JP2016061682A - Contact type displacement gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact type displacement gauge with improved durability.SOLUTION: A contactor 20 protrudes from an internal space V of a casing 10 through an opening H thereof to the outside of the casing 10. A seal member 1 is mounted between an inner surface of the casing 10 and an outer surface of the contactor 20. When air is not supplied from an air supply part to the internal space V, a space between the outer surface of the contactor 20 and the inner surface of the casing 10 is sealed with the seal member 1. Meanwhile, when air is supplied from the air supply part to the internal space V, the contactor 20 is pushed out in one direction while the air in the internal space V is discharged to the outside through the opening H.SELECTED DRAWING: Figure 6

Description

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

  In general, a contact displacement meter has a contact that is in contact with the surface of an object and is linearly movable in one direction (see, for example, Patent Document 1).

  The length measuring sensor (contact displacement meter) of Patent Document 1 includes a rod-shaped movable part and a holder. A contact that makes contact with the inspection object is provided at the tip of the movable part. The holder holds the movable part so that it can be inserted and removed. In this length measurement sensor, the amount of displacement of the movable part relative to the holder is calculated using the change in inductance of the coil provided in the holder.

JP 2007-240225 A

  In the length measurement sensor of Patent Document 1, a dust boot made of a bellows-like resin member that can be expanded and contracted in one direction is attached to a movable portion. Dust boots prevent dust and the like from entering the holder.

  However, the bellows-like rubber member described in Patent Document 1 has low durability. For this reason, when the length measurement sensor is used for a long time, the rubber member deteriorates. In particular, when the length measuring sensor is configured to displace the movable part by supplying air into the holder, the rubber member may burst.

  An object of the present invention is to provide a contact displacement meter with improved durability.

  (1) A contact displacement meter according to the present embodiment includes a casing having an internal space and an opening, and a contact that protrudes from the internal space of the casing through the opening to the outside of the casing and is capable of moving back and forth in one direction. And a seal member mounted between the inner surface of the casing and the outer surface of the contact, and an air supply unit configured to push out the contact by supplying air to the internal space of the casing. The member seals between the outer surface of the contact and the inner surface of the casing when air is not supplied from the air supply unit to the internal space, and the air in the internal space when air is supplied from the air supply unit to the internal space. Is released to the outside through the opening.

  In this contact displacement meter, the contact protrudes from the internal space of the casing through the opening to the outside of the casing. A seal member is mounted between the inner surface of the casing and the outer surface of the contact. When air is not supplied from the air supply unit to the internal space, the space between the outer surface of the contact and the inner surface of the casing is sealed with a seal member. On the other hand, when air is supplied from the air supply unit to the internal space, the contact is pushed out in one direction, and the air in the internal space is released to the outside through the opening.

  In this case, when air is not supplied to the internal space, the space between the outer surface of the contact and the inner surface of the casing is sealed, so that almost no liquid and dust enter the internal space of the casing. Even when liquid and dust slightly enter the internal space, the liquid and dust are discharged to the outside of the internal space by the air released from the internal space when the measurement object is measured. This prevents liquid and dust from accumulating in the internal space. According to this configuration, it is not necessary to provide the contact displacement meter with a bellows-like rubber member having low durability in order to prevent liquid and dust from entering the internal space. As a result, the durability of the contact displacement meter can be improved.

  (2) The seal member is formed of an elastic member having a shape restoring force so as to surround the outer surface of the contactor, and has an inner wall part that contacts the outer surface of the contactor, and an outer wall part that contacts the inner surface of the casing, The inner wall portion has a first end portion located on the opening portion side and a second end portion located on the inner space side, and the outer wall portion is a third end portion located on the opening portion side and the inner space. A fourth end portion located on the side, the first end portion and the third end portion are separated from each other, the second end portion and the fourth end portion are connected, and the air supply portion When air is supplied to the internal space, the first end and the third end approach each other, so that at least one between the outer surface and the inner wall portion of the contactor and between the inner surface and the outer wall portion of the casing. A gap may be formed.

