Measuring device and measuring method

Abstract

To accurately and efficiently measure an outer diameter or an inner diameter of a workpiece.SOLUTION: A measuring apparatus 1 includes an inner diameter measuring part 10 for measuring an inner diameter d of an annular workpiece W, a thickness measuring part 30 for measuring thickness t in a radial direction R of the workpiece W, and an outer diameter calculation part 40 for calculating an outer diameter D of the workpiece W, on the basis of the measured value of the inner diameter d of the workpiece W measured by the inner diameter measuring part 10 and the measured value of the thickness t of the workpiece W measured by the thickness measuring part 30. The inner diameter measuring part 10 is composed of a first gauge 51 and a second gauge 52 which are arranged on opposite sides relative to a central axis Wa of the workpiece W and face the inner diameter d of the workpiece W. The thickness measuring part 30 is composed of the first gauge 51, and a third gauge 53 which faces the first gauge 51 through the thickness t of the workpiece W in the radial direction R of the workpiece W and faces the outer diameter D of the workpiece W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a measurement device and a measurement method. [Background technology]

[0002] Various techniques are known for measuring the outer or inner diameter of an annular workpiece. For example, Patent Document 1 discloses an in-process sizing control method for machining the inner or outer diameter of an annular workpiece (workpiece). In this method, the outer diameter is measured in advance as the diameter of the non-machined surface in a standard state before machining begins, and the wall thickness is measured with an in-process gauge during machining, and the inner diameter as the diameter of the machined surface is calculated based on both measurements.

[0003] The outside diameter of the non-machined surface of the annular workpiece is accurately and precisely measured in advance in a measuring room under standard conditions and stored in an outside diameter dimension memory. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 58-171260 A (particularly pages 3 and 4 and Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the diameter (inner diameter) of the workpiece's machined surface is not measured directly, but is measured based on the diameter dimension of the workpiece's non-machined surface (outer diameter) and the workpiece's wall thickness. This reduces measurement errors caused by distortion of the workpiece during machining, allowing the diameter (inner diameter) of the workpiece's machined surface to be measured with greater accuracy.

[0006] However, in Patent Document 1, the diameter (outer diameter) of the non-machined surface of the workpiece needs to be precisely measured in a measurement room under standard conditions. That is, before measuring the diameter (outer diameter) of the non-machined surface of the workpiece, the workpiece needs to be removed from the machine tool, and after measuring the diameter (outer diameter), the workpiece needs to be reattached to the machine tool.

[0007] Then, once the workpiece is mounted on the machine tool, machining of the workpiece is resumed. During machining of the workpiece, the diameter (inner diameter) of the machined surface of the workpiece is measured based on the diameter (outer diameter) of the non-machined surface of the workpiece and the thickness of the workpiece, while the thickness of the workpiece is measured.

[0008] In Patent Document 1, the workpiece must be attached and detached from the machine tool before and after measuring the diameter (outer diameter) of the non-machined surface of the workpiece, which means that machining the workpiece and measuring its dimensions takes time and effort, making it inefficient.

[0009] The present disclosure has been made in consideration of the above points, and its purpose is to measure the outer diameter or inner diameter of a workpiece accurately and efficiently. [Means for solving the problem]

[0010] The measuring device according to the present disclosure comprises a one diameter measuring unit that measures one of the outer diameter and inner diameter of a ring-shaped workpiece, a thickness measuring unit that measures the radial thickness of the workpiece, and a other diameter calculating unit that calculates the other of the outer diameter and inner diameter of the workpiece based on the measurement value of the one diameter by the one diameter measuring unit and the measurement value of the thickness by the thickness measuring unit, wherein the one diameter measuring unit is composed of a first gauge and a second gauge that are arranged on opposite sides of the center of the workpiece and face the one diameter, and the thickness measuring unit is composed of the first gauge and a third gauge that faces the first gauge in the radial direction across the thickness of the workpiece and faces the other diameter.

