JP2006200940A - Strain measurement sensor and valve open-and-close detection sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable installation to a position to be installed easily and surely without degrading sensor accuracy. <P>SOLUTION: The strain measurement sensor comprises a housing 9 of which one end is opened, a lid 13 attached to block the opened end of the housing 9, and a strain gauge A which is fixed to the inner surface of the lid 13 to be placed in the housing 9. Part of the lid 13 is provided with an installation part 14 which extends outwardly from the perimeter of the opening of the housing 9 and of which the tip side is obliquely bent backward toward the closed end's side of the housing 9. The outer surface of an inner part 13a, which is a part of the lid 13 which is not bent backward, is abutted with the surface of an arm 8, while the part of the installation part 14 bent backward is restored, allowing an installation part 13b to be attached to the surface of the arm 8 through spot welding. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In the present invention, a strain measuring sensor that detects strain generated by external force applied to a structure such as a machine, and the strain measuring sensor are exclusively used to detect the open / closed state of a valve with strain of a stem arm. The present invention relates to a valve open / close detection sensor.

  Many valves are used in chemical plants, thermal power plants or nuclear power plants.

  Some of these valves are manually operated and others are operated automatically. Among these, when the manual handle is rotated in the valve closing direction to hold the valve body in the fully closed position, the tightening force at the fully closed position varies depending on the operator.

  If the tightening force is weak, the closing operation becomes incomplete. On the other hand, if the tightening force is too strong, there are adverse effects such as wear of the valve and fatigue of each part constituting the valve. Therefore, a special skill is required for an operator who performs a manual operation.

Therefore, when the valve is closed, a closing pressure is generated on the valve body, and the reaction force of this closing pressure acts as a force that pushes up the valve stem, causing distortion of the stem, etc. There is already known a method for providing an operator to recognize that the valve is closed by turning on a lamp with a closing signal output from the sensor (for example, see Patent Document 1). .
JP-A-5-52276

  However, the valve provided with the strain sensor described in Patent Document 1 is designed to improve the detection accuracy of the sensor only by incorporating the strain sensor in the stem that moves up and down integrally with the valve. Not.

  In addition, a conventional general strain sensor, for example, a strain gauge, is attached to the attached portion using an adhesive, but the attached portion has a complicated shape, so the strain gauge is appropriate for the attached portion. Often difficult to adhere to.

  In particular, in order to bond the strain gauge, an adhesive with a long curing time is used in order to maintain the bonding strength, and in order to increase the adhesion, it is generally possible to continue to pressurize the bonding surface until curing is completed. Is.

  Therefore, for example, when a strain gauge is bonded at a site where workability is poor and the strain gauge is not in close contact, even if the accuracy on the strain gauge, that is, the sensor side is high, the accuracy when actually installed and used. Is low, and in particular, the reproducibility after a long period of time is low.

  The present invention has been made in order to solve the above-described conventional problems, and is a strain measurement sensor that can be easily and reliably attached to an attached portion without lowering the accuracy of the sensor, And providing a valve open / close detection sensor.

According to the present invention, the above problem is solved as follows.
(1) In the strain measurement sensor, a housing that opens at least one side end of the hollow chamber, a lid that tightly closes the open end of the housing, and a strain gauge that is fixed to the front or rear surface of the lid The strain gauge connection wiring end provided in the housing and the outer periphery of the opening of the housing, sandwiching an adhesive on the front surface of the lid, and pressurizing the lid to the part to be measured, And an attachment portion for fixing the housing to the member to be measured.

(2) In the above item (1), the housing is a bottomed cylindrical body having one end opened.

(3) In the above item (1) or (2), the lid is a plate member stretched in the form of an eardrum at the opening end of the bottomed cylindrical body.

(4) In the above item (1) or (2), the lid is an elastic resin material filled in the front end of the housing so as to close the open end of the bottomed cylindrical body.

(5) In any one of the above items (1) to (4), the lid is stretched on the housing with the central portion slightly convex rearward.