  According to this configuration, when air is supplied from the air supply unit to the internal space, the first end portion of the inner wall portion of the seal member and the third end portion of the outer wall portion approach each other due to the pressure of the air. Thereby, a clearance gap is formed in at least one between the outer surface and inner wall part of a contactor, and the inner surface and outer wall part of a casing. On the other hand, when air is not supplied from the air supply portion to the internal space, the first end portion of the inner wall portion and the third end portion of the outer wall portion are separated by the shape restoring force of the elastic member of the seal member. Thereby, the outer surface and inner wall part of a contactor contact, and the inner surface and outer wall part of a casing contact. Therefore, a simple configuration includes a state in which a gap is formed between the outer surface of the contact and the inner surface of the casing (hereinafter referred to as an open state) and a sealed state between the outer surface of the contact and the inner surface of the casing. Can be switched.

  (3) The inner wall portion and the outer wall portion are integrally formed so as to have a substantially U-shaped or substantially V-shaped cross section and have an annular opening and an annular ridgeline, and the seal member has an annular opening facing the opening and You may arrange | position so that a cyclic | annular ridgeline may be located in internal space.

  In this case, since the seal member is integrally formed, the seal member can be easily formed, handled, and attached to the casing.

  (4) The inner wall portion may have an inclined surface facing the internal space, and the inclined surface may be inclined so as to gradually approach the contact from the second end portion side to the first end portion side.

  In this case, when air is supplied from the air supply portion to the internal space, the first end portion of the inner wall portion and the third end portion of the outer wall portion are likely to approach each other by pressing the inclined surface of the seal member. Become. Thereby, a sealing member can be made into an open state from a sealing state more easily.

  (5) The contact displacement meter may further include an urging member that urges the contact in a direction in which the contact is drawn into the casing.

  In this case, the contact is biased by the biasing member. Accordingly, when air is not supplied from the air supply unit to the internal space, the contact can be returned to the position where it is drawn into the casing with a simple configuration.

  (6) The contact displacement meter may further include a dust capturing seal disposed between the seal member and the opening inside the casing.

  In this case, dust entering the internal space of the casing from the opening is captured by the dust trap. Therefore, the amount of dust that enters the internal space can be reduced.

  (7) The contact-type displacement meter has a plurality of light-transmitting parts arranged in one direction, and a scale configured to be movable in one direction together with the contact, a light projecting part that irradiates the scale with non-parallel light, The casing further includes a light receiving section that receives non-parallel light transmitted through the plurality of light transmitting sections of the scale and outputs a light receiving signal, and a processing section that processes the light receiving signal of the light receiving section, and the casing has an opening at one end. It is a cylindrical member, and a light projection part, a scale, and a light-receiving part may be arrange | positioned in the internal space of a casing so that it may rank with the direction which cross | intersects one direction.

  In this case, it is not necessary to provide an optical element such as a collimator lens for collimating the light between the light projecting unit and the scale. Thereby, a contact-type displacement meter can be reduced in the direction orthogonal to the moving direction of a contactor.

  (8) The contact displacement meter further includes a cable connected between the casing and the processing unit, and the cable is supplied by a signal line that transmits a light reception signal of the light receiving unit to the processing unit and an air supply unit. And a passage for guiding air into the casing.

  In this case, since the signal line and the air passage are provided in the cable, the signal line and the air passage can be combined in a compact manner. Further, it is possible to prevent the signal line and the air passage from being tangled. Thereby, the handleability of a contact-type displacement meter can be improved.

  According to the present invention, the durability of the contact displacement meter can be improved.

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 measuring head in the state where air is not supplied. It is a figure which shows the measurement head in the state in which air is supplied. It is an expanded sectional view of a seal member.

