JP2005335036A - Cylindrical grinding device and method for measuring outer diameter of workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical grinding device measuring the outer diameter of a multiple-stage cylindrical workpiece in a highly precise manner, using the size measurement apparatus equipped with a touch probe. <P>SOLUTION: On a spindle stock 4 installed on left and right movable tables 3 which are established on a frame 2 of the cylindrical grinding device 1, and on holding means composed of a tail stock 5, a longitudinal cylindrical workpiece w is placed so that its axis is maintained in a horizontal state. This workpiece w is ground by means of a grinding wheel, whose axis is linked with a wheel axis of the wheel head 8, fixed to the wheel spindle head 7, in such a way that the wheel head 8 is moved forward and backward along the line crossing at a normal angle with the core of the work piece w. In this arrangement, a probe 12a of the work size measuring instrument 12, which is attached to the forward side (countering the workpiece) of the wheel head 8 in the manner movable upward/downward, contacts the work piece w. The outer diameter R<SB>i</SB>at the work measurement location is then calculated to be R<SB>i</SB>=2x¾X<SB>0</SB>-X<SB>i</SB>¾, based on work outer face location signal X<SB>i</SB>issued as a result of the contact between the probe 12a and work piece, and the standard signal X<SB>0</SB>issued as a result of contact between the size measurement standard face of master block M<SB>1</SB>, formed at the backward side of the tail stock countering the wheel head, on one hand, and the probe 12a, on the other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cylindrical grinding apparatus and an outer diameter measuring method capable of measuring an outer diameter of a long cylindrical workpiece, particularly a multistage cylindrical workpiece during grinding. According to the method of the present invention, the outer diameter can be measured using a simple workpiece dimension measuring instrument over the longitudinal direction of the cylindrical workpiece. Further, it is possible to accurately measure the length from the chuck surface of the multistage cylindrical workpiece to the end surface to be measured.

A cylindrical workpiece is subjected to traverse grinding, plunge grinding, and shift plunge grinding using a cylindrical grinding apparatus. In order to grind the outer diameter of a cylindrical workpiece with a grinding wheel of an NC cylindrical grinding device with high accuracy, the outer diameter of the cylindrical workpiece whose outer surface has been ground is measured using a workpiece size measuring instrument. When the measurement is completed and a dimension completion signal is received from the output unit of the control device, the cutting of the grinding wheel is terminated. As such a dimension measuring instrument, there is a direct sizing device in which a pair of measuring fingers provided with measuring elements contacting both sides of the workpiece diameter are brought into contact with the workpiece surface and the displacement is read by a displacement sensor. (See, for example, Patent Document 1, Patent Document 2, and Patent Document 3.)
JP-A-6-79622 JP 2002-283230 A JP 2002-120147 A

When the cylindrical workpiece has a multi-stage outer diameter as shown in FIG. 4, a high-precision stroke positioning accuracy between the workpiece and the measuring finger contact is required. Since the measurement range and the measurement outer diameter are narrow due to the limit of the stroke amount and the limit of the escape amount of the measurement finger, the direct sizing device including the pair of measurement fingers is used, for example, A method is being considered.
1) A plurality of direct sizing devices having different distances between measuring fingers due to differences in the outer diameter of the multi-step part of the work are installed for each step part.
2) As disclosed in Patent Document 3, the measuring finger (pressing element) is attached in a state displaceable in the radial direction of the workpiece, and the pressing element is attached to the workpiece. There is a pressing means that can move on the guide device so that it can move forward and backward in the radial direction of the workpiece, and a direct sizing device that measures the outer diameter of the workpiece on the substantially same outer peripheral surface in the axial direction as that of the workpiece. .
3) A sizing device is provided directly on the guide device that moves in a direction parallel to the axis of the workpiece, above the workpiece close to the grinding position of the workpiece.

  In the method 1), it is necessary to directly provide a plurality of sizing devices, and the work area is reduced. In the method 2), the measurement moving stroke of the presser needs to have a stroke larger than the grinding amount of the workpiece. Further, in order to avoid contact of the presser with the workpiece when the workpiece is attached to or detached from the workpiece holding means, a guide device having a stroke that moves back and forth a distance greater than the radius of the workpiece is required. The installation area of the device increases. In the method of 3), it is necessary to increase the distance from the position where the pressing element of the sizing device contacts the work surface to the guide device where the sizing device is provided, The outer diameter dimensional accuracy measured under the influence of vibration is reduced.

