CN110769979B

CN110769979B - Dressing method, dressing device, grinding wheel and grinding machine

Info

Publication number: CN110769979B
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: 2023-04-21
Anticipated expiration: 2037-11-17
Also published as: KR20200004885A; TWI632027B; JPWO2018211722A1; TW201741074A; KR102486869B1; WO2018211722A1; JP2018027574A; CN110769979A; JP7009464B2

Abstract

The invention provides a grinding wheel and a grinding machine capable of inhibiting vibration marks and the like from being generated on the surface of a workpiece during grinding. Accordingly, a grinding wheel for a grinding machine is provided with: 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 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 with the fixed surface, and the sliding surface may have a plurality of small recesses formed periodically and continuously in a moving direction of the movable table.

Description

Dressing method, dressing device, grinding wheel and grinding machine

Technical Field

The invention relates to a dressing method, a dressing device, a grinding wheel and a grinding machine.

Background

Conventionally, grinding wheels used in grinding machines have been known (for example, refer to patent document 1).

Technical literature of the prior art

Patent literature

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 be clogged with use, resulting in a decrease in grinding performance. Therefore, a dressing operation (dressing operation) for regenerating grinding performance is sometimes performed.

In dressing work, for example, a dresser having a single diamond is used to form a kerf (dressing groove) smaller than the outer diameter of the abrasive grains (for example, about several μm to several tens μm) on 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 this dressing operation, one dressing groove is formed in a spiral shape on the outer peripheral surface of the grinding wheel by the outward movement of the dresser in the width direction, and the other dressing groove is formed in a spiral shape intersecting the one dressing groove by the return movement. That is, one trimming groove and the other trimming groove intersecting each other form a cone having a substantially diamond-shaped bottom surface, that is, a peak having a substantially quadrangular pyramid shape (hereinafter referred to as a trimming peak).

However, in the grinding wheel regenerated by this dressing operation, the dressing peak formed by the intersection of one dressing groove and the other dressing groove is formed only at two angular positions symmetrical by 180 ° in the circumferential direction (i.e., the rotational direction). Therefore, when grinding is performed using a grinding wheel, the material to be cut is ground near the peak of the dressed peak, and therefore, as the grinding wheel rotates, the range of the material not cut by the dressed peak becomes larger than the portion periodically cut by the dressed peak, and there is a possibility that waviness (chatter marks) may occur on the surface of the material to be cut.

In view of the above problems, an object of the present invention is to provide a technique capable of suppressing generation of chatter marks or the like on the surface of a workpiece during grinding.

Means for solving the technical problems

In order to achieve the above object, one embodiment provides a dressing method for dressing a grinding wheel for a grinding machine, the method including: forming at least two 1 st spiral grooves parallel to each other on the outer peripheral surface of the grinding wheel; and forming two or more 2 nd spiral grooves parallel to each other intersecting with the two or more 1 st spiral grooves, respectively, on an outer peripheral surface of the grinding wheel.

Another embodiment of the present invention provides a dressing apparatus for dressing a grinding wheel for a grinding machine, the dressing apparatus including: a dresser in contact with an outer peripheral surface of the rotating grinding wheel to generate a spiral groove; a rotational position detecting device for detecting a rotational position of the grinding wheel; the controller is used for controlling the operation of the controller,

the controller performs the following steps:

forming at least two 1 st spiral grooves parallel to each other on the outer peripheral surface of the grinding wheel; a kind of electronic device with high-pressure air-conditioning system

And forming two or more 2 nd spiral grooves parallel to each other intersecting with the two or more 1 st spiral grooves on the outer peripheral surface of the grinding wheel.

Effects of the invention

According to the above embodiment, it is possible to provide a technique capable of suppressing generation of vibration marks or the like on the surface of a workpiece during grinding.

Drawings

Fig. 1 is a diagram schematically showing an example of the structure of a surface grinder according to the present embodiment.

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

Fig. 3A is a diagram for explaining example 1 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 view showing an example of a grinding wheel after dressing operation using the dressing apparatus according to the comparative example.

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

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

Fig. 6 is a diagram for explaining a specific manner of disposing 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 diagram schematically showing example 3 of the configuration of the dressing apparatus according to the present embodiment.

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

Fig. 10B is a diagram for explaining a specific manner of disposing 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 view schematically showing a 4 th example 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 machining method performed by using a grinding wheel after performing dressing work 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 pits formed by the processing 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 view 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 diagram schematically showing an example of the structure of a surface grinder 1 according to the present embodiment.

The surface grinder 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 movement direction of the movable table 10, the Y direction indicates the movement direction of the grinding 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 a lower end portion thereof, and is attached to a guide rail 18 so as to be movable in the Y direction and liftable 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 center axis parallel to the Y direction. The grinding wheel 16 moves in the Y-direction and the Z-direction together with the grinding wheel 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 grains or diamond abrasive grains) selected according to the properties of the material to be cut 12, the machining accuracy, and the like, and a bonding agent holding the abrasive grains.

The guide rail 18 moves the grinding wheel head 15 in the Y direction and the Z direction using, for example, two servo motors or the like as driving force sources.

The control device 20 controls the respective parts of the surface grinder 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 CPU, RAM, ROM, I/O, and the like, for example.

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, grinding conditions and the like of the workpiece 12.

[ example 1 of trimming device ]

Next, a dressing apparatus 100 that performs a dressing operation (dressing operation) for a grinding wheel 16 used in the surface grinder 1 will be described with reference to fig. 2.

