JP2004181537A - Run-out removing method of long cylindrical workpiece in numerical control machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining method for automatically, highly accurately and highly efficiently removing rotational run-out of a long cylindrical workpiece. <P>SOLUTION: When removing the rotational run-out of the long cylindrical workpiece W such as a printing roller for centrally supporting both ends on a numerical control cylindrical grinding machine and tearing off a previous outer peripheral surface, a wheel spindle block 25 attached with a measuring instrument 40 for detecting the rotational run-out is indexed in a longitudinal directional position of the workpiece W, and a probe 42 of the measuring instrument 40 is engaged with a surface of the rotating workpiece W, and a feed coordinate position PGm on the tip of a grinding wheel G of the wheel spindle block 25 is fixed so that the measuring instrument 40 engages with the workpiece W in the vicinity of a neutral position Pn of a measuring range. Respective positions Pm and Ps in a tool stand feeding coordinate system are fixed on apparent maximum diameter part and minimum diameter part of the workpiece W in this state. Then, an intermittent cutout traverse grinding cycle is started from the coordinate position Pm of the maximum diameter part or a grinding cycle starting position being a position retreated by a prescribed idle grinding quantity, and the grinding cycle is finished in a position cut out by a prescribed taking margin from the coordinate position Ps of the minimum diameter part. Thus, measurement of the rotational run-out of the workpiece and run-out removing grinding are fully automatically performed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a processing method for automatically removing run-out of a long cylindrical work such as a printing roll with a minimum necessary margin.
[0002]
[Prior art]
The printing rolls used for intaglio or letterpress printing are mounted on a printing press and used for a printing operation, and then regenerated to allow a new and different printing surface to be formed. In the reproduction operation, in the case of an intaglio printing roll, the roll surface is peeled off to remove characters, graphics, and the like that are depressed from the roll surface, and to remove rotational runout of the roll surface. The cause of this rotational runout is mainly that the accuracy of the center holes formed at both ends of the roll is impaired by the use as the roll support holes during the printing operation, and the shape of the center hole itself is distorted or the center hole is distorted by this collapse. This is because the center is substantially deviated from the outer peripheral surface. If the rotational runout is large, not only uneven printing density occurs but also printing becomes impossible in a printing operation in which the roll is reused. For this reason, the used printing roll is processed for subsequent reuse, the surface is peeled off, the printing operation surface is removed, and the run-out is removed.
[0003]
A conventional processing method for regenerating such a printing roll is to remove a used printing roll from a printing press, support both ends of the printing roll at a center on a processing machine such as a lathe, and rotate the roll while rotating the roll. The tool is manually cut by a predetermined amount from the position where the runout in the direction is maximum, and the tool and the roll are relatively moved in the longitudinal direction to traverse the tool so that the tool can contact the entire length of the roll. By repeating such manual cutting and traverse feed many times, the printing surface ahead of the entire length of the roll is removed, and the run-out is also removed.
Also, an attempt of a method of performing automatic processing using numerical control is conceivable. In this attempt, it is conceivable that the maximum run-out amount of the roll is first measured manually, and the initial position of the tool in the cutting direction with respect to the roll is set to a position considerably retracted from the maximum run-out amount. Then, from this initial position, a predetermined amount of infeed is provided at both ends or one end position of the roll, and then a reciprocating cutting feed is provided in the longitudinal direction of the roll, and the infeed and cutting are repeated a predetermined number of times to regenerate the roll surface. An embodiment of the working procedure for processing is conceivable.
[0004]
[Problems to be solved by the invention]
When a cut is manually given in the above-mentioned turning, the operator becomes unequivocally involved in the work of roll regeneration, which is disadvantageous in terms of labor saving.
When an attempt is made to perform automatic machining by using numerical control, the operator does not need to operate or monitor the machining work, which can contribute to labor savings.However, the initial position in the cutting direction of the tool is considerably reduced from the viewpoint of safety. It is necessary to program backward with a margin, and a considerable time loss is required from the start of the numerical control program operation to the actual start of material removal. In addition, the roll regeneration processing can be terminated when the runout of the previous printing surface has been removed from the surface of the roll, and the absolute size at the end is usually not particularly problematic. From the viewpoint of reliable removal of the surface and the run-out, it is necessary to carry out considerable over-cutting.
