JP2015169561A - Contact type displacement gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact type displacement gauge in which an air supply allows a contact probe to move, and which can be downsized in a direction orthogonal to a movement direction of a contact probe.SOLUTION: A measurement head 100H and a control unit 60 are configured to be connected by a cable 90, and in the measurement head 100H, a light projector 30, a scale 50 and a light reception unit 40 are configured to be provided in an enclosure 10 so as to be lined up in a direction crossing one direction, and a contact probe 20 is configured to be supported in the enclosure 10 movably in one direction. The scale 50 is configured to be irradiated with non-collimated light by the light projector 30, and the non-collimated light passing through a plurality of slits of the scale 50 is configured to be received by the light reception unit 40. An output signal of the light reception unit 40 is configured to be transmitted to the control unit 60 by a signal line of the cable 90. Air supplied by an air supply unit 86 is configured to be guided in the enclosure 10 through a passage of the cable 90, and thereby the scale 50 is configured to move in one direction together with the contact probe 20. When measuring, an output signal before and after the movement of the contact probe 20 is configured to be processed by the control unit 60.

Description

  The present invention relates to a contact displacement meter using a contact.

  The contact-type displacement meter has a contact that is in contact with the surface of the object and is linearly movable in one direction (see, for example, Patent Documents 1 and 2).

  The contact displacement meter of Patent Document 1 includes a light emitting element, a line sensor, and a moving scale. The moving scale is connected to the contact. A predetermined pattern is arranged on the moving scale along the direction in which the contact can move. The light emitted from the light emitting element passes through the collimator lens to become substantially parallel light, passes through the moving scale, and is irradiated to the line sensor. The displacement of the contact is calculated based on the light reception signal read by the line sensor.

  The contact-type sensor head of Patent Document 2 includes a cylinder and a guide rod. The guide rod is disposed in the cylinder. A contact and a piston are attached to one end and the other end of the guide lot, respectively. A voltage is applied between the contact and the workpiece. When air is supplied into the cylinder, the piston moves in the cylinder, and the contact moves in one direction. When the contact comes into contact with the workpiece, a closed circuit including the contact and the workpiece is formed. The position of the workpiece is calculated by detecting the current flowing through the closed circuit.

JP 2009-236498 A JP-A-8-193826

  There is a case where a contact displacement meter that can move a contact by supplying air as in Patent Document 2 is desired. However, in the contact type sensor head of Patent Document 2, the position of the insulating work cannot be calculated. On the other hand, in the contact displacement meter of Patent Document 1, it is necessary to provide a light emitting element, a line sensor, a moving scale, a collimator lens, and wiring. For this reason, when the air supply method as in Patent Document 2 is applied to the contact displacement meter of Patent Document 1, it is difficult to reduce the size of the contact displacement meter.

  An object of the present invention is to provide a contact displacement meter that can move a contact by supplying air and that can be downsized in a direction orthogonal to the moving direction of the contact.

  (1) A contact displacement meter according to the present invention includes a measuring unit, a processing unit that processes an output signal of the measuring unit, a first cable connected between the measuring unit and the processing unit, and a first An air supply unit that supplies air to the cable, and the measurement unit includes a housing, a contact supported by the housing so as to be movable in one direction, and a plurality of light-transmissive portions arranged in one direction, A scale configured to be movable in one direction together with the contact; a light projecting unit that irradiates the scale with non-parallel light; and a light receiving unit that receives the non-parallel light transmitted through the plurality of light-transmitting parts of the scale; The light projecting unit, the scale, and the light receiving unit are provided in the housing so as to be arranged in a direction intersecting with one direction, and the first cable includes a first signal line that transmits an output signal of the light receiving unit to the processing unit, A passage for guiding the air supplied by the air supply unit into the housing so that the contact moves in the protruding direction. Including the.

  In this contact displacement meter, the measurement unit and the processing unit are connected by a first cable. Air is supplied to the first cable by the air supply unit. In the measurement unit, the light projecting unit, the scale, and the light receiving unit are provided in the housing so as to be aligned in a direction intersecting with one direction. The contact is supported by the housing so as to be movable in one direction. Non-parallel light is irradiated onto the scale by the light projecting unit. Non-parallel light transmitted through the plurality of light transmitting portions of the scale is received by the light receiving portion.

  The output signal of the light receiving unit is transmitted to the processing unit through the first signal line of the first cable. Moreover, the air supplied by the air supply unit is guided into the housing through the passage of the first cable. Thereby, it moves to the direction where a contact child projects. As a result, the contact is set to the initial position before measurement together with the scale. At the time of measurement, the scale moves in one direction together with the contact, and the output signal before and after the contact is moved is processed by the processing unit.

  According to this configuration, since air is supplied into the housing through the passage of the first cable, there is no need to separately provide an air supply portion for supplying air into the housing. Further, it is not necessary to provide an optical element such as a collimator lens for collimating light between the light projecting unit and the scale. This makes it possible to reduce the size of the contact displacement meter in a direction orthogonal to the moving direction of the contact while allowing the contact to move by supplying air.

  (2) The contact-type displacement meter includes a relay unit connected to the first cable, a display unit that displays a processing result of the processing unit, and a second cable connected between the relay unit and the display unit. The air supply unit may be provided in the relay unit.

  In this case, the relay unit is connected to the first cable, and the relay unit and the display unit are connected by the second cable. As a result, the processing result of the processing unit is displayed on the display unit. Here, the air supply unit is provided in the relay unit. Since the air supply part is not provided in the first cable, the handleability of the first cable is improved.

  (3) The processing unit may be provided in the relay unit.

  In this case, it is not necessary to provide another arrangement area for arranging the processing unit. Thereby, a contact-type displacement meter can be made compact. In addition, since the air supply unit is provided in the relay unit, the processing unit can be cooled by the air supplied from the air supply unit.

  (4) The measurement unit further includes at least one light emitting unit provided in the housing, and the processing unit controls the light emission operation of the at least one light emitting unit based on the processing result of the output signal of the light receiving unit, and receives the light. The first cable further includes a second signal line for transmitting the control signal generated by the processing unit to at least one light emitting unit and the light receiving unit of the measurement unit. But you can.

  In this case, the user can recognize the processing result of the output signal by observing the light emitting operation of at least one light emitting unit. The second signal line of the first cable is commonly used to transmit a control signal to at least one light emitting unit and light receiving unit. Therefore, it is not necessary to separately provide signal lines for transmitting control signals to at least one light emitting unit and light receiving unit. Thereby, a 1st cable can be reduced in diameter and weight.

  (5) The at least one light emitting unit may include a plurality of light emitting units that operate at different voltages, and the processing unit may control the light emitting operations of the plurality of light emitting units by changing the voltage of the control signal. .

  In this case, the light emission operations of the plurality of light emitting units can be controlled using the common second signal line. Thereby, a several light emission part can be provided in a measurement part, without preventing the diameter reduction and weight reduction of a 1st cable. As a result, the user can easily recognize a plurality of processing results of the output signal by observing the light emission operations of the plurality of light emitting units.

  (6) Each of the plurality of light emitting units is a light emitting diode, and the forward voltages of the plurality of light emitting units may be different from each other.

  In this case, the light emitting operations of the plurality of light emitting units can be controlled with a simple circuit using the common second signal line.

  (7) The contact-type displacement meter further includes a fixing member configured to be able to fix the measurement unit at a desired fixing position, the housing is formed to extend in one direction, and the fixing member intersects the one direction. A main body member formed to extend in the other direction and having an end surface and a pair of side surfaces facing each other; and a holding member that holds the housing of the measurement unit on the main body member, the main body member penetrating in one direction and An insertion hole into which the housing is inserted and a first through hole that penetrates from the end surface to the insertion hole, and is held via the first through hole of the main body member in a state in which the housing is inserted into the insertion hole. The housing may be pressed by the member.

