Method for placing a workpiece on the table of a measuring device, computer program product and measuring device

Abstract

Method for placing a workpiece (3) on a measuring device (1; 1A; 1B; 1C), wherein the workpiece (3) is placed on a table (2) of a measuring device (1; 1A; 1B; 1C), the method comprising: Using a holding device (4) which is able to hold the workpiece (3) above the table (2); Using an adjustment device (49) which is able to raise and lower an upper surface of the table (2); Holding the workpiece (3) above the table (2) with the holding device (4); Lifting the upper surface of the table (2) with the adjusting device (49) to bring the upper surface of the table (2) into contact with a lower surface of the workpiece (3); and Releasing the holding device (4) from the workpiece (3) after the load of the workpiece (3) has been transferred to the table (2).

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The invention relates to a method for placing a workpiece on a measuring device and to a measuring device. The invention further relates to a computer program product. 2. Description of the state of the art

[0002] Various types of measuring devices are used to measure the dimensions or shape of a product. For example, a coordinate measuring device is used to measure different point positions on a product's surface. A surface characteristics measuring device (form measuring device, profile measuring device, or surface roughness measuring device) is used to measure the exact shape, profile, or roughness of the product's surface. A roundness measuring device, for example, is used to measure the roundness of a cylindrical product.

[0003] In these measuring devices, a workpiece (object) is placed on a table (stage) for measurement. Measurements of various sections of the workpiece are then taken while a measuring head is moved relative to the table according to the specific type of measurement. Different formats are used for the relative movement of the table and measuring head. However, in many measuring devices, the table is moved, and a highly precise guide or bearing mechanism is employed in the movement mechanism to ensure the accuracy of the measuring device.

[0004] In a roundness measuring device, for example, a rotating table is used to rotate a workpiece and measure its circumferential surface. To achieve high-precision rotation, the rotating table uses an air bearing (see Japanese Utility Model Publication No. H03-008969). In the air bearing of the rotating table, an air layer between a few micrometers and tenths of micrometers (microns) thick is formed in a gap between a rotor (on a rotating side) and a stator (on a fixed side). The rotor is held suspended relative to the stator by the stability of the air layer, thus achieving contactless rotation. The rotor and the stator each have a pressure-bearing surface facing the pressure-bearing surface of the other, and the air layer is positioned between them.The shape of any pressure-bearing surface strongly influences the rotational accuracy, which is a key characteristic of the roundness measuring device. Therefore, to achieve a high degree of rotational accuracy, geometric precision on the sub-micron scale is required during the finishing of the pressure-bearing surfaces of the rotor and stator in the air bearing.

[0005] In recent years, the size of objects measured in measuring devices has become extremely large. For example, roundness measurements were required for extremely large workpieces, such as wind turbine rotors and water turbines. To place such large workpieces on the table of a measuring device, the workpiece was lifted by a lifting device, such as a crane or hoist. However, when lifting an extremely large workpiece with a crane, precise movement cannot be expected, compared to a situation where a worker carefully places a small workpiece on a table.

[0006] In other words, if the extremely large workpiece is suspended from the crane, it must be lowered slowly after being moved close to a table surface to avoid collisions and prevent damage to both the workpiece and the table. While a skilled worker may be able to execute the precise movement described above, a typical worker may find the process difficult. Furthermore, a conventional crane or hoist may not be able to set a sufficiently slow speed, or the movement may be intermittent. Given these factors, there is a high probability that collisions between the workpiece and the measuring table will occur while the workpiece is being held by a crane or similar equipment.Furthermore, if a workpiece with a large mass is suspended by a crane or the like, a collision with the workpiece is also violent, and the guide mechanism or the bearing mechanism of the measuring device, which are highly accurate but not flexible, may be damaged, or the like.

[0007] For example, if a workpiece is loaded onto the rotating table of the roundness measuring device described above, the workpiece's load is absorbed by the air gap between the rotor and the stator. In this example, the loaded workpiece is extremely large and very heavy, and if it is loaded with an impact, the load-bearing capacity of the air gap in the bearing will be exceeded, and the opposing surfaces of the rotor and stator may come into contact. If such contact occurs, the opposing surfaces of the air bearing may be damaged, thus degrading the rotational accuracy. Furthermore, if significant damage (abrasion) is caused by contact between solids during rotation, rotation itself may become impossible. In light of these problems, various strategies have been proposed.

[0008] A device and method for transporting a workpiece to a coordinate measuring machine is disclosed in Japanese patent publication no. H02-062006. In this document, a transportable platform is installed above a platform of the measuring machine. Furthermore, the transportable platform is moved from below the measuring machine onto a sliding bed on one side of the measuring machine. In this position, the workpiece is held from above by a crane and placed on the transportable platform. Then, the transportable platform, together with the workpiece placed on it, is pulled onto the platform (i.e., below the measuring machine), and the measurement is performed. With this configuration, a collision during the crane's holding of the workpiece from the sliding bed to the side of the measuring machine is absorbed, and any impact on the platform of the measuring machine is prevented.

[0009] The Japanese public disclosure JP 2003-45942A discloses a measuring device that includes a vibration damping table and is configured to prevent a worktable from oscillating or vibrating and damaging a workpiece during workpiece transfer. In this document, the configuration is such that the worktable of the vibration damping table can be pulled down and locked after the workpiece has been transferred. Such locking after the workpiece has been transferred prevents the vibration damping table from vibrating and damaging the workpiece due to an external force, and unlocking the worktable allows the inherent vibration protection function to be used.

[0010] In the configuration described above, disclosed in Japanese patent publication JP H02-62006 B2, even if the workpiece held by the crane collides with the transportable platform during transport, the impact on the platform of the measuring device can be mitigated. However, the transportable platform and a mechanism to pull the transportable platform sideways are required, which inevitably complicates the structure. Furthermore, the configuration disclosed in Japanese patent publication JP H02-62006 B2 is not capable of mitigating collisions between the transported workpiece and the transportable platform. Additionally, the transportable platform and the workpiece can be damaged if a collision occurs between the transportable platform and the workpiece.

[0011] The configuration described above, disclosed in the Japanese publication JP 2003-45942A, prevents the worktable from vibrating due to an external force and damaging the workpiece during transport. However, the configuration disclosed in this document is not capable of mitigating collisions between the transported workpiece and the worktable. Furthermore, if a collision occurs between the worktable and the workpiece, the workpiece, the worktable, and the measuring device can be damaged.

[0012] Furthermore, publication JP H11-160 031 A discloses a measuring device. A measuring table, which rotates towards a holding part of a wafer to be measured, and a measuring head for film thickness measurement, which is positioned above the table, are installed on a measuring part of a film thickness gauge. The measuring stage includes a six-axis table, which holds a wafer in a movable position, a sensor for pre-alignment, and an auxiliary stage for supplying a wafer. The six-axis table consists of a holding plate that holds a wafer and a holding mechanism that holds the wafer movable in the respective directions. A wafer can be positioned while being transported over the detection positions defined by the pre-alignment sensor and the measurement positions defined by the measuring head.

