Machining device

Abstract

To provide a machining device that eliminates the need for dedicated work or setup for measurement for each workpiece having a different machining dimension, and that also allows measurement of an eccentric circular portion or a non-circular portion eccentric from the rotation center of the workpiece.SOLUTION: A machining device that machines a workpiece with machining means and is numerically controlled includes storage means 70, control means 80, and a measuring device 10 that measures a dimension in the radial direction of the workpiece. The measuring device 10 includes a pair of measuring heads 30a, 30b that sandwich the workpiece, and measuring head adjustment means 20 that adjusts positions of the pair of measuring heads 30a, 30b. The control means 80 utilizes machining data 72 being input data for machining the workpiece, and controls the measuring head adjustment means 20 to move the pair of measuring heads 30a, 30b to positions where the workpiece can be measured.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus equipped with a measuring device for measuring the radial dimension of a workpiece. [Background technology]

[0002] In machining equipment such as grinders and lathes, sizing devices are used to measure the dimensions of the machined portion of a workpiece. A known sizing device has a structure in which the workpiece is sandwiched between a pair of measuring probes. For example, Patent Document 1 discloses a sizing device that adjusts and sets the distance between a fixed measuring probe and a movable measuring probe so that it moves and measures within a predetermined dimensional range depending on the outer diameter of the workpiece to be measured. The sizing device described in Patent Document 1 significantly expands the measurement range, making it possible to measure with high precision the machined diameters of various workpieces, from small diameters to large diameters, which could not be measured with conventional devices.

[0003] Measurements using a sizing device are relative measurements to the measurement standard of the machined part of the workpiece. When a master workpiece is used to set the measurement standard, the master workpiece is sandwiched between a pair of measuring probes, and the position of the measuring probes at this time is set as the measurement standard. When measuring the dimensions of a machined workpiece, deviations from the measurement standard are detected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 52-41515 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as mentioned above, measurements using a sizing device are relative to a measurement standard, so the measurement standard dimension must be set in advance, and dedicated work and setup are required for measurements for each workpiece with different machining dimensions. Furthermore, even if the measurement target is a circular part, if the circular part is eccentric from the center of rotation of the workpiece or if the measurement target is a non-circular part, the number of parts to be measured increases, so the work of setting the measurement standard dimension is time-consuming.

[0006] The present invention solves the above-mentioned conventional problems, and aims to provide a processing device that eliminates the need for dedicated measurement work and setup for each workpiece with different processing dimensions, and is also capable of measuring eccentric circular parts (with a cross-sectional shape that is a perfect circle) and non-circular parts (with a cross-sectional shape that is not a perfect circle) that are eccentric from the center of rotation of the workpiece. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the processing apparatus of the present invention is a numerically controlled processing apparatus that processes a workpiece using a processing means, and is equipped with a memory means, a control means, and a measuring device that measures the radial dimensions of the workpiece, and the measuring device is equipped with a pair of measuring heads that sandwich the workpiece, and measuring head adjustment means that correspond to each of the pair of measuring heads and adjust the positions of the pair of measuring heads, and the control means utilizes processing data, which is input data for processing the workpiece, to control the measuring head adjustment means, thereby moving the pair of measuring heads to a position where the workpiece can be measured.

[0008] With this configuration, to start measurement with the measuring device, it is sufficient to utilize the data from the initial setup and the machining data, which is essentially data for machining, and there is no need for work or setup such as inputting dedicated data for measurement. Furthermore, there is no need for work or setup such as manually adjusting the position of the stylus in advance for measurement. This also applies when the workpiece is replaced with a new workpiece with different machining dimensions. In this case, by utilizing the machining data for the new workpiece, there is no need for dedicated work or setup for measurement.

[0009] In the machining apparatus of the present invention, when the object to be machined and measured of the workpiece is an eccentric circular portion that is eccentric from the center of rotation of the workpiece and has a circular cross-sectional shape, or when the cross-sectional shape of the object to be machined and measured of the workpiece is non-circular, it is preferable that the input data for machining the workpiece to be utilized includes the phase angle of the object to be machined and measured when the workpiece is mounted on the machining apparatus. With this configuration, even when the object to be measured is an eccentric circular portion or a non-circular portion, dedicated work or setup for measurement is not required, and similarly, dedicated work or setup for measurement is not required when the workpiece is replaced with a workpiece having different machining dimensions.