[0005]
Furthermore, in the conventional processing method using manual tool cutting and numerical control, the run-out measurement of a used roll before printing requires laborious and inaccurate work by an operator.
Instead of the lathe work, it is conceivable to perform the roll regeneration work using a numerically controlled cylindrical grinder, but in the case of using this cylindrical grinder, the initial processing of the work is substantially the same as that described for the numerically controlled lathe. At the end of processing, excessive cutting at the end of processing, and troublesome runout measurement. In particular, in the case where roll regeneration processing is attempted on a cylindrical grinder, it is necessary to set the cutting amount per turn of the grindstone as a tool to be smaller than that of a turning tool, so that material removal in the initial stage of the processing is involved. The time loss due to excessive setting of the empty grinding amount is a further problem.
[0006]
Therefore, a main object of the present invention is to solve these problems and to remove a surface of a long cylindrical work such as a printing roll after use of a certain operation and remove the runout with a minimum allowance. Accordingly, it is an object of the present invention to be able to perform the operation fully automatically and efficiently.
Another object of the present invention is to provide a processing method capable of performing a fully automatic and efficient processing for stripping a surface from a long cylindrical work and removing runout using a numerically controlled cylindrical grinder. .
[0007]
[Means for Solving the Problems and Their Functions]
In order to solve the above-mentioned problem, a run-out processing method according to claim 1, in a numerical control machine tool, engages a probe of a run-out measuring device with a work while rotating the work, and performs run-out during the engagement. Based on the output of the measuring instrument, the positions of the apparent maximum diameter portion and minimum diameter portion in the tool table feed coordinate system due to the rotational runout of the work are stored as the maximum diameter portion position and the minimum diameter portion position, and the tip of the tool is stored. The machining cycle is started after positioning at the maximum diameter portion position or the machining cycle start position, which is the position where the amount of grinding is retracted from this position, and the traverse feed and the cut feed between the tool table and the work support device are repeated. Then, the machining cycle is ended after the tip of the tool is further cut by a predetermined cutting amount from the minimum diameter position.
[0008]
According to this configuration, the apparent maximum diameter portion and the minimum diameter portion due to the rotational runout of the workpiece are stored as the positions of the tool-table feed coordinate system, so that the setting of the tool tip to the machining cycle start position and the end of the machining cycle are completed. The maximum diameter and the minimum diameter are determined based on the positions of the tool table cutting coordinate system. For this reason, the cutting start position can be precisely approached to the maximum diameter portion of the work, and the processing end time can be accurately set to a position where a predetermined allowance is removed based on the minimum diameter portion. As a result, useless idle machining time at the start of machining is reduced, and excessive machining, that is, excessive cutting is prevented.
[0009]
Preferably, as described in claim 2, as the numerically controlled machine tool, a numerically controlled cylindrical grinder that rotatably supports a grindstone on a tool table is used, and a runout measuring device is mounted on the tool table. This movement of the tool base enables positioning with respect to the work, and the maximum diameter and maximum diameter are determined based on the maximum and minimum values of the runout measured by the runout measuring device and the position of the feed coordinate system of the tool base at the time of runout measurement. The position of the tool table feed coordinate system for the small diameter part is now determined.
Since the runout measuring instrument has determined the position of the tool table where the rotational runout of the workpiece can be measured, and obtained the maximum and minimum values of the runout from the runout measuring instrument at this measurement position, the maximum and minimum values of the runout were determined. It is accurately replaced by the position of the cutting coordinate system of the tool table, and the control of the machining cycle of the tool table is performed with high accuracy and reliability.
[0010]
Preferably, as in the swing processing method described in claim 3, the rotational run of the work is performed at a plurality of longitudinal positions including a substantially intermediate position in the longitudinal direction of the work, and the run is measured for each longitudinal position. One of the maximum value and the minimum value indicating the smallest value is selected from the plurality of maximum values and minimum values of the quantity, and the selected one of the maximum value and the minimum value is determined at the time of shake measurement. The apparent maximum diameter position and minimum diameter position of the workpiece are replaced with the position of the tool base feed coordinate system based on the position of the tool base in the feed coordinate system.
