FR2467056A1 - HONAGE RECTIFICATION MACHINE-TOOL - Google Patents

Abstract

Honing grinding machine tool comprising devices for entering and evaluating the dimensions of the honed part. A honing machine 1 is associated with a device 9 for measuring the dimensions of the part, followed by an electronic converter 31 connected to a measuring control device 30 collecting the measured values transformed into electrical signals. The measuring control apparatus 30 is followed by a statistical evaluation device 56. (CF DRAWING IN BOPI)

Description

The invention relates to a rectification machine tool

  by honing with devices for seizing and

  exploit the odds of the honored coin.

  It is known from German Patent 25 50 770 to measure the bore of the workpiece during or after machining

  and derive correction values for the modification of

  race of the honing head.

  Furthermore, the German patent application 19 50 112 describes a device for the last phase of machining parts on honing machines, controlled according to

  of the coast, with which one is perfect thanks to a job

  rification, adjusting the approach of the honing head

  according to a measurement of the diameter.

  All conditions are thus ensured so that,

  in a series production, the machined parts are

  within preset tolerances, however tight they may be. The control of the manufacture is generally carried out by statistical quality control. Random samples are taken during the manufacturing process; we mean by lots of pieces, a number

  limited machined parts immediately one after the other.

  The collected parts are measured with great precision out of the honing machine, and with the measured values, the usual statistical characteristic quantities are calculated, for example the average value (x), the standard deviation

(S) and the variance (V).

  However, these controls are time-consuming and therefore very expensive, especially since the precise measurement must be performed outside the honing machine at another measurement location. Therefore, for economic reasons, the checks can not be carried out

often it would be desirable.

  The object of the invention is to develop a device

  of the type referred to above, so that it

  automatically generate the data necessary for statistical quality control, without the need to transport the parts to another location and to measure them.

2 2467056

  This object is achieved according to the invention by virtue of the fact that at the honing machine is associated a device for

  measurement of the room, followed by an electronic converter

  connected to a measurement control device re-

  picking the measured values transformed into electrical signals, and that this measuring control apparatus is

  followed by a statistical evaluation device.

  According to the invention, the measuring device

  therefore only inside the honing machine, which preferably works with a pneumatic measuring buffer,

  known in itself, an electronic converter and a device

  evaluation. The device measures the honored bore of the part in several axially distant planes, one of which

  the other being an electronic calculator, recorded

  trant and directly processing the measured values, which is connected by an interface unit to a printer that edits measured values and statistical magnitudes

  characteristics. The result is thus immediately

  printed honors, which can be directly processed

  your. This has many advantages, for example a reduction in setting times and fewer rejects, since it is possible to immediately optimize the honing results by appropriately modifying the results.

machining parameters.

  In an advantageous embodiment, the arrangement

  measuring device, that is to say a measuring device that controls the dimensions of the already machined parts and is connected to a control device for automatic adjustment

  of the race, which includes a converter for

  the measured values of the geometry of the part into correction signals and which is electrically connected to the evaluation device so that the reversing points of the working stroke can be moved

  according to the measured form defects of a machined part.

  and these shape defects are introduced at the same time into an electronic calculator which calculates the characteristic statistical quantities necessary for the quality control and supplies them printed with the measured values, via a

  printer connected to an interface unit.

  Deformities are understood to mean the divergence between the machined part and a predetermined theoretical shape. In general, the theoretical form is a cylinder (according to DIN 7184). However, it is possible without difficulty to predetermine by departing from the theoretical form, for example a slight taper, a partial taper, a

barrel shape or the like.

  The checking of the dimensions is advantageously done by a comparison with a control ring which is at the

  theoretical rating. Deviations from this theoretical rating

  Ideally, which occur for example by the wear of the control ring, can be compensated by electrical means by introducing a correction. In addition,

  thanks to an automatic reset, one excludes

  the measuring installation, for example under the influence of

temperature.