[0010] When there are a plurality of machining and measurement targets on the workpiece in the axial direction of the workpiece, it is preferable to move the workpiece or the machining means in the axial direction of the workpiece to change the machining target surface and the measurement target surface. With this configuration, even when there are a plurality of machining target portions in the axial direction of the workpiece, it is possible to measure these machining target portions with the measuring device. [Effects of the Invention]

[0011] The effects of the present invention are as described above. To start measurement using a measuring device, it is sufficient to utilize the data from the initial setup and the machining data, which is essentially data for machining, eliminating the need for work and setup such as inputting dedicated data for measurement. Furthermore, work and setup such as manually adjusting the position of the stylus in advance for measurement is also unnecessary. This also applies when the workpiece is replaced with a new workpiece with different machining dimensions. In this case, by utilizing the machining data for the new workpiece, dedicated work and setup for measurement are unnecessary. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view showing a main part of a grinding machine according to an embodiment of the present invention; [Figure 2] 2 is a plan view showing the relationship between the grinding wheel and the workpiece in the grinding machine shown in FIG. 1. [Figure 3] FIG. 2 is a side view showing a main part of a grinding machine during grinding of a workpiece in one embodiment of the present invention. [Figure 4] 2 is a side view showing the main part of the grinding machine when the movable arm is rotated from the state in FIG. 1 and the measuring device is moved to a measurement position in one embodiment of the present invention. FIG. [Figure 5] FIG. 2 is an enlarged view of a measurement device according to an embodiment of the present invention. [Figure 6] FIG. 2 is a block diagram showing signal exchange of a grinding machine in one embodiment of the present invention. [Figure 7] 3 is a flowchart showing a series of steps performed by a grinding machine in one embodiment of the present invention. [Figure 8] FIG. 2 is a side view showing a main part of the grinding machine in a state where a workpiece is being measured in an embodiment of the present invention. [Figure 9] FIG. 9 is an enlarged view of the measuring device in the state shown in FIG. 8. [Figure 10] FIG. [Figure 11] FIG. 2 is a cross-sectional view showing a state in which a workpiece having an eccentric circular portion is mounted on a grinding machine in one embodiment of the present invention. [Figure 12] 1 is a side view of a main part showing an example of a method for recognizing a phase angle of a workpiece W when it is attached in an embodiment of the present invention. FIG. [Figure 13] FIG. 10 is a cross-sectional view of a workpiece having an eccentric circular portion after grinding is completed in one embodiment of the present invention. [Figure 14] FIG. 10 is a cross-sectional view showing a state in which the eccentric circle portion is disposed directly above the central axis of rotation in one embodiment of the present invention. [Figure 15] FIG. 10 is a diagram illustrating a state in which a pair of measuring heads have moved to measurement positions where the eccentric circle portion is sandwiched between them, in an embodiment of the present invention. [Figure 16] FIG. 10 is a diagram showing a state in which a pair of probes abuts against an eccentric circle portion in an embodiment of the present invention. [Figure 17] FIG. 2 is a cross-sectional view showing a state in which a workpiece having a non-circular portion is mounted on a grinding machine in one embodiment of the present invention. [Figure 18] FIG. 10 is a cross-sectional view of a workpiece having a non-circular portion after grinding has been completed in one embodiment of the present invention. [Figure 19] FIG. 10 is a cross-sectional view showing a state in which the major axis direction of the non-circular portion is arranged vertically in one embodiment of the present invention. [Figure 20] FIG. 10 is a diagram showing a state in which a pair of measuring heads have moved to measurement positions where the non-circular portion is sandwiched between them in an embodiment of the present invention. [Figure 21] FIG. 10 is a diagram showing a state in which a pair of probes abuts against a non-circular portion in an embodiment of the present invention. [Figure 22] FIG. 2 is a side view of a main part showing a state in which a non-circular hexagonal portion is measured in one embodiment of the present invention. [Figure 23] FIG. 2 is a side view of a main part showing a state in which a non-circular portion of a pentagon is measured in one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below with reference to the drawings. The present invention relates to a processing device equipped with a measuring device for measuring the radial dimension of a workpiece. The type of processing device is not particularly limited, but examples include a grinding machine that uses a grinding wheel as the processing means and a lathe that performs cutting using a cutting blade as the processing means. In the following embodiment, the processing device will be described using an example of a grinding machine.

[0014] FIG. 1 is a side view showing the main parts of a grinding machine 1 according to one embodiment of the present invention. FIG. 2 is a plan view showing the relationship between the grinding wheel 4 (machining means) and the workpiece W in the grinding machine 1 shown in FIG. 1. FIG. 1 is a schematic view, and has been appropriately simplified for ease of illustration (the same applies to FIGS. 3, 4, and 8). For example, in a side view, the workpiece W is hidden by the headstock 6 (see FIG. 2), but in FIG. 1, the headstock 6 is omitted from the illustration and the entire workpiece W is shown. Furthermore, although the grinding wheel 4 is covered by a wheel cover, the wheel cover is not shown and the entire outer shape of the grinding wheel 4 is shown.

