JP2005288593A - Positioning processing method and device for workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning processing method for a workpiece embodied in a simplified device constitution, capable of positioning the workpiece accurately and fixing firmly and performing the multi-face processing easily. <P>SOLUTION: The positioning processing method for the workpiece to position a cylinder block S in the specified position on a plane determined by two orthogonal axes and perform processing of the workpiece using a processing machine on the basis of the specified processing data, whereby the two ends of the block S in the longitudinal direction are positioned about the Z-axis direction by chucks 30 installed on a pallet in such a way that the longitudinal direction of the block is identical to the X-axis direction, then the position of the reference point for processing on the block in the X-axis direction is sensed by a touch sensor, followed by calculation of the dislocation of the sensed reference point for processing from the reference point for processing in the processing data, and upon correcting the processing data on the basis of the obtained amount of dislocation, the block S is processed by the processing machine. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a processing method and apparatus for processing a workpiece such as a cylinder block, and more specifically, positioning a workpiece that is processed by a processing machine based on predetermined processing data after the workpiece is positioned at a predetermined position. The present invention belongs to a technical field related to a processing method and apparatus.

  In general, a workpiece such as a cylinder block is roughly formed by casting or the like, and then subjected to roughing and various precision processings. When these processes are performed using a general machining center, the work is first fixed at a predetermined position on the pallet via a jig, and then the pallet is transported to a position corresponding to the processing data for positioning. Then, machining is performed by controlling the movement of the tool in accordance with predetermined machining data.

  Conventionally, when positioning a workpiece, the longitudinal direction (Y direction) of the workpiece is positioned by placing a specific shape portion of the workpiece at a predetermined position of the jig, and the longitudinal direction (Z direction) with respect to the processing machine. Determines the orientation of the workpiece and positions the front / rear direction (Z direction) on the pallet, and in the left / right direction (X direction) relative to the processing machine, moves the workpiece fixed position relative to the pallet on the jig in the X direction. Positioning was performed by.

  As an example of an apparatus for positioning such a workpiece, there is an apparatus disclosed in Patent Document 1. According to this, the apparatus has a pallet provided with a positioning device, and a pair of cylindrical chucks erected on the pallet so as to be movable in the X direction.

  In the cylindrical portion of the chuck, a plurality of convex portions are arranged on the circumference at equal intervals, and these convex portions can be protruded outward by the same amount at the same time. The chuck is erected so as to be movable on a slider extended in the X direction on the pallet, and a link mechanism is provided between the chucks. The link mechanism includes a first link member rotatably supported by a center pin provided at the center position of the pallet, and a pair of swinging links connected to both ends of the first link member and chucks on each side. The second link member is provided.

  With the above configuration, first, the chuck is inserted into the cylinder bore of the cylinder block and holds the block at a predetermined position in the Y-axis direction. Then, each chuck is inserted into the cylinder bore of the cylinder block. And the convex part with which each chuck | zipper was equipped is protruded to the same amount outside simultaneously, and a cylinder block is hold | maintained from the cylinder bore inside. At the same time, each chuck moves in the opposite direction along the slider via the link mechanism, and the center position in the X-axis direction of the cylinder bore into which the chuck is inserted overlaps the position in the X-axis direction of the center pin. Positioning of the workpiece with respect to the pallet in the axial direction and the Z-axis direction is completed.

JP-A-11-99425

  By the way, the apparatus disclosed in the above-mentioned patent document 1 is a link mechanism having a mechanism or a plurality of members for projecting protrusions provided in the chuck and the cylindrical portion for positioning the workpiece in the X-axis direction and the Z-axis direction. However, the mechanism of the apparatus is complicated, and there is a problem that the cost for constructing the apparatus increases in order to perform highly accurate positioning.

  Further, when machining the workpiece, the workpiece must be firmly fixed to the pallet, and if the fixation is weak, there is a problem that the workpiece is displaced during machining and the machining accuracy is lowered. Also in the apparatus described in Patent Document 1, the fixing strength is not sufficient only by the mechanism that protrudes the convex portion of the chuck, and a clamping mechanism that firmly fixes the workpiece from the outside during processing is required. As a result, when a rotary pallet is used to perform multi-surface machining, the clamping mechanism cannot be used to rotate the pallet, so the workpiece must be repositioned for each surface of the workpiece, Useless work and processing time increase.

  Furthermore, in order to ensure machining accuracy, the workpiece must be accurately fixed at a predetermined reference position corresponding to the machining data. However, when the workpiece is a cylinder block, for example, a casting obtained by cooling after injecting an aluminum alloy into a mold has a degree of expansion according to a change in temperature according to the season, time, environment, etc. The degree of shrinkage may change, resulting in individual differences in size and shape. The apparatus disclosed in Patent Document 1 performs positioning by overlapping the X-axis direction center position of the cylinder bore into which both chucks are inserted with the X-axis direction position of the center pin, but cannot cope with the individual differences as described above. Exact positioning is not possible.

