JP2013154462A - Truing device of grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a truing device of a grinding machine, allowing truing at higher precision.SOLUTION: A truing device of a grinding machine 1 includes: a truer 31 forming the shape of a grinding wheel 11; a detection means 33 detecting a relative axial position of a truer 31 with respect to the grinding wheel 11 by bringing the truer 31 into contact with the end face in the axial direction of the grinding wheel 11 in a rotating state of the grinding wheel 11; and a control means 40 for performing the truing by controlling the relative movement of the truer 31 with respect to the grinding wheel 11 on the basis of the detected relative axial position of the truer 31.

Description

  The present invention relates to a truing apparatus including a truer for shaping the shape of a grinding wheel in a grinding machine for grinding a workpiece with a grinding wheel.

  Some grinding machines include a truing device that forms a grinding surface of a grinding wheel with a truer in order to process a workpiece into a predetermined shape or to maintain the processing efficiency of the grinding process suitably. As such a truing device, for example, Patent Document 1 discloses a device that performs truing by moving a rotatable rotary tool (generally also referred to as “rotary dresser”) relative to a grinding wheel. ing. By the way, in the grinding machine, the relative position of the grinding wheel and the truer may change due to wear or thermal displacement of each part including the grinding wheel and the rotary truer. Therefore, when the truer is positioned at a control position such as a start reference position in truing, a positioning error may occur with respect to the control position.

  In order to improve the accuracy of truing, it is necessary for the truing device of the grinding machine to reduce the influence of the positioning error of the truer. Therefore, a method for correcting the truing start reference position based on the contact position by detecting the contact between the grinding wheel and the truer is known. For example, Patent Document 1 discloses a method for detecting contact using a displacement of a rotary shaft of a rotary truer when a grinding wheel and a rotary truer come into contact with each other. Further, for example, Patent Document 2 discloses a method for grasping the position of the rotary truer with respect to the grinding wheel based on the contact between the contact detection roll and the grinding wheel supported coaxially with the rotary truer. According to such a truing device, it is possible to correct the true truing start reference position of the truer with respect to the grinding wheel by correcting the movement amount of the truer based on the positional relationship between the grinding wheel and the truer detected in contact. ing.

JP 2007-260809 A Japanese Patent Laid-Open No. 2007-083351

  Here, in the drive state of the grinding machine, as described above, thermal displacement occurs in each part of the grinding machine. Similarly, in a truing apparatus including a rotary truer, thermal displacement is caused by heat generated by an electric motor that rotationally drives the rotary truer or a bearing that supports the rotary shaft of the rotary truer. Such thermal displacement of the grinding machine includes axial thermal displacement of each rotating shaft. Conventionally, thermal displacement in the axial direction in a truing device may not be affected depending on the shape of the grinding wheel to be molded, and even if it is affected, it has been dealt with by securing a certain amount of truer cutting to the grinding wheel. It was. This is because the axial thermal displacement is due to the fact that the amount of displacement is small compared to the radial thermal displacement, and that the rotary truer is accompanied by thermal deformation of the rotary shaft that requires rotational driving only during truing. It is done. However, the shape of the grinding wheel becomes complicated, and in order to meet the demands for higher speed of truing and higher accuracy of truing, the effect of thermal displacement becomes significant, so correct appropriately Has come to be required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a truing device for a grinding machine that enables truing with higher accuracy.

  In order to solve the above-mentioned problem, according to the invention according to claim 1, in the state where the grinding wheel is shaped and the grinding wheel is rotated, the end surfaces in the axial direction of the grinding wheel and the grinding wheel are And detecting means for detecting a relative axial direction position of the truer with respect to the grinding wheel, and controlling the relative movement of the truer with respect to the grinding wheel based on the detected relative axial direction position of the truer. And a control means for performing.

  According to the second aspect of the present invention, the truer is a rotary truer that is rotatably supported, and the detecting means rotates both the grinding wheel and the rotary truer, and the rotation shafts of the two members are rotated. In a state where they are maintained in parallel, the end faces of the two members facing each other in the axial direction are brought into contact with each other to detect the relative axial position.

  According to the third aspect of the present invention, the detection means brings the end surface of the core portion of the grinding wheel facing in the axial direction into contact with the end surface of the core portion of the rotary truer, and the relative axial direction position of the rotary truer Is detected.

According to the invention which concerns on Claim 4, the core part of one member among the said grinding wheel and the said rotary truer is extended in an axial direction from the end surface of the disk-shaped core main body and the said core main body, and is from the outer diameter of the said core main body. A columnar portion having a small outer diameter, and the detection means contacts the tip surface of the columnar portion with the end surface of the other member of the grinding wheel and the rotary truer, The relative axial position is detected.
According to the invention which concerns on Claim 5, the outer peripheral surface of the said grinding wheel is formed in a non-cylindrical shape in the case of truing by the said control means.

