US20160236321A1 - Truing method and truing device - Google Patents
Truing method and truing device Download PDFInfo
- Publication number
- US20160236321A1 US20160236321A1 US15/029,931 US201415029931A US2016236321A1 US 20160236321 A1 US20160236321 A1 US 20160236321A1 US 201415029931 A US201415029931 A US 201415029931A US 2016236321 A1 US2016236321 A1 US 2016236321A1
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- US
- United States
- Prior art keywords
- grindstone
- arcuate
- truer
- end surface
- arcuate surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B53/00—Devices or means for dressing or conditioning abrasive surfaces
- B24B53/06—Devices or means for dressing or conditioning abrasive surfaces of profiled abrasive wheels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
- B24B5/36—Single-purpose machines or devices
- B24B5/42—Single-purpose machines or devices for grinding crankshafts or crankpins
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B53/00—Devices or means for dressing or conditioning abrasive surfaces
- B24B53/003—Devices or means for dressing or conditioning abrasive surfaces using at least two conditioning tools
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B53/00—Devices or means for dressing or conditioning abrasive surfaces
- B24B53/06—Devices or means for dressing or conditioning abrasive surfaces of profiled abrasive wheels
- B24B53/062—Devices or means for dressing or conditioning abrasive surfaces of profiled abrasive wheels using rotary dressing tools
Definitions
- the present invention relates to a method of truing a cylindrical grindstone which is used in a grinding machine or the like, and also to a truing apparatus for realizing the truing method.
- a cylindrical grindstone which is used in a grinding machine or the like is subjected to truing for the purposes of elimination of runout of the grinding surface, coincidence with the shape of the article to be processed, and the like.
- the shape of the grindstone is adjusted by using a truer provided with a diamond roll or the like which is higher in hardness than the grindstone.
- truing a work of adjusting the shape of a grindstone
- dressing that of exposing or fracturing abrasive grains of a grindstone to resharpen a grindstone
- truing both a work of adjusting the shape of a grindstone, and a work of adjusting the shape of a grindstone and exposing or fracturing abrasive grains of the grindstone are called truing.
- Patent Reference 1 describes a truing apparatus in which truing is performed by relatively moving a truer that is rotated about a truer rotation axis parallel to a grindstone rotation axis of a cylindrical grindstone, along the outer circumferential surface of the grindstone, and grindstone arcuate surfaces that are on the both sides of the outer circumferential surface of the grindstone.
- a truer 170 having a roll 170 D which is rotated about a truer rotation axis TJ 1 parallel to a grindstone rotation axis XJ is used, and the truer 170 is moved relative to a grindstone 151 in a state where the truer rotation axis TJ 1 is maintained parallel to the grindstone rotation axis XJ.
- one outer circumference arcuate surface 151 VR is trued from a position PDR on one grindstone arcuate surface 151 ER of the grindstone 151 and in the vicinity of one grindstone end surface 151 TR, toward a grindstone outer circumferential surface 151 G, the grindstone outer circumferential surface 151 G is then trued toward the other grindstone arcuate surface 151 EL, and the other outer circumference arcuate surface 151 VL is then trued.
- the truer 170 After the truer 170 reaches a position PDL on the other grindstone arcuate surface 151 EL and in the vicinity of the other grindstone end surface 151 TL, the truer 170 is separated from the grindstone 151 .
- Patent Reference 1 JP-A-H03-277468
- Patent Reference 1 cannot process an article to be processed in which requires the accuracies of the grindstone end surfaces 151 TR, 151 TL shown in FIG. 9 , and the end surface arcuate surfaces 151 UR, 151 UL) in the vicinity of the grindstone end surfaces.
- the invention has been conducted in view of this. It is an object of the invention to provide a grindstone truing method for adequately processing an article to be processed which requires the accuracies of grindstone end surfaces, and those of grindstone arcuate surfaces in the vicinity of the grindstone end surfaces, and to provide a truing apparatus.
- the truing method and apparatus of the invention employ the following means.
- one aspect of the invention is a truing method which performs truing by using: first and second truers which trues a cylindrical grindstone that is rotated about a grindstone rotation axis to grind a workpiece; a moving unit which is configured to change a relative position between the first truer and the grindstone, and a relative position between the second truer and the grindstone; and a controlling unit which is configured to control the moving unit, wherein the first truer has a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis, the second truer has a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis, the grindstone has: a grindstone outer circumferential surface which is a surface that is parallel to the grindstone rotation axis; grindstone end surfaces which are surfaces that are perpendicular to the grindstone rotation axis; and grindstone arcuate surfaces which are surfaces in boundaries between the grindstone outer
- truing is performed by using two truers, i.e., the first truer having the first roll which is rotated about the first truer rotation axis that is parallel to the grindstone rotation axis, and the second truer having the second roll which is rotated about the second truer rotation axis that is perpendicular to the grindstone rotation axis.
- the grindstone arcuate surfaces are divided into the outer circumference arcuate surfaces which are on the side close to the grindstone outer circumferential surface, and the end surface arcuate surfaces which are on the sides close to the grindstone end surfaces, the grindstone outer circumferential surface and the outer circumference arcuate surfaces are trued by the first truer, and the grindstone end surfaces and the end surface arcuate surfaces are trued by the second truer.
- the grindstone outer circumferential surface, the grindstone end surfaces, and the grindstone arcuate surfaces can be adequately trued without causing the grindstone and the first truer, and the grindstone and the second truer to interfere with each other. Therefore, it is possible to adequately process an article to be processed which requires the accuracies of grindstone end surfaces, and those of the grindstone arcuate surfaces in the vicinity of the grindstone end surfaces.
- one of the outer circumference arcuate surfaces is trued from a position remotest from the grindstone outer circumferential surface in the one outer circumference arcuate surface, toward a position closest to the grindstone outer circumferential surface in the one outer circumference arcuate surface
- the grindstone outer circumferential surface is then trued from a position closest to the one outer circumference arcuate surface in the grindstone outer circumferential surface, toward a position closest to the other outer circumference arcuate surface in the grindstone outer circumferential surface
- the other outer circumference arcuate surface is then trued from a position closest to the grindstone outer circumferential surface in the other outer circumference arcuate surface, toward a position remotest from the grindstone outer circumferential surface in the other outer circumference arcuate surface.
- one of the end surface arcuate surfaces is trued from a position remotest from one of the grindstone end surfaces in the one end surface arcuate surface, toward a position closest to the one grindstone end surface in the one end surface arcuate surface, and the one grindstone end surface is then trued from a position closest to the one end surface arcuate surface in the one grindstone end surface, toward a position remotest from the one end surface arcuate surface in the one grindstone end surface, and the other end surface arcuate surface is trued from a position remotest from the other grindstone end surface in the other end surface arcuate surface, toward a position closest to the other grindstone end surface in the other end surface arcuate surface, and the other grindstone end surface is then turned from a position closest to the other end surface arcuate surface in the other grindstone end surface, toward a position remotest from the other end surface arcuate surface in the other grindstone end surface.
- truing is performed by using the first truer in the sequence of the one outer circumference arcuate surface, the grindstone outer circumferential surface, and the other outer circumference arcuate surface, and truing is performed by using the second truer in the sequence of the one end surface arcuate surface and the one grindstone end surface, and in the sequence of the other end surface arcuate surface and the other grindstone end surface.
- all the surfaces which are to be trued i.e., the grindstone outer circumferential surface, the one grindstone end surface, the other grindstone end surface, the one outer circumference arcuate surface, the other outer circumference arcuate surface, the one end surface arcuate surface, and the other end surface arcuate surface can be trued in an adequate direction and in a shorter period of time.
- the first truer is relatively moved from a side of the one end surface arcuate surface so as to be moved along a first virtual arc which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface, the first virtual arc being in contact with the grindstone arcuate surface at a boundary position between the one outer circumference arcuate surface and the one end surface arcuate surface, the first virtual arc having a first diameter.
- the second truer when the second truer is made relatively close to the grindstone toward the position remotest from the grindstone end surface in the one end surface arcuate surface, the second truer is relatively moved from a side of the one outer circumference arcuate surface so as to be moved along a second virtual arc which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface, the second virtual arc being in contact with the grindstone arcuate surface at the boundary position between the one outer circumference arcuate surface and the one end surface arcuate surface, the second virtual arc having a second diameter.
- the second truer when the second truer is made relatively close to the grindstone toward the position remotest from the grindstone end surface in the other end surface arcuate surface, the second truer is relatively moved from a side of the other outer circumference arcuate surface so as to be moved along a third virtual arc which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface, the third virtual arc being in contact with the grindstone arcuate surface at a boundary position between the other outer circumference arcuate surface and the other end surface arcuate surface, the third virtual arc having a third diameter.
- the first truer when truing of the one outer circumference arcuate surface is started by the first truer, the first truer is relatively moved so as to be moved along the first virtual arc; when truing of the one end surface arcuate surface is started by the second truer, the second truer is relatively moved so as to be moved along the second virtual arc; and, when truing of the other end surface arcuate surface is started by the second truer, the second truer is relatively moved so as to be moved along the third virtual arc.
- the boundary positions functioning as a place connecting a place trued by the first truer with that trued by the second truer, and between the one outer circumference arcuate surface and the one end surface arcuate surface, and between the other outer circumference arcuate surface and the other end surface arcuate surface can be trued more smoothly and more uniformly.
- the boundary position which is between the outer circumference arcuate surface and the end surface arcuate surface in the grindstone arcuate surface is a position where a first virtual line that passes through a center of an arc of the grindstone arcuate surface before truing, and that has an angle of 45 degrees with respect to the grindstone rotation axis, intersects with the grindstone arcuate surface.
- the boundary position between the outer circumference arcuate surface and the end surface arcuate surface can be set to an adequate position.
- the truing amounts (amounts in the arcuate direction) of the arcuate portions (grindstone arcuate surfaces) of the first truer and the second truer are the same, and therefore excellent accuracies of the arcuate portions of the grindstone (grindstone arcuate surfaces) can be attained.
- the boundary position which is between the outer circumference arcuate surface and the end surface arcuate surface in the grindstone arcuate surface is a position where, in a case where a depth by which the grindstone outer circumferential surface is to be trued is indicated as ⁇ D, and a depth by which the grindstone end surface is to be trued is indicated as ⁇ W, a second virtual line intersects with the grindstone arcuate surface, the second virtual line that passes through a center of an arc of the grindstone arcuate surface before truing, and a center of the arc after truing which is a position that is further separated by ⁇ W in a direction separating from the grindstone end surface from a position that is moved from the center of the arc before truing by ⁇ D in a direction separating from the grindstone outer circumferential surface.
- the boundary position between the outer circumference arcuate surface and the end surface arcuate surface can be set to an adequate position corresponding to the machining allowance due to truing.
