JP6590711B2 - Manufacturing system and manufacturing method - Google Patents

Description

  The present invention relates to a manufacturing system and a manufacturing method having a cutting device and a grinding device.

The grinding time of the grinding device changes according to the amount of grinding allowance, and the grinding time increases as the amount of grinding allowance increases.
The grinding allowance requires a certain amount (= workpiece deflection + surface roughness) in order to remove workpiece deflection and surface roughness and obtain a predetermined processing dimension. If the grinding allowance is small, the workpiece run-out and surface roughness cannot be removed, resulting in failure.
The grinding allowance is determined by a cutting process that is a pre-process of the grinding process. Therefore, in order to shorten the grinding time, it is effective to maintain the grinding allowance at a constant amount (= workpiece deflection + surface roughness) in the cutting process. There are several technical examples for maintaining the required accuracy in the cutting process.
Conventional cutting machines have sampling means and storage means for machining data, and perform adaptive control to measure the machining diameter of the workpiece in-process with the contact in contact with the inner peripheral surface of the workpiece and output the optimum machining conditions. There is something to do. (For example, patent document 1).

JP-A-6-335843 (pages 2 and 3, FIG. 1)

The above-described conventional cutting apparatus has the following problems.
(1) In the cutting apparatus, the workpiece is gripped on one side, and there is an inclination. Therefore, when the vibration is measured by the cutting apparatus, the vibration is measured by combining two of the following: (a) the vibration due to the inclination of the workpiece with respect to the reference axis and (b) the vibration of the inclination due to the one-side grip of the workpiece. In calculating the target value of the grinding allowance, only the deflection (a) is necessary, and the deflection (b) is unnecessary.
(2) In the cutting apparatus, there is a difference between the target value of the outer diameter and the actual measured value of the outer diameter due to the influence of tool wear and thermal expansion of the equipment.
(3) The workpiece outer diameter and runout after the cutting process vary from workpiece to workpiece. When setting the target value for grinding allowance, a setting that takes this variation into account is necessary.

  The present invention has been made to solve the above-described problems. Grinding to be set in a cutting device for cutting based on the measurement result of the workpiece outer diameter and runout measured by the grinding device. It is an object of the present invention to obtain a manufacturing system and a manufacturing method for calculating a target value for machining allowance.

In the manufacturing system according to the present invention, a cutting device for cutting a workpiece based on a preset setting value for cutting, and a workpiece after cutting by the cutting device is set to a preset setting value for grinding. based, grinding grinding device, after which the tool of the grinding device quickly began advance, before the tool contacts the workpiece, measuring unit for measuring the wobbling caused by the tilt as to the reference axis of the outer diameter and the work of the workpiece, the A storage unit that stores the outer diameter and runout value measured by the measurement unit for each workpiece, and based on the average value and variation index of the runout of a predetermined number of workpieces stored in this storage unit, should be left in the cutting process A grinding allowance target value calculation unit that calculates a target value of the grinding allowance and transmits it to the cutting device is provided. The cutting device has an index of the grinding allowance transmitted from the grinding allowance target value calculation unit. Change the cutting setting values based on the value, based on cutting machining set value of this change, and performs cutting.

According to the present invention, a cutting device that cuts a workpiece based on a preset setting value for cutting, and a workpiece after cutting by the cutting device is ground based on a preset setting value for grinding. Grinding device to be processed, measuring unit that measures runout due to the workpiece's outer diameter and tilt relative to the reference axis before the tool contacts the workpiece after the tool of this grinding device has started rapid advance , A storage unit that stores the measured outer diameter and run-out value for each workpiece, and a grinding allowance to be left in the cutting process based on an average value and variation index of a predetermined number of workpieces stored in the storage unit. A grinding allowance target value calculation unit that calculates a target value and transmits it to the cutting device is provided. The cutting device performs a cutting process based on the grinding allowance target value transmitted from the grinding allowance target value calculation unit. Change the set value, on the basis of the cutting machining set value of this change, since the cutting, the grinding allowance can be reduced, it is possible to shorten the time required for grinding.