  According to the first aspect of the present invention, the truing device performs truing by controlling based on the relative axial direction position of the truer with respect to the grinding wheel detected by the detecting means. The relative axial position of the truer by this detecting means is detected by bringing the end face of the rotating grinding wheel in the axial direction into contact with the end face of the truer. Thereby, the relative axial direction position of the truer with respect to the grinding wheel can be detected more accurately in consideration of the axial thermal displacement of the grinding wheel. And a control means controls the relative position of a truer and a grinding wheel based on the detected relative axial direction position, and can set more correctly the truing start reference position used as a reference position in truing. Therefore, the truing device can reduce the influence of thermal displacement associated with the speeding up of the rotational speed required for grinding or truing, and can perform truing with higher accuracy. Thereby, the removal amount of the grinding wheel in truing can be suppressed to the minimum, and the life of the grinding wheel can be prolonged. And by using such a grinding wheel for grinding, grinding can be performed with higher accuracy. The “truer” in the present invention includes an abrasive grain layer and a core part in the case of a rotary truer, and includes a cutting edge part, a truer body, and a holder part in the case of a fixed type truer. Similarly, the “grinding wheel” in the present invention includes an abrasive layer and a core portion.

  Further, since the contact between the grinding wheel and the truer is detected by the detection means, a contact signal is more suitably generated by the rotation of the grinding wheel, and the detection sensitivity of the detection means can be improved. Thereby, since the contact time of a grinding wheel and a truer can be shortened, the abrasion by contact can be reduced.

  According to the second aspect of the present invention, the truer is a rotary truer that is rotatably supported, and the relative axial direction position of the rotary truer is a grinding wheel and a rotary truer whose rotational axes are maintained in parallel by the detecting means. This is detected by bringing the end faces of the two into contact with each other. Accordingly, it is possible to more accurately detect the truing start reference position of the rotary truer relative to the grinding wheel by further taking into account the axial thermal displacement of the rotary truer due to the thermal deformation of the rotary shaft of the rotary truer.

  Moreover, in this invention, when detecting the relative axial direction position of a grinding wheel and a rotary truer, it is set as the state which rotated both members. Thereby, it becomes the same as the state where the thermal displacement has occurred in the actual truing, and the truing start reference position in consideration of the thermal displacement amount in the truing can be detected. Furthermore, since the contact between the grinding wheel and the rotary truer is detected by the detection means, a contact signal is more suitably generated by rotating both members, and the detection sensitivity of the detection means can be further improved.

  According to the invention which concerns on Claim 3, a detection means makes the core parts of a grinding wheel and a rotary truer contact, and detects the relative axial direction position of the rotary truer with respect to a grinding wheel. The core portion is not a part that is worn by grinding and truing, and is displaced in the axial direction along with the thermal deformation of the rotating shaft. Therefore, the detection means can prevent the influence of wear or the like by bringing the end faces of the core portions of the opposing members into contact with each other, and can grasp the relationship between the axial positions of the two members with higher accuracy. Therefore, the truing device can perform truing with higher accuracy.

  According to the invention which concerns on Claim 4, it is set as the structure which provides a columnar part in at least one of the end surface of the core part of a grinding wheel, or the end surface of the core part of a rotary truer. Thus, when detecting the relative axial direction position and the relative radial direction position of the grinding wheel and the rotary truer, the protruding portion such as a bolt existing on the end surface of the core part of the grinding wheel or the rotary truer is It can prevent contacting with an abrasive grain layer, the end surface of the outer peripheral surface of a core part, the other protrusion part of a core part, etc. Accordingly, it is possible to prevent abrasion of the abrasive grain layer of the grinding wheel or the rotary truer, abrasion of the core portion of the grinding wheel or the core portion of the rotary truer, breakage of the protruding portion protruding from the core portion, and the like.

  According to the invention which concerns on Claim 5, the outer peripheral surface of a grinding wheel is shape | molded by the non-cylindrical shape in the case of truing by a control means. Here, in the truing device provided with the rotary shaft of the grinding wheel and the rotary truer, the rotary shaft of the rotary truer is affected by the heat generated by the driving device, the bearing, etc., and supports the grinding wheel or rotary truer to be supported in the axial direction. Displace to. When such a thermal displacement occurs, if the shape of the grinding wheel to be molded is non-cylindrical, that is, tapered or has at least a part formed in an arc shape, truing due to thermal displacement The impact on will be greater. In particular, in the case of an all-round rotary truer that transfers the outer peripheral surface shape of the rotary truer to a grinding wheel, this effect becomes significant.