  In this case, the housing of the measurement unit is inserted into the insertion hole of the main body member. In this state, the housing is pressed by the holding member through the first through hole of the main body member. Thereby, a housing | casing is hold | maintained at a main body member. By fixing the main body member at a desired fixing position, the measurement unit is fixed at the desired fixing position.

  According to this configuration, the first through hole is provided in the end surface of the main body member extending in the other direction. By operating the holding member from the other direction, the housing can be held by the main body member. Therefore, there is no need to operate the holding member from the side surface of the main body member. Thereby, even when a plurality of fixing members are arranged so that the side surfaces of the main body member are close to each other, the measuring unit can be attached to and detached from the desired fixing member without being interfered by other fixing members. As a result, it is possible to easily fix the plurality of measurement units close to each other at a desired fixing position with high density.

  (8) The holding member includes a pressing member inserted into the insertion hole and a first screw member inserted into the first through hole, and the insertion hole is in a state where the housing and the pressing member are arranged in the other direction. The first screw member inserted into the first through-hole presses the pressing member, and the pressing member presses the casing. The body may be held by the body member.

  In this case, the housing and the pressing member are inserted into the first through hole in a state where they are aligned in the other direction. In this state, the pressing member is pressed by the first screw member, and the housing is pressed by the pressing member. Thereby, a housing | casing can be hold | maintained to a main body member with a simple structure.

  (9) The pressing member may be provided so as to be swingable in the other direction within the insertion hole. In this case, since the operation of inserting the pressing member into the insertion hole is not required, the operation of attaching the measurement unit to the fixing member is facilitated.

  (10) The main body member further includes a second through hole penetrating in one direction, and the second through hole is provided so as to be aligned with the insertion hole in the other direction, and is inserted into the second through hole. The main body member may be fixed at a fixed position by the second screw member.

  In this case, the main body member can be easily fixed at the fixed position by the second screw member. In addition, since the second through hole is provided so as to be aligned with the insertion hole in the other direction, the fixing member is prevented from being enlarged in the lateral direction. Thereby, a plurality of measuring heads can be arranged close to each other.

  It is possible to reduce the size of the contact-type displacement meter in a direction orthogonal to the moving direction of the contact while allowing the contact to move by supplying air.

It is a block diagram which shows the structure of the contact-type displacement meter which concerns on one embodiment of this invention. It is a figure which shows the measuring head of the contact-type displacement meter of FIG. It is a disassembled perspective view of a relay part. It is a longitudinal cross-sectional view of a relay part. It is a figure which shows the comparison with the contact-type displacement meter which concerns on one embodiment of this invention, and the contact-type displacement meter which concerns on 1st reference form. It is a schematic diagram which shows the electrical connection of a relay part and a measurement head. It is a figure which shows the level of the control signal in each part of a signal line It is a figure which shows the relationship between the range of the "H" level of the control signal of FIG.7 (b), and the light emission state of a light emission part. It is a schematic diagram which shows the electrical connection of the relay part and measurement head in a 2nd reference form. It is a perspective view which shows a fixing member. It is a perspective view which shows the measuring head fixed by the fixing member of FIG. FIG. 11 is a perspective view showing a plurality of measurement heads fixed by a plurality of fixing members of FIG. 10, respectively. It is a horizontal sectional view of the fixing member in the 3rd reference form. FIG. 14 is a horizontal sectional view showing a plurality of measurement heads fixed by a plurality of fixing members of FIG. 13, respectively. It is a figure which shows an example of arrangement | positioning of a slit. The received light amount distribution represented by the received light data and an enlarged view thereof are shown. It is a schematic diagram which shows the relationship between a light projection part, a scale, and a light-receiving part. It is a schematic diagram showing a plurality of peak positions in the received light amount distribution within the range D of the light receiving surface. It is a figure for demonstrating the calculation procedure of the absolute position of a slit.

(1) Configuration of Contact Displacement Meter FIG. 1 is a block diagram showing a configuration of a contact displacement meter according to the first embodiment of the present invention. FIG. 2 is a diagram showing a measuring head of the contact displacement meter of FIG. FIG. 2 (a) shows the configuration inside the housing, and FIG. 2 (b) shows an enlarged view of part A of FIG. 2 (a). Hereinafter, a contact displacement meter 100 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the contact displacement meter 100 includes a housing 10, a contact 20, a light projecting unit 30, a light receiving unit 40, a scale 50, a control unit 60, a display unit 70, a relay unit 80, and cables 1, 90. including. The housing 10, the contact 20, the light projecting unit 30, the light receiving unit 40 and the scale 50 constitute a measuring head 100 </ b> H.

  The measuring head 100H is connected to the relay unit 80 via the cable 90. The relay unit 80 is provided with an air supply unit 86 for supplying air into the housing 10 of the measurement head 100H. The cable 90 includes six signal lines 91 to 96 (FIG. 6 to be described later) and a passage 97 (FIG. 4 to be described later) for guiding air into the housing 10. Details will be described later. The relay unit 80 is connected to the display unit 70 via the cable 1.

  In this example, the control unit 60 is provided in the relay unit 80. In this case, since the control unit 60 does not need to be provided in the housing 10, the housing 10 can be downsized. Further, there is no need to provide another arrangement area for arranging the control unit 60. Thereby, the contact-type displacement meter 100 can be reduced in size. Furthermore, since the air supply unit 86 is provided in the relay unit 80, the control unit 60 can be cooled by the air supplied by the air supply unit 86.

  In the measurement head 100 </ b> H, the light projecting unit 30, the light receiving unit 40, and the scale 50 are accommodated in the housing 10. Further, as shown in FIGS. 2A and 2B, the housing 10 houses a shaft 11, a spring 12, a scale holding unit 13, and an optical system holding unit 14.

  In this example, the housing 10 has an outer diameter that is substantially the same as the contact 20. Therefore, the contact displacement meter 100 has an elongated shape as a whole. Thereby, the displacement of the measurement object can be measured through a narrow space. In addition, the contact displacement meter 100 can be easily stored and carried.

  The optical system holding unit 14 is provided with two light emitting units 15 and 16 for simply displaying the measurement result of the contact displacement meter 100. In the present embodiment, the light emitting unit 15 is a green LED (light emitting diode), and the light emitting unit 16 is a red LED. When the dimension of the measurement object measured by the contact displacement meter 100 is within a predetermined range, the light emitting unit 15 emits green light. On the other hand, when the dimension of the measurement object measured by the contact displacement meter 100 exceeds a predetermined range, the light emitting unit 16 emits red light. A window portion 17 for transmitting light emitted by the light emitting portions 15 and 16 is formed on the side surface of the housing 10.

  The contact 20 is attached to one end of the shaft 11 so as to be movable in one direction with respect to the housing 10. Hereinafter, one direction is referred to as the X direction. The shaft 11 includes a ball bearing. Further, the scale holding unit 13 is attached to the other end of the shaft 11 via the spring 12. The scale 50 is made of a long plate member and is held by the scale holding unit 13. The scale 50 is made of, for example, glass.

  Air is supplied into the housing 10 from the relay section 80 in FIG. 1 through a passage 97 (FIG. 4 described later) of the cable 90. Due to the pressure of the supplied air, the shaft 11, the contact 20 and the scale 50 move in the X direction integrally with the housing 10.

  As shown in FIG. 2B, the optical system holding unit 14 has two support pieces 14 a and 14 b extending in parallel toward the contact 20. The light projecting unit 30 and the electric circuit 31 are attached to the inner surface of the one support piece 14 a of the optical system holding unit 14. The electric circuit 31 supplies power to the light projecting unit 30. On the other hand, the light receiving unit 40 is attached to the inner surface of the other support piece 14 b of the optical system holding unit 14 via the circuit board 41. A scale 50 is disposed between the two support pieces 14 a and 14 b of the optical system holding unit 14.