[0011] Since the tool is pressed against the workpiece during machining, the workpiece will bend, especially if the workpiece is thin and easily deformed. Therefore, even if an attempt is made to directly measure the outer diameter or inner diameter of the workpiece during machining, it is not possible to accurately measure the outer diameter or inner diameter of the workpiece. On the other hand, even if the tool is pressed against the workpiece, the thickness of the workpiece hardly changes.

[0012] According to this configuration, the other diameter of the workpiece is calculated based on the diameter of one side of the workpiece measured before machining and the thickness of the workpiece measured during machining, thereby making it possible to accurately measure the other diameter of the workpiece during machining.

[0013] Furthermore, the first and second gauges measure one diameter of the workpiece, and the first and third gauges measure the wall thickness of the workpiece. That is, simply by changing the combination of gauges, it is possible to switch between measuring one diameter of the workpiece and measuring the wall thickness of the workpiece. Therefore, one diameter and wall thickness of the workpiece can be measured efficiently within the machining cycle (without unnecessary work such as attaching and detaching the workpiece to the machine tool).

[0014] As described above, the outer diameter or inner diameter of the workpiece can be measured accurately and efficiently.

[0015] In one embodiment, the other diameter measuring unit is further provided for measuring the other diameter, and the other diameter measuring unit is composed of the third gauge and a fourth gauge that faces the second gauge in the radial direction via the wall thickness of the workpiece and faces the other diameter.

[0016] According to this configuration, for example, when the workpiece is thick and difficult to deform, the other diameter of the workpiece can be easily measured by directly measuring the other diameter of the workpiece using the third gauge and the fourth gauge.

[0017] In one embodiment, the one diameter is an inner diameter and the other diameter is an outer diameter, and the first gauge, the second gauge and the third gauge are arranged side by side along a direction intersecting the pressing direction of the tool against the outer diameter of the workpiece.

[0018] When the tool is pressed against the outer diameter of the workpiece, the workpiece stretches in a direction intersecting the pressing direction. That is, the first, second, and third gauges are arranged along the elongation direction of the workpiece. If an attempt were made to directly measure the outer diameter of the workpiece along the elongation direction, the measurement error caused by the elongation of the workpiece would be large. On the other hand, the wall thickness of the workpiece is hardly affected by the elongation of the workpiece.

[0019] According to this configuration, the outer diameter of the workpiece is calculated based on the inner diameter and wall thickness of the workpiece, so even if the first, second, and third gauges are arranged in a line along the elongation direction of the workpiece, the outer diameter of the workpiece can be measured with high accuracy with almost no effect from the elongation of the workpiece. In other words, the degree of freedom in the arrangement of the gauges can be increased.

[0020] The measurement method according to the present disclosure includes a one-diameter measurement step of measuring one of the outer diameter and inner diameter of an annular workpiece before machining the workpiece; a thickness measurement step of measuring the radial thickness of the workpiece during machining the workpiece; and a other-diameter calculation step of calculating the other of the outer diameter and inner diameter of the workpiece based on the measurement value of the one diameter measured in the one-diameter measurement step before machining and the measurement value of the thickness measured in the thickness measurement step during machining. In the one-diameter measurement step, the one diameter is measured by a first gauge and a second gauge that are arranged on opposite sides of the center of the workpiece and face the one diameter, and in the thickness measurement step, the thickness is measured by the first gauge and a third gauge that faces the first gauge in the radial direction via the thickness of the workpiece and faces the other diameter. [Effects of the Invention]

[0021] According to the present disclosure, the outer diameter or inner diameter of a workpiece can be measured accurately and efficiently. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic configuration diagram showing a measurement device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a view corresponding to FIG. 1 according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0024] First Embodiment (Measuring equipment) FIG. 1 is a schematic diagram showing the configuration of a measuring device 1. The measuring device 1 is installed in a grinding machine (not shown) as a machine tool. The measuring device 1 is primarily used to measure the outer diameter D of an annular (ring-shaped) workpiece W. The workpiece W is, for example, annular.

[0025] The workpiece W is held at one axial end by a chuck (not shown) of the grinding machine. The workpiece W held by the chuck rotates around the central axis Wa by driving the main spindle (not shown). The outer diameter D of the workpiece W is supported by two shoes 2 and 3. The grinding machine is a so-called shoe centerless type. The grinding machine is capable of performing multiple machining operations on the workpiece W.

