Grinding machine centering gauge

Abstract

A workpiece centering gauge for a grinding machine includes a link having a first pivot configured to couple to the grinding machine, a first encoder to measure an angle of the link at the first pivot, a second pivot included in the link, a measuring fork configured to releasably contact an outer surface of an elongated workpiece, a surface feeler having a transducer included in the measuring fork to measure a workpiece diameter, and a second encoder to measure an angular position of the link relative to the measuring fork, wherein the angular position measured by the first encoder, the angular position measured by the second encoder, and the measured workpiece diameter are used to determine an offset of the elongated workpiece from a centerline.

Description

[Technical Field]

[0001]

[0001] This application relates to workpiece grinding, and more specifically to measuring the location of a workpiece using a grinding machine. [Background technology]

[0002]

[0002] Grinding machines can be used to shape the outer surface of elongated workpieces. For example, elongated workpieces such as crankshafts can be held in the headstock and tailstock. The elongated workpiece can be held and rotated while one or more grinding wheels are engaged with the outer surface of the workpiece to remove a specified amount of material and create a precisely shaped surface. The grinding process performed by the machine involves the precise positioning of both the elongated workpiece and the grinding wheel(s) and controlling the position of the grinding wheel relative to the surface of the workpiece to remove material and create the surface with very high precision. However, even with precise knowledge of the spatial positions of the grinding wheel(s) and the headstock and tailstock, some error may still exist. It is useful to implement a system that reduces this error. [Overview of the Initiative]

[0003]

[0003] In one implementation, a workpiece centering gauge for a grinding machine includes a link having a first pivot configured to connect to the grinding machine, a first encoder for measuring the angle of the link at the first pivot, a second pivot included in the link, a measuring fork configured to releasably contact the outer surface of an elongated workpiece, a surface feeler having a transducer included in the measuring fork for measuring the workpiece diameter, and a second encoder for measuring the angular position of the link relative to the measuring fork, wherein the angular position measured by the first encoder, the angular position measured by the second encoder, and the measured workpiece diameter are used to determine the displacement of the elongated workpiece from the centerline. In another implementation, a grinding machine having one or more grinding wheels includes a workpiece holder configured to releasably hold an elongated workpiece and to rotate the elongated workpiece about a longitudinal axis, and a workpiece centering gauge, the workpiece centering gauge including a link having a first pivot configured to connect to the grinding machine, a first encoder for measuring the angle of the link at the first pivot, a second pivot included in the link, a measuring fork configured to releasably contact the outer surface of the workpiece, a transducer included in the measuring fork for measuring the workpiece diameter, and a second encoder for measuring the angular position of the link relative to the measuring fork, the angular position measured by the first encoder, the angular position measured by the second encoder, and the workpiece diameter size are used to determine the displacement of the elongated workpiece from the center. [Brief explanation of the drawing]

[0004] [Figure 1]

[0004] This is a perspective view showing an implementation of a grinding machine having a workpiece centering gauge. [Figure 2]

[0005] This is a perspective view showing a portion of the implementation configuration of a grinding machine equipped with a workpiece centering gauge. [Figure 3]

[0006] This is another perspective view showing an implementation configuration of a grinding machine with a workpiece centering gauge. [Figure 4]

[0007] This is another perspective view showing a portion of the implementation configuration of a grinding machine having a workpiece centering gauge. [Figure 5]

[0008] This is a partially exploded view showing the mounting configuration of a workpiece centering gauge. [Figure 6]

[0009] This is a side view showing the mounting configuration of the workpiece centering gauge. [Figure 7]

[0010] This is another side view showing the mounting configuration of the workpiece centering gauge. [Figure 8]

[0011] This is a mathematical diagram showing the measurements determined by the implementation of the workpiece centering gauge. [Figure 9]

[0012] This is another side view showing the mounting configuration of the workpiece centering gauge. [Modes for carrying out the invention]

[0005]