[0013] Publication CN 1 02 806 819 A discloses an automatic horizontal adjustment device and an adjustment method for a platform. The automatic horizontal adjustment device for the platform comprises a base plate with an air spring attached to each corner.The air springs are connected to the upper ends of lifting mechanisms mounted in the support legs; the lower ends of the lifting mechanisms are connected to transmission devices; a base is arranged under the support legs; a support seat A is mounted in the middle position under the base plate; fixed adjusting gas valves are also mounted under the base plate and are connected to the air springs via gas lines; one end of a pivot rod is provided with a ball head A and secured by a clamping sleeve mounted on the outside of the support seat A; the other end of the pivot rod is provided with a plumb bob; a suspension arm is attached to the rod body of the pivot rod, the end head of which is positioned accordingly under the contact points of the adjusting gas valves; a locking plate is fixedly arranged on the base, and a movable magnetic block in the plumb bob controls the locking via a remote switch.

[0014] Furthermore, publication JP 2003 - 156 322 A discloses a position measuring device comprising a process in which the position of a wafer in the upper part of a reference position used to arrange the wafer is measured, and in which a first deviation amount is determined as the relative deviation amount of the wafer with respect to the reference position, a process in which the position of the wafer is set based on the first deviation amount, a process in which the position-set wafer is arranged in the reference position, and a process in which the position of the wafer arranged in the reference position is measured and in which a second deviation amount is determined as the deviation amount of the wafer with respect to the reference position. SUMMARY OF THE INVENTION

[0015] The present invention provides a method for placing a workpiece on a measuring device and a measuring device that is able to mitigate collisions of the workpiece during transport without complicating the structure of the device.

[0016] A method according to the invention for placing a workpiece on a measuring device is a method for placing a workpiece on a measuring device in which a workpiece is placed on a table of a measuring device. The method comprises: using a holding device (also referred to as a "holder") that is capable of holding the workpiece above the table, and using an adjustment device that is capable of raising and lowering an upper surface of the table; holding the workpiece above the table with the holding device; raising the upper surface of the table with the adjustment device to bring the upper surface of the table into contact with a lower surface of the workpiece; and releasing the holding device from the workpiece after a load of the workpiece has been transferred from the table.

[0017] In the present invention, contact between the workpiece and the table can be established while the workpiece remains in a state held by the holding device by raising the table relative to the workpiece, which is held above the table. Furthermore, once contact has been established, the load is transferred to the table and any load on the holding device is removed; consequently, the workpiece can be placed on the table. In other words, the process of transferring the load of the workpiece from the holding device to the table is performed in a state where the workpiece and the table are already in contact. Therefore, conditions for a collision do not arise.

[0018] Furthermore, in the present invention, a conventional crane or the like can be used as a holding device for the workpiece, an existing mechanism in the measuring device can be used as an adjustment device for raising and lowering the table, or even in a case where an additional configuration is used, a simple configuration of the device can be maintained. In this way, the problems mentioned above can be solved by the present invention.

[0019] Furthermore, various measuring devices that measure a dimension or shape of a product fall within the scope of the measuring device to which the present invention is applied. For example, the invention can be applied to a coordinate measuring device that measures various point positions on a product's surface; a surface characteristics measuring device that measures an exact shape profile or surface roughness of the product (form measuring device, profile measuring device, or surface roughness measuring device); or a roundness measuring device that, for example, measures the roundness of a cylindrical product. Additionally, an XY table that moves in a plane (e.g., a coordinate measuring device) or a rotating table (e.g., a roundness measuring device) can be used as the table.Examples of a table moving in a plane can include a table that moves only along the X-axis or only along the Y-axis. Conversely, the table can also be capable of moving along a Z-axis in addition to the X- and Y-axes.

[0020] In the inventive method for placing the workpiece on the measuring device, a process is involved in which the load of the workpiece is transferred to the table, preferably a process which, after the table has been raised and after the table has been brought into contact with the lower surface of the workpiece, continues to raise the table and transfers the load of the workpiece to the table.

[0021] In the present invention, when the workpiece and the table are in contact, the load of the workpiece can be transferred from the holding device to the table by an operation that slightly lifts the table. Therefore, when the load of the workpiece is supported by the table, it is unnecessary to move the workpiece while it is held above the table. If the workpiece has a large mass, precise operation of the holding device is required to lower the workpiece. However, according to the present invention, the workpiece is not moved, and therefore the need for such precise operation, which requires specialized skill, is reduced.

[0022] Furthermore, in the inventive method for placing a workpiece on the measuring device, an operation in which the load of the workpiece is transferred to the table can also be an operation that stops the table in a state where the table is in contact with the lower surface of the workpiece and slightly lowers the workpiece in this state. Such an operation in which the workpiece is slightly lowered can be achieved by an operation in which the holding device releases its grip on the workpiece. Alternatively, the load can also be transferred from the holding device to the table by both raising the table and lowering the workpiece.

[0023] In the inventive method for placing the workpiece on the measuring device, the workpiece is held above the table by the holding device, with the table assuming a reference position; the upper surface of the table is raised from the reference position by the adjusting device and is brought into contact with the lower surface of the workpiece; after the load of the workpiece has been transferred to the table, the holding device is released; and the upper surface of the table is lowered by the adjusting device and returned to the reference position.

[0024] In the present invention, the table can be raised from the reference position (e.g., the measuring position in which the measurement is performed with the measuring device) and brought into contact with the workpiece. After the load of the workpiece has been transferred, the workpiece and the table can be returned to the reference position. Therefore, the transfer of the workpiece can be carried out in a position higher than the reference position, and interference with surrounding equipment or the like during the transport of the workpiece can be prevented from the outset.

[0025] In the inventive method for placing the workpiece on the measuring device, the upper surface of the table is lowered by the adjusting device to a waiting position which is lower than the reference position; the workpiece is held by the holding device in a position above the table and lower than the reference position; the upper surface of the table is raised from the reference position by the adjusting device and brought into contact with the lower surface of the workpiece; after the load of the workpiece has been transferred to the table, the holding device is released, and the upper surface of the table is raised by the adjusting device and returned to the reference position.

[0026] In the present invention, the table is moved from the reference position (e.g., the measuring position in which the measurement is performed with the measuring device) to the waiting position and transports the workpiece in this state. Therefore, the workpiece can be held in or near the reference position before contact is made. Consequently, the degree of table movement required to make contact with the workpiece and then return to the reference position can be minimized.

[0027] According to another aspect, a computer program product is specified which is capable of performing the steps of one of the preceding procedures when loaded onto a suitable system and executed.

[0028] A measuring device according to the present invention comprises a table on the upper surface of which a workpiece can be placed, the table being mounted on a base; a measuring device configured to measure the workpiece placed on the upper surface; an adjustment device installed in an area between the upper surface of the table and the base, configured to raise and lower the upper surface relative to the base; a holding device capable of holding the workpiece above the table; and a control system configured to control the adjustment device.to regulate that the upper surface of the table is raised relative to the workpiece in a state in which the workpiece is held above the upper surface by the holding device, so that the upper surface of the table is brought into contact with the lower surface of the workpiece, and so that after the load of the workpiece has been transferred from the table, the holding device is released from the workpiece.

[0029] In the measuring device according to the invention, the adjustment device preferably comprises a vibration damping table arranged between the table and the base, wherein the vibration damping table includes a lower surface element arranged on the base, an upper surface element holding the table, and at least one gas spring arranged on the lower surface element and holding the upper surface element; a gas line supplying gas to the at least one gas spring; and a control valve configured to control or regulate the gas supply to the gas line. Preferably, the control is configured to perform operations of the adjustment device by controlling or regulating the gas supply to the gas spring using the control valve.

[0030] By adding the gas line, which supplies gas to the gas spring, and the control valve, which controls the gas supply to the gas line, to an existing vibration damping table, the adjustment device of the measuring device described above can be implemented extremely easily in the present invention.