(6) In any one of the above items (1) to (5), the strain gauge is a single strain gauge in which four strain detection resistor patterns arranged with the strain detection directions being complementary are used as a bridge circuit. is there.

(7) In any one of the above items (1) to (5), when the strain gauge forms a bridge circuit, four strains are used to reduce the disturbance component in a complementary manner with respect to the strain detection direction. A gauge is placed.

(8) In any one of the above items (1) to (7), the strain gauge connection wiring end is a connector connected to the strain gauge so that the balanced output of the bridge circuit can be detected.

(9) In any one of the above items (5) to (8), the bridge circuit includes a variable resistor for balancing the bridge circuit provided in the housing.

(10) In any one of the above items (1) to (9), the mounting portion extends a part of the lid and protrudes to the outer periphery of the housing.

(11) In any one of the above items (1) to (9), the attachment portion is an extension portion of a lid attachment flange provided at an opening end portion of the housing.

(12) In any one of the above items (1) to (11), the mounting portion extends outward from the outer periphery of the front opening of the housing along the opening surface, and the extended tip side is connected to the housing. Warps diagonally backwards.

(13) In any one of the above items (1) to (12), the mounting portion is discontinuous in the circumferential direction.

(14) In the valve opening / closing detection sensor, a housing that opens at least one side end of the hollow chamber, a lid that tightly closes the open end of the housing, and a front surface or a rear surface of the lid, A plurality of strain gauges forming a bridge circuit, and a connection wiring end connected to the bridge circuit and an outer periphery of the opening of the housing for measuring an equilibrium state of the bridge circuit by the plurality of strain gauges. A center part of the lid body is attached to the stem arm of the valve to be measured with an adhesive sandwiched between the mounting part and the housing is fixed to the stem arm; and the mounting part is provided in the housing. Bridge circuit adjustment that adjusts the balance of the bridge circuit at the end of the connection wiring with the measured valve either fully open or fully closed after being attached to the arm And a stage.

(15) In the above item (14), either or both of the housing and the lid are formed of a metal material, and either one or both of the metal material is projected to the outer periphery of the housing.

(16) In the above item (14), the attachment portion is fixed to the stem arm by spot welding.

(17) In any one of the above items (14) to (16), the attachment portion is fixed to the stem arm with an adhesive.

(18) In the above item (17), the adhesive is an adhesive having a faster curing rate than the adhesive that fixes the lid to the stem arm.

According to the present invention, the following effects can be obtained.
(A) According to the first aspect of the present invention, the front surface of the lid formed by attaching a strain gauge to the front surface or the rear surface is brought into contact with the mounting surface of the measured part while pressing the adhesive material between them. In order to fix the housing with the lid tightly attached close to the part to be measured, the adhesive between the part to be measured and the lid should be adhesive in a pressurized state. In addition to being solidified and solidified, the bonded portion enables measurement with little change over time for a long time in strain measurement, and the fixing of the housing and the measured portion is performed between the lid and the measured portion. After the solidification time of the adhesive material that adheres to each other, the fastening strength is not required so much, but in the situation where acceleration such as vibration is applied, the fastening strength of the housing and the location to be measured becomes stronger, so the lid body The function of protecting the adhesive surface between the measurement point and the measured part can be obtained.
Further, since the housing in which the strain gauge connection portion is housed is tightly sealed, the change with time of the sensor portion is also small.
In addition, since the installation of the strain measurement sensor does not require a high level of skill or skill, anyone can easily perform the installation work, and distortion measurement without individual differences in the installation work can be performed.
The part to be measured can be applied to a wide range of parts of the mechanical structure at almost normal temperature, and can measure a very small distortion with high accuracy.

(B) According to the invention described in claim 2, a sealed housing can be easily made.

(C) According to the invention described in claim 3, the lid body can be uniformly deformed in all directions to reduce disturbances and errors in the strain direction.

(D) According to the invention described in claim 4, even when the surface of the surface to be measured forms an irregular plane, the strain gauge portion is supported by the elastic lid, so that the strain gauge is Regardless of the inclination of the casing, bonding is performed in a state in which the measurement face is aligned with the inclination of the measurement surface. In addition, since the elastic lid is rich in heat insulation, it is possible to prevent strain disturbance of the strain gauge and perform stable strain detection.

