a very deep trimming groove having a depth of more than 100 μm can be formed. Therefore, the grinding wheel 16 subjected to the dressing work by the dressing method of the present example has a very deep groove, and therefore the grinding powder can be discharged to the outside of the grinding wheel through the deep dressing groove. Therefore, the interval at which the dressing operation is performed (i.e., the period from after the dressing operation to the next dressing operation) can be made longer while suppressing clogging of the grindstone 16.

[ method of machining grinding wheel having a plurality of dressing grooves formed in pairs ]

Next, a machining method of machining the workpiece 12 using the grinding wheel 16 having the pair of the plurality of dressing grooves formed by the dressing method according to the present embodiment will be described with reference to fig. 15 and 16.

Fig. 15 is a diagram illustrating an example of a machining method performed using the grinding wheel 16 after the dressing operation is performed by the dressing apparatus 100 according to the present embodiment. Specifically, fig. 15 is a side view showing a state in which periodic pits are formed in the surface of the workpiece 12 using the flat grinder 1 equipped with the grinding wheel 16 subjected to the dressing operation by the dressing apparatus 100 according to the present embodiment.

In this example, the grinding wheel 16 is formed with 4 dressing grooves in pairs (the number Z is 4).

As shown in fig. 15, the workpiece 12 is moved in the X direction by moving the movable table 10 in the X direction (left direction in the figure), and the surface of the workpiece 12 is ground by the rotating grinding wheel 16.

As described above, the grinding surface of the grinding wheel 16 has the dressing peaks 16A formed in the circumferential direction, the number of which is twice the number Z (in the present example, 8 dressing peaks, the number of which is twice the number 4). Therefore, in microscopic observation, 2 · Z continuous pits 12A corresponding to the 2 · Z (═ 8) dressing peak 16A formed on the outer periphery of the grinding wheel 16 are formed in the distance L of movement of the workpiece 12 in the X direction (i.e., the distance of movement of the movable table 10) while the grinding wheel 16 rotates 1 revolution of the surface (ground surface) of the workpiece 12.

The controller 20 of the surface grinding machine 1 can repeatedly grind the portion of the periodic pockets 12A formed in the workpiece 12 by repeatedly reciprocating the movable table 10 while synchronizing the position of the movable table 10 in the X direction with the angular position of the grinding wheel 16, thereby repeatedly grinding the portion of the periodic pockets 12A of the workpiece 12 by the dressing peak 16A of the grinding wheel 16. Therefore, the use of the surface grinder 1 enables formation of periodic pits 12A having a large depth (for example, a depth of several tens μm to several hundreds μm) and continuing in the moving direction on the workpiece 12.

The moving distance L of the movable table 10 per 1 rotation of the grinding wheel 16 can be expressed by the following equation (6) using the moving speed Vt of the movable table 10 and the rotation speed ω g of the grinding wheel 16.

L＝Vt/ωg……(6)

Also, the pitch p in the moving direction (i.e., the X direction) of the periodic pits 12A formed in the work piece 12 can be expressed as the following expression (7).

p＝L/2Z……(7)

For example, when the moving speed Vt of the movable table 10 and the rotation speed ω g of the grinding wheel 16 are set to the conditions of the following expression (8) and the following expression (9), the moving distance L of the movable table 10 per 1 rotation of the grinding wheel 16 is the following expression (10).

Vt＝40[m/min]……(8)

ωg＝1000[rpm]……(9)

L＝0.04[m]……(10)

Thus, the pitch p of the periodic pits 12A formed in the workpiece 12 is expressed by the following equation (11) when the number Z is 4.

p＝0.04/2·4＝0.005[m]＝5[mm]……(11)

Similarly, for example, when 10 pairs of dressing grooves are formed in the grinding wheel 16 (that is, when the number Z is 10), the pitch p is further shortened to 2[ mm ]. For example, when 2 pairs of dressing grooves are formed in the grinding wheel 16 (that is, when the number of dressing grooves Z is 2), the pitch p is 10[ mm ].

As described above, by repeating grinding of the portion of the pocket 12A of the workpiece 12 by the dressing peak of the grinding wheel 16 while synchronizing the dressing peak of the grinding wheel 16 with the pocket 12A formed in the surface of the workpiece 12, the machining method of the present example can form the periodically continuous pocket 12A having a large depth (for example, a depth in the range of 10 μm or more, preferably, a depth of several tens μm to several hundreds μm) and a small fine pitch p (that is, a pocket length) (for example, a depth in the range of 10mm or less, preferably, 5mm or less) on the surface of the workpiece 12.