  The present inventor paid attention to the fact that an end face position dimension measuring device using a touch probe is used to detect the left and right positions of the step during multi-stage cylindrical grinding, and this touch probe was used. An object of the present invention is to provide a cylindrical grinding device capable of measuring the outer diameter of a workpiece with high accuracy using a dimension measuring device.

The invention of claim 1 is a holding means comprising a left and right moving table provided on a frame, a headstock and a tailstock installed on the left and right moving table, and comprising a long cylindrical wall. -Holding means for holding the shaft so that its axis is in the horizontal direction, a grindstone head attached to a grindstone table movably provided in the front-rear direction perpendicular to the axis of the long cylindrical workpiece; A grinding wheel provided on the grinding wheel head so that its axis is parallel to the axis of the workpiece, a rotational drive mechanism of the grinding wheel, and ascending / descending vertically on the front side facing the workpiece of the grinding wheel head A workpiece dimension measuring instrument having a dimension measuring probe which outputs a signal when a probe attached to a stylus tip that can be attached comes into contact with the workpiece, on the rear side of the tailstock facing the grinding wheel head A master block serving as a dimension measurement reference surface and the dimension measurement probe are transmitted. Recording unit receives a signal control unit, word - from the distance X ₀ to dimensional measurement reference surface of the block - the distance X _i and word to the axial center surface the stylus contacts the click - click of the axial center master Provided is a cylindrical grinding apparatus including a calculation unit and an output unit for calculating an outer diameter R _i of a measurement portion of a long cylindrical workpiece as R _i = 2x | X ₀ -X _i |.

According to a second aspect of the present invention, a workpiece size is obtained by using the cylindrical grinding device, and by moving the grinding wheel head in the front-rear direction, moving the holding means in the left-right direction, and moving the workpiece dimension measuring device up and down. Bed the word - - dimensional measurement professional measuring instruments into contact with the click surface, the elongate cylindrical follower - there is provided a method of measuring the outer diameter R _i of click measurement points.

According to a third aspect of the present invention, there is provided a cylindrical grinding apparatus in which another master block serving as an end face position dimension measurement reference surface is installed on a frame in the vicinity of the rear side of the headstock of the cylindrical grinding apparatus. is there.

Due to the relative movements of the left / right (Z-axis direction) moving table, the grindstone table movably provided in the front-rear direction (X-axis direction), and the vertical direction (Y-axis direction) lifting mechanism of the touch probe, Wa - the stylus tip click dimension measuring instrument pro - Bed is word - in addition to possible contact with the click rear, master provided near the tailstock - contact with the front face of the block M _1, and provided in the headstock vicinity master - so mounted for contact to the side surface of the block M _2, word - it is possible to calculate the position where blanking is in contact with the control device - and the outside diameter of the click, professional from the headstock chuck end face . The coordinate of the contact point of the probe is (X _i , Z _i ), where the axis of the work is the Z axis, the longitudinal axis orthogonal to the Z axis is the X axis, and the front X axis coordinates of the master block M ₁ Is X and the side coordinate of the master block M ₂ is Z ₀ , the outer diameter R _i of the workpiece measurement point where the probe of the long cylindrical workpiece is in contact is | X ₀ -X It is calculated as 2 times _i |. The distance from the chuck end surface of the headstock to the workpiece measurement point where the probe of the long cylindrical workpiece is in contact is calculated as | Z ₀ −Z _i |.

Hereinafter, the present invention will be described in more detail with reference to the drawings.
1 is a plan view of the NC cylindrical grinding apparatus, FIG. 2 is a side view of the NC cylindrical grinding apparatus viewed from the II line in FIG. 1, and FIG. 3 is a sectional view of the NC cylindrical grinding apparatus from the II-II line in FIG. FIG. 4 is a side view, and FIG. 4 is a flow diagram in a multistage traverse grinding process of a multistage cylindrical work.

  In the NC cylindrical grinding apparatus 1 shown in FIGS. 1, 2 and 3, 2 is a frame, 3 is a left-right moving table provided on the frame, 4 is a headstock, and 5 is a tailstock. Thus, a work holding means is formed by the spindle stock and the tailstock. The holding means including the headstock and the tailstock is installed on the left and right moving table 3, and the axis of the multistage cylindrical work (long cylindrical work) w is in the horizontal direction. Are held by the chucks 4a and 5a. This multi-stage cylindrical work w is rotated about its axis by a drive motor 4b provided on the headstock 4. 6 is a dresser.