Fig. 2 is a diagram schematically showing example 1 of the configuration of the dressing apparatus 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 contacts the outer peripheral surface of the rotating grinding wheel 16 (i.e., a work surface for grinding a workpiece, hereinafter, sometimes referred to as a "grinding wheel work surface"), and forms a cutting groove (dressing groove). The dresser 110 has a substantially cylindrical shape and a conical shape at its tip, for example, using single diamond as a raw material. The dresser 110 can form dressing grooves having a smaller width (for example, several μm to several tens μm) than the abrasive grains.

The driving mechanism 120 moves the finisher 110 (specifically, a holding member that holds the finisher 110) 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) using, for example, two servo motors as driving force sources. The driving mechanism 120 includes, for example, a ball screw mechanism, a rack and pinion mechanism, or the like. The driving mechanism 120 adjusts the position in the left-right direction and the position in the up-down direction according to a control instruction from the controller 150. This makes it possible to control the contact state (the depth of the dressing groove) between the dresser 110 and the outer peripheral surface (the grinding wheel working surface) of the grinding wheel 16 mounted on the rotary shaft 131 described later, and the contact position in the width direction (the left-right direction in the drawing) of the grinding wheel 16.

The rotation mechanism 130 rotates the grinding wheel 16 attached to the rotation 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 rotary shaft 131. The rotational position detecting means 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 means is transmitted to the controller 150.

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

[ example 1 of trimming method ]

Next, a dressing method (example 1 of the dressing method according to the present embodiment) performed by 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 illustrate operations of the dressing apparatus 100 illustrated in fig. 2.

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

In fig. 3B and 3C, the trimming grooves formed in the previous steps 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 to 3 rd steps are performed in the following order: first, the left end of the grinding wheel 16 is moved to the right end, and then, the dresser 110 is moved from the right end to the left end. In this example, the movement speed of the dresser 110 in the left-right direction, specifically, the amount of left-right movement of the dresser 110 per one rotation of the grinding wheel 16 (hereinafter, referred to as "dressing feed amount") DL is 1/2 of the width W of the grinding wheel 16 (i.e., dressing feed amount dl=w/2). The angular position (0 ° to 360 °) of the grinding wheel 16 is predetermined, and the rotational position detecting device 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 step 1, first, 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 "0 °" and moves in the rightward direction by the dressing feed amount DL (=w/2). 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 reversely, that is, in the left 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 contact 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 (coordinate value "0") of the grinding wheel 16.

As shown in fig. 3A, the dresser 110 is moved in the rightward direction (upward direction in fig. 3A) by the dressing feed amount DL (=w/2) in the forward direction in step 1, and thereby a spiral dressing groove 201 (see white arrows in the figure) is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °" of the left end of the grinding wheel 16 and ending at the angular position "360 °" (= "0 °") of the right end of the grinding wheel 16. The dressing groove 201 is wound in a spiral shape along the outer peripheral surface of the grinding wheel 16 two times.

As shown in fig. 3A, since the dresser 110 is moved in the left direction (downward direction in fig. 3A) by the dressing feed amount DL (=w/2) in the circuit in step 1, a spiral dressing groove 211 (see black arrow in the figure) is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °" of the right end of the grinding wheel 16 and ending at the angular position "360 °" (= "0 °") of the left end of the grinding wheel 16. The dressing groove 211 is wound in a spiral shape along the outer peripheral surface of the grinding wheel 16 for two turns. The trimming groove 211 intersects with the trimming groove 201.

In step 2, the controller 150 shifts the dresser 110 from step 1 by shifting the phase (the angular position of the grinding wheel 16). 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 in the rightward direction by the dressing feed amount DL (=w/2). 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 reversely, that is, in the left 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 contact the right end position (coordinate value "W") of the grinding wheel 16 at the angular position "120 °" 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 (coordinate value "0") of the grinding wheel 16.

As shown in fig. 3B, the dresser 110 is moved in the rightward direction (upward direction in fig. 3B) by the dressing feed amount DL (=w/2) in the outward route in step 2, and thereby a spiral dressing groove 202 is formed in the outer peripheral surface of the grinding wheel 16, which starts from the angular position "120 °" of the left end of the grinding wheel 16 and ends from the angular position "120 °" of the right end of the grinding wheel 16 (see white arrow in the figure). 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., without intersecting the dressing groove 201). On the other hand, the trimming groove 202 intersects with the trimming groove 211 formed in step 1.

As shown in fig. 3B, the dresser 110 is moved in the loop of step 2 by the dressing feed amount DL (=w/2) in the left direction (downward direction in fig. 3B), and thereby a spiral dressing groove 212 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "120 °" of the right end of the grinding wheel 16 and ending from the angular position "120 °" of the left end of the grinding wheel 16 (in the figure, see 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., without intersecting the dressing groove 211). On the other hand, the trimming groove 212 intersects with the trimming groove 201 formed in step 1 and the trimming groove 202 formed in step 2 (outgoing).

In step 3, the controller 150 moves the dresser 110 further out of phase (the angular position of the grinding wheel 16) from step 2. 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 in the rightward direction by the dressing feed amount DL (=w/2). 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 reversely, that is, in the left 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 contact the right end position (coordinate value "W") of the grinding wheel 16 at the angular position "240 °" 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 (coordinate value "0") of the grinding wheel 16.

As shown in fig. 3C, the dresser 110 is moved in the rightward direction (upward direction in fig. 3C) by the dressing feed amount DL (=w/2) in the forward direction in step 3, and thereby a spiral dressing groove 203 is formed in the outer peripheral surface of the grinding wheel 16, starting from the angular position "240 °" of the left end of the grinding wheel 16 and ending from the angular position "240 °" of the right end of the grinding wheel 16 (see white arrow in the figure). 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 step 1 and the trimming groove 212 formed in step 2.