[0031] In the measuring device according to the present invention, the vibration damping table is preferably a vibration damping table having a tilt adjustment function and comprising a plurality of gas springs installed between the upper and lower surface elements and a control valve connected to each of the gas springs, wherein the control valve adds gas from the gas line when the gas springs are compressed and releases gas from the gas springs when the gas springs are extended. The adjustment device preferably comprises the vibration damping table and a valve opening / closing control configured to forcibly open and close the control valve. Preferably, the control is configured to control the gas supply to the gas springs by forcibly opening and closing the control valve using the valve opening / closing control.

[0032] In the present invention, the existing vibration damping table with tilt adjustment function includes the gas line and the control valve. By forcibly opening and closing the control valve using the valve opening / closing control, the vibration damping table can therefore act as a control valve for the adjustment device, enabling configuration of the adjustment device using these components and allowing control via the control mechanism. The valve opening / closing control can be any mechanism capable of creating conditions similar to displacement or the like, in addition to the control valve, when the upper surface element is tilted. Examples include an electromagnet, a cylinder device, or the like, which externally actuates the control valve.In addition to the existing vibration damping table with the tilt adjustment function, the adjustment device can therefore be implemented in the present invention by the insignificant addition of the valve opening / closing control, and the further configuration of the device can be greatly simplified.

[0033] In the measuring device according to the invention, the adjustment device can be a lifting / lowering mechanism located on the table and configured to hold the upper surface of the table so that it is able to raise and lower itself. Examples of such a lifting / lowering mechanism include a mechanism in which an air cylinder, which holds the lower surface of the table, is arranged on the table, and the table is raised and lowered relative to a main body of the table by extending and retracting the air cylinder.

[0034] In the present invention, the adjustment device is arranged on the table. Therefore, the configuration of the measuring device can be simplified and made smaller. Furthermore, only the table with the workpiece is raised and lowered, and it is not necessary to raise and lower the entire table assembly. Therefore, the drive force required for raising and lowering can be reduced.

[0035] According to the inventive method for placing the workpiece on the measuring device and the inventive measuring device, by raising and lowering the table the table can be brought into contact with the lower surface of the workpiece before it takes over the load of the workpiece, and collisions with the workpiece during transport can be avoided without complicating the structure of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention is further described in the following detailed description with reference to the accompanying drawings as non-limiting examples of exemplary embodiments, wherein identical reference numerals represent identical parts across the different views of the drawings and wherein: Fig. 1 shows an overall configuration of a first embodiment of the present invention; Fig. 2 shows a control system according to the first embodiment, Fig. 3 is a cross-sectional view showing a normal state of a control valve according to the first embodiment; Fig. 4 is a cross-sectional view showing a lowered state of the control valve according to the first embodiment; Fig. 5 is a cross-sectional view showing a raised state of the control valve according to the first embodiment; Fig. 6 is a cross-sectional view showing a pressed-in state of the control valve according to the first embodiment; Fig. Figure 7 shows a conventional vibration damping table on which the first embodiment is based; Fig. Figure 8 shows a cross-sectional view of a control valve of the conventional vibration damping table; Fig. 9 is a cross-sectional view showing a lowered state of the control valve of the conventional vibration damping table; Fig. 10 is a cross-sectional view showing a raised state of the control valve of the conventional vibration damping table; Fig. 11 is a flowchart showing operations in the first embodiment; Fig. Figures 12A to 12C are schematic views, each showing operations in the first embodiment; Fig. 13 shows a control system according to a second embodiment of the present invention; Fig. 14 is a flowchart showing operations in the second embodiment; Fig. Figures 15A to 15D are schematic views, each showing operations in the second embodiment; Fig. 16 shows a configuration of a third embodiment of the present invention; Fig. 17 shows a configuration of a fourth embodiment of the present invention; Fig. 18 is a cross-sectional view showing a support structure of a table according to the fourth embodiment; Fig. 19 is a cross-sectional view showing a lower limit state of the table according to the fourth embodiment; Fig. 20 is a cross-sectional view showing an upper limit state of the table according to the fourth embodiment; and Fig. Figure 21 shows a configuration of a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] The features shown here are exemplary and serve only to illustrate the embodiments of the present invention. They are presented to demonstrate what is considered the most useful and easily understandable description of the principles and conceptual aspects of the invention. In this respect, no attempt is made to show structural details of the invention in more detail than is necessary for a basic understanding of the invention, since the description, viewed together with the drawings, clarifies for the person skilled in the art how the forms of the present invention can be implemented in practice. First embodiment

[0038] In Fig. 1 is a roundness measuring device 1, a measuring device according to the present invention. The roundness measuring device 1 includes a table 2, on the upper surface of which a workpiece 3 (measurement object) is placed. In the present invention, the workpiece 3 has a greater weight than that which can normally be carried by a worker. Therefore, a crane 4 is used to place the workpiece 3 on the table 2, from which the workpiece 3 is suspended. The crane 4 corresponds to a holding device according to the present invention.

[0039] To prevent a collision between the workpiece 3 and the table 2 when a heavy workpiece 3 is transported in this way using the crane 4, a method according to the invention for placing a workpiece on a measuring device is used in this embodiment.

[0040] The roundness measuring device 1 (measuring device) comprises a main body 10, on the upper surface of which a measuring unit 20 and a table unit 30 are installed. The main body 10 is held on a flat base 9 by means of a vibration damping table 40. The main body 10 is a very rigid, box-shaped structure and maintains the relative positions of the measuring unit 20 and the table unit 30, which are installed on the upper surface of the main body 10, with a high degree of accuracy. The roundness measuring device 1 also comprises an air supply device 50, which supplies compressed air to the table unit 30 and the vibration damping table 40, and a control device 60, which controls the operations of various components.

[0041] The air supply device 50 includes a compressed air source 51, such as a battery or compressor, and a filter regulator 52, which filters and adjusts the pressure of the compressed air from the compressed air source 51. The compressed air from the compressed air source 51 flows through the filter regulator 52, after which the compressed air is supplied to the table device 30 via a line 53 and to the vibration damping table 40 via a line 54.

[0042] The control device 60 consists of a personal computer or the like and controls the operations of the measuring device 20, the table device 30, the vibration damping table 40, and the air supply device 50 according to a predefined operating program. A controller 61 is arranged between the control device 60 and the measuring device 20, the table device 30, the vibration damping table 40, and the air supply device 50. Measurement data acquired by the measuring device 20 are processed according to the predefined operating program to generate measurement results.

[0043] The measuring device 20 includes a column 21, which stands upright on the upper surface of the measuring device main body 10, a sliding piece 22, which moves up and down along the column, an arm 23, which is held by the sliding piece 22 and is able to move horizontally forwards and backwards, and a displacement sensor 24, which is held at a front end of the arm 23.

[0044] According to the operating program executed by the control device 60, the measuring device 20 moves the sliding piece 22 and the arm 23 and moves the displacement sensor 24 towards the workpiece 3 placed on the table 2 in order to perform a measurement on a circumferential surface of the workpiece 3. Measurement data from the displacement sensor 24 are transmitted to the control device 60 and undergo a predefined processing procedure to evaluate the roundness.

[0045] As in Fig. As shown in Figure 2, the table assembly 30 comprises a main table body 31, on the upper surface of which the table 2 is arranged, and a biaxial adjustment mechanism 32, which sets a horizontal position of a longitudinal axis of the table 2 relative to the main table body 31. The table 2 is disc-shaped and is held along the upper surface of the main table body 31.