It is a block diagram which shows the manufacturing system by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the manufacturing system by Embodiment 1 of this invention. It is a detailed block diagram which shows the manufacturing system by Embodiment 1 of this invention. It is a flowchart which shows the grinding allowance target value calculation process of the manufacturing system by Embodiment 1 of this invention. It is a flowchart which shows the target value calculation process of the empty grinding start position of the manufacturing system by Embodiment 1 of this invention. It is a block diagram which shows the manufacturing system by Embodiment 2 of this invention. It is a figure which shows the statistical analysis range designation | designated screen of the manufacturing system by Embodiment 3 of this invention. It is a figure which shows the statistical analysis range designation | designated screen of the manufacturing system by Embodiment 4 of this invention.

Embodiment 1 FIG.
1 is a block diagram showing a manufacturing system according to Embodiment 1 of the present invention.
In FIG. 1, the manufacturing system is configured as follows.
The lathe No. 1 and lathe No. 2 which are cutting devices each cut the workpiece based on the set values for cutting. The grinding machine 3 as a grinding device grinds the workpiece based on the set value for grinding. The sizing device 4 of the grinding machine 3 measures the displacement amount of the workpiece.
The outer diameter / runout calculation unit 5 (measurement unit) calculates the outer diameter / runout after the cutting process based on the amount of displacement of the workpiece. The outer diameter / runout recording unit 6 accumulates the calculated outer diameter / runout of the workpiece. The grinding allowance target value calculation unit 7 calculates a target value for the grinding allowance set in the cutting process. The display unit 8 displays the data accumulated in the outer diameter / runout recording unit 6.
It should be noted that the outer diameter / runout calculation unit 5, the outer diameter / runout recording unit 6, the grinding allowance target value calculation unit 7 and the display unit 8 may be formed on a computer.
Moreover, although the manufacturing system of FIG. 1 uses two cutting devices, any number may be used as long as it is one or more.

FIG. 3 is a detailed configuration diagram showing the manufacturing system according to the first embodiment of the present invention.
In FIG. 3, 4 to 8 are the same as those in FIG.
The grinding apparatus of FIG. 3 is configured as follows.
The pair of measuring elements 12a and 12b are in contact with the outer diameter surface of the work 11 and are opposed to each other. The displacements G1 and G2 measured by the measuring elements 12a and 12b are amplified from the sizing device 4 by the amplifier 13, converted from analog to digital by the A / D converter 14, and sent to the grinding control calculation unit 15.
The grinding control calculation unit 15 performs various types of plunge grinding control based on the value of G1 + G2. The CNC control device 16 transmits the grindstone feed speed to the grindstone table feed device 19 and the spindle rotational speed to the grindstone drive device 18 according to various controls. The CNC input unit 17 can input various control parameters for plunge grinding, and is transmitted from the CNC input unit 17 to the CNC control device 16. The grindstone table 10 is loaded with the grindstone 9 and is moved by the grindstone table feeding device 19. The displacement recording unit 20 samples and records the values of the displacements G1 and G2.
The cutting device includes a CNC input unit 21 for inputting various control parameters for cutting and a CNC control device 22 for controlling cutting.

Next, the operation will be described.
In FIG. 1, the workpiece is processed in the order of lathe No. 1, lathe No. 2, and grinding machine 3. In the grinding machine 3, the outer diameter / runout of the workpiece is calculated by the outer diameter / runout calculation unit 5 and accumulated in the outer diameter / runout recording unit 6. A grinding allowance target value calculation unit 7 calculates a grinding allowance target value from the outer diameter and runout of the workpiece accumulated in the outer diameter and runout recording unit 6, and inputs them to the lathe No. 1 machine and the lathe No. 2 machine 2.

The machining performed by this manufacturing system is to complete a shaft part by turning a lathe workpiece with a lathe No. 1 and a lathe No. 2 and grinding with a grinder 3.
Here, in the lathe No. 1 machine, one end of the shaft-like workpiece is gripped and rotated, and turning is performed with a cutter as a tool.
After the machining in lathe No. 1 is completed, in lathe No. 2 the other end different from that held in lathe No. 1 is gripped and rotated, and the lathe 1 out of the shaft-like work is cut by a cutter as a tool. The other part different from that machined by the machine 1 is turned.
In the above, the case where the lathe No. 1 and lathe No. 2 and the two lathes are used for machining has been described, but both sides of the shaft-like workpiece may be machined by changing the gripping portion with the same lathe.