  Conventionally, in order to allow the thermal displacement of the rotary truer, it has been dealt with by setting the cutting depth deep so as to increase the grinding amount (removal amount) of the grinding wheel in truing. On the other hand, according to the present invention, truing with higher accuracy is possible, so that the removal amount of the grinding wheel in truing can be suppressed to a minimum. Therefore, it is possible to extend the life of the grinding wheel used for grinding.

It is a top view of a grinding machine provided with a truing device in an embodiment. It is a top view which shows the detection state of the axial direction position of the grinding wheel and rotary truer by a sensor unit. It is a top view which shows the detection state of the radial direction position of the grinding wheel and rotary truer by a sensor unit. It is a top view which shows the state which is truing a grinding wheel. It is a flowchart which shows the process of truing.

<Embodiment>
(Configuration of grinding machine truing device)
The grinding machine 1 of this embodiment is demonstrated with reference to FIGS. 1-3. The grinding machine 1 is a machine tool that performs grinding by moving the grinding wheel 11 relative to the workpiece W supported by the bed 2. The grinding machine 1 includes a grinding wheel base 10, a workpiece support device 20, a truing device 30, and a control device 40 (corresponding to "control means" of the present invention).

  The grinding wheel base 10 has a grinding wheel 11 and a grinding wheel shaft 12. The grinding wheel platform 10 is provided with a driving device (not shown) that rotationally drives a grinding wheel 11 that grinds the workpiece W. The grinding wheel shaft 12 is a rotating shaft of the grinding wheel 11 that is rotatably supported by the grinding wheel base 10 via a bearing and is rotationally driven at a predetermined rotational speed by the driving device. The grinding wheel 11 includes a core part 111 and an abrasive grain layer 112. In the present embodiment, the core portion 111 is a metal core such as iron formed in a disk shape, and is detachably connected to the grindstone shaft 12 with a bolt or the like. The abrasive grain layer 112 is a part that comes into contact with the workpiece W during the grinding process, and is configured, for example, by bonding super hard CBN abrasive grains to the outer periphery of the core part 111 by vitrified bond or the like.

  The grinding wheel base 10 is guided and supported on a guide rail (not shown) that is disposed on the upper surface of the bed 2 and extends in a direction orthogonal to the central axis Aw of the grinding wheel 11. Thereby, the grinding wheel 11 is movable in the Z-axis direction (vertical direction in FIG. 1) that is parallel to the upper surface of the bed 2 and is the radial direction of the workpiece W. Further, the grinding wheel platform 10 is controlled by the control device 40 to move the grinding wheel 11 in the Z-axis direction, the number of rotations, and the like.

  The workpiece support device 20 supports both ends of the workpiece W so as to be rotatable around the central axis of the workpiece W. The workpiece support device 20 includes a table 21, a spindle stock 22, a tailstock 23, a chuck 24, and a center 25. The table 21 is guided and supported on a guide rail (not shown) that is disposed on the upper surface of the bed 2 of the grinding machine 1 and extends in the direction of the central axis Aw of the grinding wheel 11. Thereby, the table 21 is movable in the X-axis direction (left-right direction in FIG. 1) that is parallel to the upper surface of the bed 2 and that is the axial direction of the workpiece W.

  The headstock 22 and the tailstock 23 are arranged to face the upper surface of the table 21 and support one end or the other end of the workpiece W, respectively. The spindle stock 22 is provided with a spindle that is rotated by a drive device (not shown), and is configured such that the workpiece W rotates when the spindle is driven to rotate. Further, the spindle stock 22 is controlled by the control device 40 in terms of the rotational speed and rotational phase of the spindle. The headstock 22 is provided with a chuck 24 for gripping one end of the workpiece W, and the tailstock 23 is provided with a center 25 for supporting the other end of the workpiece W. Therefore, both ends of the workpiece W are supported by the chuck 24 and the center 25 so as to be rotatable about an axis parallel to the moving direction (X-axis direction) of the table 21, and are rotated by the headstock 22.

  The truing device 30 is a device that is fixed to the side surface of the headstock 22 on the side of the grinding wheel 10 and trues the outer peripheral surface of the grinding wheel 11. The truing device 30 includes a rotary truer 31, a truer shaft 32, and an AE sensor 33 (corresponding to “detecting means” of the present invention). The truing device 30 is provided with a built-in motor (not shown) that rotationally drives the rotary truer 31. The rotary truer 31 is a truing tool for forming the shape of the grinding wheel 11 and is composed of a core portion 311 and an abrasive grain layer 312. For example, a granular diamond is sintered on the outer periphery of the core portion 311 to form an abrasive grain layer. 312 is formed. The truer shaft 32 is a rotating shaft of the rotary truer 31 that is rotatably supported by the truing device 30 via a bearing and is driven to rotate at a predetermined rotational speed by the built-in motor.