[0046] The table assembly 30 further comprises a hydrostatic air bearing 33, which holds the main table body 31 so that it is freely rotatable about an axis of rotation perpendicular to the main measuring device body 10, and a drive motor 34, which causes the main table body 31 to rotate about the axis of rotation. The hydrostatic air bearing 33 and the drive motor 34 are housed in the main measuring device body 10.

[0047] Compressed air is supplied to the hydrostatic air bearing 33 from the air supply device 50 via the line 53. Using this compressed air, a thin hydrostatic air layer is formed on a sliding surface of the hydrostatic air bearing 33; this allows the main table body 31 to be rotatably held in a contactless state with a high degree of accuracy.

[0048] The drive motor 34 is connected to the control unit 61 via a cable running through the main body of the measuring device 10. The control unit 61 is connected to the control device 60, supplies electrical drive energy to the control device 60, and causes the drive motor 34 to rotate at a predetermined speed.

[0049] As in Fig. As shown in Figure 2, the vibration damping table 40 comprises a lower surface element 41, which is installed on the base 9, an upper surface element 42, which holds the main body of the measuring device 10, and several gas springs 43, which are arranged on the lower surface element 41 and hold the upper surface element 42. The gas springs 43 are arranged between the upper surface element 42 and the lower surface element 41, for example at three points in a horizontal plane, which contains the center of gravity of the main body of the measuring device 10 held by the upper surface element 42.

[0050] Compressed air is supplied to the gas springs 43 from the air supply device 50 through the line 54. The compressed air inflates the gas springs 43 between the lower surface element 41 and the upper surface element 42, allowing them to absorb vibrations from the lower surface element 41 while supporting the load of the upper surface element 42, and preventing the vibrations from being transmitted to the upper surface element 42.

[0051] The vibration damping table 40 according to this embodiment includes a tilt adjustment mechanism 49 (also referred to as the "adjustment device"). As a tilt adjustment mechanism 49, control valves 45, each connected to the gas springs 43, are installed on the lower surface element 41. The control valves 45 supply compressed air from the line 54 to the gas springs 43 when the gas springs 43 are compressed and release compressed air from the gas springs 43 when the gas springs 43 are extended. An actuating unit 46, which forcibly opens and closes the control valve 45, is arranged for each control valve 45 on the upper surface element 42. Fig. 3, Fig. 4 to Fig. Figure 5 shows the control valves 45 and the actuating units 46 in an enlarged view.

[0052] The control valve 45 comprises a housing 451, which is attached to the lower surface element 41, and a sliding element 452, which can move vertically within the housing 451. A flange 454 of the sliding element 452 is biased upwards by a coil spring 453. A tilting element 457 is installed on an upper section of the housing 451, and an upper end 456 of the sliding element 452 is in contact with a lower surface of the tilting element 457. A tilting end 459 of the tilting element 457 (end section on the side opposite the axis of rotation) is constantly biased upwards by the coil spring 458.

[0053] The line 54 leading to the filter regulator 52 of the air supply device 50 and the line 54 leading to the gas spring 43 are connected through the housing 451, and these two lines 54 communicate with each other via an opening 455 in the housing 451. When the sliding element 452 is at its upper lifting limit, the flange 454 seals the opening 455 through which the two lines 54 communicate. In this state, the supply of compressed air from line 54 to the gas spring 43 is blocked.

[0054] Conversely, if the tilting end 459 of the tilting element 457 is pressed downwards by an external force, the sliding element 452 and the flange 454 are lowered, and the opening 455 is thus opened. In this state, compressed air is supplied from the filter regulator 52 of the gas spring 43 via the line 54. Although the control valve 45 normally blocks the line 54, the line 54 can consequently be opened by pressing down the tilting end 459 of the tilting element 457.

[0055] The actuating unit 46 comprises a bushing 461, which is attached to the upper surface element 42, a shaft 462, which is inserted through the bushing 461 so that it is coaxial with the bushing 461, and a cap 463, which is attached to a lower end of the shaft 462. The cap 463 is arranged above the tilting end 459 of the tilting element 457, and when the upper surface element 42 approaches the lower surface element 41, the tilting element 459 is pressed and the supply of compressed air to the gas spring 43 is initiated (see Fig. 4).

[0056] As in Fig. As shown in Figure 2, the gas spring 43, the control valve 45, and the actuating unit 46 are each arranged at several points on the upper surface element 42 and the lower surface element 41, respectively. If the center of gravity of the workpiece 3 placed on the table 2 is unbalanced relative to the center of the table 2, the load on different sections of the upper surface element 42 is also unbalanced. The greater the load, the more the gas springs 43 are compressed, while the lighter the load, the more the gas springs 43 extend. As a result, the upper surface element 42 is inclined relative to the lower surface element 41, and the two elements are no longer parallel to each other.

[0057] If a point on the upper surface element 42 rises or falls in connection with the inclination, compressed air is also supplied to or released from the gas spring 43 via the control valve 45 connected to the gas spring 43 at this point, and the inclination is automatically corrected.

[0058] When the gas spring 43 installed at one point on the upper surface element 42 contracts and the actuating unit 46 moves downwards at the same point, the tilting element 457 of the control valve 45 is pressed by the actuating unit 46 at the same point and the opening 455 is opened, as shown in Fig. 4 shown. In addition, compressed air is supplied from line 54 to the gas spring 43, the gas spring 43 expands, and the part of the upper surface element 42 that had lowered is raised again.

[0059] When the gas spring 43 installed at one point on the upper surface element 42 expands and the actuating unit 46 moves upwards at the same point, the pressure on the tilting element 457 of the control valve 45 is released by the actuating unit 46 at the same point, the opening 450 is opened and compressed air inside the gas spring 43 is released, as shown in Fig. 5 shown. Consequently, the gas spring 43 contracts, and the part of the upper surface element 42 that had been raised lowers again.

[0060] By actuating the multiple gas springs 43 and each control valve 45 in this manner, the inclination of the upper surface element 42 can be automatically corrected, and the upper surface element 42 can be kept constantly parallel to the lower surface element 41. The inclination adjustment mechanism 49 of the vibration damping table 40 is formed by these components.

[0061] In this embodiment, the lifting / lowering device of the present invention is configured with the tilt adjustment mechanism 49 of the vibration damping table 40 described above. As in the Fig. 2, Fig. 3 and Fig. As shown in Figure 6, a further valve opening / closing mechanism 70, a further line 76 and a further control valve 77 are provided on the air supply device 50 and the actuating unit 46 of this embodiment in order to use the tilt adjustment mechanism 49 as a lifting / lowering device.

[0062] In the actuating unit 46, the shaft 462 is received such that it is able to slide freely in one axial direction relative to the bushing 461. The shaft 462 is pre-tensioned in one direction by a coil spring 71 so that it is received in the bushing, and the cap 463 is held in a state close to the upper surface element 42. A lever 72 is connected to a section that connects the shaft 462 and the cap 463.

[0063] An air cylinder 73, operated by compressed air, is arranged at a position on the upper surface element 42 corresponding to the front end of the lever 72. A line 74 is connected to the air cylinder 73, and by supplying compressed air from the line 74, a front end of the air cylinder 73 moves forward to push the lever 72 downward, and the cap 463 can be moved downward. In this way, with the actuating unit 46 of this embodiment, the cap 463 is moved downward by the supply of compressed air from the line 74, and consequently the control valve 45 can be actuated independently of the inclination of the upper surface element 42.

