JP3075045B2 - Temperature sensor and temperature measurement structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature sensor and a temperature measuring structure, and more particularly to a temperature sensor suitable for measuring the temperature of a viscous fluid or a resin molded product, and an improvement of the temperature measuring structure using the same.

[0002]

2. Description of the Related Art Conventionally, as a temperature sensor of this kind,
There are a thermal expansion type, a thermocouple type, a resistance type, a heat radiation type and the like, but a thermocouple type or a resistance type is frequently used because of its simple structure and low cost. Are as shown in FIG. In this configuration, a thermocouple wire 3 is inserted into a thin protective tube 1 made of stainless steel whose end is closed, and its distal end 5 is connected to the inside of the distal end of the protective tube 1. This protective tube 1 is made of metal. It is supported by a molding die 7 (only a part of which is shown), and its tip is made to protrude into the cavity 9 of the molding die 7, and heat from the molten resin 11, which is a temperature measuring object, is passed through the protective tube 1 through a thermocouple. The sheath 3 is of a so-called sheath type in which the wire 3 receives heat and detects the temperature while preventing the load pressure and the fluid from being applied to the thermocouple 3 from the molten resin 11 by the protective tube 1.

However, in this configuration, since the protective tube 1 having a large thermal conductivity is supported by the molding die 7, the amount of heat leaking to the molding die 7 through the protective tube 1 is large, and the temperature can be accurately measured. In order to achieve this, the protection tube 1
Therefore, it is necessary to increase the outer diameter of the protective tube 1 or increase the protruding length to increase the contact area between the molten resin 11 and the protective tube 1. For example, when the protective tube 1 having an outer diameter of about 1 mm is used, it is necessary to protrude the protective tube 1 by more than 10 mm from the molding die 7. Therefore, the protective tube 1 is easily bent by the resin pressure of the molten resin 11, and the molding die 7 for molding a sheet-like thin molded product has a flat cavity 9 so that the tip of the protective tube 1 faces the molding die. There were drawbacks, such as being unable to be used due to collision with the seven portions, and the traces of the protective tube 1 becoming holes after the solidification of the resin molded product, and tending to remain.

[0004] In order to solve such a drawback, a temperature sensor as shown in FIG. 3 has also been proposed. That is,
Heat-receiving plate 1 made of stainless steel at the open end of thin protective tube 13
5, the distal end 19 of the thermocouple wire 17 inserted into the protective tube 13 is connected to the back surface of the heat receiving plate 15, and the outer surface of the heat receiving plate 15 is formed in a cavity of a molding die 21 (only a part is shown). Face 2
3, the protective tube 13 is fixed to the molding die 21 together with the heat receiving plate 15 so that the cavity surface 23 is flat and the heat receiving area is not reduced.

[0005]

However, in the configuration of FIG. 3 described above, since the periphery of the heat receiving plate 15 is in contact with the molding die 21, the disadvantage that the amount of leaked heat is still large remains, and the heat capacity is particularly small. It has been difficult to accurately measure the temperature of a liquid (not shown in FIG. 3) such as a molten resin or oil that changes rapidly. The present invention has been made in order to solve the above-mentioned drawbacks, and a flat contact surface has been obtained with respect to a temperature measuring object such as a molten resin. It is intended to provide a temperature sensor and a temperature measurement structure.

[0006]

In order to solve the above-mentioned problems, a temperature sensor according to the present invention comprises a metal heat-receiving plate in contact with a temperature measuring object, and an inorganic material having a lower thermal conductivity than the heat-receiving plate. A holder having a through hole from which the heat receiving plate is supported and fixed on the contact surface side with the temperature measuring object so as to close the through hole and surround the periphery of the heat receiving plate, and receive the contact surface with heat. It has a holder aligned with that of the plate, and a temperature measuring element connected to the back surface of the heat receiving plate corresponding to the through hole and led out through the through hole.