- the truing amounts (amounts in the arcuate direction) of the arcuate portions (grindstone arcuate surfaces) of the first truer and the second truer are set to values respectively corresponding to the truing depths of the first truer and the second truer, excellent accuracies of the arcuate portions of the grindstone (grindstone arcuate surfaces) can be attained.
- An aspect of the invention is a truing apparatus comprising: a first truer which is disposed for truing a cylindrical grindstone that is rotated about a grindstone rotation axis to grind a workpiece, and which has a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis; a second truer which is disposed for truing the grindstone, and which has a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis; a moving unit which is configured to change a relative position between the first truer and the grindstone, and a relative position between the second truer and the grindstone; and a controlling unit which is configured to control the moving unit, wherein, by using the moving unit and the controlling unit, based on the above-described truing method, the truing apparatus trues the grindstone outer circumferential surface, the grindstone end surfaces, and the grindstone arcuate surfaces of the grindstone.
- FIG. 1(A) is a plan view illustrating an example of the entire configuration of a grinding machine including the truing apparatus of the invention
- FIG. 1(B) is a side view of the grinding machine (a view in which a tailstock is omitted).
- FIG. 2 is a perspective view illustrating approximate shapes and positional relationships of a grindstone (a fragmentary sectional view), a first truer, and a second truer.
- FIG. 3 is a sectional view illustrating surfaces of a grindstone, i.e., a grindstone outer circumferential surface, grindstone end surfaces, and grindstone arcuate surfaces (outer circumference arcuate surfaces and end surface arcuate surfaces).
- a grindstone i.e., a grindstone outer circumferential surface, grindstone end surfaces, and grindstone arcuate surfaces (outer circumference arcuate surfaces and end surface arcuate surfaces).
- FIG. 4 is a view illustrating a truing method of a first embodiment.
- FIG. 5 is a view illustrating the truing method of the first embodiment.
- FIG. 6 is a view illustrating a truing method of a second embodiment.
- FIG. 7 is a view illustrating the truing method of the second embodiment.
- FIG. 8 is a view illustrating an example of a method for setting arc boundary positions functioning as boundaries between outer circumference arcuate surfaces and end surface arcuate surfaces.
- FIG. 9 is a view illustrating an example of a truing method in the related art.
- a horizontal direction which is parallel to a workpiece rotation axis WJ that is the rotation axis of a workpiece (article to be processed) W is the X-axis direction
- a horizontal direction along which a grindstone 50 is cut into the workpiece W is the Z-axis direction
- a vertical upward direction is the Y-axis direction.
- the grinding machine 1 which includes the truing apparatus of the invention has a bed 2 , a headstock 40 , a tailstock 46 , an X-axis movement table 10 , an X-axis direction driving unit 10 M, a Z-axis movement table 20 , a Z-axis direction driving unit 20 M, a grindstone rotation driving unit 50 M, the grindstone 50 , a controlling unit 60 , the first truer 70 , the second truer 80 , etc.
- the illustration of the tailstock 46 is omitted.
- the headstock 40 is fixed onto the bed 2 , and includes a main spindle 41 .
- the main spindle 41 includes a chuck 42 which is rotated about the workpiece rotation axis WJ based on a control signal output from the controlling unit 60 (for example, a numerical control apparatus), and which can grip and release the workpiece W.
- the controlling unit 60 for example, a numerical control apparatus
- the tailstock 46 is fixed onto the bed 2 , and includes a center 47 .
- the center 47 is disposed rotatably about the workpiece rotation axis WJ, movable along the direction (X-axis direction) of the main spindle 41 , and urged in the direction toward the main spindle 41 .
- the workpiece W is, for example, a crankshaft for a vehicle, gripped by the chuck 42 of the main spindle 41 , pressed toward the main spindle 41 and supported by the center 47 , and rotated about the workpiece rotation axis WJ which is parallel to the X-axis, by rotation of the main spindle 41 .
- the X-axis movement table 10 is reciprocally moved in the X-axis direction with respect to the bed 2 along guide rails 10 L that are disposed on the bed 2 along the X-axis direction.
- the X-axis direction driving unit 10 M (for example, an electric motor) rotates a ball screw which is not shown, based on the control signal output from the controlling unit 60 to reciprocally move the X-axis movement table 10 coupled to the ball screw, in the X-axis direction.
- the moving distance is controlled based on a detection signal output from an encoder 10 E which is disposed in the X-axis direction driving unit 10 M.
- the Z-axis movement table 20 is reciprocally moved in the Z-axis direction with respect to the X-axis movement table 10 along guide rails 20 L that are disposed on the X-axis movement table 10 along the Z-axis direction.
- the Z-axis direction driving unit 20 M (for example, an electric motor) rotates a ball screw which is not shown, based on the control signal output from the controlling unit 60 to reciprocally move the Z-axis movement table 20 coupled to the ball screw, in the Z-axis direction.
- the moving distance is controlled based on a detection signal output from an encoder 20 E which is disposed in the Z-axis direction driving unit 20 M.
- the X-axis direction driving unit 10 M and the Z-axis direction driving unit 20 M correspond to the moving unit which changes the relative position between the grindstone 50 and the workpiece W, that between the grindstone 50 and the first truer 70 , and that between the grindstone 50 and the second truer 80 .
- the grindstone rotation driving unit 50 M (for example, an electric motor) generates a rotating driving force for the grindstone, and the generated rotating driving force is transmitted to the grindstone 50 through a power transmitting unit such as a pulley and a belt.
- the grindstone 50 is supported rotatably about the grindstone rotation axis XJ which is parallel to the X-axis. Also the grindstone rotation axis XJ is located on a virtual plane VM which is an XZ-plane including the workpiece rotation axis WJ (see FIG. 1(B) ).
- the controlling unit 60 receives the detection signals output from the encoders 10 E, 20 E, a rotation angle signal of the main virtual plane VM spindle 41 , and the like, and outputs the control signal for rotating the main spindle 41 , that for driving the X-axis direction driving unit 10 M, and that for driving the Z-axis direction driving unit 20 M.
- the first truer 70 has a first roll 70 D (a diamond roll or the like) which is rotated about a first truer rotation axis TJ 1 parallel to the grindstone rotation axis XJ, and a roll driving unit 70 M (for example, an electric motor, see FIG. 2 ) which rotates the first roll 70 D, and is fixed to, for example, the headstock 40 .
- a first roll 70 D a diamond roll or the like
- a roll driving unit 70 M for example, an electric motor, see FIG. 2
- the second truer 80 has a second roll 80 D (a diamond roll or the like) which is rotated about a second truer rotation axis TJ 2 perpendicular to the grindstone rotation axis XJ, and a roll driving unit 80 M (for example, an electric motor, see FIG. 2 ) which rotates the second roll 80 D, and is disposed so as to be movable, for example, along guide rails 80 L in the Z-axis direction with respect to the bed 2 .
- a second roll 80 D a diamond roll or the like
- TJ 2 perpendicular to the grindstone rotation axis XJ
- a roll driving unit 80 M for example, an electric motor, see FIG. 2
- the second truer 80 is moved by the controlling unit 60 in the direction separating from the grindstone 50 so as not to interfere with the workpiece W, and, in the case where the workpiece W is not supported between the main spindle 41 and the center 47 , and the grindstone 50 is to be trued, the second truer 80 is moved by the controlling unit 60 in the direction approaching the grindstone 50 .
- the first truer rotation axis TJ 1 and the second truer rotation axis TJ 2 are located on the virtual plane VM which is an XZ-plane including the workpiece rotation axis WJ.
- all the workpiece rotation axis WJ, the grindstone rotation axis XJ, the first truer rotation axis TJ 1 , and the second truer rotation axis TJ 2 are on the virtual plane VM (virtual plane which is parallel to the X-axis and the Z-axis), all the workpiece rotation axis WJ, the grindstone rotation axis XJ, and the first truer rotation axis TJ 1 are parallel to the X-axis, and the second truer rotation axis TJ 2 is parallel to the Z-axis (perpendicular to the X-axis).
- the grindstone 50 is configured by a grindstone portion 51 which contains bonding parts and abrasive grains, and which is formed into a cylindrical shape, and a disk-like base portion 52 which holds the grindstone portion 51 .
- a place in which the outer circumferential surface of the grindstone 50 , and the virtual plane VM are in contact with each other, and truing is performed by using the first truer 70 is indicated as a to-be-trued place T 70 , that in which the end surface of the grindstone 50 , and the virtual plane VM are in contact with each other, and truing is performed by using the second truer 80 , and which corresponds to the right side in FIG. 2 is indicated as a to-be-trued place T 80 R, and that in which the end surface of the grindstone 50 , and the virtual plane VM are in contact with each other, and truing is performed by using the second truer 80 , and which corresponds to the left side in FIG. 2 is indicated as a to-be-trued place T 80 L.
- the rotation direction of the grindstone 50 is a rotation direction 50 K shown in FIG. 2
- the first roll 70 D is rotated in a rotation direction 70 K
- the to-be-trued place T 80 R is to be trued
- the second roll 80 D is rotated in a rotation direction 80 KR
- the to-be-trued place T 80 L is to be trued
- the second roll 80 D is rotated in a rotation direction 80 KL.
- FIG. 3 is a sectional view of the grindstone 50 taken along an XZ-plane including the grindstone rotation axis XJ.
- a surface which is the outer surface (surface which is to be in contact with the workpiece W) of the grindstone 50 (grindstone portion 51 ), and which is parallel to the grindstone rotation axis XJ is indicated as a grindstone outer circumferential surface 51 G.
- a surface which is perpendicular to the grindstone rotation axis XJ, and which is on the right side in FIG. 3 is indicated as a grindstone end surface 51 TR, and that which is perpendicular to the grindstone rotation axis XJ, and which is on the left side in FIG. 3 is indicated as a grindstone end surface 51 TL.
- a surface which is a surface at a boundary between the grindstone outer circumferential surface 51 G and the grindstone end surface 51 TR, and which is formed into an arcuate shape in FIG. 3 is indicated as a grindstone arcuate surface 51 ER, and that which is a surface at a boundary between the grindstone outer circumferential surface 51 G and the grindstone end surface 51 TL, and which is formed into an arcuate shape in FIG. 3 is indicated as a grindstone arcuate surface 51 EL.
- the center of the arc of the grindstone arcuate surface 51 ER is indicated as the arc center OR
- that of the arc of the grindstone arcuate surface 51 EL is indicated as the arc center OL.
- the boundary position between the grindstone end surface 51 TR and the grindstone arcuate surface 51 ER is indicated as an end surface boundary position PTR, and that between the grindstone outer circumferential surface 51 G and the grindstone arcuate surface 51 ER is indicated as an outer circumferential boundary position PGR.
- the boundary position between the grindstone end surface 51 TL and the grindstone arcuate surface 51 EL is indicated as an end surface boundary position PTL, and that between the grindstone outer circumferential surface 51 G and the grindstone arcuate surface 51 EL is indicated as an outer circumferential boundary position PGL.