[0064] At the in Fig. In the air supply device 50 shown in Figure 2, line 74, which leads to the air cylinder 73 arranged at each of the actuating units 46, branches off from line 54, which supplies compressed air to the gas springs 43. A control valve 75, which regulates the compressed air flow, is arranged midway along line 74. Furthermore, a separate outlet line 76 and a control valve 77, which opens and closes the outlet line 76, are provided for each gas spring 43. Line 76 has a larger diameter than line 54 and can release gas with higher efficiency than during the compressed air supply.

[0065] The control valves 75 and 77 are each connected to the control device 60 via the control unit 61 and are controlled according to an operating program executed by the control device 60. In this example, the control valve 75 and all actuating valves 45 between the upper surface element 4 and the lower surface element 41 are opened, thereby extending all gas springs 43 uniformly. Consequently, the upper surface element 42 can be raised relative to the lower surface element 41 (see Fig. 6).

[0066] On the other hand, the control valve 77 is opened and all gas springs 43 are emptied via the lines 76, thereby compressing all gas springs 43 evenly. Consequently, the upper surface element 42 can be lowered relative to the lower surface element 41 (see Fig. 3) In this embodiment, the tilt adjustment mechanism 49 can be used as a lifting / lowering device by incorporating the valve opening / closing mechanism 70 in addition to the air supply device 50 and the actuating unit 46.

[0067] In the Fig. 7, Fig. 8, Fig. 9 to Fig. Figure 10 shows a roundness measuring device 1R which includes an existing vibration damping table 40R capable of tilt adjustment. The roundness measuring device 1R has a basic structure similar to that of the roundness measuring device 1 described above according to the present invention (see Figure 10). Fig. 1, Fig. 2, Fig. 3 to Fig. 4) In particular, in the roundness measuring device 1R, the measuring device main body 10, the measuring device 20, the table device 30 and the control device 60 are similar to those of the roundness measuring device 1 described above.

[0068] In contrast, the vibration damping table 40R and the air supply device 50R, which are described in the Fig. 7, Fig. 8, Fig. 9 to Fig. The roundness measuring device 1R shown in Figure 10 is a configuration which differs in part from that of the vibration damping table 40 and the air supply device 50 shown in the Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. The roundness measuring device 1 shown in 6 differs.

[0069] In Fig. 7 The vibration damping table 40R contains the lower surface element 41, the upper surface element 42 and the gas springs 43, similar to the vibration damping table 40 of the embodiment described above (see Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6) as a tilt adjustment mechanism 49. Although the control valves 45 of the tilt adjustment mechanism 49 of the vibration damping table 40R are similar to those of the present embodiment, the actuating unit 46 differs; the shaft 462 is attached to the bushing 461, and the coil spring 71, the lever 72, the air cylinder 73 and the line 74 of the present embodiment are shown in the figure below. Fig. 3, Fig. 4, Fig. 5 to Fig. 6) are not available.

[0070] In Fig. 7 The air supply device 50R includes a compressed air source 51, a filter regulator 52, a line 53 and a line 54 (see Fig. 2) similar to those of the air supply device 50 of the embodiment described above (see Fig. 2) The line 74, which would run to the actuating unit 46 of the vibration damping table 40R, and the control valve 75, which would interrupt the line 74 (see Fig. 2) are not available.

[0071] The roundness measuring device 1R with the vibration damping table 40R and the air supply device 50R exhibits a similar tilt adjustment effect to that described above for the vibration damping table 40 (in the Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 shown) described by the tilt adjustment mechanism 49 of the vibration damping table 40R.

[0072] If a point on the upper surface element 42 sags, the gas spring 43 installed at that point contracts, as shown in Fig. Figure 9 shows that at this point, the actuating unit 46 also lowers at the same location, and therefore the tilting element 457 of the control valve 45 is pressed by the actuating unit 46 and the opening 455 is opened. In addition, compressed air from line 54 is supplied to the gas spring 43, and the gas spring expands, thus raising the lowered position of the upper surface element 42.

[0073] If a point on the upper surface element 42 lifts, the gas spring 43 installed at that point expands, as shown in Fig. Figure 10 shows that at this point, the actuating unit 46 also rises at the same point, and therefore the pressure through the actuating unit 46 is applied to the tilting element 457 of the control valve 45. The opening 450 is opened, and compressed air inside the gas spring 43 is released. Consequently, the gas spring 43 contracts, and the point on the upper surface element 42 that had risen lowers again.

[0074] By actuating the multiple gas springs 43 and each control valve 45 in this way, the inclination of the upper surface element 42 can be automatically corrected, and the upper surface element 42 can be returned to a horizontal state.

[0075] Again according to the Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6. According to this embodiment, the vibration damping table 40 is added to the one in the Fig. 7, Fig. 8, Fig. 9 to Fig. Figure 10 shows an additional valve opening / closing mechanism 70 (coil spring 71, lever 72, air cylinder 73, line 74 and control valve 75), the outlet line 76 and the control valve 77 added to the existing vibration damping table 40R as described above. In other words, by adding simple configurations (the valve opening / closing mechanism 70, the line 76 and the control valve 77) to the existing vibration damping table 40R described above, the vibration damping table 40 of this embodiment can achieve the effect of the lifting / lowering device of the present invention in addition to the tilt adjustment effect achieved by the tilt adjustment mechanism 49.

[0076] The valve opening / closing mechanism 70, the line 76, and the control valve 77, for example, can use ordinary components, and the focus can be placed on minor improvements. Consequently, the existing vibration damping table 40R can easily be converted into the vibration damping table 40 according to this embodiment without complicating the configuration of the device.

[0077] In this embodiment, the lifting / lowering mechanism of the vibration damping table 40 described above is used, and the workpiece 3, which has a considerable weight, is placed on the roundness measuring device 1. When the workpiece 3 is placed on the table 2 according to the inventive method for placing the workpiece on the measuring device, the workpiece 3 is suspended by the crane 4 (holding device), and the table 2 is raised / lowered to prevent a collision between the workpiece 3 and the table 2.

[0078] To accomplish this, in this embodiment the control valves 75 and 77 of the air supply device 50 are controlled by the control unit 60 to open and close, and the actuating valve 45 is forcibly opened and closed by the valve opening / closing mechanism 70; alternatively, the line 76 and the control valve 77 forcibly release air from the gas spring 43. This raises and lowers the table 2 using the lifting / lowering device (actuating unit 46, actuating valve 45, and gas spring 43), which utilizes the tilt adjustment mechanism 49 of the vibration damping table 40. In particular, the Fig. 12 shown process about the in Fig. 11 operations were performed.

[0079] First, the workpiece 3 is moved by the crane 4 (holding device, see Fig. 1) held hanging (step S1 in Fig. 11), and the suspended workpiece 3 is held above the table 2 (step S2 in Fig. 11, see Fig. 12A). At this point, the height of the upper surface of table 2 is defined as a reference position Po, and the height of a lower surface of workpiece 3 is defined as a holding position Ph. A difference between the reference position Po and the holding position Ph, i.e., a gap between the upper surface of table 2 and the lower surface of workpiece 3, is defined as a distance C. The holding position Ph is set so that it is lower than the upper lifting limit of the lifting / lowering device, which uses the tilt adjustment mechanism 49 of the vibration damping table 40. In this state, the load of workpiece 3 is supported by the crane 4.