(1) Configuration of Contact Displacement Meter FIG. 1 is a block diagram showing a configuration of a contact displacement meter according to an embodiment of the present invention. FIG. 2 is a diagram showing a measuring head of the contact displacement meter of FIG. 2A shows an exploded perspective view of the measuring head, FIG. 2B shows a configuration inside the casing of the measuring head, and FIG. 2C shows an enlarged view of a portion A in FIG. 2B. . 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 casing 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 90 and 91. Including. The casing 10 is a cylindrical member having an internal space V. An opening H is formed at one end of the casing 10. The casing 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 to the internal space V of the casing 10. The cable 90 includes a plurality of signal lines and a passage that guides air to the internal space V. The relay unit 80 is connected to the display unit 70 via the cable 91.

  In this example, the control unit 60 is provided in the relay unit 80. In this case, since it is not necessary to provide the control part 60 in the casing 10, the casing 10 can be reduced in size. 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 100H, the contact 20 is attached to the casing 10 so as to protrude from the inner space V through the opening H to the outside of the casing 10 and to be movable back and forth in one direction. Hereinafter, one direction is referred to as the X direction. In this example, the casing 10 has an outer diameter substantially the same as that of the contact 20. Therefore, the measuring head 100H has an elongated shape as a whole. Thereby, the displacement of the measurement object can be measured through a narrow space. In addition, the measuring head 100H can be easily stored and carried.

  As shown in FIGS. 2A and 2B, the casing 10 includes a main body casing 10a, a holding casing 10b, a tip casing 10c, and a cover 10d. The casing 10 is provided with seal members 1, 11, 12 and a plurality of other waterproof seal members (not shown). In this example, the seal member 1 is, for example, a packing, the seal member 11 is, for example, an O-ring, and the seal member 12 is, for example, a dust trap (dust seal).

  The main body casing 10a has a substantially cylindrical shape. An internal space V in FIG. 1 is formed inside the main body casing 10a. The scale holding unit 13, the optical system holding unit 14, the spring 15, the light projecting unit 30, the light receiving unit 40, and the scale 50 are accommodated in the internal space V of the main body casing 10a.

  The holding casing 10b and the tip casing 10c have a substantially cylindrical shape. The cover 10d has a cup shape in which a circular opening H is formed at the bottom. In this example, the volume of the internal space V of the main body casing 10a is larger than the internal volume of each of the holding casing 10b, the tip casing 10c, and the cover 10d.

  The contact 20 includes a contact part 21, a shaft part 22 and a bearing part 23. Hereinafter, one end of the shaft portion 22 is referred to as a front end, and the other end of the shaft portion 22 is referred to as a rear end. The contact portion 21 is attached to the tip of the shaft portion 22, and the bearing portion 23 is attached to the substantially central portion of the shaft portion 22. A spring 15 is fitted to the shaft portion 22 from the rear end portion, and the scale holding portion 13 is attached. The spring 15 is provided to urge the contact 20 toward the rear end of the measuring head 100H. 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.

  The holding casing 10b is attached so as to protrude from the inside of the main body casing 10a to the tip. With the scale holding part 13, the optical system holding part 14, the spring 15, the light projecting part 30, the light receiving part 40, and the scale 50 accommodated in the internal space V of the main body casing 10 a, the holding casing 10 b is interposed via the seal member 11. A tip casing 10c is attached to the tip. The space between the holding casing 10 b and the tip casing 10 c is sealed by the seal member 11. The tip of the shaft portion 22 of the contact 20 and the contact portion 21 protrude from the tip of the tip casing 10c. The seal member 1 is mounted between the inner peripheral surface of the tip casing 10c and the outer peripheral surface of the shaft portion 22.

  The cover 10d is attached to the tip of the tip casing 10c with the bottom facing the tip of the measuring head 100H. The tip of the shaft portion 22 of the contact 20 and the contact portion 21 protrude from the circular opening H at the bottom of the cover 10d. The seal member 12 is disposed between the inner peripheral surface of the cover 10d and the outer peripheral surface of the shaft portion 22.