[0026] An outer diameter side grinding wheel 4 serving as a tool is pressed against the outer diameter D of the workpiece W. The outer diameter side grinding wheel 4 is arranged on the outer periphery of the workpiece W. The outer diameter side grinding wheel 4 rotates around a central axis 4a. The rotation direction Wb of the workpiece W and the rotation direction 4b of the outer diameter side grinding wheel 4 are opposite to each other.

[0027] Similarly, an inner diameter grinding wheel 5 as a tool is pressed against the inner diameter d of the workpiece W. The inner diameter grinding wheel 5 is arranged on the inner periphery side of the workpiece W.

[0028] The measuring device 1 includes an inner diameter measuring unit (one diameter measuring unit) 10, an outer diameter measuring unit (other diameter measuring unit) 20, a wall thickness measuring unit 30, and an outer diameter calculating unit (other diameter calculating unit) 40. The measuring device 1 also includes a first gauge 51, a second gauge 52, a third gauge 53, and a fourth gauge 54.

[0029] Each of the gauges 51 to 54 is, for example, a known contact sensor. Each of the gauges 51 to 54 itself measures the amount of displacement from a reference point (zero point). The reference point is set (zero set) by a master work. The contact sensor has, for example, a built-in extendable spindle. Note that each of the gauges 51 to 54 may also be a non-contact sensor such as an eddy current type, optical type, ultrasonic type, or laser type.

[0030] The first gauge 51 and the second gauge 52 are typically used to measure the inner diameter d, which is one of the outer diameter D and inner diameter d of the workpiece W. The first gauge 51 and the second gauge 52 are arranged on opposite sides of each other with respect to the center axis Wa of the workpiece W. The first gauge 51 and the second gauge 52 face the inner diameter (one of the diameters) d of the workpiece W.

[0031] The third gauge 53 and the fourth gauge 54 are normally used to measure the other of the outer diameter D and the inner diameter d of the workpiece W. The third gauge 53 and the fourth gauge 54 are arranged on opposite sides of the central axis Wa of the workpiece W.

[0032] The third gauge 53 faces the first gauge 51 in the radial direction R of the workpiece W, across the thickness t of the workpiece W. The third gauge 53 faces the outer diameter (the other diameter) D of the workpiece W.

[0033] The fourth gauge 54 faces the second gauge 52 in the radial direction R of the workpiece W, across the thickness t of the workpiece W. The fourth gauge 54 faces the outer diameter (the other diameter) D of the workpiece W.

[0034] The first gauge 51 (third gauge 53) and the second gauge 52 (fourth gauge 54) do not necessarily have to be positioned 180° opposite each other with respect to the central axis Wa of the workpiece W, and may be slightly deviated from 180°.

[0035] Combining the first gauge 51 and the second gauge 52 makes it possible to measure the inner diameter d of the workpiece W. Combining the third gauge 53 and the fourth gauge 54 makes it possible to measure the outer diameter D of the workpiece W. Combining the first gauge 51 and the third gauge 53 makes it possible to measure the wall thickness t of the workpiece W in the radial direction R. Combining the second gauge 52 and the fourth gauge 54 makes it possible to measure the wall thickness t of the workpiece W in the radial direction R.

[0036] When the outer diameter side grinding wheel 4 is pressed against the outer diameter D of the workpiece W in the pressing direction A, the workpiece W is sandwiched between the outer diameter side grinding wheel 4 and the two shoes 2, 3 and deformed. The workpiece W then significantly elongates in a direction where the outer diameter side grinding wheel 4 and the two shoes 2, 3 are not present (hereinafter referred to as "elongation direction B"). The elongation direction B is a direction that intersects with the pressing direction A, for example, a direction B that is perpendicular to the pressing direction A.

[0037] The pressing direction A is also the moving direction of the outer diameter side grinding wheel 4 relative to the outer diameter D of the workpiece W. The first gauge 51, the second gauge 52, the third gauge 53, and the fourth gauge 54 may be arranged side by side along the extension direction B.

