Three-dimensional measurement probe

Abstract

To provide a three-dimensional measurement probe that can accurately measure shape of a surface of an object being measured.SOLUTION: A three-dimensional measurement probe 1 comprises: a movable body 10 having a stylus 11 that contacts a surface of an object to be measured; a holding mechanism 20 that holds the movable body 10 so that the movable body 10 can move in a uniaxial direction; a case 30 that houses the movable body 10 and holding mechanism 20; and a vibration damping mechanism 40 that dampens vibrations of the movable body 10. Further, the vibration damping mechanism 40 comprises: a pin 41 that moves in the uniaxial direction in conjunction with movement of the movable body 10; and a gel 42 having a first plane 42a and a second plane 42b that are opposed to each other in the uniaxial direction. The first plane 42a and the second plane 42b are exposed surfaces exposed to an air layer, and the pin 41 is inserted into the gel 42 in the uniaxial direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a three-dimensional measurement probe. [Background technology]

[0002] There is known a three-dimensional shape measuring machine capable of measuring the three-dimensional shape of the surface of a measurement object. The three-dimensional shape measuring machine uses a three-dimensional measuring probe having a stylus that is brought into contact with the measurement object (for example, Patent Document 1).

[0003] In a three-dimensional shape measuring machine, the tip of the stylus of a three-dimensional measuring probe is brought into contact with the surface of the workpiece with a constant pressing force while the stylus traces the surface shape of the workpiece, and the displacement of the stylus is detected by a sensor to measure the three-dimensional shape of the workpiece. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-96518 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional three-dimensional measuring probes, it is sometimes difficult to measure the surface shape of a workpiece with high accuracy.

[0006] The present disclosure is devised to solve such problems, and has an object to provide a three-dimensional measuring probe capable of measuring the surface shape of a workpiece with high accuracy. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, one aspect of a three-dimensional measuring probe according to the present disclosure comprises a movable body having a stylus whose tip contacts the surface of a measured object, a holding mechanism that holds the movable body so that the movable body can move in a uniaxial direction, a case that houses the movable body and the holding mechanism, and a vibration damping mechanism for damping vibration of the movable body, wherein the vibration damping mechanism has a pin that moves in the uniaxial direction in conjunction with the movement of the movable body, and a gel having first and second planes facing away from each other in the uniaxial direction, the first and second planes being exposed surfaces exposed to an air layer, and the pin is inserted into the gel in the uniaxial direction. Effect of the Invention

[0008] According to the present disclosure, the shape of the surface of a measurement object can be measured with high accuracy. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a three-dimensional measuring probe according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the three-dimensional measuring probe according to the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view of the three-dimensional measuring probe according to the embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional perspective view showing a main part of the three-dimensional measuring probe according to the embodiment. [Diagram 5] FIG. 5 is a perspective view of a case in the three-dimensional measuring probe according to the embodiment. [Figure 6] FIG. 6 is a diagram showing a state in which a gel is formed in the three-dimensional measuring probe according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining the operation of the vibration damping mechanism in the three-dimensional measuring probe disclosed in Patent Document 1. In FIG. [Figure 8] FIG. 8 is a diagram for explaining the operation of the vibration damping mechanism in the three-dimensional measuring probe according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (How one aspect of the present disclosure was achieved) Before describing the embodiments of the present disclosure, the process by which one aspect of the present disclosure was achieved will be described.

[0011] There is known a three-dimensional measuring probe that measures the three-dimensional shape of the surface of a measurement object. For example, a three-dimensional measuring probe measures the shape of the surface of an optical component such as a lens, e.g., an aspheric lens, or a reflecting mirror, or measures the shape of the surface of a mold for molding a lens, etc.

[0012] When measuring the surface shape of a workpiece using a three-dimensional measuring probe, the tip of the stylus of the three-dimensional measuring probe is brought into contact with the surface of the workpiece and the stylus traces the surface shape of the workpiece. At this time, the stylus may vibrate, making it impossible to measure the surface shape of the workpiece with high accuracy. Stylus vibration is particularly likely to occur when the lens is soft or the mold is hard.

[0013] Therefore, a three-dimensional measuring probe capable of suppressing the vibration of the stylus has been proposed in the past. As this type of three-dimensional measuring probe, for example, Patent Document 1 discloses a contact-type probe having a vibration damping mechanism that damps the vibration of the stylus. The vibration damping mechanism disclosed in Patent Document 1 has a pin fixed to the stylus and a viscous fluid filled in a groove provided in a case (housing), and is configured such that the pin is inserted into the viscous fluid. With this configuration, when the pin moves vertically in the viscous fluid in conjunction with the vertical vibration of the stylus, the movement of the pin is regulated by the viscous fluid. As a result, the vibration of the stylus to which the pin is fixed can be damped, and therefore the vibration of the stylus can be suppressed.

