JPS6150384A - Manufacture of heat flow sensor - Google Patents

Abstract

PURPOSE:To obtain the heat flow sensor of good finish without warp and distortion by molding it after incorporating the bending-prodessed differential thermocouples in a heat-resistant plate of rubber in semi-vulcanized state. CONSTITUTION:A heat-resistant rubber plate of the predetermined thickness and of semi-vulcanized state is made from raw rubber. The semi-vulcanized heat- resistant plate material thus obtained is cut in the approximately same shape and size as of when it is finished as a sensor. And the bent differential thermocouple 23 previously prepared are incorporated in the heat-resistant plate 10. The substance thus obtained is brought in pressure-tight contact by pressing. Then leading wires are connected to the 23 and a thermometer 25 and a sheet 17 made of the same material as of the heat-resistant plate which becomes a coating member is arranged on the front and back surfaces of the combined body of the differential thermocouples and the semi-vulcanized heat-resistant plate. After the pressure and heating molding, heating is made in a heater for a few hours in order to stabilize the vulcanization.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for manufacturing a heat flow sensor. This heat flow sensor is used by attaching a plate to the surface of an object or embedding it inside the object so that the sensor surface is oriented directly in the direction of heat movement. The temperature difference between the back surfaces is detected and the heat flow density [unit: W/m', or in conventional units: kcal/
(m'・h)), where the thermal resistance of the thermal resistance plate is R1 and the temperature difference between the front and back surfaces is ΔT, the heat passing through the heat flow sensor is R(+), and since the heat wave density Q to be measured is proportional to Q', Q is determined. .

Conventional technology In recent years, the necessity of not only thermometers but also heat flow meters (heat flow sensors) has been widely recognized for energy conservation and important thermal management research. However, heat flow sensors are currently more expensive than thermometers. In order to reduce costs, the inventors have successfully mass-produced thermocouple groups, which are the main part of heat flow sensors, at low cost, and have already filed a patent application [Japanese Patent Laid-Open No. 50-158534, Japanese Patent No. 1180193]. No., Utility Model Registration No. 1353777
68B), Utility Model Registration No. 1353778 (Sho 5O-179887)) In these patents, etc., a group of metal wires that are arranged in a state where they can be easily separated is created for each type of dissimilar metal foil for thermocouples. A flat differential thermocouple group is prepared by stacking and joining the ends of the two ends, and a fully vulcanized rubber heat resistance plate and covering material are separately prepared to form a differential thermocouple. After the groups were placed on the front and back sides of the heat resistance plate, the heat resistance plate, the differential thermocouple group, and the covering material were bonded together using an adhesive under pressure. It is true that the differential thermocouple group was convenient because it could be prepared easily and inexpensively, but in the bonding process, it took about a day for the adhesive to harden, and the adhesive flowed onto the surface of the heat flow sensor. When the heat flow sensor is completed, it becomes dirty and loses its commercial value, and when it is completed, the heat flow sensor may not be parallel to each other and may have warps or distortions. .

Therefore, in this production method, a crosslinked polymer resin (thermoplastic resin) or a crosslinked polymer resin that is not completely cured but is partially cured.

Semi-vulcanized rubber is used for the heat resistance plate, and the coating material is the same as the heat resistance plate, and is either uncrosslinked, semi-crosslinked, unvulcanized, or semi-vulcanized, and the coating material and The contact group and the differential thermocouple group, whose entire length is bent simultaneously so that the cold contact group is placed on the front and back surfaces of the heat resistance plate, are molded by pressure heating for several tens of minutes. in,
In addition, we succeeded in obtaining a heat flow sensor with parallel surfaces that is inexpensive, has a good finish, and has no adhesive or other joints. especially,
Warpage or distortion of the heat flow sensor makes it difficult to meet the conditions of close contact with the surface to be measured and causes measurement errors, so a true flat sensor is desirable.

A conventional method for manufacturing a heat flow sensor will be described, and then the method and advantages of the present invention will be described in detail.

FIG. 2 shows the conventional manufacturing method of this type of heat flow sensor, which is the most principled and straightforward method. Heat and flow sensors make holes in a heat resistance plate and pass metal wires through them one after another to create cold and hot junctions. Although it was time consuming, the thermocouple group was completed and the assembly into the heat resistance plate was also completed. In the molding method, the heat resistance plate is made of unvulcanized rubber or uncrosslinked plastic, and both sides are coated with the same material as the heat resistance plate (unvulcanized or uncrosslinked). condition) and then finish it into a heat flow sensor using a hot press. In addition, in the adhesive method, both the heat resistance plate and the covering material are made of a completely crosslinked resin plate or a completely vulcanized rubber,
The heat resistance plate and the covering material are bonded with adhesive.

, 2- Figure 10 illustrates the conventional method.
Drill two rows of holes 2, 1 in the hole, and insert a short wire 4.5 of different metal into each hole.
were passed through and connected on the front and back sides of plate 1 to create cold and hot junctions 6.7. In Japanese Patent No. 1180193, the inventors abandoned the method of manufacturing thermocouple groups by combining them with thermal resistance plates 1, and instead adopted a method of mass-producing only thermocouple groups.

