JP6267522B2 - Sensor device - Google Patents

Description

  The present invention relates to a sensor device that detects a temperature by pressing against an object to be measured, and particularly relates to measures for improving detection accuracy.

  For example, as disclosed in Patent Document 1, a sensor device that detects a temperature by pressing against a measurement object is known. This sensor device includes a casing (probe), a protective tube inserted at the tip of the casing, and a thermocouple attached to the tip of the protective tube. The thermocouple has a flat portion that comes into contact with the measurement object. In this sensor device, the temperature of the measurement object is detected by grasping the casing with a hand, pressing the tip of the protective tube against the measurement object, and bringing the flat portion of the thermocouple into contact with the measurement object.

Japanese Unexamined Patent Publication No. 7-55548

  By the way, in the sensor device as described above, the degree of contact of the thermocouple varies depending on the pressing angle against the measurement object, and the temperature detection accuracy may be impaired. In other words, depending on the pressing angle to the measurement object, only a part of the flat portion of the thermocouple contacts the measurement object, and thus the temperature may not be detected accurately.

  The present invention has been made in view of such circumstances, and an object thereof is to improve temperature detection accuracy in a sensor device that detects temperature by bringing a thermocouple into contact with an object to be measured.

  A sensor device according to the present invention includes a thermocouple having a contact member in which a held portion and a flat contact surface are formed, and a holding member that holds the held portion of the contact member, and the contact of the contact member It is premised on a sensor device that detects the temperature of a measurement object by bringing the surface into contact with the measurement object. And the said contact member is hold | maintained at the said holding member so that rocking is possible on the point located on the central axis of the said to-be-held part orthogonal to the said contact surface.

  According to the present invention, the contact member is held so as to be swingable about a point located on the central axis of the held portion orthogonal to the contact surface as a swing center. Even when the contact member is pressed against the measurement object at an oblique angle, the contact surface can be made parallel to the surface of the measurement object by swinging the contact member. Thereby, even if the contact member is pressed against the measurement object at any angle, the entire contact surface can be reliably and easily brought into contact with the measurement object. Therefore, the temperature detection accuracy can be improved.

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a sensor device according to an embodiment. FIG. 2 is a cross-sectional view illustrating a main part of the sensor device according to the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

  The sensor device 1 of this embodiment shown in FIG. 1 is a so-called handy type sensor that directly presses against a measurement object and detects two vibrations and temperature of the measurement object. FIG. 1 shows the upper part of the sensor device 1, and the lower part is omitted.

The sensor device 1 includes a casing 5, a vibration detection mechanism 10, a holding member 20, a temperature detection mechanism 30 (thermocouple), and a signal processing circuit 40.

  The casing 5 is formed by two casing members divided in a direction perpendicular to the paper surface of FIG. 1, and they are connected by taper screws 6 and 7. A cylindrical protective tube 8 is inserted into the front end side of the casing 5. That is, the protective tube 8 is provided in a state protruding from the tip of the casing 5. The casing 5 is made of PEEK (polyether ether ketone resin), and the protective tube 8 is made of stainless steel.

  The vibration detection mechanism 10 includes a detection needle 11, a vibration transmission plate 12, two electrode plates 13 and 15, a piezoelectric element 14, and a switch fitting 18, and detects (measures) vibration of a measurement object. It is.

  The detection needle 11 is an elongated rod-like member and is inserted from the protective tube 8 to the casing 5. The proximal end side of the detection needle 11 is a small diameter portion 11b, and a male screw is formed on the outer peripheral surface. The tip 11a of the detection needle 11 has a tapered shape. The vibration transmission plate 12 is formed with a female screw and is screwed to the small diameter portion 11 b of the detection needle 11. The first electrode plate 13, the piezoelectric element 14, the second electrode plate 15, and the weight 16 are sequentially inserted into the small diameter portion 11 b of the detection needle 11 after the vibration transmission plate 12. In the small diameter portion 11 b of the detection needle 11, the vibration transmission plate 12, the electrode plates 13, 15, and the like are closely fixed to each other by tightening the nut 17.

  The detection needle 11 to which the vibration transmission plate 12 or the like is fixed in this way is held in the casing 5 by the switch fitting 18. The switch fitting 18 has an upper wall 18a in which a cut is provided from the front side to the other side of FIG. 1 and a bifurcated spring portion 18b extending downward from the end on the other side of the upper wall 18a. Is formed. The switch fitting 18 holds the upper surface of the vibration transmission plate 12 and the lower surface of the weight 16 between the upper wall 18a and the spring portion 18b. In other words, the detection needle 11 to which the vibration transmission plate 12 or the like is fixed has the weight 16 urged upward by the elastic force of the spring portion 18b, whereby the upper surface of the vibration transmission plate 12 is pressed against the lower surface of the upper wall 18a. (Contact). In the switch fitting 18, the switch is turned on when the vibration transmission plate 12 is separated from the lower surface of the upper wall 18a, and the switch is turned off when the vibration transmission plate 12 is in contact with the lower surface of the upper wall 18a. The switch fitting 18 has a side wall 18 c extending downward from the upper wall 18 a, and the side wall 18 c and the upper wall 18 a are held on the inner wall of the casing 5.

