JP2013007617A - Stylus type surface shape measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stylus type surface shape measuring instrument capable of simply attaching/detaching a cover member without exerting influence on a displacement sensor or the like.SOLUTION: The stylus type surface shape measuring instrument includes a storage case 1 for storing a first support member 2 for supporting a differential transformer and a second support member 15 for supporting a probe 16. The storage case 1 is composed of a case body 1a and a cover member 1b and two cover fixing magnets are adjacently arranged in the case body 1a so that the magnetic poles of these magnets are opposed to each other. A peripheral wall composed of a ferromagnetic material is formed so as to surround the side faces and one end face of the cover member fixing magnets. A portion to be adsorbed composed of a ferromagnetic material is formed on a position of the cover member 1b opposed to the cover member fixing magnets when the cover member 1b is attached to the case body 1a, and when the cover member 1b is attached to the case body 1a, the peripheries of the cover fixing magnets are surrounded by the peripheral wall of the case body 1a and the part to be adsorbed of the cover member 1b.

Description

  The present invention relates to a stylus type surface shape measuring instrument using a differential transformer as a displacement sensor, and more particularly to a stylus type surface shape measuring instrument having a configuration in which a lid member can be easily attached and detached for probe replacement.

9 is a schematic side view showing the configuration of a stylus type surface shape measuring instrument using a differential transformer as a displacement sensor, and FIG. 10 is a schematic bottom view of the stylus type surface shape measuring instrument shown in FIG. Yes.
In the figure, reference numeral 51 denotes a rod-shaped first support member. The first support member 51 includes a fulcrum needle attachment member 52 extending in the left and right lateral directions at an intermediate portion thereof, and two fulcrum needles 53 are attached to both ends of the fulcrum needle attachment member 52. These two fulcrum needles 53 are supported by two fulcrum receiving members 54, whereby the first support member 51 is swingably supported by the fulcrum receiving member via the fulcrum needles 53. A measuring element of the displacement sensor 55, that is, a core 56 is attached to one end of the first support member 51. The displacement sensor 55 is composed of a differential transformer that generates an electrical signal in response to the vertical displacement of the probe, and includes a coil 57.
The other end of the first support member 51 is provided with a core 59 of a needle pressure generator 58 that applies a needle pressure to the probe, and the needle pressure generator 58 includes a coil 60. The core 59 is made of a high magnetic permeability member disposed at a position shifted in the axial direction from the center of the coil 60.
Two magnets 61 are embedded in the lower surface of the first support member 51. These magnets 61 are arranged in the front-rear direction around a line connecting the two fulcrum needles 53 in the first support member 51.
In the figure, reference numeral 62 denotes a rod-like second support member, and a probe 63 is attached downward at the tip, and the other end is constituted by a high permeability member 64.
With the above-described configuration, the magnet 61 embedded in the first support member 51 constituting the sensor attracts and fixes the high permeability member 64 of the second support member 62 including the probe 63, and includes the probe 63. The second support member 62 is detachable from the first support member 51 constituting the sensor (see [Patent Document 1] JP 2007-17296 A).
As shown in FIG. 9 and FIG. 10, in a stylus type surface shape measuring instrument using a differential transformer as a displacement sensor, the probe 63 and the core 56 of the displacement sensor 55 are usually connected by a rod-like object to support them. The probe is installed away from the fulcrum, and the vertical movement of the probe on the sample surface is transmitted to the displacement sensor 55.
The displacement is measured with low noise and high accuracy by a digital lock-in amplifier using a digital signal processor DSP, for example. In order to bring the probe 63 into contact with the sample, an electric current is passed through the coil 60 of the needle pressure generator 58 in FIG. 9 to press the probe 63 against the sample.
In the above-mentioned stylus type surface shape measuring instrument, the probe 63 is a consumable item and needs to be replaced. Therefore, as described above, the magnet 61 embedded in the first support member 51 including the displacement sensor 55 and the like is configured to attract and fix the high permeability member 64 of the second support member 62 including the probe 63. Thus, the second support member 62 including the probe 63 can be detached from the first support member 51 including the displacement sensor 55 and the like.
The first support member 51 and the second support member 62 in the stylus type surface shape measuring device configured as described above prevent electromagnetic noise from the outside, prevent winds that affect measurement, It is covered with a metal case 65 for the purpose of protecting the parts.
The case 65 includes an upper case body 66 including a fulcrum receiving member 54 and a lid member 67. The lid member 67 can be attached to and detached from the upper case body 66 so that the expendable probe 63 can be replaced. It is configured.