- a point where a first virtual line VTR which has an angle ⁇ R (predetermined angle) with respect to the grindstone rotation axis XJ, and which passes through the arc center OR, and the grindstone arcuate surface 51 ER intersect with each other is indicated as an arc boundary position PER
- a first virtual line VTL which has an angle ⁇ L (predetermined angle) with respect to the grindstone rotation axis XJ, and which passes through the arc center OL, and the grindstone arcuate surface 51 EL intersect with each other is indicated as an arc boundary position PEL.
- the angles ⁇ R, ⁇ L are angles which are adequately set, and, for example, 45 degrees.
- a surface which is a partial surface of the grindstone arcuate surface 51 ER, which is continuous to the grindstone outer circumferential surface 51 G, and which extends from the outer circumferential boundary position PGR to the arc boundary position PER is indicated as an outer circumference arcuate surface 51 FR.
- a surface which is the remaining surface of the grindstone arcuate surface 51 ER, which is continuous to the grindstone end surface 51 TR, and which extends from the end surface boundary position PTR to the arc boundary position PER is indicated as an end surface arcuate surface 51 SR. That is, the grindstone arcuate surface 51 ER is divided at the arc boundary position PER into the outer circumference arcuate surface 51 FR and the end surface arcuate surface 51 SR.
- a surface which is a partial surface of the grindstone arcuate surface 51 EL, which is continuous to the grindstone outer circumferential surface 51 G, and which extends from the outer circumferential boundary position PGL to the arc boundary position PEL is indicated as an outer circumference arcuate surface 51 FL.
- a surface which is the remaining surface of the grindstone arcuate surface 51 EL, which is continuous to the grindstone end surface 51 TL, and which extends from the end surface boundary position PTL to the arc boundary position PEL is indicated as an end surface arcuate surface 51 SL. That is, the grindstone arcuate surface 51 EL is divided at the arc boundary position PEL into the outer circumference arcuate surface 51 FL and the end surface arcuate surface 51 SL.
- the controlling unit controls the grindstone rotation driving unit 50 M to rotate the grindstone 50 , the first truer 70 to rotate the first roll 70 D, and the moving unit (the X-axis direction driving unit 10 M, the Z-axis direction driving unit 20 M, and the like) to move the relative position of the first truer 70 with respect to the grindstone 50 , thereby starting truing by the first truer.
- the moving unit the X-axis direction driving unit 10 M, the Z-axis direction driving unit 20 M, and the like
- the controlling unit controls the second truer 80 to rotate the second roll 80 D, and the moving unit (the X-axis direction driving unit 10 M, the Z-axis direction driving unit 20 M, and the like) to move the relative position of the second truer 80 with respect to the grindstone 50 , thereby starting truing by the second truer.
- the controlling unit controls the moving unit to relatively move the first truer 70 with respect to the grindstone 50 in a state where the first truer rotation axis TJ 1 is maintained parallel to the grindstone rotation axis XJ, thereby truing the outer circumference arcuate surface 51 FR which is a partial surface of the grindstone arcuate surface 51 ER, and which is continuous to the grindstone outer circumferential surface 51 G, the grindstone outer circumferential surface 51 G, and the outer circumference arcuate surface 51 FL which is a partial surface of the grindstone arcuate surface 51 EL, and which is continuous to the grindstone outer circumferential surface 51 G.
- the controlling unit controls the moving unit to relatively move the second truer 80 with respect to the grindstone 50 in a state where the second truer rotation axis TJ 2 is maintained in a direction perpendicular to the grindstone rotation axis XJ, thereby truing the end surface arcuate surface 51 SR which is the remaining surface of the grindstone arcuate surface 51 ER, and which is continuous to the grindstone end surface 51 TR, and the grindstone end surface 51 TR.
- the controlling unit controls the moving unit to relatively move the second truer 80 with respect to the grindstone 50 in a state where the second truer rotation axis TJ 2 is maintained in a direction perpendicular to the grindstone rotation axis XJ, thereby truing the end surface arcuate surface 51 SL which is the remaining surface of the grindstone arcuate surface 51 EL, and which is continuous to the grindstone end surface 51 TL, and the grindstone end surface 51 TL.
- the controlling unit trues the outer circumference arcuate surface 51 FR from the arc boundary position PER that is the position which, in the outer circumference arcuate surface 51 FR (corresponding to the one outer circumference arcuate surface), is remotest from the grindstone outer circumferential surface 51 G, toward the outer circumferential boundary position PGR that is the position which, in the outer circumference arcuate surface 51 FR, is closest to the grindstone outer circumferential surface 51 G.
- the controlling unit trues the grindstone outer circumferential surface 51 G from the outer circumferential boundary position PGR that is the position which, in the grindstone outer circumferential surface 51 G, is closest to the outer circumference arcuate surface 51 FR, toward the outer circumferential boundary position PGL that is the position which, in the grindstone outer circumferential surface 51 G, is closest to the outer circumference arcuate surface 51 FL (corresponding to the other outer circumference arcuate surface).
- the controlling unit trues the outer circumference arcuate surface 51 FL from the outer circumferential boundary position PGL that is the position which, in the outer circumference arcuate surface 51 FL, is closest to the grindstone outer circumferential surface 51 G, toward the arc boundary position PEL that is the position which, in the outer circumference arcuate surface 51 FL, is remotest from the grindstone outer circumferential surface 51 G.
- the controlling unit trues the end surface arcuate surface 51 SR from the arc boundary position PER that is the position which, in the end surface arcuate surface 51 SR (corresponding to the one end surface arcuate surface), is remotest from the grindstone end surface 51 TR (corresponding to the one grindstone arcuate surface), toward the end surface boundary position PTR that is the position which, in the end surface arcuate surface 51 SR, is closest to the grindstone end surface 51 TR.
- the controlling unit trues the grindstone end surface 51 TR from the end surface boundary position PTR that is the position which, in the grindstone end surface 51 TR, is closest to the end surface arcuate surface 51 SR, toward the end surface terminal position PZR that is the position which, in the grindstone end surface 51 TR, is remotest from the end surface arcuate surface 51 SR.
- the controlling unit trues the end surface arcuate surface 51 SL from the arc boundary position PEL that is the position which, in the end surface arcuate surface 51 SL (corresponding to the other end surface arcuate surface), is remotest from the grindstone end surface 51 TL (corresponding to the other grindstone end surface), toward the end surface boundary position PTL that is the position which, in the end surface arcuate surface 51 SL, is closest to the grindstone end surface 51 TL.
- the controlling unit trues the grindstone end surface 51 TL from the end surface boundary position PTL that is the position which, in the grindstone end surface 51 TL, is closest to the end surface arcuate surface 51 SL, toward the end surface terminal position PZL that is the position which, in the grindstone end surface 51 TL, is remotest from the end surface arcuate surface 51 SL.
- the first truer 70 is relatively moved from the side of the end surface arcuate surface 51 SR so as to be moved along a first virtual arc VE 1 which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface 51 ER, which is in contact with the grindstone arcuate surface 51 ER at the arc boundary position PER, and which has a first diameter
- the truing from the arc boundary position PER can be started more smoothly. Therefore, this is more preferable.
- the value of the first diameter is appropriately set.
- the first truer 70 is relatively moved to the side of the end surface arcuate surface 51 SL so as to be moved along a fourth virtual arc VEZ which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface 51 EL, which is in contact with the grindstone arcuate surface 51 EL at the arc boundary position PEL, and which has a fourth diameter
- the truing in the arc boundary position PEL can be ended more smoothly. Therefore, this is more preferable.
- the value of the fourth diameter is appropriately set.
- the second truer 80 is relatively moved from the side of the outer circumference arcuate surface 51 FR so as to be moved along a second virtual arc VE 2 which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface 51 ER, which is in contact with the grindstone arcuate surface 51 ER at the arc boundary position PER, and which has a second diameter
- the truing from the arc boundary position PER can be started more smoothly. Therefore, this is more preferable.
- the value of the second diameter is appropriately set.
- the second truer 80 is relatively moved from the side of the outer circumference arcuate surface 51 FL so as to be moved along a third virtual arc VE 3 which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface 51 EL, which is in contact with the grindstone arcuate surface 51 EL at the arc boundary position PEL, and which has a third diameter
- the truing from the arc boundary position PEL can be started more smoothly. Therefore, this is more preferable.
- the value of the third diameter is appropriately set.
- the truing method of the second embodiment shown in FIG. 6 is different from that of the first embodiment shown in FIG. 4 in that the path in the case where the first truer 70 is made close to the arc boundary position PER, and that in the case where the first truer is separated from the arc boundary position PEL are not paths which extend along the virtual arcs, but those which extend along virtual lines parallel to the grindstone rotation axis XJ.
- the truing method of the second embodiment shown in FIG. 7 is different from that of the first embodiment shown in FIG. 5 in that the path in the case where the second truer 70 is made close to the arc boundary position PER, and that in the case where the second truer is made close to the arc boundary position PEL are not paths which extend along the virtual arcs, but those which extend along virtual lines perpendicular to the grindstone rotation axis XJ.
- the first truer 70 is relatively moved with respect to the grindstone 50 so as to be moved along a virtual line VTA which is parallel to the grindstone rotation axis XJ, and which passes through the arc boundary position PER.
- the first truer 70 can be made relatively close to the grindstone 50 through the simple path.
- the first truer 70 is relatively moved with respect to the grindstone 50 so as to be moved along a virtual line VTB which is parallel to the grindstone rotation axis XJ, and which passes through the arc boundary position PEL. According to the configuration, the first truer 70 can be relatively separated from the grindstone 50 through the simple path.
- the second truer 80 is relatively moved with respect to the grindstone 50 so as to be moved along a virtual line VTC which is perpendicular to the grindstone rotation axis XJ, and which passes through the arc boundary position PER.
- VTC which is perpendicular to the grindstone rotation axis XJ, and which passes through the arc boundary position PER.
- the second truer 80 can be made relatively close to the grindstone 50 through the simple path.
- the second truer 80 is relatively moved with respect to the grindstone 50 so as to be moved along a virtual line VTD which is perpendicular to the grindstone rotation axis XJ, and which passes through the arc boundary position PEL. According to the configuration, the second truer 80 can be made relatively close to the grindstone 50 through the simple path.
- angles ⁇ R, ⁇ L (predetermined angles) of the first virtual lines VTR, VTL with respect to the grindstone rotation axis XJ in the case where the arc boundary positions PER, PEL are to be set are, for example, 45 degrees.
- the below-described setting of angles ⁇ R′, ⁇ L′ (predetermined angles) shown in FIG. 8 is more preferable.
- the truing depth (machining allowance due to truing) in a direction perpendicular to the grindstone rotation axis XJ is set as ⁇ D
- the truing depth (machining allowance due to truing) in the direction parallel to the grindstone rotation axis XJ is set as ⁇ W.
