JP3865974B2 - Cylindrical grinding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a cylindrical grinding machine for measuring the position of a central axis of an eccentric cylinder integrated with a workpiece rotatably supported around a rotation axis, and particularly to a workpiece (eg, a crank). The present invention relates to a cylindrical grinding machine that measures the position of the central axis of an eccentric cylinder (eg, a crankpin) integrated with the work piece and carries out a round process while rotatably supporting a journal of a shaft or the like.
[0002]
[Prior art]
  In grinding of a cylindrical pin that is eccentric from the rotation axis at the time of machining, a rotational movement around the rotation axis (hereinafter sometimes referred to as “C-axis”) and a grinding wheel bed in the X-axis direction perpendicular to the C-axis By accurately synchronizing the translational movement of the cylindrical pin, the eccentric cylindrical pin can be ground into a highly accurate perfect circle.
  For example, when grinding a crank pin or the like of a crank shaft of a gasoline engine, in the finishing process for the crank pin (cylindrical pin), the grinding allowance of about 50 to 500 μm remaining at the end is ground by the above method. Sometimes.
[0003]
  In these eccentric cylindrical grindings, for example, when a cylindrical journal (crank journal) is gripped using a chuck having a gripping reference such as a V block, and the chuck is rotated around the C axis, grinding is performed. Therefore, in order to finish the cylindrical pin in a desired shape with high accuracy, it is necessary to accurately determine the position of the central axis of the cylindrical pin before finishing.
[0004]
  Therefore, in order to accurately determine the position of the central axis of the cylindrical pin, the relative position (eccentric direction) of the cylindrical pin with respect to the cylindrical journal and the radius of the cylindrical journal when it is gripped according to the gripping reference depend on the individual workpiece. Ingenuity has been made to prevent it.
  For example, conventionally, as a means for determining the eccentric direction (phase) of such a cylindrical pin, a method such as providing a workpiece with a groove or mark as a phase reference or using a phasing device is used. It has been.
  Further, in order to correctly fix the central axis of the cylindrical journal with respect to the C axis, a method of finishing the cylindrical pin after finishing the radius of the cylindrical journal to a specified value with high accuracy may be considered.
[0005]
[Problems to be solved by the invention]
  However, if the grinding machine is provided with the positioning device as described above, the manufacturing cost of the grinding machine increases accordingly.
  Further, if a groove or mark serving as a phase reference is provided in each workpiece, there arises a problem that the productivity of the workpiece is reduced by that amount.
  In addition, when it is not necessary to finish the cylindrical journal with the same level of precision as the cylindrical pin, the above method of finishing the radius of the cylindrical journal to the specified value with a high precision greatly reduces the productivity of the workpiece. There is a problem.
[0006]
  The present invention has been made to solve the above-described problems, and its purpose is to manufacture a cylindrical pin eccentric from the rotating shaft as described above at low cost or in a short time with high accuracy. It is to provide a cylindrical grinder capable of performing the above at a low cost.
[0007]
[Means for Solving the Problems]
  In order to solve the above problems, the following means are effective.
  That is, the first means is eccentrically formed with respect to a cylindrical journal supported so as to be rotatable around a rotation axis, and is integrally formed with the cylindrical journal, and grinds a cylindrical pin eccentric from the rotation axis by an eccentricity amount ε. In the cylindrical grinding machine, on the circumference of the cylindrical pinTopA sizing device for measuring the height h of the point p from the rotation axis, a rotation angle measuring means for measuring the rotation angle ψ relative to the rotation axis of the point p, and a circular circle of a cylindrical pin that gives the maximum value H of the height h Phase storage means for storing the rotation angle Ψ of the point P on the circumference with respect to the rotation axis, and the height S of the central axis of the cylindrical journal from the rotation axis(However, S ≠ 0), Rotation angle Ψ,And a given rated eccentricity E of the cylindrical pin with respect to the cylindrical journal.And an amount of eccentricity calculating means for calculating the amount of eccentricity ε based on the above, and a grinding data calculating means for calculating grinding data relating to the cylindrical pin based on the rotation angle Ψ and the amount of eccentricity ε.
[0008]
  Further, the second means is the above-described first means by the eccentric amount calculating means.,sideHeart volume εε = S cos Ψ ± ( E ² -S ² sin ² Ψ ) ^1/2 ByIt is to calculate.