  In this state, the shaft 11, the spring 12, the scale holding unit 13, and the optical system holding unit 14 are accommodated in the housing 10. Accordingly, the light projecting unit 30 and the light receiving unit 40 face each other with the scale 50 interposed therebetween in the housing 10. Further, the two light emitting units 15 and 16 of the optical system holding unit 14 overlap with the window unit 17 of the housing 10. The scale 50 is disposed so as to be substantially orthogonal to the optical axis of the light projecting unit 30. The scale 50 has a plurality of slits. A unique number is assigned to each slit. The arrangement of the plurality of slits of the scale 50 will be described later.

  The light projecting unit 30 is, for example, an LED. The light projecting unit 30 may be another light emitting element such as an LD (laser diode). The light projecting unit 30 is not provided with an optical element such as a collimator lens for collimating light. Accordingly, the light emitted from the light projecting unit 30 is received by the light receiving unit 40 through a part of the slits of the scale 50 while spreading at a predetermined angle.

  The light receiving unit 40 is a line sensor having a plurality of light receiving elements arranged in the X direction. A plurality of light receiving elements constitute a plurality of pixels. In this example, each light receiving element is a CMOS (complementary metal oxide semiconductor). Each light receiving element may be another element such as a CCD (charge coupled device).

  The light receiving unit 40 has a light receiving surface including a plurality of pixels arranged in the X direction. The light receiving surface of the light receiving unit 40 is disposed so as to be substantially orthogonal to the optical axis of the light projecting unit 30. From the light receiving unit 40, an analog electric signal (hereinafter referred to as a light receiving signal) indicating the distribution of received light amount on the light receiving surface is transmitted to the control unit 60 provided in the relay unit 80 through the circuit board 41 and the cable 90 in FIG. Is output.

  As shown in FIG. 1, the control unit 60 includes a CPU (central processing unit) 61, a memory 62, an A / D (analog / digital) converter 63, and a D / A (digital / analog) converter 64. The light receiving signal output from the light receiving unit 40 is sampled by the A / D converter 63 at a constant sampling period and converted into a digital signal.

  The digital signal output from the A / D converter 63 is sequentially stored in the memory 62 as received light data indicating the received light amount distribution. The memory 62 stores a displacement calculation program for calculating the displacement of the contact 20.

  The received light data stored in the memory 62 is given to the CPU 61. The CPU 61 executes a displacement calculation program for the contact 20 based on the light reception data given by the memory 62. Thereby, the displacement calculation process for calculating the displacement of the contact 20 is executed. The display unit 70 is configured by, for example, a 7-segment display. The display unit 70 may be configured by a dot matrix display. The CPU 61 causes the display unit 70 to display the displacement of the contact 20 calculated by the displacement calculation process through the cable 1.

  The CPU 61 controls operations of the light emitting units 15 and 16, the light projecting unit 30, and the light receiving unit 40. Control signals for controlling the operations of the light emitting units 15 and 16, the light projecting unit 30 and the light receiving unit 40 are converted into analog signals by the D / A converter 64, and the light emitting units 15 and 16, the light projecting unit 30 and the light receiving unit are received. Given to part 40.

  In this example, one set of the measurement head 100 </ b> H is configured by the set of the housing 10, the contact 20, the light projecting unit 30, the light receiving unit 40, and the scale 50. A plurality of measuring heads 100H can be connected to one display unit 70 using a plurality of sets of cables 1 and 90 and the relay unit 80, respectively. According to this configuration, the thicknesses of the plurality of portions of the measurement target can be simultaneously measured by bringing the plurality of contacts 20 of the plurality of measurement heads 100H into contact with the plurality of portions of the measurement target, respectively. Further, based on the measurement values obtained by the plurality of measurement heads 100H, the maximum value, the minimum value, the average value, the flatness, or the like of the thickness of the measurement object can be obtained as the evaluation value.

  Data indicating the measurement value or the evaluation value is stored in the memory 62. Further, the CPU 61 can give data to the outside through an interface (not shown). In this example, the CPU 61 can give a BCD (Binary Corded Decimal) output to an external programmable controller. The CPU 61 can perform serial communication with an external personal computer or programmable controller in accordance with the RS-232C standard.

(2) Relay Unit FIG. 3 is an exploded perspective view of the relay unit 80. FIG. 4 is a longitudinal sectional view of the relay unit 80. As shown in FIGS. 3 and 4, the relay unit 80 includes a housing unit 81, a lid body 83, and an air supply unit 86.

  The casing 81 has a bottom surface and four side surfaces, and has a substantially rectangular opening 81a at the top. A circular opening 81 b is formed on one side surface of the housing 81. A connection portion 82 for connecting the cable 90 is formed on the bottom surface portion of the housing portion 81.

  A circuit board 84 on which the control unit 60 of FIG. 1 is mounted is provided on the lid 83, and a connection unit 85 to which the cable 1 of FIG. 1 is connected is formed. In the example of FIGS. 3 and 4, two circuit boards 84 are provided on the lid portion 83. The lid 83 is attached to the housing 81 so as to close the opening 81a of the housing 81.

  By attaching the lid 83 to the housing 81, the circuit board 84 and the controller 60 are accommodated in the housing 81. The cable 90 is connected to the control unit 60 in the housing unit 81 through the connection unit 82, and the cable 1 is connected to the control unit 60 in the housing unit 81 through the connection unit 85.

  The air supply unit 86 includes a closing member 86a and a supply port 86b. The supply port 86b is formed in the closing member 86a. The closing member 86a is attached to one side surface portion of the housing portion 81 so as to close the opening 81b of the housing portion 81 via a seal member. As shown in FIG. 4, the closing member 86a is formed with a vent hole 86h that guides air from the supply port 86b to the opening 81b.

  In FIG. 4, as indicated by an arrow, the air that has flowed into the closing member 86a from the supply port 86b of the air supply portion 86 passes through the vent hole 86h of the closing member 86a and the opening 81b of the casing portion 81. 81 is led into the interior. Air in the casing 81 is supplied to the measurement head 100H of FIG. 1 through a passage 97 in the cable 90 connected to the connecting portion 82. The contact 20 of FIG. 1 moves by the pressure of the supplied air.

(3) First Reference Embodiment FIG. 5 is a diagram showing a comparison between a contact displacement meter 100 according to an embodiment of the present invention and a contact displacement meter 100A according to a first reference embodiment. FIG. 5A shows a side view of the contact displacement meter 100 according to the present embodiment, and FIG. 5B shows a side view of the contact displacement meter 100A according to the first reference embodiment.

  As shown in FIG. 5A, in the contact displacement meter 100 according to the present embodiment, air is supplied into the housing 10 through the cable 90. Therefore, there is no need to provide the housing 10 with an air supply unit for supplying air into the housing 10. According to this configuration, the housing 10 can be reduced in size in a direction orthogonal to the moving direction of the contact 20. Thereby, the housing | casing 10 can be made into the substantially same outer diameter as the contactor 20. FIG. As a result, the contact displacement meter 100 can be elongated.

  On the other hand, as shown in FIG. 5B, in the contact displacement meter 100A according to the first reference embodiment, an air supply portion 86A is provided at the upper end of the side portion of the housing 10A. Air is not supplied into the housing 10A through the cable 90A, but air is supplied into the housing 10A from the supply port 86B of the air supply unit 86A. According to this configuration, the housing 10A is enlarged in a direction orthogonal to the moving direction of the contact 20A.