Further, the temperature measuring structure of the present invention comprises a contact base to be contacted by a temperature measuring object, a metal heat receiving plate in contact with the temperature measuring object, and an inorganic material having a lower thermal conductivity than the heat receiving plate. A holder having a through hole and supported by the contact base, wherein the heat receiving plate is supported and fixed on the contact surface side with the temperature measuring object so as to close the through hole and surround the periphery of the heat receiving plate. A holder, and a temperature measuring element connected to the back surface of the heat receiving plate corresponding to the through hole and drawn out through the through hole, and the heat receiving plate, the holder and the contact base contact the temperature measuring object. The surface is aligned. And
In the temperature sensor and the temperature measurement structure, the heat receiving plate is fixed to the holder with a heat-resistant inorganic adhesive, or a portion of the heat receiving plate and the holder facing the body to be measured with the adhesive is filled with the heat receiving plate. It is preferable to form the gap between the holder and the holder flat.

[0008]

In the temperature sensor according to the present invention provided with such means, the holder for supporting and fixing the heat receiving plate is formed of an inorganic material having a smaller thermal conductivity than that of the heat receiving plate. Since the smaller holder is located, the amount of heat leaking from the heat receiving plate through the holder is suppressed, the temperature change of the temperature measuring object is accurately transmitted to the temperature measuring body, and the contact surface with the temperature measuring object Becomes flat. Further, in the temperature measurement structure according to the present invention, the amount of heat leaking from the heat receiving plate to the contact base via the holder is suppressed, and the temperature change of the temperature measuring object is accurately transmitted to the temperature measuring body. The contact surfaces of the holder and the contact base with the temperature measuring object become flat.

In the temperature sensor and the temperature measurement structure, in the configuration in which the heat receiving plate is fixed to the holder with a heat resistant inorganic adhesive, the heat conductivity of the adhesive is reduced, and the heat receiving plate has sufficient heat resistance and ceramics. Abrasion resistance and strength close to Further, in the configuration in which the space between the heat receiving plate and the holder at the contact surface with the temperature measuring object is filled with the adhesive, even if a gap is generated between the heat receiving plate and the holder from the point of creation, the contact surface with the temperature measuring object is not changed. Become flat.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a temperature sensor and a temperature measuring structure according to the present invention. For convenience, the temperature sensor will be described in the process of explaining the temperature measuring structure.
In FIG. 1, an insertion hole 27 is formed in a movable back plate 25 made of a metal material that forms a normal molding die or the like, and a cylindrical holder 31 having a through hole 29 is inserted into the insertion hole 27. 27 is overlapped on the movable side back plate 25 in a state where the through hole 29 communicates with 27. The holder 31 has a flange 33 formed on the outer periphery of the base in contact with the movable back plate 25, and a distal end surface opposite to the movable back plate 25 (upper side in FIG. 1).
Is formed with a concave groove 35 concentrically surrounding the through hole 29,
A convex portion 37 which is slightly inwardly recessed from the distal end surface opposite to the movable side back plate 25 is formed so as to face the through hole 29.

The through hole 29 of the holder 31 communicates with the same inner diameter as the insertion hole 27 of the movable back plate 25, and has a small diameter in the middle and extends to the tip end surface opposite to the movable back plate 25. A flat circular cap-shaped heat receiving plate 39 is fitted in the concave groove 35 with play, and at least the back surface of the heat receiving plate 39 is supported by the holder 31. The heat receiving plate 39 is not easily deformed by the load pressure of the molten resin 41 described later, and prevents the molten resin 41 from being mixed into the through hole 29. The shape of the heat receiving plate 39 is not limited to the circular cap shape, and may be, for example, a simple flat plate. The heat receiving plate 39 is made of a hard metal material having good thermal conductivity and transmitting a temperature change sensitively, for example, 0.1 mm.
Rockwell hardness (HR)
C) It is formed by bending a stainless steel plate having a hardness of about 60.