  A cable 90 is connected to the rear end of the main casing 10a. Air is supplied to the internal space V of the main body casing 10a from the relay portion 80 of FIG. Due to the pressure of the supplied air, the contact 20 and the scale 50 are integrally pushed in the X direction with respect to the casing 10 until the contact portion 21 comes into contact with the measurement object.

  As shown in FIG. 2C, the optical system holding unit 14 has two support pieces 14 a and 14 b extending in parallel with 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 14b of the optical system holding unit 14 via the circuit board 41 of FIG. 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 scale holding unit 13 and the optical system holding unit 14 are accommodated in the casing 10. Accordingly, the light projecting unit 30 and the light receiving unit 40 face each other with the scale 50 interposed therebetween in the casing 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 51. Each slit 51 is given a unique number.

  The light projecting unit 30 is, for example, an LED (light emitting diode). 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. Therefore, the light emitted from the light projecting unit 30 is received by the light receiving unit 40 through a part of the slits 51 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 of FIG. 1 through the circuit board 41 and the cable 90. Is output.

  According to this configuration, it is not necessary to provide an optical element such as a collimator lens for collimating light between the light projecting unit 30 and the scale 50. Thereby, the measuring head 100H can be reduced in size in the X direction.

  As shown in FIG. 1, the control unit 60 includes a CPU (central processing unit) 61, a memory 62, and an A / D (analog / digital) converter 63. 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 91.

  In this example, one set of the casing 10, the contact 20, the light projecting unit 30, the light receiving unit 40, and the scale 50 constitute one measuring head 100 </ b> H. A plurality of measurement heads 100H can be connected to one display unit 70 using a plurality of sets of cables 90 and 91 and a 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 is formed on the bottom surface of the housing portion 81. The cable 90 is connected to the connection portion 82 via a seal member.

  1 is provided with a circuit board 84 on which the control unit 60 of FIG. 1 is mounted, and a connection unit 85 to which the cable 91 of FIG. 1 is connected. 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 via a seal member 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. Accordingly, the measurement head 100 </ b> H and the control unit 60 are connected by the plurality of signal lines 96 provided in the cable 90. The cable 91 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.

  According to this configuration, since the signal line 96 and the air passage 97 are provided in the cable 90, the signal line 96 and the air passage 97 can be combined in a compact manner. Further, the signal line 96 and the air passage 97 are prevented from being tangled. Thereby, the handleability of the contact displacement meter 100 can be improved.

(3) Dust-proof structure FIG. 5 is a diagram showing the measurement head 100H in a state where air is not supplied. FIG. 5A shows a side view of the measuring head 100H, and FIG. 5B shows an enlarged sectional view taken along line BB of the measuring head 100H in FIG. FIG. 6 is a diagram illustrating the measurement head 100H in a state where air is supplied. 6A shows a side view of the measuring head 100H, and FIG. 6B shows an enlarged sectional view taken along the line CC of the measuring head 100H in FIG. 6B. FIG. 7 is an enlarged cross-sectional view of the seal member 1.

  As shown in FIGS. 5B and 6B, in the measuring head 100H, the seal member 12 is held between the outer surface at the tip of the tip casing 10c and the inner surface at the bottom of the cover 10d. Thereby, the seal member 12 is fixed between the inner peripheral surface of the cover 10d and the outer peripheral surface of the shaft portion 22.

  The inner peripheral surface of the seal member 12 contacts the outer peripheral surface of the shaft portion 22 so that the shaft portion 22 can slide in the X direction. In this state, the seal member 12 seals between the shaft portion 22 and the tip casing 10c. In this case, liquid and dust that enter the casing 10 from the opening H are captured. Therefore, the amount of liquid and dust that enters the internal space V of the casing 10 can be reduced.

  The seal member 1 is disposed so as to surround the outer peripheral surface of the shaft portion 22. The seal member 1 is formed of an elastic member (in this example, rubber) having a shape restoring force. As shown in FIG. 7, the seal member 1 has an inner wall portion 2 and an outer wall portion 3.