  The core portion 311 includes a disk-shaped core body 311a and a columnar detection portion 311b (corresponding to the “columnar portion” of the present invention). In the present embodiment, the core body 311a is a metal core such as iron and is detachably connected to the truer shaft 32 with a bolt or the like. Thereby, the rotary truer 31 can rotate around the central axis At. Further, the detection unit 311 b of the core unit 311 is formed in a columnar shape extending in the direction of the central axis At of the rotary truer 31. The detection unit 311b is formed integrally with the core body 311a and is a part that contacts the core unit 111 of the grinding wheel 11 when detecting the relative axial position of the grinding wheel 11 and the rotary truer 31. And the outer diameter Dp of the detection part 311b is formed so that it may become smaller than the outer diameter Dc of the core main body 311a, as shown in FIG. The core portion 311 having the detecting portion 311b functioning as a contact is thus preferably formed of hardened steel or the like in order to reduce the amount of wear when contacting the grinding wheel 11.

  The AE sensor 33 is housed in the cylinder of the truer shaft 32, detects an AE (Acoustic Emission) wave generated by the contact between the detection unit 311b and the grinding wheel 11 that is the object of contact detection, and controls the contact signal. 40 is a detection means for outputting to 40.

  Further, the AE sensor 33 is in a state in which both the members 11 and 31 of the grinding wheel 11 and the rotary truer 31 are rotated and the rotary shafts (that is, the grindstone shaft 12 and the truer shaft 32) are maintained in parallel. The relative axial direction position of the rotary truer 31 relative to the grinding wheel 11 is detected by bringing the end face of the core portion 111 of the grinding wheel 11 facing the axial direction into contact with the end face of the detection portion 311b of the core portion 311 of the rotary truer 31. Further, as shown in FIG. 3, the AE sensor 33 detects the relative radial position of the rotary truer 31 with respect to the grinding wheel 11 by bringing the outer circumferential surface of the grinding wheel 11 into contact with the outer circumferential surface of the detection unit 311 b. . Details of position detection of the grinding wheel 11 and the rotary truer 31 using the AE sensor 33 will be described later.

  The truing device 30 having such a configuration first moves the rotary truer 31 in the X-axis direction by moving the table 21 when performing truing. Then, the tip position of the rotary truer 31 relative to the grinding wheel 11 is positioned at the truing start reference position by the movement of the grinding wheel 11 in the Z-axis direction by the grinding wheel base 10. Subsequently, truing can be performed by synchronizing the grinding wheel base 10 and the table 21 and relatively moving the grinding wheel 11 and the rotary truer 31 in the Z-axis direction and the X-axis direction. Here, the “tip position” of the rotary truer 31 is a portion of the outer peripheral surface of the rotary truer 31 that is closest to the outer peripheral surface of the grinding wheel 11. In the truing device 30, the number of rotations of the rotary truer 31 is controlled by the control device 40.

  The control device 40 is configured by a CPU, a ROM, and the like (not shown), and stores system programs, various data, grinding conditions, truing conditions, and the like. Various data including a contact signal from the AE sensor 33 is input to the control device 40 via the input device. In the grinding process, the control device 40 NC-controls the Z-axis position of the grindstone table 10, the X-axis direction position of the workpiece support device 20, and the rotation of the headstock 22. The control device 40 controls the rotation of the rotary truer 31 by rotating the built-in motor of the truing device 30.

  Thus, the grinding machine 1 grinds the outer peripheral surface of the workpiece W by controlling the position of each axis of the grinding wheel base 10 with respect to the workpiece W while rotating the grinding wheel 11 by the control device 40. Moreover, the control apparatus 40 inputs the relative axial direction position and the relative radial direction position of the rotary truer 31 with respect to the grinding wheel 11 detected by the AE sensor 33 which is a detection means. And in the truing, the control apparatus 40 is the state which rotated the grinding wheel 11 and the rotary truer 31, and based on the relative axial direction position and relative radial direction position of the rotary truer 31, the Z-axis position of the grinding wheel base 10, And the X-axis direction position of the truing device 30 is NC-controlled, and the shape of the grinding wheel 11 is formed.