The maximum value and the minimum value of the run-out are measured for a plurality of longitudinal positions including a substantially middle position in the longitudinal direction of the work, and the maximum value and the minimum value of these values are obtained, and the maximum diameter portion and the maximum value of the work are obtained. Since the diameter is the minimum diameter, the start position and the end position of the wobble processing cycle of the grindstone are accurately controlled.
[0011]
Furthermore, according to the run-out processing method of the fourth aspect, after the end of the processing cycle, the run-out measuring device checks the rotational run-out of the work.
As a result, the quality of the run-out processing is confirmed on the machine, and if it is determined that the corrective processing is necessary, the corrective processing is quickly and easily performed while maintaining the normal setting of the run-out processing.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a method for removing a long workpiece according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic plan view of a numerically controlled cylindrical grinder for implementing the processing method of the present invention. In FIG. 1, reference numeral 10 denotes a bed, and a table 11 is fixed to a front portion of the bed 10, and a headstock as a work supporting device for rotatably supporting both ends of a work W on the table 11 at a pair of centers. 12 and tailstock 13 are mounted and fixed. The headstock 12 has a rotating face plate 14, and a driving metal 16 fixed to the face plate 14 is engaged with a driven pin 15 screwed into an end face hole of the work W so as to drive the driven pin 15. Thus, when the servomotor 17 fixed to the headstock 12 is driven, the face plate 14 and the work W rotate integrally. The work W has a long cylindrical shape, and in the present embodiment, is a printing roll that is used for printing in an intaglio printing press, removed from the printing press, and processed for reproduction.
[0013]
The slide table 20 is slidably guided in the longitudinal direction of the work W (the direction of the rotational axis O1) along a pair of front and rear guide surfaces 21 formed at the rear of the bed 10. , The workpiece W is traversed on the bed 10 in parallel with the rotation axis O1 of the workpiece W. The slide table 20 guides the grindstone table 25 as a tool table along a pair of left and right guide surfaces 20a formed on its upper surface so as to be able to advance and retreat in a direction crossing the rotation axis O1, more precisely, in a direction orthogonal to the coaxial line. ing. By driving a servo motor 26 attached to the rear end of the slide table 20, the feed screw 27 is rotated, and the grindstone table 25 is advanced and retracted so as to approach or separate from the work W.
[0014]
The grindstone stand 25 rotatably supports a grindstone G as a processing tool around a grindstone axis O2 parallel to the rotation axis of the work at its front left end face side, and the grindstone G is fixed by a drive motor 27 fixed to the right end face side. G can be driven to rotate. In the drawings, reference numerals 29 and 30 denote telescopic cover devices that cover the left and right sides of the slide table 20. Each cover device 29 and 30 has cover members 29a and 30a at its inner end on both sides of the slide table 20. The cover area is fixed and moved integrally therewith so that the cover area expands and contracts with the traverse movement of the slide table 20.
[0015]
On the front surface of the grindstone table 25, a shake measuring device 40 that comes into contact with the work W and detects the shake of the work W is attached. It is possible to move horizontally to the retracted position shown by the broken line.
The above-described servo motors 17, 22 and 26 are provided with encoders 17a, 22a and 26a, respectively, and the output of the encoders 17a, 22a and 26a allows the rotational position of the work W and the Z of the grindstone stand 25 (that is, the grindstone 26). The traverse position in the axis coordinate system and the feed position in the X axis coordinate system can be detected. The servo motors 17, 22, and 26 and the encoders 17a, 22a, and 26a are connected to a computer-controlled numerical controller (hereinafter, referred to as a CNC device) 50 which is generally called a CNC. , And conversely, the position information is fed back to the device 50. Further, the shake measuring device 40 is also connected to the CNC device 50, and can be selectively indexed to a measurement position and a retreat position by a command from the CNC device 50, and an output relating to the shake position is input to the same device 50. Has become.
[0016]
FIG. 2 is an explanatory diagram illustrating a method for detecting a rotational runout of the work W in the runout processing method according to the present invention. The work W in the present embodiment is a roll for intaglio printing, and after being used on a printing machine (not shown), is removed from the printing machine and is center supported on a cylindrical grinding machine. In such a used roll W, characters, graphics, and other information are depressed as concave portions at a depth of, for example, about 40 μm on the outer peripheral surface. In addition, the center hole is deformed by printing ink or other impurities that enter the center hole during printing, and the center of support of the center hole is substantially deviated from the outer peripheral surface of the roll, which causes the roll W to rotate.