[0014] However, in the contact probe disclosed in Patent Document 1, when the pin inserted in the viscous fluid moves up and down, the pin may separate from the viscous fluid, and therefore the vibration of the stylus cannot be stably damped. Therefore, the contact probe disclosed in Patent Document 1 may not be able to accurately measure the surface shape of the object to be measured.

[0015] Therefore, the inventors conducted intensive research into these problems and discovered that a vibration damping mechanism for damping stylus vibration can be achieved by inserting a pin that moves in conjunction with the vibration of the stylus into a gel with exposed front and back sides, thereby preventing the pin from coming off the gel, and thus arrived at one embodiment of the three-dimensional measuring probe disclosed herein.

[0016] Specifically, one aspect of the three-dimensional measuring probe according to the present disclosure comprises a movable body having a stylus whose tip contacts the surface of a measured object, a holding mechanism that holds the movable body so that the movable body can move in a uniaxial direction, a case that houses the movable body and the holding mechanism, and a vibration damping mechanism for damping vibration of the movable body, wherein the vibration damping mechanism has a pin that moves in the uniaxial direction in conjunction with the movement of the movable body, and a gel having first and second planes facing away from each other in the uniaxial direction, the first and second planes being exposed surfaces exposed to an air layer, and the pin is inserted into the gel in the uniaxial direction.

[0017] With this configuration, the vibration of the movable body can be damped by the vibration damping mechanism, thereby suppressing the vibration of the movable body. Moreover, since it is possible to prevent the pin from coming off the gel and being unable to dampen the vibration of the movable body, the vibration of the movable body can be damped stably. Therefore, the surface shape of the object to be measured can be measured with high accuracy.

[0018] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the pin may penetrate the gel.

[0019] With this configuration, it is possible to further prevent the pin from coming out of the gel when the pin moves in conjunction with the vibration of the movable body, and therefore it is possible to measure the surface shape of the object to be measured with even greater accuracy.

[0020] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the vibration damping mechanism has two of the pins and two of the gels, and when viewed from above, the two pins and the two gels are arranged so as to sandwich the stylus.

[0021] This configuration allows the vibration damping mechanisms to be arranged in a well-balanced manner on the left and right sides of the stylus, thereby efficiently damping the vibration of the movable body.

[0022] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the holding mechanism may include a bearing that supports the movable body, and a magnetic force generating mechanism that generates a magnetic force that levitates the movable body.

[0023] With this configuration, the movable body can be held magnetically, so the three-dimensional measuring probe can be a magnetically levitated probe. Therefore, the movable body can be held with a much weaker force than when the movable body is held in the axial direction by a spring member or the like. This makes it possible to reduce the measurement force when measuring an object having a three-dimensional shape, and to perform highly accurate measurement despite being a contact type. In particular, using a gas bearing for the bearing results in completely non-contact holding, which makes it easier for vibration to occur, but by holding the movable body magnetically, a small damping force can be added, so the vibration can be reduced.

[0024] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the case may be made of a magnetic material.

[0025] With this configuration, even if there is an external magnetic force such as a magnet outside the case, the magnetic flux due to this external magnetic force is absorbed by the case, so the surface shape of the object to be measured can be measured with high accuracy.

[0026] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the bearing may be a gas bearing.

[0027] With this configuration, the axis of the movable body can be held without contact, so there is no unstable damping such as static friction caused by contact-type holding, and ideal damping can be obtained using only the viscous resistance of the gel.

[0028] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the gel may be made of an ultraviolet curing resin.

[0029] With this configuration, a gel can be formed by applying liquid ultraviolet curing resin to a predetermined position and curing it with ultraviolet light.

[0030] In addition, in one aspect of the three-dimensional measuring probe according to the present disclosure, the gel is held in a holder fixed to the case, and the case is configured to be separable into two in the uniaxial direction at the position of the holder.

[0031] With this configuration, the liquid gel can be easily injected into a predetermined position in the holder using the dispenser and allowed to harden.

[0032] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims showing the highest concept of the present disclosure will be described as optional components.

[0033] Note that each figure is a schematic diagram and is not necessarily illustrated precisely. In addition, in each figure, the same reference numerals are given to substantially the same configurations, and duplicated explanations are omitted or simplified. In this specification, the terms "upper" and "lower" do not necessarily refer to the upper direction (vertically upward) and the lower direction (vertically downward) in absolute spatial recognition. In this specification and drawings, the X-axis, the Y-axis, and the Z-axis represent the three axes of a three-dimensional orthogonal coordinate system. The X-axis and the Y-axis are mutually orthogonal and are both orthogonal to the Z-axis. In this embodiment, the Z-axis direction is the vertical direction.