[0015] As shown in FIG. 1, a wheelhead 3 is installed on a bed 2, and a wheel 4 is mounted on the wheelhead 3. A table 5 is installed on the bed 2, and a tailstock 7 is mounted on the table 5. As mentioned above, although not shown in FIG. 1, a headstock 6 (see FIG. 2) is also mounted on the table 5. As shown in FIG. 2, a workpiece W is sandwiched between a spindle center 6a provided on the headstock 6 and a tailstock center 7a provided on the tailstock 7. Center holes (recesses) are formed on both ends of the workpiece W, so when the workpiece W is sandwiched between the spindle center 6a and the tailstock center 7a, the workpiece W is accurately positioned.

[0016] In FIG. 1, the wheelhead 3 is movable in the X-axis direction, which is the direction toward the workpiece W and the opposite direction. In FIG. 2, the headstock 6 and tailstock 7 are movable together with the table 5 in the Z-axis direction, which is the axial direction of the spindle center 6a and tailstock center 7a. The Z-axis direction is perpendicular to the X-axis direction. In this configuration, the workpiece W is ground by moving the wheelhead 3 in the X-axis direction, with the grinding surface 4a of the rotating grinding wheel 4 in contact with the workpiece W, and the surface to be ground can be changed by moving the table 5 in the Z-axis direction.

[0017] As shown in Fig. 1, the grinding machine 1 is equipped with a measuring device 10 and a moving means 40. The measuring device 10 is configured so that the positions of a pair of measuring heads 30a, 30b are adjusted by a measuring head adjusting means 20 (see Fig. 5) built into the main body 11 (housing). Details of the measuring device 10 will be described later with reference to Fig. 5.

[0018] In Fig. 1, moving means 40 moves measuring device 10, and has a support 42 fixed to a support 41. A movable arm 43 is attached to support 42 via a rotation shaft 44, and measuring device 10 is fixed to movable arm 43. In the state of Fig. 1, the pair of measuring heads 30a, 30b are in a retracted position retracted from the measurement position where they sandwich workpiece W. From the state of Fig. 1, by rotating movable arm 43 around rotation center 45 of rotation shaft 44 (arrow a), the pair of measuring heads 30a, 30b move to the measurement position where they sandwich workpiece W.

[0019] In this embodiment, an example will be described in which the grinding machine 1 is equipped with the moving means 40, but the moving means 40 may be omitted. For example, the pair of measuring heads 30a, 30b may be spaced far enough apart from the workpiece W during grinding, and the pair of measuring heads 30a, 30b may be moved closer to the workpiece W during measurement.

[0020] 3 is a side view showing the main parts of the grinding machine 1 during grinding of the workpiece W. In the state of FIG. 3, the wheelhead 3 has advanced in the X-axis direction from the state of FIG. 1, and the rotating wheel 4 is in contact with the workpiece W. When grinding is completed, the wheelhead 3 retreats in the X-axis direction and returns to the position shown in FIG. 1.

[0021] Fig. 4 is a side view showing the main parts of the grinding machine 1 when the movable arm 43 is rotated from the state in Fig. 1 and the measuring device 10 is moved to the measurement position. In the state in Fig. 4, the pair of measuring heads 30a, 30b have moved in a direction that reduces the distance between them compared to the state in Fig. 1. Details of the position adjustment of the pair of measuring heads 30a, 30b during this period will be explained later.

[0022] FIG. 5 is an enlarged view of the measuring device 10 in the state shown in FIG. 4, showing the inside of the main body 11 for convenience. The pair of measuring heads 30a, 30b have the same basic configuration, but are denoted by different reference numerals for convenience. The measuring head 30a has a support 32a fixed to a head 31a, and a probe 33a is supported at the tip of the support 32a. Similarly, the measuring head 30b has a support 32b fixed to the head 31b, and a probe 33b is attached to the tip of the support 32b. Both of the pair of measuring heads 30a, 30b are connected to the measuring head adjustment means 20.

[0023] The measuring head adjustment means 20 uses a ball screw mechanism. Specifically, the rotating shaft of a servo motor 21 is connected via a coupling 22 to a ball screw 24 supported by a support bearing 23. The ball screw 24 is engaged with a ball screw nut 25. The ball screw nut 25 is integral with a cylindrical body 26, which is supported on the main body 11 through a hollow support body 27. When the ball screw 24 is driven to rotate by the servo motor 21, the cylindrical body 26 integrated with the ball screw nut 25 moves up and down in accordance with the direction of rotation of the ball screw 24, and the measuring heads 30a, 30b also move up and down integrally with the ball screw nut 25.