[0080] Then, table 2 is lifted from the reference position Po by the lifting / lowering device and brought into contact with the lower surface of workpiece 3 (step S3 in Fig. 11, see Fig. 12B). At this point, a distance L, by which the table 2 is raised, is defined as equal to the distance C. During this operation, the amount of displacement of the raising table 2 is monitored and is preferably configured such that, by raising the table 2 at a sufficiently low speed when making contact with the workpiece 3, even if the table is raised at a high speed before approaching the workpiece 3, no collision occurs when contact is made.

[0081] Then, table 2, which is in contact with the lower surface of workpiece 3, is slightly raised, and the load of workpiece 3 is transferred to table 2 (step S4 in Fig. 11, see Fig. 12B). When the load of workpiece 3 is transferred from table 2, the load is removed from crane 4. At this point, crane 4 is moved away, and the hold on workpiece 3 is released (step S5 in Fig. 11, see Fig. 12B). Consequently, workpiece 3 can be lowered from holding position Ph.

[0082] In the state where the hold on workpiece 3 has been released, table 2 is lowered and reset to the reference position Po (step S6 in Fig. 11, see Fig. 12C). In this way, a state can be achieved in which the workpiece 3 is located at the reference position Po on the table 2. Furthermore, no collision occurs between the table 2 and the workpiece 3 during the placement of the workpiece 3.

[0083] The following advantages can be achieved according to this embodiment. By raising the table 2 relative to the workpiece 3, which is held above the table 2, contact between the workpiece 3 and the table 2 can be established in this embodiment, while the workpiece 3 remains in a state in which it is held by the crane 4 (holding device).

[0084] Furthermore, once contact has been established, the load is transferred from table 2 and the load on crane 4 is released; consequently, workpiece 3 can be placed on table 2. In other words, the operation to transfer the load of workpiece 3 from crane 4 (holding device) to table 2 is performed in a state where workpiece 3 and table 2 are already in contact; therefore, the conditions can be configured so that no collision occurs.

[0085] Furthermore, in this embodiment a conventional crane 4 can be used as a holding device which holds the workpiece 3, and the lifting / lowering device which raises and lowers the table 2 can also have a simple configuration in which an additional valve opening / closing mechanism 70, a line 76 and a control valve 77 are added to an existing tilt adjustment mechanism 49 of the vibration damping table 40.

[0086] In a state where the workpiece 3 and the table 2 are in contact, the load of the workpiece 3 can be relieved in this embodiment by an operation that slightly lifts the table 2 (step S4 in Fig. 11) from the crane 4 (holding device) to the table 2. Therefore, when the load of the workpiece 3 is supported by the table 2, there is no need to move the workpiece 3 while it is held above the table 2. In particular, if the workpiece 3 has a large mass, precise operation of the crane 4 is required to lower the workpiece 3; however, according to this embodiment, the workpiece 3 is not moved, and therefore the need for such precise operation, which requires technical skill, can be eliminated.

[0087] As in the Fig. As shown in Figures 11 and 12A to 12C, in this embodiment, the table 2 is raised from the reference position Po (for example, the measuring position in which a measurement is carried out with the measuring device), brought into contact with the workpiece 3, and after the load of the workpiece 3 has been transferred, the workpiece 3 and table 2 are returned to the reference position Po. Therefore, the transfer of the workpiece 3 can be carried out at the holding position Ph, which is higher than the reference position Po, and interference with surrounding equipment or the like during the transport of the workpiece 3 can be prevented from the outset. Second embodiment

[0088] The Fig. Figures 13 to 15D show a second embodiment according to the present invention. This embodiment uses a roundness measuring device 1 similar to that of the first embodiment described above, but performs a different method than the first embodiment described above.

[0089] In Fig. 13 The roundness measuring device 1 according to this embodiment has a configuration similar to that described above. Fig. 2. However, a control valve 78, which can be operated by the control device 60, is installed on a middle section of the line 54. When the control valve 77 is open and compressed air is forcibly released from the gas springs 43, the control valve 78 is closed, and the supply of compressed air from the control valves 45 to the gas springs 43 is temporarily stopped.

[0090] During an operation described below (step S12 in Fig. 14), in which table 2 is from the reference position Po (see dashed line with two points in Fig. 15A) to a waiting position Pr (see solid line in Fig. 15A) lowered, this configuration prevents the opening of the control valves 45 and the flow of compressed air from the gas springs 43 to the line 76. A description of the operations follows (see Fig. 14) and actions (see Fig. 15A to 15D) in this embodiment.

[0091] First, the workpiece 3 is moved by the crane 4 (holding device, see Fig. 1) held hanging above table 2 (higher than the reference position Po of table 2) (step S11 in Fig. 14). Then table 2 is moved from the reference position Po (see the dashed line with two points in Fig. 15A) to the waiting position Pr (see solid line in Fig. 15A) reduced (step S12 in Fig. 14). Steps S11 and S12 can also be performed in reverse order or simultaneously, in parallel.

[0092] Then the suspended workpiece 3 is lowered and held so that the lower surface of the workpiece 3 is in the holding position Ph, which is lower than the reference position Po (step S13 in Fig. 14; see Fig. 15A). In this state, the load of workpiece 3 is supported by crane 4.

[0093] Then, table 2 is lifted from the waiting position Pr by the lifting / lowering device and brought into contact with the lower surface of the workpiece 3, which is held in the holding position Ph (step S14 in Fig. 14, see Fig. 15B). At this point, the distance L by which the table is raised is defined as equal to the distance C, which is the difference between the waiting position Pr and the holding position Ph. During this operation, the amount of displacement of the raising table 2 is monitored and is preferably configured such that, by raising the table 2 at a sufficiently low speed when making contact with the workpiece 3, even if the table 2 is raised at a high speed before approaching the workpiece 3, no collision occurs when contact is made.

[0094] Then, table 2, which is in contact with the lower surface of workpiece 3, is slightly raised, and the load of workpiece 3 is transferred to table 2 (step S15 in Fig. 14, see Fig. 15B). When the load of workpiece 3 has been transferred from table 2, the load is removed from crane 4.

[0095] In the state where the hold on workpiece 3 is released, table 2 is raised further and returned from the holding position Ph to the reference position Po (step S16 in Fig. 14, see Fig. 15D). In this state, crane 4 is moved away and the hold on workpiece 3 is released (step S17 in Fig. 14) Steps S16 and S17 can also be performed in reverse order or simultaneously, in parallel. This ensures that workpiece 3 is positioned at reference position Po on table 2. Furthermore, no collision occurs between table 2 and workpiece 3 during placement.

[0096] This embodiment can achieve advantages similar to those of the first embodiment described above. Furthermore, in this embodiment, the table 2 is moved from the reference position Po (for example, the measuring position in which the measurement is performed with the measuring device) to the waiting position Pr and transports the workpiece 3 in this state. Therefore, the workpiece 3 can be held in the reference position Po or in the nearby holding position Ph before contact is made. Consequently, the amount of movement required to move the table 2 to make contact with the workpiece 3 and then return to the reference position Po can be minimized. Third embodiment

[0097] Fig. Figure 16 shows a third embodiment according to the present invention. Fig. In this embodiment, a roundness measuring device 1A has a basic configuration similar to that of the roundness measuring device 1 according to the first embodiment described above. Consequently, duplicate descriptions of common configurations are omitted below, and only the parts that differ are described.