The holder 31 for supporting the heat receiving plate 39 is made of a material having a thermal conductivity of at least 0.01 (cal / cm · sec · ° C.) or less than the material of the heat receiving plate 39, such as a machineable material. It is formed by processing an inorganic insulating material such as ceramics, zirconia, glass or quartz. That is, the holder 31 is moved from the heat receiving plate 39.
Has a significantly lower thermal conductivity. A plurality of small holes 45 are formed in the side wall 43 of the heat receiving plate 39 at intervals in the circumferential direction, and the heat receiving plate 39 is formed by the heat resistant adhesive 47 filled in the concave groove 35 of the holder 31. 29 is fixed to the holder 31 so as to close it, and the front end surface of the holder 31 and the outer surface of the heat receiving plate 39 are located on the same plane.

The adhesive 47 is a mounting means made of a liquid or fluid inorganic material which is turned into a ceramic at a predetermined temperature of, for example, 150 ° C. or more. The adhesive 47 also flows through the small holes 45 provided on the side walls 43 of the heat receiving plate 39 to flow therethrough. The support and fixing by the holder 31 of 39 are ensured. Further, the adhesive 47 is filled between the periphery of the holder 31 and the heat receiving plate 39 on the distal end surface side of the holder 31 so as not to generate a gap and to be flat so as not to form irregularities. Insertion hole 27 of movable back plate 25
A protective tube 49 made of stainless steel is inserted halfway into the through hole 29 of the holder 31. A thermocouple wire 51 as a temperature measuring element is inserted into the protective tube 49 and extends to the inner surface of the heat receiving plate 39, and the distal end of the thermocouple wire 51 is welded in a region corresponding to the through hole 29 on the back surface of the heat receiving plate 39. And so on.

Protective tube 49 and insertion hole 2 extending therefrom
The small-diameter portion 7 is filled with an insulating material such as magnesium oxide or alumina powder up to the back surface of the heat receiving plate 39.
As the temperature measuring element, a minute resistor or a thin film resistor other than the thermocouple wire 51 can be used, and the minute resistor or the thin film resistor connected to the back surface of the heat receiving plate 39 can be used. The lead wire is led out through the protection tube 49,
It is also possible to connect to a converter (not shown) or a temperature controller. A movable mold plate 53 is fitted around the holder 31 so as to overlap the movable back plate 25. The movable mold plate 53 is made of a conventionally known metal material for a mold, for example, S
The upper surface in the figure is located on the same plane as the above-mentioned tip surface of the holder 31 and the outer surface of the heat receiving plate 39, and a fixed side die made of a similar metal material or the like. The plates 55 are stacked, and the movable mold plates 53 and 55 form a cavity 57 for resin molding.

However, the cavity surface 59 is formed on the distal end surface of the holder 31 and the outer surface of the heat receiving plate 39 together with the movable mold plates 53 and 55. The holder 31
Is fixed to the movable back plate 25 by ordinary screws (not shown) or special screws called compression fittings (not shown), in addition to the fixing by the movable back plate 25 of the embodiment. Needless to say, there is. In the temperature measurement structure having such a configuration, when the molten resin 41 is poured into the cavity 57, the molten resin 41 is formed into an outer shape according to the shape of the cavity 57, and the heat of the molten resin 41 comes into contact with the molten resin 41. Heat receiving plate 3
The temperature is transmitted to the thermocouple wire 51 via the line 9 and the temperature is measured.