[0013] A grinding machine may include a workpiece centering gauge comprising a link section mounted in a fixed location, with a measuring fork attached to its distal end. The measuring fork includes a surface feeler having a transducer for determining the workpiece size. The workpiece centering gauge includes at least one link, a measuring fork, a surface feeler, and at least two pivotable joints, each joint having an integrated encoder. For example, the workpiece centering gauge may include a first pivot fixedly mounted to the grinding machine at one end of the link. A second pivot located at the distal end of the link may be pivotably mounted to the measuring fork, which touches the surface of the workpiece to determine the actual location of the workpiece centerline. Using its multiple encoders and surface feeler, the workpiece centering gauge can determine the actual size of the workpiece and the actual centerline of the workpiece in an axial location with very high precision. A workpiece centering gauge can measure the size of a workpiece at an axial location using a surface feeler, determine the relative angle at each encoder using the actually measured size, and, given the determined angle, the measured workpiece size, and a known length of the link, calculate the polar coordinates of the workpiece centerline. After measuring the workpiece size, the workpiece centering gauge can determine the position off the workpiece centerline. The link may also be configured to move around a pivot in a single plane of motion.

[0006]

[0014] Determining the actual location of the workpiece centerline using a measured workpiece surface can be particularly useful when grinding larger, elongated workpieces that may have a tendency to flex or change shape slightly while the headstock and tailstock of the grinding machine are engaged. For example, for crankshafts larger than 1.5 meters (m), a work rest may be used to support one or more sections of the crankshaft between the headstock and tailstock to prevent the crankshaft from flexing or exhibiting an unideal shape. That is, while a grinding machine can be programmed using the theoretical location of the workpiece centerline, the theoretical location may differ from the actual location of the workpiece centerline by a considerable amount, especially with respect to larger, elongated workpieces. For example, the theoretical and actual locations may differ by more than 2 millimeters (mm). The actual location of the workpiece centerline can be compared to the theoretical or desired location of the workpiece centerline, and the work rest can be mechanically adjusted along the three axes to support the workpiece so that the workpiece centerline, and therefore the workpiece surface, is positioned at the theoretical or desired location, thereby compensating for any flexing or distortion. While some embodiments of this specification are described with reference to a crankshaft, it should be understood that the disclosures herein are equally applicable to other elongated workpieces.

[0007]

[0015] Figures 1 to 4 show a grinding machine 10 including a workpiece centering gauge 12 for measuring the spatial location of the workpiece surface. In this embodiment, the grinding machine 10 is an orbital grinding machine designed to grind the outer surface of a crankshaft workpiece. More specifically, the orbital grinding machine can use one or more grinding wheels 14 to create journal surfaces and crankpin surfaces on the crankshaft 16. In this configuration, the orbital grinding machine 10 can accommodate small crankshafts of about 1.5 meters (m) and long crankshafts of about 12 meters. Such configurations of the grinding machine 10 include the Fives Landis LT2HHe or LT3e orbital crankshaft grinding machines. However, in other embodiments using different types of workpieces or grinding machines, positioning gauges can be used to determine the position of the workpiece surface.

[0008]

[0016] The orbital grinding machine 10 may include a workpiece holder 18 having a headstock 20 and a tailstock 22, a grinding wheel assembly 24 including a spindle assembly 26 connected to a grinding wheel 14, and a machine bed 28. The machine bed 28 may be a relatively flat structure placed on the floor and supporting the elements of the grinding machine 10. For example, the machine bed 28 may support the headstock 20 and tailstock 22 on its surface, thereby allowing the crankshaft 16 to engage with both the headstock 20 and tailstock 22 and be raised above the bed 28. The machine bed 28 may be rectangular such that its length along the Z-axis is longer than its length along the X-axis. One or more grinding wheel rails 30 may extend along the surface of the machine bed 28 along the Z-axis to facilitate the movement of the grinding wheel assembly 24 along the Z-axis, thereby allowing the grinding wheel assembly 24 to slide or roll along the rails 30 in any direction to position the grinding wheel at a specific axial point along the X-axis. The grinding wheel assembly can be moved along the Z-axis on the rail 30 using a linear servo motor, and an optical scale may be used to determine the position of the grinding wheel 14 along the X-axis.