[0017]
Typically, as illustrated in FIG. 2, when both center holes are deviated in the same angular phase direction, the roll W has an apparent maximum indicated by a solid line when the phase angle direction is directed to the grindstone G side. When the diameter portion is inserted and the half rotation proceeds from the phase angle, an apparent minimum diameter portion indicated by a two-dot chain line is inserted to the grinding wheel G side. Further, another typical form of rotational runout is a case where both center holes of the roll W are biased in different angular phase directions by a half turn, and in this case, a substantially intermediate position in the longitudinal direction of the roll W has a minimum runout. Both ends are directed to the grindstone G with the apparent maximum diameter part on the opposite side of the diameter direction, respectively, and the minimum diameter part is directed to the grinding stone G on the opposite side of the diameter direction of each maximum diameter part. . In the latter case, on one angle phase, if one end of the roll W has a maximum diameter portion, the other end has a minimum diameter portion. At an angle phase different from that angle phase by half a rotation, one end side of the roll W has a minimum diameter portion. The other end is the maximum diameter portion.
The apparent maximum diameter means that the diameter of the cross-sectional area of the circle formed by the rotation locus of the maximum diameter appears to be larger than the diameter of the actual cross-sectional area.
[0018]
For this reason, when measuring the run-out with the measuring device 40, it is sufficient to measure at least one arbitrary point in the longitudinal direction of the entire length L0 of the roll working surface of the roll W, as shown in FIG. In some cases, it may be necessary to measure the intermediate position L0 / 2 in the longitudinal direction and one or more other positions, preferably a position within a predetermined length L1 from both ends of the roll surface. Since this depends on the characteristics of the roll W, the measurement method may be changed according to the roll to be shake-processed, or the rotational run-out at a plurality of locations may be measured for all rolls.
Note that reference numeral Z0 in the drawing is the origin of the Z-axis coordinate of the cylindrical grinding machine to which the present embodiment is applied, and is defined as a boundary point between the center of the headstock 12 and the end surface of the workpiece W. Starting from the origin Z0, the measurement positions are determined using data such as the total length L0 of the roll W and the predetermined length L1 that have been input to the CNC device 50 in advance.
[0019]
FIG. 3 shows a state of the shake measuring device 40 which measures the rotational shake at each measurement position shown in FIG. The probe 42 suspended from the tip of the measuring rod 41 of the measuring instrument 40 has a maximum diameter position Pm and a minimum diameter surface whose surface of the apparent maximum diameter in the rotating state of the work occupies the feed coordinate system X of the grindstone. Detects the minimum radial position Ps occupying the same coordinate system. In the roll W illustrated in FIG. 3, the actual center Acp is deviated to the right in the figure by the amount of eccentricity e with respect to the normal center Ncp concentric with the outer peripheral surface. Is larger by 2e.
[0020]
Then, in the rotation phase in which the surface of the maximum diameter portion faces the grinding wheel G, the maximum diameter portion position Pm occupying the feed coordinate system X of the grinding wheel head 25 and the rotation phase in which the surface of the minimum diameter portion faces the grinding stone G side. The minimum diameter portion position Ps occupying the same coordinate system is determined by using the encoder 26a of the servo motor 26 with the X axis coordinate position of the grinding wheel head 25 in a state where the measuring device 40 is moved to a position where the apparent maximum diameter and minimum diameter can be measured. , And can be determined based on the coordinate position output and the measurement output of the measuring device 40. Each set of data including the maximum diameter position Pm and the minimum diameter position Ps is obtained for each of a plurality of measurement positions in the Z-axis direction shown in FIG. Then, the largest diameter position Pm having the largest value is selected from the plurality of sets of data, and the position of this largest diameter position Pm or this position is shifted backward by the predetermined safety empty grinding allowance ΔX1. The lowered position PCs is set as the machining cycle start position. In addition, one of the plurality of sets of data is selected as the smallest diameter portion position Ps having the smallest value, and the position PCf that has been cut and fed by a predetermined machining allowance x2 is set as the machining cycle end position.