(4) Electrical Connection between Relay Unit and Measuring Head FIG. 6 is a schematic diagram showing electrical connection between the relay unit 80 and the measuring head 100H. As shown in FIG. 6, the relay unit 80 and the measurement head 100 </ b> H are connected by a cable 90. The cable 90 includes six signal lines 91, 92, 93, 94, 95, and 96. The signal line 91 connects the ground terminal held at the ground potential Vg of the relay unit 80 and the ground terminal held at the ground potential Vg of the measuring head 100H. The signal line 92 connects the power supply terminal held at the power supply potential Vs of the relay unit 80 and the power supply terminal held at the power supply potential Vs of the measuring head 100H.

  The signal line 93 connects the CPU 61 of the control unit 60 of the relay unit 80 and the anode A of the light projecting unit 30. The signal line 93 is inserted with a protective resistor R1. The cathode K of the light projecting unit 30 is held at the ground potential Vg. A control signal for controlling the operation of the light projecting unit 30 is given from the CPU 61 to the light projecting unit 30 through the signal line 93.

  The signal line 94 connects the A / D converter 63 of the control unit 60 and the light receiving unit 40. A light reception signal from the light receiving unit 40 is given to the A / D converter 63 through the signal line 94. The signal line 95 connects the CPU 61 of the control unit 60 and the light receiving unit 40. A clock pulse from the CPU 61 is given to the light receiving unit 40 through the signal line 95.

  A buffer circuit B1 is disposed in the relay unit 80, and a buffer circuit B2 is disposed in the measurement head 100H. The CPU 61 is connected to the input terminal of the buffer circuit B1. The output terminal of the buffer circuit B1 is connected to the input terminal of the buffer circuit B2 through the signal line 96. The output terminal of the buffer circuit B2 is connected to the light receiving unit 40.

  The measurement head 100H is provided with two comparators C1 and C2. The signal line 96 is connected to the inverting input terminal of the comparator C1 and the inverting input terminal of the comparator C2. The non-inverting input terminal of the comparator C1 is held at the reference potential Vr1, and the non-inverting input terminal of the comparator C2 is held at the reference potential Vr2.

  The output terminal of the comparator C1 is connected to the cathode K of the light emitting unit 15, and the output terminal of the comparator C2 is connected to the cathode K of the light emitting unit 16. A resistor R3 is interposed between the output terminal of the comparator C2 and the cathode K of the light emitting unit 16. The anode A of the light emitting unit 15 and the anode A of the light emitting unit 16 are connected to the power supply terminal through the protective resistor R2.

  A control signal for controlling the operations of the light receiving unit 40 and the two light emitting units 15 and 16 is supplied from the CPU 61 to the light receiving unit 40 and the two comparators C1 and C2 through the signal line 96.

  In the example of FIG. 6, the magnitude of the control signal output from the buffer circuit B1 is controlled by the D / A converter 64 of the control unit 60 in a range higher than the ground potential Vg and lower than the reference potential Vr0. Here, the reference potential Vr0 is lower than the power supply potential Vs. The reference potential Vr1 is set to be higher than the reference potential Vr2 and lower than the reference potential Vr0. The reference potential Vr2 is set to be equal to or higher than the ground potential Vg and lower than the reference potential Vr1.

(5) Control of Light Receiving Unit and Light Emitting Unit FIG. 7 is a diagram showing the level of the control signal in each part of the signal line 96. The CPU 61 generates a control signal shown in FIG. As shown in FIG. 7A, the control signal periodically changes to the “H” level and the “L” level. One cycle of the control signal is T. The control signal is held at the “L” level during the period t of the period T and is held at the “H” level during the other periods. In the present embodiment, the period T is 4 ms, for example, and the period t is 10 μs, for example. In the example of FIG. 7A, the “H” level and the “L” level are the power supply potential Vs and the ground potential Vg, respectively.

  The control signal in FIG. 7A is applied to the input terminal of the buffer circuit B1 in FIG. The buffer circuit B1 generates the control signal in FIG. 7B from the control signal in FIG. The “H” level of the control signal generated by the buffer circuit B1 is controlled between the ground potential Vg and the reference potential Vr0 lower than the power supply potential Vs by the D / A converter 64 of FIG.

  The control signal in FIG. 7B is applied to the input terminal of the buffer circuit B2 in FIG. 6, and is also applied to the inverting input terminal of the comparator C1 in FIG. 6 and the inverting input terminal in the comparator C2 in FIG. The buffer circuit B2 generates the control signal in FIG. 7C from the control signal in FIG. The “H” level of the control signal generated by the buffer circuit B2 is held at the power supply potential Vs. Therefore, the control signal in FIG. 7C is equal to the control signal in FIG.

  The control signal in FIG. 7C functions as a start pulse for the light receiving unit 40. The control signal in FIG. 7C is given to the light receiving unit 40. Thereby, the operation of the light receiving unit 40 is controlled.

  7B is applied to the non-inverting input terminal of the comparator C1 and the non-inverting input terminal of the comparator C2, the light emission and quenching of the two light emitting units 15 and 16 in FIG. 6 are controlled. . FIG. 8 is a diagram showing the relationship between the “H” level range of the control signal in FIG. 7B and the light emission states of the light emitting units 15 and 16.

  As shown in FIG. 8, when the “H” level of the control signal is higher than the ground potential Vg and equal to or lower than the reference potential Vr2, the potential of the output terminal of the comparator C1 and the potential of the output terminal of the comparator C2 are “ It is held at the H ”level. In this case, no voltage higher than the forward voltage is applied to the light emitting units 15 and 16. As a result, the light emitting units 15 and 16 are turned off.

  When the “H” level of the control signal is higher than the reference potential Vr2 and lower than the reference potential Vr1, the potential of the output terminal of the comparator C1 is held at the “H” level, and the potential of the output terminal of the comparator C2 is It is held at “L” level. In this case, no voltage higher than the forward voltage is applied to the light emitting unit 15, but a voltage higher than the forward voltage is applied to the light emitting unit 16. Thereby, the light emission part 15 will be in a quenching state, and the light emission part 16 will be in a light emission state.

  When the “H” level of the control signal is higher than the reference potential Vr1 and equal to or lower than the reference potential Vr0, the potential of the output terminal and the potential of the output terminal of the comparator C1 are held at the “L” level. Here, as a characteristic of the light emitting units 15 and 16, the forward voltage of the light emitting unit 15 is lower than the forward voltage of the light emitting unit 16. In this case, since a voltage equal to or higher than the forward voltage is applied to the light emitting unit 15, a forward current flows through the light emitting unit 15, and the light emitting unit 15 enters a light emitting state. On the other hand, almost no current flows through the light emitting unit 16, and the light emitting unit 16 is in a quenching state.

  The D / A converter 64 in FIG. 6 sets the “H” level of the control signal in FIG. 7B to the ground potential Vg when the dimension of the measurement object is not measured by the contact displacement meter 100. It is controlled to be higher than the reference potential Vr2. When the dimension of the measurement object measured by the contact displacement meter 100 exceeds a predetermined range, the D / A converter 64 sets the “H” level of the control signal in FIG. It is controlled to be higher than Vr2 and lower than the reference potential Vr1. The D / A converter 64 sets the “H” level of the control signal higher than the reference potential Vr1 when the dimension of the measurement object measured by the contact displacement meter 100 is within a predetermined range. The potential is controlled to be lower than Vr0.

  According to this control, when the dimension of the measuring object is not measured by the contact displacement meter 100, the light emitting units 15 and 16 do not emit light. When the dimension of the measurement object measured by the contact displacement meter 100 exceeds a predetermined range, only the light emitting unit 16 emits red light. When the dimension of the measurement object measured by the contact displacement meter 100 is within a predetermined range, only the light emitting unit 15 emits green light.

  The user can recognize the measurement result by observing the light emitting operation of the two light emitting units 15 and 16. In addition, since the forward voltages of the two light emitting units 15 and 16 are different from each other, the light emitting operations of the plurality of light emitting units 15 and 16 can be controlled using a common signal line 96 with a simple circuit configuration.