  Therefore, the present invention reduces the cost as a simple device configuration, and also highly accurately positions the workpiece and firmly fixes the workpiece to the positioned position, and can easily perform multi-face machining and a workpiece positioning processing method. It is an object to provide such a device.

  In order to solve the above problems, the present invention is configured as follows.

  First, according to the first aspect of the present invention, a workpiece is positioned at a predetermined position on a plane determined by two orthogonal axes, and the workpiece is processed by a processing machine based on predetermined processing data. In the positioning processing method, the both ends of the workpiece in the X-axis direction in the horizontal direction are positioned in the Z-axis direction of the workpiece in the horizontal direction orthogonal to the X-axis direction by the positioning means provided in the workpiece pallet. The position of the workpiece reference point of the workpiece in the X-axis direction of the workpiece is detected by the position detection means, and the deviation amount between the detected machining reference point and the machining reference point on the machining data is calculated, and based on the calculated deviation amount After processing data is corrected, the workpiece is processed by a processing machine.

  Next, according to a second aspect of the present invention, there is provided the workpiece positioning processing method according to the first aspect, wherein the position detecting means is mounted on the spindle of the processing machine, and the workpiece is moved in the X-axis direction by moving the spindle. The position of the machining reference point is detected, and the amount of deviation of the machining reference point is calculated based on the amount of movement of the spindle when the position is detected.

  Next, the invention described in claim 3 is the workpiece positioning method according to claim 1 or 2, wherein the workpiece is a cylinder block of the engine, and is arranged at both ends of the block in the X-axis direction. Positioning means is inserted into the cylinder bore to position the Z-axis direction orthogonal to the bore line direction, and the position detection means is the position of the workpiece reference point set in the cylinder bore at the center of the cylinder block in the X-axis direction. Is detected.

  Next, according to a fourth aspect of the present invention, in the workpiece positioning method according to the third aspect, the positioning means includes an expansion member that extends in the Z-axis direction of the workpiece and abuts against the inner wall of the cylinder bore portion. It is characterized by being.

  Next, the invention according to claim 5 is the workpiece positioning method according to claim 4, wherein the work pallet is provided with a fixing jig for supporting the cylinder block from below, and the expansion member of the positioning means is provided. The cylinder block is fixed to the fixing jig and clamped by moving the expansion member downward while expanding.

  Next, according to a sixth aspect of the present invention, in the work positioning method according to any one of the third to fifth aspects, the work pallet includes any one of the cylinder bore portions excluding the cylinder bore portion into which the positioning means is inserted. A guide means for inserting into the cylinder bore is provided, and when the positioning means is inserted into the cylinder bore, the guide means is inserted into the cylinder bore first to guide the positioning means.

  Next, according to the seventh aspect of the present invention, the workpiece is positioned at a predetermined position on a plane determined by two orthogonal axes, and the workpiece is processed by a processing machine based on predetermined processing data. A processing apparatus, a workpiece pallet, and a positioning provided in the workpiece pallet for positioning the workpiece in the Z-axis direction in the horizontal direction perpendicular to the X-axis direction at both ends in the X-axis direction in the horizontal direction of the workpiece A position detecting means for detecting the position of the machining reference point of the workpiece in the X-axis direction of the workpiece by the position detecting means, and calculating a deviation amount between the detected machining reference point and the machining reference point on the machining data; Processing data correction means for correcting the processing data based on the calculated deviation amount is provided.

  Next, according to an eighth aspect of the present invention, in the workpiece positioning processing apparatus according to the seventh aspect, the position detecting means is mounted on the spindle of the processing machine, and the workpiece in the X-axis direction of the workpiece is moved by the movement of the spindle. The position of the machining reference point is detected, and the deviation amount of the machining reference point is calculated based on the amount of movement of the spindle.

  Next, the invention described in claim 9 is the workpiece positioning apparatus according to claim 7 or claim 8, wherein the workpiece is a cylinder block of an engine, and is arranged at both ends of the block in the X-axis direction. Positioning means is inserted into the cylinder bore to position the Z-axis direction orthogonal to the bore line direction, and the position detection means is the position of the workpiece reference point set in the cylinder bore at the center of the cylinder block in the X-axis direction. Is detected.

  Next, the invention described in claim 10 is the workpiece positioning apparatus according to claim 9, wherein the positioning means includes an expansion member that extends in the Z-axis direction of the workpiece and abuts against the inner wall of the cylinder bore portion. It is characterized by being.

  Next, according to an eleventh aspect of the present invention, in the workpiece positioning processing apparatus according to the tenth aspect, the work pallet is provided with a fixing jig for supporting the cylinder block from below, and an expansion member of the positioning means is provided. The cylinder block is fixed to the fixing jig and clamped by moving the expansion member downward while expanding.

  According to a twelfth aspect of the present invention, in the workpiece positioning apparatus according to any of the ninth to eleventh aspects, the work pallet is inserted into any of the cylinder bore portions excluding the cylinder bore portion into which the positioning means is inserted. Guide means is provided, and when the positioning means is inserted into the cylinder bore portion, the guide means is first inserted into the cylinder bore portion to guide the positioning means.