As described above, according to the present invention, the heat receiving plate 3 made of metal is used.
9 is supported and fixed by a holder 31 having a significantly lower thermal conductivity so as to surround the periphery thereof, the through hole 29 of the holder 31 is closed by the heat receiving plate 39, and a thermocouple wire 51 connected to the heat receiving plate 39 is connected. Since the temperature sensor is configured to be led out to the outside through the through hole 29 of the holder 31 and the contact surfaces of the heat receiving plate 39 and the holder 31 with the molten resin 41 are aligned, the periphery of the heat receiving plate 39 having a large thermal conductivity is reduced. Thus, the heat receiving plate 39 is supported so as to be surrounded by the holder 31 having a small thermal conductivity, so that the heat received by the heat receiving plate 39 can be prevented from leaking to surrounding members, and the heat receiving area can be largely maintained. Therefore, the heat is quickly conducted to the thermocouple wire 51 following the temperature change of the molten resin 41, and the temperature measurement of the molten resin 41 having a small heat capacity and a fast temperature change becomes accurate. The flat shape does not hinder the external shape of the molded product, and the structure is simple.

From the viewpoint of minimizing the amount of heat leaked through the holder 31, the thermal conductivity of the holder 31 is one-eighth that of the heat receiving plate 39, preferably about 1 /
It would be better to select a material that is smaller than 10.
Further, in the present invention, the temperature measurement structure is configured by using the above-described temperature sensor and aligning the cavity surface 59 of the movable mold plate 53 with the contact surface between the heat receiving plate 39 and the molten resin 41 of the holder 31. For example, the cavity surface 59 of the movable mold plate 53 becomes flat, and accurate temperature measurement can be performed in a state where the outer shape and quality of the molded product are maintained high. further,
Since the heat receiving plate 39 is fixed to the holder 31 with the heat-resistant adhesive 47, it is possible to measure a high temperature of several hundred degrees Celsius.
Filling the gap and flattening the cavity surface 59 against the molten resin 41
Therefore, the external quality of the molded product can be further improved.

Moreover, the adhesive 47 made of an inorganic material is
High adhesion, low thermal conductivity, heat resistant temperature of 1000 ° C
It has a high degree of thermal expansion close to that of a metal material, and also has good abrasion resistance. Therefore, even when a peeling force of a resin or the like acts on the adhesive 47 when a molded product is taken out, it is difficult to be peeled off.
It is possible to reduce the amount of heat leaked,
When the molten resin 41 containing a glass-containing molding material such as PS (polyphenylene sulfide) is formed, the adhesive 47 is not easily removed by the molten resin 41. Note that the adhesive 47 only needs to have good heat resistance, and if it has a heat resistance of about 300 ° C., it is practically possible to use an organic adhesive such as an epoxy adhesive other than the heat-resistant inorganic material. .
When the holder 31 is formed using machineable ceramics, the outer shape of the holder 31, particularly the corners, can be accurately formed. Therefore, for example, a gap or the like is less likely to be formed at a contact portion between the holder 31 and the movable mold plate 53. There is an advantage that burrs are eliminated from the molded product.

In the above-described embodiment, the temperature sensor of the present invention is incorporated in the movable mold plate 53 to form a temperature measuring structure. However, the present invention is not limited to this. Although not shown,
For example, it is possible to arrange the temperature sensor of the present invention in a cylinder part of an extruder to form a temperature measurement structure. The point is that the temperature sensor holder is fixed to the contact base that contacts the molding resin, the contact surface between the heat receiving plate and the molding resin, the contact surface of the holder that supports the heat receiving plate and contacts the molding resin around it, and the contact The object of the present invention can be achieved if the contact surface of the substrate with the resin is located on the same surface. Further, in the embodiment of the present invention, the present invention can be applied not only to the molten resin but also to the measurement of the temperature of a temperature measuring object such as various fluids and solids. Furthermore, FIG.
The movable mold plate 53 and the fixed mold plate 55 can be implemented by exchanging the movable side and the fixed side.