[0024] 6 is a block diagram showing signal exchanges in the grinding machine 1. The grinding machine 1 is numerically controlled by an NC (numerical control) device 50. The NC device 50 performs overall control of the grinding machine 1, including the movement of the wheelhead 3 in the X-axis direction by the wheelhead feed motor 13, the rotational drive of the spindle built into the headstock 6 (see FIG. 2) by the spindle servo motor 12, and the rotational drive of the wheel 4 by the wheel drive motor 14, all of which are required to machine the workpiece W. In addition, the NC device 50 also controls the measuring device 10 and the moving means 40.

[0025] 7 is a flowchart showing a series of steps performed by the grinding machine 1. Below, the grinding machine 1 will be described in order of steps according to this flowchart. Below, as shown in FIGS. 1 to 5, a case will be described in which the object to be machined and measured is a circular part centered on the center of rotation of the workpiece W, followed by a case in which the object to be machined and measured is an eccentric circular part (with a cross-sectional shape that is a circle) that is eccentric from the center of rotation of the workpiece W, and finally a case in which the object to be machined and measured is a non-circular part (with a cross-sectional shape that is not a circle).

[0026] When machining the workpiece W, initial settings are made in advance (step 100 in FIG. 7). The initial settings are for measurement by the measuring device 10 and for machining by the grinding machine 1. In either case, the initial settings are for setting the coordinate of the rotation center axis c (see FIG. 1) of the workpiece W. In the case of initial settings for machining by the grinding machine 1, the cutting direction (horizontal direction) is set. The coordinate of the rotation center axis c is also used as a reference value when measuring the workpiece W by the measuring device 10 (see FIG. 6). Since the coordinate of the rotation center axis c is determined by the structure of the grinding machine 1, a known value may be used, but an actual measured value may also be used in consideration of variations due to ambient temperature. When an actual measured value is used, a master workpiece is attached to the grinding machine 1 and the outer diameter of the master workpiece is measured by the measuring device 10.

[0027] 5, as described above, the pair of measuring heads 30a, 30b move integrally with the rotation of the ball screw 24 which is rotationally driven by the servo motor 21 provided in the measuring head adjustment means 20. Furthermore, as shown in FIG. 6, the measuring head adjustment means 20 is controlled by the control means 80 provided in the NC device 50. Therefore, the control means 80 can recognize position information of the pair of measuring heads 30a, 30b.

[0028] When measuring the master workpiece to calculate the coordinate of the rotation center axis c of the workpiece W, as shown in Fig. 9, which will be described later, a pair of probes 33a, 33b are brought into contact with the master workpiece, and the outer diameter of the master workpiece is measured from the pair of position information of the pair of measuring heads 30a, 30b at this time. Therefore, if the workpiece W is the master workpiece in Fig. 9, the control means 80 can calculate the coordinate of the rotation center axis c of the workpiece W from the measured outer diameter of the master workpiece. The calculated coordinate of the rotation center axis c of the workpiece W is stored as workpiece center coordinates 71 in the storage means 70, as shown in Fig. 6.

[0029] Once the initial settings are complete, data for machining the workpiece W is input (step 101 in FIG. 7). The input data is input by the input means 60 provided in the NC device 50 shown in FIG. 6 and is saved as machining data 72 in the storage means 70. When the workpiece W to be machined is a non-eccentric circular portion, the input data is at least the workpiece finishing position (X-axis coordinate value: distance R from the rotation center axis c). After the data input, the process moves to the creation of a machining program 73 (step 102 in FIG. 7).

[0030] The storage means 70 is provided with a machining program 73 that corresponds to the shape of the workpiece W to be machined, such as a non-eccentric circular portion. The control means 80 reflects the input data stored in the machining data 72 in this machining program 73, and creates a new machining program 73 dedicated to the workpiece W to be machined.

[0031] Once the creation of the machining program 73 is complete, the process proceeds to the grinding process (step 103 in FIG. 7). In the grinding process, as shown in FIG. 3, the rotating grinding wheel 4 is in contact with the workpiece W. During the grinding process, the machining program 73 is executed, and the wheelhead 3 moves forward in the X-axis direction until the grinding surface 4a of the grinding wheel 4 reaches the input workpiece finishing position.

[0032] When grinding is completed as a result of the end of execution of the machining program 73, the wheelhead 3 retreats in the X-axis direction and returns to the position shown in Fig. 1. From this state, by rotating the movable arm 43 from the center of rotation 45 of the rotation shaft 44 (arrow a), the measuring device 10 moves to the measurement position where the pair of measuring heads 30a, 30b sandwich the workpiece W, as shown in Fig. 4 (step 104 in Fig. 7). From this state, the process proceeds to the measurement of the workpiece W (step 105 in Fig. 7).