  The measuring apparatus, which preferably works pneumatically and is equipped with a measuring zone, is introduced axially into the bore of the workpiece.

  measure and is moved from one measurement plane to another. always

  However, it is also possible that the measuring apparatus itself has several measurement zones distant axially. The measuring device is preferably moved by means of a hydraulic cylinder in which the stroke control works with an electric potentiometer of real value and several potentiometers

  theoretical value as well as with an electronic device

  analogical evaluation. The electronic device

  evaluation of the tension of the cursor arriving from the

  real-time tentiometer, which is an analog measurement for the instantaneous position of the measuring instrument with the voltages provided by the theoretical value potentiometers which represent the respective measurement planes, and in case of equality of values, transmits a signal which is used for the hydraulic control of the race

of the measuring device. -

  A particular advantage here is the possibility of

2467056.

  remote adjustment of the measurement planes, the possibility of modifications during operation and the possibility to call up the measured measurement plans thanks to a digital display. According to another characteristic of the invention, it is also possible to record at the same time on a

  second data carrier, for example with a perforation

  punched tapes, measured values, and calculation results from the computer. We use

  this possibility when the measured values are processed

  mechanically outside the honing machine.

  A particularly advantageous solution for machining parts fitted together, such as cylinder and injection pump piston, is to process the parts in batches and to record on a perforated strip the measured dimensions.

  parts, the measurement temperature and the batch number.

  This perforated band is introduced into the machine cor-

  corresponding to the machining of the opposite parts, which due to this information, factory with great precision

  of adjustment and affects the opposite parts.

  The invention will be well understood on reading the

  detailed description, given below as an example

  only, an embodiment shown in the single figure which shows schematically and in part

  in the form of block diagrams a honing machine con-

form to the invention.

  In a honing machine 1 is mounted a honing spindle 2 which is moved up and down by a hydraulic movement mechanism, namely a jack 3. The honing spindle 2 is further rotated about its axis. longitudinal axis in a known manner

  by a rotating drive (not shown).

  sented). Honing pin 2 carries a honing head 4, whose stick-stones can be approached radially

  to the outside by an approach mechanism (not shown

  S), and which, in the example shown, mills the bore of a workpiece 6. A potentiometer 7 is connected to the honing spindle 2 and serves as a true value indicator of the stroke. In

2467056 1

  the example shown, the drive link between the honing spindle 2 and the slider of the potentiometer 7 is constituted

by a chain drive 8.

  The raising and lowering movement of the mechanism 3 is controlled by a magnetic valve 18, the relay coil 19 of which is controlled by a control device.

  20. This apparatus 20 is an electronic device

  analogically, the basic structure and operation of which are described in the

German 24 35 498 and 25 50 770.

  Essentially, the race control device

  consists of two potentiometers of

  21 and 22, a correction member 23 and a device

  comparison and evaluation. 24. Of the two potentials

  set point meters 21 and 22, it is possible to set

  digital input, via a button for

  ge, the desired inversion points of the movement of the

  honing pin, thanks to which an analog voltage cor-

  respondent to this setting is first brought to the cur-

associated potentiometer.

  These voltages are brought to the correction element

  23 which has several entries 25, to which are

  values that influence the setpoints

  reversal points, upper and lower, for example

  many values for the initial contact delay, the

  temperature of the oil in the hy-

  hydraulics, the variation of the speed of climb and des-

  the variation of drive power, etc.

  Another input 26 of the body organ is provided.

  23 for the introduction of values for the order

  the geometry of the workpieces.

  The comparison and evaluation device 24 compares the voltage coming from the actual value indicator 7, taken from the potentiometer slider, which constitutes

  an analog measurement of the momentary position of the bro-

  Honing step 2, with set point voltage

  corrected by the correctional body 23 which

  is an analog measure of the reversal point of com-

  higher, or lower, desired. When the

2467056 ":

  theirs, the system of comparison and evaluation

  24 emits a control signal which is explained to reverse the control of the run of the break-in spindle,

  as is explained in more detail in the German patent.

mand 24 35 498.

  In addition, a measuring device 9 is provided,

  carrying a measuring pin that is moved upwards

  and downwards by a hydraulic stroke mechanism 11.

  The measuring pin 10 carries a measuring tool 12, which

  is the bore 13 of a coin 14 already honored.

  The measurement control is carried out advantageously

  by a comparative measurement by means of a ring of con-

  control 64 placed, in the example shown, above

  14. The arrangement is in this case preferably designed

  so that the control measurement plane G passes through the measuring tool 12 in the upper terminal position of the travel mechanism 11. A potentiometer 15 is connected to the measuring pin 10 and serves as an indicator

  of real value for the stroke of the tool 12. In the

  As shown, the connection is constituted by a cremaill-

  lere 16 fixed on the measuring pin, which meshes

  with a pinion 17 secured to the shaft of the potentiometer.