(True operation)
Next, the truing operation of the grinding wheel 11 in the truing device 30 of the grinding machine 1 described above will be described with reference to FIGS. When the start of truing of the grinding wheel 11 is instructed, the control device 40 executes the processing shown in FIG. First, the control device 40 outputs the control device to the grinding wheel platform 10 and the truing device 30 to drive the grinding wheel 11 and the rotary truer 31 to rotate at a predetermined number of revolutions (S10). The rotational speed of the grinding wheel 11 is the rotational speed at which the grinding wheel 11 is actually rotated during truing. Here, the rotation speed is set to be the same as the processing conditions when the grinding machine 1 performs grinding so that the state of mechanical vibration and heat generation does not fluctuate. Therefore, when this truing process is executed in series from the grinding process, the control device 40 controls to maintain the rotational speed of the grinding wheel 11.

  On the other hand, the rotational speed of the rotary truer 31 is a peripheral speed indexed at a predetermined ratio with respect to the peripheral speed of a truing part (part formed by the rotary truer 31) determined by the grinding wheel 11 and the outer diameter. Thus, the rotational speed calculated based on the outer diameter of the rotary truer 31 is set. And also in the position detection performed before truing, the rotary truer 31 is made to rotate with the rotational speed calculated as mentioned above.

  At this time, the grindstone shaft 12 that is the rotating shaft of the grinding wheel 11 and the truer shaft 32 that is the rotating shaft of the rotary truer 31 are in a parallel state. The grinding machine 1 illustrated in the present embodiment is configured such that the grindstone shaft 12 and the truer shaft 32 are always maintained in parallel, but the axis parallel to the Y axis orthogonal to the X axis and the Z axis. In the case of having a mechanism for rotating a grindstone table or a truing device around, control is performed so that the respective axes are parallel as described above. Thereby, the axial direction end surface of the core part 111 of the grinding wheel 11 and the axial direction front end surface of the detection part 311b in the core part 311 of the rotary truer 31 are in a state of facing each other.

  Next, the control device 40 is configured so that the peripheral portion of the end surface of the core portion 111 of the grinding wheel 11 is positioned on the extension of the detection portion 311b, that is, the entire end surface of the detection portion 311b is the core portion as viewed from the Z-axis direction. The grinding wheel 11 and the rotary truer 31 are positioned in the Z-axis direction so as to be included in the inner periphery of 111 (S20). Then, in the state where both the grinding wheel 11 and the rotary truer 31 are rotated and the rotary shafts 12 and 32 are maintained in parallel, as shown in FIG. Let

  Thereafter, when the end surface of the core portion 111 of the grinding wheel 11 and the entire end surface of the detection portion 311b of the rotary truer 31 come into contact with each other, the AE sensor 33 detects an AE wave. When the AE wave is detected by the AE sensor 33, the control device 40 acquires the current position of the table 21 that moves the rotary truer 31 in the X-axis direction. Thereby, the control apparatus 40 detects the relative axial direction position of the grinding wheel 11 and the rotary truer 31 (S30), and memorize | stores it in memory, such as RAM.

  Subsequently, the control device 40 moves the grinding wheel 11 and the rotary tourer 31 in the X-axis direction so that the distal end portion of the outer peripheral surface of the grinding wheel 11 is positioned in the axial range from the root portion to the distal end portion of the detection unit 311b. Positioning is performed (S40). Then, in a state where both the grinding wheel 11 and the rotary truer 31 are rotated, they are moved relative to each other in the Z-axis direction as shown in FIG.

  Thereafter, when the tip of the grinding wheel 11 and the outer peripheral surface of the detection unit 311b come into contact with each other, the AE sensor 33 detects an AE wave. When the AE wave is detected by the AE sensor 33, the control device 40 acquires the current position of the grinding wheel base 10 that moves the grinding wheel 11 in the Z-axis direction. Thereby, the control apparatus 40 detects the relative radial direction position of the grinding wheel 11 and the rotary truer 31 (S50), and memorize | stores it in memory.

  And the control apparatus 40 is controlled so that the rotation speed of the grinding wheel 11 and the rotary truer 31 controlled in S10 may be maintained. Further, the control device 40 sets a truing start reference position based on the relative axial direction position (X-axis direction position) detected in S30 and the relative radial direction position (Z-axis direction position) detected in S50, As shown in FIG. 4, truing is performed by controlling the relative movement of the rotary truer 31 with respect to the grinding wheel 11 (S60). FIG. 4 illustrates a case where at least a part of the tip of the grinding wheel 11 is formed in an arc shape.