As shown in fig. 3C, the dresser 110 is moved in the left direction (downward direction in fig. 3C) by the dressing feed amount DL (=w/2) in the circuit of step 3, and thereby a spiral dressing groove 213 is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "240 °" of the right end of the grinding wheel 16 and ending from the angular position "240 °" of the left end of the grinding wheel 16 (in the figure, see 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 groove 213 intersects with the trimming grooves 201 to 203 formed in the 1 st to 3 rd steps.

As shown in fig. 3C, dressing grooves 201 to 203 formed in the outgoing lines in steps 1 to 3 are formed spirally on the outer peripheral surface of the grinding wheel 16 and are arranged parallel to each other at equal intervals (i.e., at the same pitch DP (=dl/3)). That is, three dressing grooves 201 to 203 are formed in the outer peripheral surface (grinding wheel working surface) 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 parallel to 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 in the outer peripheral surface (grinding wheel working surface) of the grinding wheel 16.

As described above, the trimming grooves 201 to 203 intersect with the trimming grooves 211 to 213. Accordingly, 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 where the workpiece 12 is ground by the surface grinder 1.

In the present embodiment, the number Z of the plural trimming grooves (trimming grooves 201 to 203 and trimming grooves 211 to 213) in a pair 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 of stripes. In the present embodiment, the number of bars is 3, and therefore, the phase of "120 °" is changed each time and the finisher 110 is reciprocated three times, but, for example, when the number of bars is 2, the phase of "180 °" is changed each time and the finisher 110 is reciprocated two times. For example, when the number of strips is 4, the phase of "90 °" is changed each time, and the finisher 110 is reciprocated four times. That is, the phase may be changed by "(360/Z) °" each time in accordance with the number Z of pieces, and the finisher 110 may be reciprocated Z times to form a plurality of paired finishing grooves.

[ Effect ]

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

Fig. 4A is a diagram showing an example of the grinding wheel 16 after the dressing operation 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 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 working surface) of the grinding wheel 16.

In addition, the trimming device according to the comparative example of the related art performs only step 1 of the trimming device 100 according to the present embodiment. In order to make the intervals (pitches) between 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 is W/6 (DLc =w/6). Further, black dots in the figure schematically represent the peaks 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 on the outer peripheral surface (grinding wheel working surface) of the grinding wheel 16 after the dressing operation using the dressing apparatus according to the comparative example. In the comparative example, as described above, the dressing feed amount DLc =w/6, and hence the dressing

grooves

201c, 211c are wound in a spiral shape along the outer peripheral surface of the grinding wheel 16 by 6 turns, respectively. Further, the diamond-shaped dressing peaks surrounded by the dressing

grooves

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

In this way, the grinding wheel 16 subjected to dressing operation using the dressing apparatus according to the comparative example has dressing peaks formed only at two angular positions symmetrical by 180 ° on the outer peripheral surface (grinding wheel working surface). Therefore, when the grinding wheel 16 attached to the surface grinder 1 rotates and grinds the workpiece 12, there is a possibility that the portions of the workpiece 12 ground by portions other than the vicinity of the two angular positions forming the dressing peak are hardly ground. In this way, the difference between the portion ground by the dressing peak and the portion hardly ground in the material 12 becomes remarkable, and there is a possibility that waviness or chatter marks (chatter marks) may occur on the surface of the material 12. That is, there is a possibility that the quality of the workpiece 12 may be degraded.

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

Therefore, since the grinding wheel 16 attached to the surface grinder 1 grinds the workpiece 12 with the dressing peaks formed at six angular positions on the outer peripheral surface (grinding wheel working surface) while rotating, occurrence of waviness, vibration, and the like on the surface of the workpiece 12 can be suppressed as compared with the case of the comparative example. Further, by setting the number Z of the formed paired plural dressing grooves to be larger (z+.4), the number (=2·z) of angular positions of the grinding wheel 16 provided with the dressing peak increases, and therefore, occurrence of waviness, chatter marks, and the like on the surface of the workpiece 12 can be further suppressed.

The dressing feed amount DL of the pair of dressing grooves (that is, the movement amount of the dressing grooves 201 to 203, 211 to 213 in the width direction per 1 revolution of the outer peripheral surface of the grinding wheel 16) is more preferably 0.1mm or more. Further, the pitch DP of the paired plural dressing grooves (that is, 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.

[ example 2 of trimming device ]

Next, with reference to fig. 5, a description will be given of example 2 of the dressing apparatus 100 according to the present embodiment.

Fig. 5 is a diagram schematically showing an example 2 of the configuration of the dressing apparatus 100 according to the present embodiment.

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

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

The finishers 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. A specific arrangement of the finishers 111 to 113 will be described below with reference to fig. 6.

Fig. 6 is a diagram for explaining a specific arrangement of the finishers 111 to 113.

As shown in fig. 6, the finishers 111 to 113 are arranged in the left-right direction.

The finisher 112 is disposed at a position offset by a distance L1 in the left direction with respect to the position of the finisher 111 in the left-right direction (specifically, the position of the front end of the finisher 111 forming the finishing groove in the left-right direction). The distance L1 is the sum of the integer multiple (n times) of the trimming feed amount DL and the value of the trimming feed amount DL divided by the number Z (=3) (l1=n·dl+dl/Z (n is an integer of 1 or more)). Thus, when the dressing holders 111 to 113 are integrally moved in the left-right direction by the dressing feed amount DL, the dressing groove formed by the dressing holder 112 is shifted by DL/3 in the width direction of the grinding wheel 16 with respect to the dressing groove formed by the dressing holder 111.