  First, according to the first aspect of the present invention, the workpiece on the workpiece pallet is first determined by positioning the workpiece in the Z-axis direction in the horizontal direction perpendicular to the X-axis direction in the horizontal direction by the positioning means. Is determined. At this time, by positioning both ends of the workpiece in the X-axis direction, the directionality of the workpiece can be easily corrected and the workpiece can be held more stably.

  Next, the position of the workpiece reference point of the workpiece in the X-axis direction of the workpiece is detected by the position detection means, and the deviation amount between the detected machining reference point and the machining reference point on the machining data is calculated, and the calculated deviation amount By correcting the machining data based on the above, it is possible to accurately perform a predetermined machining at a predetermined position of the workpiece according to the data. As described above, since the mechanical positioning of the workpiece is performed only in the Z-axis direction of the workpiece, the positioning device can be simplified and the cost for constructing the device can be reduced.

  In addition, in the X-axis direction of the workpiece, the amount of deviation is detected by the position detecting means with respect to the deviation of the positioning position by the positioning means and the deviation of the machining reference point caused by the individual difference of the work due to the expansion and contraction of the work. With the configuration in which the machining data is corrected based on the above, high-accuracy positioning can be easily performed according to the displacement of the positioning position and the individual difference of the workpiece, and machining accuracy can be ensured.

  Next, according to the second aspect of the present invention, since the position and amount of movement of the spindle of the processing machine are known parameters, a position detecting means is mounted on the spindle, and the workpiece reference point of the workpiece is obtained by moving the spindle. The position in the X-axis direction is detected, the amount of deviation is calculated based on the amount of movement of the spindle at the time of detection, and the data is corrected based on the calculated amount of deviation. This eliminates the need for an independent device as position detecting means, and allows the spindle to be used for both machining and position detection.

  Next, when the workpiece is a cylinder block, the positioning means is inserted into the cylinder bores at both ends of the cylinder block to position the X-axis direction orthogonal to the bore row direction. This determines the posture of the cylinder block on the work pallet. At this time, the orientation of the cylinder block can be easily corrected by inserting the positioning means into the cylinder bore portions at both ends of the cylinder block, and the cylinder block can be held more stably.

  In addition, in the case of a cylinder block obtained by casting, the position error increases according to the degree of expansion and contraction of the casting as the machining location is further away from the machining reference point, but the machining reference point is located at the cylinder bore in the center of the cylinder block. Since the distance from the reference point to the farthest machining location is minimized, the position error at each machining location can be reduced, and the machining accuracy can be further improved.

  On the other hand, in order to stably hold the cylinder block, the positioning means holds the cylinder bores at both ends of the block, so the positioning means holds the workpiece in the cylinder bore out of the X-axis direction. The processing reference point of the central cylinder bore is not uniquely determined by the expansion and contraction of the casting. Accordingly, the position of the workpiece reference point in the X-axis direction is detected by the position detection means, and a deviation amount of the detected machining reference point with respect to the machining reference point on the machining data is calculated. Based on the calculated deviation amount By correcting the processing data and processing the cylinder block, it is possible to achieve both an improvement in processing accuracy and a reduction in position error at the processing location by stably holding the cylinder block.

  Next, according to the invention described in claim 4, the positioning means is provided with an expansion member that extends in the Z-axis direction and abuts against the inner wall of the cylinder bore portion, so that the positioning means is expanded in the positioning means inserted into the cylinder bore portions at both ends. The direction of the workpiece can be precisely and precisely adjusted by expanding the same amount in the Z-axis direction at the same time. Further, the expansion member presses the inner wall of the cylinder bore portion, so that the cylinder block can be held and fixed more stably.

  Next, according to the fifth aspect of the present invention, the expansion member and the cylinder bore portion are provided by having the fixing jig for supporting the cylinder block from below and moving the expansion member downward while expanding the expansion member. The cylinder block can be firmly fixed and clamped by pressing the cylinder block against a fixing jig by friction with the inner wall, and the machining accuracy can be improved without the cylinder block being wobbled or displaced during machining.

  In addition, by holding and fixing the cylinder block from the inside of the cylinder bore, there is no need for a mechanism for fixing the cylinder block from the outside. As a result, the workpiece can be arbitrarily rotated, and multi-face machining can be easily performed. Can do.

  Next, according to the sixth aspect of the present invention, when the positioning means is inserted into the cylinder bore portion, the guide means is first inserted into one of the cylinder bore portions excluding both ends into which the positioning means is inserted. By guiding the block, it is possible to prevent the cylinder block whose posture is largely lost from coming into direct contact with the positioning means. In other words, since the positioning means abuts from the inner surface of the cylinder bore portion and positions the workpiece of the cylinder block in the Z-axis direction, the accuracy of the outer surface is important, and the cylinder block abuts upon insertion by the guide means. It is possible to avoid damage and deformation of the outer surface of the positioning means.