JP2007-17296

The stylus type surface shape measuring instrument configured as described above is used when, for example, a screw is used to fix the lid member 67 to the upper case body 66 because the size of the case 65 is as small as several centimeters. The screw is also a small screw of about M2.
For this reason, if, for example, a screw is used to fix the lid member 67 to the upper case main body 66, it takes time to attach and detach it.
In particular, the stylus type surface shape measuring instrument is often used in a clean room, and handling a small screw of about M2 with clean gloves is very inefficient.
In order to simplify the attachment and detachment of the lid member 67, a method of using a magnet for fixing the lid member 67 is also conceivable. However, the differential transformer of the displacement sensor 55 is sensitive to an external magnetic field because it measures magnetic flux, Further, since the distance from the lid member 67 to the displacement sensor 55 is only about 1 cm, it is easily affected by the magnetic field of the magnet.
The needle pressure generator 58 places a ferromagnetic core 59 at the end of the coil 60 and draws the core 59 into the center of the coil by using the gradient of the magnetic field there. Therefore, this mechanism is also susceptible to magnetic fields generated from others.
Further, in order to make the probe 63 detachable, a high permeability member 64 is provided on the second support member 62 including the probe 63, and the magnet 61 provided on the first support member 51 including the displacement sensor 55 is used. The second support member 62 is fixed to the first support member 51. The high permeability member 64 in the second support member 62 is also affected by a magnetic field generated elsewhere. When a force moment is generated around the fulcrum due to the force of the magnetic field, the force pressing the probe against the sample is affected. This type of step gauge, which has a force of pressing the probe against the sample of 0.03 mgf, also measures the step with the smallest force, so we want to avoid generating extra magnetic fields that can affect it.
As described above, if screws are used to fix the lid member 67, the workability is remarkably deteriorated. If magnets are used to fix the lid member 67, the lid member 67 can be easily attached and detached, but the displacement sensor 55 and the like are adversely affected. Problem arises.
An object of the present invention is to provide a stylus type surface shape measuring instrument that can easily attach and detach a lid member without affecting a displacement sensor or the like.

In order to achieve the above object, a stylus type surface shape measuring instrument according to the present invention includes a displacement sensor probe comprising a differential transformer, a magnetic core of a needle pressure generator, and a fulcrum needle. In the stylus type surface profile measuring instrument, comprising: a support member; and a second support member having a probe, wherein the second support member is attracted to the first support member by magnetic force. A housing case for housing the first support member and the second support member is provided, and the housing case can be attached to the case body from below, and the case body can be attached to the case body from below by surrounding the first support member and the second support member. The lid body is composed of two lid fixing magnets arranged adjacent to each other so that their magnetic poles are opposite to each other, and the side surface of the lid member fixing magnet and Ferromagnetic material so as to surround one end face An adsorbed portion made of a ferromagnetic material is provided at a position of the lid member facing the lid member fixing magnet when the lid member is attached to the case body, and the lid member is attached to the case body. In some cases, the periphery of the lid fixing magnet is surrounded by the peripheral wall of the case body and the attracted portion of the lid member.
The lid member fixing magnet may be, for example, cylindrical.
The peripheral wall surrounding the lid fixing magnet may be formed of a cylindrical side wall that covers the side surface of the magnet and an upper wall on a disk that covers the top surface of the magnet.
Furthermore, the lid fixing magnet and the surrounding wall may be disposed at the lower end of the case body.

In order to achieve the above-described object, the stylus type surface shape measuring instrument according to the present invention arranges two lid member fixing magnets adjacent to each other so that their magnetic poles are opposite to each other in the case body. In addition, a peripheral wall made of a ferromagnetic material is provided so as to surround the side surface and one end surface of the lid member fixing magnet, and at the position facing the lid member fixing magnet when the lid member is attached to the case body, When an adsorbed portion made of a ferromagnetic material is provided and the lid member is mounted on the case body, the periphery of the lid fixing magnet is surrounded by the peripheral wall of the case body and the adsorbed portion of the lid member. Since it comprises, the magnetic field from the magnet for lid fixation becomes very small in the distant position. Therefore, the magnetic field of the lid fixing magnet does not affect the differential transformer of the displacement sensor and the needle pressure generator.
As a result, in a stylus type surface profile measuring instrument that uses a differential transformer as a displacement sensor and performs measurement with a weak force, it uses a magnetic force and does not affect the displacement sensor. The member can be attached and detached, and as a result, the replacement work of the expendable probe is simplified.