[0009]
  Further, the third means obtains a correct solution corresponding to the eccentricity ε from the two different real solutions ε1 and ε2 with respect to the eccentricity ε calculated by the eccentricity calculating means in the second means. It is provided with the eccentric amount selection means to select based on.
[0010]
  Further, the fourth means is one of the first to third means described above, wherein the highest point giving the height h is p1, the rotation angle with respect to the rotation axis is ψ1, and integrally molded around the rotation axis When the cylindrical journal and the cylindrical pin are rotated, p1 is the highest point on the circumference of the cylindrical pin that is different from p1 and is the point p2 that gives the height h. In this state, the rotation angle with respect to the rotation axis is set to ψ2, and phase calculation means for calculating the rotation angle ψ based on the rotation angles ψ1 and ψ2 is provided.
  Note that the rotation shaft may be a rotation shaft.
  The above-described problems can be solved by the above means.
[0011]
[Operation and effect of the invention]
  FIG. 1 is a cross-sectional view of a workpiece on the xy plane showing the operation of the present invention. In general, the method of taking these coordinates is arbitrary, but for the sake of simplicity in FIG. 1, the upward direction in the vertical direction is the positive direction of the y axis, the xz plane is the height reference plane (h = 0), and the main axis Is assumed to be the z-axis.
  The definition of each symbol in this figure is as follows.
(Symbol definition)
      A ... Cylindrical pin or circumference of cylindrical pin cross section
      B ... Cylindrical journal or circumference of cylindrical journal cross section
      O_A... Points on the central axis of cylindrical pin A
      O_B... Points on the central axis of cylindrical journal B
      C ... Rotary axis during grinding or point on this rotary axis (C axis ≡ z axis)
      E ... Rated eccentric amount of cylindrical pin A relative to cylindrical journal B
      ε ... Eccentricity of cylindrical pin A from rotation axis C
      p ... Points on the circumference of the cylindrical pin A
                          (The highest point of the cylindrical pin A when measuring the height h)
      h ... Height of the point p from the rotation axis C (y coordinate of the point p)
      H ... Maximum value of height h
      P ... The point on the circumference of the cylindrical pin A that gives the maximum value H of the height h
      S: Height of the central axis of the cylindrical journal B from the rotation axis C
      ψ… rotation angle of point p with respect to rotation axis C
      Ψ ... rotation angle of point P with respect to rotation axis C
      φ ... Tilt angle of cylindrical pin A (side O_AO_BAngle from positive direction of y-axis)
      R ... Radius of cylindrical pin A before finishing
[0012]
  In this way, point O_BIf the cylindrical journal B is gripped so that is positioned on the y-axis, and then the workpiece is rotated clockwise around the rotation axis C, the height h of the point p is increased many times at any time during this rotation. By measuring, the rotation angle Ψ with respect to the rotation axis C of the point P giving the maximum value H of the height h can be obtained. Here, the rotation angle Ψ is a point O._BIs the angle measured counterclockwise with reference to (Ψ = 0).
[0013]
  At this time, triangle O_AO_BFor C, the following cosine formula holds:
[Expression 1]
  E²= Ε²+ S²-2εScosΨ (1)
  Therefore, when the equation (1) is solved for ε, the following equation (2) is obtained.
[Expression 2]
  ε = ScosΨ ± (E²-S²sin²Ψ)^1/2    ... (2)
[0014]
  Center axis O of cylindrical journal B_BThe height S from the rotation axis C is an amount that can be measured by a known three-point contact method or the like, as will be described in detail later.
  There are other methods for accurately obtaining the amount of eccentricity ε, as will be described later. For example, if the amount of eccentricity ε is obtained by measuring the rotational angle Ψ of the point P by the above method using Equation (2), The xy coordinate (x of the central axis of the cylindrical pin A_A, Y_A) Can be obtained by the following equation (3).
[Equation 3]
  x_A= Εcos (π / 2 + Ψ),
  y_A= Εsin (π / 2 + ψ) (3)
[0015]
  Therefore, in this way, the coordinates (x_A, Y_A) Can be accurately calculated, the grinding data relating to the cylindrical pin A can be calculated with high accuracy on the basis of these coordinates, so that the rotational movement around the rotation axis and the parallel movement movement of the grindstone in the x-axis direction It is possible to finish the cylindrical pin A into a desired shape by synchronizing them accurately.