As described above, the periodically continuous dimples 12A formed by the machining method of the present example have a minute pit length and a large pit depth, and are therefore suitable as an oil reservoir for lubricating oil in the dynamic pressure slide guide surface (sliding surface) of a machine tool.

For example, fig. 16 is a view showing an example of a sliding surface (dynamic pressure slide guide surface) to which a plurality of dimples 12A formed by the machining method shown in fig. 15 can be applied. Specifically, fig. 16 is an X-direction cross-sectional view showing an example of a detailed configuration of the movable table 10 in the surface grinding machine 1.

As shown in fig. 16, the movable table 10 includes a movable table main body 10A and guided leg portions 10B provided at both ends of the lower surface of the movable table main body in the Y direction.

The guided leg portion 10B is disposed on a fixed portion (i.e., the guide rail 14) provided on the surface grinding machine 1.

The lower surface (i.e., the sliding surface 10BS) of the guided leg portion 10B slides on a guide surface 14S (an example of a fixed surface) of the guide rail 14 as the movable table 10 moves in the X direction. That is, the sliding surface 10BS of the guided leg portion 10B corresponds to a dynamic pressure sliding guide surface. Therefore, by applying the processing method shown in fig. 15 to the sliding surface 10BS of the guided leg portion 10B, a plurality of dimples 12A having a large depth and a minute pit length, which are continuously formed in the moving direction of the movable table 10, can be provided. Accordingly, in the stationary state of the movable table 10, the stationary frictional force between the sliding surface 10BS and the guide surface 14S may be increased, and the accuracy of positioning or the like may be deteriorated. Further, although it is generally necessary to perform machining such as manual scraping to form an oil reservoir on the dynamic pressure sliding guide surface, the machining efficiency is extremely low, but since the plurality of dimples 12A can be automatically formed by the surface grinding machine 1, the machining efficiency can be greatly improved.

[ Structure of cylindrical grinder ]

Next, another example of the grinding machine according to the present embodiment (i.e., a cylindrical grinding machine) will be described with reference to fig. 17 and 18.

Fig. 17 is a diagram schematically showing an example of the structure of the cylindrical grinding machine according to the present embodiment. In the drawings, the X direction and the Y direction indicate the horizontal direction, and the Z direction indicates the height direction orthogonal to the X direction and the Y direction. In the figure, the θ 1 direction indicates the rotation direction of the grinding wheel 16, and the θ 2 direction indicates the rotation direction of the workpiece 52.

The cylindrical grinding machine according to the present example is different from the surface grinding machine 1 shown in fig. 1 in that the rotating grinding wheel 16 is brought into contact with the cylindrical workpiece 52 to grind the outer peripheral surface thereof, but is not brought into contact with the plate-shaped workpiece 12.

Hereinafter, the same components as those of the surface grinding machine 1 shown in fig. 1 will be denoted by the same reference numerals, and different portions will be described with emphasis on the description.

In the external grinding machine, the workpiece 52 rotatably supported at both end portions is rotated in the θ 2 direction, and the grindstone 16 is rotated in the θ 1 direction, whereby the outer peripheral surface of the workpiece 52 is ground by the grindstone 16.

In this example, since the grinding wheel 16 having the same structure as the surface grinding machine 1 shown in fig. 1 is also provided, generation of waviness, chatter marks, and the like on the surface of the workpiece 52 to be cut can be suppressed

Fig. 18 is a diagram schematically showing another example of the structure of the cylindrical grinding machine according to the present embodiment. In the drawings, the X direction and the Y direction indicate the horizontal direction, and the Z direction indicates the height direction orthogonal to the X direction and the Y direction. In the figure, the θ 1 direction indicates the rotation direction of the grindstone 16, the θ 2 direction indicates the rotation direction of the workpiece 52, and the θ 3 direction indicates the rotation direction of the adjustment wheel 67.

The cylindrical grinding machine according to the present example is different from the example shown in fig. 17 in that it includes the grinding wheel 16, the regulating wheel 67, and the carrier plate 68, and the outer peripheral surface of the workpiece 52 is ground by sandwiching the workpiece 52 between the grinding wheel 16 and the regulating wheel 67 while the cylindrical workpiece 52 is supported and rotated by the regulating wheel 67 and the carrier plate 68.

Hereinafter, the same components as those of the cylindrical grinding machine shown in fig. 17 will be denoted by the same reference numerals, and different portions will be described with emphasis on the description.

The adjustment wheel 67 has a cylindrical shape, and is disposed with its central axis parallel to the Y direction. The adjustment wheel 67 is rotatably supported and rotates in the θ 3 direction, for example, using a servo motor or the like as a drive force source.