- the center of the arc of the right grindstone arcuate surface before truing is indicated as the arc center OR, and that of the arc of the left grindstone arcuate surface before truing is indicated as the arc center OL.
- a position which is further moved by ⁇ W in the direction separating from the right grindstone end surface, from a position that is moved by ⁇ D from the position of the arc center OR in the direction separating from the grindstone outer circumferential surface is set as a new arc center OR′ which is the center of the arc of the right grindstone arcuate surface after truing.
- a position which is further moved by ⁇ W in the direction separating from the left grindstone end surface, from a position that is moved by ⁇ D from the position of the arc center OL in the direction separating from the grindstone outer circumferential surface is set as a new arc center OL′ which is the center of the arc of the left grindstone arcuate surface after truing.
- An angle ⁇ L′ is identical with the angle ⁇ R′, and therefore its description is omitted.
- a truing apparatus including: a first truer having a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis XJ; a second truer having a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis XJ; a moving unit; and a controlling unit, the apparatus truing the grindstone outer circumferential surface, grindstone end surfaces, and grindstone arcuate surfaces of the grindstone, based on the truing methods which have been described in the embodiments.
- the grindstone end surfaces, and the grindstone arcuate surfaces (end surface arcuate surface) which are continuous to the grindstone end surfaces can be adequately trued, the fracturability of the abrasive grains is improved, and the sharpness of the grindstone is improved.
- the improvement of the sharpness can adequately prevent grinding burn from occurring, and contribute to cost reduction.
- truing is performed in appropriate sequence and route. Therefore, truing can be performed in a shorter period of time, and this can contribute to shortening of the process time and energy saving.
- the invention can cope with processing which is applied to, for example, a crankshaft for a special vehicle, and in which accuracies of grindstone end surfaces are required, reduce the friction resistance of the crankshaft, and contribute to improvement of fuel efficiency of the vehicle.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Grinding-Machine Dressing And Accessory Apparatuses (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
Abstract
In a state where a first truer rotation axis is maintained parallel to a grindstone rotation axis, a grindstone outer circumferential surface, and outer circumference arcuate surfaces which are partial surfaces of grindstone arcuate surfaces, and which are continuous to the grindstone outer circumferential surface are trued by using a first truer. In a state where a second truer rotation axis is maintained in a direction perpendicular to the grindstone rotation axis, grindstone end surfaces, and end surface arcuate surfaces which are remaining surfaces of the grindstone arcuate surfaces, and which are continuous to the grindstone end surfaces are trued by using a second truer.
Description
- The present invention relates to a method of truing a cylindrical grindstone which is used in a grinding machine or the like, and also to a truing apparatus for realizing the truing method.
- A cylindrical grindstone which is used in a grinding machine or the like is subjected to truing for the purposes of elimination of runout of the grinding surface, coincidence with the shape of the article to be processed, and the like. In truing, the shape of the grindstone is adjusted by using a truer provided with a diamond roll or the like which is higher in hardness than the grindstone.
- Usually, a work of adjusting the shape of a grindstone is called truing, and that of exposing or fracturing abrasive grains of a grindstone to resharpen a grindstone is called dressing. In the application, however, both a work of adjusting the shape of a grindstone, and a work of adjusting the shape of a grindstone and exposing or fracturing abrasive grains of the grindstone are called truing.
- For example,
Patent Reference 1 describes a truing apparatus in which truing is performed by relatively moving a truer that is rotated about a truer rotation axis parallel to a grindstone rotation axis of a cylindrical grindstone, along the outer circumferential surface of the grindstone, and grindstone arcuate surfaces that are on the both sides of the outer circumferential surface of the grindstone. - In the truing apparatus described in
Patent Reference 1, a pin portion of a crankshaft is ground by the outer circumferential surface of the cylindrical grindstone, and the arcuate surfaces in the boundaries between the outer circumferential surface and end surfaces of the grindstone, and the end surfaces of the grindstone are not used (the article to be processed does not require the end surfaces of the grindstone). - As shown in
FIG. 9 , therefore, atruer 170 having aroll 170D which is rotated about a truer rotation axis TJ1 parallel to a grindstone rotation axis XJ is used, and thetruer 170 is moved relative to agrindstone 151 in a state where the truer rotation axis TJ1 is maintained parallel to the grindstone rotation axis XJ. - In truing, as shown in
FIG. 9 , one outer circumference arcuate surface 151VR is trued from a position PDR on one grindstone arcuate surface 151ER of thegrindstone 151 and in the vicinity of one grindstone end surface 151TR, toward a grindstone outercircumferential surface 151G, the grindstone outercircumferential surface 151G is then trued toward the other grindstone arcuate surface 151EL, and the other outer circumference arcuate surface 151VL is then trued. After thetruer 170 reaches a position PDL on the other grindstone arcuate surface 151EL and in the vicinity of the other grindstone end surface 151TL, thetruer 170 is separated from thegrindstone 151. - In the truing apparatus described in
Patent Reference 1, a region (region including the grindstone end surface 151TR) extending from the position PDR shown inFIG. 9 to an end surface terminal position PZR, and a region (region including the grindstone end surface 151TL) extending from the position PDL to an end surface terminal position PZL are not trued, and therefore the apparatus cannot cope with processing of an article to be processed which requires the accuracies of the end surfaces of a grindstone. As shown inFIG. 9 , the inner diameter side of theroll 170D of thetruer 170 is projected in the direction of the truer rotation axis TJ1. In the state where the truer rotation axis TJ1 is maintained parallel to the grindstone rotation axis XJ, in a case where the grindstone end surfaces 151TR, 151TL shown inFIG. 9 , and grindstone arcuate surfaces (end surface arcuate surfaces 151UR, 151UL inFIG. 9 ) in the vicinity of the grindstone end surfaces are to be trued, therefore, portions which are projected from theroll 170D interfere with thegrindstone 151, and hence truing cannot be performed. Angles θ1, θ2 indicating the ranges of the end surface arcuate surfaces 151UR, 151UL shown inFIG. 9 are, for example, about 10 degrees. - Therefore, the truing apparatus described in
Patent Reference 1 cannot process an article to be processed in which requires the accuracies of the grindstone end surfaces 151TR, 151TL shown inFIG. 9 , and the end surface arcuate surfaces 151UR, 151UL) in the vicinity of the grindstone end surfaces. - The invention has been conducted in view of this. It is an object of the invention to provide a grindstone truing method for adequately processing an article to be processed which requires the accuracies of grindstone end surfaces, and those of grindstone arcuate surfaces in the vicinity of the grindstone end surfaces, and to provide a truing apparatus.
- In order to solve the problem, the truing method and apparatus of the invention employ the following means.
- Firstly, one aspect of the invention is a truing method which performs truing by using: first and second truers which trues a cylindrical grindstone that is rotated about a grindstone rotation axis to grind a workpiece; a moving unit which is configured to change a relative position between the first truer and the grindstone, and a relative position between the second truer and the grindstone; and a controlling unit which is configured to control the moving unit, wherein the first truer has a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis, the second truer has a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis, the grindstone has: a grindstone outer circumferential surface which is a surface that is parallel to the grindstone rotation axis; grindstone end surfaces which are surfaces that are perpendicular to the grindstone rotation axis; and grindstone arcuate surfaces which are surfaces in boundaries between the grindstone outer circumferential surface and the grindstone end surfaces, and which are formed into an arcuate shape, the truing method comprising: controlling the moving unit by the controlling unit, in a state where the first truer rotation axis is maintained parallel to the grindstone rotation axis, to true, by using the first truer, the grindstone outer circumferential surface, and outer circumference arcuate surfaces which are partial surfaces of the grindstone arcuate surfaces and which are continuous to the grindstone outer circumferential surface; and controlling the moving unit by the controlling unit, in a state where the second truer rotation axis is maintained in a direction perpendicular to the grindstone rotation axis, to true, by using the second truer, the grindstone end surfaces, and end surface arcuate surfaces which are remaining surfaces of the grindstone arcuate surfaces and which are continuous to the grindstone end surfaces.
- In the above configuration, truing is performed by using two truers, i.e., the first truer having the first roll which is rotated about the first truer rotation axis that is parallel to the grindstone rotation axis, and the second truer having the second roll which is rotated about the second truer rotation axis that is perpendicular to the grindstone rotation axis. Moreover, the grindstone arcuate surfaces are divided into the outer circumference arcuate surfaces which are on the side close to the grindstone outer circumferential surface, and the end surface arcuate surfaces which are on the sides close to the grindstone end surfaces, the grindstone outer circumferential surface and the outer circumference arcuate surfaces are trued by the first truer, and the grindstone end surfaces and the end surface arcuate surfaces are trued by the second truer.
- According to the configuration, the grindstone outer circumferential surface, the grindstone end surfaces, and the grindstone arcuate surfaces can be adequately trued without causing the grindstone and the first truer, and the grindstone and the second truer to interfere with each other. Therefore, it is possible to adequately process an article to be processed which requires the accuracies of grindstone end surfaces, and those of the grindstone arcuate surfaces in the vicinity of the grindstone end surfaces.
- In one aspect of the invention, when truing is performed by using the first truer, one of the outer circumference arcuate surfaces is trued from a position remotest from the grindstone outer circumferential surface in the one outer circumference arcuate surface, toward a position closest to the grindstone outer circumferential surface in the one outer circumference arcuate surface, the grindstone outer circumferential surface is then trued from a position closest to the one outer circumference arcuate surface in the grindstone outer circumferential surface, toward a position closest to the other outer circumference arcuate surface in the grindstone outer circumferential surface, and the other outer circumference arcuate surface is then trued from a position closest to the grindstone outer circumferential surface in the other outer circumference arcuate surface, toward a position remotest from the grindstone outer circumferential surface in the other outer circumference arcuate surface.
- When truing is performed by using the second truer, one of the end surface arcuate surfaces is trued from a position remotest from one of the grindstone end surfaces in the one end surface arcuate surface, toward a position closest to the one grindstone end surface in the one end surface arcuate surface, and the one grindstone end surface is then trued from a position closest to the one end surface arcuate surface in the one grindstone end surface, toward a position remotest from the one end surface arcuate surface in the one grindstone end surface, and the other end surface arcuate surface is trued from a position remotest from the other grindstone end surface in the other end surface arcuate surface, toward a position closest to the other grindstone end surface in the other end surface arcuate surface, and the other grindstone end surface is then turned from a position closest to the other end surface arcuate surface in the other grindstone end surface, toward a position remotest from the other end surface arcuate surface in the other grindstone end surface.
- According to the configuration, truing is performed by using the first truer in the sequence of the one outer circumference arcuate surface, the grindstone outer circumferential surface, and the other outer circumference arcuate surface, and truing is performed by using the second truer in the sequence of the one end surface arcuate surface and the one grindstone end surface, and in the sequence of the other end surface arcuate surface and the other grindstone end surface.