[0016]
  For example, if the radius of the cylindrical pin A before finishing is R, and the width of the grinding allowance during finishing is δr (positive constant), the equation of the circumference of the cylindrical pin A ′ after finishing is given by Equation (3). The following equation (4) can be obtained.
[Expression 4]
  (Xx_A)²+ (Y−y_A)²= R²= (R-δr)²      (4)
  Here, r is a desired radius after finishing the cylindrical pin A.
[0017]
  In particular, the value of δr is set to a point O on the cross section (xy plane) of the cylindrical pin A._AIf the width of the grinding allowance is changed as a function of the angle η representing the radial direction δr (η), the non-circular workpiece can be ground. Is also possible.
  Needless to say, even if the rotating shaft is a rotating shaft, the same operation and effect as described above can be obtained.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present invention will be described based on specific examples.
(First embodiment)
  FIG. 2 is a hardware configuration diagram of the cylindrical grinding machine 100 of the present embodiment. In this embodiment, a right-handed orthogonal coordinate system is used in which the upward direction in the vertical direction is the positive direction in the y-axis direction. Therefore, the xz plane is a horizontal plane.
  On the bed 36 of the cylindrical grinding machine 100 installed on the horizontal floor surface, a table 40 that moves in the Z-axis direction by driving the motor 24 is provided.
[0019]
  The rotation amounts of the motors 24 and 28 are detected by the encoders 22 and 26, respectively. The table 40 is provided with a headstock 30 having a main shaft 31 and a tailstock 42 having a center 38, and a center 38 of the tailstock 42 and a chuck 32 provided at the tip of the main shaft 31 are used for machining. An object W is rotatably attached with the center of the main shaft as a rotation axis (C axis). The main shaft 31 rotates the workpiece W via the chuck 32 by driving the motor 28.
[0020]
  On the bed 36, a grindstone base 48 that moves in the X-axis direction by driving of a motor 54 is provided. The amount of rotation of the motor 54 is detected by the encoder 52. A grinding wheel 44 is provided on the side surface of the grinding wheel base 48, and the grinding wheel 46 (tool) disposed over the circumference of the grinding wheel 44 is rotated by driving the motor 50. A sizing device 70 is provided on the bed 36 so as to face the grinding wheel 44. The sizing device 70 moves in the X-axis direction and is used for measuring the outer diameter of the cylindrical portion of the workpiece W.
[0021]
  The numerical controller 10 includes a memory 1 (storage means), a CPU 2 (calculation means), and interfaces (I / F) 3 and 4. I / F4Mediates transmission / reception of data between the CPU 2 and the input / output device 12 including a keyboard and a display.
[0022]
  I / F3Intermediates data transmission / reception with the PLC 14, the amplifier 16, the grindstone head moving motor driving circuit 18, the table moving motor driving circuit 19 and the spindle motor driving circuit 20. The programmable logic controller (PLC) 14 controls the sizing device 70. The amplifier 16 amplifies the output of the sizing device 70 and performs A / D conversion.
[0023]
  The wheel head moving motor drive circuit 18, the table moving motor drive circuit 19, and the spindle motor drive circuit 20 amplify or servo-control each drive signal of the X axis, Z axis, and C axis (rotary axis). These drive circuits may be constituted by a servo control device incorporating a CPU.
[0024]
  In this way, the cylindrical grinding machine 100 is configured, and is eccentric by accurately synchronizing the rotational movement around the C axis (main axis) and the parallel movement of the grinding wheel head in the X axis direction perpendicular to the C axis. Eccentric cylindrical grinding of the cylindrical pin (workpiece W) is performed.
[0025]
  3 and 4 are sectional views of the chuck 60 of the present embodiment on the xy plane and the xz plane. A substantially U-shaped bracket 61 is attached to the chuck 32 supported by the end surface of the main shaft 31 via a face plate 32a. A V block 62 is connected in series in the z-axis direction to the recess 61a of the bracket 61. Two are mounted side by side. The sandwiching angle of the gripping reference surfaces 62a of the V block 62 facing each other is α (radian) (FIG.). A block 62b that contacts the end of the workpiece W and performs positioning in the z-axis direction is attached to the spindle 31 side of the V block 62.