  Here, the relative X-axis direction position of the grinding wheel 11 and the rotary truer 31 detected in S30 includes the amount of thermal displacement in the axial direction of the grinding wheel 11 and the rotary truer 31. Similarly, the wear amount of the grinding wheel 11 is included in the relative Z-axis direction position of the grinding wheel 11 and the rotary truer 31 detected in S50. In this manner, the grinding machine 1 sets the truing start reference position by incorporating a positioning error caused by wear or thermal displacement of each part, thereby improving the truing accuracy.

(Effects of grinding machine truing device)
According to the truing device 30 of the grinding machine 1 described above, truing is performed by controlling based on the relative axial direction position of the rotary truer 31 with respect to the grinding wheel 11 detected by the AE sensor 33 which is a detecting means. The relative axial direction position of the rotary truer 31 is detected by bringing the end faces of the core portion 111 of the grinding wheel 11 and the detecting portion 311b of the rotary truer 31 into contact with each other while maintaining the grindstone shaft 12 and the truer shaft 32 in parallel. It is a thing. Thereby, the relative axial direction position of the rotary truer 31 relative to the grinding wheel 11 can be detected more accurately in consideration of the thermal displacement of the tip position of the rotary truer 31 and the thermal displacement of the grinding wheel 11 in the axial direction.

  Therefore, the control means controls the relative position of the rotary truer 31 and the grinding wheel 11 based on the relative axial direction position and the detected relative radial direction position, so that the truing start reference position of the rotary truer 31 with respect to the grinding wheel 11 is reached. Can be set more accurately. Therefore, the truing device 30 can reduce the influence of thermal displacement due to the speeding up of the rotational speed required for grinding and truing, and can perform truing with higher accuracy. Thereby, the removal amount of the grinding wheel 11 in truing can be suppressed to the minimum, and the life of the grinding wheel 11 can be prolonged. And by using such a grinding wheel 11 for grinding, grinding can be performed with higher accuracy.

  Here, in truing, the rotational speed of the grinding wheel 11 is set in the same manner as the processing conditions for grinding the workpiece W. Further, the rotational speed of the rotary truer 31 is set to the rotational speed determined at a predetermined ratio with respect to the peripheral speed of the truing part determined by the rotational speed of the grinding wheel 11. Thus, when detecting the relative axial direction positions of the grinding wheel 11 and the rotary truer 31, the state in which both members are rotated is the same as the state in which thermal displacement occurs in actual truing, and the thermal displacement in truing. The truing start reference position in consideration of the amount can be detected. And since the rotational speed of the grinding wheel 11 in truing is made the same as the rotational speed when grinding the workpiece W, the workpiece W after processing can be made highly accurate.

  In addition, since the end surface of the core portion 111 of the grinding wheel 11 and the entire end surface of the detection portion 311b of the rotary truer 31 are brought into contact with each other in a rotated state, a portion with a large relative speed always comes into contact. The detection sensitivity is improved by increasing the AE wave. If it does so, since it can shorten time until it detects an AE wave from contact, the amount of wear of the part made contact can be reduced. By reducing the amount of wear at the contacted portion, the positioning error of the rotary truer 31 relative to the grinding wheel 11 can be reduced, so that the truing start reference position can be made more accurate. Therefore, truing can be performed with higher accuracy. Moreover, the amount of wear of the detection part 311b can be made uniform by making the whole end surface of the detection part 311b contact.

  Further, the AE sensor 33 brings the tip end surface of the columnar detection portion 311 b formed in the core portion 311 of the rotary truer 31 into contact with the end surface of the core portion 111 of the grinding wheel 11, so that the rotary tourer 31 with respect to the grinding wheel 11 is brought into contact. The relative axial direction position was detected. Since the core part 311 is not a part worn by grinding and truing, the detection accuracy of the AE sensor 33 can be maintained. In contrast to the conventional one in which the grinding wheel and the detection pin are brought into contact with each other to detect the truing start reference position, in the present invention, the detection unit 311b is integrated with the rotary truer 31 that is more frequently replaced than the conventional detection pin. Since it provided, the detection part 311b will also become new with replacement | exchange of the rotary truer 31. FIG. Thereby, the wear amount of the detection part 311b can be made small compared with the conventional detection pin. Therefore, truing can be performed with high accuracy.

  Further, the outer diameter Dp of the detection portion 311b is formed to be smaller than the outer diameter Dc of the core body 311a in the core portion 311 of the rotary truer 31. The outer diameter Dp of the detection unit 311b is appropriately set in consideration of a detection method such as detecting an AE wave by the AE sensor 33, a peripheral speed, and the like. However, since the detection unit 311b rotates integrally with the core body 311a, the detection unit 311b is affected by the centrifugal force associated with the rotation. Therefore, by making the outer diameter Dp of the detection unit 311b at least smaller than the outer diameter Dc of the core body 311a, the centrifugal force acting on the detection unit 311b can be reduced, and the occurrence of vibration and the like can be prevented. Thereby, since the AE sensor 33 can stabilize operation | movement more, favorable detection accuracy can be maintained.

