JP2006095687A - Sizing control method and device of machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sizing control method and a device for it, performing high-precision grinding, especially improving finishing accuracy and the roundness in twin-head grinding for independently grinding two parts of the same workpiece at the same time such as different crank pins of crankshaft by two wheel spindle stocks. <P>SOLUTION: The wheel spindle stock of a machined part earlier reaching the final target size in the next process before a spark-out process sizing control method and device is once moved backward by a predetermined amount, and when the other machined part reaches the final target size, the wheel spindle stock thereof is moved backward by a predetermined amount. After that, spark-out is performed by both wheel spindle stocks at the same time to surely perform spark-out. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a twin head crankpin constant-size grinding control method and apparatus capable of simultaneously and independently grinding crankpins having different crankshafts by two grinding wheel platforms.

  A twin head crankpin grinding method that can grind crankpins having different crankshafts simultaneously and independently by two grindstone heads is already known from Japanese Patent Application Laid-Open No. 54-71495. The crankpin part of the crankshaft is pivoted around the journal part of the crankshaft, so when machining while directly measuring the machining part, use a follow-up type sizing device described later, and each machining part A method of controlling the feed of the corresponding grinding wheel base on the basis of a signal generated from the sizing device every time a predetermined dimension is reached is adopted.

  In the above-described twin head crankpin grinding machine, since the processing by each grinding wheel base is performed independently, the grinding processing by each grinding wheel base may not proceed simultaneously depending on the state of the workpiece, the state of the grinding wheel, and the like. Therefore, even if one side is sparked out, that is, the cut is zero, the work piece is resisted by the grindstone of the other grindstone table, and the work piece is in a bent state. This will affect the finishing accuracy and roundness of the crankpin. Moreover, if the other grindstone base is maintained in the spark-out state until the other has completed the spark-out, it will be overcut.

  Accordingly, an object of the present invention is to provide high-precision grinding in twin head grinding, in which two places of the same workpiece, such as crank pins with different crankshafts, can be simultaneously and independently ground by two grinding wheel platforms. In particular, it is to provide a sizing processing control method capable of improving finishing accuracy and roundness and an apparatus therefor.

  In order to solve the above-mentioned problems, the sizing grinding control method for a machine tool according to the present invention provides different machining locations on the same workpiece by at least two tool tables provided with sizing devices at corresponding positions. This is a machining control method for machine tools that can perform machining independently at the same time. The tool table at the machining point that has reached the target dimension is retracted by a predetermined amount, and the tool table at all machining points is retracted by a predetermined amount. After that, the next process is performed at the same time.

  Further, in addition to the above features, at least in one stage before the final process, the tool table at the machining location that has previously reached the target dimension is retracted by a predetermined amount, and after all the tool tables have retracted by a predetermined amount, the next process is performed. It is characterized by the fact that it is performed at the same time. In addition, the tool table at the machining location that finally reached the target dimension is simultaneously processed with the other tool table at the same time without retreating a predetermined amount. It is what.

  Further, the sizing grinding control method for a machine tool according to the present invention simultaneously and independently grinds different machining locations of the same workpiece at the same time by two grindstone platforms equipped with sizing devices at corresponding positions. A twin head grinder capable of controlling the sizing process, and at least one stage before performing the final spark-out process, the grindstone table at the machining point where the measured value has reached the target dimension is retracted by a predetermined amount, The spark-out process is performed at the same time after both of the grindstone tables are retracted by a predetermined amount. Furthermore, in at least one stage before performing the final spark-out process, the grindstone table at the machining location where the measured value has reached the target dimension is retracted by a predetermined amount, and when the other machining location reaches the target value, The retreating wheel head is advanced by the amount of retraction, and the spark-out process is simultaneously performed by both of the wheel heads.

  Further, the sizing grinding control device for a machine tool according to the present invention is a twin-head crank capable of simultaneously and independently grinding crankpins having different crankshafts by two grinding wheel platforms each having a tracking sizing device. In the pin grinding machine, means for indexing the two wheel heads to the processing position, means for moving forward to grind the two wheel heads, and at least one stage before the final grinding on the two wheel heads at the same time Means for measuring an object, means for retreating a grindstone base at a machining location where the measurement result first reaches the target dimension, and one retreating grindstone at the same time when the measurement result at the other machining location reaches the target dimension It is characterized by comprising means for advancing the base by the amount retracted and means for simultaneously performing a spark-out process by both grinding wheel bases.