Next, the shaft-shaped workpiece machined by the lathe moves to the grinding machine 3 and is gripped by the grinding machine 3. The outer diameter and runout of the shaft-like workpiece are measured in the gripped state. The measured outer diameter and runout are accumulated in the outer diameter / runout recording unit 6 for each axial workpiece.
Next, the grinding machine 3 is ground as set by the grinding machine 3, and when the grinding is completed, the shaft part is completed.
These operations are performed on a predetermined number of shaft-shaped workpieces, and the outer diameter and runout are measured for each shaft-shaped workpiece, and a predetermined number of outer diameters and runout information are accumulated in the outer diameter / runout recording unit 6. .

When a predetermined number of outer diameter and runout information are accumulated, the grinding allowance target value calculation unit 7 statistically processes the information to obtain a standard deviation (an index related to variation) and the like, and based on the machining results, the grinding allowance is calculated. Decide the target value and set the machining setting value such as cutting in turning. The determined turning setting value is transmitted to the lathe, specifically, lathe No. 1 and lathe No. 2 and set.
Then, the lathe No. 1 and the lathe No. 2 perform the turning process in accordance with the newly set machining set value from the machining of the next axial workpiece, and the newly set grinding allowance target for the grinding machine 3 A shaft component by value arrives, and the grinding machine 3 performs grinding on this shaft component.
The measurement of the outer diameter and runout by the grinding machine 3 may be continuously performed after this, and the result may be accumulated in the outer diameter / runout recording unit 6. In this case, further, a predetermined number of shaft-shaped workpieces are machined. Based on the results of the new machining settings, a grinding allowance target value is further set, and machining setting values such as incisions in lathe machining are determined. You may transmit to the 1st machine 1 and the lathe No. 2 machine 2, and you may process by the further changed process setting.

Next, it will be described that the manufacturing efficiency is improved by the present manufacturing system.
In lathe processing, since one side of the axial workpiece is gripped, the central axis of the axial workpiece is often inclined with respect to the reference axis of the machine tool. As a result, (a) shake due to the inclination of the workpiece with respect to the reference axis occurs.
After gripping one of the shaft-like workpieces with lathe No. 1 and then holding the other of the shaft-like workpieces with lathe No. 2 machine, strictly, the central axes of both ends of the turned shaft parts do not coincide with each other There are many. This is (b) a tilting shake caused by one-side gripping of the shaft-like workpiece.

When turning and then grinding, in addition to (a) deflection due to the tilt of the workpiece with respect to the reference axis, and (b) deflection due to the tilt due to one-side grip of the shaft-shaped workpiece, in lathe machining, tool wear and equipment Due to the effect of thermal expansion, there is a difference between the target value of the outer diameter and the actual measured value of the outer diameter.
In the present manufacturing system, a processing set value such as incision in lathe processing is determined in consideration of the difference in outer diameter and runout, and further considering a grinding allowance in the grinding machine 3.
Conventionally, taking into account differences due to differences in lots of shaft workpieces, tool wear levels, equipment environments, etc., cutting with lathe processing to leave as much grinding allowance as possible on the safe side of shaft parts Equal processing set value was decided.
In this production system, the outer diameter and runout of the shaft-shaped workpiece are measured with a grinding machine, and based on the measurement results, the target value of the grinding allowance set in the cutting machine is calculated. A predetermined number of turning results of the workpiece are stored in the outer diameter / runout recording unit 6, and the grinding allowance target value calculation unit 7 uses the information of the outer diameter / runout recording unit 6 to conventionally grind the safety side. In order to reduce machining allowance, machining setting values such as cutting in turning are set to improve the overall machining efficiency.

Next, the operation of the manufacturing system will be described with reference to FIG.
Lathe No. 1 enters the workpiece, cuts and takes out, and then Lathe No. 2 enters the workpiece, cuts and takes out.
The operator inputs the number m of reviewing intervals for grinding allowance (m is an integer of 2 or more) before the workpiece is input (step 200). Thereafter, the workpiece is loaded, processed, and taken out in the order of lathe No. 1, lathe No. 2, and grinding machine 3.
In grinding by the grinding machine 3, the outer diameter and runout of the workpiece are calculated and accumulated. When the grinding process in the grinder 3 is completed and the workpiece is dispensed, the machining completion of the workpiece is counted, and if the number of completed machining is n or more, the grinding allowance is reconsidered.
Hereinafter, description will be made assuming that the number m of the review interval of the grinding allowance is 100.