  During the period t in FIG. 7B, since the control signal is held at the “L” level, the light emitting units 15 and 16 are in the extinction state. However, since the period t is extremely short, the user cannot recognize the quenching of the light emitting units 15 and 16, and no problem in use occurs.

  According to the above connection, a control signal for controlling the two light emitting units 15 and 16 and the light receiving unit 40 can be transmitted using the common signal line 96. Therefore, it is not necessary to separately provide a signal line for transmitting the control signal for controlling the two light emitting units 15 and 16 and the control signal for controlling the light receiving unit 40 in the cable 90. Thereby, the cable 90 can be reduced in diameter and weight.

(6) Second Reference Embodiment FIG. 9 is a schematic diagram showing electrical connection between the relay unit and the measurement head in the second reference embodiment. As shown in FIG. 9, in the contact displacement meter according to the second reference embodiment, the relay portion 80A and the measurement head 100HA are connected by a cable 90B. The relay unit 80A has the same configuration as the relay unit 80 of FIG. 6 except that the relay unit 80A does not have the buffer circuit B1.

  The measurement head 100HA has the same configuration as the measurement head 100H of FIG. 6 except for the following points. The measuring head 100HA does not have the buffer circuit B2, the comparators C1 and C2, and the resistor R3. The measurement head 100HA includes protective resistors R2A and R3A instead of the protective resistor R2. The cable 90B includes eight signal lines 91, 92, 93, 94, 95, 96A, 96B, and 96C.

  The signal line 96 </ b> A connects the CPU 61 of the control unit 60 and the light receiving unit 40. A control signal for controlling the operation of the light receiving unit 40 is given from the CPU 61 to the light receiving unit 40 through the signal line 96A.

  The signal line 96 </ b> B connects the CPU 61 of the control unit 60 and the anode A of one light emitting unit 15. A protective resistor R2A is inserted in the signal line 96B. The cathode K of the light emitting unit 15 is held at the ground potential Vg. A control signal for controlling the operation of the light emitting unit 15 is given from the CPU 61 to the light emitting unit 15 through the signal line 96B.

  The signal line 96 </ b> C connects the CPU 61 of the control unit 60 and the anode A of the other light emitting unit 16. A protective resistor R3A is inserted in the signal line 96C. The cathode K of the light emitting unit 16 is held at the ground potential Vg. A control signal for controlling the operation of the light emitting unit 16 is given from the CPU 61 to the light emitting unit 16 through the signal line 96C.

  According to the above connection, the signal lines 96A to 96C for supplying control signals to the two light emitting units 15 and 16 and the light receiving unit 40 are separately provided in the cable 90B. Therefore, the cable 90B is increased in size and weight.

(7) Fixing member The contact-type displacement meter 100 further includes a fixing member for fixing the measuring head 100H in the vicinity of the measurement object. FIG. 10 is a perspective view showing the fixing member. FIG. 11 is a perspective view showing the measurement head 100H fixed by the fixing member of FIG. FIG. 10A shows an exploded perspective view of the fixing member, and FIG. 10B shows a perspective view of the fixing member after assembly. FIGS. 11A and 11B are perspective views of the measurement head 100H as viewed obliquely from above and obliquely below, respectively.

  As shown in FIGS. 10A and 10B, the fixing member 110 includes a main body member 111, a pressing member 112, and a plurality (three in this example) of fixing screws 113a, 113b, and 113c. The main body member 111 has a substantially rectangular parallelepiped shape extending in the Y direction. Here, the Y direction is a direction orthogonal to the X direction in FIG. The main body member 111 has a front surface 111A, a back surface 111B, one side surface 111C, another side surface 111D, an upper surface 111E, and a bottom surface 111F.

  The main body member 111 is formed with a substantially rectangular insertion hole 111h penetrating from the upper surface 111E to the bottom surface 111F. The measurement head 100H of FIG. 1 is inserted into the insertion hole 111h, and the pressing member 112 is disposed. The inner peripheral surface of one end of the insertion hole 111h is curved so as to be in contact with the outer peripheral surface of the measuring head 100H in FIG.

  The main body member 111 is formed with a screw hole 111a that penetrates from the one side surface 111C to the other side surface 111D through the insertion hole 111h. The main body member 111 is formed with a screw hole 111b penetrating from the front surface 111A to the insertion hole 111h. Furthermore, the main body member 111 is formed with a circular through hole 111c that penetrates from the upper surface 111E to the bottom surface 111F. The through hole 111c is provided so as to be aligned with the insertion hole 111h in the Y direction.

  The pressing member 112 has a plate shape, and one surface of the pressing member 112 is curved so as to be in contact with the outer peripheral surface of the measuring head 100H. The pressing member 112 has a cross-sectional shape extending in the Y direction so that the measuring head 100H and the pressing member 112 can be inserted into the insertion hole 111h in a state where they are aligned in the Y direction. The pressing member 112 is formed with a through hole 112a that penetrates the side surface. The pressing member 112 is disposed in the insertion hole 111 h of the main body member 111. In this state, the fixing screw 113 a is fitted into the screw hole 111 a of the main body member 111.

  In this case, the fixing screw 113a inserted into the screw hole 111a on the one side surface 111C of the main body member 111 passes through the through hole 112a of the pressing member 112 and is fixed to the screw hole 111a on the other side surface 111D of the main body member 111. Thereby, the pressing member 112 is fixed to the main body member 111. The pressing member 112 can swing back and forth in the insertion hole 111h with the fixing screw 113a as a fulcrum. Since the operation of inserting the pressing member 112 into the insertion hole 111h is not necessary, the operation of attaching the measuring head 100H to the fixing member 110 is facilitated.

  In the example of FIGS. 11A and 11B, the measurement head 100H is attached to the fixed plate 114 above the measurement object. As shown in FIG. 11B, the fixing plate 114 is formed with a screw hole 114c and a through hole 114h. The screw hole 114 c overlaps the through hole 111 c (FIG. 10) of the main body member 111, and the through hole 114 h overlaps the insertion hole 111 h (FIG. 10) of the main body member 111. The fixing screw 113 c passes through the through hole 111 c of the main body member 111 and is fixed to the screw hole 114 c of the fixing plate 114. Thereby, the fixing member 110 is fixed to the fixing plate 114.

  The measurement head 100H is inserted into the insertion hole 111h of the main body member 111 and the through hole 114h of the fixing plate 114. In this state, the fixing screw 113b is fitted into the screw hole 111b of the main body member 111 of FIG. In this case, the fixing screw 113b inserted into the screw hole 111b on the front surface 111A of the main body member 111 presses the pressing member 112 in the insertion hole 111h. Therefore, the measuring head 100H is sandwiched between the inner peripheral surface of the insertion hole 111h and the curved surface of the pressing member 112. Thereby, the measurement head 100H is fixed to the main body member 111. As a result, the measurement head 100H is fixed to the fixed plate 114.

  FIG. 12 is a perspective view showing a plurality of measuring heads 100H fixed by a plurality of fixing members 110 of FIG. FIGS. 12A and 12B are perspective views of the measuring head 100H viewed from obliquely above and obliquely below, respectively. In the example of FIGS. 12A and 12B, a plurality of measurement heads 100H are arranged so as to be aligned in a direction orthogonal to the side surface of each fixing member 110.

  In the fixing member 110 in the present embodiment, the measuring head 100H is fixed to the fixing plate 114 by fitting the fixing screw 113b into the screw hole 111b of the front surface 111A of the main body member 111 of FIG. According to this configuration, it is not necessary to operate the fixing screw 113a on the one side surface 111C of the main body member 111 in order to detach the measuring head 100H from the fixing plate 114. Therefore, even when a plurality of measurement heads 100H are arranged so as to be aligned in a direction perpendicular to the side surface of each fixing member 110, the desired measurement head 100H can be attached to the fixing plate 114 without detaching each fixing member 110 from the fixing plate 114. Can be attached and detached individually.