[0034] (Embodiment) First, the configuration of a three-dimensional measuring probe 1 according to an embodiment will be described with reference to Figs. 1 to 5. Fig. 1 is a perspective view of the three-dimensional measuring probe 1 according to the embodiment. Fig. 2 is a cross-sectional view of the three-dimensional measuring probe 1 according to the embodiment. Fig. 3 is a cross-sectional view of the three-dimensional measuring probe 1 according to the embodiment cut along a plane rotated 90° with respect to Fig. 2. Fig. 4 is a cross-sectional perspective view showing an enlarged view of a main part of the three-dimensional measuring probe 1 according to the embodiment.

[0035] The three-dimensional measuring probe 1 is a probe for measuring the three-dimensional shape of the surface of a measurement object. The measurement object measured by the three-dimensional measuring probe 1 is an object having a three-dimensional shape, and an example of the measurement object is an optical component such as a lens, such as an aspheric lens, or a reflecting mirror. Note that the measurement object measured by the three-dimensional measuring probe 1 is not limited to an optical component.

[0036] As shown in Figure 1, the three-dimensional measuring probe 1 comprises a movable body 10, a holding mechanism 20 that holds the movable body 10, a case 30 that houses the movable body 10 and the holding mechanism 20, and a vibration damping mechanism 40 (shown in Figure 3) for damping vibrations of the movable body 10.

[0037] The movable body 10 has a stylus 11 and a sliding shaft portion 12. The stylus 11 and the sliding shaft portion 12 are fixed together.

[0038] Stylus 11 is fixed to one end in the longitudinal direction of sliding shaft portion 12. The tip of stylus 11 contacts the surface of the object to be measured by three-dimensional measuring probe 1. Specifically, a tip ball 11a is provided at the tip of stylus 11, and tip ball 11a contacts the object to be measured.

[0039] 2, the sliding shaft portion 12 is a long cylindrical member. The sliding shaft portion 12 extends in the Z-axis direction. The sliding shaft portion 12 is supported by a holding mechanism 20 so as to be slidable in the Z-axis direction.

[0040] The holding mechanism 20 holds the movable body 10 so that the movable body 10 can move in one axial direction. In this embodiment, the one axial direction in which the movable body 10 moves is the Z-axis direction, and therefore the holding mechanism 20 holds the movable body 10 so that the movable body 10 can move in the Z-axis direction.

[0041] The holding mechanism 20 has a bearing 21 that slidably supports the movable body 10, and a magnetic force generating mechanism 22 that generates a magnetic force that levitates the movable body 10.

[0042] The bearing 21 holds the movable body 10 so that the movable body 10 can move in one axial direction. Specifically, the bearing 21 supports the sliding shaft portion 12 of the movable body 10. That is, the sliding shaft portion 12 slides relative to the bearing 21. In this embodiment, the bearing 21 is an air bearing. Compressed air is fed into the bearing 21 from a tube 50 (shown in FIG. 6). This allows the sliding shaft portion 12 to slide in the Z-axis direction without friction with the bearing 21 due to the film of compressed air.

[0043] The magnetic force generating mechanism 22 generates a magnetic force that levitates the movable body 10 in the Z-axis direction (gravity direction), and imparts a weak spring constant to the movable body 10. In this manner, the movable body 10 is in a floating state due to the magnetic force generated by the magnetic force generating mechanism 22.

[0044] The magnetic force generating mechanism 22 has a permanent magnet 22a, a first yoke 22b, a second yoke 22c, and a magnetic pin 22d. The first yoke 22b is located above the permanent magnet 22a, and the second yoke 22c is located below the permanent magnet 22a (on the stylus 11 side). In other words, the permanent magnet 22a is sandwiched between the first yoke 22b and the second yoke 22c in the Z-axis direction.

[0045] The first yoke 22b, the second yoke 22c, and the magnetic pin 22d are magnetic bodies of a predetermined shape made of a magnetic material. In this embodiment, the first yoke 22b located on the upper side is a single magnetic body having a through hole in the center and extending in the X-axis direction. On the other hand, the second yoke 22c located on the lower side is made of a pair of magnetic bodies arranged in the X-axis direction. The magnetic pin 22d is a magnetic piece extending in the X-axis direction. As shown in FIG. 2, the tip portion of the magnetic pin 22d is sandwiched between the pair of magnetic bodies constituting the second yoke 22c in the X-axis direction. The tip portion of the magnetic pin 22d faces the second yoke 22c with a gap in the X-axis direction. As an example, the first yoke 22b, the second yoke 22c, and the magnetic pin 22d are made of iron.

[0046] Moreover, the permanent magnets 22a are disposed between the first yoke 22b and each of the pair of magnetic bodies constituting the second yoke 22c. That is, in the present embodiment, two permanent magnets 22a are provided.