(E) According to the invention described in claim 5, since the central part of the lid is convex, the adhesive sandwiched between the measured portion and the lid is directed from the center toward the periphery. While pressurizing to extrude, the adhesive material can be uniformly and thinly formed to form a thin adhesive layer, and distortion generated in the measurement target portion can be accurately transmitted to the lid body to increase measurement accuracy.

(F) According to the invention described in claim 6, since the four uniform resistors are produced at the time of manufacturing the strain gauge, the temperature coefficient and the rate of change in length and width are uniform, and the strain in the vertical and horizontal directions is affected. Noise components can be effectively removed by canceling out disturbance components in a conservative manner.

(G) According to the invention described in claim 7, it is possible to effectively eliminate the noise component by canceling out the disturbance components related to the distortion in the vertical direction and the horizontal direction in a conservative manner.

(H) According to the invention described in claim 8, since the strain gauge connection wiring end is used as a connector, the equilibrium state of the strain gauge can be easily measured only by connecting a measuring instrument to this connector.

(I) According to the invention described in claim 9, when the strain gauge fixed to the lid is fixed to the measurement target, the front surface of the lid is pressed to the measurement target with the adhesive interposed therebetween. Therefore, initial offset distortion occurs in the lid itself, and the unbalanced component of the bridge circuit due to this distortion is removed by the variable resistor, so that the equilibrium state of the bridge circuit in the initial setting is always balanced. Can be set as In particular, in the valve opening / closing detection sensor that detects the open / closed state of the manual valve, the complete equilibrium state is initially set as the optimal fully closed state of the valve body, so that the manual valve is opened and then returned to the optimal fully closed state again. In reproduction, the valve can be closed with high reproducibility by closing the valve in a balanced state of the bridge circuit.

(J) According to the invention described in claim 10, since the periphery of the lid is extended to form the attachment portion, a strain measurement gauge having a simple structure and high adhesion to the opening of the housing can be obtained.

(K) According to the eleventh aspect of the present invention, the lid mounting flange provided in the opening of the housing is extended to form the mounting portion, so that the structure is simple and the strain has high adhesion to the lid. In addition to creating a measurement gauge, there is a gap between the front of the lid and the part to be measured that needs to be attached, so an adhesive that sandwiches the gap between the front of the lid and the part to be measured is added. It can function as a tightening allowance for pressing.

(L) According to the invention of claim 12, by tightening the tip of the attachment portion backward, a fastening allowance is formed for pressurizing the adhesive sandwiched between the front surface of the lid and the portion to be measured, By fixing the attachment portion to the portion to be measured, the adhesive portion is naturally pressurized.

(M) According to the invention described in claim 13, by making the attachment portion discontinuous with respect to the circumferential direction, the attachment portion is easily bent forward and is sandwiched between the front surface of the lid and the portion to be measured. No excessive pressure is applied to the adhesive.

(N) According to the invention described in claim 14, the outer surface of the plate-like lid having the strain gauge tightly fixed to the back surface is pressed against the stem arm of the valve for detecting opening and closing with the adhesive interposed therebetween. The adhesive between the stem arm and the lid is solidified in a pressurized state in order to firmly secure the housing formed by abutting and tightly fastening the lid once. Adhesive strength is strong, and the adhesive part is thin and strong, making it possible to measure with little change over time in valve opening / closing detection, and the housing and stem arm Since the fixing strength is not required so much after the solidifying time of the adhesive for bonding the lid and the measured portion elapses, the fixing with the instantaneous adhesive is also possible. However, in a situation where acceleration such as vibration is applied, the fastening strength between the housing and the stem arm is better, and when the location is firmly fixed, it serves to protect the bonding surface between the lid and the stem arm. . Further, since the housing in which the strain gauge is accommodated is tightly sealed, the change with time of the sensor portion is also reduced.
Furthermore, when installing the valve open / close detection sensor, no high level of skill or skill is required, so anyone can easily perform the installation work, enabling valve open / close detection without individual differences in the installation work, and the skilled person closed. A proper fully closed state can be fixed at an initial setting in which the bridge circuit is in an equilibrium state, and any subsequent valve closing operation can be easily reproduced without requiring skill.
For detection of valve opening / closing, a bridge circuit using a pure resistance strain detection element can be applied, so that opening / closing measurement accuracy with a small detection error can be obtained even in a wide temperature atmosphere.