The finisher 113 is disposed at a position offset in the left direction by a distance L2 with respect to the position of the finisher 111 in the left-right direction. The distance L2 is the sum of the integer multiple (m-times) of the trimming feed amount DL and the value of the multiple of the trimming feed amount DL divided by the number of strips Z (=3) (l2=m·dl+2dl/Z (m is an integer greater than n)). Thus, when the dressing holders 111 to 113 are integrally moved in the left-right direction by the dressing feed amount DL, the dressing groove formed by the dressing holder 113 is shifted by 2DL/3 in the width direction of the grinding wheel 16 with respect to the dressing groove formed by the dressing holder 111.

Since a plurality of dressing grooves need to be cut into the abrasive grains of the grinding wheel 16, the intervals (pitches) between the dressing grooves are generally set to be sufficiently smaller than the outer dimensions of the dressing machines 111 to 113. Therefore, as shown by the broken line in fig. 6, the finishers 111 to 113 cannot be simply arranged so as to be shifted by DL/3 in the left-right direction.

[ example 2 of trimming 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 views for explaining example 2 of the trimming method according to the present embodiment. Specifically, fig. 7A to 7C and fig. 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 steps once: at least 1 of the dressers 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 mounted on the rotation shaft 131 (hereinafter, referred to as a "reciprocation process"). Fig. 7A to 7C and fig. 8A to 8C are developed views of the outer peripheral surface (grinding wheel working surface) of the grinding wheel 16 showing the state of the dressing groove formed in the outgoing path and the return path in the reciprocation step.

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

grooves

202 and 203 formed using the

trimmers

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

grooves

212 and 213 formed using the

trimmers

112 and 111 are indicated by solid lines. The reciprocation process in this example is performed in the following order: the trimmers 111 to 113 are integrally moved from the left end to the right end of the grinding wheel 16, and then the trimmers 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 DL is 1/2 of the width W of the grinding wheel 16 (i.e., dressing feed dl=w/2) as in the case of fig. 3A to 3C. In this example, n is not less than 2 and m is not less than 4.

In the forward-and-backward process, the controller 150 controls the driving mechanism 120 so that the rightmost dresser 111 among the dressers 111 to 113 comes into contact with the left end position (coordinate value "0") of the grinding wheel 16 at the angular position "0 °", and moves the dressers 111 to 113 integrally in the rightward direction by the dressing feed amount DL (=w/2). The controller 150 controls the driving mechanism 120 to move the leftmost finisher 113 among the finishers 111 to 113 to the right end position (coordinate value "W").

In the forward route, first, as shown in fig. 7A, a dressing groove 201 is formed by the dresser 111. Specifically, by moving the dresser 111 in the rightward direction (upward direction in fig. 7A) by the dressing feed amount DL (=w/2), a spiral dressing groove 201 (in the figure, reference is made to a white arrow) is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °" of the left end of the grinding wheel 16 and ending at the angular position "360 °" (= "0 °") of the right end of the grinding wheel 16.

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

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

In the circuit in the reciprocation process, the controller 150 controls the driving mechanism 120 so that the leftmost dresser 113 among the dressers 111 to 113 starts to contact the right end position (coordinate value "W") of the grinding wheel 16 at the angular position "0 °", and moves the dressers 111 to 113 integrally in the left direction by the dressing feed amount DL (=w/2). The controller 150 controls the driving mechanism 120 to move the rightmost finisher 111 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 (in the figure, reference is made to a black arrow) is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "0 °" of the right end of the grinding wheel 16 and ending at the angular position "360 °" (= "0 °") of the left end of the grinding wheel 16.

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 (see black arrow in the figure) is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "120 °" of the right end of the grinding wheel 16 and ending from the angular position "120 °" of the left end of the grinding wheel 16.

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 (in the figure, see black arrows) is formed on the outer peripheral surface of the grinding wheel 16, starting from the angular position "240 °" of the right end of the grinding wheel 16 and ending from the angular position "240 °" of the left end of the grinding wheel 16.

In the present example, the

finishers

113, 112, and 111 are sequentially formed with the finishing

grooves

211, 212, and 213 in the circuit, but the present invention is not limited to this embodiment. For example, the trimming groove 213 may be formed by the trimmer 113, the trimming groove 211 may be formed by the trimmer 112, and the trimming groove 212 may be formed by the trimmer 111. For example, the trimming groove 212 may be formed by the trimmer 113, the trimming groove 213 may be formed by the trimmer 112, and the trimming groove 211 may be formed by the trimmer 111.

As described above, by the trimming method (i.e., the trimming device 100 shown in fig. 5) according to the present example, a plurality of pairs of trimming grooves (three trimming grooves 201 to 203 and three trimming grooves 211 to 213) similar to those of fig. 4B can be formed.

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

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

[ example 3 of trimming device ]

Next, with reference to fig. 9, a description will be given of example 3 of the dressing apparatus 100 according to the present embodiment.

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

The dressing apparatus 100 according to the present example is different from the example 1 shown in fig. 2 in that a plurality of (three) trimmers 111 to 113 are provided in place of the trimmer 110 in the same manner as the example 2 shown in fig. 5.

The dressing apparatus 100 according to the present example is different from the dressing apparatus according to example 1 shown in fig. 2 and example 2 shown in fig. 5 in that the dressing apparatuses 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 rotation axis extending in the lateral direction.