[0047] The permanent magnet 22a, the first yoke 22b, and the second yoke 22c are held by a first holder 60. Meanwhile, the magnetic pin 22d is held by a second holder 70. The first holder 60 and the second holder 70 are made of a metal material such as aluminum, but are not limited thereto, and may be made of a resin material.

[0048] The first holder 60 is fixed to the case 30. On the other hand, the second holder 70 is fixed to the movable body 10. Therefore, the first holder 60 does not move even if the movable body 10 moves, but when the movable body 10 moves in the Z-axis direction, the second holder 70 moves in the Z-axis direction in conjunction with the movement of the movable body 10. Therefore, the permanent magnet 22a, the first yoke 22b, and the second yoke 22c held by the first holder 60 do not change positions even if the movable body 10 moves, but the magnetic pin 22d held by the second holder 70 moves in the Z-axis direction in conjunction with the movement of the movable body 10.

[0049] The magnetic force generating mechanism 22 thus configured forms a magnetic circuit with the permanent magnet 22a, the first yoke 22b, the second yoke 22c, and the magnetic pin 22d. Specifically, the permanent magnet 22a, the first yoke 22b, and the second yoke 22c form a magnetic circuit with the magnetic pin 22d in a non-contact manner. In this case, the magnetic flux generated from one of the two permanent magnets 22a passes through one of the two second yokes 22c, passes through the magnetic pin 22d arranged with a gap between the second yoke 22c, passes through the other of the two second yokes 22c arranged with a gap between the magnetic pin 22d, adds the magnetic flux generated from the other of the two permanent magnets 22a, passes through the first yoke 22b, and returns to the original one permanent magnet 22a. With the magnetic circuit thus formed, the magnetic force generating mechanism 22 generates a magnetic force that prevents the movable body 10 from moving in the Z-axis direction (one axis direction) and also generates a magnetic force that prevents the movable body 10 from moving in the rotational direction around the Z axis. As a result, the movable body 10 is held in a floating state.

[0050] The case 30 is a housing that houses the movable body 10 and the holding mechanism 20. A part of the movable body 10 is exposed from the lower end of the case 30. Specifically, the case 30 houses the stylus 11 and the sliding shaft portion 12 of the movable body 10, but does not house the stylus 11. That is, the stylus 11 is exposed from the case 30. The case 30 also houses the bearing 21 and the magnetic force generating mechanism 22 of the holding mechanism 20. The case 30 further houses the first holder 60 and the second holder 70. In this embodiment, the case 30 is made of a magnetic material. As an example, the case 30 is made of iron, which is a ferromagnetic material. The case 30 is an outer shell member that constitutes the outer shell of the three-dimensional measuring probe.

[0051] The case 30 is configured so as to be separable into two in one axial direction (Z-axis direction) in which the movable body 10 moves at the position of the first holder 60. Specifically, the case 30 is configured by a first case part 31 and a second case part 32. The first case part 31 and the second case part 32 are connected and fixed by screws.

[0052] The first case part 31 is located below the second case part 32 in the Z-axis direction. In other words, the second case part 32 is located above the first case part 31 in the Z-axis direction. The first case part 31 houses the bearing 21 of the movable body 10. The bearing 21 is fixed to the first case part 31. The first holder 60 is fixed to the case 30. Specifically, the first holder 60 is fixed to the first case part 31.

[0053] Furthermore, as described above, if the case 30 is made of iron, which is a magnetic body, the case 30 may affect the magnetic circuit formed by the magnetic force generating mechanism 22, which may reduce the restoring force of the movable body 10 that is levitated by the magnetic force generated by the magnetic force generating mechanism 22. For example, the magnetic flux generated by the magnetic force generating mechanism 22 may be unintentionally absorbed by the case 30 made of a magnetic body, which may prevent the magnetic force generating mechanism 22 from forming a predetermined magnetic circuit.

[0054] Therefore, in this embodiment, as shown in FIG. 5, the first case part 31 is provided with a dug part 31a by dug a part of the first case part 31 toward the stylus 11 side. FIG. 5 is a perspective view of the case 30 in the three-dimensional measuring probe 1. The dug part 31a is provided between the magnetic force generating mechanism 22 and the inner wall of the first case part 31. By providing the dug part 31a in this manner, a gap (air layer) exists between the magnetic force generating mechanism 22 and the inner wall of the first case part 31, so that even if the case 30 is made of iron, which is a magnetic body, it is possible to suppress the case 30 from affecting the magnetic circuit formed by the magnetic force generating mechanism 22. In other words, the dug part 31a functions as a magnetic resistance, so that it is possible to suppress the magnetic flux generated by the magnetic force generating mechanism 22 from being absorbed by the case 30.

[0055] The vibration damping mechanism 40 has a function of damping vibration of the movable body 10. As shown in Figures 3 and 4, the vibration damping mechanism 40 has a pin 41 and a gel 42.