  The hydraulic stroke mechanism 11 is controlled by a magnetic valve 27 for the up and down movement; the relay coils 28 and 29 of the magnetic valve are controlled by a control device of

measure 30.

  The measuring tool 12 preferably operates

  in a known manner. The measured values arriving from the measuring tool are fed to a measurement converter 31 which transmits these measured values in the form of

  electrical signals to the measuring control device 30.

  In the example shown, successive measurements were

  the dimension KG of the control ring in the measuring plane G, the dimension WA of the part at the upper end of the bore in the plane A, the dimension WB of the part in the middle of the bore in the plane B and the WC dimension of the part at the lower end of the bore in the plane C. The measurement control apparatus 30 is an analogical electronic apparatus whose basic structure and operation will be described below. As soon as an honored piece is in the device

  9, a signal arriving from the control of the machine

  not (not shown) reaches the input of control signals 32 of the race controller 33. This triggers the measurement operation. It begins each time with the measurement of the KC dimension of the control ring in the plane G. Then, the stroke control member 33 excites the relay coil 29 of the magnetic valve 27 which controls

  the running mechanism and triggers the descent of the bro-

  measuring head 10 with the measuring tool 12.

  Potentiometer 15 connected as an indicator of

  actual value at the measuring spindle 10 provides, through the

  through its cursor, a tension on the

  33, which represents an analogue measure

  than the instantaneous position of the measuring tool. An input device 34 includes a potentiometer 35 for the electrical adjustment of the actual value indicator 15 with respect to the measurement plane G of the control ring;

  furthermore, the input device 34 has potentials

  meters 36, 37 and 38 as setting value indicators for adjusting the position of the measuring planes

A, B and C of the workpiece.

  The stroke control member 33 compares the voltage arriving from the potentiometer slider of the actual value indicator 15 successively with the voltages provided by the adjustment value indicators 36, 37 and 38, and, in case of coincidence, it transmits a control signal which causes a brief stop of the race control mechanism 11. During these brief stops, the measurements are executed

  in plans A, B and C. At the same time, a second

  The control signal causes the measured values supplied by the measurement converter 31 to be transferred to a memory 39. When the measurement is complete at the end

  lower part (measuring plane C), the

  command 33 sends to the relay coil 28 of the relay

8 2467056

  magnetic fart 27 a command signal that causes the

  return of the measuring tool 12 to the upper starting position

  higher (measurement plane G). The measuring tool is ready

for the next measurement.

  The memory 39 advantageously comprises an automatic reset which reduces the measured value KG in the

  measurement plan G to the value zero and agoute cha-

  that times the difference found, with the correct signs, between this zero value and the measured values of the piece WA, WB and WC. With this arrangement, it compensates for any drift of the measuring installation; therefore, the deviations of the measured values that can come from

  including, for example, temperature or other influences

  these exteriors on the measuring installation.

  The signals from the memory 39 are fed to an analog computer 40. To the analog calculator

  is also connected, to enter values of cor-

  rection, an input device 41 which, in the example shown

  sent, includes a potentiometer 42 for the correction of the KC dimension of the control ring and the potentiometers 43

  and 44 for correcting WA and WC dimensions of the part.

  A correction input to the potentiometer 42 is by

  necessary example, or appropriate, when the ring of con-

  Tr8le 64 no longer, due to wear, for example, the exact nominal dimension of the workpiece. the input causes a displacement of the measurement plane G which constitutes the comparison plane for the planes A, B and C of the part. The value

  correction is added to the measurement signals.

  Measuring signals - possibly corrected -

  represent the deviations of the part from a predetermined ideal part having an exact dimension and a shape

precise, for example cylindrical.

  In order to be able to predetermine a form of instruction

  deviating from the cylindrical form, the potentials

  correction meters 43, or 44 the desired deviations in the measuring plane A (upper end of the workpiece), or in the measurement plane C (lower end of the workpiece), with respect to the measuring plane B (middle of the workpiece). piece). The value

  possibly introduced for measurement plan A is

2467056;

  assigned to the measurement signal for the WA dimension of the part; in the same way, the value possibly introduced for the measuring plane C is assigned to the measurement signal for the WC dimension

  of the room; these predetermined values may be added

  measured values, but another type of combination

is also possible.