[0098] In the first embodiment described above, the coil spring 71, the lever 72 and the air cylinder 73 were added to the actuating unit 46 of the tilt adjustment mechanism 49 of the vibration damping table 40 as a valve opening / closing mechanism 70 (see Fig. 3, Fig. 4, Fig. 5 to Fig. 6), and the line 74 with the control valve 75 arranged on its middle section was connected to the air cylinder 73 (see Fig. 2) In this embodiment, no components are added to the actuating unit 46 of the tilt adjustment mechanism 49 of the vibration damping table 40. Instead, the line 74, which branches off from the air supply device 50 (on the central section of which the control valve 75 is arranged), is connected to the gas spring 43 of the vibration damping table 40.

[0099] Furthermore, the outlet line 76 and the control valve 77, which opens and closes the outlet line 76, are arranged on each gas spring 43, similar to the first embodiment. The line 76 has a larger diameter than the line 54 and can release gas with higher efficiency than during the compressed air supply.

[0100] In this embodiment, the control valves 75 and 77 are opened and closed by the control device 60, and compressed air is supplied to the gas springs 43 from the line 74; this allows the upper surface element 42 of the vibration damping table 40 and the table 2 to be raised, or the table 2 to be lowered by releasing gas from the gas springs 43 using the line 76.

[0101] In this embodiment, the table 2 can be raised and lowered in a similar manner to the first embodiment described above. Furthermore, when the workpiece 3 is placed on the table 2, a collision between the workpiece 3 and the table 2 can be avoided by performing similar operations to those described in the Fig. 11 and 12A to 12C (first embodiment) or the Fig. The process shown in Figures 14 and 15A to 15D (second embodiment) can be applied. Furthermore, the device added to the vibration damping table 40 for raising and lowering the table 2 can simply consist of the lines 74 and 76 to the gas springs 43 and the control valves 75 and 77, and therefore the configuration of the device can be greatly simplified. Fourth embodiment

[0102] The Fig. 17, Fig. 18, Fig. 19 to Fig. Figure 20 shows a fourth embodiment of the present invention. Fig. In this embodiment, a roundness measuring device 1B has a basic configuration similar to that of the roundness measuring device 1 according to the first embodiment described above. Consequently, duplicate descriptions of common configurations are omitted below, and only the parts that differ are described.

[0103] In the first embodiment described above, the lifting / lowering device was configured to raise and lower the table 2 using the tilt adjustment mechanism 49 of the vibration damping table 40. In this embodiment, an additional lifting / lowering mechanism 80 is arranged between the table 2 and the table assembly 30, which enables the raising and lowering of the table 2 relative to the table assembly 30 and thus forms the lifting / lowering device. Specific configurations according to the present embodiment are as follows.

[0104] In Fig. In this embodiment, the table 2 is formed by a disc-shaped table element 81 and can be separated from the table assembly 30. Several air cylinders 83, which are capable of moving upwards using compressed air, are installed on the upper surface of the table assembly 30 (in this embodiment at three locations approximately 120° apart). The table 2 (the table element 81) is held by the air cylinders 83 and can be raised and lowered by supplying or blocking compressed air.

[0105] As in Fig. As shown in Figure 18, several triangular grooves 811, connected in the diameter direction, are formed on the lower surface of the table element 81 (in this embodiment, three are formed at intervals of approximately 120°). The air cylinder 83 contains a ball 831 at one upper end. By contacting the triangular groove 811 using the ball 831, the table 2 (the table element 81) and the table device 30 can be automatically aligned.

[0106] In the Fig. 19 and Fig. The air cylinder 83 contains a housing 832, which is attached to the main table body 31, and a sliding element 833, which is capable of moving vertically within the housing 832. A piston 834 is formed on the sliding element 833, and the piston 834 is biased downwards by a helical spring 835. A line 84 is connected to the housing 832 at a point lower than the piston 834.

[0107] In the air cylinder 83, the piston 834 and the ball 831 are raised by supplying compressed air from the line 84, and the table 2 is raised. Conversely, the piston 834 and the ball 831 are lowered by releasing compressed air inside, and the table 2 is lowered. Furthermore, the upper lifting limit of the table 2 when using the air cylinders 83 is defined as the distance L (see Fig. 16).

[0108] As in Fig. As shown in Figure 17, the line 84, connected to the air cylinder 83, is routed through a central section of the table main body 31 to the outside under the drive motor 34, runs via a freely rotating coupler or the like (not shown in the drawings) through an interior of the measuring device main body 10, and is connected to the air supply device 50. A control valve 85 is installed on a central section of the line 84, and the control valve 85 is connected to the control device 60 via the control 61 (similar to the control valve of the first embodiment described above).

[0109] Consequently, in this embodiment, the control valve 85 opens and closes according to an operating command from the control device 60, and because compressed air is intermittently supplied from the line 84, the table 2 can be raised and lowered using the air cylinders 83. In this embodiment, the raising / lowering mechanism 80 is formed by the table element 81, the air cylinder 83, the line 84, and the control valve 85, and the raising / lowering device is configured by adding the raising / lowering mechanism 80.

[0110] Furthermore, a proximity sensor 82 can be installed at the center of the upper surface of the table element 81 and configured to monitor the approach of the workpiece 3 to the control device 60. With such a configuration, the proximity and contact between the workpiece 3 and the table 2 can be reliably determined, enabling more precise movement. This configuration can also be used to initiate a rapid stop or similar action to prevent a collision.

[0111] In this embodiment, the table 2 can be raised and lowered in a similar manner to the first embodiment described above. Furthermore, when placing the workpiece 3 on the table 2, a collision between the table 2 and the workpiece 3 can be prevented by operations similar to those described in the Fig. 11 and 12A to 12C (first embodiment) or the Fig. The method shown in Figures 14 and 15A to 15D (second embodiment) is used.

[0112] Furthermore, a device added for raising and lowering the table 2 can simply be the raising / lowering mechanism 80 (the table element 81, the air cylinders 83, the line 84, and the control valve 85), which raises and lowers relative to the table assembly 30, thus simplifying the configuration of the device. Specifically, the table element 81 and the air cylinders 83 are installed as the raising / lowering device within the table assembly 30; therefore, the configuration of the measuring device can be simplified and made smaller.

[0113] Furthermore, only table 2 (table element 81) is raised and lowered; therefore, the lifting / lowering section can be kept to a minimum. In other words, only the table is raised and lowered with the workpiece 3, and the entire measuring device main body 10 and the table assembly 30 do not need to be raised and lowered. Therefore, the drive force required for raising and lowering can be reduced. Fifth embodiment

[0114] Fig. Figure 21 shows a fifth embodiment according to the present invention. Each of the embodiments described above includes the tilt adjustment mechanism 49 of the vibration damping table 40, and in each, the control valve 45 is installed on each gas spring 43. However, the present invention can also be configured such that the lifting / lowering device is designed using a vibration damping table 40 that does not include the tilt adjustment mechanism 49.

[0115] In Fig. 21 has a roundness measuring device 1C according to this embodiment, with a basic configuration similar to that of the roundness measuring device 1 according to the first embodiment described above. However, the line 54 from the air supply device 50 is directly connected to the gas springs 43 of the vibration damping table 40, and the control valve 75 is installed on a central section of the line 54.

[0116] By supplying compressed air to the gas springs 43 or by releasing the compressed air through disconnection of the control valve 75 from the control device 60, the extension and contraction of all gas springs 43 can be collectively controlled in this embodiment. Furthermore, by collectively extending and contracting all gas springs 43, the gas springs 43 can function as a lifting / lowering device. Modifications

[0117] Furthermore, the present invention is not limited to the embodiments described above and includes modifications within a framework capable of realizing the advantages of this invention. For example, the table device 30 is not limited to being suspended by the hydrostatic air bearings 33, but can instead be held, for example, by a static hydraulic bearing or by a bearing in which a ball or the like rotates upon contact.