[0021]
FIG. 4 shows a processing routine of a run-out processing program executed by the CNC device 50. Hereinafter, the procedure of the run-out processing method in the present embodiment will be specifically described according to this processing routine. After supporting the roll which has been used in the intaglio printing machine, that is, the work W, between the headstock 12 and the tailstock 13 of the grinding machine as shown in FIG. 1, a run-out processing command is given to the CNC device 50. Can be The routine in FIG. 4 is started in response to this machining command, and the measurement position designation variable N is set to an initial value "1" in step S1. Next, in step S2, the measuring device 40 is advanced to the measuring position, and the probe 42 is extended forward so that the probe 42 can contact the outer peripheral surface of the work W.
[0022]
In the following step S3, based on N = 1, the servo motor 22 is controlled so that the measuring device 40 is aligned at a position within a predetermined distance L1 from the left end of the processing surface of the workpiece W shown in FIG. This Z-axis control is performed using the following work information and machine information. That is, data L0, L1 and the like are input in advance as work information to the CNC device 50, and the current position of the tip of the grindstone 25 and the tip of the grindstone G in the Z-axis coordinate system and the X-axis coordinate system as mechanical information. , The update in relation to the change of the control position of the grindstone 25 and the diameter reduction by tooling of the grindstone G, and the offset of the probe 42 in the Z-axis direction and the X-axis direction with respect to the front end corner position of the left end surface of the grindstone G. The quantities Mz and Mx (see FIG. 1) are updated and stored in relation to the truing of the grindstone G.
[0023]
Since N = 1, step S5 is executed following step S4, and the X-axis measurement position is determined at the end of the workpiece W (in this embodiment, the position where the measuring device 40 is determined at the position indicated by the solid line in FIG. 2). It is performed in. In this indexing operation, in a state where the servo motor 17 is driven and the workpiece W is rotated, the grindstone head 25 is advanced, and the position of the grindstone head 25 for determining the measurement position of the measuring device 40 is determined by the two-step approach operation. It is. As shown in FIG. 3 as a diagram, the position is determined by a two-step feed of a coarse approach feed Fra with a relatively high speed and a fine approach Ffa with a low speed from a wheel head retreat position (not shown). That is, first, the rough approach feed Fra is performed from the wheel head retreat position, and when the probe 42 comes into contact with the workpiece W and a signal is input to the CNC device 50, the wheel head 25 is retracted at the same speed by a predetermined short distance. Finally, the probe approaches again with the fine approach Ffa, the probe 42 is deviated from the free state, and reaches the neutral point of measurement. At this time, the arrival at the measurement neutral point is detected by the CNC device 50, the indexing feed of the grindstone 25 is stopped, and the deflection measurement position of the grindstone 25 is set. The setting operation of the shake measurement position is preferably performed using a portion where the shake amount is small or hardly present.
[0024]
FIG. 5 is an explanatory view showing details of the measurement range of the measuring device 40. The measuring device 40 always holds the probe 42 at the first measuring end Re1 by a spring mechanism (not shown), and the second measuring end Re2. Up to this point, it can be biased against the repulsion of the spring mechanism. An intermediate position between the two measurement ends Re1 and Re2 is a measurement neutral point Pn. Therefore, when the probe 42 comes into contact with the surface of the workpiece W in the rough approach feed Fra and is deviated from the first measurement end Re1 to the neutral point Pn side, the output change from the measuring device 40 at this moment is captured and the grinding wheel head 25 is moved. The probe 42 retreats by a predetermined short distance, then re-approaches at a low speed in the fine approach Ffa, and is advanced at a low speed until the probe 42 is biased to the neutral point Pn for measurement. The moment when the probe 42 reaches the neutral point Pn is detected by the output from the measuring device 40, and the drive of the servomotor 26 is stopped so as to stop the advance of the grindstone table 25. The stop position of the grindstone table 25 can be read from the encoder 26a, and the tip position of the grindstone G at this stop position is determined as PGm shown in FIG. The measurement neutral point Pn may output a neutral point signal from the measuring device 40. However, when using a type that cannot output the neutral point signal, the output of the measuring device 40 is set inside the CNC device 50. The determination of the neutral point arrival may be performed by comparing with a neutral point threshold value.