[0038] The inner diameter measuring unit 10 is composed of a first gauge 51 and a second gauge 52, and measures the inner diameter d of the workpiece W. The outer diameter measuring unit 20 is composed of a third gauge 53 and a fourth gauge 54, and measures the outer diameter D of the workpiece W.

[0039] The wall thickness measuring unit 30 is composed of a first gauge 51 and a third gauge 53, and measures the wall thickness t in the radial direction R of the workpiece W. The wall thickness measuring unit 30 may also be composed of a second gauge 52 and a fourth gauge 54.

[0040] The outer diameter calculation unit 40 is configured with a microcomputer and a program, and is built into the grinding machine. The outer diameter calculation unit 40 is electrically connected to each of the gauges 51 to 54, and receives signals from each of the gauges 51 to 54.

[0041] The outer diameter calculation unit 40 calculates the outer diameter D of the workpiece W (D = d + 2t) based on the measured value of the inner diameter d of the workpiece W measured by the inner diameter measurement unit 10 (first gauge 51 and second gauge 52) and the measured value of the wall thickness t of the workpiece W measured by the wall thickness measurement unit 30 (first gauge 51 and third gauge 53).

[0042] (Measurement method) A description will be given of a measurement method using the measurement device 1. In the measurement method using the measurement device 1, it is possible to calculate the outer diameter D based on the inner diameter d and the wall thickness t, and it is also possible to directly measure the outer diameter D as usual.

[0043] The measurement method includes a preparation step, an inner diameter measurement step as one diameter measurement step, a wall thickness measurement step, an outer diameter calculation step as the other diameter calculation step, and a completion step. The measurement method is particularly applicable when the workpiece W is thin and easily deformed.

[0044] First, in a preparation step, preparations are made to measure the inner diameter d of the workpiece W. Specifically, the inner diameter d and outer diameter D of the workpiece W are turned using a lathe, the workpiece W is heat-treated, the end face of the workpiece W is ground using a grinding machine, the outer diameter D of the workpiece W is roughly ground using a grinding machine, and the inner diameter d of the workpiece W is roughly ground using a grinding machine.

[0045] Next, in the inner diameter measurement process, finish grinding has not yet been performed as a processing step for the workpiece W. In the inner diameter measurement process, the inner diameter d of the workpiece W is measured by the inner diameter measurement unit 10 (the first gauge 51 and the second gauge 52) before the workpiece W is finish ground.

[0046] Next, in the wall thickness measurement process, the outer diameter D of the workpiece W is finish-ground by the outer diameter side grinding wheel 4. In the wall thickness measurement process, the wall thickness t in the radial direction R of the workpiece W is measured by the wall thickness measuring unit 30 (the first gauge 51 and the third gauge 53) while the outer diameter D of the workpiece W is being finish-ground.

[0047] Next, in the outer diameter calculation step, finish grinding of the outer diameter D of the workpiece W is continued using the outer diameter side grinding wheel 4. In the outer diameter calculation step, the outer diameter D of the workpiece W is calculated during finish grinding of the workpiece W (D=d+2t) based on the measured value of the inner diameter d of the workpiece W measured before finish grinding in the inner diameter measurement step and the measured value of the wall thickness t of the workpiece W measured during finish grinding in the wall thickness measurement step.

[0048] Finally, in the completion step, the inner diameter d of the workpiece W is finish-ground (processed) by the inner diameter side grinding wheel 5.

[0049] If the workpiece W is thick and difficult to deform, the outer diameter D of the workpiece W may be measured directly by the outer diameter measuring unit 20 (the third gauge 53 and the fourth gauge 54).

[0050] (Action and effect) During finish grinding of the workpiece W, the outer diameter side grinding wheel 4 is pressed against the outer diameter D of the workpiece W, which causes the workpiece W to bend, especially if the workpiece W is thin and easily deformed (see the two-dot chain line in Figure 1). For this reason, even if an attempt is made to directly measure the outer diameter D of the workpiece W during finish grinding of the workpiece W, it is not possible to accurately measure the outer diameter D of the workpiece W. On the other hand, even if the outer diameter side grinding wheel 4 is pressed against the outer diameter D of the workpiece W, the wall thickness t of the workpiece W hardly changes.