[0118] The vibration damping table 40 is not limited to the use of the gas springs 43. For example, mechanical damping can be used, or a lifting / lowering device can be designed by adding a lifting / lowering mechanism to such a mechanical vibration damping table. However, by inserting the table assembly 30, which uses the hydrostatic air bearings 33, and the vibration damping table 40, which uses the gas springs 43, the air supply device 50 can be used jointly for this purpose.

[0119] Furthermore, in each embodiment, the lifting / lowering device was configured to perform the lifting and lowering operation using compressed air; therefore, the air supply device 50 can also be used to drive the lifting / lowering device. However, the use of the air supply device 50 as a drive source for each of these components is not mandatory in the present invention, and other drive methods can be used instead, such as hydraulic drive, electromagnetic drive, motor drive, or the like.

[0120] The embodiments described above represent examples where the invention was applied to a roundness measuring device. However, various measuring devices that measure a dimension or shape of a product can be used as the measuring device of this invention. For example, the invention can be applied to a coordinate measuring device that measures various point positions on a product's surface, a surface characteristics measuring device that measures an exact shape, profile, or roughness of the product's surface (form measuring device, profile measuring device, or surface roughness measuring device), or a roundness measuring device that, for example, measures the roundness of a cylindrical product.

[0121] Furthermore, the table on which the workpiece is placed is not limited to a rotating table, as in each of the embodiments described above. An XY table (such as a coordinate measuring machine) that moves in a plane can be used instead. Examples of a table that moves in a plane can also include a table that moves only in the X-axis direction or only in the Y-axis direction. Alternatively, the table can also be capable of moving in the Z-axis direction in addition to the X- and Y-axes.

[0122] The present invention can be applied to a method for placing a workpiece on a measuring device and to a measuring device, and it can be particularly advantageously applied when a workpiece with a considerable weight is to be measured.

[0123] It should be noted that the foregoing examples serve purely for illustrative purposes and are in no way to be considered as limiting the invention. While the present invention has been described with reference to exemplary embodiments, it is understood that the words used here are descriptive and illustrative, and not limitative. Amendments may be made within the scope of the attached claims, as defined and as amended, without derogating from the scope of the present invention as defined in the attached claims.Although the present invention has been described here with reference to certain structures, materials and embodiments, the invention is not understood to be limited to the details disclosed herein, but extends to all functionally equivalent structures, methods and applications as they fall within the scope of the attached claims.

[0124] The invention is not limited to the embodiments described above, and various variations and modifications may be possible without deviating from the scope of the invention.

Claims

[1] Method for placing a workpiece (3) on a measuring device (1; 1A; 1B; 1C) wherein the workpiece (3) is placed on a table (2) of a measuring device (1; 1A; 1B; 1C), the method comprising: Using a holding device (4) which is able to hold the workpiece (3) above the table (2); Using an adjustment device (49) which is able to raise and lower an upper surface of the table (2); Holding the workpiece (3) above the table (2) with the holding device (4); Lifting the upper surface of the table (2) with the adjusting device (49) to bring the upper surface of the table (2) into contact with a lower surface of the workpiece (3); and Releasing the holding device (4) from the workpiece (3) after the load of the workpiece (3) has been transferred to the table (2). [2] Method for placing a workpiece (3) on the measuring device (1; 1A; 1B; 1C) according to claim 1, wherein an operation in which the load of the workpiece (3) is transferred to the table (2) is an operation which, after lifting the table (2) and contacting the table (2) with the lower surface of the workpiece (3), continues to lift the table (2) and transfers the load of the workpiece (3) to the table (2). [3] Method for placing a workpiece (3) on the measuring device (1; 1A; 1B; 1C) according to claim 1 or 2, wherein: the workpiece (3) is held above the table (2) by the holding device (4), with the table (2) assuming a reference position, the upper surface of the table (2) is raised from the reference position by the adjusting device (49) and brought into contact with the lower surface of the workpiece (3), after the load of the workpiece (3) has been transferred to the table (2), the hold of the holding device (4) is released, and the upper surface of the table (2) is lowered by the adjustment device (49) and returned to the reference position. [4] Method for placing a workpiece (3) on the measuring device (1; 1A; 1B; 1C) according to claim 3, wherein: the upper surface of the table (2) is lowered by the adjustment device (49) to a waiting position which is lower than the reference position, the workpiece (3) is held by the holding device (4) in a position above the table (2) and lower than the reference position, the upper surface of the table (2) is raised from the waiting position by the adjusting device (49) and brought into contact with the lower surface of the workpiece (3), after the load of the workpiece (3) has been transferred to the table (2), the hold of the holding device (4) is released, and the upper surface of the table (2) is raised by the adjusting device (49) and returned to the reference position. [5] Computer program product which, when loaded and executed on a suitable system, is able to perform the steps according to one of the preceding procedures. [6] Measuring device comprising: a table (2) with a top surface on which a workpiece (3) can be placed, wherein the table (2) is installed on a base (9); a measuring device configured to measure the workpiece (3) placed on the upper surface; an adjustment device (49) which is installed in an area between the upper surface of the table (2) and the base (9) and is configured to raise and lower the upper surface relative to the base (9); a holding device (4) which is able to hold the workpiece (3) above the table (2); and a control or regulation (61) configured to control or regulate the adjustment device (49) such that the upper surface of the table (2) is raised relative to the workpiece (3) in a state in which the workpiece (3) is held above the upper surface by the holding device (4), so that the upper surface of the table (2) is brought into contact with the lower surface of the workpiece (3), and so that after the load of the workpiece (3) has been transferred from the table (2), the holding device (4) on the workpiece (3) is released. [7] Measuring device according to claim 6, wherein: the adjustment device (49) comprises: a vibration damping table (40) arranged between the table (2) and the base (9), the vibration damping table (40) comprising: a lower surface element (41) which is arranged at the base (9); an upper surface element (42) which holds the table (2); and at least one gas spring (43) which is arranged on the lower surface element (41) and holds the upper surface element (42); a gas line (54) which supplies gas to at least one gas spring (43); and a control or regulating valve (75, 77) which is configured to control or regulate the gas supply to the gas line (54), and the control (61) is configured to control operations of the adjustment device (49) by controlling or regulating the gas supply to the gas spring (43) using the control valve (75, 77). [8] Measuring device according to claim 7, wherein: the vibration damping table (40) has a tilt adjustment function and includes: several gas springs (43) which are installed between the upper surface element (42) and the lower surface element (41); and a control valve (45) which is connected to each of the gas springs (43), wherein the control valve (45) adds gas from the gas line (54) when the gas springs (43) are compressed, and releases gas from the gas springs (43) when the gas springs (43) are extended, the adjusting device (49) comprises: the vibration damping table (40); and a valve opening / closing control (61) configured to forcibly open and close the control valve (45), and wherein the control (61) is configured to control the gas supply to the gas springs (43) by forcibly opening and closing the control valve (45) using the valve opening / closing control (61). [9] Measuring device according to any one of the preceding claims 6 to 8, wherein the adjusting device (49) is a lifting / lowering mechanism which is arranged on the table (2) and is configured to hold the upper surface of the table (2) so that it is able to raise and lower itself.

Images