[0026]
  On the side of the V block 62, an L-shaped clamp arm 64 that is rotatably supported by a pivot pin 63 is attached. A cylinder rod 66 of a cylinder 65 is attached to one end of the clamp arm 64 by a pin 66 a through a long hole 67, and the cylinder rod 66 is fixed to a piston 68.
[0027]
  When the cylinder 65 is actuated (rightward in the drawing), the clamp arm 64 is rotated counterclockwise around the rotation pin 63, and the workpiece W is pressed against the grip reference surface 62a of the V block and gripped. It rotates around the rotation axis C together with the main shaft.
[0028]
  FIG. 5 is a sectional view on the xy plane of the sizing device 70 of this embodiment. The sizing device 70 performs a sizing operation using a differential transformer mechanism, and is supported on the bed 36 so as to be able to advance and retract in the x-axis direction by a driving device (not shown). Reference numeral 71 denotes a main body of the sizing device 70, in which a mouth-shaped support member 71a is integrally supported.
[0029]
  The block 75 is supported by the pilot bar 77 via the linear motion bearing 76 so that the support member 71a can move up and down. A connecting shaft 78 is supported at a lower portion of the block 75 through the support member 71a and the main body 71, and a feeler 80 having a positioning surface 79 that contacts a positioning point of the workpiece W is supported on the connecting shaft 78. It is fixed.
[0030]
  As shown in FIG. 5, the feeler 80 has a positioning point (the highest point p on the outer periphery of the measuring object) when a measuring object (workpiece or the like) such as a cylindrical pin A rotates around the C axis. It is formed wide in the x-axis direction so as not to deviate from the positioning surface 79.
[0031]
  A connecting rod 82 is loosely fitted in the approximate center of the block 75 through a through hole 81, and a flange 83 is formed at the lower end of the connecting rod 82. The upper end of the connecting rod 82 is connected to a piston 84 in an air cylinder 72 provided on the upper portion of the main body 71.
[0032]
  block75Between the support member 71a and the block75A differential transformer 74 is provided that includes a core 74a made of a magnetic material supported on the core 74a and a differential coil 74b fixed to the support member 71a so as to surround the outer periphery of the core 74a.
[0033]
  The sizing device 70 detects the height of the highest point p of the measuring object such as the cylindrical pin A by the relative displacement between the core 74a and the differential coil 74b based on these configurations (differential transformer mechanism). Can do.
  If the sizing device 70 is further provided with a lower feeler 85 (broken line portion in FIG. 5), the sizing device 70 can measure the diameter of the cylinder.
[0034]
  FIG. 6 shows the central axis O of the cylindrical journal B_BIt is sectional drawing of the cylindrical journal B and the V block 62 showing the method of calculating | requiring the height S from the point C of FIG. Here, the distance from the C axis to the reference point G of the V block 62 is d, the radius of the cylindrical journal B is D, and the sandwiching angle of the gripping reference surface 62a is α. At this time, if the height Y of the cylindrical journal B from the point C is measured by the sizing device 70 as shown in FIG. 6, S and D can be obtained as the following equations (5) and (6). .
[0035]
[Equation 5]
  S = Y−D = (Y−d) / {1 + sin (α / 2)} + d
            = D / sin (α / 2) + d (5)
[Formula 6]
  D = (Y−d) sin (α / 2) / {1 + sin (α / 2)} (6)
[0036]
  Note that d is not necessarily a positive number, and this value depends on the specific configuration of the chuck 60. For example, if the point C is selected (arranged) so as to coincide with the reference point G of the V block 62, “d = 0” is obtained at this time, and the formula (5) is simplified.
  Further, for example, the center point O when the virtual reference journal M is gripped by the V block 62._MIf point C is selected (arranged) so that (center axis) and point C (C axis) coincide with each other, then “d = − | GO”_M| = −D0 / sin (α / 2) ”. Here, D0 is the radius of the reference journal M. Therefore, at this time, if ΔD≡ (D−D0), then S = ΔD / sin (α / 2), and Equation (5) can be written more simply.