  The inner wall portion 2 has end portions E1 and E2, and the outer wall portion 3 has end portions E3 and E4. The end E1 and the end E3 are separated from each other. Therefore, an annular opening 4 is formed between the end portions E1 and E3. The end E2 and the end E4 are connected. Therefore, an annular ridge line 5 is formed between the end portions E2 and E4. Thereby, the inner wall part 2 and the outer wall part 3 are integrally formed so that a cross-sectional substantially U shape may be made.

  As shown in FIGS. 5B, 6B, and 7, the seal member 1 has the inner wall portion 2 in contact with the outer peripheral surface of the shaft portion 22 and the outer wall portion 3 on the inner peripheral surface of the tip casing 10c. Arranged to touch. In the present embodiment, the outer wall portion 3 is fixed to the tip casing 10c.

  Here, the end portions E1 and E3 are located on the opening H side (front end side), and the end portions E2 and E4 are located on the inner space V side (rear end side). Therefore, the seal member 1 is arranged such that the annular opening 4 faces the tip and the annular ridge 5 is positioned in the internal space V. The inner peripheral surface 2s of the inner wall portion 2 facing the inner space V is inclined so as to gradually approach the shaft portion 22 from the end portion E2 side to the end portion E1 side.

  The position of the contact 20 in FIGS. 5A and 5B is referred to as an initial position. The spring 15 biases the contact 20 in a direction in which the contact 20 is pulled into the casing 10. Therefore, when air is not supplied to the measuring head 100H, the contact 20 is held at the initial position where it is drawn into the casing 10 by the biasing force of the spring 15 in FIG. Air is supplied to the measuring head 100H. In this case, the pressure applied to the contact 20 by the air is larger than the urging force applied to the contact 20 by the spring 15. As a result, as shown in FIGS. 6A and 6B, the contact 20 moves in the X direction from the initial position until the contact portion 21 comes into contact with the measurement object.

  When air is not supplied from the air supply portion 86 of FIG. 1 to the internal space V, as shown in FIG. 5B, the inner peripheral surface 2s of the inner wall portion 2 of the seal member 1 and the outer peripheral surface of the shaft portion 22 Touch. In this case, the seal member 1 seals the space between the outer peripheral surface of the shaft portion 22 and the inner peripheral surface of the tip casing 10c. Therefore, almost no liquid and dust enter the internal space V from the opening H. A state where the outer peripheral surface of the shaft portion 22 and the inner peripheral surface of the tip casing 10c are sealed is referred to as a sealed state.

  On the other hand, when air is supplied from the air supply unit 86 to the internal space V, the contact 20 is moved by the pressure of the air, as shown in FIG. Further, the supplied air applies pressure to the inner peripheral surface 2 s of the inner wall portion 2 of the seal member 1. As a result, the end E1 of the inner wall 2 approaches the end E3 of the outer wall 3. In this example, since the inner peripheral surface 2s is inclined, when the air pushes the inner peripheral surface 2s, the end E1 of the inner wall 2 and the end E3 of the outer wall 3 are more likely to approach each other.

  In this case, a minute gap is formed between the outer peripheral surface of the shaft portion 22 and the inner peripheral surface 2 s of the inner wall portion 2. As a result, a part of the air in the internal space V is released to the outside through the opening H as indicated by an arrow in FIG. A state in which a gap is formed between the outer peripheral surface of the shaft portion 22 and the inner peripheral surface 2s of the inner wall portion 2 is referred to as an open state.

  When the supply of air is stopped, the state between the outer peripheral surface of the shaft portion 22 and the inner peripheral surface 2s of the inner wall portion 2 is sealed from the open state due to the shape restoring force of the elastic member of the seal member 1. Return to. Thus, the open state and the sealed state can be switched with a simple configuration.