  The present invention relates to a machining control method for a machine tool capable of simultaneously independently machining different machining locations of the same workpiece by at least two tool stands provided with a sizing device at corresponding positions. Since the tool table at the location where the target dimension has been reached first is retracted by a predetermined amount and the tool table at all locations has been retracted by a predetermined amount, the next process is performed simultaneously. Since the resistance becomes uniform, there is no possibility of adversely affecting the roundness and the like, and high-precision grinding can be performed.

  In addition, at least in the first stage before the final process, the tool table at the location where the target dimension has been reached first is retracted by a predetermined amount, and after all the tool tables have retracted by a predetermined amount, the next process is performed simultaneously, Finished dimensions of all machining points can be machined with high accuracy.

  In addition, the cycle time can be shortened with high accuracy by performing the next process at the same time together with the other tool table without retreating the tool table at the point where the target dimension is finally reached. .

  In addition, by applying the sizing processing control method of the present invention to a twin head grinding machine, its characteristic operation and effect can be made remarkable, and the spark-out process by two grinding wheel platforms can be performed simultaneously and reliably. Therefore, highly accurate grinding can be performed.

  In addition, since the grindstone head at the machining location where the measured value has reached the target dimension later is subjected to a spark-out process at the same time by using both grindstone wheels without retreating by a predetermined amount, the influence of machining accuracy due to bending is reduced and the cycle is reduced. Time can be shortened.

  An embodiment in which the machine tool sizing control method of the present invention is applied to a twin head crankpin grinding machine will be described below with reference to FIGS.

  As shown in FIG. 1, the twin head crankpin grinding machine is provided with grinding wheel bases 8 and 9 which are two right and left machining heads so as to be slidable in the left and right directions and the front and rear directions. A headstock 18 and a tailstock 17 that support a crankshaft W, which is a workpiece, are installed at positions parallel to the axis. That is, on the bed 1, a right Z-axis table 6 for placing the right grindstone table 8 on the Z-axis guide rail 2 in the longitudinal left-right direction (Z-axis direction) is slidably provided by the feed screw 3. In the same row, a left Z-axis table 7 on which the left grindstone base 9 is placed in the left-right direction (Z-axis direction) on the bed 1 is slidably provided by a feed screw 4. In each of the left and right Z-axis tables 6 and 7, grindstone tables 8 and 9 provided with grindstones 14 and 15 are rotatably driven in a longitudinal direction (X-axis direction) orthogonal to the longitudinal left-right direction (Z-axis direction). The feed screws 12 and 13 are slidably provided.

  A headstock 18 and a tailstock 17 are installed in the front longitudinal direction of the left and right grindstone heads 8 and 9, and a crankshaft W, which is a workpiece, is supported by a pair of centers therebetween. The spindle stock 18 is provided with a servo motor 18M for driving the rotation of the crankshaft so that the shaft end of the crankshaft W can be gripped and rotated by a chuck or the like. It is configured to support the W core.

  Each feed screw is provided with a servo motor with an encoder, and is controlled by a control device described later. That is, a servo motor 60 with an encoder 70 is provided at the end of the feed screw 3 for moving the right Z-axis table 6 on which the right grindstone table 8 is placed in the longitudinal left-right direction (Z-axis direction). The feed screw 4 for the axis table 7 is provided with a servo motor 68 with an encoder 72. On the left and right Z-axis tables 6 and 7, servo motors 44 with encoders 50 and 52 are attached to end portions of feed screws 12 and 13 for sliding in the front-rear direction (X-axis direction) of the grinding wheel bases 8 and 9, respectively. 48 is provided. The grindstones 8 and 9 are supported so that the grindstones 14 and 15 are rotationally driven. Of course, a driving motor for driving the grindstone is built in the grindstone tables 8 and 9.