(O) According to the invention described in claim 15, since the stem arm and the housing can be easily fixed by electric resistance welding, the mounting operation can be easily performed in a short time.

(P) According to the invention of the sixteenth aspect, since an external force is applied to the bonded portion, spot welding that is welded while being pressurized and has a fast bonding work can improve workability.

(Q) According to the invention of claim 17, either one or both of the lid and the housing can be made of an insulating material.

(R) According to the invention described in claim 18, since an external force is applied to the bonded portion, bonding with an instantaneous adhesive can improve workability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cutaway side view of an essential part showing a state in which a strain measurement sensor according to an embodiment of the present invention is attached to a manual valve.

  As shown in FIG. 1, the manual valve (1) detects the force applied to the valve stem (2) when fully opened or fully closed to detect the open / closed state of the manual valve (1). A strain measurement sensor (hereinafter abbreviated as a sensor) (3) is provided as a sensor. In the following description, the sensor (3) is used for detecting the open / closed state of the manual valve (1), but its use is limited to the manual valve (1). It can also be used as a strain measurement sensor that detects various types of strain that occur physically.

  The manual valve (1) has a valve body (not shown) below the valve stem (2). Above the valve box (4) for housing the valve body, the male screw of the valve stem (2). A stem arm (8) in which a stem nut (6) screwed to (5) is fixed to a support ring (7) at the upper end protrudes. A sensor (3) is fixed to an appropriate position on the outer surface of the stem arm (8) as will be described later.

  2 to 7 show the sensor (3), FIG. 2 is a perspective view before being attached to the manual valve (1), and FIG. 3 is a view of FIG. 2 in a state before being attached to the stem arm (8). AA line enlarged vertical sectional view, FIG. 4 is an AA line enlarged vertical sectional view of FIG. 2 in a state of being attached to the stem arm (8), and FIG. 5 is a diagram showing an arrangement configuration of resistance elements in the strain gauge. 6 and 7 are circuit diagrams showing different examples of electrical connection states of the strain gauges.

  As shown in FIGS. 2 to 7, the sensor (3) includes a housing (9), a connector (10), an electric circuit board (11), a variable resistor (12), a lid (13), a mounting part (14 ), A strain gauge (A), and the like.

The housing (9) has a bottomed cylindrical shape and is made by press-molding a metal plate.
At the opening end which is the front surface (left side in FIG. 3) of the housing (9), a mounting flange (9a) bent at a substantially right angle toward the outer side is integrally provided.

  A flanged hole (9c) is provided at the center of the bottom wall (9b) at the rear end of the housing (9), and an operation hole (9d) is provided adjacent to the flanged hole.

The connector (10) that forms the end of the strain gauge connection wiring is made by inserting a screw shaft (10b) into a metal outer cylinder, and a positioning rod (10a) is provided in the middle of the outer peripheral surface. It has been.
The connector (10) is inserted into the housing (9) from the opening end side, and attached to the inner surface of the flanged hole (9c) with a positioning rod (10a) in contact therewith.

  After the insertion, the connector (10) and the flanged hole (9c) are preferably made airtight or watertight by soldering or using an adhesive or the like.

  As clearly shown in FIG. 2, the end surface of the screw shaft (10b) is provided with a recessed hole (15), and a plurality of connector terminals (16) are provided in each recessed hole (15). ing.

  The external connector (17) is attached to the screw shaft (10b), and the terminal (16) is electrically connected to the terminal (not shown) on the external connector (17) side, thereby balancing the bridge circuit in the sensor (3). The detection signal can be taken out.