In step 201 in FIG. 2, a work is put into the lathe No. 1 machine 1. Here, the workpiece is the same as what has been called a shaft-shaped workpiece in the above description. Here, the workpiece is a material that has not been turned.
In step 202 (cutting process), the lathe No. 1 machine 1 performs cutting (turning). Here, it is assumed that a shaft part is machined, and lathe No. 1 1 grips one end of the shaft-like workpiece with the chuck of lathe No. 1 1 and rotates this to rotate a tool post in the form of a tool post (tool). Cut into, feed, and turn. At this time, rotation, cutting, and feeding are programmed in the lathe No. 1 machine, and the lathe No. 1 machine 1 processes according to this. The incision is set so that a grinding allowance for grinding in a later process remains.
In step 203, the shaft part (workpiece) turned by the lathe No. 1 is taken out.

In step 204, the shaft parts machined by the lathe No. 1 machine 1 are put into the lathe No. 2 machine 2.
In step 205 (cutting process), the lathe No. 2 machine 2 cuts (turns) the shaft component input in step 204. Here again, assuming that the shaft parts are to be machined, Lathe No. 2 machine 2 grips one end (one end machined by Lathe No. 1 machine 1) with the chuck of Lathe No. 2 machine 2 which is not machining the axial workpiece. Then, this is rotated, cut into a tool post-like tool (tool), and fed to be turned. At this time, rotation, cutting, and feeding are programmed in the lathe No. 2 machine 2, and the lathe No. 2 machine 2 processes according to this. The incision is set so that a grinding allowance for grinding in the next process remains.
In step 206, the shaft part (workpiece) turned by the lathe No. 2 machine 2 is taken out.

In step 207, the shaft part (work) processed in step 206 is put into the grinding machine 3.
In step 208, the grinding machine 3 grips the inserted shaft component, measures (calculates) the outer diameter / runout of the shaft component (measurement process), and records the result in the outer diameter / runout recording unit 6 ( Memory step).
In step 209 (grinding step), the grinding machine 3 performs grinding with the shaft part gripped in step 208. The grinding machine 3 rotates the shaft component in accordance with a preprogrammed command value (grinding setting value) and performs grinding while applying feed. In this case, grinding is often performed after moving the tool at high speed by blank grinding. Grinding time can be reduced because it moves faster than during grinding.

In step 210, it is determined whether or not the number of workpieces that have been processed is equal to or greater than the number m of the grinding allowance review interval. If it is less, the process returns to Step 201, and if it is above, the process proceeds to Step 211.
In step 211 (grinding allowance target value calculating step), the grinding allowance target value calculating unit 7 statistically processes the runout value recorded in the outer diameter / runout recording unit 6 to obtain a grinding allowance target value.
In step 212, the grinding allowance target value obtained in step 211 is transmitted to lathe No. 1 and lathe No. 2 by communication.
In step 213, the number of workpieces that have been processed is reset to zero.
Here, lathe No. 1 and lathe No. 2 obtain a machining setting value (setting value for cutting) such as cutting in the lathe machining from the grinding allowance target value and reflect it in the machining program. Thereafter, the process returns to step 201, and machining is performed with the newly set machining set value (machining program).
In FIG. 2, the grinding of step 209 is completed, and after the condition determination of step 210, the next workpiece is input to step 201, but steps 201 to 209 are the product flow. Since the information flow and the flow in step 212 are different, after step 203 is completed, step 201 can be input to the empty lathe No. 1. In this case, the signal transmitted in step 210 or step 212 needs to be transmitted when the lathe work is input.

Next, the manufacturing system including the grinding apparatus will be described in more detail with reference to FIG.
A sizing device 4 and measuring elements 12a and 12b are attached to the grinding device. The in-process gauge sandwiches the outer diameter of the rotating workpiece 11 between the two measuring elements 12a and 12b during the plunge grinding cycle, and measures the displacement amounts G1 and G2 of the measuring elements 12a and 12b. The outer diameter and runout of the workpiece 11 can be calculated from the displacement amounts G1 and G2 by the following formula.
Outer diameter = G1 + G2 + Target diameter Runout = Maximum value of G1 during one rotation-1Minimum value of G1 during one rotation In the grinding machine, the outer diameter / runout of the work 11 after cutting in lathe No. 1 and lathe No. 2 In order to measure, it is necessary to measure before the workpiece | work 11 and the grindstone of a grinding device contact.