That is, as shown in FIG. 3, 12 groups of metal wires are formed by photo-etching, die-cutting, etc. to be arranged in a manner that they can be easily separated from the thermocouple metal foil 11. Also, although the figure is omitted, the third
The 12 groups of metal wire rods shown in the figure are made upside down using a different type of metal foil than Metal Foil II. These two metal foils are overlapped and the corresponding ends of the wires are joined together (welding, brazing, pressure welding, etc.) to form a thermocouple with cold and hot junctions 13 and 14 arranged on the left and right as shown in Figure 4. Group 15 and remove the outer metal foil frame.

Figures 5 and 6 are examples of another differential thermocouple group, and a wire group is made in such a manner that when the dissimilar metal foils 21 and 22 are stacked and bonded, the thermocouple group 23 in Figure 7 is obtained. . The connecting portion between the frame and the wire rod is schematically indicated by a thin line. In this case, the thermocouple group consists of two groups connected in series. In the bonding method proposed earlier, the thermocouple group 15 in FIG.

As shown in Fig. 8, a long and narrow heat resistance plate IO is bent into a U-shape along one edge, a dummy plate 16 is attached to both sides, the front and back sides are covered with a rubber plate 17, and an adhesive is used. Figure 9 (a)
The exterior was finished as shown. Alternatively, arrange the thermocouple group so that it has the external finish shown in Figure 9 (b).
1llk! SL! -11--117. a. ,Ta. Regarding the thermocouple group 23 in FIG. 7, the metal wire 12 is applied to the inner edge of the heat resistance plate 10 as shown in FIG.
As shown in Figure (B), the thermocouple group 23 was bent and bonded with adhesive.

C6 Problems to be Solved by the Invention However, in the above-mentioned adhesive finishing method, there are disadvantages such as it takes several tens of hours to bond, the finished product is not very clean, and the heat flow sensor is warped or distorted. There were many cases where problems occurred.

On the other hand, when trying to mold a heat flow sensor using the four groups of differential thermoelectrics shown in FIGS. If plastic is used as a thermal resistance plate, the differential thermocouple group will be distorted or bent during pressure heating, and it is a product that the hot junction group and cold junction group are located in the desired situation, and as a result, the temperature decreases. Contacts and cold junctions may penetrate through the covering material and protrude above the sensor surface, or may penetrate into the thermal resistance plate.
The detection sensitivity of the heat flow sensor may not be obtained as a desired value, or the sensitivity may vary widely, which is inconvenient in practice.

20 Means for Solving the Problems The present invention is directed to a manufacturing method for obtaining a desired practical and inexpensive heat flow sensor using a molding method. The materials used for heat resistance plates and covering materials include rubbers such as silicone rubber, neoprene rubber, and fluororubber, and thermosetting plastics.

First, a group of metal materials is made from dissimilar metal foils by photo-etching or die cutting, and the ends of the two are overlapped to form a group of hot junctions and a group of cold junctions, as shown in the examples shown in Figures 4 and 7. Create a flat differential thermocouple group.

Next, the manufacturing process will be explained using as an example a differential thermocouple group shown in FIG. 7, and a heat flow sensor using silicone rubber for the heat resistance plate and coating material.

Rubber to be used as a heat resistance plate is made from raw rubber to a predetermined thickness, for example, 1 mm, and is in a semi-vulcanized state, that is, when the vulcanization temperature is 1 of the vulcanization temperature x vulcanization time during molding.
If the vulcanization time is 70°C, the temperature is 150 to 170°C, and if the vulcanization time is 30 minutes, the vulcanization time is 5 to 15 minutes.
Heat and press (approximately 5 to 20 kg/crn') to produce a semi-vulcanized heat resistant rubber plate. The semi-vulcanized state production method is carried out at a temperature lower than the moldability temperature, but if the temperature is too low, a state between unvulcanized and semi-vulcanized is likely to occur.
While it becomes difficult to stably fix the differential thermocouple group during molding, which will be described later, if the temperature and vulcanization time get close to the molding conditions and vulcanization progresses too much, it may be necessary to cover it with the coating material described later for finishing. Since self-adhesive performance cannot be achieved even with pressure and heating, it is necessary to determine the semi-vulcanization conditions appropriately according to the material of the rubber.

The semi-vulcanized heat resistance plate material obtained as described above is cut out in a state close to the same shape and size as when finished as a sensor. An example is shown in FIG. ■◎○ indicates that the differential thermocouple group in FIG. 7 is cut or separated so that it can be arranged in the state of O or ■. ■◎Other incisions and separations other than O can be considered.