[0025]
In this manner, in a state where the grindstone stand 25 is stopped at the position where the probe 42 is biased to the measurement neutral point Pn, step S7 is executed next to rotate the workpiece W. During this time, since the probe 42 is pressed against the surface of the work W by a spring mechanism (not shown), the probe 42 advances and retreats in the X-axis direction along the work surface, and retreats toward the grindstone G side. The minimum diameter output -β approaching is measured. Then, the maximum diameter portion output + α and the minimum diameter portion output -β are respectively added to the sum of the previously captured measurement position grindstone position PGm and the offset distance Mx of the probe 42 with respect to the known grindstone G, whereby the X-axis is obtained. The maximum diameter position Pm and the minimum diameter position Ps in the coordinate system are calculated, and these positions are stored in the memory of the CNC device 50. Next, in step S8, it is determined whether or not the measurement position specifying variable N is the last specified variable 3. In this case, the determination is "No", the variable is incremented in step S9, and the process returns to step S3 again.
[0026]
As a result, the second steps S3 and S5 to S8 are executed, and the maximum radial position Pm and the minimum radial position Ps in the X-axis coordinate system are detected for the work cross section at the intermediate position in the longitudinal direction of the work W shown in FIG. These positions are stored in the memory of the CNC device 50. Further, after the variable N is set to 3 in step S9, the third steps S3, S5 to S8 are executed, and the position of the maximum diameter portion in the X-axis coordinate system with respect to the work section at the right end in the longitudinal direction of the work W is performed. Pm and the minimum diameter portion position Ps are detected, and these positions are stored in the memory of the CNC device 50. Thus, three sets of the maximum diameter portion position Pm and the minimum diameter portion position Ps for each of the cross sections of the left end portion, the middle portion, and the right end portion of the work W are captured as data.
[0027]
When the three sets of the maximum diameter portion position Pm and the minimum diameter portion position Ps are captured in this way, the process proceeds from step S8 to step S10, where the measuring instrument 40 turns and retreats from the solid line measurement position shown in FIG. Retracted to position. In a succeeding step S11, one maximum diameter portion position Pm having the largest value is selected from the data of the three sets of the maximum diameter portion position Pm and the minimum diameter portion position Ps stored in the memory. Then, as shown in FIG. 3, the machining cycle start diameter position PCs is determined by adding the empty grinding allowance ΔX1 for security to the one selected maximum diameter portion position Pm. Further, one minimum diameter position Ps having the smallest value is selected from the data of the three minimum diameter positions Ps, and the machining allowance x2 is subtracted therefrom to determine the machining cycle end diameter position PCf. The deviation between the machining cycle start diameter position PCs and the end diameter position PCf set in this way is divided by the unit depth of cut Δx3 of the machining cycle to obtain the number of divisions of the machining cycle.
[0028]
After this cycle division processing, the process proceeds to step S12, and the machining cycle shown in FIG. 6 is executed. This processing cycle is a grinding method known as an intermittent traverse grinding method, in which a grinding wheel G is cut into the work W at one end or both ends of the rotating work W by a unit cut amount Δx3, and then the work W is rotated in the longitudinal direction of the work W. Is performed to give a traverse feed of When the traverse feed is given after the number of cuts of the grindstone G into the work W reaches the division number, the machining cycle is terminated immediately at the feed end or at the end where the traverse feed is performed in the reverse direction with the cut amount of zero. Then, the grindstone stand 25 retreats to the retreat end position, and the run-out processing ends.
As a result, the printing surface used in the previous intaglio printing operation is peeled off from the surface of the work, and at the same time, the rotational runout is removed, and the work W is regenerated for the next intaglio printing operation.
Briefly, an example of processing is as follows. The depth of the information-imprinted concave portion of the intaglio printing work surface of the work W is 0.04 mm and the run-out is 0.02 to 0.1 mm. The printing operation surface and the run-out were removed by performing a unit cut of a radius of 0.01 mm and a traverse feed about 15 to 17 times.
[0029]
In the present embodiment, after the above-described run-out processing cycle is executed, a run-out confirmation cycle is executed. That is, in step S13, the same processing as steps S3 to S9 is repeatedly performed a plurality of times, and the apparent maximum diameter position Pm and the minimum diameter Pm at the three cross sections at both ends and the center of the work shown in FIG. The part position Ps is measured. Subsequently, in step S14, a maximum shake amount Fmax, which is a deviation between the maximum value of the data of the three maximum radial position Pm and the minimum value of the data of the three minimum radial position Ps, is calculated. In step S16, it is determined whether or not this value exceeds the allowable maximum run-out amount Fref. If it does, an NG report indicating a processing failure is made in step S16, and the routine in FIG.