One cycle of plunge grinding in the grinding machine is (1) rapid grinding wheel advance, (2) idle grinding, (3) rough grinding, (4) rough grinding dwell, (5) precision grinding, (6) spark out, (7 ) Consists of 7 steps of grinding wheel rapid retreat. Of these seven steps, the rapid advancement of the grindstone and the idle grinding are steps in which the workpiece 11 and the grindstone 9 of the grinding apparatus are not in contact.
Therefore, in the present invention, the displacements G1 and G2 of the measuring elements 12a and 12b are sampled between the start of rapid advancement of the grindstone and rough grinding to calculate the outer diameter and runout of the workpiece 11 before grinding.
The measuring elements 12a and 12b are in contact with the outer diameter surface of the work 11 and face each other. The displacements G1 and G2 measured by the measuring elements 12a and 12b are sent to the grinding control calculation unit 15 through the sizing device 4, the amplifier 13, and the A / D converter 14.

The grinding control calculation unit 15 performs various types of plunge grinding control based on the value of G1 + G2. The CNC control device 16 transmits the grindstone feed speed to the grindstone table feed device 19 and the spindle rotational speed to the grindstone drive device 18 according to various controls.
Further, various control parameters for plunge grinding can be input at the CNC input unit 17 and transmitted from the CNC input unit 17 to the CNC control device 16.

At the start of plunge grinding, the CNC controller 16 outputs a grindstone rapid advance start signal. Upon receipt of the grindstone rapid advance start signal output, the displacement amount recording unit 20 samples the values of the displacement amounts G1 and G2. When the grindstone 9 reaches the empty grinding start position, the CNC control device 16 outputs a grindstone rapid completion signal. In response to the output of the grindstone rapid completion signal, the displacement amount recording unit 20 delivers the sampling results of the displacement amounts G1 and G2 to the outer diameter / runout calculation unit 5.
The outer diameter / run-out calculation unit 5 calculates the outer diameter of the workpiece 11 before grinding from the sampling results of the displacement amounts G1 and G2, and stores it in the outer diameter / run-out recording unit 6. Further, the outer diameter / runout calculation unit 5 calculates the runout of the workpiece 11 before grinding from the sampling results of the displacement amounts G1 and G2, and stores it in the outer diameter / runout recording unit 6.

  The grinding allowance target value calculation unit 7 acquires the outer diameter / runout of the workpiece 11 stored in the outer diameter / runout recording unit 6 and averages the past 100 outer diameters / runouts for each plunge position (hereinafter, The outer diameter average and runout average) and the standard deviation of the outer diameter and runout for the past 100 cases (hereinafter referred to as outer diameter standard deviation and runout standard deviation) are calculated, and the recommended value for the grinding allowance is calculated.

  In the above description, the past 100 cases have been described. However, the present invention is not limited to this. The number of works may be set according to the number of works, and the number of cases may be given from the outside.

The target value of the grinding allowance set in the cutting process may be calculated as follows.
The operator inputs the number n of data to be used for reviewing the grinding allowance before inputting the workpiece. The manufacturing system calculates an average value of run-out for the past n cases and 3σ (σ: standard deviation) of run-out at the timing of machining m pieces, and calculates a target value of grinding allowance set in the cutting process.
Target value of grinding allowance to be set in the cutting process = Average value of runout for the past n cases + 3σ of runout for the past n cases + Theoretical surface roughness Theoretical surface roughness is a constant that can be calculated according to the cutting conditions Yes, the operator inputs in advance when the manufacturing system is executed. The calculated recommended value for the grinding allowance of the cutting device is set in the CNC input unit 21 of the cutting device for each plunge position.