Reference numeral 7 denotes a grindstone table that moves forward and backward in the front-rear direction (X-axis direction) on the frame. Reference numeral 8 denotes a grinding wheel head which is mounted on the grinding wheel base 7. Reference numeral 9 denotes a grinding wheel which is supported on the grinding wheel shaft 10 of the grinding wheel head 8 and is rotationally driven by a driving motor (not shown). Reference numeral 11 denotes a work shaft, and reference numeral 12 denotes a work dimension measuring instrument provided with a touch probe 12a. A probe 12a is provided at the tip of the stylus 12b, and is positioned when contacting the work w. Give a signal. The touch probe 12a at the tip of the stylus of the workpiece size measuring instrument 12 can be moved up and down (Y-axis direction) by an elevating mechanism 13, and a slide member 13b provided with the touch probe is illustrated. It moves up and down in the guide portion 13a in response to the drive of the motor that is not. The touch probe lifting mechanism 13 is attached to the front side of the tailstock 5 facing the rear surface of the long cylindrical workpiece w.

Grinding head 8 opposite to the tailstock 5 rear a dimension measurement reference plane on the master - block M ₁ is a side near the rear of the headstock 4 frame - another master different from the dimension measurement reference plane on the arm - block M ₂ is installed. These master blocks M ₁ and M ₂ are used to prevent a dimensional error caused by a slight inclination in the longitudinal direction of the stylus 12b. That is, as shown in FIG. 4, when the multistage cylindrical work w is subjected to shift plunge grinding, the touch probe 12a contacts the work w and outputs a signal. Before or after contact of the touch probe 12a with the workpiece (usually before performing precision finish grinding), the touch probe 12a is brought into contact with the reference surface of the master block serving as a dimension measurement reference surface, and the dimensions are measured. measurements pro - Bed allowed is received by the recording unit of the control device outgoing signals, word - click the axial center touch pro - distance X _i and word to the surface where blanking is in contact - click the axial center master - block From the distance X ₀ to the dimension measurement reference plane, the outer diameter R _i of the measurement point of the long cylindrical workpiece is calculated as R _i = 2x | X ₀ -X _i | and output to the comparison unit. compared outer diameter value which has been stored in the storage unit and the value R _i, a signal for stopping the grinding if the two values match mode - outputs to the motor control unit.

Similarly, the coordinate center of the touch probe is set to (X _i , Z _i ) with the Z axis as the axis of the work, the X axis as the front and rear axes orthogonal to the Z axis, and the master block M ₁ . the front X-axis coordinate X, master - when the side coordinates of the block M ₂ and Z _0, the elongate cylindrical follower - from headstock chuck end surface of the click measurement locations - click touch pro - Wa which blanking is in contact The calculation unit calculates | Z ₀ −Z _i | as the distance to the workpiece measurement point where the touch probe of the multistage cylindrical workpiece is in contact. Here, the long axis 11 of the work coincides with the Z axis.

In order to grind the multistage cylindrical work w using the cylindrical grinding apparatus 1 of the present invention, the cylindrical work is held between the chucks of the headstock 4 and the tailstock 5 and the NC controller is operated from the operation panel. multi-stage cylindrical word processing in the recording unit of - each of click word - click end position Z _i and word - click OD r _i de of - enter the data in the recording unit, from the machining software displayed on the display device Select finish polishing software for multi-stage work. Then, the left and right tape - moving the table 3 to the left, and forward movement of the wheel head 7, word - click the dimension measuring instrument 12 is raised by the lifting device 13 pro - Bed 12a Master - rear surface of the blocks M ₁ contacting the master - outputs to the recording section of the control device the surface coordinates X ₀ after block M _1.

Then, the rearward movement of the wheel head 7, the right and left tape - and rightward movement of the table 3, Wa - click dimension measuring instrument 12 is lowered by the elevating device 13 pro - Bed 12a master - side of the block M ₂ contacting the master - output side coordinate Z ₀ of the block M ₂ in the recording unit of the control device.