The dressing apparatus 100 according to the present example is different from the dressing apparatus according to example 1 shown in fig. 2 and example 2 shown in fig. 5 in that a rotational position detecting device 125 that detects the rotational position of the rotating body 115 is further provided.

The same components as those of the dressing apparatus 100 shown in fig. 2 and 5 are denoted by the same reference numerals, and different portions will be described with emphasis.

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

Fig. 10A and 10B are diagrams for explaining the arrangement of the finishers 111 to 113 in detail. Specifically, fig. 10A is a view when the rotary body 115 is viewed from the left, and fig. 10B is a view when the rotary body 115 is viewed from the front.

In fig. 10B, the trimmer 113 is positioned on the rear surface of the rotary body 115, and is indicated by a broken line.

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

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

As will be described later, the rotating body 115 rotates at a sufficiently fast 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 state where the trimmers 111 to 113 are arranged in the left-right direction can be considered as if viewed from the grinding wheel 16 side rotating at a relatively low speed.

Returning to fig. 9, the driving mechanism 120 further includes, for example, another servomotor and drives the rotary body 115 to rotate. The driving mechanism 120 rotates the rotary body 115 at a sufficiently faster rotational speed than the rotational speed of the grinding wheel 16 by the rotating mechanism 130 (preferably, 10 times or more the rotational speed of the grinding wheel 16 by the rotating mechanism 130). The driving mechanism 120 drives the rotating body 115 provided with the finishers 111 to 113 to move 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).

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 rotary body 115. The rotational position detecting means 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 rotational position detecting means is transmitted to the controller 150.

The controller 150 transmits 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 finishers 111 to 113, which is driven by the driving mechanism 120 to move in the up-down, left-right direction. The controller 150 confirms a state in which the rotary body 115 rotates at a sufficiently high speed with respect to the rotational speed of the grinding wheel 16 based on the detection signal from the rotational position detection device 125, and controls the driving mechanism 120.

[ example 3 of trimming method ]

Next, a dressing method (example 3 of the dressing method according to the present embodiment) performed by 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 illustrate the operation of the dressing apparatus 100 illustrated in fig. 9.

The dressing apparatus 100 according to the present example performs the following steps once: at least 1 of the dressers 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 mounted on the rotation shaft 131 (hereinafter, referred to as a "reciprocation process"). Fig. 11A to 11C are developed views of the outer peripheral surface (grinding wheel working surface) of the grinding wheel 16 showing the state of the dressing groove formed in the outgoing path in the reciprocation process.

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

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

As described above, the trimming method according to the present example (i.e., the trimming device 100 shown in fig. 9) can form a plurality of pairs of trimming grooves (three trimming grooves 201 to 203 and three trimming grooves 211 to 213) similar to those of fig. 4B.

Further, according to the dressing method (i.e., the dressing apparatus 100 shown in fig. 9) according to the present example, the rotating body provided with the plurality of trimmers is required to be reciprocated in the left-right direction only once, so that a plurality of pairs of dressing grooves can be formed in a shorter time.

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

In addition, although three trimmers 111 to 113 are provided in the trimming device 100 shown in fig. 9, four or more trimmers may be provided at different angular positions (circumferential positions) of the rotary body 115 to form four or more pairs of a plurality of trimming grooves. The rotary body 115 provided with the finishers 111 to 113 may be reciprocated in the left-right direction a plurality of times to form four or more pairs of a plurality of finishing grooves.

[ example 4 of trimming device ]

Next, a description will be given of a 4 th example of the dressing apparatus 100 according to the present embodiment with reference to fig. 12.

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

The dressing apparatus 100 according to the present example differs from the 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 carries out dressing operation of the grinding wheel 16 at a dressing stroke DS and a dressing speed V set in advance. Specifically, the controller 150 arranges the dresser 110 at a position corresponding to the preset dressing stroke DS, and causes the dresser 110 to reciprocate from this 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) corresponding to 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 contact with the grinding wheel 16.

[ example 4 of trimming method ]

Next, a dressing method (example 4 of the dressing method according to the present embodiment) performed by 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 dressing the grinding wheel 16 by using the dressing apparatus 100 shown in fig. 12. Fig. 13B is a conceptual diagram showing a flow of each step (the running-up step S0, the dressing step S1, and the idling step S2) when the dressing operation is performed on the grinding wheel 16 using the dressing apparatus 100 shown in fig. 12.

As described above, since the dressing apparatus 100 according to the present example omits the rotational position detection device 140 of the grinding wheel 16, 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 pairs of a plurality of dressing grooves similar to those of fig. 4B can be formed by merely reciprocating the dresser 110 in the left-right direction. Hereinafter, specific description will be made.

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

As shown in fig. 13A, the dresser 110 is driven by the driving 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) separating the dressing stroke DS 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, thereby forming a plurality of dressing grooves in pairs on the grinding wheel 16. Specifically, the finisher 110 performs the following reciprocation step a plurality of times (i.e., the number of pairs of finishing grooves) under the control of the controller 150 to the driving mechanism 120: when the dressing speed V moves from the initial position (see the full line or the one-dot chain line dresser 110 in the figure) toward the grinding wheel 16 and reaches one end (left end) of the grinding wheel 16 (see the broken line dresser 110 in the figure), the dressing speed V moves to the initial position while turning back.