[0009]

[0017] One or more workpiece holder rails 32 may be spaced apart from the grinding wheel rail 30, positioned on the opposite side of the grinding wheel rail 30 on the machine bed 28, and extending along the Z-axis. The headstock 20 and tailstock 22 may slide or roll along the workpiece holder rails 32 to accommodate crankshafts of different axial lengths, respectively, and engage the head and tail of the crankshaft 16 with workpiece holders 34 such as chucks or collets, thereby holding the crankshaft 16 in a specific position. Each of the workpiece holders 34 of the headstock 20 and tailstock 22 may include an electric motor that can jointly and coordinately rotate the crankshaft 16 in any angular direction within a 360-degree range of motion around its longitudinal axis (C). Rotary encoders may be used in the headstock 20 and tailstock 22 to determine the angular position of the crankshaft 16. The headstock 20 and tailstock 22 may each be moved individually along the Z-axis using a servo motor and a rack drive.

[0010]

[0018] The grinding wheel assembly 24 may include a base 36 mounted on a grinding wheel rail 30. The spindle assembly 26 may be supported by the base 36 so as to be movable along the z-axis on the grinding wheel rail 30, and includes a grinding wheel 14 connected to the spindle assembly 26, one or more feed rails 40 between the base 36 and the spindle assembly 26, a linear servo motor, an optical scale, and a workpiece centering gauge 12. The spindle assembly 26 may include a spindle drive motor that pivots the spindle shaft and ultimately rotates the grinding wheel 14 connected to the spindle shaft. The grinding wheel 14 may have a radial surface 44 that contacts the crankshaft 16 and faces outward from the spindle shaft rotation axis (α). The spindle drive motor may be concentric with the spindle shaft so that the rotor of the spindle drive motor 46 is connected to the spindle shaft and the stator is concentric with the rotor. Front and rear bearings are positioned at both ends of the spindle shaft to provide support during operation. The bearings may be implemented as hydrostatic bearings. A rotary encoder 58 may be mounted at the distal end of the spindle shaft 48 to determine the angular position, velocity, or acceleration of the spindle shaft 48 and the grinding wheel 14. The feed rail 40 may extend along the X-axis and be positioned perpendicular to the grinding wheel rail 30.

[0011]

[0019] The spindle assembly 26 can slide along the feed rail 40 along the X-axis, moving closer to or away from the crankshaft 16. The linear motor can move the grinding wheel assembly 24 along the X-axis on the feed rail 40 using an encoder that specifies the position of the grinding wheel assembly 24 along the X-axis.

[0012]

[0020] One or more work rest assemblies 70 may be positioned below the crankshaft 16 to support it and prevent deformation of the crankshaft 16. As described above, longer crankshafts (e.g., >1.5m) held between the headstock 20 and the tailstock 22 may deform or flex due to the effects of gravity, temperature, or other environmental factors. The work rest assemblies 70 may be positioned below the crankshaft 16 to prevent flexing or deformation. The work rest assemblies 70 may be positioned in the XZ plane at a desired point below the crankshaft 16 and may be height-adjustable in the XY plane using a servo motor controlled based on the actual determination of the workpiece centerline to engage with the crankshaft 16 and position the crankshaft 16 at a specified height. In this way, the work rest assemblies 70 may be adjustable along three axes. The work rest assemblies 70 may include adjustable arms that can be moved closer to or further away from each other to engage with the outer surface of the crankshaft 16. The arms are adjustable to accommodate different diameters and shapes of the crankshaft 16. The work rest assembly 70 may be positioned to engage with the crankpin of the crankshaft 16. For example, the work rest assembly 70 can slide along rails on the machine bed 28 that extend in the X and Z directions. In some implementations, the rails may have an inverted dovetail cross-sectional shape. That is, the machine bed 28 may include elongated mortise slots that receive tenons contained in the work rest assembly 70. The work rest assembly 70 can slide along the surface of the machine bed 28 within the slots.