- Therefore, all the surfaces which are to be trued, i.e., the grindstone outer circumferential surface, the one grindstone end surface, the other grindstone end surface, the one outer circumference arcuate surface, the other outer circumference arcuate surface, the one end surface arcuate surface, and the other end surface arcuate surface can be trued in an adequate direction and in a shorter period of time.
- In one aspect of the invention, at a start of truing of the one outer circumference arcuate surface, when the first truer is made relatively close to the grindstone toward the position remotest from the grindstone outer circumferential surface in the one outer circumference arcuate surface, the first truer is relatively moved from a side of the one end surface arcuate surface so as to be moved along a first virtual arc which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface, the first virtual arc being in contact with the grindstone arcuate surface at a boundary position between the one outer circumference arcuate surface and the one end surface arcuate surface, the first virtual arc having a first diameter.
- Moreover, at a start of truing of the one end surface arcuate surface, when the second truer is made relatively close to the grindstone toward the position remotest from the grindstone end surface in the one end surface arcuate surface, the second truer is relatively moved from a side of the one outer circumference arcuate surface so as to be moved along a second virtual arc which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface, the second virtual arc being in contact with the grindstone arcuate surface at the boundary position between the one outer circumference arcuate surface and the one end surface arcuate surface, the second virtual arc having a second diameter.
- Moreover, at a start of truing of the other end surface arcuate surface, when the second truer is made relatively close to the grindstone toward the position remotest from the grindstone end surface in the other end surface arcuate surface, the second truer is relatively moved from a side of the other outer circumference arcuate surface so as to be moved along a third virtual arc which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface, the third virtual arc being in contact with the grindstone arcuate surface at a boundary position between the other outer circumference arcuate surface and the other end surface arcuate surface, the third virtual arc having a third diameter.
- According to the configuration, when truing of the one outer circumference arcuate surface is started by the first truer, the first truer is relatively moved so as to be moved along the first virtual arc; when truing of the one end surface arcuate surface is started by the second truer, the second truer is relatively moved so as to be moved along the second virtual arc; and, when truing of the other end surface arcuate surface is started by the second truer, the second truer is relatively moved so as to be moved along the third virtual arc.
- Therefore, the boundary positions functioning as a place connecting a place trued by the first truer with that trued by the second truer, and between the one outer circumference arcuate surface and the one end surface arcuate surface, and between the other outer circumference arcuate surface and the other end surface arcuate surface can be trued more smoothly and more uniformly.
- In an aspect invention of the invention, the boundary position which is between the outer circumference arcuate surface and the end surface arcuate surface in the grindstone arcuate surface is a position where a first virtual line that passes through a center of an arc of the grindstone arcuate surface before truing, and that has an angle of 45 degrees with respect to the grindstone rotation axis, intersects with the grindstone arcuate surface.
- According to the configuration, the boundary position between the outer circumference arcuate surface and the end surface arcuate surface can be set to an adequate position.
- The truing amounts (amounts in the arcuate direction) of the arcuate portions (grindstone arcuate surfaces) of the first truer and the second truer are the same, and therefore excellent accuracies of the arcuate portions of the grindstone (grindstone arcuate surfaces) can be attained.
- In an aspect of the invention, the boundary position which is between the outer circumference arcuate surface and the end surface arcuate surface in the grindstone arcuate surface is a position where, in a case where a depth by which the grindstone outer circumferential surface is to be trued is indicated as ΔD, and a depth by which the grindstone end surface is to be trued is indicated as ΔW, a second virtual line intersects with the grindstone arcuate surface, the second virtual line that passes through a center of an arc of the grindstone arcuate surface before truing, and a center of the arc after truing which is a position that is further separated by ΔW in a direction separating from the grindstone end surface from a position that is moved from the center of the arc before truing by ΔD in a direction separating from the grindstone outer circumferential surface.
- According to the configuration, the boundary position between the outer circumference arcuate surface and the end surface arcuate surface can be set to an adequate position corresponding to the machining allowance due to truing.
- When the truing amounts (amounts in the arcuate direction) of the arcuate portions (grindstone arcuate surfaces) of the first truer and the second truer are set to values respectively corresponding to the truing depths of the first truer and the second truer, excellent accuracies of the arcuate portions of the grindstone (grindstone arcuate surfaces) can be attained.
- An aspect of the invention is a truing apparatus comprising: a first truer which is disposed for truing a cylindrical grindstone that is rotated about a grindstone rotation axis to grind a workpiece, and which has a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis; a second truer which is disposed for truing the grindstone, and which has a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis; a moving unit which is configured to change a relative position between the first truer and the grindstone, and a relative position between the second truer and the grindstone; and a controlling unit which is configured to control the moving unit, wherein, by using the moving unit and the controlling unit, based on the above-described truing method, the truing apparatus trues the grindstone outer circumferential surface, the grindstone end surfaces, and the grindstone arcuate surfaces of the grindstone.
- According to the configuration, it is possible to appropriately realize a truing apparatus which can adequately true the grindstone outer circumferential surface, the grindstone end surfaces, and the grindstone arcuate surfaces without causing the grindstone and the truers to interfere with each other.
-
FIG. 1(A) is a plan view illustrating an example of the entire configuration of a grinding machine including the truing apparatus of the invention, andFIG. 1(B) is a side view of the grinding machine (a view in which a tailstock is omitted). -
FIG. 2 is a perspective view illustrating approximate shapes and positional relationships of a grindstone (a fragmentary sectional view), a first truer, and a second truer. -
FIG. 3 is a sectional view illustrating surfaces of a grindstone, i.e., a grindstone outer circumferential surface, grindstone end surfaces, and grindstone arcuate surfaces (outer circumference arcuate surfaces and end surface arcuate surfaces). -
FIG. 4 is a view illustrating a truing method of a first embodiment. -
FIG. 5 is a view illustrating the truing method of the first embodiment. -
FIG. 6 is a view illustrating a truing method of a second embodiment. -
FIG. 7 is a view illustrating the truing method of the second embodiment. -
FIG. 8 is a view illustrating an example of a method for setting arc boundary positions functioning as boundaries between outer circumference arcuate surfaces and end surface arcuate surfaces. -
FIG. 9 is a view illustrating an example of a truing method in the related art. - Hereinafter, modes for implementing the invention will be described with reference to the drawings. In the figures, in the case where the X-axis, the Y-axis, and the Z-axis are written, the X-axis, the Y-axis, and the Z-axis are perpendicular to one another, a horizontal direction which is parallel to a workpiece rotation axis WJ that is the rotation axis of a workpiece (article to be processed) W is the X-axis direction, a horizontal direction along which a
grindstone 50 is cut into the workpiece W is the Z-axis direction, and a vertical upward direction is the Y-axis direction. - [Entire Configuration (
FIGS. 1(A) and 1(B) ) of aGrinding Machine 1, and Approximate Shapes and Positional Relationships (FIG. 2 ) of Grindstone 50, First Truer 70, and Second Truer 80] - As shown in the plan view of the
grinding machine 1 ofFIG. 1(A) , and the side view of thegrinding machine 1 ofFIG. 1(B) , thegrinding machine 1 which includes the truing apparatus of the invention has abed 2, aheadstock 40, atailstock 46, an X-axis movement table 10, an X-axisdirection driving unit 10M, a Z-axis movement table 20, a Z-axisdirection driving unit 20M, a grindstonerotation driving unit 50M, thegrindstone 50, a controllingunit 60, thefirst truer 70, thesecond truer 80, etc. InFIG. 1(B) , the illustration of thetailstock 46 is omitted. - The
headstock 40 is fixed onto thebed 2, and includes amain spindle 41. - The
main spindle 41 includes achuck 42 which is rotated about the workpiece rotation axis WJ based on a control signal output from the controlling unit 60 (for example, a numerical control apparatus), and which can grip and release the workpiece W. - The
tailstock 46 is fixed onto thebed 2, and includes acenter 47. - The
center 47 is disposed rotatably about the workpiece rotation axis WJ, movable along the direction (X-axis direction) of themain spindle 41, and urged in the direction toward themain spindle 41. - The workpiece W is, for example, a crankshaft for a vehicle, gripped by the
chuck 42 of themain spindle 41, pressed toward themain spindle 41 and supported by thecenter 47, and rotated about the workpiece rotation axis WJ which is parallel to the X-axis, by rotation of themain spindle 41. - The X-axis movement table 10 is reciprocally moved in the X-axis direction with respect to the
bed 2 alongguide rails 10L that are disposed on thebed 2 along the X-axis direction. - The X-axis
direction driving unit 10M (for example, an electric motor) rotates a ball screw which is not shown, based on the control signal output from the controllingunit 60 to reciprocally move the X-axis movement table 10 coupled to the ball screw, in the X-axis direction. The moving distance is controlled based on a detection signal output from anencoder 10E which is disposed in the X-axisdirection driving unit 10M. - The Z-axis movement table 20 is reciprocally moved in the Z-axis direction with respect to the X-axis movement table 10 along
guide rails 20L that are disposed on the X-axis movement table 10 along the Z-axis direction. - The Z-axis
direction driving unit 20M (for example, an electric motor) rotates a ball screw which is not shown, based on the control signal output from the controllingunit 60 to reciprocally move the Z-axis movement table 20 coupled to the ball screw, in the Z-axis direction. The moving distance is controlled based on a detection signal output from anencoder 20E which is disposed in the Z-axisdirection driving unit 20M. - The X-axis
direction driving unit 10M and the Z-axisdirection driving unit 20M correspond to the moving unit which changes the relative position between the grindstone 50 and the workpiece W, that between the grindstone 50 and the first truer 70, and that between the grindstone 50 and the second truer 80. - The grindstone
rotation driving unit 50M (for example, an electric motor) generates a rotating driving force for the grindstone, and the generated rotating driving force is transmitted to thegrindstone 50 through a power transmitting unit such as a pulley and a belt. - The
grindstone 50 is supported rotatably about the grindstone rotation axis XJ which is parallel to the X-axis. Also the grindstone rotation axis XJ is located on a virtual plane VM which is an XZ-plane including the workpiece rotation axis WJ (seeFIG. 1(B) ). - As described above, the controlling
unit 60 receives the detection signals output from theencoders plane VM spindle 41, and the like, and outputs the control signal for rotating themain spindle 41, that for driving the X-axisdirection driving unit 10M, and that for driving the Z-axisdirection driving unit 20M. - The first truer 70 has a
first roll 70D (a diamond roll or the like) which is rotated about a first truer rotation axis TJ1 parallel to the grindstone rotation axis XJ, and aroll driving unit 70M (for example, an electric motor, seeFIG. 2 ) which rotates thefirst roll 70D, and is fixed to, for example, theheadstock 40. - The second truer 80 has a
second roll 80D (a diamond roll or the like) which is rotated about a second truer rotation axis TJ2 perpendicular to the grindstone rotation axis XJ, and aroll driving unit 80M (for example, an electric motor, seeFIG. 2 ) which rotates thesecond roll 80D, and is disposed so as to be movable, for example, alongguide rails 80L in the Z-axis direction with respect to thebed 2. In the case where the workpiece W is supported between themain spindle 41 and thecenter 47, the second truer 80 is moved by the controllingunit 60 in the direction separating from thegrindstone 50 so as not to interfere with the workpiece W, and, in the case where the workpiece W is not supported between themain spindle 41 and thecenter 47, and thegrindstone 50 is to be trued, the second truer 80 is moved by the controllingunit 60 in the direction approaching thegrindstone 50. - As shown in
FIGS. 1(B) and 2, then, the first truer rotation axis TJ1 and the second truer rotation axis TJ2 are located on the virtual plane VM which is an XZ-plane including the workpiece rotation axis WJ. - Therefore, all the workpiece rotation axis WJ, the grindstone rotation axis XJ, the first truer rotation axis TJ1, and the second truer rotation axis TJ2 are on the virtual plane VM (virtual plane which is parallel to the X-axis and the Z-axis), all the workpiece rotation axis WJ, the grindstone rotation axis XJ, and the first truer rotation axis TJ1 are parallel to the X-axis, and the second truer rotation axis TJ2 is parallel to the Z-axis (perpendicular to the X-axis).