As a result, the quality of the reworked workpiece that has been subjected to the deflection processing is inspected on the machine, and the defective workpiece is subjected to correction processing to be a non-defective workpiece.
[0030]
(Other embodiments)
In the above-described embodiment, the processing method according to the present invention has been described as being applied to a numerically controlled cylindrical grinding machine. However, other types of machine tools, for example, the processing method according to the present invention may be applied to a numerically controlled lathe. it can.
In the above embodiment, the work is described as a printing roll for intaglio printing. However, the work W may be a roll for letterpress printing, or may be another long cylindrical work other than the printing roll. .
In addition, the measurement of the run-out amount of the work is performed at three positions at both ends and the center of the work. However, the run-out measurement may be performed at more places. In the case where the maximum value of the rotational vibration of the work can be measured at one place in the longitudinal direction of the work due to the characteristics of the printing press or the work, the measurement at a plurality of places is not necessarily required, and such a specific one is not required. The rotational run-out of the work may be measured at a location to determine the maximum run-out.
[0031]
Further, the shake measuring device 40 is not limited to the type shown in FIGS. 1, 3 and 5, and may be used as long as it has a measurement range covering the shake amount of the work W. it can. In particular, the run-out measuring device 40 employs a type mounted on the front surface of the tool base 25, but other types, for example, mounted on the upper surface of the tool base 25, and a grinding stone from above the tool base 25 A type that moves back and forth to a measurement position in front of G can also be adopted.
Further, the form in which the method of the present invention is applied to a grindstone traverse type as a cylindrical grinder has been exemplified, but a table traverse type in which the work table 11 reciprocates in parallel with the work axis O1 without traversing the grindstone head. May be applied. In this case, the runout measuring device 40 can be installed in a place other than the tool table, for example, in a fixed portion such as the bed 10.
Further, the runout measuring device 40 may be provided with a guide feed mechanism of the apparatus itself, which can be indexed along the work axis O1 by the guide mechanism, and which measures the runout of the work at the indexed position. .
[0032]
【The invention's effect】
As described above in detail, according to the present invention, the rotational runout of the work is automatically measured, and the apparent maximum diameter portion and the minimum diameter portion due to the rotational runout of the work are stored as the positions of the tool-table feed coordinate system. The setting of the tool tip to the machining cycle start position and the end of the machining cycle can be performed accurately and quickly without involving the human error caused by manual operation based on the position of the tool table feed coordinate system of the largest diameter part and the smallest diameter part. Is determined automatically. For this reason, the cutting start position can be precisely approached to the maximum diameter portion of the work, and the processing can be reliably finished at a position cut by a predetermined allowance from the coordinate position of the minimum diameter portion, which contributes to labor saving of the run-out processing operation. In addition, practical effects such as shortening of machining time and prevention of excessive machining, that is, prevention of excessive excessive cutting, can be obtained.
[0033]
According to the second aspect of the present invention, the method of the present invention can be carried out on a cylindrical grinder, and a runout measuring device can be mounted on a tool table supporting a grindstone of the cylindrical grinder to measure rotational runout of a work. Since the position of the tool stand is determined and the maximum and minimum values of the run-out amount are obtained from the run-out measuring device at this measurement position, the maximum and minimum values of the run-out are accurately set to the position of the feed coordinate system of the tool base. In other words, the control of the machining cycle of the tool table can be performed with high accuracy and certainty, and a highly accurate and efficient run-out process by grinding can be realized.
[0034]
According to the third aspect of the present invention, the maximum value and the minimum value of the runout are measured for a plurality of longitudinal positions including a substantially middle position in the longitudinal direction of the workpiece, and the maximum value and the minimum value among these values are measured. Since the values are obtained and set as the maximum diameter portion and the minimum diameter portion of the workpiece, the start position and the end position of the wobble processing cycle of the grindstone can be controlled with higher accuracy.