[0033] 4, the pair of measuring heads 30a, 30b are adjusted in advance so that they sandwich the workpiece W and are spaced a distance α (see FIG. 5) from the workpiece W. As a result, even when the measuring device 10 moves to the measurement position, the pair of measuring heads 30a, 30b do not interfere with the workpiece W, and measurement can be performed as is by bringing the pair of measuring heads 30a, 30b closer to the workpiece W.

[0034] As mentioned above, FIG. 5 is an enlarged view of the measuring device 10 in the state shown in FIG. 4. As shown in FIG. 5, the positions of the measuring heads 30a and 30b before measurement is started are adjusted by the measuring head adjustment means 20 so that the tip positions of the probes 33a and 33b are spaced apart by a total distance (R + α) obtained by adding the dimension α to the distance R from the central axis of rotation c of the workpiece W. As mentioned above, the coordinates of the central axis of rotation c of the workpiece W are stored in the storage means 70 as workpiece center coordinates 71 (see FIG. 6), and the distance R from the central axis of rotation c of the workpiece W is stored in the storage means 70 as processing data 72 (see FIG. 6). The dimension α is a fixed value, and a value of about several mm may be stored in advance in the storage means 70 (see FIG. 6).

[0035] That is, to start measurement using the measuring device 10, it is sufficient to utilize the data from the initial setup and the processing data 72, which is essentially data for grinding, and there is no need for work or setup such as inputting dedicated data for measurement. Furthermore, there is also no need for work or setup such as manually adjusting the positions of the measuring heads 30a and 30b in advance for measurement. This also applies when the workpiece W is replaced with a workpiece having different processing dimensions. In this case, when the workpiece W is replaced, the finishing position of the new workpiece W' (X-axis coordinate value: distance R' from the rotation center axis c) is saved as the processing data 72 (see FIG. 6). Furthermore, the data from the initial setup and the dimension α can be continued to be used. Therefore, even when the workpiece W is replaced with a workpiece having different processing dimensions, there is no need for dedicated work or setup for measurement.

[0036] In the measurement process of the workpiece W (step 105 in FIG. 7), the pair of heads 31a, 31b are moved from the state in FIG. 5 to a target position by the measuring head adjustment means 20. The target position is not particularly limited, but is the position where the tips of the pair of probes 33a, 33b press against the workpiece W, assuming that the outer diameter of the workpiece W is the reference dimension 2R. Such control is possible because, as described above, in FIG. 6, the distance R is stored as processing data 72 and the coordinates of the rotation center axis c are stored as workpiece center coordinates 71.

[0037] The pair of supports 32a, 32b are slightly inclined toward the workpiece W with respect to the pair of heads 31a, 31b. Even after the tips of the pair of probes 33a, 33b come into contact with the workpiece W, as the pair of heads 31a, 31b move toward the workpiece W, the tips of the pair of probes 33a, 33b press against the workpiece W, and the degree of inclination of the pair of supports 32a, 32b also changes. A signal is output from the pair of heads 31a, 31b in accordance with the degree of inclination, and the relationship between the degree of inclination and the output signal is known. Therefore, it is possible to detect the deviation of the outer diameter of the workpiece W from the reference dimension 2R from the value of the output signal when the pair of heads 31a, 31b are moved to the target position.

[0038] The above describes the measurement of the workpiece W using the measuring device 10, but the measuring heads 30a and 30b may be any type that can detect deviation from the reference dimension 2R, and may be optical rather than contact type as described above.

[0039] Next, we will explain the case where the object to be machined and the object to be measured are eccentric circular portions (with a cross-sectional shape that is a perfect circle) that are eccentric from the center of rotation of the workpiece W. Fig. 10 shows a perspective view of the workpiece W having an eccentric circular portion 90. The workpiece W is a crankshaft, and has main shafts 91 on both sides, with the eccentric circular portion 90 (clamp pin) provided between counterweights 92. When the workpiece W is mounted on the grinding machine 1, one or both of the left and right ends of the main shaft 91 are held by a chuck mechanism (not shown).

[0040] Fig. 11 shows a cross-sectional view (cross-section AA in Fig. 10) of the workpiece W mounted on the grinding machine 1. The finishing diameter of the eccentric circle portion 90 is Ra, and the amount of eccentricity between the eccentric circle portion 90 and the main shaft 91 is E. Fig. 11 also shows a state in which the phase angle of the eccentric circle portion 90 is set to the phase angle θ1 at the start of grinding.