  The invention described in claim 7 to claim 12 is an invention of a workpiece positioning processing apparatus corresponding to the invention of the workpiece positioning processing method according to any one of claims 1 to 6, and is similar to each other. The effect is obtained.

  Embodiments according to the present invention will be described below.

  FIG. 1 is an overall view of a machining center 1 that processes a cylinder block S for an in-line four-cylinder engine. The machining center 1 includes, as main components, a base 10, a column 11 that is movable on the base 10 in the X-axis direction, and a main shaft 12 that is supported so as to be movable in the Y direction with respect to the column 11. The table 13 is movable on the base 10 in the Z-axis direction, and the pallet 15 is rotatably supported on the table 13 via a rotation mechanism 14.

  The base 10 includes a pair of X-axis rails 20 and 20 extending horizontally in the X-axis direction, and a pair of Z-axis rails 21 and 21 extending in the Z-axis direction orthogonal to the X-axis rails in the horizontal plane. (Two orthogonal axes).

  The column 11 is movable along the X-axis rails 20 and 20 in the X-axis direction, and is provided with a pair of Y-axis rails 22 and 22 extending perpendicularly to the Y-axis direction. A slide member 23 is supported on the Y-axis rails 22 and 22 so as to be movable in the Y-axis direction. The main shaft 12 projects from the slide member 23 in the Z-axis direction. The main shaft 12 can be expanded and contracted in the Z-axis direction, and a rotating tool is attached to the tip of the main shaft 12 in a replaceable manner.

  The table 13 is movable along the Z-axis rails 20, 20. A rotation mechanism 14 is placed and fixed on the table 13, and the rotation mechanism 14 rotatably supports the pallet 15. . As shown in FIG. 2, the pallet 15 includes a pair of chucks 30 and 30 that are inserted into the first and fourth cylinder bore portions SB1 and SB4 (see FIG. 4) of the cylinder block S and hold the block S, When the chucks 30 and 30 are inserted, the chucks 30 and 30 are inserted into the second and third cylinder bores SB2 and SB3 first to correct the cylinder block S to an appropriate posture, and the chucks 30 and 30 are connected to the cylinder bores SB1 and SB4. A pair of guide members 31 and 31 for guiding are provided upright. The guide members 31 and 31 are provided so as to be higher than the chucks 30 and 30 in the Y direction, that is, in the insertion direction of the cylinder bore portions SB1 to SB4. Both chucks 30 and 30 and guide members 31 and 31 are arranged in series in the X-axis direction. A pair of openings 32, 32 for the hydraulic passage are provided on the side surface of the pallet 15.

  As shown in FIGS. 2 and 3, the chuck 30 includes a substantially U-shaped leg portion 40 that is fixed to the pallet 15, a step portion 41 provided on the upper portion of the leg portion 40, and the chuck 30. The fixing portion 42 is provided above the step portion 41, and the head portion 43 is provided above the fixing portion 42 and can move a predetermined amount with respect to the fixing portion 42 in the vertical direction. The head portion 43 includes a pair of expansion members 50 and 50 that can project the same amount in the direction opposite to the Z-axis direction, and incorporates a hydraulically operated taper mechanism (not shown) that projects the expansion members 50 and 50. To do. Further, the taper mechanism is configured such that the rod provided with the taper surface is lowered by the hydraulic pressure and is engaged with the taper surface of the rod to expand the expansion members 50 and 50.

  The step portion 41 has a pair of horizontal surfaces 51, 51 in the Z direction (see FIG. 3). The step portion 41 of the chuck 30 (the leftmost chuck in FIG. 2) to be inserted into the fourth cylinder bore portion SB4 includes A swing mechanism 52 is provided. As shown in FIG. 3, the swing mechanism 52 has a pin 61 projecting from the notch 60 provided in the step portion 41 in the X-axis direction, and the swing member 62 is swingably supported by the pin 61. Has been. At both ends in the Z-axis direction of the swing member 62, protrusions 63, 63 are provided that protrude somewhat above the horizontal surfaces 51, 51 of the step portion 41. The chuck 30 to be inserted into the first cylinder bore portion SB1 has a configuration in which the swing mechanism 52 is removed from the chuck 30 to be inserted into the fourth cylinder bore portion SB4.

  The guide member 31 has a leg portion 70 having the same configuration as the chuck 30, and an insertion portion 72 is provided above the leg portion 70 via a shaft 71. The insertion portion 72 has a tapered surface 72a at the upper end, and a notch 72b is provided on the other guide member side.

  Incidentally, as shown in FIG. 4, a touch sensor 80 is attached to the main shaft 12. The touch sensor 80 has a spherical probe 80a at the tip, and can transmit a detection signal when the probe abuts.

  On the other hand, as shown in FIG. 5, the cylinder block S to be machined is for an in-line four-cylinder engine and has four cylinder bore portions SB1 to SB4, and the first and fourth cylinder bore portions SB1 and SB4. A total of four fixed surfaces 90... 90 are provided on both sides of each. Each of the fixed surfaces 90... 90 extends horizontally and comes into contact with the horizontal surface 51 of the chuck 30 or the protrusion 63 of the swing mechanism 52.