[0013]

[0021] Referring to FIGS. 5-9, an implementation form of a workpiece centering gauge 12 that can be carried by a grinding machine 10 is shown. In this implementation form, the workpiece centering gauge 12 includes a first pivot 58, a first encoder 60 coaxial with the first pivot 58, a second pivot 62, and a second encoder 64 coaxial with the second pivot 62. The workpiece centering gauge 12 may be attached to the grinding wheel assembly 24 at the first pivot 58 connected to the link 66. The link 66 may be an elongated member extending away from the grinding machine 10 and is attached to the measuring fork 68 at the second pivot 62 at the distal end of the link 66. The measuring fork 68 can include a V-shaped end having two opposing planes that releasably engage the outer surface of the crankshaft 16.

[0014]

[0022] The measuring fork 68 may include a surface feeler 100 for measuring the workpiece diameter and optionally the workpiece surface shape. The surface feeler 100 may include a piston 102 slidably received by the measuring fork 68. The piston 102 may be biased toward the crankshaft 16 toward away from the measuring fork 68 by a spring or other biasing member. The piston 102 may be operably engaged with a transducer for measuring the linear movement of the piston 102 relative to the measuring fork 68. When the measuring fork 68 moves and engages with a surface of the crankshaft 16, such as a main bearing, the piston 102 engages with the workpiece surface and slides linearly relative to the measuring fork 68, overcoming the spring force until its plane contacts the crankshaft 16. The transducer can communicate to the computer processor 74 the amount of linear movement of the piston 102 relative to the measuring fork 68 from the moment the piston 102 contacts the crankshaft 16 until the plane contacts the workpiece surface and the piston 102 stops moving relative to the measuring fork 68. The surface feeler 100 can provide the grinding machine 10 with an actual measurement of the diameter of the crankshaft 16 at a given point, such as the main bearing. It is also possible to rotate the crankshaft 16 at this point while the piston 102 and the measuring fork 68 are engaged with the workpiece surface. The movement of the piston 102 relative to the measuring fork 68 can be monitored to determine the surface shape of the crankshaft 16.

[0015]

[0023] The movement of the link 66 and the measuring fork 68 can be achieved using various mechanisms such as a linear piston. For example, a link piston 70 may be pivotally attached to the grinding wheel assembly 24 and the link 66. As the length of the link piston 70 extends, the angular position of the link 66 can change relative to the grinding wheel assembly 24 about the first pivot 58. The first encoder 60 can detect the angular position of the link 66 relative to the first pivot 58. The term "piston" can be broadly interpreted as any linear actuator such as a ball screw or a hydraulic piston, but other mechanical mechanisms for moving the link 66 and the measuring fork 68 are possible. For example, the first pivot 58 and the second pivot 62 can use a stepper motor to move the link 66 and the measuring fork 68 relative to the grinding wheel assembly 24. A fork limit rod 72 may be pivotally attached to the grinding wheel assembly 24 and the measuring fork 68. When the measuring fork 68 is moved towards the crankshaft 16, the angular position of the measuring fork 68 relative to the second pivot 62 can be limited. The second encoder 64 can detect the angular position of the measuring fork 68 relative to the second pivot 62.

[0016]

[0024] After the link 66 and measuring fork 68 are moved around pivots 58, 62 and engage with the outer surface 76 of the crankshaft 16, and the diameter of the crankshaft 16 is measured, the workpiece centering gauge 12 can measure the relative angles at and between pivots 58, 62 using a first encoder 60 and a second encoder 64. Several different types of encoders can be used to implement the first encoder 60 or the second encoder 64. The workpiece centering gauge 12 may be calibrated by placing a master diameter on the workpiece holder 18 at the centerline of the workpiece. The measuring fork 68 can engage with the outer surface of the master diameter to provide known data points while the first encoder 60 measures the angle and the second encoder 64 measures the angle. Data from the surface feeler 100 when the surface feeler 100 contacts the master diameter may be combined with the measured angle by the gauge 12 to determine the diameter of the master diameter. The angle determined by the first encoder 60 and the second encoder 64 while the measuring fork 68 is engaged with the master diameter allows the gauge 12 to be calibrated relative to the workpiece centerline. If the calculated diameter or centerline of the master diameter does not match a known diameter or centerline, the gauge 12 may be adjusted to ensure high accuracy in future measurements. In one implementation, a Heidenhain type ECN413 encoder can be used. The measured angle may be used in conjunction with the known lengths of the link 66 and the measuring fork 68, as well as the dimensions of the measuring fork 68, to determine the actual center of the crankshaft 16. In other implementations, it is possible to use more than two pivots and more than two encoders.