[0051] According to this embodiment, the outer diameter D of the workpiece W is calculated (D=d+2t) based on the inner diameter d of the workpiece W measured before finish grinding of the workpiece W and the wall thickness t of the workpiece W measured during finish grinding of the workpiece W. This makes it possible to measure the outer diameter D of the workpiece W with high accuracy during finish grinding of the workpiece W.

[0052] Furthermore, the first gauge 51 and the second gauge 52 (inner diameter measuring unit 10) measure the inner diameter d of the workpiece W, and the first gauge 51 and the third gauge 53 (wall thickness measuring unit 30) measure the wall thickness t of the workpiece W. In other words, simply by changing the combination of the gauges 51 to 54, it is possible to switch between measuring the inner diameter d of the workpiece W and measuring the wall thickness t of the workpiece W.

[0053] Therefore, the inner diameter d and wall thickness t of the workpiece W can be measured efficiently within the machining cycle (without unnecessary work such as attaching and detaching the workpiece W to and from the grinding machine).

[0054] As described above, the outer diameter D of the workpiece W can be measured accurately and efficiently.

[0055] When the workpiece W is thick and difficult to deform, the outer diameter D of the workpiece W can be easily measured by directly measuring the outer diameter D of the workpiece W using the third gauge 53 and the fourth gauge 54 (outer diameter measuring unit 20).

[0056] When the outer diameter side grinding wheel 4 is pressed against the outer diameter D of the workpiece W, the workpiece W stretches in an extension direction B perpendicular to the pressing direction A. Here, the first gauge 51, the second gauge 52, the third gauge 53, and the fourth gauge 54 are arranged along the extension direction B of the workpiece W.

[0057] If the outer diameter D of the workpiece W were to be measured directly along the elongation direction B using the third gauge 53 and the fourth gauge 54, the measurement error caused by the elongation of the workpiece W would be large. On the other hand, the wall thickness t of the workpiece W is hardly affected by the elongation of the workpiece W.

[0058] In this embodiment, the outer diameter D of the workpiece W is calculated based on the inner diameter d of the workpiece W and the wall thickness t of the workpiece W, so even if the first gauge 51, the second gauge 52, the third gauge 53, and the fourth gauge 54 are arranged in a line along the elongation direction B of the workpiece W, the outer diameter D of the workpiece W can be measured with high accuracy with almost no effect from the elongation of the workpiece W. In other words, the degree of freedom in arranging the gauges 51 to 54 can be increased.

[0059] Second Embodiment As shown in FIG. 2, the measuring device 1 according to the second embodiment is essentially the same as the measuring device 1 according to the first embodiment, except that the combination of gauges 51 to 54 is changed (the arrangement of symbols 51 to 54 differs between FIG. 1 and FIG. 2).

[0060] The measuring device 1 includes an outer diameter measuring unit 10 that measures the outer diameter D of the annular workpiece W, a thickness measuring unit 30 that measures the thickness t of the workpiece W in the radial direction R, and an inner diameter calculation unit 40 that calculates the inner diameter d of the workpiece W based on the measurement value of the outer diameter D of the workpiece W by the outer diameter measuring unit 10 and the measurement value of the thickness t of the workpiece W by the thickness measuring unit 30.

[0061] The outer diameter measuring unit 10 is composed of a first gauge 51 and a second gauge 52 that are arranged on opposite sides of the central axis Wa of the workpiece W and that face the outer diameter D of the workpiece W.

[0062] The thickness measuring section 30 is composed of a first gauge 51 and a third gauge 53 that faces the first gauge 51 in the radial direction R of the workpiece W through the thickness t of the workpiece W and faces the inner diameter d of the workpiece W.