- Referring to
FIG. 2 , thegrindstone 50 is configured by agrindstone portion 51 which contains bonding parts and abrasive grains, and which is formed into a cylindrical shape, and a disk-like base portion 52 which holds thegrindstone portion 51. - Then, a place in which the outer circumferential surface of the
grindstone 50, and the virtual plane VM are in contact with each other, and truing is performed by using the first truer 70 is indicated as a to-be-trued place T70, that in which the end surface of thegrindstone 50, and the virtual plane VM are in contact with each other, and truing is performed by using the second truer 80, and which corresponds to the right side inFIG. 2 is indicated as a to-be-trued place T80R, and that in which the end surface of thegrindstone 50, and the virtual plane VM are in contact with each other, and truing is performed by using the second truer 80, and which corresponds to the left side inFIG. 2 is indicated as a to-be-trued place T80L. - At this time, in the case where the rotation direction of the
grindstone 50 is arotation direction 50K shown inFIG. 2 , when the to-be-trued place T70 is to be trued, thefirst roll 70D is rotated in arotation direction 70K; when the to-be-trued place T80R is to be trued, thesecond roll 80D is rotated in a rotation direction 80KR; and, when the to-be-trued place T80L is to be trued, thesecond roll 80D is rotated in a rotation direction 80KL. - When truing is to be performed, therefore, the rotation direction of the
grindstone 50 and that of the first roll are identical to each other, the rotation direction of thegrindstone 50 and that of the second roll are identical to each other, and thegrindstone 50 is trued by the rotation difference. - [Shape (
FIG. 3 ) of Section Including to-be-Trued Places of Grindstone 50] - Next, the shape of a section including the to-be-trued places of the
grindstone 50, and the like will be described with reference toFIG. 3 .FIG. 3 is a sectional view of thegrindstone 50 taken along an XZ-plane including the grindstone rotation axis XJ. - Referring to
FIG. 3 , a surface which is the outer surface (surface which is to be in contact with the workpiece W) of the grindstone 50 (grindstone portion 51), and which is parallel to the grindstone rotation axis XJ is indicated as a grindstone outercircumferential surface 51G. Moreover, a surface which is perpendicular to the grindstone rotation axis XJ, and which is on the right side inFIG. 3 is indicated as a grindstone end surface 51TR, and that which is perpendicular to the grindstone rotation axis XJ, and which is on the left side inFIG. 3 is indicated as a grindstone end surface 51TL. Furthermore, a surface which is a surface at a boundary between the grindstone outercircumferential surface 51G and the grindstone end surface 51TR, and which is formed into an arcuate shape inFIG. 3 is indicated as a grindstone arcuate surface 51ER, and that which is a surface at a boundary between the grindstone outercircumferential surface 51G and the grindstone end surface 51TL, and which is formed into an arcuate shape inFIG. 3 is indicated as a grindstone arcuate surface 51EL. - Moreover, the center of the arc of the grindstone arcuate surface 51ER is indicated as the arc center OR, and that of the arc of the grindstone arcuate surface 51EL is indicated as the arc center OL.
- Then, the boundary position between the grindstone end surface 51TR and the grindstone arcuate surface 51ER is indicated as an end surface boundary position PTR, and that between the grindstone outer
circumferential surface 51G and the grindstone arcuate surface 51ER is indicated as an outer circumferential boundary position PGR. - Similarly, the boundary position between the grindstone end surface 51TL and the grindstone arcuate surface 51EL is indicated as an end surface boundary position PTL, and that between the grindstone outer
circumferential surface 51G and the grindstone arcuate surface 51EL is indicated as an outer circumferential boundary position PGL. - Moreover, a position which, in the grindstone end surface 51TR, is remotest from the grindstone arcuate surface 51ER is indicated as an end surface terminal position PZR.
- Similarly, a position which, in the grindstone end surface 51TL, is remotest from the grindstone arcuate surface 51EL is indicated as an end surface terminal position PZL.
- Referring to
FIG. 3 , then, a point where a first virtual line VTR which has an angle θR (predetermined angle) with respect to the grindstone rotation axis XJ, and which passes through the arc center OR, and the grindstone arcuate surface 51ER intersect with each other is indicated as an arc boundary position PER, and that where a first virtual line VTL which has an angle θL (predetermined angle) with respect to the grindstone rotation axis XJ, and which passes through the arc center OL, and the grindstone arcuate surface 51EL intersect with each other is indicated as an arc boundary position PEL. The angles θR, θL are angles which are adequately set, and, for example, 45 degrees. - Then, a surface which is a partial surface of the grindstone arcuate surface 51ER, which is continuous to the grindstone outer
circumferential surface 51G, and which extends from the outer circumferential boundary position PGR to the arc boundary position PER is indicated as an outer circumference arcuate surface 51FR. Moreover, a surface which is the remaining surface of the grindstone arcuate surface 51ER, which is continuous to the grindstone end surface 51TR, and which extends from the end surface boundary position PTR to the arc boundary position PER is indicated as an end surface arcuate surface 51SR. That is, the grindstone arcuate surface 51ER is divided at the arc boundary position PER into the outer circumference arcuate surface 51FR and the end surface arcuate surface 51SR. - Similarly, a surface which is a partial surface of the grindstone arcuate surface 51EL, which is continuous to the grindstone outer
circumferential surface 51G, and which extends from the outer circumferential boundary position PGL to the arc boundary position PEL is indicated as an outer circumference arcuate surface 51FL. Moreover, a surface which is the remaining surface of the grindstone arcuate surface 51EL, which is continuous to the grindstone end surface 51TL, and which extends from the end surface boundary position PTL to the arc boundary position PEL is indicated as an end surface arcuate surface 51SL. That is, the grindstone arcuate surface 51EL is divided at the arc boundary position PEL into the outer circumference arcuate surface 51FL and the end surface arcuate surface 51SL. - [Truing Method (
FIGS. 4 and 5 ) of First Embodiment] - Next, a truing method of a first embodiment will be described with reference to
FIGS. 4 and 5 . - When truing of the
grindstone 50 is instructed, the controlling unit controls the grindstonerotation driving unit 50M to rotate thegrindstone 50, the first truer 70 to rotate thefirst roll 70D, and the moving unit (the X-axisdirection driving unit 10M, the Z-axisdirection driving unit 20M, and the like) to move the relative position of the first truer 70 with respect to thegrindstone 50, thereby starting truing by the first truer. - When the truing by the first truer 70 is ended, then, the controlling unit controls the second truer 80 to rotate the
second roll 80D, and the moving unit (the X-axisdirection driving unit 10M, the Z-axisdirection driving unit 20M, and the like) to move the relative position of the second truer 80 with respect to thegrindstone 50, thereby starting truing by the second truer. - When the grindstone outer
circumferential surface 51G is to be trued, as shown inFIG. 4 , the controlling unit controls the moving unit to relatively move the first truer 70 with respect to thegrindstone 50 in a state where the first truer rotation axis TJ1 is maintained parallel to the grindstone rotation axis XJ, thereby truing the outer circumference arcuate surface 51FR which is a partial surface of the grindstone arcuate surface 51ER, and which is continuous to the grindstone outercircumferential surface 51G, the grindstone outercircumferential surface 51G, and the outer circumference arcuate surface 51FL which is a partial surface of the grindstone arcuate surface 51EL, and which is continuous to the grindstone outercircumferential surface 51G. - When the grindstone end surface 51TR is to be trued, as shown in
FIG. 5 , the controlling unit controls the moving unit to relatively move the second truer 80 with respect to thegrindstone 50 in a state where the second truer rotation axis TJ2 is maintained in a direction perpendicular to the grindstone rotation axis XJ, thereby truing the end surface arcuate surface 51SR which is the remaining surface of the grindstone arcuate surface 51ER, and which is continuous to the grindstone end surface 51TR, and the grindstone end surface 51TR. - When the grindstone end surface 51TL is to be trued, as shown in
FIG. 5 , the controlling unit controls the moving unit to relatively move the second truer 80 with respect to thegrindstone 50 in a state where the second truer rotation axis TJ2 is maintained in a direction perpendicular to the grindstone rotation axis XJ, thereby truing the end surface arcuate surface 51SL which is the remaining surface of the grindstone arcuate surface 51EL, and which is continuous to the grindstone end surface 51TL, and the grindstone end surface 51TL. - Moreover, the positions and sequence of truing by using the first truer 70 will be described more correctly. As shown in
FIG. 4 , the controlling unit trues the outer circumference arcuate surface 51FR from the arc boundary position PER that is the position which, in the outer circumference arcuate surface 51FR (corresponding to the one outer circumference arcuate surface), is remotest from the grindstone outercircumferential surface 51G, toward the outer circumferential boundary position PGR that is the position which, in the outer circumference arcuate surface 51FR, is closest to the grindstone outercircumferential surface 51G. - Then, the controlling unit trues the grindstone outer
circumferential surface 51G from the outer circumferential boundary position PGR that is the position which, in the grindstone outercircumferential surface 51G, is closest to the outer circumference arcuate surface 51FR, toward the outer circumferential boundary position PGL that is the position which, in the grindstone outercircumferential surface 51G, is closest to the outer circumference arcuate surface 51FL (corresponding to the other outer circumference arcuate surface). - Then, the controlling unit trues the outer circumference arcuate surface 51FL from the outer circumferential boundary position PGL that is the position which, in the outer circumference arcuate surface 51FL, is closest to the grindstone outer
circumferential surface 51G, toward the arc boundary position PEL that is the position which, in the outer circumference arcuate surface 51FL, is remotest from the grindstone outercircumferential surface 51G. - Moreover, the positions and sequence of truing by using the second truer 80 will be described more correctly. As shown in
FIG. 5 , the controlling unit trues the end surface arcuate surface 51SR from the arc boundary position PER that is the position which, in the end surface arcuate surface 51SR (corresponding to the one end surface arcuate surface), is remotest from the grindstone end surface 51TR (corresponding to the one grindstone arcuate surface), toward the end surface boundary position PTR that is the position which, in the end surface arcuate surface 51SR, is closest to the grindstone end surface 51TR. - Then, the controlling unit trues the grindstone end surface 51TR from the end surface boundary position PTR that is the position which, in the grindstone end surface 51TR, is closest to the end surface arcuate surface 51SR, toward the end surface terminal position PZR that is the position which, in the grindstone end surface 51TR, is remotest from the end surface arcuate surface 51SR.