  The schematic configuration of the twin head crankpin grinding machine according to the embodiment of the present invention is as described above. The crankshaft W as a workpiece is supported between the headstock 18 and the tailstock 17, and the left and right Z axes The tables 6 and 7 are indexed by the servo motors 60 and 68 at the positions where the grindstones 14 and 15 are aligned and opposed to the processing positions of the crankshaft W, in FIG. 1, the crankpins CP (A) and CP (C). Next, the spindle drive servomotor 18M with the encoder 18E of the headstock 18 is rotated to control and rotate the crankshaft W. At that time, the crankshaft W is rotated about the axis of the bearing portion, that is, the center of the journal CP (e), so that the crank pins CP (a) to CP (c) which are machining points are centered on the journal CP (e). Will make a revolving turning motion. The X-axis direction feed screws 12 and 13 on the left and right tables 6 and 7 are moved forward and backward by the servo motors 44 and 48, respectively. At that time, since the crankpins CP (A) and (C) which are the machining locations are revolving and rotating, the grindstones 8 and 9 are moved back and forth in synchronization with the rotation of the spindle servomotor 18M by the control means. 14 and 15 are used for grinding. In accordance with the grinding operation, the servo motors 44 and 48 of the grinding wheel bases 8 and 9 give a cutting forward motion, and operate to gradually finish to the final finished dimensions.

  Further, in the twin head crankpin grinding machine of the embodiment of the present invention, a sizing device 20 is placed on the upper surface of each grindstone base 8 and 9 as shown in FIG. 2 in order to control the finishing dimension. Yes. This sizing device 20 is a well-known following type sizing device (for example, manufactured by Marposs, Italy) of a type that measures the dimensions of a processing part by following the crank pin that revolves and turns continuously. This will be described with reference to FIG.

  A support member 21 of the sizing device 20 is placed on the upper surface of the grindstone table 9, and a second arm 23 is pivotally supported at the tip of a first arm 22 that is pivotally supported by the support member 21 and extends forward of the grindstone 15. A measuring rod 28 for measuring is fixed to the tip of the second arm 23 at a right angle. The measuring rod 28 is composed of a V block 25 fixed to the tip thereof and in contact with the outer periphery of a crank pin CP (c) as a machining location, and a probe 27 provided at the center thereof so as to be able to advance and retract. The forward / backward movement is electrically detected and output as an electrical signal.

  A guide member 26 is fixed to the tip of the V block 25, and serves as a guide for engaging the V block 25 of the measuring rod 28 with the crankpin CP (c). The sizing device 20 is provided with an operating device for moving the measuring rod 28 to a rest position (two-dot chain line position) and a measurement position (solid line position).

  A hydraulic cylinder 31 is provided on the upper surface of the grindstone base 9, and the operation piece 30 mounted perpendicularly and offset to the rear end of the first arm 22 is pressed by the piston 32 of the cylinder 31 to thereby provide the first. The arm 22 is rotated upward and maintained at a rest position indicated by a two-dot chain line in FIG. At this time, since the second arm 23 is only pivotally supported at the tip of the first arm 22, the position cannot be maintained. Therefore, the third arm 24 is fixed below the tip of the first arm 22. The position of the second arm 23 is maintained at the rest position by the support protrusion 29 at the tip of the arm 24. When the measuring rod 28 is gradually lowered by returning the piston 32 of the hydraulic cylinder 31 from the rest position of the two-dot chain line and comes to the position of the crankpin CP (c), the guide member 26 is first moved to the crankpin CP (c). The crank pin CP (c) is engaged with the V block 25 along the guide member 26, and at this time, the second arm 23 is free to move away from the support protrusion 29 of the third arm 24. It can be turned. That is, the V block 25 is always engaged as the crankpin CP (c) revolves along a locus indicated by a one-dot chain line.

  Next, a control device for a twin head crankpin grinder according to an embodiment of the present invention will be described. As shown in FIG. 3, the present control system includes a numerical controller device 78. The numerical controller 78 includes a right grinding wheel control CPU 80, a left grinding wheel control CPU 90, a ROMI 09, and a RAM 111 that are connected to each other via a bus 88. It is configured to be connectable to.

  An X-axis servo motor control circuit 84 and a Z-axis servo motor control circuit 86 are connected to the right grinding wheel control CPU 80 via an interface 82. A right X-axis servo motor 44 is connected to the X-axis servo motor control circuit 84, and the encoder 50 is arranged on the right X-axis servo motor 44 as described above. A motor control circuit 84 is connected. The Z-axis servo motor control circuit 86 is connected to the right Z-axis servo motor 60, and the right Z-axis servo motor is provided with the encoder 70 described above. The encoder 70 is connected to the Z-axis servo motor control circuit 86. It is connected to the.