It is a schematic internal block diagram which shows an example of the stylus type surface shape measuring device which concerns on this invention. It is the figure which looked at the lid fixing magnet provided in the lower corner | angular part of the case main body 1a from the bottom face of the case main body 1a. It is AA sectional drawing in FIG. It is a top view which shows the to-be-adsorbed plate 25 provided in the corner | angular part of the upper surface of the cover member 1b. It is BB sectional drawing in FIG. It is a figure which shows the state which attached the cover member 1b to the case main body 1a. 2 is a schematic side view of a stylus type surface shape measuring instrument showing an example in which detachable units are arranged at four corners of the bottom of a case 1. FIG. 4 is a schematic bottom view of a stylus type surface shape measuring instrument showing an example in which detachable units are arranged at four corners of the bottom of case 1. FIG. It is a schematic side view which shows the structure of the stylus type surface shape measuring device which used the differential transformer for the displacement sensor. FIG. 10 is a schematic bottom view of the stylus type surface shape measuring instrument shown in FIG. 9.

Embodiments of the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic internal configuration diagram showing an example of a stylus type surface shape measuring instrument according to the present invention.
In the figure, reference numeral 1 denotes a case. The case 1 includes a case main body 1a that is open at the bottom and a lid member 1b that is attached to the lower side of the case main body 1a.
The stylus type surface shape measuring instrument is accommodated in the case 1.
Reference numeral 2 in the drawing denotes a rod-shaped first support member, and the first support member 2 is formed with a holder portion 3 extending downward at an intermediate portion thereof. The holder portion 3 is integrally formed with a fulcrum needle mounting arm 4 extending in the left and right lateral directions. A fulcrum needle 5 is attached to each end of the fulcrum needle mounting arm 4. These two fulcrum needles 5 are supported by two fulcrum receiving portions 6 formed on the case main body 1a, whereby the first support member 1 is placed on the fulcrum receiving member 6 of the case main body 1a via the fulcrum needles 5. And is swingably supported.

At one end of the first support member 2, a measuring element of the displacement sensor 7, that is, a core 8 is attached. The displacement sensor 7 is composed of a differential transformer that generates an electrical signal in accordance with the vertical displacement of the probe, and includes a coil 9.
The other end of the first support member 1 is provided with a core 11 of a needle pressure generator 10 that applies a needle pressure to the probe, and the needle pressure generator 10 includes a coil 12. The core 11 is made of a high magnetic permeability member arranged at a position shifted in the axial direction from the center of the coil 12.

  Further, a longitudinal groove 13 having a trapezoidal cross section is formed in the lower portion of the holder portion 3 of the first support member 1, and both side walls of the longitudinal groove 13 are opened downward in a taber shape. Two magnets 14 are embedded in the bottom portion of the holder portion 3 (specifically, the bottom surface of the longitudinal groove 13) with a gap therebetween. The two magnets 14 embedded in the holder part 3 are arranged so that the polarities are opposite to each other. Specifically, the width of the bottom of the longitudinal groove 13 is about 2 mm, its entrance width is about 4 mm, its depth is about 2 mm, its length is 20 mm, and the two magnets 14 are respectively It consists of a neodymium magnet with a diameter of 1.5 mm and a height of 1.5 mm. The end face of each magnet 14 is positioned 0.1 mm deeper than the bottom face of the longitudinal groove 13 of the holder part 3.

In the drawing, reference numeral 15 denotes a rod-like second support member. The second support member 15 has a probe 16 attached downward at the tip thereof and a high permeability member 17 at the other end. Yes. Guide protrusions 18 extending upward are formed at both ends in the longitudinal direction of the high magnetic permeability member 17, and the opposing side surfaces of the guide protrusions 18 are formed as inclined surfaces that open upward, and form a horizontal plane of each inclined surface. The angle is adjusted to an angle formed by both side walls of the longitudinal groove 13 of the holder part 3 with a horizontal plane. The inclined surfaces of the high permeability member 17 together with the inclined surfaces of both side walls of the longitudinal groove 13 in the holder portion 3 ensure the mutual positioning when attaching the second support member 15 to the first support member 2. Plays the role of
The high permeability member 17 at the other end of the second support member 15 is fitted into the groove 13 of the holder portion 3 of the first support member 2, and the high permeability member 17 is a holder of the second support member 15. The magnetic permeability member 17 is held by the magnet 14 provided in the portion 3, and at that time, the high permeability member 17 contacts the bottom surface of the groove 13 of the holder portion 3, but does not contact the two magnets 14. Yes.