  The terminal (16) leads to the front end of the connector (10) and can be electrically connected to a circuit on the electric circuit board (11) in the housing (9). The connection connected to the terminal (16) of the connector (10) can be directly led out of the housing (9) without going through the terminal (16).

  The inside of the connector (10) is filled with a resin material except for a portion to be a connection portion to be airtight or watertight, and the outer periphery of the housing (9) has a heat insulating property to prevent thermal disturbance. It is preferable to cover the heat insulating cover (23) made of urethane rubber or foam material.

  The electric circuit board (11) is mounted with an electric circuit for connecting each resistance element of the strain gauge (A) to the bridge circuit, and a connector (10 that forms an end portion of the strain gauge connection wiring in the housing (9). ) Is fixedly attached.

  On the rear surface of the electric circuit board (11), a variable resistor (12) that constitutes a balance adjusting means of the bridge circuit is attached.

  The resistance value can be set continuously by inserting a tool into the groove (12b) on the rear surface of the rotating shaft (12a) protruding from the rear surface of the variable resistor (12) and rotating the rotating shaft (12a). it can.

  The position of the rotary shaft (12a) corresponds to the operation hole (9d) and can be adjusted by inserting a tool from the operation hole (9d).

  The lid (13) in the first embodiment is made of metal, is rich in elasticity, and is made by pressing a relatively thin plate material into a disk shape.

  The lid (13) has a larger diameter than the flange (9a) of the housing (9), and is in contact with the flange (9a) and spot welded (P1).

  The inner part (13a) of the part corresponding to the flange (9a) of the lid (13) is substantially flat or convex slightly forward in the center, and the part outside the flange (9a) is attached As part (14), it inclines toward back.

  The strain gauge (A) is attached to the rear surface of the lid (13) before the lid (13) is attached to the housing (9).

  As shown in FIG. 5 (a) or (b), the strain gauge (A) has four elongated resistive elements (19a) (19b) whose resistance value changes according to the strain on the gauge base (18). ) (19c) (19d) are arranged in the crossing direction.

  FIG. 5 (a) shows the four resistance elements (19a), (19b), (19c) and (19d) of the strain gauge (A), in which the resistance pattern is directly formed on the gauge base (18). ) Formed a resistance pattern on separate base materials, and formed each individual resistance element (19a) (19b) (19c) (19d) on the gauge base (18). Is. In the case of (b), the gauge base (18) can be omitted, and can be directly bonded to the outer surface of the lid (13).

  Each of the resistance elements (19a), (19b), (19c), and (19d) has different sensitivities depending on the direction that extends or contracts at right angles, but in this example, in consideration of this point, the resistance elements (19a) and Between (19b), (19b) and (19c), (19c) and (19d), (19d) and (19a), alternately changing the vertical direction and the horizontal direction, Are arranged so that the vertical and horizontal distortion components complementarily cancel the disturbance components in the direction requiring measurement.

  As a material of the gauge base (18), for example, a material having flexibility and excellent electrical insulation, such as bakelite, is used.

The strain gauge (A) is bonded and fixed to substantially the center of the rear surface of the lid (13) by applying an adhesive (20) to the front surface of the gauge base (18).
The bonding operation at this time is performed in a complete condition in the factory, and a sufficiently strong bonding is performed.

  The resistance elements (19a), (19b), (19c), and (19d) of the strain gauge (A) are attached to the bridge circuit using the electric circuit and the lead wire (21) on the electric circuit board (11). The adhesive is fixed to the stem arm and electrically connected.

  6 and 7 show examples of electrical connection of the bridge circuit.

  In the electrical connection shown in FIG. 6, a variable resistor (12) for adjusting the balance is provided in parallel with any one of the resistance elements, for example, the resistance element (19b) to adjust the balance of the bridge circuit. .

  In the electrical connection of FIG. 7, the balance detection end of the bridge circuit is used as a sliding terminal of the variable resistor (12) to adjust the balance of the bridge circuit.