  Further, an X-axis servo motor control circuit 94, a Z-axis servo motor control circuit 96, and a main-axis servo motor control circuit 98 are connected to the left grindstone control CPU 90 via an interface 92. A left X-axis servo motor 48 is connected to the X-axis servo motor control circuit 94, and an engoer 52 is disposed in the left X-axis servo motor 48, and the encoder 52 includes an X-axis servo motor control circuit 94. It is connected to the. The Z-axis servo motor control circuit 96 is connected to the left Z-axis servo motor 68, and the left Z-axis servo motor is provided with an encoder 72. The encoder 72 is connected to the Z-axis servo motor control circuit 96. ing.

  The spindle servo motor control circuit 98 is provided with a spindle servo motor 18M. The spindle servo motor 18M is provided with an encoder 18E. The encoder 18E is connected to the spindle servo motor control circuit 98. . Further, an input / output device 107 having a CRT 103 and a numeric keypad 105 is connected to the bus 88 via an interface 101. The ROM 109 stores system control programs and the like, and the RAM 111 stores processing programs and the like. In addition to the numerical controller 78, a sequence controller 112 is connected to the bus 88 via an interface 113, and the left and right sizing devices 20L and 20R provided on both the left and right grinding wheel platforms include AD converters. It is connected via the interface 114.

  Next, a specific control method that is a feature of the present invention will be described with reference to the flowchart of FIG. 4 showing the control steps. First, indexing is performed in order to align the left and right grinding wheel bases 8 and 9 with the crank pins CP (A) and CP (C) at the machining locations in accordance with a signal of machining start 120 (121). Next, both the grinding wheel bases 8 and 9 are fast-forwarded and advanced (122), and the grinding wheel bases 8 and 9 are coarsely fed from the stage where the grinding stones 14 and 15 come into contact with the processed portions of the crank pins CP (A) and CP (C). Advancement (123) is made, and the advancement of the grindstone table 20 is stopped once after a certain amount of grinding, and the sizing device 20 is inserted into the respective crank pins CP (A) and CP (C) (124). Then, fine grinding feed forward (125) is performed to perform fine grinding.

  In precision grinding, the dimension value is measured by the sizing device 20, and when one of the crank pins (for example, CP (a)) reaches the target dimension for finishing the precise grinding, that is, the sizing from either one of the sizing devices 20 is performed. When a signal is output (126), the corresponding grindstone base 8 is retracted (127) by a predetermined amount of 0.1 mm to 0.5 mm, and the grindstone 14 is separated from the crankpin CP (A). In the meantime, the other grinding wheel base 9 continues to perform precision grinding, and when the other crank pin CP (c) reaches the target dimension for finishing fine grinding (128), that is, from the other sizing device 20. When the fixed-size signal is output, the corresponding grindstone base 9 is also retracted (129) by a predetermined amount of 0.1 mm to 0.5 mm, and the grindstone 15 is separated from the crankpin CP (c).

  At the same time, both the grindstone heads 8 and 9 are advanced (130) by the retracted amount (0.1 mm to 0.5 mm), and at the same time, the spark-out (131) is performed, and the crank pins CP (A) and CP (C) After the grinding process is finished and the left and right grinding wheel platforms 8 and 9 are retracted by a certain amount (132), the sizing device is returned to the rest position (133), and the grinding wheel platforms 8 and 9 are retracted (134). Further, in step (135), when grinding of the next crank pins CP (B) and CP (D) remains (NO), the process returns to the first step again, and both wheel heads are connected to the crank pins. The grinding wheel bases 8 and 9 are indexed to positions to be aligned with CP (B) and CP (D) (121), the same grinding cycle is executed, and when grinding of all the crank pins is completed, both grinding wheel bases are restored to the original positions. Return to position (136) and all grinding cycles are completed (137).

  The above grinding cycle is shown in FIG. 5. The upper line shows the amount of cut by the left and right grinding wheel bases 8 and 9, and the lower line shows the diameter change of the crank pins CP (A) and CP (C). . Note that the upper line in FIG. 5 only shows the cutting amount of the grinding wheel head, and as described above, the grinding wheel bases 8 and 9 move back and forth in the X-axis direction in synchronization with the turning motion of the crank pin CP. However, a desired cutting amount is given and grinding is performed.