  Next, the machining process and operational effects of the machining center 1 according to the present embodiment will be described.

  First, the cylinder block S is roughly formed by cooling after pouring aluminum alloy into the mold. At this time, the position accuracy and surface accuracy of the cylinder bores SB1 to SB4 can be improved by casting a cast iron cylinder liner at a predetermined bore axis position.

  On the other hand, the shape of the cylinder block S to be machined is defined by CAD, the shape data by CAD is analyzed by CAM, NC data for the machining shape of the cylinder block S is created, and the tool to be held is determined. Then, these NC data and tool data are transferred to the machining center 1 side. In the machining center 1, positioning control of the cylinder block S and machining control for moving the tool are performed.

  On the other hand, as positioning control of the cylinder block S, Z-axis direction positioning control for supplying hydraulic pressure to a built-in taper mechanism (not shown) of the chucks 30 and 30 and moving and stopping the table 13 to a predetermined position in the Z-axis direction, as will be described later. Data correction control in the X-axis direction is performed. As shown in FIG. 1, the rotation mechanism 14, the pallet 15, and the chucks 30 and 30 are integrally fixed to the table 13, and if the position of the table 13 in the Z direction is determined, the positions of the chucks 30 and 30 in the Z direction are also unique. Will be determined. The rotation mechanism 14 rotates and stops and fixes the cylinder block S in the horizontal direction. This is for performing multi-surface machining by rotating the cylinder block S, and rotation control is performed mainly every 90 degrees.

  Further, as control for performing processing, control for moving the column 11 in the X-axis direction, control for moving the slide member 23 in the Y-axis direction, and control for extending and contracting the main shaft 12 in the Z-axis direction are performed. As a result, the tip of the main shaft 12 can be moved three-dimensionally, and by attaching a tool to the tip of the main shaft 12, three-dimensional machining can be performed according to the NC data.

  On the other hand, the cylinder block S after the rough forming is inserted from above into the chucks 30 and 30 and the guide means 31 and 31 through the cylinder bores SB1 to SB4, but is taller than the chucks 30 and 30. The guide means 31, 31 is first inserted into the second and third cylinder bore portions SB2, SB3, and after correcting the posture of the cylinder block S, the chucks 30, 30 are connected to the first, fourth at both ends. It is inserted into the cylinder bores SB1 and SB4, respectively. In addition, when the cylinder block S whose posture is greatly disturbed is to be inserted into the chucks 30, 30, the guide means 31, 31 comes into contact first to prevent insertion into the chucks 30, 30, and as a result, the cylinder block S The contact of S with the chucks 30 and 30 can be prevented. As described above, by providing the guide means 31, the outer peripheral surface damage and deformation of the chuck 30, 30 that may be caused by the contact of the cylinder block S with the chuck 30, 30 can be prevented in advance. The holding accuracy and thus the machining accuracy can be ensured. Further, the cylinder block S can be guided more reliably by the tapered surface 72a provided in the insertion portion 72 of the guide member 31, and the data correction control in the X-axis direction described later is provided by providing the notch 72b. In this case, it is possible to obtain an effect that does not interfere with the movement of the touch sensor 80 at the time.

  Next, after the cylinder block S is inserted into the chucks 30, 30, the axial alignment of the cylinder block S for positioning the block S in the Z-axis direction and the fixing / clamping of the block S to the chucks 30, 30 are performed. Is controlled. The axial alignment and fixing / clamping are performed via expansion members 50 and 50 and a taper mechanism as shown in FIG. That is, when the rod of the taper mechanism is lowered downward by hydraulic control, the expansion members 50 and 50 expand in the Z-axis direction (see arrow A), and the head portion 43 moves toward the fixed portion 42 (see arrow B). . As a result, the expansion of the expansion members 50 and 50 can align the direction of the cylinder block S in the Z-axis direction, and the head portion 43 with the expansion members 50 and 50 abutting against the inner walls of the cylinder bore portions SB1 and SB4. Is lowered, and the chuck that inserts the four fixed surfaces 90... 90 provided in the cylinder block S into the first cylinder bore portion SB1 by friction with the inner walls of the cylinder bore portions SB1 and SB4 of the expansion members 50 and 50. 30, the chuck 30 inserted into the horizontal planes 51, 51 of the step 41 and the fourth cylinder bore SB 4 presses downward against the protrusions 63, 63 of the swing mechanism 52, and the position of the cylinder block S relative to the chucks 30, 30, Fix / clamp the posture.