[0037]
  As described above, as shown in FIG. 6 and equation (5), according to the cylindrical grinding machine 100 of this embodiment, the height S of FIG. 1 and equations (1) and (2) is measured by the sizing device 70. The height Y of the uppermost point of the cylindrical journal B can be obtained.
  The selection criteria for the double sign “±” in the formula (2) will be described below.
[0038]
  FIG. 7 is an xy plan view showing an appropriate range when the tilt angle φ of the cylindrical pin A is initially set in the present embodiment. Based on FIG. 1 and equation (2),
[Expression 7]
  a≡ScosΨ (7)
[Equation 8]
  b≡ (E²-S²sin²Ψ)^1/2             ... (8)
[Equation 9]
  Θ₀≡Ψ + π / 2 (9)
And define.
[0039]
  At this time, as can be seen from FIG. 7, equation (2) can be rewritten into the following equation (10).
[Expression 10]
  ε = ε1≡a + b (φ ≦ Θ₀),
  ε = ε2≡ab (φ ≧ Θ₀) …(Ten)
[0040]
  Therefore, as can be seen from FIG. 7, the following equation (11) is established.
## EQU11 ##
  0 <φ <π / 2 ⇒ ε = ε1 (11)
  That is, if the tilt angle φ of the cylindrical pin A is selected to be a positive value less than a right angle (initial setting), the eccentric amount ε from the rotation axis C of the cylindrical pin A at this time is the form of ε1 in the equation (10). Can be obtained at
[0041]
  Based on the above theory, the method of creating grinding data of the cylindrical pin A and grinding the cylindrical pin A into a desired shape will be exemplified below.
  8 and 9 are flowcharts showing a procedure for creating grinding data of the cylindrical pin A in the present embodiment. This flowchart is executed by the numerical controller 10 of FIG.
[0042]
  First, in step 705, the integer n and the maximum value H are initially set to zero. Next, in step 710, the center line L of the V block 62 is made to coincide with the y axis, and the rotation angle θ of the main axis (C axis) is initialized to zero. However, the rotation angle θ is an angle measured counterclockwise from the positive direction in the x-axis direction.
[0043]
  In step 715, the outer peripheral surface of the cylindrical journal B is brought into contact with the gripping reference surface 62a of the V block 62, and the cylindrical journal B is clamped so that the tilt angle φ of the cylindrical pin A becomes “0 <φ <π / 2”. The arm 64 is held and fixed. In step 717, the table 40 is moved by a predetermined amount, and the cylindrical journal B is positioned in front of the sizing device 70. In step 720, the sizing device 70 is moved forward by a predetermined amount so that the positioning surface 79 of the sizing device 70 is positioned above the cylindrical journal B, and preparation for measurement is made.
[0044]
  In step 725, the sizing device 70 measures the height Y of the cylindrical journal B shown in FIG. 6 or the equations (5) and (6).
  In step 730, the cylindrical pin A is positioned in front of the sizing device 70 by moving the table 40.
[0045]
  In step 735, the height h of the current highest point p on the circumference of the cylindrical pin A is measured by the sizing device 70. In step 740, if h <H, the process proceeds to step 760 in FIG. 9; otherwise, the process proceeds to step 745. In step 745, the values of the variable H and the variable n are updated. That is, the value of the variable H is changed to the latest measured value h, and the value of the variable n is increased by 1. In step 750, the main axis (C axis) is rotated clockwise by a small angle δθ (> 0), and the process returns to step 735.
[0046]
  In step 760 of FIG. 9, the rotation angle Ψ of the point P on the circumference of the cylindrical pin A that gives the maximum value H of the height h with respect to the main axis is stored in the memory 1 of the numerical controller 10 according to the following equation (12). (Phase storage means).
[Expression 12]
  Ψ = (n−1) δθ (12)
[0047]
  In step 765, the sizing device 70 is retracted. In step 770, the main axis is returned to the initial phase (θ = 0), and the rotation angle θ is reinitialized to “π / 2 + Ψ”. In step 775, the value of the eccentricity ε (= ε1) is obtained from the equations (5), (7), (8), (10), (12) (eccentricity calculating means).
[0048]
  In step 780, lift data (working shape data) of the cylindrical pin A is created by the equations (3) and (4) based on the values of ε and Ψ obtained above.