At this time, as shown in fig. 13B, the moving process of the finisher 110 includes: a running-up step S0 from the initial position to the contact with the grinding wheel 16; a dressing step S1 of reciprocating in the width direction while contacting the grinding surface (outer peripheral surface) of the grinding wheel 16; and an idling step S2 of returning from one end (right end) of the grinding wheel 16 to the initial position and turning back again from the initial position to reach one end (right end) of the grinding wheel 16. After the initial running-up step S0, the finisher 110 forms a plurality of pairs of finishing grooves while repeating the reciprocation step including the finishing step S1 and the idling step S2.

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

The phase difference Φrad generated by the reciprocation process can be expressed as the following formula (1) using the number N of revolutions of the grinding wheel 16 during the reciprocation process.

φ＝{N-int(N)}·2π…… (1)

In addition, int (N) represents an integer part of the revolution number N.

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

N＝ωT…… (2)

The required time T for the reciprocation step can be expressed as the following expression (3) using the trimming speed V and the trimming stroke DS.

T＝2DS/V…… (3)

Thus, according to the formulas (2) and (3), the number of revolutions N of the grinding wheel 16 during the reciprocation process can be expressed as the following formula (4) using the rotational 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 step can be expressed by the rotational speed ω, dressing speed V, and dressing stroke DS of the grinding wheel 16 according to the 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 rotational speed ω, dressing speed V, and dressing stroke DS of the grinding wheel 16 are set to the default values Vd, DSd, and ωd, and if the phase difference Φ is equal to the circumferential pitch θ (=2pi/Z) of the plurality of dressing grooves as described above, the controller 150 causes the dresser 110 to perform the reciprocation step (i.e., the dressing step S1 and the idling step S2 in solid line in fig. 13B) corresponding to the number Z of times in the default value state, and thereby a plurality of dressing grooves in pairs as shown in fig. 4B can be formed.

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

For example, by changing the trimming stroke DS by the trimming stroke conversion correction amount Δx (refer to fig. 13A and 13B) corresponding to the phase difference correction amount ΔΦ (=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 Δx can be expressed as the following expression (5) using the dressing speed V and the rotational 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) in which the dressing stroke conversion correction amount Δx is added to the default value DSd, the controller 150 can form a plurality of paired dressing grooves on the grinding wheel 16 by merely causing the dresser 110 to reciprocate at the dressing speed V (=vd) from the initial position (refer to the dresser 110 of the one-dot chain line in fig. 13A) corresponding to the dressing stroke DS (=dsc) (i.e., the dressing process S1 in fig. 13B and the idling process S2 of the broken line).

In the present example, the dressing stroke DS is changed from the default value DSd, but the dressing speed V or the rotational speed ω of the grinding wheel 16 may be changed from the default values Vd and ωd, so that the phase difference Φ is equal to the circumferential pitch θ of the plurality of dressing grooves. In the idling step S2, the operation of the dresser 110 may be suspended for a time corresponding to the phase difference correction amount ΔΦ so that the phase difference Φ may be equal to the circumferential pitch θ of the plurality of dressing grooves. That is, a pause time corresponding to the phase difference correction amount ΔΦ may be set in the idling step S2. In the present example, the dressing stroke DS is 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 rotational speed ω, dressing speed V, and dressing stroke DS of the grinding wheel 16 are set in advance so that the phase difference Φ generated by the reciprocation process is equal to the circumferential pitch θ (=2pi/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.

[ example 5 of finishing method ]

Next, a description will be given of a 5 th example of a trimming method performed using the trimming device 100 according to the present embodiment, with reference to fig. 14A to 14C.

In this example, as in the above-described examples 1 to 4 of the dressing method, a plurality of paired dressing grooves are formed on the grinding surface of the grinding wheel 16 by the dressing apparatus 100, and the same dressing operation is performed more than once so as to scan (sweep) the plurality of paired dressing grooves that have been formed.

For example, in the case of examples 1 to 3 of the dressing apparatus 100 according to the present embodiment, the controller 150 can perform the dressing operation 2 nd and subsequent times so that the dressing operation 110 scans the paired plural dressing grooves formed in the dressing operation 1 st time by appropriately synchronizing the angular position of the grinding wheel 16 with the position in the left-right direction of the dresser 110 (the contact position in the width direction of the grinding wheel 16) based on the detection signal of the rotational position detection device 140. In the case of the dressing apparatus 100 according to example 4 of the present embodiment, for example, the rotational speed ω of the grinding wheel 16, the dressing speed V, and the dressing stroke DS need only be set in advance so that the phase difference Φ becomes equal to the circumferential pitch θ of the plurality of dressing grooves. Thus, the controller 150 can cause the finisher 110 to perform the finishing operation 2 nd and subsequent times by scanning the paired plurality of finishing grooves formed in the 1 st finishing operation, only by causing the finisher 110 to perform the reciprocation process at the finishing speed V from the initial position corresponding to the finishing stroke DS.

Fig. 14A to 14C are diagrams showing example 5 of a dressing method performed 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 in such a manner that the pairs of the plurality of trimming grooves formed by the 1 st trimming operation are scanned in the trimming operation 2 nd and later. More specifically, fig. 14A is a diagram schematically showing the depth of the trimming groove formed by the 1 st trimming operation, fig. 14B is a diagram schematically showing the depth of the trimming groove after the 2 nd trimming operation, and fig. 14C is a diagram schematically showing the depth of the trimming groove after the N (i.e. 3) th trimming operation.

For example, as shown in fig. 14A, in the dressing operation of the 1 st time, the contact depth (feed amount) of the grinding face of the grinding wheel 16 with 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 paired dressing grooves are formed. This is because, if the amount of feed in one finishing operation is set to be large in order to form a deep groove at one time, a phenomenon in which abrasive grains are broken (breaking phenomenon), a phenomenon in which a binder cannot withstand cutting force and falls off together with the abrasive grains (falling phenomenon), or the like may occur, and a deep finishing groove may not be obtained.