  From the measured values thus obtained, which can therefore be corrected, the electronic computer 40

  calculates by means of a subtractor the differences in

  their measured measurement planes B and A, B and C, as well as

  A and C, so WB-WA, WB-WC and WA-WC. These difference values

  the difference in the form of

  predetermined pattern. The calculated values are transmitted,

  with the measured values, to an evaluation device 45.

  In addition, these values are provided through a display selection switch 46 to a display 47 in which they can be displayed digitally or analogically. At the display selection switch 46 is further connected a signal link pipe 48 from the

  33. It is thus possible to display on the

  tif display 46 also the pisition of measurement plans

  previously provided to the input device 34.

  To the evaluation device 45 is connected, for the introduction of limit values, an input device 49, which in the example shown, comprises a potentiometer

  preselection of limit values for the correction of

  race in case of defects in shape, a potentiometer

  52 for the pre-selection of limit values for the identification

  waste in the event of defects in shape, and a potential

  meter 53 for the preselection of limit values for

  identification of the rejects in the event of deviations of odds.

  The amount of the signal difference values provided by the analog computer 40 WB-WA and WB-WC is compared in the evaluation device 45 with the value

  limit set to potentiometer 50. If the limit value

  determined for the difference in form is exceeded, the

  Evaluation Unit 45 sends a signal to input 26 of the

  same race control 20 which then causes a corresponding correction in vertical displacement. If by

  For example, the difference in measured values WB-WA is posi-

  that is, if the dimension measured in plan B is

  greater than the measured value of Plan A, a

  upset of the control reversal point "(al-

  along the race); if the difference in the measured values

  is negative, the correction takes place towards the "low"

  duction of the race). It's the same for the difference

  of measured values WB-WC with regard to the point of in-

lower order version.

  It should be noted that, when machining blind bores and the like, o, because the clearance by groove is mostly missing at the bottom of the bore or is insufficient, a stroke correction is impossible, other quantities that influence the shape of the bore can be corrected. Thus, for example, in a honing machine with stroke retardation control, as described in German Patent No. 21 04 45.9, the delay time is appropriately corrected. If, for example, the difference WB-WC is positive, the delay time is lengthened; if

  this difference is negative the delay time is rac-

Courci. -

  In the evaluation device 45, the amount of the measured values of the differences WB-WA, WB-WC and WA-WC is compared with the limit value set at the potentiometer 52. If, due to too large formal defects, the predetermined limit value for identification of the waste is exceeded, the evaluation device 45 emits at its output 54 a signal

  which is brought to the machine control (not shown).

  The part is thus identified as discarded and sorted

  automatically by means known per se.

  In addition, a comparison is made in the evaluation

  45 the measured value WB, provided by the analog calculator 40, which is decisive for the final rating of

  the bore of the workpiece, with the limit value set at

  Tentiometer 51 or potentiometer 53. If the measured value WB exceeds the limit value for the readjustment of the tool

  predetermined at the potentiometer 51, the evaluation device

  45 sends by its output 55 a signal to the approach control (not shown) for the honing head, which correspondingly corrects its approach. If, because of a large difference in dimension, the measured value WB exceeds

  the limit value set to potentiometer 53 for the identification

  In addition, the evaluation device 45 sends a signal to the machine control (not shown) via its output 54. The piece is then marked as discarded

and sorted.

  According to an advantageous characteristic of the honing device of the invention, the measured and calculated values provided by the analog calculator 40 to the device

  45, in the example shown the values me-

  WA-WC ratings are sent to an evaluation device.

statistical evaluation 56.

  The statistical evaluation device 56 is a digitally operated electronic device, the

  basic structure and function will be described below.

  after. Measured values provided by the device

  in the form of analogue signals are

* born to a converter of measured values 57 which trans-

  these measured values into digital signals and the

sends to a microcomputer 58.

  The calculator 58 is preprogrammed for calculation

  characteristic statistical magnitudes in view of the con-

  very good quality. It comprises a keypad 59 for the manual entry of quantities, which influence the calculation program and their progress, for example a value for the batch size (number of pieces) which is

posited as the basis of the calculation.

  The measured values provided by the measured value converter are stored in a computer connector memory 58 and printed with a serial number of the parts by means of a printer 61.