  According to this configuration, almost no liquid and dust enter the internal space V of the casing 10. Even when liquid and dust slightly enter the internal space V, the liquid and dust are discharged outside the internal space V by the air released from the internal space V when measuring the measurement object. As a result, accumulation of liquid and dust in the internal space V is prevented.

(4) Effect In the present embodiment, the contact 20 protrudes from the internal space V of the casing 10 to the outside of the casing 10 through the opening H. The seal member 1 is mounted between the inner peripheral surface of the tip casing 10c and the outer peripheral surface of the shaft portion 22. When air is not supplied from the air supply portion 86 to the internal space V, the seal member 1 seals the space between the outer peripheral surface of the shaft portion 22 and the inner peripheral surface of the tip casing 10c. On the other hand, when air is supplied from the air supply unit 86 to the internal space V, the contact 20 is pushed out in one direction, and air in the internal space V is released to the outside through the opening H.

  In this case, when air is not supplied to the internal space V, the space between the outer peripheral surface of the shaft portion 22 and the inner peripheral surface of the tip casing 10c is sealed, so that almost no liquid and dust enter the internal space V of the casing 10. . Even when liquid and dust slightly enter the internal space V, the liquid and dust are discharged outside the internal space V by the air released from the internal space V when measuring the measurement object. Thereby, accumulation of liquid and dust in the internal space V is prevented. According to this configuration, it is not necessary to provide the contact displacement meter 100 with a bellows-like rubber member having low durability in order to prevent liquid and dust from entering the internal space V. As a result, the durability of the contact displacement meter 100 can be improved.

(5) Other Embodiments (a) In the above embodiment, the measurement head 100H is provided with the seal member 12 that prevents liquid and dust from entering the internal space V of the main body casing 10a. However, the present invention is not limited to this. . The seal member 12 may not be provided on the measurement head 100H. Even in this case, the liquid and dust in the internal space V are discharged to the outside by the air released from the main body casing 10a when measuring the measurement object. Therefore, accumulation of liquid and dust in the internal space V is prevented.

  (B) In the said embodiment, although the sealing member 1 has a cross-sectional substantially U shape, it is not limited to this. The seal member 1 may have a substantially V-shaped cross section, or may have another cross-sectional shape.

  (C) In the above embodiment, the spring 15 is used as a biasing member that pressurizes the contact 20 toward the rear end of the measuring head 100H, but is not limited thereto. An elastic body such as rubber may be used as the urging member. Alternatively, a magnetic body may be used as the urging member, and the contact 20 may be drawn into the casing 10 by a magnetic force.

  (D) In the above embodiment, the contact displacement meter 100 has a gap between the outer peripheral surface of the shaft portion 22 and the inner wall portion 2 of the seal member 1 when air is supplied to the internal space V of the casing 10. However, the present invention is not limited to this. The contact displacement meter 100 is configured such that a gap is formed between the inner peripheral surface of the tip casing 10 c and the outer wall 3 of the seal member 1 when air is supplied to the internal space V of the casing 10. Also good.

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

(6) 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 internal space V is an example of an internal space, the opening H is an example of an opening, the casing 10 is an example of a casing, the contact 20 is an example of a contact, and a seal The member 1 is an example of a seal member. The air supply portion 86 is an example of an air supply portion, the contact displacement meter 100 is an example of a contact displacement meter, the inner wall portion 2 is an example of an inner wall portion, and the outer wall portion 3 is an example of an outer wall portion, The end portions E1 to E4 are examples of first to fourth end portions, respectively.

  The annular opening 4 is an example of an annular opening, the annular ridge line 5 is an example of an annular ridge line, the inner peripheral surface 2s is an example of an inclined surface, the spring 15 is an example of a biasing member, and the seal member 12 is dust. This is an example of a capture seal, and the scale 50 is an example of a scale. The light projecting unit 30 is an example of a light projecting unit, the slit 51 is an example of a light transmitting unit, the light receiving unit 40 is an example of a light receiving unit, the control unit 60 is an example of a processing unit, and the cable 90 is a cable. The signal line 96 is an example of a signal line, and the passage 97 is an example of a passage.