[0041] The steps will be explained below in order according to the flowchart shown in Fig. 7. The initial setting (step 100 in Fig. 7) is the same as when the object to be machined and the object to be measured are perfectly circular parts that are not eccentric. The coordinates of the central axis c of rotation of the workpiece W (see Fig. 1) set in the initial setting remain the same even if the workpiece W is replaced with one of a different shape, so if the initial setting has already been completed, the initial setting can be used as is.

[0042] Once the initial settings are complete, data for machining the workpiece W is input (step 101 in FIG. 7). The input data is input by the input means 60 provided in the NC device 50 shown in FIG. 6, and is saved as machining data 72 in the storage means 70. The input data includes at least the finishing diameter Ra of the eccentric circular portion 90, the amount of eccentricity E, and the phase angle θ1 of the eccentric circular portion 90 at the start of grinding, as shown in FIG. 11.

[0043] When the workpiece W is mounted on the grinding machine 1, the eccentric circle portion 90 is fixed at an arbitrary phase angle, so the control unit 80 cannot recognize the phase angle of the eccentric circle portion 90. Therefore, the eccentric circle portion 90 cannot be set to the phase angle θ1. Below, three examples of a method for recognizing the phase angle of the workpiece W when mounted are described. These three examples are merely illustrative, and other methods may be used. FIG. 12 is a side view of the main portion of the first example. In FIG. 12, the end of the main shaft 91 is illustrated in cross section for convenience. One or both ends of the workpiece W are chucked. The main shaft 91 shown in FIG. 12 has a key groove 91a on the outer periphery of the main shaft 91 of the workpiece W shown in FIG. 10. A key 6b provided on the rotating part of the headstock 6 is fitted into the key groove 91a. As a result, the eccentric circle portion 90 is fixed at a known phase angle (already input into the control unit 80). Therefore, the workpiece W can be rotated based on this known phase angle until the phase angle θ1 is reached.

[0044] The second example corresponds to the example in Fig. 12, in which key 6b is replaced with a contact plate fixed to table 5 (see Fig. 1) or the like. The spindle is stopped at a fixed phase angle each time, and when the workpiece W shown in Fig. 10 is mounted, the workpiece W is chucked with the eccentric circular portion 90 in contact with the contact plate. According to this method, the phase angle when the spindle is stopped and the position of the contact plate are known, so the workpiece W can be rotated using this known phase angle as a reference until the phase angle reaches θ1.

[0045] In the third example, when a sizing device is provided that can measure slight eccentricity by tilting the measuring point, the spindle is rotated with the measuring point of the sizing device in contact with the workpiece. Then, the workpiece W is rotated until the phase angle reaches θ1, based on the point at which the movement of the measuring point is greatest, i.e., when the eccentric circular portion 90 is directly above (phase angle 0 degrees) or directly below (phase angle 180 degrees) the rotation central axis c.

[0046] 6, the control means 80 provided in the NC device recognizes the current phase angle of the spindle built into the headstock 6 (see FIG. 1). Therefore, even if the workpiece W rotates around the rotation central axis c thereafter, the control means 80 will be able to recognize the phase angle of the eccentric circle portion 90.

[0047] After the data is input, a processing program 73 is created (step 102 in FIG. 7), and the process proceeds to the grinding process (step 103 in FIG. 7). In the grinding process, the rotating grinding wheel 4 (see FIG. 1) moves forward and backward repeatedly in accordance with the movement of the eccentric circular portion 90, which moves while rotating around the central rotation axis c, and comes into contact with the eccentric circular portion 90, thereby performing grinding.

[0048] When grinding is completed as the execution of the machining program 73 ends, the wheelhead 3 retreats in the X-axis direction. FIG. 13 shows a cross-sectional view (cross-section AA in FIG. 10) of the workpiece W mounted on the grinding machine 1 after grinding is completed. In this state, the phase angle of the eccentric circle portion 90 is θ2. As described above, the control means 80 can recognize the phase angle of the eccentric circle portion 90, and therefore also recognizes the phase angle θ2 after grinding is completed. Therefore, the eccentric circle portion 90 can be positioned directly above or below the rotation center axis c in response to a command from the control means 80.

[0049] FIG. 14 shows a state in which the eccentric circle portion 90 is positioned directly above the rotation center axis c. FIG. 15 shows a state in which, with the eccentric circle portion 90 positioned as in FIG. 14, the pair of measuring heads 30a, 30b have moved to measurement positions that sandwich the eccentric circle portion 90. FIG. 16 shows a state in which the pair of probes 33a, 33b abuts against the eccentric circle portion 90. In FIG. 15, the pair of measuring heads 30a, 30b are adjusted in advance so that they sandwich the eccentric circle portion 90 and are spaced a distance α from the eccentric circle portion 90. This adjustment is the same as for a perfectly circular portion that is not eccentric, and is possible because the finishing diameter Ra and the amount of eccentricity E of the eccentric circle portion 90 are stored as processing data 72 in the memory means 70 shown in FIG. 6, as described above.