  Another advantageous characteristic of the invention is that

  Furthermore, it is possible to print various other data, namely a part identification number, the date and time of the measurement and the measurement temperature which has been obtained in a known manner during the measurement. The printer

  is connected to the computer 58 by an interface unit 60.

  When the predetermined quantity of the batches is reached, the characteristic statistical quantities are calculated and printed, in the example represented the average value (x), the standard deviation (S) and the variance (V). Depending on the input to be introduced by a switch, one calculates with "n" or "n-1", "n" being the number of pieces memorized. The

  set quantity of the lot may at any time be made visible

  ble on the computer's display panel 62 and be

  modified by means of the keys on the keypad 59.

  According to another characteristic of the invention, the measured values and the results of the calculations may also be placed on another data medium, for example on a perforated strip by means of a perforator 63 which is connected

  to the computer 58 parallel to the printer 61 by the in-

  intermediate of the interface unit 60.

  The storage of the measured values and the re-

  The results of calculations on perforated tape or on any other data medium have the advantage of allowing further mechanical processing of these data out of the

honing machine.

  A special advantage of the honing machine

  according to the invention consists in that for each piece

  machined on the honing machine, for example a

  injection pump cylinder, one can polish on one

  x machine an opposite piece rigorously adapted,

  for example a piston on an external cylindrical grinding machine

  pool. Precisely adjusted and adjusted parts can also be assigned to each other.

  the other by means of the data carrier.

  For the manufacture of parts thus adapted to each other, the parts are collected for example in batches, in groups and machined. On the data carrier, (perforated tape) the batch number or any other

  characteristic for the group, the date and time, the time

  measurement values as well as the characteristic values of the parts, namely the measured dimensions of the parts and the results of the calculations, the serial number of the parts, the identification number of the parts and possibly 1 3

  other data. The data carrier, for example a bank

  perforation is set in the corresponding measuring command.

  te of the machine for possible machining in groups

  opposite parts, so that depending on these information,

  the machine can manufacture opposed parts

precisely. Since group or batch numbers

  and the series of parts within the group are recorded

  As data, one can determine and assign to each other the parts going together for the assembly, this

  which ensures particularly precise adjustment accuracy.

0 0 0 0

0 O 00

14 2467056-

Claims (21)