  From the stage (a) in which the grindstone comes into contact with the machining portion from the rapid feed forward, the coarse grinding feed forward is performed for about 8 revolutions of the crank pin CP, and the advance of the grindstone base 20 is stopped and fixed from the stage (b) in which a fixed amount of grinding is performed. The sizing device 20 is inserted (b to c), and then the dimension measurement is performed by the sizing device 20 while the crankpin is ground for about 5 rotations in the fine grinding feed forward. When the precision grinding finish target dimension is reached first, the grindstone base 8 corresponding to the crankpin CP (A) is retracted by a predetermined amount (0.1 mm to 0.5 mm) at (d1) (e1), The crankpin CP (c) is continuously subjected to precise grinding, and when the precision grinding finish target size is reached (d2), the grindstone base 9 corresponding to the crankpin CP (c) is also set to a predetermined amount (0.1 mm). Retreat (e2). Note that the lengths between d1-e1-f1-g1 and d2-d2-f1-g1 in FIG. 5 are enlarged for easy understanding.

  And if it confirms that both whetstone bases 8 and 9 retreated, both these whetstone bases 8 and 9 shall be advanced simultaneously (f1-g1, f2-g2) by the retreated amount (0.1 mm-0.5 mm). Then, both the grindstones 14 and 15 simultaneously perform the spark-out for about one or two rotations of the workpiece, finish the grinding of the crankpins CP (i) and CP (c) (h1, h2), and retract the grindstone tables 8 and 9 .

  In the case of the present invention, different crankpins CP (A) and CP (C) are simultaneously ground by the two left and right grinding wheel bases 8 and 9 that are individually controlled, and the processing progress is different. Become. Therefore, the diameter dimension of each crankpin CP (A) and CP (C) follows a locus as shown by the lower line in FIG. The crank pins CP (A) and CP (C), which are the workpieces W, have a diameter before grinding of Db and a finished diameter of Df.

  The first rough grinding and then the fine grinding are performed, but the grinding process by the two grinding wheel bases 8 and 9 is not exactly the same, so there is a difference in the difference Δd1 and Δd2 between the dimension at the end of the rough grinding and the finishing dimension Df. Out. Therefore, if fixed-size grinding is performed during precision grinding, it will be understood that there is a difference in the time required to reach the target dimension (Df + Δd3) for completion of precision grinding.

  At this time, the grinding wheel base 8 that has reached the target dimension for finishing fine grinding first is continued, and the next process is sparked out, that is, the cutting amount of the grinding wheel base 8 is made zero to eliminate the resistance from the grinding wheel 14 to the workpiece. Even if the finishing process for the deflection of the workpiece is performed, the workpiece W is still bent because the other grinding wheel base 9 is still incised during the fine grinding process. Therefore, the deflection of the workpiece W returns, that is, the spark-out performed in anticipation of springback is almost ineffective, and the spark-out cannot be performed as expected, and the finishing accuracy of the crankpin CP (A) Roundness will deteriorate.

  Therefore, as a feature of the present invention, the grindstone table 8 that has reached the fine grinding end target dimension first is retracted by a predetermined amount at one end, and waits until the other reaches the fine grinding end target dimension. At this time, the grindstone table 8 is not moving forward but moving back and forth in the X-axis direction according to the rotation of the workpiece. When the measurement dimension of the other crank pin CP (c) reaches the precision grinding target dimension, the corresponding grindstone base 9 is also retracted by a predetermined amount, so that the resistance applied to the workpiece W is eliminated, and the workpiece is deflected. Exclude.

  Thereafter, both the grinding wheel heads 8 and 9 are moved forward by the retracted amount, so that the workpiece W is simultaneously subjected to a spark-out for one to two revolutions, that is, grinding is performed by Δd3 corresponding to the deflection of the workpiece. (Δd3 in FIG. 5 is enlarged for easy understanding, and is actually a very small amount.) Therefore, since the load applied to the crankshaft W by the two grinding wheel bases is not biased at the time of sparking out, accuracy is improved. It is possible to perform a high final finishing process.