[0050] As a result, even when the measuring device 10 moves to the measurement position, the pair of measuring heads 30a, 30b will not interfere with the eccentric circular portion 90, and measurement can be carried out as is by bringing the pair of measuring heads 30a, 30b closer to the eccentric circular portion 90. The subsequent steps are the same as in the case of a non-eccentric circular portion, and the measured value of the outer diameter of the eccentric circular portion 90 can be obtained from the detected displacement (difference from the reference dimension Ra) and the reference dimension Ra, and the amount of eccentricity E can also be detected.

[0051] According to the above, even when the measurement target is an eccentric circular portion 90, no dedicated work or setup is required for measurement, just as in the case of a non-eccentric circular portion. This also applies when the workpiece W is replaced with a workpiece having different machining dimensions.

[0052] Furthermore, although the machining and measurement of the eccentric circular portion 90 of the workpiece W shown in FIG. 10 has been described, the main shaft 91 of the workpiece W is also subject to machining and measurement. As described with reference to FIG. 2, the surface to be ground can be changed by moving the table 5 in the Z-axis direction and moving the headstock 6 and tailstock 7 in the Z-axis direction. This makes it possible to machine and measure the main shaft 91 as well. Alternatively, the surface to be ground may be changed by moving the wheelhead 3 (see FIG. 1) in the Z-axis direction. In this configuration, the measuring device 10 may also be moved in the Z-axis direction together with the movement of the wheelhead 3 in the Z-axis direction.

[0053] The machining and measurement in these cases are the same as in the case of the non-eccentric circular portion described above. The position in the Z-axis direction and the finishing diameter of the main shaft 91 are saved as machining data 72, so no dedicated work or setup is required for measurement, as in the case of the eccentric circular portion 90. Furthermore, the workpiece W shown in FIG. 10 is not limited to the example of a crankshaft, and if there are multiple portions to be machined in the axial direction of the workpiece, machining and measurement similar to the example of the crankshaft are possible.

[0054] Next, we will explain what happens when the cross-sectional shapes of the workpiece and the measurement object are non-circular. Figure 17 shows a cross-sectional view of a workpiece W mounted on a grinding machine 1. The workpiece W is composed of a non-circular portion 95, and its cross-sectional shape is elliptical. One or both of the left and right axial ends of the non-circular portion 95 are held by a chuck mechanism (not shown). The finishing dimension of the non-circular portion 95 in the major axis direction is Rb, and in the mounted state of Figure 17, the phase angle of the non-circular portion 95 is θ1.

[0055] The steps will be explained below in order according to the flowchart shown in Figure 7. The steps are basically the same as in the case of the eccentric circular portion 90, but the overlapping parts will also be explained again. The initial setting (step 100 in Figure 7) is the same as when the object to be machined and the object to be measured are circular portions. The coordinates of the rotation center axis c (see Figure 1) of the workpiece W set in the initial setting remain the same even if the workpiece W is replaced with one of a different shape, so if the initial setting has already been completed, the initial setting can be used as is.

[0056] Once the initial settings are complete, data for machining the workpiece W is input (step 101 in FIG. 7). The input data is input by the input means 60 provided in the NC device 50 shown in FIG. 6 and is saved as machining data 72 in the storage means 70. The input data includes at least the finishing dimension Rb in the major axis direction of the non-circular portion 95, the dimension in the minor axis direction, and the phase angle θ1 of the non-circular portion 95 shown in FIG. 17. The method for recognizing the phase angle of the workpiece W when it is mounted is the same as in the case of the eccentric circular portion described above.

[0057] As described above, in Fig. 6, the control means 80 provided in the NC device recognizes the current phase angle of the spindle built into the headstock 6 (see Fig. 1). Therefore, even if the workpiece W rotates around the central axis of rotation c thereafter, the control means 80 will be able to recognize the phase angle of the non-circular portion 95.

[0058] After the data is input, a processing program 73 is created (step 102 in FIG. 7), and the process proceeds to the grinding process (step 103 in FIG. 7). In the grinding process, the rotating grinding wheel 4 (see FIG. 1) repeatedly moves forward and backward in accordance with the movement of the non-circular portion 95, which moves while rotating around the rotation center axis c, and comes into contact with the non-circular portion 95, thereby performing grinding.