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

In this way, in the present example, by further performing the trimming operation so as to scan the formed paired plural trimming grooves, occurrence of chipping, or the like can be suppressed, and the plural trimming grooves in a deep pair can be formed. Specifically, in a single trimming operation, only trimming grooves having a depth of less than 10 μm can be formed, and at most only trimming grooves having a depth of about 20 μm to 30 μm can be formed, but according to the present example, very deep trimming grooves having a depth of more than 100 μm can be formed. Therefore, the grinding wheel 16 subjected to the dressing operation 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, clogging of the grinding wheel 16 can be suppressed, and 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 set long.

[ method of machining Using grinding wheel with multiple dressing grooves formed in pairs ]

Next, a machining method for machining the workpiece 12 using the grinding wheel 16 having a plurality of paired 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 showing an example of a machining method performed by using the grinding wheel 16 after the dressing operation 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 on the surface of the workpiece 12 using the surface 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, 4 pairs of dressing grooves (number z=4) are formed in the grinding wheel 16.

As shown in fig. 15, by moving the movable table 10 in the X direction (left direction in the drawing), the workpiece 12 is moved in the X direction, 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 twice the number Z (8 dressing peaks twice the number 4 in the case of the present example) formed in the circumferential direction. Therefore, at the time of microscopic observation, 2·z continuous pits 12A corresponding to the dressing peaks 16A of 2·z (=8) formed on the outer periphery of the grinding wheel 16 are formed in the distance L in which the workpiece 12 moves in the X direction (i.e., the moving distance of the movable table 10) during 1 rotation of the grinding wheel 16 on the surface (ground surface) of the workpiece 12.

The control device 20 of the surface grinder 1 can repeatedly perform the reciprocating movement of 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 dressing peak 16A of the grinding wheel 16 on the portion of the periodical pit 12A formed in the workpiece 12. Therefore, using the surface grinder 1, periodic pits 12A having a large depth (for example, a depth of several tens μm to several hundreds μm) continuous in the moving direction can be formed on the workpiece 12.

The moving distance L of the movable table 10 per 1 revolution of the grinding wheel 16 can be expressed by the following expression (6) using the moving speed Vt of the movable table 10 and the rotational speed ωg of the grinding wheel 16.

L＝Vt/ωg…… (6)

The pitch p in the direction of movement (i.e., X direction) of the periodic pit 12A formed in the workpiece 12 can be expressed as the following formula (7).

p＝L/2Z…… (7)

For example, when the moving speed Vt of the movable table 10 and the rotational speed ωg of the grinding wheel 16 are set to the conditions of the following expression (8) and expression (9), the moving distance L of the movable table 10 per 1 revolution of the grinding wheel 16 is expressed by 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 represented by the following formula (11) when the number z=4.

p＝0.04/2·4＝0.005[m]＝5[mm]…… (11)

Similarly, for example, in the case where 10 paired dressing grooves are formed on the grinding wheel 16 (i.e., in the case where the number z=10), the pitch p becomes further shorter to be 2[ mm ]. Further, for example, in the case where 2 pairs of dressing grooves are formed on the grinding wheel 16 (i.e., in the case where the number z=2), the pitch p is 10[ mm ].

As described above, according to the processing method of the present example, by repeatedly grinding the portion of the recess 12A of the workpiece 12 with the dressing peak of the grinding wheel 16 while synchronizing the dressing peak of the grinding wheel 16 with the recess 12A formed on the surface of the workpiece 12, it is possible to form the periodically continuous recess 12A having a large depth (for example, a depth in the range of 10 μm or more, preferably several tens μm to several hundreds μm) and a small fine pitch p (i.e., a pit length) (for example, a range of 10mm or less, preferably 5mm or less) on the ground surface of the workpiece 12.

As described above, the periodically continuous pits 12A formed by the processing method of the present example are small in pit length and large in depth, and are therefore suitable as oil reservoirs for lubricating oil in the dynamic pressure sliding guide surface (sliding surface) of a machine tool.

For example, fig. 16 is a diagram showing an example of a sliding surface (dynamic pressure sliding guide surface) to which a plurality of pits 12A formed by the processing method shown in fig. 15 can be applied. Specifically, fig. 16 is an X-direction cross-sectional view showing an example of a detailed structure of the movable table 10 in the surface grinder 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 end portions in the Y direction of the lower surface of the movable table main body.

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

The lower surface of the guided leg portion 10B (i.e., the sliding surface 10 BS) slides with the 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 foot 10B, a plurality of pits 12A having a large depth and a small pit length, which are continuously formed in the moving direction of the movable table 10, can be provided. In this way, in the stationary state of the movable table 10, the stationary friction force between the sliding surface 10BS and the guide surface 14S may be increased, and the accuracy of positioning may be deteriorated, but by using the plurality of pits 12A as the oil reservoir, the sliding resistance may be reduced, and the accuracy may be improved. In addition, in order to form the oil reservoir on the dynamic pressure sliding guide surface, it is generally necessary to perform a process such as scraping by hand, which is extremely low in processing efficiency, but since the plurality of pits 12A can be automatically formed by the surface grinder 1, the processing efficiency can be greatly improved.