  The alignment in the Z-axis direction is first performed as shown in FIG. 7 (a), with the axis connecting the cylindrical centers of the first and fourth cylinder bore portions SB1 and SB4 of the cylinder block S inserted in the chucks 30 and 30. Assuming that the line x ′ is deviated from the reference axis x connecting the cylindrical centers of the chucks 30, 30, both the chucks 30, 30 are made to simultaneously extend the expansion members 50, 50 in the Z-axis direction. By moving the same amount in the direction (see arrows C and C ′), as shown in FIG. 7B, the axial center line x ′ and the reference axial center line x coincide with each other. The axial alignment of the cylinder block S can be performed.

  Further, the fixed surfaces 90... 90 of the cylinder block S are formed with a certain degree of accuracy even in rough forming, and the fixed surfaces 90... 90 are placed on the horizontal planes 51. However, it is rare that the four fixed surfaces 90... 90 are on the same horizontal plane, and these fixed surfaces 90. Even if it is placed on the horizontal planes 51... 51 provided on 41, one fixing surface 90 is lifted, and the cylinder block S cannot be stably fixed. Therefore, in the step portion 41 of the chuck 30 inserted into the fourth cylinder bore portion SB4, the fixed surfaces 90, 90 are flexibly supported by the swing mechanism 52, and the fixed surfaces 90 ... 90 are not exactly on the same horizontal plane. However, since the swing member 62 swings and can support both the fixed surfaces 90 and 90 of the fourth cylinder bore side SB4, the cylinder block S can be stably supported and fixed to the chucks 30 and 30. (See FIG. 6).

  After the above alignment is completed, the table 13 is moved to a predetermined position in the Z-axis direction corresponding to the NC data, and the positioning of the cylinder block S in the Z-axis direction is completed.

  After the positioning in the Z-axis direction, data correction control in the X-axis direction is performed. That is, the machining reference point in the X-axis direction of the NC data is set at the center in the X-axis direction of the partition walls of the second and third cylinder bore portions SB2 and SB3 (the Z-axis is illustrated in FIGS. 7A and 7B). Position), the machining is performed based on the machining reference point. The position of the center point in the X-axis direction of the partition walls of the second and third cylinder bore portions SB2 and SB3 of the cylinder block S fixed to the chucks 30 and 30 ( The NC data is corrected based on how much the actual position is shifted from the machining reference point on the NC data.

  The data correction control in the X-axis direction is executed according to the flowchart shown in FIG. First, in step S1, the X coordinate of the inner wall surface of the second cylinder bore portion SB2 on the third cylinder bore portion SB3 side is detected. More specifically, as shown in FIG. 9, at the initial position, the probe 80a at the tip of the touch sensor 80 mounted on the spindle 12 is set to the zero point O, and this zero point O is in the Z-axis direction described above. It is on an axis passing through the center of each cylinder bore portion SB1 to SB4 of the aligned cylinder block S (see FIG. 7B). Then, the probe 80a is moved downward by a predetermined amount (a), then moved by a predetermined amount (b) in the X direction, and then moved downward by a predetermined amount (c). Next, the probe 80a is moved in the (−) X direction, and the moving distance L1 of the main shaft 12 until it contacts the wall surface of the second cylinder bore SB2 is detected. Then, the probe 80a is returned to the zero point O through the same path.

  Next, in step S2, the X coordinate of the inner wall surface of the third cylinder bore portion SB3 on the second cylinder bore portion SB2 side is detected. More specifically, as shown in FIG. 10, the probe 80a is moved downward by a predetermined amount (a), then moved by a predetermined amount (−b) in the X direction, and then moved downward by a predetermined amount (c). Next, the probe 80a is moved in the (+) X direction, and the moving distance L2 of the main shaft 12 until it contacts the wall surface of the third cylinder bore SB3 is detected. Then, the probe 80a is returned to the zero point O through the same path.

  Next, in step S3, the deviation D of the actual position of the machining reference point detected from the zero point O is calculated. That is, by using (L2−L1) / 2 using L1 obtained in step S1 and L2 detected in step S2, the amount of deviation D of the machining reference point with respect to the zero point O can be calculated. .

  Then, the process proceeds to step S4 to verify whether or not the deviation amount D calculated in step S3 is appropriate. That is, if the deviation amount D is within the range of α <D <β (α: negative value, β: positive value) set in advance as a reasonable allowable range of deviation amount, the deviation amount D is set to step S5. Based on this, NC data is corrected and machining is started. On the other hand, if the deviation D is outside the range of α <D <β, a measurement abnormality alarm is output in step S6, and the machining center 1 is stopped.

  As described above, first, by clamping both ends of the cylinder block S with the chucks 30 and 30, the directionality of the cylinder block S can be easily corrected so that the bore row direction coincides with the X-axis direction. Furthermore, the cylinder block S can be held more stably by clamping from the cylinder bore portions SB1 to SB4 at both ends.

  Further, the position of the machining reference point of the cylinder block S in the X-axis direction is detected by the touch sensor 80, a deviation amount D of the detected machining reference point with respect to the zero point O is calculated, and NC data is calculated based on the calculated deviation amount D. By correcting the above, it is possible to accurately perform a predetermined processing at a predetermined position of the cylinder block S according to the NC data.