  Moreover, at the time of truing by the control apparatus 40, at least one part of the outer peripheral surface of the grinding wheel 11 shall be shape | molded by circular arc shape. As described above, the grinding wheel shaft 12 of the grinding wheel 11 and the truer shaft 32 of the rotary tourer 31 are affected by heat generated by a driving device such as a motor or a bearing, so that the grinding wheel 11 or the rotary tool 31 that supports the shaft is axial. Displace to. When such a thermal displacement occurs, the shape of the grinding wheel 11 to be formed is a non-cylindrical shape, that is, a tapered grinding wheel, an angular grinding wheel, or a grinding wheel having a part formed in an arc shape at least partially. In addition, the effect on truing due to thermal displacement increases.

  Conventionally, in order to allow thermal displacement of the grinding wheel or the rotary truer, it has been dealt with by setting the cutting depth deep so as to increase the grinding amount (removal amount) of the grinding wheel in truing. On the other hand, according to the truing device 30 of the grinding machine 1 of this embodiment, the truing start reference position is more accurately taken into consideration of the axial thermal displacement and the radial thermal displacement of the grinding wheel 11 or the rotary truer 31. Therefore, even if the shape of the grinding wheel 11 is non-cylindrical, more accurate truing can be achieved, and the removal amount of the grinding wheel 11 in truing can be minimized. Therefore, it is possible to prolong the life of the grinding wheel 11 used for grinding.

<Modification of Embodiment>
In the present embodiment, the AE sensor 33 as detection means is provided on the truer shaft 32 of the truing device 30. On the other hand, the AE sensor can be installed as long as it can detect an AE wave generated when the grinding wheel 11 and the rotary truer 31 come into contact with each other. For example, the inner circumference of the grinding wheel shaft 12 of the grinding wheel base 10 can be installed. Or a bearing supporting the grindstone shaft 12 or the truer shaft 32 or its periphery. Further, although the AE sensor has been described as an example of the detecting means, other various sensors can be applied as long as it is possible to detect that the grinding wheel 11 and the rotary truer 31 are in contact with each other.

In addition, the detection unit 311 b that is a columnar unit that functions as a contact is formed on the core body 311 a of the core unit 311 of the rotary truer 31. On the other hand, you may make it the structure which does not have the detection part 311b, and may make it contact the end surfaces of the core part 111 of the grinding wheel 11 and the core part 311 of the rotary truer 31 directly, for example. Thus, when making the end surfaces of the core parts 111 and 311 contact each other directly, protrusion parts, such as a bolt of the core parts 111 and 311, contact the abrasive grain layer of the grinding wheel 11 or the rotary truer 31, and other site | parts. Any configuration is acceptable. Specifically, on the end surfaces of the core portions 111 and 311, the protruding portion may be disposed on the radially inner side and the flat portion may be disposed on the radially outer side. Even in such a configuration, the core portions 111 and 311 of both the members 11 and 31 are thermally displaced in the axial direction when the rotation shaft is thermally deformed. The direction position will be detected.
Moreover, you may make it contact the outer peripheral surface of the core part 111 of the grinding wheel 11 and the outer peripheral surface of the core part 311 of the rotary truer 31 directly. In the case where the outer peripheral surfaces of the core portions 111 and 311 are brought into direct contact with each other, any structure other than the outer peripheral surfaces of the core portions 111 and 311 may be used. Specifically, the length in the rotation axis direction of the core portion 111 is made sufficiently longer than the length of the grinding wheel 11 in the rotation axis direction, and the rotation of the core portion 311 relative to the length in the rotation axis direction of the rotary tourer 31 The length in the axial direction may be sufficiently long.

  Moreover, since the above-mentioned columnar portion is intended for suitably bringing the end faces of the grinding wheel 11 and the rotary truer 31 into contact with each other, it may be provided on one member of the grinding wheel 11 and the rotary truer 31. . That is, a columnar portion similar to that of the present embodiment may be formed on the core portion 111 of the grinding wheel 11. Further, this columnar portion may be provided in both the core portion 111 of the grinding wheel 11 and the core portion 311 of the rotary truer 31.