The blade 68 supports the material 52 to be cut from the lower side. The carrier plate 68 is disposed below the region where the workpiece 52 is disposed between the grinding wheel 16 and the regulating wheel 67.

[ Structure of internal grinder ]

Next, another example of the grinding machine (i.e., an internal grinding machine) according to the present embodiment will be described with reference to fig. 19.

Fig. 19 is a diagram schematically showing an example of the structure of the internal grinding machine according to the present embodiment. In the drawings, the X direction and the Y direction indicate the horizontal direction, and the Z direction indicates the height direction orthogonal to the X direction and the Y direction. In the figure, the θ 1 direction indicates the rotation direction of the grindstone 16, and the θ 2 direction indicates the rotation direction of the workpiece 72.

The internal grinding machine according to the present example is different from the surface grinding machine 1 shown in fig. 1 in that it includes the grinding wheel 16 and the grinding wheel rotation shaft 77, and the grinding wheel 16 rotating together with the grinding wheel rotation shaft 77 is brought into contact with the inner peripheral surface of the cylindrical workpiece 72 to grind the inner peripheral surface of the workpiece 72.

In the internal grinding machine, the workpiece 72 supported by a magnet or the like so as to be rotatable about the Y direction as a rotation axis is rotated in the θ 2 direction, and the grinding wheel 16 is rotated in the θ 1 direction, whereby the inner peripheral surface of the workpiece 72 is ground by the grinding wheel 16.

In this example, since the grinding wheel 16 having the same structure as the surface grinding machine 1 shown in fig. 1 is also provided, generation of waviness, chattering, and the like on the surface of the workpiece 72 can be suppressed

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the specific embodiments described above, and various modifications and changes can be made within the scope of the present invention described in the claims.

In addition, the international application claims priority to taiwan region No. 106116131, based on 2017, 5, month 16, the entire contents of which are incorporated herein by reference.

Description of the symbols

1-surface grinding machine, 10-movable table, 10A-movable table main body, 10B-guided foot, 10 BS-sliding surface, 12-material to be cut, 14-guide rail, 14S-guide rail surface (fixed surface), 15-wheel head, 16-wheel, 18-guide rail, 20-control device, 40-display device, 100-dressing device, 110, 111, 112, 113-dresser, 115-rotating body, 120-driving mechanism, 125-rotational position detecting device, 130-rotating mechanism, 131-rotating shaft, 140-rotational position detecting device, 150-controller, 201-203-dressing groove (1 st spiral groove), 211-213-dressing groove (2 nd spiral groove).

Claims

1. A grinding wheel for use in a grinding machine, the grinding wheel comprising:

a plurality of 1 st spiral grooves provided on an outer peripheral surface of the grinding wheel; and

and a plurality of 2 nd spiral grooves provided on the outer peripheral surface and intersecting the plurality of 1 st spiral grooves, respectively.

2. The grinding wheel according to claim 1,

the plurality of 1 st helical grooves being parallel to each other, the plurality of 2 nd helical grooves being parallel to each other,

a movement amount of each 1 st spiral groove of the plurality of 1 st spiral grooves and each 2 nd spiral groove of the plurality of 2 nd spiral grooves in a width direction of one circumference of the outer peripheral surface is 0.1mm or more,

a distance between two 1 st spiral grooves adjacent to each other among the plurality of 1 st spiral grooves and a distance between two 2 nd spiral grooves adjacent to each other among the plurality of 2 nd spiral grooves are both 0.5mm or less in a width direction of the outer circumferential surface,

the spacing is less than the amount of movement.

3. The grinding wheel according to claim 1,

in the 1 st or 2 nd helicoidal groove direction, three or more peaks surrounded by any two 1 st helicoidal grooves of the plurality of 1 st helicoidal grooves and any two 2 nd helicoidal grooves of the plurality of 2 nd helicoidal grooves are provided on one circumference of the outer peripheral surface.

4. The grinding wheel according to claim 1,

the depth of the 1 st and 2 nd spiral grooves is at least 10 μm or more.

5. A grinding machine is characterized in that a grinding machine body is provided with a grinding wheel,

a grinding wheel according to claim 1.

6. A grinding machine as claimed in claim 5 wherein,

further comprises a movable table having a sliding surface sliding with the fixed surface,

the sliding surface has a plurality of pits formed continuously in a periodic manner in a moving direction of the movable table, the pits having a depth of 10[ mu ] m or more and a length of 10mm or less.