  After the strain gauge (A) is attached to the rear surface of the lid (13) and the resistance elements (19a), (19b), (19c), and (19d) are connected to the electric circuit board (11) in this way, With the lid (13), the opening of the housing (9) is closed, and the flange (9a) and the lid (13) are welded.

  Thereby, the capsule-shaped sensor (3) in which the open end of the housing (9) is sealed with the lid (13) is completed. 1 and 2 show this state. In this state, the operation hole (9d) has not been closed yet. Further, the attachment portion (14) of the lid (13) is in a state of being warped backward.

  Next, how to attach the sensor (3) to the stem arm (8) which is the attachment surface of the stem (7) will be described.

  First, the adhesive (20) is applied to the front surface (13a) of the lid (13), and the front surface (13a) is brought into contact with the outer surface of the stem arm (8) and positioned. Next, the mounting portion (14) that is warped outward is pressed forward, that is, toward the stem arm (8) to return the warpage, and the mounting portion (14) is brought into close contact with the surface of the stem arm (8).

  In this state, spot welding is performed at a predetermined location, and the lid (13) is fixed to the stem arm (8), so that it can be attached to the stem arm (8). The adhesive (20) applied between the lid (13) and the stem arm (8) is completely solidified because the lid (13) and the stem arm (8) are already fixed. It will not move even if it is not.

  Further, the adhesive (20) is pressed by the reaction force of the mounting portion (14) that warps until it hardens, and after the required curing time (about 12 hours) has passed, it is strong. The adhesive strength is demonstrated and the adhesive strength is maintained for a long time.

  Note that the attachment of the attachment portion (14) and the stem arm (8) is not limited to spot welding, and adhesion by an adhesive may be used. In this case, an instantaneous adhesive having an extremely short curing time can be used as an adhesive for bonding the attachment portion (14) and the stem arm (8).

  Since the adhesive strength of the instant adhesive material only needs to be maintained until the adhesive material (20) between the lid (13) and the stem arm (8) is cured, the adhesive strength can be maintained for a long time. Is not required.

Next, attach the external connector (17) of the inspection circuit to the concave hole (15), which is the connector part of the connector (10), and adjust the resistance with the variable resistor (12). Adjust to balance and perform initial setting prior to detection of open / close of manual valve (1).
At this time, the manual valve (1) is kept in a fully closed state by an appropriate fully closed / closed force by a skilled person.

  When this setting is completed, the operation hole (9d) is filled with a resin material (22) and closed to form a completely sealed capsule sensor (3), and the assembly is completed.

  In the manual valve (1) requiring centralized monitoring or external monitoring, the assembly is completed when the external connector (17) for monitoring and measurement is attached to the connector portion of the connector (10).

  In the case of a single-use manual valve (1), usually a suitable protective cap is attached to the connector (10). By attaching the external connector (17) and balancing the bridge circuit by closing the manual valve (1), the unskilled person can perform the same closing operation as the closing force performed by an expert. it can.

  In the structure of the embodiment described above, the front surface (13a) of the lid (13) is brought into contact with the mounting surface of the support ring (7), that is, the surface of the stem arm (8), and the lid (13) When the mounting portion (14) forming the outer periphery is turned back and the mounting portion (13b) is brought into contact with the surface of the stem arm (8) and spot-welded, the front surface of the lid (13) is attached to the stem arm (8 The sensor (3) can be mounted in a state of being in close contact with the surface of

  Since the front surface (13a) of the lid (13) can be deformed according to the shape of the surface of the stem arm (8), it can be securely fixed and attached without deteriorating the sensor accuracy.

FIG. 8 is a longitudinal sectional view similar to FIG. 3 showing another embodiment.
In this embodiment, the lid body 13) is formed in the same thin plate shape as in the above-described embodiment, and (the mounting flange (9a) for attaching the disk-shaped lid body (13) to the housing (9). In this example, the extended portion is used as a mounting portion (14A) of the housing (9).