[ Structure of cylindrical grinding machine ]

Next, another example of the grinding machine according to the present embodiment (i.e., 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 figure, the X direction and the Y direction represent horizontal directions, and the Z direction represents a height direction orthogonal to the X direction and the Y direction. In the figure, the θ1 direction indicates the rotation direction of the grinding wheel 16, and the θ2 direction indicates the rotation direction of the workpiece 52.

The cylindrical grinding machine according to the present example differs 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, and is not brought into contact with the plate-shaped workpiece 12.

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

In the cylindrical grinding machine, the outer peripheral surface of the workpiece 52 is ground by the grinding wheel 16 by rotating the workpiece 52 rotatably supported at both end portions in the θ2 direction and rotating the grinding wheel 16 in the θ1 direction.

Since the present example also includes the grinding wheel 16 having the same structure as the surface grinder 1 shown in fig. 1, the occurrence of waviness, vibration, and the like on the surface of the workpiece 52 can be suppressed

Fig. 18 is a view schematically showing another example of the structure of the cylindrical grinding machine according to the present embodiment. In the figure, the X direction and the Y direction represent horizontal directions, and the Z direction represents a height direction orthogonal to the X direction and the Y direction. In the figure, the direction θ1 indicates the rotation direction of the grinding wheel 16, the direction θ2 indicates the rotation direction of the workpiece 52, and the direction θ3 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 the cylindrical grinding machine includes the grinding wheel 16, the adjustment wheel 67, and the carrier 68, and the outer peripheral surface of the workpiece 52 is ground by sandwiching the workpiece 52 with the grinding wheel 16 and the adjustment wheel 67 while supporting the cylindrical workpiece 52 by the adjustment wheel 67 and the carrier 68 to rotate.

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

The regulating wheel 67 has a cylindrical shape, and is arranged with its center axis parallel to the Y direction. The steering wheel 67 is rotatably supported, and rotates in the θ3 direction, for example, using a servomotor or the like as a driving force source.

The pallet 68 supports the material 52 to be cut from the lower side. The support plate 68 is disposed below the disposed region of the workpiece 52 between the grinding wheel 16 and the adjustment wheel 67.

[ Structure of internal grinder ]

Next, a further example of the grinding machine according to the present embodiment (i.e., the internal grinding machine) 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 figure, the X direction and the Y direction represent horizontal directions, and the Z direction represents a height direction orthogonal to the X direction and the Y direction. In the figure, the θ1 direction indicates the rotation direction of the grinding wheel 16, and the θ2 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 the internal grinding machine includes a grinding wheel 16 and a 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 a Y-direction rotation axis is rotated in the θ2 direction, and the grinding wheel 16 is rotated in the θ1 direction, whereby the inner peripheral surface of the workpiece 72 is ground by the grinding wheel 16.

Since the present example also includes the grinding wheel 16 having the same structure as the surface grinder 1 shown in fig. 1, the occurrence of waviness, vibration, and the like on the surface of the workpiece 72 can be suppressed

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

In addition, the international application claims priority based on taiwan patent application No. 106116131 filed on date 16 of 5.2017, the entire contents of which are incorporated herein by reference.

Symbol description

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

Claims

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

forming, on the outer peripheral surface of the grinding wheel, two or more 1 st spiral grooves parallel to each other, by a step of starting two or more steps having different angular positions of contact with the grinding wheel by a dresser; a kind of electronic device with high-pressure air-conditioning system

Forming two or more 2 nd spiral grooves parallel to each other, which intersect with the two or more 1 st spiral grooves, on the outer peripheral surface of the grinding wheel by a step of starting two or more steps having different angular positions of contact with the grinding wheel by a dresser,

four or more cones having diamond-shaped areas surrounded by two dressing grooves of the two or more 1 st spiral grooves and two dressing grooves of the two or more 2 nd spiral grooves as bottom surfaces are formed in the circumferential direction of the grinding wheel.

2. The trimming method according to claim 1, wherein,

the position in the left-right direction of the dresser in contact with the grinding wheel is controlled so as to be synchronized with the rotational position of the grinding wheel.

3. The trimming method according to claim 2, wherein,

the step of forming the two or more 1 st spiral grooves and the step of forming the two or more 2 nd spiral grooves are performed again so as to scan the two or more 1 st spiral grooves and the two or more 2 nd spiral grooves that have been formed.

4. A dressing apparatus for dressing a grinding wheel for a grinding machine, comprising:

a dresser in contact with an outer peripheral surface of the rotating grinding wheel to generate a spiral groove;

a rotational position detecting device for detecting a rotational position of the grinding wheel; a kind of electronic device with high-pressure air-conditioning system

The controller is used for controlling the operation of the controller,

the controller performs the following steps:

a step of forming, on the outer peripheral surface of the grinding wheel, two or more 1 st spiral grooves parallel to each other, the two or more steps having different angular positions at which the grinding wheel contacts with the dresser; a kind of electronic device with high-pressure air-conditioning system

Forming two or more 2 nd spiral grooves parallel to each other intersecting with the two or more 1 st spiral grooves on an outer peripheral surface of the grinding wheel by a step of starting two or more steps having different angular positions of contact with the grinding wheel by the dresser,

5. The trimming device according to claim 4, wherein,

the controller controls the position of the dresser in the left-right direction based on the detection signal received from the rotational position detecting device so as to be synchronized with the rotational position of the grinding wheel.

6. The trimming device according to claim 5, wherein,

the controller controls the finisher to perform the following steps: the step of forming the two or more 1 st spiral grooves and the step of forming the two or more 2 nd spiral grooves are performed again so as to scan the two or more 1 st spiral grooves and the two or more 2 nd spiral grooves that have been formed.