  The width δr of the grinding allowance in the equation (4) may be a function of the angle η representing the radial direction of the cylindrical pin A. In this way, it is also possible to carry out grinding of non-round workpieces.
[0049]
  In step 785, the rotational radius of the grindstone 46 is input from the input / output device 12. However, the turning radius of the grindstone 46 may be obtained by calculation from predetermined measurement data in this step. In Step 790, grinding data (Cx profile data) of the cylindrical pin A is created based on lift data (processed shape data) of the cylindrical pin A (grinding data calculation means) by a conventional technique.
[0050]
  That is, in Step 790, the relationship between the rotation angle θ of the main shaft reinitialized in Step 770 and the x coordinate of the rotation center of the grindstone 46, the rotation radius of the grindstone 46 obtained in Step 785, and the lift of the cylindrical pin A described above. A data format (Cx) for geometrically obtaining this relationship from data (machining shape data) and the like by a known conventional technique, and controlling the rotation angle θ of the C axis and the position coordinate x of the grindstone table 48 synchronously. Profile data format).
  In step 795, the cylindrical pin A is ground according to the grinding data of the cylindrical pin A.
[0051]
  If the above procedure is followed, the cylindrical pin A can be finished in a desired shape with high accuracy. Further, once the cylindrical journal B is gripped by the V block 62 according to the procedure of this embodiment, it is not necessary to grip the workpiece again until the grinding process of the cylindrical pin A is completed. Thereby, processing time can be shortened and productivity improves.
[0052]
  Further, if the cylindrical grinding machine 100 is configured as described above, it is not necessary to provide a positioning device for setting the phase in the grinding machine, and the manufacturing cost of the grinding machine can be reduced by that much. Further, it is not necessary to provide a phase reference groove or mark on each workpiece, and the productivity of the workpiece is improved accordingly.
[0053]
(Second embodiment)
  In the first embodiment, in steps 735 to 760, the rotation angle Ψ relative to the principal axis (C axis) of the point P on the circumference of the cylindrical pin A that gives the maximum value H of the height h is obtained by the equation (12). However, in the second embodiment, a method for obtaining the rotation angle Ψ with higher accuracy will be described.
[0054]
  FIG. 10 is a cross-sectional view of the cylindrical pin A showing the operation of the phase calculation means in the third means of the present invention, and the center point O of the cylindrical pin A_ARepresents a figure before and after the rotation operation of the cylindrical pin A, obtained by rotating clockwise around the point C (C axis) by θ1 + θ2.
  In FIG. 10, the points p1 and p2 are two points whose heights h1 and h2 are equal to each other when the point becomes the highest point of the cylindrical pin A. The rotation angles (phases) of the points p1 and p2 with respect to the C axis when the point p1 is the highest point of the cylindrical pin A are denoted by ψ1 and ψ2.
[0055]
  At this time, the heights h1 and h2 are given by the following equations (13) and (14) as can be seen from FIG.
[Formula 13]
  h1 = R + εcosθ1 (13)
[Expression 14]
  h2 = R + εcosθ2 (14)
[0056]
  Further, at this time, as can be seen from FIG. 10, the following equation (15) is established.
[Expression 15]
  h1 = h2⇔θ1 = θ2⇔β1 = β2⇔ψ = (ψ1 + ψ2) / 2
                                        (15)
  Therefore, if the phases ψ1 and ψ2 with respect to the C axis of the two points p1 and p2 as described above are obtained, the rotation angle ψ can be obtained in the form of the rightmost side of the equation (15) (phase calculation means).
[0057]
  In addition, when the equation (13) is differentiated once by θ1, the following equation (16) is obtained.
[Expression 16]
  dh1 / dθ1 = −εsinθ1 (16)
  Therefore, when h1 and ψ1 are measured in the vicinity of θ1 = π / 2, that is, in the vicinity of h1 = R, where | dh1 / dθ1 | has the maximum value, the rotational angle Ψ with the highest accuracy by the above method. Can be requested.
[0058]
(Third embodiment)
  In the first embodiment, ε = ε1 is guaranteed due to the constraint of “0 <φ <π / 2” in Expression (11). In the third embodiment, a method for obtaining the value of the eccentricity ε without imposing such restrictions will be described.