[0017]

[0025] The actual center of the crankshaft 16 can be calculated using the following variables shown in Figure 8 and the formula detailed below.

[0018]

[0026] The constants used in these calculations are as follows: P(X,Y) - First pivot point having the X-axis at the measurement position Length of the link from P to P' in L1 L , ,

[0029] , 22 , , 21 , OP , , , , 21 , 22 - Length of the virtual upper sub - arm L 22 - L 21 Length of the virtual second sub - arm from L to the gauge V - intersection V - Included angle of the V - shape of the measuring fork XI(ξ) - L selected to be 90 degrees 21 ]and L 22 The angle between them

[0019]

[0027] Even if the surface feeler is not located at the center of the measuring fork 68, these calculations are based on the fact that the centers of workpieces with various diameters pass through the line defined by the center of the V - shape.

[0020]

[0028] The variables provided by the two encoders and the surface feeler are as follows. Gamma1(γ1) - Angle from the X - axis (horizontal) to the first arm Gamma4(γ4) - Angle from the first arm to L 21 to C - Workpiece radius L - Dimension from the workpiece center to the gauge V - intersection L OP - Distance from P' to the workpiece center O Gamma3(γ3) - Angle between the first arm and the hypotenuse (L OP ) from P' to the workpiece center

[0021]

[0029] The center of a workpiece such as the crankshaft 16 can be derived as a series of three conversions from polar coordinates to rectangular coordinates. L = C / Sin(V / 2) [[ID=​​​​​​​​​​​​​​ P' = X1 - L1*Cos(γ1), Y1 + L1*Sin(γ1), defined as X2 and Y2. O = X² + L OP *Cos(-γ1-γ3),Y2-Sin Cos(-γ1-γ3)

[0022]

[0030] An example is given below of how the deviation of the crankshaft centerline (O) can be determined using the first pivot 58, the first encoder 60, the second pivot 62, and the second encoder 64, the known length (l) of the link 66, the known dimensions of the measuring fork 68, and the measured diameter of the crankshaft 16. The crankshaft 16 can extend along the Z-axis, and the center (O) of the crankshaft 16 may be given a theoretical location of (0,0), which indicates that the center is not offset from the Z-axis in either the X-axis or the Y-axis. Given this theoretical location of the centerline of the crankshaft 16, the workpiece centering gauge 12 can be moved to contact a location along the outer surface 76 of the crankshaft 16. The link piston 70 and the fork limiting rod 72 can lower the link 66 and the measuring fork 68 so that the fork 68 contacts the outer surface of the crankshaft 16. In one example, several theoretical calculation values ​​may be determined. For example, the distance between the first pivot 58 and the second pivot 62 may be 350 mm, and the theoretical distance between the second pivot 62 and the theoretical center (O) of the crankshaft 16 may be 291.9634 mm. The diameter of the crankshaft 16 at the location where the measuring fork 68 contacts the crankshaft surface may be specified as 181.275 mm. The angle (a) at the first pivot 58 using the first encoder 60 may be 180 degrees, and the theoretical angle (b) of the second pivot 62 using the second encoder 64 may be 270 degrees (as measured on the coordinate plane). The theoretical distance from the contact point of the measuring fork 68 to the second pivot 62 may be 206.4493 mm.