[0056] The pin 41 is fixed to the movable body 10. Therefore, the pin 41 moves in one axial direction, which is the direction in which the movable body 10 moves, in conjunction with the movement of the movable body 10. Specifically, when the movable body 10 moves in the Z-axis direction, the pin 41 also moves in the Z-axis direction. In this embodiment, the pin 41 is fixed to a second holder 70 fixed to the movable body 10. That is, the pin 41 is not directly fixed to the movable body 10, but is fixed to the movable body 10 via the second holder 70. The pin 41 may be directly fixed to the movable body 10. The pin 41 may be made of a non-magnetic material such as stainless steel. The pin 41 is a cylindrical and long rod-like member.

[0057] The gel 42 is held by the first holder 60. Specifically, the gel 42 is fixed to the first holder 60 by being fitted into a through hole 61 provided in the first holder 60. The through hole 61 of the first holder 60 has a circular shape in top view. Therefore, the outer shape of the gel 42 fitted into the through hole 61 is also circular. Specifically, the gel 42 is disc-shaped, and the height (thickness) of the gel 42 is smaller than the diameter of the gel 42. Since the first holder 60 that holds the gel 42 is fixed to the case 30, the position of the gel 42 does not change even if the movable body 10 moves.

[0058] As shown in FIG. 4, the gel 42 has a first plane 42a and a second plane 42b that face each other in one axial direction (Z-axis direction) in which the movable body 10 moves. Specifically, the first plane 42a is the upper surface of the gel 42 in the Z-axis direction, and the second plane 42b is the lower surface of the gel 42 in the Z-axis direction. In this embodiment, the first plane 42a and the second plane 42b are parallel to each other. The first plane 42a and the second plane 42b are exposed surfaces that are exposed to the air layer. In other words, there is a space region that is an air layer above the first plane 42a and below the second plane 42b, and the first plane 42a and the second plane 42b are exposed to the air layer.

[0059] The pin 41 is inserted into the gel 42 in one axial direction (Z-axis direction) which is the direction in which the movable body 10 moves. Specifically, the pin 41 is inserted into the gel 42 so as to be pushed up from the second flat surface 42b (lower surface) of the gel 42. The pin 41 inserted into the gel 42 is fixed to the gel 42.

[0060] In this embodiment, the pin 41 penetrates the gel 42. In this case, the upper end surface of the pin 41 is flush with the first plane 42a of the gel 42, and the pin 41 extends downward from the gel 42. In other words, the pin 41 protrudes downward from the second plane 42b of the gel 42.

[0061] The pin 41 may also protrude from the first flat surface 42a of the gel 42. That is, the pin 41 may penetrate the gel 42 so as to protrude from both sides of the gel 42. The pin 41 may not necessarily penetrate the gel 42. That is, the pin 41 may be inserted into the gel 42 so that the upper end surface of the pin 41 is present inside the gel 42.

[0062] The vibration damping mechanism 40 has two pins 41 and two gels 42. Therefore, the first holder 60 has two through holes 61 in which the gels 42 are fixed. The two pins 41 and the two gels 42 are arranged to sandwich the stylus 11 in a top view. In other words, the two pins 41 and the two gels 42 are arranged at 180° intervals around the axis of the movable body 10 (sliding shaft portion 12). In other words, in a cross-sectional view, a pair of vibration damping mechanisms 40 are provided symmetrically.

[0063] The gel 42 is made of a resin material. In the present embodiment, the gel 42 is made of an ultraviolet curing resin. In the present embodiment, an ultraviolet curing silicone gel (for example, "3168" manufactured by ThreeBond Co., Ltd.) is used as the gel 42.

[0064] When placing the gel 42 in the through hole 61 of the first holder 60, as shown in Fig. 6, the first case part 31 and the second case part 32 are separated, and the liquid gel 42 before hardening is injected into the through hole 61 of the first holder 60 with the dispenser 100 while the pin 41 is inserted in the through hole 61, and the liquid gel 42 is hardened by irradiating it with ultraviolet light. This allows the gel 42 with the pin 41 inserted therein to be formed in the through hole 61 of the first holder 60, and allows the gel 42 and the pin 41 to be fixed. Note that Fig. 6 is a diagram showing a state in which the gel 42 is formed in the three-dimensional measuring probe 1 according to the embodiment.

[0065] Furthermore, when the liquid gel 42 is injected into the through hole 61, the pin 41 is inserted into the through hole 61, so the liquid gel 42 does not immediately drip from the through hole 61 when the liquid gel 42 is injected into the through hole 61. However, if the gap between the inner surface of the through hole 61 and the pin 41 becomes too large, the liquid gel 42 may drip. For this reason, the hole diameter (diameter) of the through hole 61 is preferably 10 times or less the diameter of the columnar pin 41. In this embodiment, the gel 42 is formed with a height (thickness) of 0.5 mm. In this case, the hole diameter (diameter) of the through hole 61 is φ1.5 mm, and the diameter of the pin 41 is φ0.3 mm. In other words, the hole diameter of the through hole 61 is 5 times the diameter of the pin 41.

