JP3027157B1 - Sensor - Google Patents

Abstract

A temperature sensor is incorporated in a sensor case having a built-in ultrasonic sensor so that a single sensor can measure the temperature simultaneously with the axial force of a fastening bolt. SOLUTION: An annular front plate 1 in which a through hole 16 is formed in the center of an opening of a sensor case 14 whose one end is open.
5 is fixed so as to close the opening, a piezoelectric element 17 formed in an annular shape is attached to the inner surface of the front plate 15, and a temperature is inserted into a through hole 16 formed in the front plate 15. The protective frame 18 surrounding the sensor inside was fitted into the sensor, and the position was fixed so that the outer end surface of the protective frame 18 and the outer surface of the front plate 15 were flush.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor used for measuring both the axial force and the temperature of a fastening bolt, and more particularly to a sensor case in which a temperature sensor is also incorporated in a sensor case containing an ultrasonic sensor. The present invention relates to a sensor capable of measuring a temperature simultaneously with an axial force of a fastening bolt.

[0002]

2. Description of the Related Art It is well known to measure, for example, the axial force of a fastening bolt using an ultrasonic sensor. The measured value of the axial force changed with the temperature change, and it was impossible to measure an accurate axial force. Therefore, in order to increase the measurement accuracy of the axial force measurement value using the ultrasonic sensor, conventionally, as shown in FIG. 2, the ultrasonic sensor 2 is supported in contact with the head of the fastening bolt 1 which is the object to be measured. It is known that the temperature sensor 3 is individually abutted and supported on the side surface of the head, and the ultrasonic sensor 2 and the temperature sensor 3 are used together to detect the axial force of the fastening bolt 1.

[0003]

However, conventionally, since the ultrasonic sensor 2 and the temperature sensor are separate bodies,
In addition to the work of attaching the ultrasonic sensor to the fastening bolt 1, the work of attaching the temperature sensor 3 must be performed individually.
The installation work of the ultrasonic sensor 2 and the temperature sensor 3 is troublesome. When the fastening bolt 1 is small, or when the head of the fastening bolt 1 is inserted into the recess 5 of the body 4 to be fastened, the upper surface of the fastening bolt 1 together with the ultrasonic sensor is placed on the upper surface of the fastening bolt 1. Although it is possible to position
It is difficult to support the temperature sensor 3 on the side of the head of the bolt 1, and there is a problem that it is impossible to set both the ultrasonic sensor and the temperature sensor on the same bolt 1.

The present invention has been made in view of such a conventional problem. A temperature sensor is provided inside an ultrasonic sensor case having a built-in ultrasonic sensor, a vibration receiving surface of the ultrasonic sensor, and a temperature sensor. It is an object of the present invention to provide a sensor in which the temperature sensing surface is provided on the same surface and the temperature of the fastening screw can be measured together with the vibration receiving surface of the ultrasonic case.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, an annular front plate having a through hole formed at the center in an opening of a sensor case having an open end. Is fixed so that the opening is closed, a ring-shaped piezoelectric element is attached to the inner surface of the front plate, and a temperature sensor is internally enclosed in a through hole formed in the front plate. And a positionally fixed sensor such that the outer end surface of the protective frame and the outer surface of the front plate are flush with each other.

According to a second aspect of the present invention, in addition to the first aspect, a sensor in which the front plate is formed of a material having abrasion resistance and the protective frame is formed of a material having a high thermal conductivity. It is characterized by being.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in FIG.

Reference numeral 11 denotes a bolt which is a fastening screw whose axial force is to be measured, and reference numeral 12 denotes an end face of the head of the bolt 11. Reference numeral 13 denotes a sensor used to measure the axial force and temperature of the bolt 11 fastened to a body (not shown). Hereinafter, the configuration of the sensor 13 will be specifically described.

Reference numeral 14 denotes a cylindrical sensor case having an opening only at the lower end face. The material of the sensor case 14 may be a metal, resin or the like having rigidity as the case. Reference numeral 15 denotes a front plate which is positioned so as to close the opening of the sensor case 14.
The front plate 15 is formed in an annular shape with a through hole 16 formed in the center thereof. As the material of the front plate 15, for example, as shown in Table 1, a metal having wear resistance (for example, alumina oxide, aluminum nitride, or the like) can be selected and used. 1
Reference numeral 7 denotes a ring-shaped piezoelectric element adhered to the inner surface of the front plate 15 so as to avoid the through holes 16. Reference numeral 18 denotes a protective frame which is closely fitted to the through hole 16 formed in the front plate 15, and the shape of the protective frame 18 has a bottomed bottom so that a temperature sensor 19 can be housed therein. It is formed in a container shape. As shown in Table 1, the material of the protective frame 18 can be selected from those having high thermal conductivity, such as solder, oxygen-free copper, and pure aluminum. The bottom outer surface of the protective frame 18 tightly fitted in the through hole 16 of the front plate 15 and the outer surface of the front plate 15 are formed so as to be flush with each other. It is formed so as to be able to make accurate surface contact with the end surface 12.