Next, the processing in step 208 of FIG. 2 by the outer diameter / runout calculation unit 5 will be described in detail with reference to FIG.
Step 401 starts the rapid advance of the grinding wheel 3.
In step 402, the grinding machine 3 starts sampling the workpiece displacements G1 and G2 by the measuring elements 12a and 12b.
In step 403, the grinding machine 3 starts blank grinding.
In step 404, the maximum value of G1 + G2 within the sampling interval of the displacement amounts G1 and G2 measured in step 402 is obtained as an outer diameter, and a value obtained by subtracting the minimum value of the displacement amount G1 from the maximum value of the displacement amount G1 is obtained as a shake. .
In step 405, the outer diameter and shake determined in step 404 are recorded in the outer diameter / shake recording unit 6.
Steps 401 to 405 are performed when a workpiece is loaded into the grinding machine 3, and the outer diameter and runout are calculated for each workpiece and recorded in the outer diameter / runout recording unit 6.

Next, the processing of steps 211 and 212 in FIG. 2 by the grinding allowance target value calculator 7 will be described in detail with reference to FIG.
In step 501, the past n vibrations recorded in the outer diameter / vibration recording unit 6 are extracted. For example, n may be 100. Here, the number is 100, but the number is not limited to 100, and may be set from the outside.
In step 502, the average and standard deviation of the past n shakes extracted in step 501 are obtained.
In step 503, a value obtained by adding the average of the shakes obtained in step 502, the shake standard deviation * 6, and the theoretical surface roughness is obtained as a grinding allowance target value.
Also,
Grinding allowance target value in the cutting process may be the average of vibrations of the past n cases + 3σ of vibrations of the past n cases + theoretical surface roughness.
In step 504, the grinding allowance target value obtained in step 503 is transmitted to the lathe No. 1 machine 1 and the lathe No. 2 machine 2. Lathe No. 1 and Lathe No. 2 machine 2 performs processing by converting the grinding allowance target value sent to the machining set value. At this time, the machining program or the command value is changed.

According to the first embodiment, the present manufacturing system records the outer diameter and runout measured before grinding processing for each shaft component in a state where the shaft component is gripped by the grinding machine 3, and performs turning and turning on a predetermined number. After grinding, the grinding allowance target value is obtained from the recorded outer diameter and average deviation and standard deviation, and based on this, the setting value for turning is changed. Considering the machining conditions to be used, the grinding allowance was set with a large allowance, but the grinding allowance can be set by looking at the actual machining results. Therefore, the manufacturing efficiency can be improved.
Also, since the outer diameter and runout are measured with the shaft part held by the grinding machine 3 and immediately before grinding, it is possible to measure the outer diameter and runout that actually affect the grinding process. After processing is finished, the accuracy is higher than measuring with a lathe held.
In addition, after turning and grinding a predetermined number, a grinding allowance target value is set based on a predetermined number of outer diameters, average runout, and standard deviation. be able to.

Embodiment 2. FIG.
In the plunge grinding cycle, the grinding wheel feed speed during idle grinding is slower than during rapid grinding wheel advance. Therefore, in order to shorten the grinding time, it is necessary to bring the start position of blank grinding closer to the contact start position of the grindstone and the workpiece.
However, the start position of blank grinding must be a position farther from the contact start position of the grindstone and the workpiece. This is to prevent the workpiece and the grindstone from contacting at high speed.
Therefore, it is necessary to consider the variation in the outer diameter and runout for each workpiece in the starting position of the idle grinding. However, since there is no means to grasp the variation in the outer diameter and runout of the workpiece, conventionally, the start position of blank grinding is left to the operator's sense, and the blank grinding start position is set at a far distance, and productivity is increased. Has led to a decline.
In order to cope with this, the second embodiment calculates the start position of idle grinding.

FIG. 6 is a block diagram showing a manufacturing system according to Embodiment 2 of the present invention.
In FIG. 6, 1 to 8 are the same as those in FIG. In FIG. 6, a blank grinding start position calculation unit 23 that calculates the blank grinding start position using the outer diameter and deflection for each workpiece recorded in the outer diameter / running recording unit 6 is provided. The blank grinding start position calculator 23 may be formed on a computer on which the grinding allowance target value calculator 7 is formed.

  The calculation of the target value of the blank grinding start position by the blank grinding start position calculation unit 23 according to the second embodiment is performed by calculating the workpiece outer diameter / runout accumulated in the outer diameter / runout recording unit 6 in the first embodiment. Originally, it can be performed by calculating the average value and standard deviation of the outer diameter and runout of the workpiece in the same processing flow as in FIG. The difference from FIG. 5 is that the average value and standard deviation of the outer diameter of the workpiece are used.