  Thus, when the cylinder block S is positioned, the mechanical positioning of the block S is performed only in the Z-axis direction, so that the positioning device (chuck 30) can be simplified and the cost for constructing the device can be reduced. .

  Further, with respect to the X-axis direction, a deviation amount D with respect to a deviation of a processing reference point caused by an individual difference due to an expansion / contraction due to a deviation of a clamp position by the chucks 30, 30 and by extension members 50, 50 or a temperature of the cylinder block S, etc. Is detected by the touch sensor 80, and the NC data is corrected based on the deviation amount D, so that high-accuracy positioning can be easily performed according to the deviation of the clamp position and the individual difference of the cylinder block S. And processing accuracy can be ensured.

  On the other hand, in the machining center 1, since the position and amount of movement of the main shaft 12 are known parameters, a touch sensor 80 is attached to the main shaft 12, and the position of the machining reference point of the cylinder block S in the X-axis direction is moved by the movement of the main shaft 12. , And a deviation amount D of the machining reference point is calculated based on the amount of movement of the spindle 12 at the time of detection, and the NC data can be corrected. Accordingly, an independent device including the touch sensor 80 is not required, and the main shaft 12 can be used for both processing and position detection.

  Further, by inserting and holding the chucks 30 and 30 in the cylinder bore portions SB1 and SB4 at both ends of the cylinder block S, the rotation of the cylinder block S can be regulated and the cylinder block S can be held more stably. Processing accuracy can be improved.

  Further, in the case of the cylinder block S obtained by casting, the position error becomes larger according to the degree of expansion and contraction of the casting as the position to be machined is farther from the machining reference point, but the second and third cylinder bore portions SB2 are increased. , By setting the machining reference point in SB3, the distance from the reference point to each machining location tends to be minimized, so that the position error of each machining location can be reduced and the machining accuracy is further improved. can do.

  On the other hand, in order to hold the cylinder block S stably, the cylinder bores SB1 and SB4 at both ends are held by the chucks 30 and 30, so the chucks 30 and 30 are displaced in the X-axis direction within the cylinder bores SB1 and SB4. The processing reference point set at the intermediate portion of the cylinder bore portions SB2 and SB3 due to the expansion and contraction of the casting is not uniquely determined. Therefore, the position of the machining reference point in the X-axis direction is detected by the touch sensor 80, a deviation amount D with respect to the predetermined position of the detected machining reference point is calculated, and the NC data is corrected based on the calculated deviation amount D. By processing the cylinder block S, it is possible to achieve both an improvement in processing accuracy due to the stable holding of the cylinder block S and a reduction in position error at the processing location.

  Further, the chuck 30 includes expansion members 50 and 50 that extend in the Z-axis direction to the cylinder bore portions SB1 and SB4 and abut against the inner walls of the bore portions SB1 and SB4. By expanding the amount, the directionality of the cylinder block S can be adjusted strictly and precisely. Further, the expansion members 50 and 50 press the inner walls of the cylinder bore portions SB1 and SB4, so that the cylinder block S can be held and fixed more stably.

  Further, by holding and fixing the cylinder block S from the inside of the cylinder bore portions SB1 and SB4, a mechanism for clamping and fixing the cylinder block S from the outside is not required, and as a result, the cylinder block S can be arbitrarily set by the rotating mechanism 14. It can be rotated and multi-face machining can be easily performed.

  Furthermore, the chuck 30 has horizontal surfaces 51 and 51 and a swing member 62 that support the cylinder block S from below, and moves the expansion members 50 and 50 downward in a state where the expansion members 50 and 50 are expanded. Thus, the cylinder block S can be firmly fixed and clamped by friction between the expansion members 50 and 50 and the inner walls of the cylinder bore portions SB1 and SB4, and the cylinder block S does not wobble or shift during processing. Can be improved.

  The present invention is not limited to the cylinder block S for an in-line four-cylinder engine. Also, for workpieces other than the cylinder block S, a deviation amount from the machining reference point on the NC data by setting a machining reference point. Can be applied by correcting the NC data.

  The present invention reduces the cost as a simple device configuration, highly accurately positions the workpiece, firmly fixes the workpiece to the positioned position, and easily performs multi-face machining and an apparatus for the workpiece positioning processing. I will provide a. The present invention relates to a processing method and apparatus for processing a workpiece such as a cylinder block, and more specifically, positioning a workpiece that is processed by a processing machine based on predetermined processing data after the workpiece is positioned at a predetermined position. It is widely suitable for the technical field regarding a processing method and its apparatus.

1 is a perspective view showing an overall configuration of a machining center according to an embodiment of the present invention. It is a front view of the chuck | zipper and guide member which are the positioning means used for the said machining center. It is an expanded sectional side view of the state in which the said chuck | zipper was inserted in the cylinder bore part of the cylinder block which is a workpiece | work. It is the longitudinal cross-sectional view which looked at the operation state of the touch sensor with which the main axis | shaft was mounted | worn from the front. It is a bottom view of a cylinder block. It is a sectional side view similar to FIG. 3 which shows the state at the time of the expansion of the expansion member of the said chuck | zipper. It is explanatory drawing of the positioning of the Z-axis direction which is a workpiece | work carrying-in direction. It is a flowchart of data correction control in the X-axis direction. It is explanatory drawing at the time of deviation | shift amount detection by a touch sensor. It is explanatory drawing at the time of deviation | shift amount detection by a touch sensor.