[0066] The three-dimensional measuring probe 1 configured in this manner is used in a three-dimensional shape measuring machine. When the shape of the surface of a measured object is measured using this three-dimensional shape measuring machine, the tip of the stylus 11 of the three-dimensional measuring probe 1 is brought into contact with the surface of the measured object with a constant pressing force while tracing the surface shape of the measured object, and the displacement of the stylus 11 in the Z-axis direction is detected by a displacement detection mechanism, thereby measuring the three-dimensional shape of the measured object. The displacement detection mechanism includes, for example, a mirror 80 fixed to the movable body 10, a light source that emits measurement light such as laser light, and a photodetector that detects the measurement light reflected by the mirror 80, and the displacement of the movable body 10 in the Z-axis direction is detected by the photodetector.

[0067] In the present embodiment, mirror 80 is held by second holder 70 fixed to movable body 10. Specifically, mirror 80 is disposed on magnetic pin 22d fixed to second holder 70. Although not shown, a light source and a photodetector may be provided in three-dimensional measuring probe 1, or in a three-dimensional shape measuring machine to which three-dimensional measuring probe 1 is attached.

[0068] Next, the action and effect of the three-dimensional measuring probe 1 according to the embodiment will be described in comparison with the three-dimensional measuring probe 1X disclosed in Patent Document 1 with reference to Figures 7 and 8. Figure 7 is a diagram for explaining the operation of a vibration damping mechanism 40X in the three-dimensional measuring probe 1X disclosed in Patent Document 1. Figure 8 is a diagram for explaining the operation of a vibration damping mechanism 40 in the three-dimensional measuring probe 1 according to the embodiment.

[0069] As shown in FIG. 7(a), the vibration damping mechanism 40X in the three-dimensional measuring probe 1X disclosed in Patent Document 1 has a pin 41X fixed to a stylus and a viscous fluid 42X filled in a groove 61X provided in a case 60X, and is configured so that the pin 41X is inserted into the viscous fluid 42X.

[0070] With this configuration, in the vibration damping mechanism 40X disclosed in Patent Document 1, when the stylus vibrates in the up-down direction, the pin 41X vibrates in the up-down direction within the viscous fluid 42X in conjunction with the up-down vibration of the stylus, as shown in Fig. 7(b). At this time, the movement of the pin 41X is restricted by the viscous fluid 42X, so the vibration of the stylus to which the pin 41X is fixed is dampened, and the vibration of the stylus can be suppressed.

[0071] However, in the vibration damping mechanism 40X disclosed in Patent Document 1, as shown in FIG. 7(c), when the vibration of the stylus becomes large, the pin 41 may be separated from the viscous fluid 42X when the pin 41X inserted into the viscous fluid 42X moves upward. In other words, the pin 41X may come off from the viscous fluid 42X. For this reason, the vibration damping mechanism 40X disclosed in Patent Document 1 cannot stably damp the vibration of the stylus. In particular, it is desirable to make the depth of the pin 41X inserted into the viscous fluid 42X as shallow as possible, but if the depth of the pin 41X is made too shallow, the pin 41X may come off from the viscous fluid 42X when the pin 41X moves upward when the stylus vibrates.

[0072] In contrast, as shown in (a) of Figure 8, in the vibration damping mechanism 40 of the three-dimensional measuring probe 1 according to this embodiment, a pin 41 that moves in conjunction with the movement of the movable body 10 is inserted into a gel 42 having both a first plane 42a and a second plane 42b exposed.

[0073] With this configuration, when the pin 41 vibrates in conjunction with the vibration of the movable body 10 (stylus 11) of the three-dimensional measuring probe 1, since the pin 41 is inserted into the gel 42, the movement of the pin 41 is restricted by the gel 42. This makes it possible to attenuate the vibration of the movable body 10 (stylus 11), and therefore to suppress the vibration of the movable body 10 (stylus 11).

[0074] For example, when the object to be measured by the three-dimensional measuring probe 1 is a soft lens, the spring component of the movable body 10 generates high-frequency vibrations in the movable body 10. However, by damping the movable body 10 with a vibration damping mechanism 40 using gel 42, as in the three-dimensional measuring probe 1 of this embodiment, the high-frequency vibrations can be effectively suppressed.