[0059] When grinding is completed as the execution of the machining program 73 ends, the wheelhead 3 retreats in the X-axis direction. FIG. 18 shows a cross-sectional view of the non-circular portion 95 attached to the grinding machine 1 after grinding is completed. In this state, the phase angle of the non-circular portion 95 is θ2. As described above, the control means 80 can recognize the phase angle of the non-circular portion 95, and therefore also recognizes the phase angle θ2 after grinding is completed. Therefore, it is possible to position the non-circular portion 95 so that either the major axis direction or the minor axis direction is vertical, based on a command from the control means 80.

[0060] FIG. 19 shows a state in which the non-circular portion 95 is positioned with its major axis direction oriented vertically. FIG. 20 shows a state in which, with the non-circular portion 95 positioned as shown in FIG. 19, the pair of measuring heads 30a, 30b have moved to measurement positions that sandwich the non-circular portion 95. FIG. 21 shows a state in which the pair of probes 33a, 33b abut against the non-circular portion 95. In FIG. 20, the pair of measuring heads 30a, 30b are adjusted in advance so that they sandwich the non-circular portion 95 and are spaced a distance α from the non-circular portion 95. This adjustment is the same as for a non-eccentric circular portion, and is possible because the finishing dimension Rb of the non-circular portion 95 in the major axis direction is stored as processing data 72 in the storage means 70 shown in FIG. 6, as described above.

[0061] As a result, even when the measuring device 10 moves to the measurement position, the pair of measuring heads 30a, 30b do not interfere with the non-circular portion 95, and measurement can be carried out by bringing the pair of measuring heads 30a, 30b closer to the non-circular portion 95. The subsequent steps are the same as in the case of a non-eccentric circular portion, and the measured value of the dimension in the major axis direction of the non-circular portion 95 can be obtained from the detected displacement (difference from the reference dimension Rb) and the reference dimension Rb. If the non-circular portion 95 is arranged with its minor axis direction perpendicular, it becomes possible to measure the dimension in the minor axis direction of the non-circular portion 95.

[0062] As described above, even when the measurement target is a non-circular portion 95, no dedicated work or setup is required for measurement, just as in the case of a circular portion. This also applies when the workpiece W is replaced with a workpiece having different machining dimensions. Furthermore, not only when the non-circular portion 95 is elliptical, but also when it is polygonal, it becomes possible to measure dimensions such as the distance between the planes of the polygon.

[0063] Fig. 22 is a side view of the essential parts showing the state of measurement of a hexagonal non-circular portion 96. In this figure, a pair of probes 33a, 33b abut on the upper and lower flat surfaces of the non-circular portion 96. Fig. 23 is a side view of the essential parts showing the state of measurement of a pentagonal non-circular portion 97. In this figure, a pair of probes 33a', 33b' abut on the upper vertex and the lower flat surface of the non-circular portion 96. Since the probes 33a', 33b' abut on the vertices of the workpiece, they have a different shape from the probes 33a, 33b of the above embodiment.

[0064] Although the embodiment of the present invention has been described above, the embodiment is merely an example and may be modified as appropriate. For example, the control means 80 shown in Fig. 6 is included in the NC device 50, but a control means dedicated to controlling the measuring device 10 may be provided separately from the NC device. [Explanation of symbols]

[0065] 1 grinding machine 4 Grinding wheels 10. Measuring equipment 20 Measuring head adjustment means 30a, 30b, 30a', 30b' Measuring head 40 Transportation 50 NC device 72 Processing data 80 Control Means 90 Eccentric circle part 95,96,97 Non-circular part double work

Claims

1. A numerically controlled machining device that processes a workpiece with a machining means, a storage means; a control means; a measuring device for measuring a radial dimension of the workpiece, The measuring device is a pair of measuring heads that sandwich the workpiece; a measuring head adjusting means corresponding to each of the pair of measuring heads and adjusting the positions of the pair of measuring heads, The control means utilizes processing data, which is input data for processing the workpiece, to control the measuring head adjustment means, thereby moving the pair of measuring heads to a position where the workpiece can be measured.

2. 2. The processing device according to claim 1, wherein when the workpiece to be processed and measured is an eccentric circular portion that is eccentric from the center of rotation of the workpiece and has a cross-sectional shape that is a perfect circle, or when the cross-sectional shape of the workpiece to be processed and measured is a non-circular portion, the input data for processing the workpiece to be utilized includes a phase angle of the workpiece to be processed and measured when the workpiece is mounted on the processing device.

3. 3. The processing device according to claim 1, wherein when there are multiple objects to be processed and measured on the workpiece in the axial direction of the workpiece, the workpiece or the processing means is moved in the axial direction of the workpiece to change the surfaces to be processed and the surfaces to be measured.

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