[0023]

[0031] Given the above values, the distance from the centerline (O) of the crankshaft 16 to the first pivot 58 can be determined. In this example, it may be 555.4516566 mm. A triangular relationship may exist between the first pivot 58, the second pivot 62, and the centerline of the crankshaft 16. The angle (a') of the triangle at the first pivot 58 may be calculated as 49.62084375 degrees, and the angle (b') of the triangle at the second pivot 62 may be calculated as 90.98928877 degrees. The angle (c') of the centerline of the crankshaft 16 with respect to the first pivot 58 and the second pivot 62 may be calculated as 39.38986749 degrees.

[0024]

[0032] The theoretical values ​​may be used as calibration standards and, given known dimensions of the link 66 and measuring fork 68, be compared with values ​​derived from actual angle measurements taken using the first encoder 60, the second encoder 64, and the surface feeler 100. In this example, the first encoder 60 can measure an angle (a) of 179.9869221 degrees, and the second encoder 64 can measure an angle (b) of 270.98928877 degrees. These angles differ from the theoretical angles of 180 and 270 degrees. Using the angles recorded by the first encoder 60 and the second encoder 64, the displacement of the location of the center (c) of the crankshaft 16 may be calculated as 0.0033 mm in the vertical (Y) direction and -0.0039 mm in the horizontal (X) direction. This is one example of how these calculations can be performed, and other methods are possible.

[0025]

[0033] The computer processor 74 can provide input to and receive feedback from several of the components identified above. For example, the movement of the machine bed 28 along the grinding wheel rail 30, the movement of the grinding wheel assembly 24 along the feed rail 40, the operation of the spindle shaft 48, and / or the servo motors controlling the electric motors of the headstock 20 and tailstock 22, as well as the first encoder 60 and the second encoder 64, can all receive input signals from the computer processor 74, such as commanded motor speed and direction, and can also provide output signals to the computer processor 74, such as actual angular position, angular shaft speed, and / or angular direction. The workpiece centering gauge 12 can provide the computer processor 74 with an output in the form of a signal indicating its position in the first encoder 60 or the second encoder 64. The computer processor 74 may be any type of device capable of processing electronic instructions, including a microprocessor, microcontroller, host processor, controller, and application-specific integrated circuit (ASIC). It may be a dedicated processor used solely for performing the described method, or it may be shared with other functions performed by the grinding machine 10. The computer processor 74 executes various types of digital storage instructions, such as software or firmware programs stored in computer-readable memory. However, it should be understood that other implementations are possible in which at least some of these elements can be implemented together on a printed circuit board.

[0026]

[0034] It should be understood that the above is a description of one or more embodiments of the present invention. The present invention is not limited to any specific embodiment(s) disclosed herein, but rather is defined solely by the following claims. Furthermore, the descriptions contained herein should not be construed as definitions of terms used in the claims or limitations on the scope of the present invention, except where such terms or phrases are expressly defined above with respect to a particular embodiment. Various other embodiments and various variations and modifications of the disclosed embodiments(s) will be apparent to those skilled in the art. All such other embodiments, variations and modifications are intended to fall within the scope of the appended claims.

[0027]