[0075] However, if the damping force (damping action) of the vibration damping mechanism 40 becomes too large, there is a risk that the movable body 10 may vibrate in the low frequency range, so it is preferable that the damping force of the vibration damping mechanism 40 is set within an appropriate range. In this case, the damping force of the vibration damping mechanism 40 is set to 1×10 -4 It is a predetermined value equal to or less than N, which is very small. If the damping force by the vibration damping mechanism 40 is Fs, the damping force Fs can be simply expressed by the following (Equation 1), and it is preferable that the damping force Fs is in the range of 0.2 to 2 times the predetermined value.

[0076]

number

[0077] In addition, in (Equation 1), D1 is the hole size (diameter) of the through-hole 61 in which the gel 42 is placed, D2 is the diameter of the cylindrical pin 41, H is the height (thickness) of the gel 42, V is the moving speed of the pin 41, and μ is the viscosity coefficient of the gel 42. As an example, as described above, D1=φ1.5 mm, D2=φ0.3 mm, and H=0.5 mm.

[0078] Furthermore, in the vibration damping mechanism 40 of the three-dimensional measuring probe 1 according to this embodiment, when the pin 41 moves upward as shown in FIG. 8(b) in conjunction with the vibration of the movable body 10 (stylus 11), the gel 42 is pulled upward by the pin 41. Also, when the pin 41 moves downward as shown in FIG. 8(c) in conjunction with the vibration of the movable body 10 (stylus 11), the gel 42 is pulled downward by the pin 41. In this way, whether the pin 41 moves upward or downward, the gel 42 is pulled by the pin 41, so that the pin 41 is unlikely to come off the gel 42. In this case, even if the contact width between the gel 42 and the pin 41 is small, the gel 42 and the pin 41 are unlikely to come off when the pin 41 moves up and down.

[0079] In this way, the three-dimensional measuring probe 1 according to the present embodiment can prevent the pin 41 from coming out of the gel 42, which makes it impossible to damp the vibration of the movable body 10, and can therefore stably damp the vibration of the movable body 10. Therefore, the shape of the surface of the object to be measured can be measured with high accuracy.

[0080] Furthermore, in three-dimensional measuring probe 1 according to this embodiment, pin 41 penetrates gel .

[0081] This configuration can further prevent the pin 41 from coming off the gel 42 when the pin 41 moves in conjunction with the vibration of the movable body 10. Therefore, the shape of the surface of the object to be measured can be measured with even greater accuracy.

[0082] Furthermore, in the three-dimensional measuring probe 1 of this embodiment, the vibration damping mechanism 40 has two pins 41 and two gels 42, and when viewed from above, the two pins 41 and the two gels 42 are arranged so as to sandwich the stylus 11.

[0083] This configuration allows the vibration damping mechanisms 40 to be arranged in a well-balanced manner on the left and right sides of the stylus 11. This allows the vibration of the movable body 10 (stylus 11) to be efficiently damped.

[0084] Moreover, in the three-dimensional measuring probe 1 according to this embodiment, a holding mechanism 20 that holds the movable body 10 has a bearing 21 that supports the movable body 10, and a magnetic force generating mechanism 22 that generates a magnetic force that levitates the movable body 10. In other words, the three-dimensional measuring probe 1 according to this embodiment is a magnetic levitation type probe.

[0085] With this configuration, the movable body 10 can be held with a very weak force compared to the case where the movable body 10 is elastically held by a spring member such as a hanging spring, so that the measurement force when measuring an object having a three-dimensional shape can be reduced, and a highly accurate measurement can be performed even though it is a contact type. In particular, if the bearing 21 is a gas bearing such as an air bearing, the object is held completely non-contact and vibrations are likely to occur, but by holding the movable body 10 magnetically, a small damping force can be added, so that the vibrations can be reduced. Moreover, the three-dimensional measuring probe 1 according to this embodiment is a magnetic levitation gel type probe using the gel 42 in the vibration damping mechanism 40 as described above. This makes it possible to effectively suppress the vibrations of the movable body 10.

[0086] Furthermore, in the three-dimensional measuring probe 1 according to this embodiment, the movable body 10 is held by the magnetic force generating mechanism 22 which forms a magnetic circuit, so if an external magnetic force such as a magnet is present outside (around) the case 30, the external magnetic force may affect the magnetic circuit formed by the magnetic force generating mechanism 22, making it impossible to accurately measure the shape of the surface of the object to be measured. For example, if the case 30 is made of aluminum, magnetic flux due to the external magnetic force may pass through the case 30, and the magnetic circuit formed by the magnetic force generating mechanism 22 may be affected by the external magnetic force.

[0087] Therefore, in three-dimensional measuring probe 1 according to the present embodiment, case 30 is made of a magnetic material.