  As described above, the two magnets 14 embedded in the holder portion 3 of the first support member 2 are arranged so that their polarities are reversed, so that the magnetic field created in the place where the magnetic dipole is separated becomes small. The magnetic field in the displacement sensor 7, the needle pressure generator 10 and the sample can be reduced. Further, due to this arrangement, the magnetic lines of force pass through the high permeability member 17 in the second support member 15 below the magnet 14, so that the magnetic field in the sample below and at the probe position is reduced.

  The second support member 15 provided with the probe 16 at one end and the high magnetic permeability member 17 at the other end is a replacement part, and periodically removes the lid member 1b from the case main body 1a to remove the case main body 1a. The lower part is opened, the second support member 15 is removed from the holder part 3 and replaced with a new second support member 15.

The case 1 in the stylus type surface shape measuring instrument configured as described above is configured such that the lid member 1b is fixed to the case main body 1a by a magnetic force.
2 is a view of the lid fixing magnet provided at the lower corner of the case body 1a as viewed from the bottom surface of the case body 1a, and FIG. 3 is a cross-sectional view taken along line AA in FIG.
As shown in the drawing, the lid fixing magnet is composed of two cylindrical magnets 20 and 21 arranged adjacent to each other so that the magnetic poles are opposite to each other. Specifically, these magnets 20 and 21 are made of, for example, a neodymium magnet having a diameter of 1.5 mm and a height of 1.5 mm. In this manner, the magnetic fields at the distant positions are reduced by arranging them adjacent to each other so that the magnetic poles are opposite to each other.
The two cylindrical magnets 20 and 21 are surrounded by a peripheral wall 24 including a cylindrical side wall 22 and a disk-shaped upper wall 23, as shown in FIGS. . The side wall 22 and the upper wall 23 are made of a ferromagnetic material such as SUS430. The disk-shaped upper wall 23 has a diameter of 4 mm and a plate thickness of 0.5 mm, and the cylindrical side wall 22 has an outer dimension of It can be 4 mm in diameter, 3.1 mm in inner diameter and 1.5 mm in height.
The peripheral wall 24 made of the ferromagnetic material is fixed to the case body 1a with an adhesive, and the lid fixing magnets 20 and 21 are fixed to the peripheral wall 24 with an adhesive. The lid fixing magnets 20 and 21 are also fixed by the mutual magnetic force. The lid fixing magnets 20 and 21 and the peripheral wall 24 made of a ferromagnetic material are also fixed to each other by magnetic force.
The material of the case body 1a and the lid 1b is, for example, aluminum.

A disc-shaped attracting plate 25 made of a ferromagnetic material is provided at a corner of the lid member 1a facing the lid fixing magnets 20 and 21 when attached to the case body 1a.
FIG. 4 is a top view showing the suction target plate 25 provided at the corner of the top surface of the lid member 1b, and FIG. 5 shows a cross-sectional view taken along line BB in FIG.
The suction plate 25 is fixed to the upper surface of the lid member 1a with an adhesive. The material of the adsorption plate 25 is, for example, SUS430, and the dimensions thereof can be, for example, a diameter of 6 mm and a plate thickness of 0.5 mm.
The suction plate 25 is attracted to lid fixing magnets 20 and 21 provided on the case body 1a.
FIG. 6 shows a state where the lid member 1b is attached to the case body 1a.
As shown in the drawing, when the lid member 1b is attached to the case main body 1a, the lid fixing magnets 20 and 21 provided on the case main body 1a are formed by the side wall 22, the upper wall 23 and the attracted plate 25 made of a ferromagnetic material. Since the magnetic field lines that are enclosed and exit from the lid fixing magnets 20 and 21 pass through these ferromagnetic materials, the magnetic field outside the ferromagnetic materials is very small.