[0035] When used herein and in the claims, the terms “e.g.”, “for example,” “for instance,” “such as,” and “like,” as well as the verbs “comprising,” “having,” and “including,” and their other verbal forms, should each be interpreted as open-ended when used in conjunction with a list of one or more components or other items, meaning that the list should not be considered to exclude any other additional components or items. Other terms should be interpreted in their broadest and most reasonable sense unless used in a context requiring a different interpretation. The invention described in the original claims of this application is listed below. [1] A workpiece centering gauge for a grinding machine, A link having a first pivot configured to connect to the grinding machine, A first encoder for measuring the angle of the link at the first pivot, The second pivot included in the aforementioned link, A measuring fork configured to releasably contact the outer surface of an elongated workpiece, and a surface feeler having a transducer included in the measuring fork for measuring the diameter of the workpiece, A second encoder for measuring the angular position of the link relative to the measuring fork, Equipped with, A workpiece centering gauge is used to determine the displacement of the elongated workpiece from the center line, using the angular position measured by the first encoder, the angular position measured by the second encoder, and the measured workpiece diameter. [2] The workpiece centering gauge according to [1], further comprising a link piston connected at one end to the grinding machine and at the other end to the link, for moving the link relative to the grinding machine. [3] The workpiece centering gauge according to [1], further comprising a fork limiting rod connected at one end to the link and at the other end to the measuring fork, for limiting the angular movement of the measuring fork. [4] A workpiece centering gauge as described in [1], in which polar coordinates are calculated and then converted to Cartesian coordinates. [5] The elongated workpiece is a crankshaft, as described in [1]. [6] The workpiece centering gauge according to [1], wherein a master diameter is mounted on the grinding machine, the measuring fork engages with the outer surface of the master diameter, the angle is measured by a first encoder, and the angle is measured by a second encoder. [7] The elongated workpiece is 1.5 meters (m) or longer, as described in [1], for the workpiece centering gauge. [8] A grinding machine comprising one or more grinding wheels, A workpiece holder configured to hold an elongated workpiece in a releaseable manner and to rotate the elongated workpiece about its longitudinal axis, Workpiece centering gauge and The workpiece centering gauge is equipped with, A link having a first pivot configured to connect to the grinding machine, A first encoder for measuring the angle of the link at the first pivot, The second pivot included in the aforementioned link, A measuring fork configured to releasably contact the outer surface of a workpiece, A transducer included in the measuring fork for measuring the diameter of the workpiece, A second encoder for measuring the angular position of the link relative to the measuring fork, A grinding machine in which the angular position measured by the first encoder, the angular position measured by the second encoder, and the workpiece diameter size are used to determine the displacement of the elongated workpiece from the center. [9] The grinding machine according to [8], further comprising a link piston connected at one end to the grinding machine and at the other end to the link, for moving the link relative to the grinding machine.

[10] The grinding machine according to [8], further comprising a fork limiting rod connected at one end to the link and at the other end to the measuring fork, for limiting the angular movement of the measuring fork.

[11] A grinding machine as described in [8], wherein polar coordinates are calculated and then converted to Cartesian coordinates.

[12] The grinding machine described in [8], wherein the elongated workpiece is a crankshaft.

[13] The grinding machine according to [8], wherein the elongated workpiece is 1.5 meters (m) or longer.

Claims

1. A workpiece centering gauge for grinding machines, A link having a first pivot configured to connect to the grinding machine, A first encoder for measuring the angular position of the link at the first pivot, The second pivot included in the aforementioned link, A measuring fork including a surface feeler configured to releasably contact the outer surface of an elongated workpiece held in a workpiece holder of the grinding machine having a headstock and a tailstock, A transducer for measuring the linear movement of a piston, which is included in the measuring fork used for measuring the diameter of a workpiece and is slidably received with respect to the measuring fork, A second encoder for measuring the angular position of the link relative to the measuring fork, Equipped with, The actual center of the workpiece can be determined using the following constants: P(X,Y) - First pivot point having the X-axis at the measurement position L １ - Length of the link from P to P' L ２１ - Length of the virtual upper sub-arm L ２２ - L ２１ The length of the virtual second sub-arm from the gauge V-shaped intersection point. V - The angle of the V-shape of the measuring fork XI(ξ) -L ２１ and L ２２ angle between Gamma 1 (γ1) - Angle from the X-axis (horizontal) to the first arm Gamma 4 (γ4) - From the first arm to L ２１ up to angle C - Work radius L - Dimension from the center of the workpiece to the V-shaped intersection of the gauge. L ＯＰ - Distance from P' to the center O of the workpiece Gamma 3 (γ3) - The included angle between the first arm and the hypotenuse (L ＯＰ ) from P' to the center of the workpiece A series of three polar coordinates are calculated, and then converted to Cartesian coordinates using the following formula: L=C / Sin(V / 2) LOP=SQRT(L21^2+(L22+L)^2) γ3=γ4-Atan((L22+L) / L21)) P = X1, Y1 P' = X1 - L1*Cos(γ1), Y1 + L1*Sin(γ1), defined as X2 and Y2. O=X2+LOP*Cos(-γ1-γ3), Y2-Sin Cos(-γ1-γ3) Given a theoretical location where the centerline of the workpiece is not offset from the Z axis in both the X and Y axes, a workpiece centering gauge is moved to contact a location along the outer surface of the workpiece, and the angular position measured by the first encoder, the angular position measured by the second encoder, and the measured workpiece diameter are used to determine the deviation of the elongated workpiece at the measurement location from the centerline of the workpiece.