[0088] With this configuration, even if an external magnetic force such as a magnet exists outside the case 30, the magnetic flux due to the external magnetic force is absorbed by the case 30 and is prevented from reaching the inside of the case 30. In other words, the case 30 functions as a magnetic shield member. As a result, even if an external magnetic force exists outside the case 30, the external magnetic force can be prevented from affecting the magnetic circuit formed by the magnetic force generating mechanism 22, so that the shape of the surface of the object to be measured can be measured with high accuracy.

[0089] Furthermore, in three-dimensional measuring probe 1 according to the present embodiment, gel 42 of vibration damping mechanism 40 is made of ultraviolet curing resin.

[0090] With this configuration, the gel 42 can be formed by applying a liquid ultraviolet curing resin to a predetermined position and curing it with ultraviolet light.

[0091] In the three-dimensional measuring probe 1 according to the above embodiment, the case 30 is configured to be separable into two in one axial direction (Z-axis direction) along which the movable body 10 moves at the position of the first holder 60 where the gel 42 is held. Specifically, the case 30 can be separated into a first case part 31 and a second case part 32.

[0092] When the gel 42 is made of a photocurable resin such as an ultraviolet curable resin, it is necessary to cure the photocurable resin by irradiating light. At this time, since the case 30 is separated into the first case part 31 and the second case part 32, the photocurable resin can be easily injected into the through hole 61 of the first holder 60 by the dispenser 100 as shown in Fig. 6, and the injected photocurable resin can be easily cured by light such as ultraviolet light to form the gel 42. In other words, by making the case 30 separable into the top and bottom, the workability of forming the gel 42 in the first holder 60 in the case 30 can be improved.

[0093] Moreover, as described above, the damping force of the vibration damping mechanism 40 is 1×10 -4 This very small damping force is required to be generated with high precision by the vibration damping mechanism 40. By using the dispenser 100, a fixed amount of the ultraviolet curing agent can be easily injected into the through-hole 61.

[0094] (Modification) Although the three-dimensional measuring probe and the like according to the present disclosure have been described above based on the embodiments, the present disclosure is not limited to the above-described embodiments.

[0095] For example, the present invention includes forms obtained by applying various modifications conceived by a person skilled in the art to the above-mentioned embodiments, and forms realized by arbitrarily combining the components and functions in the embodiments within the scope of the present invention. In addition, the present invention also includes any combination of two or more claims among the multiple claims described in the claims at the time of filing of this application, within the scope of technical compatibility. For example, when a dependent claim described in the claims at the time of filing of this application is made into a multiple claim or multiple multiple claim so as to cite all of the higher claims within the scope of technical compatibility, the present invention also includes all combinations of claims included in the multiple claim or multiple multiple claim. [Industrial Applicability]

[0096] The technology disclosed herein is useful as a three-dimensional measuring probe for measuring objects to be measured such as optical components or molds. [Explanation of symbols]

[0097] 1 3D Measuring Probe 10 Movable body 11 Stylus 11a Tip ball 12 Sliding shaft 20 Retention mechanism 21 Bearings 22 Magnetic force generation mechanism 22a permanent magnet 22b 1st York 22c 2nd York 22d Magnetic pin 30 cases 31 First case part 32 Second case part 31a Excavation 40 Vibration damping mechanism 41 pin 42 Gel 42a 1st plane 42b 2nd plane 50 tubes 60 First Holder 61 Through hole 70 Second Holder 80 Mirror 100 Dispenser

Claims

1. a movable body having a stylus whose tip contacts the surface of the object to be measured; a holding mechanism for holding the movable body so that the movable body can move in one axial direction; a case that houses the movable body and the holding mechanism; a vibration damping mechanism for damping vibration of the movable body, the vibration damping mechanism includes a pin that moves in the uniaxial direction in conjunction with the movement of the movable body, and a gel having a first plane and a second plane opposed to each other in the uniaxial direction; the first plane and the second plane are exposed surfaces exposed to an air layer, The pin is inserted into the gel in the uniaxial direction. 3D measuring probe.

2. The pin penetrates the gel.

2. The three-dimensional measuring probe of claim 1.

3. the vibration damping mechanism includes two pins and two gels, When viewed from above, the two pins and the two gels are arranged to sandwich the stylus.

3. A three-dimensional measuring probe according to claim 1 or 2.

4. The holding mechanism includes a bearing that supports the movable body, and a magnetic force generating mechanism that generates a magnetic force that levitates the movable body.

3. A three-dimensional measuring probe according to claim 1 or 2.

5. The case is made of a magnetic material.

5. The three-dimensional measuring probe according to claim 4.

6. The bearing is a gas bearing.

5. The three-dimensional measuring probe according to claim 4.

7. The gel is made of an ultraviolet curable resin.

3. A three-dimensional measuring probe according to claim 1 or 2.

8. The gel is held in a holder fixed to the case, The case is configured to be separable into two in the one axial direction at the position of the holder.

8. A three-dimensional measuring probe according to claim 7.

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