  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.

Seal members 1, 11, 12
DESCRIPTION OF SYMBOLS 2 Inner wall part 2s Inclined surface 3 Outer wall part 4 Annular opening 5 Annular ridgeline 10 Casing 10a Main body casing 10b Holding casing 10c Tip casing 10d Cover 13 Scale holding part 14 Optical system holding part 14a, 14b Support piece 15 Spring 20 Contact 21 Contact part 22 Shaft portion 23 Bearing portion 30 Light emitting portion 30o Optical axis 31 Electric circuit 40 Light receiving portion 41, 84 Circuit board 50 Scale 51 Slit 60 Control portion 61 CPU
62 Memory 63 A / D converter 70 Display unit 80 Relay unit 81 Housing unit 81a, 81b Opening 82, 85 Connection unit 83 Cover body 86 Air supply unit 86a Closing member 86b Supply port 86h Ventilation hole 90, 91 Cable 96 Signal Line 97 Passage 100 Contact displacement meter 100H Measuring head E1 to E4 End H Opening V Internal space

Claims (8)

A casing having an internal space and an opening;
A contact provided to protrude from the internal space of the casing to the outside of the casing through the opening and to be able to advance and retreat in one direction;
A seal member mounted between the inner surface of the casing and the outer surface of the contact;
An air supply unit configured to push out the contact by supplying air to the internal space of the casing;
The seal member seals between the outer surface of the contact and the inner surface of the casing when air is not supplied from the air supply unit to the internal space, and air is supplied from the air supply unit to the internal space. A contact displacement meter configured to release air in the internal space to the outside through the opening when it is applied. The seal member is formed of an elastic member having a shape restoring force so as to surround the outer surface of the contact, and has an inner wall portion that contacts the outer surface of the contact, and an outer wall portion that contacts the inner surface of the casing. ,
The inner wall has a first end located on the opening side and a second end located on the inner space side, and the outer wall is a third end located on the opening side. An end portion and a fourth end portion located on the inner space side, wherein the first end portion and the third end portion are separated from each other, and the second end portion and the fourth end portion Are connected to
When air is supplied from the air supply unit to the internal space, the first end and the third end approach each other, so that the contact between the outer surface of the contact and the inner wall and the casing The contact displacement meter according to claim 1, wherein a gap is formed in at least one of an inner surface and the outer wall portion. The inner wall portion and the outer wall portion are integrally formed so as to have a substantially U-shaped or substantially V-shaped cross section and have an annular opening and an annular ridgeline, and the sealing member includes the annular opening and the annular opening. The contact-type displacement meter according to claim 2, wherein the contact-type displacement meter is disposed so as to face and the annular ridge line is located in the internal space. The inner wall portion has an inclined surface facing the internal space, and the inclined surface is inclined so as to gradually approach the contact from the second end portion side to the first end portion side. Item 4. The contact displacement meter according to Item 2 or 3. The contact-type displacement meter as described in any one of Claims 1-4 further provided with the urging member which urges | biases the said contactor in the direction which draws in the said casing. The contact displacement meter according to claim 1, further comprising a dust trapping seal disposed between the seal member and the opening inside the casing. 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 unit that receives the non-parallel light transmitted through the plurality of light transmitting units of the scale and outputs a light reception signal;
A processing unit for processing a light reception signal of the light receiving unit,
The casing is a cylindrical member having the opening at one end,
The contact type according to any one of claims 1 to 6, wherein the light projecting unit, the scale, and the light receiving unit are arranged in the internal space of the casing so as to be aligned in a direction intersecting the one direction. Displacement meter. A cable connected between the casing and the processing unit;
The contact displacement meter according to claim 7, wherein the cable includes a signal line that transmits a light reception signal of the light receiving unit to the processing unit, and a passage that guides the air supplied by the air supply unit into the casing. .

Images