  In the casing 5, a signal processing circuit 40 is provided below the vibration detection mechanism 10. Although not shown, the two electrode plates 13 and 15 of the vibration detection mechanism 10 are electrically connected to the vibration terminals 41 and 42 of the signal processing circuit 40.

  The detection needle 11, the vibration transmission plate 12, and the switch fitting 18 are made of stainless steel, the electrode plates 13 and 15 are made of phosphor bronze, and the weight 16 is made of zirconia ceramic.

  The holding member 20 holds a detection needle 11 of the vibration detection mechanism 10 and a contact member 31 of a temperature detection mechanism 30 described later. The holding member 20 is formed in a substantially cylindrical shape, and includes a main shaft portion 21, a large diameter portion 22 and a tip portion 23 formed at both ends thereof. In the holding member 20, the main shaft portion 21 and the tip portion 23 are inserted into the protective tube 8, and the large-diameter portion 22 is located outside the protective tube 8 in the casing 5. The main shaft portion 21 of the holding member 20 has an outer diameter that is smaller than the inner diameter of the protective tube 8, and the distal end portion 23 has an outer diameter that is substantially the same as the inner diameter of the protective tube 8. In addition, two windows 21 a and 21 b are formed in the main shaft portion 21. The detection needle 11 is inserted and held in the holding member 20.

  The protective tube 8 is fitted to a protrusion 24 (shown by a broken line in FIG. 1) formed near the large-diameter portion 22 of the holding member 20 to prevent the protective tube 8 from coming off. The holding member 20 is formed of PEEK as with the casing 5.

  The temperature detection mechanism 30 includes a contact member 31 and two thermocouple wires 36 and 37, and detects (measures) the temperature of the measurement object.

  The contact member 31 is a member that is provided on the distal end side of the protective tube 8 and is pressed against and contacted with the measurement object. Each of the two thermocouple wires 36 and 37 has one end connected to the contact member 31 and the other end connected to the temperature terminals 43 and 44 of the signal processing circuit 40. The front end portion 23 of the holding member 20 is formed with one vertical groove 23c (slit) extending in the vertical direction (vertical direction in FIG. 2) on the outer peripheral surface. The two thermocouple wires 36 and 37 are wired to the signal processing circuit 40 through the vertical groove 23 c of the tip end portion 23. The contact member 31 is made of stainless steel. One of the two thermocouple wires 36 and 37 is an alumel wire and the other is a chromel wire.

  A detailed configuration of the contact member 31 will be described with reference to FIG.

The contact member 31 is held at the distal end portion 23 of the holding member 20 and is provided in a state of protruding from the protective tube 8. In the contact member 31, a contact portion 32 that comes into contact with an object to be measured is formed on the distal end side (lower side in FIG. 2), and a held portion 34 that is held by the distal end portion 23 of the holding member 20 is proximal (see FIG. In FIG. The contact member 31 has a substantially cylindrical shape with a through hole 33 formed along the central axis C of the held portion 34. In the present embodiment, the central axis C is also the central axis of the contact member 31, the detection needle 11, and the protective tube 8.

The contact portion 32 has a flange shape extending outward in the radial direction over the circumferential direction. The lower surface of the contact portion 32 is a flat contact surface 32a that is brought into contact with the measurement object. The central axis C is an axis orthogonal to the contact surface 32a.

  The detection needle 11 is inserted through the through hole 33 of the contact member 31, and the tip 11 a is provided so as to protrude from the contact surface 32 a of the contact member 31. The through hole 33 of the contact member 31 has a larger diameter than the outer diameter of the detection needle 11, and a gap is provided between the contact member 31 and the detection needle 11.

  The contact member 31 of the present embodiment is held by the distal end portion 23 of the holding member 20 so as to be swingable with a point located on the central axis C as a swing center P. Specifically, the held portion 34 of the contact member 31 is formed on a spherical surface 34 a having an outer peripheral surface whose center is the swing center P. On the other hand, the distal end portion 23 of the holding member 20 has a spherical surface 23 a corresponding to the held portion 34 of the contact member 31. The spherical surface 23a of the distal end portion 23 is configured such that the held portion 34 of the contact member 31 is inserted and slidably contacts the spherical surface 34a of the held portion 34, and the held portion 34 is swingably held. That is, the swing center P is the center of the spherical surface 34 a of the contact member 31 and the center of the spherical surface 23 a of the holding member 20. In this way, the contact member 31 can swing around the swing center P as indicated by a broken line in FIG.