  In this case, both the lid (13) and the housing (9) are made of a metal material, the diameter of the lid (13) is increased to be substantially equal to the diameter of the flange (9a), and the mounting portion (14A) is formed. The two-layer structure may be used, or the diameter of the lid (13) may be made large enough to close the opening of the housing (9), and only the flange (9a) may be used as the mounting portion (14A). In either case, spot welding can be performed on the stem arm (8) forming the measurement site.

FIG. 9 shows an embodiment in which the mounting portion (14B) in the embodiment of FIG. 8 is discontinuous in the circumferential direction.
The purpose of the mounting portion (14B) is not to fix the housing (9) to the measurement site for a long time and to seal the inside of the housing (9), but to cover the front surface of the lid (13). The purpose is to press contact the adhesive until the adhesive (20) is solidified.

  For this reason, in order to press the center part in a well-balanced manner to the part to be measured, the protrusions are discontinuously arranged in the circumferential direction so as to form four legs or three legs which are not shown in the figure as shown in the embodiment example. It can also be formed.

  10 and 11 show an example in which the thin plate-like lid (13) is a rubber-like elastic resin lid (13A).

  As in FIG. 8, the housing (9) has a flange (9a) and a mounting portion (14A) at the open end, and the thin plate-like lid (shown in FIG. 8) at the open end of the housing (9). Similar to 13), temporarily fix the temporary lid member (24).

  At that time, only the strain gauge (A) from which the gauge base (18) is omitted is fixed to the rear surface of the temporary lid member (24) easily.

  After that, an elastic resin material having an appropriate hardness after curing, such as silicon resin used for the gap filling material, easy to be deformed, and exhibiting elasticity with high complementarity is provided in the front opening of the housing (9). Filling and curing the elastic resin agent to form a lid (13A) in the opening of the housing (9), omitting the temporary lid member (24).

  A strain gauge (A) is fixed in front of the lid (13A) formed in this way.

  FIG. 11 shows a state in which the housing (9) is attached to the stem arm (8) with the adhesive (20) sandwiched between the front surfaces of the strain gauge (A).

  In this embodiment, even when the surface of the stem arm (8) forming the surface to be measured forms an irregular plane, the portion of the strain gauge (A) is supported by the elastic lid (13A). Therefore, the strain gauge (A) is bonded in a state where it is aligned with the inclination of the measurement surface regardless of the inclination of the casing (9).

  Various modifications and changes can be made to the above embodiment without departing from the scope of the present invention.

It is a principal part notched side view of the manual valve which shows the state which attached the sensor which concerns on 1st Embodiment in this invention. It is an external appearance perspective view of the sensor shown in the state before attaching to a manual valve. FIG. 3 is an enlarged longitudinal sectional side view taken along line III-III in FIG. 2. FIG. 4 is a longitudinal side view similar to FIG. 3 after being attached to a manual valve. It is a figure which shows the arrangement configuration of the resistive element in a strain gauge. It is a circuit diagram which shows the electrical connection state of a strain gauge. It is another circuit diagram which shows the electrical connection state of a strain gauge. It is a center longitudinal cross-sectional view similar to FIG. 3 which shows 2nd Embodiment in this invention. It is a rear view of a sensor which shows a 3rd embodiment in the present invention. It is a center longitudinal cross-sectional view similar to FIG. 3 which shows the 4th Embodiment in this invention. FIG. 11 is a longitudinal sectional view similar to FIG. 2, showing a state where the sensor of the embodiment of FIG. 10 is attached to a manual valve.

Explanation of symbols

(1) Manual valve
(2) Valve stem
(3) Sensor
(4) Valve box
(5) Male thread
(6) Stem nut
(7) Support ring
(8) Stem arm
(9) Housing
(9a) Flange
(9b) Bottom wall
(9c) Hole with flange
(9d) Operation hole
(10) Connector
(10a) Positioning rod
(10b) Screw shaft
(11) Electric circuit board
(12) Variable resistor
(12a) Rotating shaft
(12b) Groove
(13) (13A) Lid
(13a) Front
(14) Mounting part
(15) Recessed hole
(16) Terminal
(17) External connector
(18) Gauge base
(19a) Resistance element
(19b) Resistance element
(19c) Resistance element
(19d) Resistance element
(20) Adhesive
(21) Lead wire
(22) Resin material
(23) Insulation cover
(24) Temporary lid member
(A) Strain gauge
(P1) Spot welding location