- As shown in
FIG. 5 , similarly, the controlling unit trues the end surface arcuate surface 51SL from the arc boundary position PEL that is the position which, in the end surface arcuate surface 51SL (corresponding to the other end surface arcuate surface), is remotest from the grindstone end surface 51TL (corresponding to the other grindstone end surface), toward the end surface boundary position PTL that is the position which, in the end surface arcuate surface 51SL, is closest to the grindstone end surface 51TL. - Then, the controlling unit trues the grindstone end surface 51TL from the end surface boundary position PTL that is the position which, in the grindstone end surface 51TL, is closest to the end surface arcuate surface 51SL, toward the end surface terminal position PZL that is the position which, in the grindstone end surface 51TL, is remotest from the end surface arcuate surface 51SL.
- At the start of the truing of the outer circumference arcuate surface 51FR, as shown in
FIG. 4 , when, in the case where the first truer 70 is made relatively close to thegrindstone 50 toward the arc boundary position PER, the first truer is relatively moved from the side of the end surface arcuate surface 51SR so as to be moved along a first virtual arc VE1 which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface 51ER, which is in contact with the grindstone arcuate surface 51ER at the arc boundary position PER, and which has a first diameter, the truing from the arc boundary position PER can be started more smoothly. Therefore, this is more preferable. The value of the first diameter is appropriately set. - At the end of the truing of the outer circumference arcuate surface 51FL, when, in the case where the first truer 70 is relatively separated from the arc boundary position PEL with respect to the
grindstone 50, the first truer is relatively moved to the side of the end surface arcuate surface 51SL so as to be moved along a fourth virtual arc VEZ which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface 51EL, which is in contact with the grindstone arcuate surface 51EL at the arc boundary position PEL, and which has a fourth diameter, the truing in the arc boundary position PEL can be ended more smoothly. Therefore, this is more preferable. The value of the fourth diameter is appropriately set. - At the start of the truing of the end surface arcuate surface 51SR, as shown in
FIG. 5 , when, in the case where the second truer 80 is made relatively close to thegrindstone 50 toward the arc boundary position PER, the second truer is relatively moved from the side of the outer circumference arcuate surface 51FR so as to be moved along a second virtual arc VE2 which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface 51ER, which is in contact with the grindstone arcuate surface 51ER at the arc boundary position PER, and which has a second diameter, the truing from the arc boundary position PER can be started more smoothly. Therefore, this is more preferable. The value of the second diameter is appropriately set. - At the start of the truing of the end surface arcuate surface 51SL, as shown in
FIG. 5 , when, in the case where the second truer 80 is made relatively close to thegrindstone 50 toward the arc boundary position PEL, the second truer is relatively moved from the side of the outer circumference arcuate surface 51FL so as to be moved along a third virtual arc VE3 which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface 51EL, which is in contact with the grindstone arcuate surface 51EL at the arc boundary position PEL, and which has a third diameter, the truing from the arc boundary position PEL can be started more smoothly. Therefore, this is more preferable. The value of the third diameter is appropriately set. - [Truing Method (
FIGS. 6 and 7 ) of Second Embodiment] - Next, a truing method of a second embodiment will be described with reference to
FIGS. 6 and 7 . - The truing method of the second embodiment shown in
FIG. 6 is different from that of the first embodiment shown inFIG. 4 in that the path in the case where the first truer 70 is made close to the arc boundary position PER, and that in the case where the first truer is separated from the arc boundary position PEL are not paths which extend along the virtual arcs, but those which extend along virtual lines parallel to the grindstone rotation axis XJ. - The truing method of the second embodiment shown in
FIG. 7 is different from that of the first embodiment shown inFIG. 5 in that the path in the case where the second truer 70 is made close to the arc boundary position PER, and that in the case where the second truer is made close to the arc boundary position PEL are not paths which extend along the virtual arcs, but those which extend along virtual lines perpendicular to the grindstone rotation axis XJ. - Hereinafter, description will be made with emphasis on these different points.
- At the start of the truing of the outer circumference arcuate surface 51FR, as shown in
FIG. 6 , when, in the case where the first truer 70 is made relatively close to thegrindstone 50 toward the arc boundary position PER, the first truer 70 is relatively moved with respect to thegrindstone 50 so as to be moved along a virtual line VTA which is parallel to the grindstone rotation axis XJ, and which passes through the arc boundary position PER. According to the configuration, the first truer 70 can be made relatively close to thegrindstone 50 through the simple path. - At the end of the truing of the outer circumference arcuate surface 51FL, as shown in
FIG. 6 , when, in the case where the first truer 70 is relatively separated from the grindstone 50 from the arc boundary position PEL, the first truer 70 is relatively moved with respect to thegrindstone 50 so as to be moved along a virtual line VTB which is parallel to the grindstone rotation axis XJ, and which passes through the arc boundary position PEL. According to the configuration, the first truer 70 can be relatively separated from thegrindstone 50 through the simple path. - At the start of the truing of the end surface arcuate surface 51SR, as shown in
FIG. 7 , when, in the case where the second truer 80 is made relatively close to thegrindstone 50 toward the arc boundary position PER, the second truer 80 is relatively moved with respect to thegrindstone 50 so as to be moved along a virtual line VTC which is perpendicular to the grindstone rotation axis XJ, and which passes through the arc boundary position PER. According to the configuration, the second truer 80 can be made relatively close to thegrindstone 50 through the simple path. - At the start of the truing of the end surface arcuate surface 51SL, as shown in
FIG. 7 , when, in the case where the second truer 80 is made relatively close to thegrindstone 50 toward the arc boundary position PEL, the second truer 80 is relatively moved with respect to thegrindstone 50 so as to be moved along a virtual line VTD which is perpendicular to the grindstone rotation axis XJ, and which passes through the arc boundary position PEL. According to the configuration, the second truer 80 can be made relatively close to thegrindstone 50 through the simple path. - [Example (
FIG. 8 ) of Method for Setting Boundary Positions (Arc Boundary Positions PER, PEL) Between Outer Circumference Arcuate Surface and End Surface Arcuate Surfaces] - In the description of
FIG. 3 , the angles θR, θL (predetermined angles) of the first virtual lines VTR, VTL with respect to the grindstone rotation axis XJ in the case where the arc boundary positions PER, PEL are to be set are, for example, 45 degrees. However, the below-described setting of angles θR′, θL′ (predetermined angles) shown inFIG. 8 is more preferable. - In the shape of the grindstone 50 (grindstone portion 51) after truing of the grindstone 50 (grindstone portion 51) before truing, as shown in
FIG. 8 , the truing depth (machining allowance due to truing) in a direction perpendicular to the grindstone rotation axis XJ is set as ΔD, and the truing depth (machining allowance due to truing) in the direction parallel to the grindstone rotation axis XJ is set as ΔW. - As shown in
FIG. 8 , then, the center of the arc of the right grindstone arcuate surface before truing is indicated as the arc center OR, and that of the arc of the left grindstone arcuate surface before truing is indicated as the arc center OL. - Then, a position which is further moved by ΔW in the direction separating from the right grindstone end surface, from a position that is moved by ΔD from the position of the arc center OR in the direction separating from the grindstone outer circumferential surface is set as a new arc center OR′ which is the center of the arc of the right grindstone arcuate surface after truing.
- Then, the intersection of a second virtual line VTR2 which passes through the arc center OR and the arc center OR′, and the right grindstone arcuate surface before truing is set as the arc boundary position PER before truing, and that of the second virtual line VTR2 and the right grindstone arcuate surface after truing is set as the arc boundary position PER′ after truing.
- From the above, an angle θR′ of the second virtual line VTR2 with respect to the grindstone rotation axis XJ is given by the following expression:
-
Angle θR′=tan−1(ΔD/ΔW). - Similarly, a position which is further moved by ΔW in the direction separating from the left grindstone end surface, from a position that is moved by ΔD from the position of the arc center OL in the direction separating from the grindstone outer circumferential surface is set as a new arc center OL′ which is the center of the arc of the left grindstone arcuate surface after truing.
- Then, the intersection of a second virtual line VTL2 which passes through the arc center OL and the arc center OL′, and the right grindstone arcuate surface before truing is set as the arc boundary position PEL before truing, and that of the second virtual line VTL2 and the right grindstone arcuate surface after truing is set as the arc boundary position PEL′ after truing.
- An angle θL′ is identical with the angle θR′, and therefore its description is omitted.
- Although, in the above description of the embodiments, the truing methods for truing the grindstone by using the first truer and the second truer have been described, it is possible to realize a truing apparatus including: a first truer having a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis XJ; a second truer having a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis XJ; a moving unit; and a controlling unit, the apparatus truing the grindstone outer circumferential surface, grindstone end surfaces, and grindstone arcuate surfaces of the grindstone, based on the truing methods which have been described in the embodiments.
- In the truing methods which have been described in the embodiments, the grindstone end surfaces, and the grindstone arcuate surfaces (end surface arcuate surface) which are continuous to the grindstone end surfaces can be adequately trued, the fracturability of the abrasive grains is improved, and the sharpness of the grindstone is improved. The improvement of the sharpness can adequately prevent grinding burn from occurring, and contribute to cost reduction.
- Moreover, truing is performed in appropriate sequence and route. Therefore, truing can be performed in a shorter period of time, and this can contribute to shortening of the process time and energy saving.
- Furthermore, the invention can cope with processing which is applied to, for example, a crankshaft for a special vehicle, and in which accuracies of grindstone end surfaces are required, reduce the friction resistance of the crankshaft, and contribute to improvement of fuel efficiency of the vehicle.
- In the truing method of the invention, various changes, additions, and deletions may be made without changing the spirit of the invention. The configuration, structure, shape, and the like of the truing apparatus of the invention may be variously modified, added, or deleted without changing the spirit of the invention.
- Moreover, the configuration, structure, shape, and the like of the grinding
machine 1 which have been described in the embodiments may be variously modified, added, or deleted without changing the spirit of the invention. - The application is based on Japanese Patent Application (No. 2013-215492) filed Oct. 16, 2013, and its disclosure is incorporated herein by reference.