  A tapered portion 23 b is formed at the distal end portion 23 of the holding member 20, with the inside of the end portion being cut off obliquely. By doing so, a constant swinging motion of the contact member 31 is allowed. On the other hand, the contact member 31 is configured to swing within a range where it does not come into contact with the detection needle 11. That is, the swinging operation of the contact member 31 is restricted to a certain range so that the contact member 31 does not contact the detection needle 11. Specifically, a swing restricting portion 35 is formed on the outer peripheral surface of the contact member 31. The swing restricting portion 35 is a corner that slightly protrudes from the outer peripheral surface of the contact member 31, and restricts the swing operation of the contact member 31 by contacting the tapered portion 23 b of the holding member 20 described above.

  In the sensor device 1, by pressing the tip of the protective tube 8 against the measurement object (for example, the surface of the steam trap) and pushing the tip 11 a of the detection needle 11 to the contact surface 32 a of the contact member 31, the switch is switched in the switch fitting 18. Turned on. The mechanical vibration of the measurement object is transmitted to the vibration transmission plate 12 through the detection needle 11 and acts on the piezoelectric element 14 as pressure fluctuation. In response to this, a voltage fluctuation occurs in the piezoelectric element 14, and a signal relating to this voltage fluctuation is sent from the electrode plates 13 and 15 to the signal processing circuit 40 to detect (measure) the vibration of the measurement object.

  In the sensor device 1, as described above, the tip 11 a of the detection needle 11 is pushed down to the contact surface 32 a of the contact member 31, so that the contact surface 32 a of the contact member 31 contacts the measurement object. Then, a potential difference is generated between the two thermocouple wires 36 and 37, and a signal related to this potential difference is sent to the signal processing circuit 40 to detect the temperature of the measurement object. The numerical values of the vibration and temperature of the measurement object detected as described above are displayed on a display unit (not shown) provided in the casing 5.

  As described above, according to the sensor device 1 of the above-described embodiment, the contact member 31 of the temperature detection mechanism 30 can be swung with the point located on the central axis C orthogonal to the contact surface 32a as the swing center P. Even if the contact member 31 is pressed against the measurement object at an angle at which the contact surface 32a is inclined with respect to the measurement object, the contact surface 32a is swung by moving the contact member 31. It can be parallel to the surface of the object. Thereby, even if the contact member 31 is pressed against the measurement object at any angle, the entire contact surface 32a can be reliably and easily brought into contact with the measurement object. Therefore, the temperature detection accuracy can be improved.

  Specifically, the outer peripheral surface of the held portion 34 in the contact member 31 is formed as a spherical surface 34a having the pivot center P as a sphere, while the holding member 20 is in sliding contact with the spherical surface 34a of the held portion 34. Since the spherical surface 23a that holds the swingable member 34 is formed, the contact member 31 can be swung reliably with a simple configuration.

  In the sensor device 1 of the above embodiment, the detection needle 11 for detecting the vibration of the measurement object is provided by being inserted into the contact member 31. Since the contact member 31 is swung within a range where it does not come into contact with the detection needle 11, the vibration of the measurement object can be accurately detected. That is, when the contact member 31 swings and contacts the detection needle 11, the vibration of the measurement object is not accurately transmitted to the vibration transmission plate 12, but such a situation can be avoided in the above embodiment.

  Although the vibration detection mechanism 10 is provided in the sensor device 1 of the above embodiment, the present invention may be configured to detect only the temperature of the measurement object by omitting the vibration detection mechanism 10.

  The present invention is useful for a sensor device that detects a temperature by being pressed against an object to be measured.

DESCRIPTION OF SYMBOLS 1 Sensor apparatus 11 Detection needle 20 Holding member 23a Spherical surface 30 Temperature detection mechanism (thermocouple)
31 Contact member 32a Contact surface 33 Through hole 34 Held portion 34a Spherical surface C Central axis P Center of swing

Claims (2)

A thermocouple having a contact member formed with a held portion and a flat contact surface; and a holding member for holding the held portion of the contact member, wherein the contact surface of the contact member is brought into contact with a measurement object. A sensor device for detecting the temperature of the measurement object,
The contact member is held by the holding member so as to be swingable about a point located on the central axis of the held portion orthogonal to the contact surface ,
The held portion of the contact member has a spherical surface whose center is the swing center on the outer peripheral surface,
The holding member has a spherical surface that is inserted into the held portion of the contact member and is in sliding contact with the spherical surface of the held portion, and holds the held portion in a swingable manner.
A through hole is formed in the contact member along the central axis of the held portion,
A detection needle that is inserted through the through hole of the contact member with a gap and that detects the vibration of the measurement object by pressing the tip against the measurement object;
At the end of the holding member where the member to be held of the contact member is inserted, a tapered portion with the inside cut off is formed,
The contact member is formed so as to protrude from an outer peripheral surface, and has a swing regulating portion that regulates the swing operation of the contact member by contacting the tapered portion so that the contact member does not contact the detection needle. sensor and wherein the are. The sensor device according to claim 1 ,
The detection needle is provided with a tip protruding from a contact surface of the contact member, and detects the vibration of the measurement object by pressing the tip against the measurement object and pushing the tip to the contact surface of the contact member. sensor and wherein the Turkey.

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