[0059]
  As can be seen from FIG. 1, the value of the eccentricity ε may be obtained by the following equation (17).
[Expression 17]
  ε = HR (17)
  However, H is the maximum value of the height h of the point p calculated | required in step 735-760 of 1st Example here. If the radius R of the cylindrical pin A before finishing is a known number, in step 775 of the first embodiment, the value of the eccentricity ε can also be obtained from this equation (17). In such a case, the solution of the eccentricity ε is uniquely determined.
[0060]
  Even if the radius R of the cylindrical pin A before finishing is unknown, if the radius R is measured by the sizing device 70 or the like, an accurate value of the eccentricity ε can be obtained from the equation (17). As shown in (3), the coordinates of the central axis of the cylindrical pin A before finishing (x_A, Y_A) Can be obtained accurately.
  Also in these cases, the action and effect of the present invention can be obtained.
[0061]
  Further, the third candidate value ε3 of the eccentricity ε is defined by the following equation (18) without measuring the value of the radius R of the cylindrical pin A before finishing, and two of ε1 and ε2 in the equation (10) are defined. A method of selecting a solution closer to ε3 as the true eccentricity ε from the solutions is also conceivable.
[Expression 18]
  ε3≡H-R0 (18)
  Here, R0 is the standard value (known number) of the radius of the cylindrical pin A before finishing.
[0062]
  Here, in order to select a solution closer to ε3 from the two solutions ε1 and ε2 in Equation (10), for example, the one having the smaller absolute value of the difference from ε3 or ε3 as a reference (denominator). It is sufficient to select the one with a ratio value closer to 1 (eccentricity selection means).
[0063]
  According to such a method, it is possible to obtain substantially the same operation and effect as in the first embodiment without imposing the constraint of “0 <φ <π / 2” in Expression (11).
[0064]
  However, when the value of b in Equation (8) is very small, or when the variation (standard deviation ΔR) of the radius R of the cylindrical pin A of each workpiece with respect to R0 is very large, the eccentricity ε Rather than using the above-mentioned eccentricity selection means using equation (18), it is better to obtain directly using equation (17).
  The eccentricity selection means of the third embodiment exhibits a great effect when the maximum value of | R−R0 | in all the workpieces before finishing is smaller than b or when ΔR << b.
[0065]
  In each of the above embodiments, the sizing device 70 of the cylindrical grinding machine 100 uses a differential transformer mechanism. However, the measurement principle and control method of these sizing devices are specific examples of the cylindrical grinding machine of the present invention. The specific configuration is not particularly limited to the above embodiment.
  That is, the cylindrical grinding machine of the present invention may be configured by arbitrarily combining known sizing devices and the like different from the above-described embodiments.
[0066]
  For example, in the above embodiment, the height S of the central axis of the cylindrical journal B is obtained from the equation (5) by the three-point contact chuck 32 using the V block 62. Even if the method is not used, the height S can be obtained by a known means using “S = Y−D”. Therefore, even if the V block is not provided, it is possible to obtain the operation and effect of the present invention by the means of the present invention.
[0067]
  In the first means of the present invention described above, the cylindrical grinder includes grinding data calculation means for calculating grinding data related to the cylindrical pin based on the rotation angle Ψ and the eccentricity ε. As a device to which the present invention is modified without any means, a sizing device that measures the height h of the point p on the circumference of the cylindrical pin from the rotation axis, and the rotation of the point p with respect to the rotation axis. If an apparatus comprising a rotation angle measuring means for measuring the angle ψ and a phase storage means for storing the rotation angle ψ with respect to the rotation axis of the point P on the circumference of the cylindrical pin giving the maximum value H of the height h is configured. Such an apparatus can be used as an initial phase detection apparatus for a workpiece.
[0068]
  Further, the above initial phase detector includes the height S of the central axis of the cylindrical journal from the rotation axis, the rotation angle Ψ, the maximum value H, the radius R of the cylindrical pin, or the inside of these S, Ψ, H, R. If an eccentricity amount calculating means for calculating the eccentricity amount ε based on the related value regarding at least one of the above is provided, such an apparatus can be used as a center position detecting device for the eccentric cylindrical pin.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view on a xy plane of a workpiece showing the operation of the present invention.