[0020]

As described above, the temperature sensor of the present invention has a metal heat-receiving plate in contact with a temperature measuring object and a through-hole made of an inorganic material having a thermal conductivity smaller than that of the heat-receiving plate. Having a holder, and supporting and fixing the heat receiving plate with the holder so as to surround the peripheral edge of the heat receiving plate so as to cover the through-hole while contacting the surface with the contact surface of the heat receiving plate with the temperature measuring object. Because the temperature measuring element connected to the back side is configured to be led out from the through hole, the amount of heat leaked from the heat receiving plate decreases, and the temperature change is quickly transmitted to the temperature measuring element. Accurate temperature measurement is possible, the quality of the outer surface of the temperature measuring object can be maintained, and a large heat receiving area can be maintained. Therefore, the present invention is particularly suitable for temperature measurement of a temperature measuring object (measurement object) having a small heat capacity and a rapid temperature change. Further, in the present invention, the temperature measurement structure is configured by fixing and holding the holder of the above-mentioned temperature sensor with the contact base and aligning the contact surfaces of the heat receiving plate, the holder and the contact base with the temperature measuring object on the same plane. In addition, accurate temperature measurement can be performed while maintaining the external surface quality of the temperature measuring object in a contact substrate, for example, a molding die. In the temperature sensor and the temperature measurement structure, in the configuration in which the heat receiving plate is fixed to the holder with a heat-resistant inorganic adhesive, sufficient heat resistance is obtained, and abrasion resistance and strength close to ceramics are obtained. There are advantages. Further, in the configuration in which the space between the heat receiving plate and the holder on the contact surface with the temperature measuring object is filled with the adhesive,
The external surface quality of the temperature measuring object can be further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a temperature sensor and a temperature measurement structure of the present invention.

FIG. 2 is a sectional view showing a conventional temperature sensor.

FIG. 3 is a cross-sectional view showing another configuration of a conventional temperature sensor.

[Explanation of symbols]

 1, 13, 49 Protective tube 3, 17, 51 Thermocouple wire (temperature measuring element) 5, 19 Tip 7, 21 Mold 9, 57 Cavity 11, 41 Molten resin (temperature measuring object) 15, 39 Heat receiving Plates 23, 59 Cavity surface 25 Movable back plate 27 Insertion hole 29 Through hole 31 Holder 33 Flange 35 Recessed groove 37 Convex portion 43 Side wall 45 Small hole 47 Adhesive 53 Movable mold plate (contact base) 55 Fixed mold plate ( Contact substrate)

Claims (6)

(57) [Claims] 1. A holder having a metal heat receiving plate in contact with a temperature measuring object and having a through hole made of an inorganic material having a thermal conductivity smaller than that of the heat receiving plate. A holder configured to support and fix the heat receiving plate on the contact surface side with the temperature measuring object so as to surround the periphery of the heat receiving plate, and to align the contact surface with the contact surface of the heat receiving plate; A temperature sensor connected to the back surface of the heat receiving plate and led out through the through hole. 2. The temperature sensor according to claim 1, wherein the heat receiving plate is fixed to the holder with a heat-resistant inorganic adhesive. 3. The temperature sensor according to claim 2, wherein a portion facing the temperature measuring object between the heat receiving plate and the holder is buried with the adhesive to be formed flat. 4. A contact base with which a temperature measuring object contacts, a metal heat receiving plate contacting with the temperature measuring object, and a through hole formed of an inorganic material having a thermal conductivity smaller than that of the heat receiving plate. A holder supported by the contact base, the holder supporting and fixing the heat receiving plate on the contact surface side with the temperature measuring object so as to close the through hole and surround the periphery of the heat receiving plate; A temperature measuring element connected to the corresponding back surface of the heat receiving plate and led out through the through-hole, and a temperature measuring structure comprising: the heat receiving plate, a holder and a temperature measuring body of a contact base. A temperature measuring structure characterized by having contact surfaces of the same. 5. The temperature measuring structure according to claim 4, wherein the heat receiving plate is fixed to the holder with a heat-resistant inorganic adhesive. 6. The temperature sensor according to claim 5, wherein a portion facing the temperature measuring body between the heat receiving plate and the holder is buried with the adhesive to be formed flat.