  Further, the columnar detection part 311b is formed so that the outer diameter Dp is smaller than the outer diameter Dc of the core body 311a. This is intended to prevent the detection unit 311b from interfering with members other than the detection target. On the other hand, in order to further improve the detection sensitivity, for example, the outer diameter Dp may be appropriately set in order to increase the peripheral speed of the detection unit at the same rotational speed. In this case, the outer diameter Dp of the detection unit 311b may be the same or larger than the outer diameter Dc of the core body 311a where the detection unit 311b is formed.

  In order to detect the relative axial direction position of the grinding wheel 11 and the rotary truer 31, in this embodiment, the core part 111 of the grinding wheel 11 and the detection part 311b of the rotary truer 31 are brought into contact. 31 core parts 111 and 311 are brought into direct contact with each other. On the other hand, it is good also as a structure which makes the core part of one member contact end surfaces other than the core part of the other member. For example, the detection unit 311 b formed on the core unit 311 of the rotary truer 31 may be brought into contact with the abrasive grain layer 112 formed on the outer periphery of the core unit 111 in the grinding wheel 11. The axial end surface of the abrasive grain layer 112 of the grinding wheel 11 is a portion where wear due to grinding and truing is small, but from the viewpoint of maintaining good detection sensitivity, as illustrated in the present embodiment, the core portion The structure which contacts each other is suitable.

  In the present embodiment, the grinding wheel 11 is formed such that at least a part of the outer peripheral surface is formed in an arc shape during truing. On the other hand, for example, the grinding wheel 11 may be formed into a cylindrical shape, a tapered shape, or an outer shape of an angular shape grinding wheel used for an angular grinding machine. When the outer peripheral shape is cylindrical, even if thermal displacement occurs in the grinding wheel 11 or the rotary truer 31, it is possible to cope with this by securing a sufficient movement distance in the X-axis direction during truing. . However, by setting this movement distance shorter and appropriately, interference with other parts can be prevented and cycle time can be shortened. Therefore, it is useful to apply the truing device capable of correcting the thermal displacement of the present invention regardless of the shape of the outer peripheral surface of the grinding wheel 11.

  Further, in the present embodiment, the truer is the rotary truer 31 that is rotatably supported. On the other hand, the truer may be a fixed type such as a single stone truer or a pin-shaped truer installed in a range where the grinding wheel 11 can move in the grinding machine. In the case of such a fixed truer, the “truer” of the present invention includes a cutting edge part that contacts the grinding wheel, a truer body, and a holder part, and the detection means includes any part of the truer. The relative axial direction position is detected by contacting the axial end surface of the rotated grinding wheel. Thereby, considering the thermal displacement in the axial direction of the grinding wheel, the same effects as in the present embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1: Grinding machine, 2: Bed 10: Grinding wheel stand 11: Grinding wheel, 111: Core part, 112: Abrasive layer, 12: Grinding wheel axis 20: Workpiece support device 21: Table, 22: Headstock, 23: Center 24: chuck 25: center 30: truing device 31: rotary truer, 311: core part, 312: abrasive grain layer 311a: core body, 311b: detection part (columnar part)
32: Truer shaft, 33: AE sensor (detection means)
40: Control device (control means)
W: Workpiece, Aw: Central axis of grinding wheel, At: Central axis of rotary truer

Claims (5)

A truer that shapes the shape of a grinding wheel,
Detection means for detecting the relative axial direction position of the truer with respect to the grinding wheel by bringing the truer and the axial end surface of the grinding wheel in contact with each other while the grinding wheel is rotated,
Control means for controlling truing by controlling the relative movement of the truer with respect to the grinding wheel based on the detected relative axial position of the truer;
A truing device for a grinding machine, comprising: In claim 1,
The truer is a rotary truer supported rotatably.
In the state in which both members of the grinding wheel and the rotary truer are rotated and the rotation axes of the two are maintained in parallel with each other, the detection means is brought into contact with the end surfaces of the two members facing in the axial direction. A truing device for a grinding machine, wherein the relative axial direction position is detected. In claim 2,
The detection means detects the relative axial direction position of the rotary truer by bringing the end face of the core part of the grinding wheel facing the axial direction into contact with the end face of the core part of the rotary truer. Board truing device. In claim 2 or 3,
The core portion of one member of the grinding wheel and the rotary truer has a disk-shaped core body and a columnar shape extending in an axial direction from an end surface of the core body and having an outer diameter smaller than the outer diameter of the core body. And
The detecting means is configured to detect the relative axial direction position of the rotary truer by bringing the tip surface of the columnar portion into contact with the end face of the other member of the grinding wheel and the rotary truer. Truing device. In any one of Claims 1-4,
A truing apparatus for a grinding machine, wherein an outer peripheral surface of the grinding wheel is formed into a non-cylindrical shape during truing by the control means.

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