  Thus, even when the plurality of fixing members 110 are arranged so that the side surfaces of the main body member 111 are close to each other, the measuring head 100H can be attached to and detached from the desired fixing member 110 without being interfered by the other fixing members 110. can do. As a result, the plurality of measuring heads 100H can be easily fixed at a desired fixing position at a high density by being close to each other.

(8) Third Reference Embodiment FIG. 13 is a horizontal sectional view of a fixing member in the third reference embodiment. As shown in FIG. 13, the fixing member 120 in the third reference embodiment includes a main body member 121 and a fixing screw 122. The main body member 121 has a substantially rectangular parallelepiped shape. The main body member 121 has a front surface 121A, a back surface 121B, one side surface 121C, another side surface 121D, an upper surface 121E, and a bottom surface (not shown).

  The main body member 121 is formed with a circular insertion hole 121h penetrating from the upper surface 121E to the bottom surface (not shown). The measurement head 100H of FIG. 1 is inserted through the insertion hole 121h. Further, the body member 121 is formed with a notch 121n that laterally separates the insertion hole 121h to the front surface 121A.

  The main body member 121 is formed with a through hole 121a that penetrates from the front end of one side surface 121C to the notch 121n. The through hole 121 a includes a counterbore for hooking the screw head of the fixing screw 122. Further, the main body member 121 is formed with a screw hole 121b that penetrates from the front end of the other side surface 121D to the notch 121n and connects to the through hole 121a. Furthermore, the main body member 121 is formed with a circular through hole 121c that penetrates from the upper surface 121E to the bottom surface (not shown).

  The fixing member 120 is disposed on the fixing plate 114 in FIG. 11B overlaps the through hole 121c of the main body member 121, and the through hole 114h of FIG. 11B overlaps the insertion hole 121h of the main body member 121. A fixing screw (not shown) passes through the through hole 121 c of the main body member 121 and is fixed to the screw hole 114 c of the fixing plate 114. As a result, the fixing member 120 is fixed to the fixing plate 114.

  The measurement head 100H is inserted into the insertion hole 121h of the main body member 121 and the through hole 114h of the fixing plate 114. In this state, the fixing screw 122 is fitted into the through hole 121a and the screw hole 121b of the main body member 121. In this case, the fixing screw 122 inserted into the through hole 121a on the one side surface 121C of the main body member 121 passes through the notch 121n and is fixed to the screw hole 121b on the other side surface 121D of the main body member 121.

  Here, by tightening the fixing screw 122, the interval between the notches 121n of the main body member 121 is reduced, and the measuring head 100H inserted through the insertion hole 121h is tightened by the one side surface 121C and the other side surface 121D. Thereby, the measurement head 100H is fixed to the main body member 121. As a result, the measurement head 100H is fixed to the fixed plate 114.

  FIG. 14 is a horizontal sectional view showing a plurality of measuring heads 100H fixed by a plurality of fixing members 120 of FIG. In the example of FIG. 14, three measurement heads 100 </ b> H are arranged so as to be aligned in a direction orthogonal to the side surface of each fixing member 120. The three fixing members 120 in FIG. 14 are referred to as fixing members 120A, 120B, and 120C, respectively.

  In the fixing members 120A to 120C in the third reference form, the fixing head 122 is fitted into the through hole 121a on the one side surface 121C and the screw hole 121b on the other side surface 121D of the main body member 121 in FIG. It is fixed to the fixing plate 114. According to this configuration, in order to detach the three measuring heads 100H from the fixing plate 114, it is necessary to operate the fixing members 120A, 120B, and 120C in an appropriate order.

  For example, when three measurement heads 100H are fixed, first, the measurement head 100H needs to be fixed to the fixing plate 114 using the fixing member 120A. Next, it is necessary to fix the measuring head 100H to the fixing plate 114 using the fixing member 120B. Finally, it is necessary to fix the measuring head 100H to the fixing plate 114 using the fixing member 120C.

  Further, when removing the measuring head 100H from the fixing member 120A, it is necessary to remove the fixing member 120B from the fixing plate 114 after removing the fixing member 120C from the fixing plate 114. As described above, the measurement head 100 </ b> H cannot be attached or detached individually by operating only the desired fixing member 120.

(9) Identification of slit position Hereinafter, the operation of the contact displacement meter 100 will be described. The scale 50 is formed so that a plurality of slits are arranged. The scale 50 is formed so that a plurality of slits are arranged. In this example, n slits are formed in the scale 50. n is an integer of 1 or more, for example 100. Each of the n slits is assigned a unique number of 1 to n. The n slits may be arranged so that the intervals between adjacent slits are all different from each other, or may be arranged so that the intervals between adjacent slits are partially equal.

  FIG. 15 is a diagram illustrating an example of the arrangement of slits. FIG. 15 shows an enlarged plan view of one end of the scale 50. In the example of FIG. 15, a plurality of slits s are arranged so that the intervals between adjacent slits s are all different from each other.

Specifically, n slits s are arranged at the position p _i so as to be arranged from one end of the scale 50. i is an integer of 1 to n. Hereinafter, the position p _i of the i-th slit s is called a slit position p _i, and the interval between the j-th slit position p _j and the (j + 1) th slit position p _{j + 1} is called a slit interval d _j . j is an integer of 1 to n-1. The (n−1) slit intervals d _{1 to} d _n−1 are different from each other. All slit intervals _dj are known and stored in advance in the memory 62 of FIG.

  The light emitted from the light projecting unit 30 in FIG. 1 passes through some of the plurality of slits s included in the scale 50 and enters the light receiving unit 40. Therefore, the received light amount distribution represented by the received light data stored in the memory 62 has a plurality of peaks corresponding to the plurality of slits s through which the light from the light projecting unit 30 has passed (hereinafter referred to as a received light amount peak). Appears.

  FIG. 16A is a diagram showing a received light amount distribution represented by received light data, and FIG. 16B is an enlarged view of a portion B in FIG. In FIG. 16, the horizontal axis indicates the pixel position of the light receiving unit 40 (hereinafter referred to as pixel position), and the vertical axis indicates the amount of received light.

  By performing data processing on the received light amount distribution of FIG. 16A, the positions of a plurality of received light amount peaks are detected in units of subpixels smaller than the pixels of the light receiving unit 40. Hereinafter, the position of the received light amount peak is referred to as a peak position. FIG. 16B shows the received light amount distribution at the pixel positions g1 to g11.

  Here, when data processing is not performed on the received light amount distribution, the pixel position g7 is the peak position. The true peak position is between the pixel positions g6 and g7. Therefore, the true peak position P is calculated in units of subpixels by performing data processing on the received light amount distribution.

  In order to detect the true peak position P in units of subpixels, data processing by various known methods can be used. For example, the true peak position P may be detected by performing centroid processing on the received light amount distribution. Alternatively, the true peak position P may be detected by fitting various curves such as a parabola to the received light amount distribution.

  FIG. 17 is a schematic diagram illustrating a relationship among the light projecting unit 30, the scale 50, and the light receiving unit 40. As shown in FIG. 17, the light emitted from the light projecting unit 30 passes through a plurality of slits s in the range C of the scale 50 while spreading at a predetermined angle, and enters the range D of the light receiving surface of the light receiving unit 40. Incident.

As described above, a plurality of peak positions P in the received light amount distribution within the range D of the light receiving surface are detected in units of subpixels by data processing using the received light data. The detected plurality of peak positions P correspond to the plurality of slit positions p _i within the range C of the scale 50, respectively.