[0063] The measuring device 1 may further include an inner diameter measuring unit 20 that directly measures the inner diameter d of the workpiece W. The inner diameter measuring unit 20 is composed of a third gauge 53 and a fourth gauge 54 that faces the second gauge 52 in the radial direction R of the workpiece W via the wall thickness t of the workpiece W and faces the inner diameter d of the workpiece W.

[0064] A measurement method according to another embodiment includes an outer diameter measurement process for measuring the outer diameter D of an annular workpiece W before finish grinding the workpiece W, a thickness measurement process for measuring the thickness t of the workpiece W in the radial direction R during finish grinding of the workpiece W, and an inner diameter calculation process for calculating the inner diameter d of the workpiece W based on the measured value of the outer diameter D of the workpiece W measured before finish grinding in the outer diameter measurement process and the measured value of the thickness t of the workpiece W measured during finish grinding in the thickness measurement process.

[0065] In the outer diameter measuring step, the outer diameter D of the workpiece W is measured by a first gauge 51 and a second gauge 52 that are arranged on opposite sides of the central axis Wa of the workpiece W and face the outer diameter D of the workpiece W.

[0066] In the thickness measurement process, the thickness t of the workpiece W is measured by a first gauge 51 and a third gauge 53 that faces the first gauge 51 in the radial direction R of the workpiece W through the thickness t of the workpiece W and faces the inner diameter d of the workpiece W.

[0067] <Other embodiments> Although the present disclosure has been described above with reference to preferred embodiments, such description is not limiting and various modifications are possible.

[0068] The extension direction B does not necessarily have to be perpendicular to the pressing direction A, and may intersect obliquely with it. The other diameter calculation unit 40 may not be built into the grinding machine, but may be provided independently of the grinding machine. The measuring device 1 may be installed in a machine tool other than a grinding machine (for example, a lathe).

[0069] The number of gauges does not need to be four, but a minimum of three is sufficient. That is, a combination of two gauges on the inner diameter side and one on the outer diameter side, or a combination of one gauge on the inner diameter side and two gauges on the outer diameter side, may be used. [Industrial Applicability]

[0070] The present disclosure is applicable to a measurement device and a measurement method, and is therefore extremely useful and has high industrial applicability. [Explanation of symbols]

[0071] d inner diameter D Outer diameter t Thickness double work Wa center axis Wb Rotation direction R Radial direction A Pressing direction B Stretch direction 1. Measuring equipment 2 Shoes 3 Shoe 4. External grinding wheel (tool) 4a Center axis (center) 4b Rotation direction 5. Internal grinding wheel (tool) 10 Inner diameter measurement section (outer diameter measurement section, one-side diameter measurement section) 20 Outer diameter measuring section (inner diameter measuring section, other diameter measuring section) 30 Thickness measurement section 40 outer diameter calculation unit (inner diameter calculation unit, other diameter calculation unit) 51 First Gauge 52 Second Gauge 53 Third Gauge 54 4th Gauge

Claims

1. a one-diameter measuring unit that measures one of the outer diameter and the inner diameter of the annular workpiece; a thickness measuring unit for measuring the thickness of the workpiece in the radial direction; a second diameter calculation unit that calculates the other of the outer diameter and the inner diameter of the workpiece based on the measurement value of the first diameter measured by the first diameter measurement unit and the measurement value of the wall thickness measured by the wall thickness measurement unit, the one diameter measuring unit is composed of a first gauge and a second gauge that are arranged on opposite sides of the center of the workpiece and face the one diameter, a measuring device, wherein the wall thickness measuring unit is composed of the first gauge and a third gauge that faces the first gauge in the radial direction across the wall thickness of the workpiece and faces the other diameter, Further, an other diameter measuring unit is provided to measure the other diameter, The other diameter measuring unit is composed of the third gauge and a fourth gauge that faces the second gauge in the radial direction through the wall thickness of the workpiece and faces the other diameter.

2. 2. The measuring device according to claim 1, the one diameter is an inner diameter, the other diameter is an outer diameter, A measuring device in which the first gauge, the second gauge, and the third gauge are arranged side by side along a direction intersecting a pressing direction of a tool against the outer diameter of the workpiece.

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