REVENDI CATIONS   1. - Compensation honing machine tool   carrying devices for grasping and exploiting the dimensions of the honed coin, characterized in that the honing machine (1) is associated with a device (9) for measuring the dimensions of the coin, followed by an electronic converter   (31) connected to a measurement control apparatus (30)   picking measured values transformed into electrical signals   and that this measuring control device (30) is   followed by a statistical evaluation device (56).   2. - honing machine according to claim 1, characterized in that the measuring device (9) with its   measuring tool (12), preferably a pneumatic buffer   known in itself, is placed in the honing machine and is intended to measure the bore of the workpiece (13) in   several planes (A, B, C) ex-   be. 3. - honing machine according to claim 1 or claim 2, characterized in that the device   measuring device (9) comprises a measuring pin (10) with the   measuring tool (12) driven by a hydraulic drive (11), which is provided to control the dimension of the hoists   (14), and that the measuring device (9) is provided with a   positive control for the automatic adjustment of the from the measuring spindle (10).   4. - Honing machine according to any one of   Claims 1 to 3, characterized in that the measurement of   control is a comparative measurement by means of a control ring (64) placed outside the workpiece   (14), so that in the upper terminal position   movement mechanism (11), the measuring tool (12) is in the control measuring plane (G) of the control ring (64).   5. - Honing machine according to any one of   Claims 1 to 4, characterized in that at the spindle of   measurement (10) is connected an actual value indicator (15) for the vertical stroke, and that a connection is provided for example with a rack (16) placed on the spindle of   measurement (10) and a pinion (17) meshing with this cremaill-   lere and placed on the real value indicator tree (potentiometer (15).   6. - Honing machine according to any one of   Claims 1 to 5, characterized in that the device   for controlling the travel of the measuring spindle (10) comprises   a magnetic valve (27) controlling its movement of   tee and descent, including relay coils (18, 19)   connected to the measuring control device (30), in particular   to the stroke controller (33).   7. - Honing machine according to any one of   Claims 1 to 6, characterized in that the apparatus for   an electronic measurement control (30) operating analogically to a stroke controller (33) which is connected, on the one hand, to the control of the honing machine (1, 32) to the actual value indicator ( potentiometer) (15) and to the relay coils (28, 29) of the measuring device (9), and on the other hand with an input (34) for setting the actual value indicator (15) on the plane measurement (G) and setpoint indicators (36,   37, 38) on the measurement plans (A to C) as well as on a   (39) followed by an analog calculator (40), the   memory, for its part, is electrically connected to the con-   energizer (31) mounted after the measuring device (9). 8. - honing machine according to claim 7,   characterized in that an entry (41) of correction values   preferably having potentiometers (42, 43, 44) for the measured values (WA, WB, WC) is connected to the analog calculator (40).   9. - Honing machine according to any one of   Claims 1 to 8, characterized in that the calculation   analog transmitter (40) is provided with a selector switch   display (46), a signal link (48) preferably being placed between the selection switch   display (46) and the stroke controller (33).   10. - Honing machine according to any one of   Claims 1 to 9, characterized in that   between the evaluation device (45) and the stroke control apparatus (20) of the honing machine (1) a 2467056 "   an input control (26) for the geometry of the tool.   11. - Honing machine according to any one of   Claims 1 to 10 characterized in that the memory (39)   includes an automatic reset, so that the value measured in the measuring plane of the calibration ring (G) is taken for zero and that the difference found with respect to the zero can be added to the values of the ratings   measured on the piece with the correct signs.   12. - honing machine according to any one of   Claims 1 to 11, characterized in that   the evaluation device (45) an entry of limited values   (49) for the purpose of preselecting limit values for   the racing device due to defects in shape (po-   50), for the purpose of preselecting limit values   for correcting the approach of the tool because   of odds (potentiometer 51), for the purpose of   selection of limit values for waste identification   due to defects in shape (potentiometer 52) and a   limit value selector (53) for the preselection of   limit values for waste identification purposes its defects - odds.   13. - Honing machine according to any one of   claims 1 to 12, characterized in that the   evaluation circuit (45) comprises signal paths (26) towards the correction element (23) of the stroke control apparatus (20), signal paths (54) for the control device Honing Machine (1)   and signal paths (55) for the communication device the honing tool (4).   14. - Honing machine according to any one of   Claims 1 to 13, characterized in that a   statistical evaluation apparatus (56) following the   positive evaluation (45) to transmit to the device   (45) measured values and cal-   abutments provided by the analog calculator (40).   15. - Honing machine according to any one of   Claims 1 to 14, characterized in that the apparatus   statistical evaluation system (56) comprises a converter (57) in which the measured value signals arriving 2467056.   of the evaluation device (45) can be transformed   in digital signals and can be sent to a micro-   computer (58) mounted thereafter, preferably provided with a keyboard with keys (59).   16. - Honing machine according to any one of   Claims 1 to 15, characterized in that the values   measured values provided by the converter (57) can be   stored in a data memory of the micro-cal-   (58) and that they can be printed together with a serial number of the parts by a printer (61) ascent.   17. - honing machine according to claim 16, characterized in that identification data such as room identification numbers, date, time of the   measurement, temperature of the measurement etc. can be printed   at the same time by the printer (61).   18. - honing machine according to claim 16 or claim 17, characterized in that the printer (61) is connected to the computer (58) via an interface unit (60).   19. - Honing machine according to any one of   claims 1 to 18, characterized in that the ratings of   can be called on the display (62) of the cal-   the culator and be modified by means of the keyboard (59) of the computer.   20. - Honing machine according to any one of   claims 1 to 19, characterized in that the values   measured and the results of the calculations can be put, besides the printer (61) also on at least one other   data carrier, for example by means of a perforator this perforated tape (63).   21. - Method for machining a workpiece, for example   a cylinder, on a machine of honing according to some   of the preceding claims, characterized in that   whereas, for the automatic assignment of an associated part, for example a piston, to be machined with a high accuracy of fit on another machine tool, the parts to be honed are machined in batches and the measured dimensions of the parts, the calculation results as well as other data such as 2467056.   that part numbers, part numbers, date, time, temperature of measurement, lot number are   recorded on a data carrier, for example a bank   perforation, and that these values, for the purpose of controlling the other machine tool on which the opposite parts are also batch machined, are introduced into this machine for the purpose of highly accurate machining of these opposite parts.