Reference numerals 20 and 21 denote connectors mounted on the sensor case 14. The connector 20 is connected to the piezoelectric element 17 via a lead wire 22, and the connector 21 is connected to the temperature via a lead wire 23. It is connected to a sensor 19. Reference numeral 24 denotes a molding material that is filled in the internal space of the sensor case 14.
Is excellent in insulation, and the front plate 15 and the protective frame 1
For example, epoxy resin, which is excellent in fixing stability between the sensor case 8 and the sensor case 14, can be used.

The connectors 20 and 21 are connected to an ultrasonic axial force meter and a thermometer (not shown).

[0012]

[Table 1]

The operation of the present embodiment has been described above. Next, the operation will be described. The ultrasonic sensor 13 is located at the center of the ring-shaped piezoelectric element 17 and the center of the ring-shaped piezoelectric element 17. And a piezoelectric sensor 1 having a temperature sensor 19.
7 is closely attached to the front plate 15 and the temperature sensor 1
9 is closely attached to the protection frame 18.

When the sensor 13 is used to position the front plate 15 of the sensor 13 in contact with the head end surface 12 of the bolt 11 whose axial force and temperature are to be measured, the piezoelectric element 17 in the sensor case 14 The bolt is indirectly abutted to the head end face 12 through a wear-resistant front plate 15, and the temperature sensor 19 in the sensor case 14 is connected via a bottom wall of a protective frame 18 having excellent thermal conductivity. And is indirectly abutted against the head end surface 12 of the bolt.

As described above, the sensor case 14 is
By positioning it on the head end face 12 of the
Can be detected by the piezoelectric element 17 via the front plate 15, and at the same time, the temperature of the bolt 11 can be detected by the temperature sensor 19 via the protective frame 18. Accordingly, by placing the sensor case 14 of the sensor 13 as a single body in contact with the head end face 12 of the bolt, both the piezoelectric element 17 and the temperature sensor 19 are indirectly positioned on the head end face 12 of the bolt. Thus, the work of setting the piezoelectric element 17 and the temperature sensor 19 to the bolt 11 can be performed smoothly and easily.

As described above, since the piezoelectric element 17 housed in the sensor case 14 is protected by the front plate 11 having a high hardness and abrasion resistance, the piezoelectric element 17 is prevented from being damaged. The axial force of the bolt 11 can be measured while doing so. Further, since the temperature sensor 19 contained in the sensor case 14 is protected by the protective frame 18, it is obvious that the temperature sensor 19 can be prevented from being damaged. Since it is made of a material having a high temperature, the axial force accompanying the temperature change of the bolt 11 can be measured quickly and accurately.

[0017]

As described above, according to the ultrasonic sensor of the first aspect of the present invention, the piezoelectric element 17 and the temperature sensor 19 are moved by operating the sensor case 14 having a single structure.
Can be positioned on the head end surface 12 of the bolt 11 so that the operation of setting the piezoelectric element 17 and the temperature sensor 19 to the bolt whose axial force and temperature are to be measured can be performed easily and quickly, and Damage to the element 17 and the temperature sensor 19 can be prevented beforehand, and an ultrasonic sensor excellent in durability and reliability can be obtained.

According to the ultrasonic sensor of the second aspect of the present invention, the axial force and the temperature of the bolt 11 are controlled by the piezoelectric element 17.
In addition, the transmission accuracy and the speed of transmission for transmitting the temperature to the temperature sensor 19 are improved, and the axial force value accompanying the temperature change of the bolt can be measured quickly and accurately.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an embodiment of a sensor according to the present invention.

FIG. 2 is an explanatory view showing attachment of a conventional ultrasonic sensor and a temperature sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Bolt 12 ... Head end surface 13 ... Sensor 14 ... Sensor case 15 ... Front plate 16 ... Through-hole 17 ... Piezoelectric element 18 ... Protection frame 19 ... Temperature sensor 20 ... Connector 21 ... Connector 22 ... Lead wire 23 ... Lead wire 24 … Mold material

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Claims (2)

(57) [Claims] 1. A sensor case (14) having an open end.
An annular front plate (15) having a through hole (16) formed in the center is fixed to the opening so as to close the opening, and is formed in an annular shape on the inner surface of the front plate (15). The protection element (18) surrounding the temperature sensor is fitted into a through hole (16) formed in the front plate (15). A sensor characterized in that the position is fixed so that the outer end surface of the frame (18) and the outer surface of the front plate (15) are flush with each other. 2. The method according to claim 1, wherein the front plate is formed of a material having wear resistance, and the protective frame is formed of a material having high thermal conductivity. The sensor as described.