- According to the invention, it is possible to adequately process an article to be processed in which the accuracies of grindstone end surfaces, and those of grindstone arcuate surfaces in the vicinity of the grindstone end surfaces are required.
-
- 1 grinding machine
- 2 bed
- 10 X-axis movement table
- 10M X-axis direction driving unit
- 20 Z-axis movement table
- 20M Z-axis direction driving unit
- 40 headstock
- 41 main spindle
- 46 tailstock
- 47 center
- 50 grindstone
- 51 grindstone portion
- 51ER, 51EL grindstone arcuate surface
- 51FR, 51FL outer circumference arcuate surface
- 51G grindstone outer circumferential surface
- 51SR, 51SL end surface arcuate surface
- 51TR, 51TL grindstone end surface
- 60 controlling unit
- 70 first truer
- 70D first roll
- 80 second truer
- 80D second roll
- OR, OL arc center
- PER, PEL arc boundary position
- PGR, PGL outer circumferential boundary position
- PTR, PTL end surface boundary position
- PZR, PZL end surface terminal position
- TJ1 first truer rotation axis
- TJ2 second truer rotation axis
- VE1 first virtual arc
- VE2 second virtual arc
- VE3 third virtual arc
- VM virtual plane
- VTR, VTL first virtual line
- VTR2, VTL2 second virtual line
- W workpiece
- WJ workpiece rotation axis
- XJ grindstone rotation axis
Claims (6)
1: A truing method which performs truing by using:
first and second truers which true a cylindrical grindstone that is rotated about a grindstone rotation axis to grind a workpiece;
a moving unit which is configured to change a relative position between the first truer and the grindstone, and a relative position between the second truer and the grindstone; and
a controlling unit which is configured to control the moving unit, wherein
the first truer has a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis,
the second truer has a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis,
the grindstone has: a grindstone outer circumferential surface which is a surface that is parallel to the grindstone rotation axis; grindstone end surfaces which are surfaces that are perpendicular to the grindstone rotation axis; and grindstone arcuate surfaces which are surfaces in boundaries between the grindstone outer circumferential surface and the grindstone end surfaces, and which are formed into an arcuate shape, the truing method comprising:
controlling the moving unit by the controlling means unit, in a state where the first truer rotation axis is maintained parallel to the grindstone rotation axis, to true, by using the first truer, the grindstone outer circumferential surface, and outer circumference arcuate surfaces which are partial surfaces of the grindstone arcuate surfaces and which are continuous to the grindstone outer circumferential surface; and
controlling the moving unit by the controlling unit, in a state where the second truer rotation axis is maintained in a direction perpendicular to the grindstone rotation axis, to true, by using the second truer, the grindstone end surfaces, and end surface arcuate surfaces which are remaining surfaces of the grindstone arcuate surfaces and which are continuous to the grindstone end surfaces.
2: The truing method according to claim 1 , wherein,
when truing is performed by using the first truer,
one of the outer circumference arcuate surfaces is trued from a position remotest from the grindstone outer circumferential surface in the one outer circumference arcuate surface, toward a position closest to the grindstone outer circumferential surface in the one outer circumference arcuate surface, the grindstone outer circumferential surface is then trued from a position closest to the one outer circumference arcuate surface in the grindstone outer circumferential surface, toward a position closest to the other outer circumference arcuate surface in the grindstone outer circumferential surface, and the other outer circumference arcuate surface is then trued from a position closest to the grindstone outer circumferential surface in the other outer circumference arcuate surface, toward a position remotest from the grindstone outer circumferential surface in the other outer circumference arcuate surface,
when truing is performed by using the second truer,
one of the end surface arcuate surfaces is trued from a position remotest from one of the grindstone end surfaces in the one end surface arcuate surface, toward a position closest to the one grindstone end surface in the one end surface arcuate surface, and the one grindstone end surface is then trued from a position closest to the one end surface arcuate surface in the one grindstone end surface, toward a position remotest from the one end surface arcuate surface in the one grindstone end surface, and
the other end surface arcuate surface is trued from a position remotest from the other grindstone end surface in the other end surface arcuate surface, toward a position closest to the other grindstone end surface in the other end surface arcuate surface, and the other grindstone end surface is then turned from a position closest to the other end surface arcuate surface in the other grindstone end surface, toward a position remotest from the other end surface arcuate surface in the other grindstone end surface.
3: The truing method according to claim 2 , wherein,
at a start of truing of the one outer circumference arcuate surface, when the first truer is made relatively close to the grindstone toward the position remotest from the grindstone outer circumferential surface in the one outer circumference arcuate surface, the first truer is relatively moved from a side of the one end surface arcuate surface so as to be moved along a first virtual arc which is a virtual arc having a convex direction that is opposite to a convex direction of the grindstone arcuate surface, the first virtual arc being in contact with the grindstone arcuate surface at a boundary position between the one outer circumference arcuate surface and the one end surface arcuate surface, the first virtual arc having a first diameter,
at a start of truing of the one end surface arcuate surface, when the second truer is made relatively close to the grindstone toward the position remotest from the grindstone end surface in the one end surface arcuate surface, the second truer is relatively moved from a side of the one outer circumference arcuate surface so as to be moved along a second virtual arc which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface, the second virtual arc being in contact with the grindstone arcuate surface at the boundary position between the one outer circumference arcuate surface and the one end surface arcuate surface, the second virtual arc having a second diameter, and,
at a start of truing of the other end surface arcuate surface, when the second truer is made relatively close to the grindstone toward the position remotest from the grindstone end surface in the other end surface arcuate surface, the second truer is relatively moved from a side of the other outer circumference arcuate surface so as to be moved along a third virtual arc which is a virtual arc having a convex direction that is opposite to the convex direction of the grindstone arcuate surface, the third virtual arc being in contact with the grindstone arcuate surface at a boundary position between the other outer circumference arcuate surface and the other end surface arcuate surface, the third virtual arc having a third diameter.
4: The truing method according to claim 1 , wherein
the boundary position which is between the outer circumference arcuate surface and the end surface arcuate surface in the grindstone arcuate surface is a position where a first virtual line that passes through a center of an arc of the grindstone arcuate surface before truing and that has an angle of 45 degrees with respect to the grindstone rotation axis, intersects with the grindstone arcuate surface.
5: The truing method according to claim 1 , wherein
the boundary position which is between the outer circumference arcuate surface and the end surface arcuate surface in the grindstone arcuate surface is a position where,
in a case where a depth by which the grindstone outer circumferential surface is to be trued is indicated as ΔD, and a depth by which the grindstone end surface is to be trued is indicated as ΔW,
a second virtual line intersects with the grindstone arcuate surface, the second virtual line that passes through a center of an arc of the grindstone arcuate surface before truing, and a center of the arc after truing which is a position that is further separated by ΔW in a direction separating from the grindstone end surface from a position that is moved from the center of the arc before truing by ΔD in a direction separating from the grindstone outer circumferential surface.
6: A truing apparatus comprising:
a first truer which is disposed for truing a cylindrical grindstone that is rotated about a grindstone rotation axis to grind a workpiece, and which has a first roll which is rotated about a first truer rotation axis that is parallel to the grindstone rotation axis;
a second truer which is disposed for truing the grindstone, and which has a second roll which is rotated about a second truer rotation axis that is perpendicular to the grindstone rotation axis;
a moving unit which is configured to change a relative position between the first truer and the grindstone, and a relative position between the second truer and the grindstone; and
a controlling unit which is configured to control the moving unit, wherein,
by using the moving unit and the controlling unit, based on the truing method according to claim 1 , the truing apparatus trues the grindstone outer circumferential surface, the grindstone end surfaces, and the grindstone arcuate surfaces of the grindstone.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013215492A JP6197567B2 (en) | 2013-10-16 | 2013-10-16 | Truing method and truing device |
JP2013-215492 | 2013-10-16 | ||
PCT/JP2014/077573 WO2015056746A1 (en) | 2013-10-16 | 2014-10-16 | Truing method and truing device |
Publications (1)
Publication Number | Publication Date |
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US20160236321A1 true US20160236321A1 (en) | 2016-08-18 |
Family
ID=52828187
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US15/029,931 Abandoned US20160236321A1 (en) | 2013-10-16 | 2014-10-16 | Truing method and truing device |
Country Status (5)
Country | Link |
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US (1) | US20160236321A1 (en) |
JP (1) | JP6197567B2 (en) |
CN (1) | CN105636744B (en) |
DE (1) | DE112014004767T5 (en) |
WO (1) | WO2015056746A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US20170165806A1 (en) * | 2015-12-14 | 2017-06-15 | Jtekt Corporation | Truer, truing apparatus including truer, grinder, and truing method |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6717106B2 (en) * | 2016-08-08 | 2020-07-01 | 株式会社ジェイテクト | Truing device and truing method |
DE102018130908A1 (en) * | 2018-12-05 | 2020-06-10 | Schaeffler Technologies AG & Co. KG | Dressing device and method for dressing a grinding tool |
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-
2013
- 2013-10-16 JP JP2013215492A patent/JP6197567B2/en active Active
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2014
- 2014-10-16 DE DE112014004767.8T patent/DE112014004767T5/en active Pending
- 2014-10-16 CN CN201480057263.4A patent/CN105636744B/en active Active
- 2014-10-16 WO PCT/JP2014/077573 patent/WO2015056746A1/en active Application Filing
- 2014-10-16 US US15/029,931 patent/US20160236321A1/en not_active Abandoned
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US2778353A (en) * | 1954-01-05 | 1957-01-22 | Gleason Works | Wheel dresser |
US3398253A (en) * | 1965-10-19 | 1968-08-20 | F Jos Lamb Company Inc | Grinding machine with electric discharge machining mechanism for reshaping crush roll |
US3747584A (en) * | 1972-01-24 | 1973-07-24 | Toyoda Machine Works Ltd | Rotary dressing apparatus |
US5551908A (en) * | 1993-04-26 | 1996-09-03 | Fuji Oozx, Inc. | Centerless grinder and wheel truing device therefor |
US6783428B1 (en) * | 1999-01-18 | 2004-08-31 | Nsk Ltd. | Method for forming grooves on workpiece and for dressing a grindstone used in the groove formation |
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Cited By (2)
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US20170165806A1 (en) * | 2015-12-14 | 2017-06-15 | Jtekt Corporation | Truer, truing apparatus including truer, grinder, and truing method |
US10099342B2 (en) * | 2015-12-14 | 2018-10-16 | Jtekt Corporation | Truer, truing apparatus including truer, grinder, and truing method |
Also Published As
Publication number | Publication date |
---|---|
JP6197567B2 (en) | 2017-09-20 |
JP2015077650A (en) | 2015-04-23 |
CN105636744B (en) | 2018-01-12 |
DE112014004767T5 (en) | 2016-08-11 |
WO2015056746A1 (en) | 2015-04-23 |
CN105636744A (en) | 2016-06-01 |
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