Explanation of symbols

1 Processing machine (machining center)
12 Spindle 15 Work palette (pallet)
30 Positioning means (chuck)
31 Guide means (guide member)
50 Expansion member 51 Fixing jig (horizontal part)
80 Position detection means (touch sensor)
S Workpiece (Cylinder block)
SB1 to SB4 Cylinder bore

Claims (12)

  A workpiece positioning method for positioning a workpiece at a predetermined position on a plane determined by two orthogonal axes and processing the workpiece with a processing machine based on predetermined processing data, which is provided in a workpiece pallet Positioning means performs positioning in the Z-axis direction of the workpiece in the horizontal direction perpendicular to the X-axis direction at both ends in the X-axis direction in the horizontal direction of the workpiece, and then the workpiece reference point of the workpiece in the X-axis direction of the workpiece. The position is detected by the position detection means, the deviation amount between the detected machining reference point and the machining reference point on the machining data is calculated, the machining data is corrected based on the calculated deviation amount, and then the workpiece is machined. A method for positioning a workpiece, characterized by machining with   The position detection means is mounted on the spindle of the processing machine, detects the position of the machining reference point of the workpiece in the X-axis direction of the workpiece by moving the spindle, and determines the machining reference point based on the amount of movement of the spindle at the time of the position detection. The work positioning method according to claim 1, wherein a deviation amount is calculated.   The workpiece is a cylinder block of the engine. Positioning means is inserted into the cylinder bore portions at both ends in the X-axis direction of the block to position in the Z-axis direction perpendicular to the bore row direction. The work positioning method according to claim 1 or 2, wherein the position of the work reference point set in the central cylinder bore is detected in the X-axis direction of the work.   4. The workpiece positioning processing method according to claim 3, wherein the positioning means includes an expansion member that extends in the Z-axis direction of the workpiece and contacts the inner wall of the cylinder bore portion.   The work pallet is provided with a fixing jig that supports the cylinder block from below, and the cylinder block is fixed to the fixing jig and clamped by moving the expansion member downward while expanding the expansion member of the positioning means. The workpiece positioning processing method according to claim 4, wherein the workpiece positioning processing method is performed.   The work pallet is provided with guide means to be inserted into any one of the cylinder bore portions excluding the cylinder bore portion into which the positioning means is inserted. When the positioning means is inserted into the cylinder bore portion, the guide means is inserted into the cylinder bore portion first. 6. The work positioning method according to claim 3, wherein the positioning means is guided.   A workpiece positioning apparatus for positioning a workpiece at a predetermined position on a plane determined by two orthogonal axes and processing the workpiece with a processing machine based on predetermined processing data, the workpiece pallet and the workpiece Positioning means provided on the pallet for positioning the workpiece in the Z-axis direction in the horizontal direction perpendicular to the X-axis direction on both ends in the X-axis direction in the horizontal direction of the workpiece, and machining the workpiece in the X-axis direction of the workpiece The position detection means that detects the position of the reference point by the position detection means, the amount of deviation between the detected machining reference point and the machining reference point on the machining data is calculated, and the machining data is corrected based on the calculated deviation amount A workpiece positioning processing apparatus, comprising: a processing data correction means for processing.   The position detection means is mounted on the spindle of the processing machine, detects the position of the machining reference point of the workpiece in the X-axis direction of the workpiece by moving the spindle, and calculates the deviation amount of the machining reference point based on the movement amount of the spindle. The workpiece positioning apparatus according to claim 7, wherein   The workpiece is a cylinder block of the engine. Positioning means is inserted into the cylinder bore portions at both ends in the X-axis direction of the block to position in the Z-axis direction perpendicular to the bore row direction. The work positioning processing apparatus according to claim 7 or 8, wherein a position of a work reference point set in a central cylinder bore part is detected in the X-axis direction of the work.   10. The workpiece positioning apparatus according to claim 9, wherein the positioning means includes an expansion member that extends in the Z-axis direction of the workpiece and abuts against the inner wall of the cylinder bore portion.   The work pallet is provided with a fixing jig that supports the cylinder block from below, and the cylinder block is fixed to the fixing jig and clamped by moving the expansion member downward while expanding the expansion member of the positioning means. The workpiece positioning apparatus according to claim 10, wherein   The work pallet is provided with guide means to be inserted into any one of the cylinder bore portions excluding the cylinder bore portion into which the positioning means is inserted. When the positioning means is inserted into the cylinder bore portion, the guide means is inserted into the cylinder bore portion first. 12. The workpiece positioning apparatus according to claim 9, wherein the positioning means is guided.

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