Next, only the planar differential thermocouple group prepared as shown in Fig. 7 was assembled using a press mold or bending metal fittings, as shown in Fig. 11@
Or, bend the entire length all at once so that it has the shape of ω. Then, the bent differential thermocouple group prepared as shown in FIG. 1 is assembled into the thermal resistance plate shown in FIG. 11 ◎ θ. At this time, if necessary, the thermometer 25 in FIG. 7 (the figure shows the wire on one side of the thermocouple) is completed. Then, it is arranged on a thermal resistance plate together with the differential thermocouple group. The reason for this is that the output characteristics of the differential thermocouple group are temperature dependent, and the thermal conductivity of the thermal resistance plate is temperature dependent. This is because it is necessary.

The cross-sectional state incorporated as described above is O or e in Fig. 11.
The integral piece obtained as above is pressed into close contact with a press. This process adapts the differential thermocouple group to the thermal resistance plate,
This is an important step in order to stably fix the differential thermocouple group at a desired position in the pressurized and heated molding step, which will be described later. Then, lead wires are connected to the differential thermocouple groups 23 and 25.

As the final step, sheets made of the same material as the heat resistance plate, which will serve as the covering material, are placed on the front and back surfaces of the combination of the differential thermocouple group and the semi-vulcanized heat resistance plate. This sheet may be in an unvulcanized state or a semi-vulcanized state.

As in the case of the heat resistance plate shown in FIG. 11, the shape and dimensions of the covering material are prepared to be approximately the same as the shape when finished as a heat flow sensor. However, no incision is necessary. And the twelfth
As shown in the figure, the coating material + thermal resistance plate + differential thermocouple group (and thermometer if necessary) are inserted into a spacer cut out in the shape of a sensor, and the coating material is placed in a heating press. At this time, the sum of the initial thicknesses of the coating material + thermal resistance plate + differential thermocouple group + coating material is 0.5% less than the thickness of the spacer.
It is necessary that the thickness be approximately 1 mw.

When pressurizing and heating molding, perform sufficient degassing and meet the specified molding conditions, such as heating at 170°C for 30 minutes and press pressure 5.
Mold at ~20 kg/crn'.

E. By the above-described embodiment, a practical and inexpensive heat flow sensor can be obtained. Then, if necessary, the heat flow sensor taken out from the spacer is heated in a heating furnace at 250° C. for several hours to stabilize vulcanization, which is called secondary curing.

Thereafter, the side-flowing rubber of the sensor (rubber that escaped into the rubber escape hole in Fig. 12) is cut off and molded to complete the sensor.

Under the above molding conditions, the differential thermocouple group is 38 pairs of Chronoru Alumel, and the thickness of the thermal resistance plate of #thermal silicone rubber is L.
++m, overall thickness approximately 3°, width 50+am, thickness of the long rectangular part) loOsm+ heat flow sensor when detected by a heat flow sensor detection device with a 5mm iron plate on the surface that can generate a known heat flow density. The inverse of the sensitivity of a
A is when the sensor temperature is 160℃.A = 173kcal
/(rrr' ・h * mV), A = at 240 °C
It was 187 kcal/(m'-he mV).

The reciprocal A of the sensor's sensitivity does not match the calculated value.

It was a good result.

9. Effects of the Invention As described above, a heat flow sensor that has desired performance and is manufactured at low cost was obtained. If the material is rubber, it can be manufactured using a process similar to the manufacturing method described above. Furthermore, this manufacturing method can be similarly used for thermosetting plastics.

It is important to use a semi-vulcanized or semi-crosslinked heat resistance plate and to blend the heat resistance plate and the differential thermocouple group together by applying pressure, and a good heat flow sensor can be obtained through this process. .

[Brief explanation of the drawing]

FIG. 1 is a drawing showing the main features of the present invention. However, since the present invention consists of a combination of several steps, this figure is not the only main part. Figure 2 is a conventional manufacturing method for a heat flow sensor. Figure 3 is a diagram of the relationship between thermocouple metal foil and metal wire. FIG. 7 is a diagram showing another example of a pair group. FIG. 7 is a configuration diagram of a thermocouple group. FIG. 11 is an explanatory diagram of adhesive finishing. FIG. .

Claims (1)

[Scope of Claims] A. For each dissimilar metal foil for thermocouples, a group of metal wires arranged in a state where they can be easily separated is made, and the corresponding ends of the two are overlapped and joined to form an integrated planar differential thermocouple. In the step of forming the pair group, the hot junction group and the cold junction group are placed on the front and back surfaces of the thermal resistance plate, respectively, at intermediate positions between the left and right cold and hot junction groups of the planar differential thermocouple group. Step 3: The hot junction and cold junction of the differential thermocouple group bent over the entire length are placed on the front and back surfaces of the heat resistance plate prepared in a semi-crosslinked or semi-vulcanized state, respectively. Step (2) of placing the differential thermocouple group in combination with the thermal resistance plate as if it were to be placed, pressurizing it, and molding the differential thermocouple group in close contact with the thermal resistance plate; A thin plate-like covering material of the same quality as the heat resistance plate is placed on the front and back sides of the combination in an uncrosslinked or unvulcanized state, or in a semi-crosslinked or semi-vulcanized state, and is molded using a hot press. A method for manufacturing a heat flow sensor characterized by