Claims (18)

A housing having an open at least one side end of the hollow chamber;
A lid that tightly closes the open end of the housing;
A strain gauge secured to the front or rear surface of the lid,
A strain gauge connection wiring end provided in the housing;
Provided on the outer periphery of the opening of the housing, and having an attachment portion for fixing the housing to the member to be measured while sandwiching an adhesive on the front surface of the lid and pressurizing the lid to the portion to be measured. A strain measurement sensor characterized by comprising:   The strain measurement sensor according to claim 1, wherein the housing is a bottomed cylindrical body having an open end.   The strain measuring sensor according to claim 1 or 2, wherein the lid is a plate member stretched in an eardrum shape at the opening end of the bottomed cylindrical body.   The strain measurement sensor according to claim 1 or 2, wherein the lid is an elastic resin material filled in the front end of the housing so as to close the open end of the bottomed cylindrical body.   The strain measurement sensor according to any one of claims 1 to 4, wherein the lid is fixed to the housing with the center portion slightly convex forward.   The strain measurement sensor according to any one of claims 1 to 5, wherein the strain gauge is a single strain gauge in which four strain detection resistance patterns arranged with a complementary strain detection direction are used as a bridge circuit.   6. The strain gauge according to any one of claims 1 to 5, wherein four strain gauges are disposed so as to complementarily reduce a disturbance component with respect to a strain detection direction when the bridge circuit is configured. The strain measuring sensor described.   The strain measurement sensor according to any one of claims 1 to 7, wherein the strain gauge connection wiring end is a connector connected to the strain gauge so that a balanced output of the bridge circuit can be detected.   The strain measurement sensor according to claim 5, wherein the bridge circuit includes a variable resistor for adjusting the balance of the bridge circuit provided in the housing.   The strain measurement sensor according to any one of claims 1 to 9, wherein the attachment portion extends a part of the lid and protrudes to the outer periphery of the housing.   The strain measurement sensor according to claim 1, wherein the attachment portion is an extension portion of a lid attachment flange provided at an opening end portion of the housing.   The mounting portion extends outward from the outer periphery of the front opening of the housing along the opening surface, and the extended distal end side is warped obliquely toward the rear of the housing. The distortion measuring sensor according to any one of the above.   The strain measurement sensor according to any one of claims 1 to 12, wherein the attachment portion is discontinuous in the circumferential direction. A housing having an open at least one side end of the hollow chamber;
A lid that tightly closes the open end of the housing;
A plurality of strain gauges fixed to the front surface or the rear surface of the lid body to form a bridge circuit;
In order to measure the equilibrium state of the bridge circuit by the plurality of strain gauges, a connection wiring end connected to the bridge circuit,
An attachment portion that is provided on the outer periphery of the opening of the housing, and that attaches the housing to the stem arm while crimping the central portion of the lid to the stem arm of the valve to be measured with an adhesive interposed therebetween;
A bridge circuit provided in the housing, wherein the mounting portion is attached to the stem arm, and then the valve to be measured is either fully open or fully closed to adjust the equilibrium of the bridge circuit at the connection wiring end. A valve opening / closing detection sensor comprising an adjusting means.   The valve opening / closing detection sensor according to claim 14, wherein either or both of the housing and the lid are formed of a metal material, and either or both of the metal materials are projected to the outer periphery of the housing.   The valve opening / closing detection sensor according to claim 14, wherein the attachment portion is fixed to the stem arm by spot welding.   The valve opening / closing detection sensor according to any one of claims 13 to 16, wherein the attachment portion is fixed to the stem arm by an adhesive.   18. The valve opening / closing detection sensor according to claim 17, wherein the adhesive is an adhesive having a faster curing speed than an adhesive that fixes the lid to the stem arm.

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