Hereinafter, the calculation of the target value of the start position of the blank grinding according to the second embodiment will be described.
The outer diameter and runout of the workpiece accumulated in the first embodiment are extracted for n cases. Then, the average value of the outer diameter for the past n cases, the average value of the runout for the past n cases, the 3σ of the outer diameter for the past n cases, and the 3σ of the runout for the past n cases are calculated, and the target of the empty grinding start position Calculate the value.
The target value of the blank grinding start position is calculated by the following formula.
Target value of blank grinding start position = average value of outer diameter for the past n cases + average value of runout for the past n cases + 3σ of outer diameter for the past n cases + 3σ of runout for the past n cases + theoretical surface roughness The target value of the blank grinding start position calculated by this equation is automatically input to the grinding device through the CNC control device 16 of the grinding device. It is also possible to display the target value for starting blank grinding on the display unit 8 and input it after confirmation by the operator.

  According to the second embodiment, with this configuration, even when the outer diameter and runout of the workpiece vary within the range of + 3σ, the minimum value at which the workpiece and the grindstone do not contact at high speed can be set as the empty grinding start position. , Productivity can be improved.

Embodiment 3 FIG.
In Embodiments 1 and 2, when calculating the grinding allowance target value and the target value of the start position of the idle grinding, 3σ is used as a value that takes into account variations in the outer diameter and runout. Can be arbitrarily selected. Embodiment 3 relates to this, and will be described below.

For example, it is also possible to display a distribution map of fluctuations for the past n cases on the display unit 8 and select a variation consideration range from the distribution map.
FIG. 7 is a diagram showing a statistical analysis range designation screen of the manufacturing system according to the third embodiment of the present invention.
In the distribution diagram of FIG. 7, the horizontal axis represents the outer diameter or the magnitude of the shake, and the vertical axis represents the frequency.
When the operator selects what value on the horizontal axis is to be entered, a variation range is set, and based on this value (an index related to variation), the value of 3σ in the first embodiment is changed to a grinding allowance. It is possible to calculate the target value and the target value of the blank grinding start position.

  According to the third embodiment, it is possible to control the grinding allowance target value and the target value of the blank grinding start position, and there is an effect that it is possible to set a target value in consideration of machining time including grinding and damage due to damage.

Embodiment 4 FIG.
In the first embodiment, the number of intervals n (n is an integer equal to or greater than 0) for executing the processing for reviewing the grinding allowance target value set in the cutting process is specified, but this is executed at an arbitrary timing and in an arbitrary range. be able to. Embodiment 4 relates to this.
In the fourth embodiment, for example, as shown in FIG. 8, past shake values are displayed in time series, and an outer diameter and a shake extraction range can be selected.

FIG. 8 is a diagram showing a statistical analysis range designation screen of the manufacturing system according to the fourth embodiment of the present invention, which is displayed on the display unit 8.
In FIG. 8, the vertical axis indicates the outer diameter or runout, and the horizontal axis indicates the measurement time order (time series) or data order (right is the latest data). The thick vertical line in the graph indicates the range of statistical analysis.

Next, with reference to FIG. 8, when obtaining the grinding allowance target value in step 211 of FIG. 2 of the grinding allowance target value calculation unit 7, a range of measurement data to be statistically analyzed (average and standard deviation is obtained) is set. This will be explained.
The operator can select a range for statistical analysis from the data arranged in time series while viewing the graph of FIG. 8 on the display screen. In particular, when the lot changes or when the tool is changed, the outer diameter or runout may change.
In the example of FIG. 8, the outer diameter decreases on the right side from the center of the screen and variation is small. Here, the grinding allowance target value calculation unit 7 can select from where in the time series to where the statistical analysis range is targeted by an input device such as a mouse or key.
In this example, from the center right side of the screen to a part on the right side is selected so that the corresponding shake data is a target for statistical analysis.