FIG. 18 is a schematic diagram showing a plurality of peak positions P in the received light amount distribution within the range D of the light receiving surface. The horizontal axis in FIG. 18 indicates the pixel position of the light receiving unit 40. Within the range D of the light receiving surface, N peak positions P are included. The I-th peak position P called the peak position P _I. I is an integer of 1 to N, and is an integer of 1 or more and the number n of slits s or less. In the example of FIG. 18, N is 17, and the 17 peak positions P _{1 to} P ₁₇ detected by the data processing of the received light data are indicated by black circles.

An interval between adjacent peak positions P _J and P _{J + 1} is calculated. Hereinafter referred to as J-th peak position _{P J} and (J + 1) -th peak interval _{D J} the distance between the peak position _{P J + 1.} J is an integer of 1 to N-1. In the example of FIG. 18, 16 peak intervals D _{1 to} D ₁₆ between adjacent peak positions P _{1 to} P ₁₇ are calculated. Calculated (N-1) stored in advance in the number of memory 62 of the peak interval _{D 1 ~D N-1} and FIG. 1 (n-1) pieces of based on the slit spacing _{d 1 ~d n-1,} It is specified which of the _N peak positions P _{1 to} P _N corresponds to the slit positions p _{1 to pn} .

(10) Absolute position of contact N With the above method, N slit positions p _{x to} p _{x + (N−1)} corresponding to _N peak positions P _{1 to} P _N in the received light amount distribution are specified. At the same time, the numbers of the plurality of slits s are specified. x is an integer of 1 to n- (N-1). At this time, the relative positions of the plurality of slits s are specified, but the absolute positions of the plurality of slits s are not specified. The absolute position of an arbitrary slit s of the scale 50 is calculated by the following procedure.

FIG. 19 is a diagram for explaining the procedure for calculating the absolute position of the slit s. In the procedure of FIG. 19, the absolute position of any slit s _a the light passes through from the light projecting unit 30 is calculated. Here, the absolute position of the slit _{s a} is the distance _{l a} slit _{s a} from the optical axis 30o of the light projecting unit 30.

Two slits s _b and s _c located on both sides of the slit s _a are selected in advance. In the example of FIG. 19, the slits _s b, _{s c} is the slit s located on both sides of the slit _{s a,} the spacing between the slits _s b, _{s c} is the _{d bc.} Since the numbers of the slits s _{a to} s _c are specified by the above method, the interval d _bc is also specified. By the light from the light emitting unit 30 passes through the slit _s a ~s _c, the peak of the received light amount distribution appears to peak position _P a to P _c corresponding respectively to the slits _s a ~s _c.

The position P0 of the optical axis 30o on the light receiving surface of the light receiving unit 40 (hereinafter referred to as the optical axis position) P0 is known. Based on the received light data, with the distance _{L a} from the optical axis position P0 to the peak position _{P a} is calculated, the peak position _P b, the distance _{D bc} between _{P c} is calculated. Subsequently, the ratio (D _bc / d _bc ) of the interval D _bc to the interval d _bc is calculated as the magnification A. Then, the distance L _a by dividing the magnification A, the distance l _a is calculated.

The distance from each slit s to the tip of the contact 20 is known. Therefore, based on the absolute position of the slit s _a, it is possible to calculate the absolute position of the contactor 20. When the contact 20 comes into contact with the surface of the measurement object, the contact 20 is displaced. By subtracting the absolute position of the contact 20 before the contact 20 contacts the surface of the measurement object from the absolute position of the contact 20 when the contact 20 contacts the surface of the measurement object. Twenty displacements can be calculated.

  In this way, the displacement of the contact 20 is calculated based on the change in the absolute position of the slit s. Therefore, the position of any slit s before the contact 20 abuts on the surface of the measurement object, the position of any other slit s after the contact 20 abuts the surface of the measurement object, and the space between the slits s The displacement of the contact 20 can be calculated based on the interval.

  Therefore, even when some of the slits s are displaced outside the irradiation range of the light from the light projecting unit 30 due to the contact of the contact 20 with the surface of the measurement object, the absolute positions of the other slits s are calculated. Thus, the displacement of the contact 20 can be calculated. Thereby, the displacement of the contact 20 having a longer dimension than the light irradiation range from the light projecting unit 30 to the scale 50 can be calculated.

  In the present embodiment, the absolute positions of the plurality of slits s through which the light from the light projecting unit 30 has passed are calculated, and the absolute position of the contact 20 is determined based on the absolute positions of the plurality of slits s. The absolute position of the contactor 20 is calculated by averaging the absolute position of the contactor 20 calculated based on the plurality of slits s. The displacement of the contact 20 is calculated by calculating the change in the absolute position of the contact 20.

  Thereby, the displacement of the contact 20 can be calculated with high accuracy. Further, even if the peak position corresponding to the slit s is not detected due to the adhesion of dust or the like to the slit s of the scale 50, the calculated displacement error of the contact 20 can be reduced.

  Since the scale 50 has a predetermined thickness, the refraction of the light that has passed through the slit s located near the optical axis 30o is smaller than the refraction of the light that passed through the slit s located far from the optical axis 30o. Therefore, the accuracy of calculating the absolute position of the slit s located near the optical axis 30o is higher than the accuracy of calculating the absolute position of the slit s located far from the optical axis 30o.

  Therefore, in the calculation of the absolute position of the contact 20 described above, the weight of the absolute position of the slit s near the optical axis 30o is set larger than the weight of the absolute position of the slit s far from the optical axis 30o. Thus, a plurality of absolute positions of the contact 20 are averaged. Thereby, the absolute position of the contact 20 can be calculated more accurately.

(11) Effect In the present embodiment, the measuring head 100H and the control unit 60 are connected by the cable 90. The light reception signal of the light receiving unit 40 is transmitted to the control unit 60 through the signal line 94 of the cable 90. Further, air is supplied to the cable 90 by the air supply unit 86. The supplied air is guided into the housing 10 through the passage 97 of the cable 90. Thereby, the contact 20 moves in the protruding direction. As a result, the contact 20 is set to the initial position before measurement together with the scale 50. At the time of measurement, the scale 50 moves in the X direction together with the contact 20, and the light reception signals before and after the movement of the contact 20 are processed by the control unit 60.

  According to this configuration, since air is supplied into the housing 10 through the passage 97 of the cable 90, it is not necessary to separately provide the housing 10 with the air supply unit 86 for supplying air into the housing 10. . Further, it is not necessary to provide an optical element such as a collimator lens for collimating the light between the light projecting unit 30 and the scale 50. Accordingly, it is possible to reduce the size of the contact displacement meter 100 in a direction orthogonal to the moving direction of the contact 20 while allowing the contact 20 to be moved by supplying air.

(12) Other Embodiments (a) In the above embodiment, the scale 50 has a plurality of slits s, but is not limited to this. The scale 50 may have a plurality of other light transmitting portions instead of the plurality of slits s.

  (B) In the above embodiment, the control unit 60 is provided in the relay unit 80, but is not limited thereto. When the housing 10 has a sufficiently large housing space, the control unit 60 may be housed in the housing 10. Alternatively, the control unit 60 may be housed in a housing different from the housing 10.

In the form of (c) above embodiment, although the position of the slit s _a relative to the position of the optical axis 30o of the scale 50 is calculated as an absolute position is not limited thereto. Position of the slit s _a relative to the arbitrary position of the scale 50 may be calculated as an absolute position.

  (D) In the above embodiment, the received light amount peak is a maximum peak of the received light amount that appears in the received light amount distribution when the light from the light projecting unit 30 passes through the slit, but is not limited thereto. The received light amount peak may be a minimum peak of the received light amount that appears in the received light amount distribution when the light from the light projecting unit 30 is blocked by a portion other than the slit of the scale 50 (light shielding unit).

(E) In the above embodiment, the magnification A is determined based on the interval d _bc between the slits s _b , s _c located on both sides of the arbitrary slit s _a and the peak positions P _b , corresponding to the slits s _b , s _c , respectively. Although it is a ratio with the space _| interval _Dbc between _Pc, it is not limited to this. The magnification A may be a ratio between an interval between any two slits and an interval between peak positions corresponding to these.