  Next, a second embodiment of the sizing processing control method according to the present invention will be described with reference to FIG. The outline is the same as in FIG. 4. First, indexing is performed in order to align the left and right grinding wheel bases with the crank pins CP (a) and CP (c), which are machining locations, according to a machining start (140) signal ( 141). Next, both the wheel heads 8 and 9 are fast-forwarded (142), and when the wheels come into contact with the processed parts of the respective crank pins, both wheel heads are moved forward to coarse grinding (143), and are fixed after a certain amount of grinding. The dimensioning device 20 is inserted into the crankpin portion (144). And fine grinding is performed by fine grinding feed advance (145), performing dimension measurement. When one of the measured dimensions of the left and right crankpins CP (A) and CP (C) reaches the precision grinding end target dimension first (146), the corresponding grinding wheel base 8 is retracted by a predetermined amount (147), The other crankpin CP (c), which is continuously performing fine grinding, is put on standby until the fine grinding finish target dimension is reached.

  Then, when the measured value of the other crank pin CP (c) reaches the precise grinding end target dimension (148), the grinding wheel base 9 which has been cut back by a predetermined amount with the cutting amount of the corresponding grinding wheel base 9 set to zero. 8 is advanced by the retreated amount (149), and both the grinding wheel heads perform a spark-out (150) for one or two rotations of the workpiece. At this time, while one of the grinding wheel bases 8 moves forward to a position where the sparking is performed, the other grinding wheel base 9 has a cut amount of zero, that is, is in a spark-out state, so there is a slight difference between the left and right spark-out times. However, there is no influence because the amount of retreat is very small. In addition, when the cutting amount of the final step, that is, the cutting amount of the fine grinding process is small (for example, φ2 μm / rev), since the load applied to the workpiece is small, the amount of bending is small, that is, the amount returned by springback is small. Therefore, even if the spark-out time is somewhat longer, there is no particular effect on the processing accuracy and roundness.

  Subsequent operation steps (151) to (156) are the same as steps (132) to (137) in FIG. As a result, the time for retreating the grindstone can be shortened, so that the cycle time can be shortened.

  Next, a third embodiment of the sizing processing control method according to the present invention will be described with reference to FIG. Since the outline is the same as FIG. 4 and FIG. 6, only different points will be described. Steps (160) to (166) are the same as steps (120) to (126) in FIG.

  When one of the left and right grinding wheel bases 8 and 9 reaches the precision grinding target dimension first in step (166), the left and right grinding wheel bases 8 and 9 are retracted by a predetermined amount (0.1 mm to 0.5 mm) at one end ( 167). Then, only the grindstone table 9 on the side that has not yet reached the precision grinding target dimension is again cut and advanced (168). When the precision grinding completion target dimension is reached (169), the workpiece is retracted again by a predetermined amount (170), and left and right The grindstone bases 8 and 9 are simultaneously moved forward (171) by a predetermined amount, and the left and right grindstones 14 and 15 simultaneously spark out the crank pins CP (i) and CP (c) (172).

  The following steps (173) to (178) are the same as steps (132) to (136) in FIG. In the embodiment of FIGS. 4 and 5, when the grindstone table 8 on the side that has previously reached the precision grinding target dimension is retracted, the resistance applied to the workpiece W changes and the amount of deflection of the workpiece W changes. Therefore, a change in the bending during the fine grinding process in the other grinding wheel table 9 may affect the machining accuracy. However, according to the third embodiment shown in FIG. Since the left and right grindstone heads are simultaneously retracted and the remaining grinding is performed again when the diameter reaches a fixed size, more accurate grinding can be performed.

  Next, a fourth embodiment of the sizing processing control method according to the present invention will be described with reference to FIG. The outline is the same as that in FIG. 4, and sizing control is also performed in rough grinding. First, indexing is performed in order to align the left and right grinding wheel bases 8 and 9 with the crank pins CP (A) and CP (C), which are the machining locations, in accordance with a signal of machining start (180) (181). Next, both the grinding wheel bases 8 and 9 are fast-forwarded and moved forward (182), and the grinding wheels 14 and 15 come into contact with the processed portions of the respective crank pins CP (A) and CP (C) to process the black skin on the workpiece surface. Then, the sizing device 20 is inserted into the crankpins CP (A) and CP (C) (183). Then, while performing the dimension measurement, both grinding wheel heads are moved forward in rough grinding (184), and one of the measured dimensions of the left and right crank pins CP (A) and CP (C) is set to the target dimension for finishing rough grinding first. When it reaches (185), the corresponding grinding wheel base 8 is retracted by a predetermined amount (186), and waits until the other crankpin CP (c) reaches the rough grinding end target dimension.