FIG. 2 is a hardware configuration diagram of a cylindrical grinding machine 100 according to an embodiment of the present invention.
FIG. 3 is a sectional view on an xy plane of a chuck 60 according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view on the xz plane of a chuck 60 according to an embodiment of the present invention.
FIG. 5 is a cross-sectional view on the xy plane of a sizing device 70 according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view of a cylindrical journal and a V block showing a method for obtaining the height S of the central axis of the cylindrical journal in the embodiment of the present invention.
FIG. 7 is an xy plan view showing an appropriate range at the time of initial setting of the tilt angle φ of the cylindrical pin in the embodiment of the present invention.
FIG. 8 is a flowchart (first half) showing a procedure for creating grinding data of a cylindrical pin in an embodiment of the present invention.
FIG. 9 is a flowchart (second half) showing a procedure for creating grinding data for a cylindrical pin in an embodiment of the present invention.
FIG. 10 is a cross-sectional view of a cylindrical pin showing the operation of the phase calculation means in the embodiment of the present invention.
[Explanation of symbols]
  100 ... Cylindrical grinding machine
    10: Numerical control device
    70 ... Sizing device
      A ... Cylindrical pin
      B ... Cylindrical journal
      C… Rotating shaft during grinding
      D ... Radius of cylindrical journal B
      E ... Rated eccentric amount of cylindrical pin A relative to cylindrical journal B
      ε ... Eccentricity of cylindrical pin A from rotation axis C
    O_A  ... Points on the central axis of cylindrical pin A
    O_B  ... Points on the central axis of cylindrical journal B
      p ... On the circumference of the cylindrical pin AToppoint
      h ... Height of p from rotation axis C
      H ... Maximum value of height h
      P ... The point on the circumference of the cylindrical pin A that gives the maximum value H of the height h
      S: Height of the central axis of the cylindrical journal B from the rotation axis C
      ψ… rotation angle of point p with respect to rotation axis C
      Ψ ... rotation angle of point P with respect to rotation axis C
      φ ... Cylinder pin A tilt angle
      R ... Radius of cylindrical pin A

Claims (4)

In a cylindrical grinder that grinds a cylindrical pin that is eccentrically formed with the cylindrical journal eccentrically with respect to a cylindrical journal that is rotatably supported around a rotating shaft, and is eccentric by an eccentric amount ε from the rotating shaft,
A sizing device for measuring a height h from the rotation axis of the uppermost point p on the circumference of the cylindrical pin;
A rotation angle measuring means for measuring a rotation angle ψ of the point p with respect to the rotation axis;
Phase storage means for storing a rotation angle Ψ of the point P on the circumference of the cylindrical pin that gives the maximum value H of the height h with respect to the rotation axis;
The eccentricity based on the height S (where S ≠ 0) of the central axis of the cylindrical journal, the rotational angle Ψ, and the rated eccentricity E of the cylindrical pin with respect to the cylindrical journal. An eccentricity calculating means for calculating the amount ε;
A cylindrical grinding machine, comprising grinding data calculation means for calculating grinding data relating to the cylindrical pin based on the rotation angle Ψ and the eccentric amount ε. The eccentric amount calculating means, the eccentric amount ε, ε = S cos Ψ ± (E 2 -S 2 sin 2 Ψ) cylindrical grinding machine according to claim 1, characterized in that calculated by ^1/2. There is provided an eccentricity amount selecting means for selecting a correct solution matching the eccentricity amount ε based on the maximum value H from two different real number solutions ε1 and ε2 for the eccentricity amount ε calculated by the eccentricity amount calculating means. The cylindrical grinding machine according to claim 2 , wherein: The most significant point giving the height h is p1, the rotation angle with respect to the rotation axis is ψ1,
When the integrally formed cylindrical journal and the cylindrical pin are rotated around the rotation axis, the point is different from the p1 and is the highest point on the circumference of the cylindrical pin and the height Phase rotation means for calculating the rotation angle ψ based on the rotation angles ψ 1 and ψ 2, where the rotation angle of the point p 2 giving the height h with respect to the rotation axis in the state where the p 1 is the highest point is ψ 2. The cylindrical grinding machine according to any one of claims 1 to 3, wherein the cylindrical grinding machine is characterized.

Images