7 and 8 show a stylus type surface shape measuring instrument showing an example in which the detachable units composed of the lid fixing magnets 20 and 21, the peripheral wall 24, and the attracted plate 25 are arranged at the four corners of the bottom of the case 1. FIG. It is a schematic side view and a schematic bottom view.
The dimensions of the case body 1a are, for example, a length of more than 50 mm, a height of about 20 mm, and a width of less than 30 mm. The lid member 1b covers the entire lower surface and is made of aluminum having a thickness of 1 mm.
The magnetic field at this time was measured. With no components such as a displacement sensor in the case main body 1a, the lid member 1b is attached by the above-mentioned four corner detachable units, and the magnetic field by the magnet is placed at the position of the displacement sensor, force generating mechanism, etc. It was measured. The measurement results include geomagnetism, and as a result of subtracting the evaluation, it was below the measurement limit of 0.1 gauss. The distance between the detachable unit and the displacement sensor is about 10 mm.
Considering that the geomagnetism is 0.45 Gauss (near Tokyo), it can be said that the magnet of the detachable unit has virtually no effect on the displacement sensor.
Therefore, a simple attachment / detachment mechanism of the lid member 1b by magnetic force that does not affect the highly accurate displacement sensor and the weak force generation mechanism can be realized. This simplifies the probe replacement operation.
In use, the sample surface may be 2.5 mm below the lid member 1b, but the magnetic field at that position was 0.5 gauss or less. As a result, it was confirmed that there was no substantial influence on the sample. At the probe tip position, the effect is even smaller because it is about 20 mm away from the detachable unit.

In the embodiment described above, the detachable units are provided at the four corners of the case main body 1a and the lid member 1b. However, the number of detachable units may be reduced to two by reducing the number of parts.
In the embodiment described above, the detachable unit is provided on the bottom surface of the case main body 1a. However, the position where the detachable unit is provided is not limited to the present embodiment, and may be provided on the side surface of the case main body 1a, for example. .
In that case, the side surface may be attached by a magnetic force, and the side surface and the bottom surface of the case 1 may be covered with an L-shaped plate.
Similarly, the detachable unit may be arranged on the upper surface of the case body 1a. In that case, the upper surface may be attached by magnetic force, and the upper surface, side surface, and bottom surface of the case 1 may be covered with a U-shaped plate.

DESCRIPTION OF SYMBOLS 1 Case 1a Case main body 1b Cover member 2 First support member 3 Holder part 4 Needle mounting arm for fulcrum 5 Needle for fulcrum 6 Support point receiving part 7 Displacement sensor 8 Core (displacement sensor measuring element)
9 Coil 10 Needle pressure generator 11 Core (Core of needle pressure generator)
12 Coil 13 Longitudinal groove 14 Magnet 15 Second support member 16 Probe 17 High permeability member 18 Guide protrusion

20 Magnet (Magnet for fixing the lid)
21 Magnet (Magnet for fixing the lid)
22 Side wall 23 Upper wall 24 Peripheral wall 25 Adsorbed plate

DESCRIPTION OF SYMBOLS 51 1st support member 52 Needle attachment member for fulcrum 53 Needle for fulcrum 54 Support point receiving member 55 Displacement sensor 56 Core 57 Coil 58 Needle pressure generator 59 Core 60 Coil 61 Magnet 62 Second support member 63 Probe 64 High permeability member 65 Case 66 Upper case body 67 Cover member

Claims (4)

A second support member having a probe for a displacement sensor comprising a differential transformer, a magnetic core of a needle pressure generator, and a fulcrum needle; and a second support member having a probe; In the stylus type surface shape measuring instrument configured such that the member is attracted to the first support member by magnetic force,
Providing a housing case for housing the first support member and the second support member;
The housing case is composed of a case body that is open at a lower part surrounding the first support member and the second support member, and a lid member that is configured to be detachable from the case body from below,
Two lid fixing magnets are arranged adjacent to the case main body so that their magnetic poles are opposite to each other, and a ferromagnetic material is provided so as to surround a side surface and one end surface of the lid member fixing magnet. A surrounding wall consisting of
In the lid member, at the position facing the lid member fixing magnet when mounted on the case body, an attracted portion made of a ferromagnetic material is provided,
A stylus type surface shape measurement characterized in that when the lid member is attached to the case body, the circumference of the lid fixing magnet is surrounded by the surrounding wall of the case body and the attracted portion of the lid member. vessel. The stylus type surface shape measuring instrument, wherein the lid fixing magnet is cylindrical. The stylus type according to claim 2, wherein the surrounding wall surrounding the lid fixing magnet comprises a cylindrical side wall covering a side surface of the magnet and an upper wall on a disk covering the upper surface of the magnet. Surface shape measuring instrument. The stylus type surface shape measuring instrument according to any one of claims 1 to 3, wherein the lid fixing magnet and the surrounding wall are disposed at a lower end of the case body.

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