  According to the fourth embodiment, by providing the interface unit with the operator as described above, the configuration is made such that the measurement data after the time when the lot is changed and the time when the tool is changed is calculated as an object. The grinding allowance target value can be changed based on the data from the time point when the change occurs, and the accuracy can be further improved.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 Lathe No. 1, 2 Lathe No. 2, 3 Grinding machine, 4 Sizing device, 5 Outer diameter / runout calculation section, 6 Outer diameter / runout recording section, 7 Grinding allowance target value calculation section, 8 Display section, 9 Grinding wheel,
10 grinding wheel base, 11 workpiece, 12 probe, 13 amplifier, 14 A / D converter, 15 grinding control calculation unit, 16 CNC control device (grinding device),
17 CNC input unit (grinding device), 18 grinding wheel drive device, 19 grinding wheel base feeding device,
20 displacement amount recording unit, 21 CNC input unit (cutting device), 22 CNC control device (cutting device), 23 idle grinding start position calculation unit

Claims (6)

A cutting device for cutting a workpiece based on a preset value for cutting,
A grinding device for grinding the workpiece after cutting by the cutting device, based on a preset setting value for grinding,
After the tool of the grinding device quickly began advance, before the tool is in contact with the work, measuring unit for measuring the wobbling caused by the tilt as to the reference axis of the outer diameter and the work of the upper Symbol workpiece,
A storage unit that stores the outer diameter and the value of the deflection measured by the measurement unit for each workpiece,
And a grinding allowance target value that calculates a target value of the grinding allowance to be left in the cutting process based on the average value and variation index of the deflection of the predetermined number of workpieces stored in the storage unit and transmits the calculated value to the cutting apparatus. With an arithmetic unit,
The cutting device changes the setting value for cutting based on the target value of the grinding allowance transmitted from the grinding allowance target value calculation unit, and performs the cutting based on the changed setting value for cutting. A manufacturing system characterized by that. A cutting device for cutting a workpiece based on a preset value for cutting,
A grinding device for grinding the workpiece after cutting by the cutting device, based on a preset setting value for grinding,
Before performing the grinding process, in the grinding apparatus, a measurement unit that measures the outer diameter of the workpiece and the deflection due to the inclination of the workpiece with respect to the reference axis,
A storage unit that stores the outer diameter and the value of the deflection measured by the measurement unit for each workpiece,
A grinding allowance target value calculation that calculates a grinding allowance target value to be left in the cutting process based on the average value and variation index of the predetermined number of workpieces stored in the storage unit and transmits the calculated value to the cutting apparatus. Part,
And in the grinding process by the grinding apparatus, a blank grinding start position calculating unit that calculates a blank grinding start position before the workpiece and the tool are in contact with each other,
The blank grinding start position calculation unit calculates the blank grinding start position using an index regarding the outer diameter of the predetermined number of workpieces stored in the storage unit and an average value and variation of the workpiece ,
The cutting device changes the setting value for cutting based on the target value of the grinding allowance transmitted from the grinding allowance target value calculation unit, and performs the cutting based on the changed setting value for cutting. Concrete system made you, characterized in that.   The manufacturing system according to claim 1, wherein the index relating to the variation is a standard deviation. A display unit for displaying a distribution of the outer diameter and runout of a predetermined number of the workpieces stored in the storage unit;
The manufacturing system according to claim 1, wherein the index relating to the variation is a value selected from the distribution. A display unit for displaying the outer diameter and runout of the workpiece stored in the storage unit in time series;
The said predetermined number of data are acquired from the said memory | storage part by selecting the time-sequential range displayed on the said display part, The Claim 1 characterized by the above-mentioned. Manufacturing system. In a manufacturing method for manufacturing a workpiece using a cutting device and a grinding device,
A cutting process for cutting the workpiece by the cutting device based on a preset setting value for cutting,
After the tool of the grinding apparatus quickly began advance, before the tool is in contact with the workpiece after the cutting by the cutting step, measure the wobbling caused by the tilt as to the reference axis of the outer diameter and the work of the upper Symbol workpiece Measuring process,
A storage step of storing the outer diameter of the workpiece and the value of the deflection measured by the measurement step in a storage unit for each workpiece;
A grinding step of grinding the workpiece after cutting by the cutting step by the grinding device based on a preset setting value for grinding,
And a grinding allowance target value that calculates a grinding allowance target value to be left in the cutting process based on an average value and an index of variation of the predetermined number of workpieces stored in the storage unit, and transmits the calculated value to the cutting apparatus. Including the calculation process,
The cutting device changes the setting value for cutting based on the grinding allowance target value transmitted from the grinding allowance target value calculating step, and the cutting step is based on the changed setting value for cutting, The manufacturing method characterized by performing the said cutting process.