2. The workpiece centering gauge according to claim 1, further comprising a link piston connected to the link at one end to the grinding machine and at the other end to move the link relative to the grinding machine.

3. The workpiece centering gauge according to claim 1, further comprising a fork limiting rod connected at one end to the link and at the other end to the measuring fork, for limiting the angular movement of the measuring fork.

4. The workpiece centering gauge according to claim 1, wherein the elongated workpiece is a crankshaft.

5. The workpiece centering gauge according to claim 1, wherein a master diameter is mounted on the grinding machine, the measuring fork engages with the outer surface of the master diameter, the angular position is measured by the first encoder, and the angular position is measured by the second encoder.

6. The workpiece centering gauge according to claim 1, wherein the elongated workpiece is 1.5 meters (m) or longer.

7. A grinding machine comprising one or more grinding wheels, A workpiece holder configured to hold an elongated workpiece in a releaseable manner and to rotate the elongated workpiece about its longitudinal axis, Workpiece centering gauge and The workpiece centering gauge is equipped with, A link having a first pivot configured to connect to the grinding machine, A first encoder for measuring the angular position of the link at the first pivot, The second pivot included in the aforementioned link, A measuring fork including a surface feeler that contacts the outer surface of a workpiece, configured to releasably contact the outer surface of the workpiece, A transducer for measuring the linear movement of a piston, which is included in the measuring fork used for measuring the diameter of a workpiece and is slidably received with respect to the measuring fork, A second encoder for measuring the angular position of the link relative to the measuring fork, Includes, The actual center of the workpiece can be determined using the following constants: P(X,Y) - First pivot point having the X-axis at the measurement position L １ - Length of the link from P to P' L ２１ - Length of the virtual upper sub-arm L ２２ - L ２１ The length of the virtual second sub-arm from the gauge V-shaped intersection point. V - The angle of the V-shape of the measuring fork XI(ξ) -L ２１ and L ２２ angle between Gamma 1 (γ1) - Angle from the X-axis (horizontal) to the first arm Gamma 4 (γ4) - From the first arm to L ２１ up to angle C - Work radius L - Dimension from the center of the workpiece to the V-shaped intersection of the gauge. L ＯＰ - Distance from P' to the center O of the workpiece Gamma 3 (γ3) - The hypotenuse (L) from the first arm and P' to the center of the workpiece ＯＰ ) the angle between A series of three polar coordinates are calculated and then converted to Cartesian coordinates using the following formula: L=C / Sin(V / 2) LOP=SQRT(L21^2+(L22+L)^2) γ3=γ4-Atan((L22+L) / L21)) P = X1, Y1 P' = X1 - L1*Cos(γ1), Y1 + L1*Sin(γ1), defined as X2 and Y2. O=X2+LOP*Cos(-γ1-γ3), Y2-Sin Cos(-γ1-γ3) A grinding machine in which, given a theoretical location where the centerline of the workpiece is not offset from the Z axis in both the X and Y axes, a workpiece centering gauge is moved to contact a location along the outer surface of the workpiece, and the angular position measured by the first encoder, the angular position measured by the second encoder, and the workpiece diameter are used to determine the deviation of the elongated workpiece from the centerline at the measurement location.

8. The grinding machine according to claim 7, further comprising a link piston connected to the grinding machine at one end and to the link at the other end, for moving the link relative to the grinding machine.

9. The grinding machine according to claim 7, further comprising a fork limiting rod connected at one end to the link and at the other end to the measuring fork, for limiting the angular movement of the measuring fork.

10. The grinding machine according to claim 7, wherein the elongated workpiece is a crankshaft.

11. The grinding machine according to claim 7, wherein the elongated workpiece is 1.5 meters (m) or longer.

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