  When the measured value of the other crank pin CP (c) reaches the rough grinding end target dimension (187), the one grindstone table 8 that has been retracted by a predetermined amount is advanced (188), and the left and right grindstone tables 8, Then, 9 is finely fed, and the crankpins CP (A) and CP (C) are finely ground (189). Hereinafter, steps (190) to (201) are the same as those in the first embodiment of FIG. Therefore, even when the total machining allowance is small, there is no influence of bending, and more accurate grinding can be performed.

  (Other Embodiments) Although the above embodiment is applied to a twin head crankpin grinding machine, the machining control method of the present invention is not limited to the crankpin grinding, and two or more of the same workpiece are used. It can be applied to any machined part that can be processed at the same time. For example, it can also be applied to cylindrical mirrors, cam grinders, pin mirrors and cam mirrors using a cutter tool, which can simultaneously process crank pins and journals, plunge cut. It is.

The top view of the twin head crankpin grinder of this invention. The side view showing the sizing apparatus in the twin head crankpin grinding machine of this invention. The block diagram which shows the fixed-size process control apparatus of the twin head crankpin grinding machine of this invention. The control flowchart of the sizing process control of the twin head crankpin grinding machine of this invention. FIG. 3 is a cycle diagram of sizing processing control of the twin head crankpin grinding machine of the present invention. The control flowchart of the sizing processing control method in 2nd Embodiment. The control flowchart of the sizing processing control method in 3rd Embodiment. The control flowchart of the sizing processing control method in 4th Embodiment.

Explanation of symbols

1: Bed 8: Right grinding wheel base 9: Left grinding wheel base 14: Right grinding wheel 15: Left grinding wheel 17: Tailstock 18: Spindle base 22: Sizing device 25: V block 28: Measuring rod 27: Probe 78: Numerical control apparatus

Claims (6)

A machine tool machining control method capable of simultaneously and independently machining different machining locations of the same workpiece by at least two or more tool tables provided with a sizing device at a position corresponding to each,
The machine tool sizing control is characterized in that the tool table at the machining location that has reached the target dimension is retracted by a predetermined amount, and the next process is performed simultaneously after the tool table at all machining locations is retracted by a predetermined amount. Method. At least in the first stage before the final process, the tool table at the machining location that has reached the target dimension is retracted by a predetermined amount, and after all the tool tables have retracted by a predetermined amount, the next process is simultaneously performed. The sizing processing control method for a machine tool according to claim 1. 3. The tool table at the machining location that finally reaches the target dimension is configured to simultaneously perform the next process along with other tool tables without retreating by a predetermined amount. The sizing processing control method for the machine tool described. This is a twin-head grinding machine sizing control method that allows two independent grinding wheels to be simultaneously grinded at different machining locations on the same workpiece by means of two grinding wheel platforms equipped with sizing devices at the corresponding positions. And
At least one stage before performing the final spark-out process, the grindstone head at the machining location where the measured value has reached the target dimension is retracted by a predetermined amount, and the spark-out process is simultaneously performed after both grindstone tables are retracted by a predetermined amount. A sizing process control method for a twin head grinder characterized by This is a twin-head grinding machine sizing control method that allows two independent grinding wheels to be simultaneously grinded at different machining locations on the same workpiece by means of two grinding wheel platforms equipped with sizing devices at the corresponding positions. And
At least in one stage before performing the final spark-out process, the grindstone table at the machining location where the measured value has reached the target dimension is retracted by a predetermined amount, and when the other machining location reaches the target value, the retracted grindstone A sizing process control method for a twin-head grinder, wherein a spark-out process is simultaneously performed by both grinding wheel pedestals by advancing the platform by the amount retracted. In a twin-head crankpin grinder that can grind crankpins with different crankshafts simultaneously and independently by two grinding wheel platforms each equipped with a tracking sizing device,
Means for indexing the two wheel heads to the processing position, means for advancing to grind the two wheel heads, and measuring the workpiece at the same time in at least one stage before final grinding on the two wheel heads Means, a means for retreating the grinding wheel base at the machining location where the measurement result first reached the target dimension, and a portion for retreating one of the retreated grinding wheel tables as soon as the measurement result at the other machining location reaches the target dimension. The twin-head crankpin grinder is a sizing grinding control device comprising: means for advancing only by a distance; and means for simultaneously performing a spark-out process by both grinding wheel platforms.

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