Subsequently, after the workpiece dimension measuring instrument 12 is lifted by the lifting / lowering instrument 13, the left and right tables 3 are moved to the left, the grindstone table 7 is moved forward, and the workpiece is measured at each end of the workpiece. The position coordinates (X _i , Z _i ) of the contact point are output to the recording unit of the control device. Each was instructed in accordance machining programming software recorded in the storage unit of the controller word - click end position Z _i and word - de of click outside diameter r _i - a motor, pro - transmitted from Bed 12a, the arithmetic unit The calculated end position | Z ₀ -Z _i | and the value of the outer diameter 2x | X ₀ -X _i | at the stepped portion are compared, and the amount of finish grinding at each stepped portion is 2x | X ₀ −X _i | −r _i is calculated and output to the recording unit.

Based on the processing programming software, the workpiece w is finished and ground with a grinding wheel by the relative movement of the grinding wheel base 7 and the lateral movement of the left and right table 3, and the workpiece dimension measuring instrument. The outer diameter R _i of the workpiece at each end position calculated by the control unit according to a signal output by contact with the rear surface of the probe workpiece 12 or the reference surface of the master blocks M ₁ and M _2. Are compared with each end position and the target outer diameter r _i, and when the difference between the two is within the set allowable range, the shift to the next step is performed and the grinding is continued (FIG. 4). reference). If the value of the difference between the two does not reach the set allowable range, the correction grinding allowance by the grinding wheel is ground and the measurement is performed again.

  When finish grinding to each step is completed, a grinding completion signal is sent from the motor control unit to the servo motor of the cylindrical grinding machine, the grinding wheel is returned to the standby position, and the headstock is driven. The motor is stopped and the rotation of the work is terminated.

  A dimension measuring instrument 12 having a probe 12a at the tip of a stylus is available from Marposs or Renishaw.

  The cylindrical grinding apparatus 1 of the present invention can measure the outer diameter of a cylindrical workpiece using a dimension measuring instrument 12 having a probe 12a.

It is a top view of NC cylindrical grinding device of the present invention. It is the side view which looked at the NC cylindrical grinding device in FIG. 1 from the II line side. It is the side view which looked at the NC cylindrical grinding device in FIG. 1 from the II-II line side. It is a flow figure in the traverse grinding process of a multistage cylindrical work.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 NC cylindrical grinding machine w Multistage cylindrical work M ₁ Master block M ₂ Master block 2 Frame 3 Left-right movement table 4 Spindle head 5 Tailstock 6 Dresser 7 Grinding wheel head 8 Grinding wheel head 9 Grinding wheel DESCRIPTION OF SYMBOLS 10 Grinding wheel axis | shaft 11 Work shaft center 12 Work dimension measuring instrument 12a Touch probe 12b Stylus 13 Lifting mechanism

Claims (3)

Left and right moving table provided on the frame, holding means comprising a headstock and a tailstock installed on the left and right moving table, the long cylindrical work shaft having the axis Holding means for holding in a horizontal direction, a grindstone head attached to a grindstone head movably provided in a longitudinal direction perpendicular to the axis of the long cylindrical workpiece, and the axis of the grindstone head has an axis A grinding wheel provided so as to be parallel to the axis of the workpiece, a rotational drive mechanism of the grinding wheel, and a stylus tip attached to the front side of the grinding wheel head facing the workpiece so as to be vertically movable. A workpiece dimension measuring instrument having a dimension measuring probe which outputs a signal when the dimension measuring probe comes into contact with the workpiece, the dimension measurement provided on the rear side of the tailstock facing the grinding wheel head. The master block to be the reference plane and the signal transmitted by the dimension measurement probe Receiving the recording unit of the control device, Wa - axial center dimension measurement of click pro - Bed distance X _i and word to the surface in contact - click the axial center master - distance X ₀ to dimensional measurement reference surface of the block A cylindrical grinding apparatus comprising: an arithmetic unit and an output unit that calculate an outer diameter R _{i of a} long cylindrical workpiece as R _i = 2x | X ₀ -X _i |. Using the cylindrical grinding apparatus according to claim 1, the workpiece size measuring tool is moved by the relative movement of the grinding wheel platform in the front-rear direction, the holding means in the left-right direction, and the workpiece size measuring device moving up and down. dimension measuring pro - Bed the word - is brought into contact with the click surface, the elongate cylindrical follower - method of measuring the outer diameter R _i of click measurement points.   2. The cylindrical grinding apparatus according to claim 1, wherein another master block serving as an end face position dimension measurement reference surface is provided on a frame in the vicinity of the rear side of the headstock.

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