  (F) In the above embodiment, the two light emitting units 15 and 16 of the measuring head 100H are provided, but the present invention is not limited to this. One light emitting unit may be provided in the measurement head 100H, or three or more light emitting units may be provided. Or when it is not necessary to display the measurement result of the contact-type displacement meter 100 simply, a light emission part does not need to be provided in the measurement head 100H.

  (G) In the above embodiment, the main body member 111 of the fixing member 110 is fixed to the fixing plate 114 by the fixing screw 113c, but is not limited thereto. The main body member 111 may be fixed to the fixing plate 114 by an adhesive or welding. In this case, the through hole 111 c is not formed in the main body member 111. Further, the screw hole 114 c is not formed in the fixing plate 114.

  (H) In the above-described embodiment, the configuration (FIG. 6) for supplying control signals to the two light emitting units 15 and 16 and the light receiving unit 40 using the common signal line 96 is applied to the contact displacement meter 100 of the air supply type. However, it is not limited to this. The configuration of FIG. 6 can be applied to other contact displacement meters other than the air supply type contact displacement meter 100.

  (I) In the above embodiment, the fixing member 110 is used to fix the measuring head 100H of the contact displacement meter 100 of the air supply type, but is not limited to this. The fixing member 110 can also be used to fix a measurement head of another contact displacement meter other than the air supply type contact displacement meter 100.

(13) Correspondence between each component of claim and each part of embodiment The following describes an example of a correspondence between each component of the claim and each part of the embodiment. It is not limited.

  In the above embodiment, the measurement head 100H is an example of a measurement unit, the control unit 60 is an example of a processing unit, and the cables 90 and 1 are examples of first and second cables, respectively. The air supply unit 86 is an example of an air supply unit, the case 10 is an example of a case, the contact 20 is an example of a contact, the slit s is an example of a translucent part, and the scale 50 is a scale. It is an example.

  The light projecting unit 30 is an example of a light projecting unit, the light receiving unit 40 is an example of a light receiving unit, the signal lines 94 and 96 are examples of first and second signal lines, and the passage 97 is an example of a passage. It is. The contact displacement meter 100 is an example of a contact displacement meter, the relay unit 80 is an example of a relay unit, the display unit 70 is an example of a display unit, and the light emitting units 15 and 16 are examples of a light emitting unit. The fixing member 110 is an example of a fixing member.

  The front surface 111A is an example of an end surface, the one side surface 111C, 111D is an example of a side surface, the main body member 111 is an example of a main body member, and the fixing screw 113b is an example of a holding member and a first screw member. The pressing member 112 is an example of a holding member and a pressing member, the insertion hole 111h is an example of an insertion hole, the screw hole 111b and the through hole 111c are examples of first and second through holes, respectively, and the fixing screw 113c. Is an example of a second screw member.

  As each constituent element in the claims, various other elements having configurations or functions described in the claims can be used.

  The present invention can be effectively used for various contact displacement meters.

DESCRIPTION OF SYMBOLS 1,90,90A, 90B Cable 10,10A Case 11 Shaft 12 Spring 13 Scale holding part 14 Optical system holding part 14a, 14b Support piece 15, 16 Light emitting part 17 Window part 20, 20A Contact 30 Light projecting part 30o Light Axis 31 Electric circuit 40 Light receiving part 41, 84 Circuit board 50 Scale 60 Control part 61 CPU
62 memory 63 A / D converter 64 D / A converter 70 display unit 80, 80A relay unit 81 casing unit 81a, 81b opening 82, 85 connection unit 83 lid body unit 86, 86A air supply unit 86a closing member 86b, 86B Supply port 86h Ventilation hole 91-96, 96A-96C Signal line 97 Passage 100, 100A Contact displacement meter 100H, 100HA Measuring head 110, 120, 120A-120C Fixing member 111, 121 Body member 111a, 111b, 114c, 121b Screw hole 111c, 112a, 114h, 121a, 121c Through-hole 111h, 121h Insertion hole 111A, 121A Front 111B, 121B Rear 111C, 121C One side 111D, 121D Other side 111E, 121E Top 111F Bottom 112 Press member 113a-1 13c, 122 Fixing screw 121n Notch B1, B2 Buffer circuit C1, C2 Comparator P0 Optical axis position R1, R2, R2A, R3A Protection resistance R3 Resistance s Slit

Claims (10)

A measuring section;
A processing unit for processing an output signal of the measurement unit;
A first cable connected between the measurement unit and the processing unit;
An air supply unit for supplying air to the first cable;
The measuring unit is
A housing,
A contact supported by the housing so as to be movable in one direction;
A scale having a plurality of light-transmitting portions arranged in the one direction, and configured to be movable in the one direction together with the contact;
A light projecting unit for irradiating the scale with non-parallel light;
A light receiving portion that receives the non-parallel light transmitted through the plurality of light transmitting portions of the scale,
The light projecting unit, the scale, and the light receiving unit are provided in the housing so as to be aligned in a direction intersecting the one direction,
The first cable includes a first signal line that transmits an output signal of the light receiving unit to the processing unit, and air supplied by the air supply unit so as to move in a direction in which the contact protrudes. A contact displacement meter including a passage leading into the housing. A relay unit connected to the first cable;
A display unit for displaying a processing result of the processing unit;
A second cable connected between the relay unit and the display unit;
The contact displacement meter according to claim 1, wherein the air supply unit is provided in the relay unit. The contact displacement meter according to claim 2, wherein the processing unit is provided in the relay unit. The measuring unit is
And further including at least one light emitting unit provided in the housing,
The processing unit controls a light emitting operation of the at least one light emitting unit based on a processing result of an output signal of the light receiving unit, and generates a control signal for controlling a light receiving operation of the light receiving unit,
The said 1st cable further contains the 2nd signal wire | line which transmits the control signal produced | generated by the said process part to the said at least 1 light emission part and the said light-receiving part of the said measurement part. A contact displacement meter according to claim 1. The at least one light emitting unit includes a plurality of light emitting units operating at different voltages,
The contact displacement meter according to claim 4, wherein the processing unit controls light emitting operations of the plurality of light emitting units by changing a voltage of the control signal. Each of the plurality of light emitting units is a light emitting diode,
The contact displacement meter according to claim 5, wherein forward voltages of the plurality of light emitting units are different from each other. A fixing member configured to fix the measurement unit at a desired fixing position;
The housing is formed to extend in the one direction,
The fixing member is
A body member formed to extend in the other direction intersecting with the one direction, and having a pair of side surfaces facing each other, and an end surface;
A holding member that holds the housing of the measurement unit on the main body member,
The main body member has an insertion hole that penetrates in the one direction and into which the housing is inserted, and a first through hole that penetrates from the end surface to the insertion hole,
The said housing | casing is pressed by the said holding member through the said 1st through-hole of the said main body member in the state in which the said housing | casing was inserted in the said insertion hole. Contact displacement meter. The holding member is
A pressing member inserted into the insertion hole;
A first screw member inserted into the first through hole,
The insertion hole has a cross-sectional shape extending in the other direction so that the housing and the pressing member can be inserted in a state of being aligned in the other direction,
The first screw member inserted into the first through hole presses the pressing member, and the pressing member presses the casing, whereby the casing is held by the body member. The contact displacement meter according to claim 7. The contact displacement meter according to claim 8, wherein the pressing member is provided so as to be swingable in the other direction within the insertion hole. The main body member further has a second through hole penetrating in the one direction,
The second through hole is provided so as to be aligned with the insertion hole in the other direction,
The contact displacement meter according to any one of claims 7 to 9, wherein the main body member is fixed at the fixing position by a second screw member inserted into the second through hole.

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