Furthermore, according to the invention as set forth in claim 4, after the machining cycle is completed, the run-out detector checks the rotational run-out of the work, so that the quality of the run-out process can be checked on the machine, and the correction process can be performed. If necessary, the correction processing can be performed quickly and easily in the setting state of the regular run-out processing.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a numerically controlled cylindrical grinder that implements a method of processing a long cylindrical workpiece according to the present invention.
FIG. 2 is an explanatory diagram for explaining a measurement position of rotational shake.
FIG. 3 is an explanatory diagram illustrating a relationship between an engagement position of a measuring instrument probe and a position on an X-axis coordinate system at the time of shake measurement.
FIG. 4 is a flowchart showing a program routine executed by the CNC apparatus of the numerically controlled cylindrical grinding machine of FIG. 1 to carry out the run-out processing method according to the present invention.
FIG. 5 is an explanatory diagram for explaining a relationship between a measurement range of the measuring instrument probe shown in FIG. 3 and a position on an X-axis coordinate system.
FIG. 6 is an explanatory diagram for explaining the movement of the grindstone G in the run-out grinding cycle.
[Explanation of symbols]
W: long cylindrical workpiece, 12: headstock, 13: tailstock, G: grinding wheel (tool), 25: grinding wheel table (tool table), O1: rotation axis of the workpiece, 20: slide table, 17, 22 , 26: servo motor, 17a, 22a, 26a: encoder, 50: CNC device, 40: measuring instrument, 42: probe, Pm: maximum diameter position, Ps: minimum diameter position, Δx1: empty grinding amount, PCs: Machining cycle start position, x2: Depth of cut (stock), PCf: Machining cycle end position

Claims (4)

Both ends of the long cylindrical work are rotatably supported by a work supporting device, and a tool table on which a tool for processing is mounted is provided so as to be able to advance and retreat in a direction crossing the rotation axis of the work, and the tool table and the A work support device capable of relatively traversing the work in the axial direction of the work, providing a run-out measuring device capable of measuring a run-out amount of the work by bringing a probe into contact with the outer peripheral surface of the work, In a numerically controlled machine tool capable of numerically controlling the feed and the traverse feed, a first step of engaging the probe of the runout measuring device with the work while rotating the work, and measuring the runout during the engagement. Based on the output of the tool, the positions of the apparent maximum diameter portion and the minimum diameter portion in the tool table feed coordinate system due to the rotational runout of the workpiece are maximized. A second step of storing as a part position and a minimum diameter part position, and the tool table so as to position the tip of the tool to the maximum diameter part position or a machining cycle start position which is a position retracted by an idle grinding amount from this position. A third step of advancing, repeatedly executing a traverse feed and a cut feed between the tool base and the work support device after starting the processing cycle after advancing the tool base to the processing cycle start position, A fourth step of ending the machining cycle after the tip of the tool is further cut by a predetermined allowance from the minimum diameter position. The numerically controlled machine tool is a numerically controlled cylindrical grinding machine configured to grind the work with the grindstone by rotatably supporting a grindstone as the tool on the tool table, wherein the runout measuring device is mounted on the tool table. The tool is mounted and can be positioned with respect to the work by moving the tool table. The second step includes a maximum value and a minimum value of a run-out amount measured by the run-out measuring device and a cut of the tool base at the time of run-out measurement. The method according to claim 1, wherein the position of the maximum diameter portion and the position of the minimum diameter portion are determined based on a position in a coordinate system. The first step comprises selectively engaging a probe of the deflection measuring device at a substantially intermediate position in the longitudinal direction of the workpiece and at one or more other positions, and the second step includes One maximum value indicating the largest value and one minimum value indicating the smallest value among a plurality of maximum values and minimum values of the shake amount measured by the shake measurement device at each position in the longitudinal direction of the work. And determining the maximum diameter portion position and the minimum diameter portion position based on the selected one of the maximum value and the minimum value and the position of the feed coordinate system of the grinding stone at the time of runout measurement. Item 3. A runout processing method for a long cylindrical workpiece according to Item 2. 4. The method according to claim 1, further comprising: after the fourth step, performing a checking step of engaging a probe of the shake measuring device with the workpiece and checking an output of the shake measuring device detected by the probe. 5. A method for processing a long cylindrical work, as described in Crab.

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