JPS5846601A - How to fix resistance wire inside a thin tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes changes in electrical resistance due to temperature changes to maintain a constant temperature of a fluid or an integral body. This method involves fixing and protecting a resistance wire of a flow rate measuring center t-1 or a sheathed heater, which detects a change in resistance and keeps the fluid velocity constant based on the change, in a thin tube.

Conventional types of Fuchi temperature resistors, 7-circuit sensors for gauge ballasts, etc. are made of fine wire (6 to 40 ink) with a large temperature coefficient of resistance, such as tungsten wire, nickel wire, or platinum wire, as a resistance wire. Stones that are used as a spiral bare wire or wrapped around the surface of an insulator are often cut and rendered unusable when used in the bare wire state *b.
On the other hand, those in which resistance wire is wound around the surface of the insulator have an unstable shape, and dust from the fluid adheres to them, making cleaning extremely difficult. Furthermore, in such a tk-toner, it is impossible to maintain a constant flow rate before the temperature of the liquid.

In order to eliminate this drawback, a certain method was implemented in which a heat-sensitive resistor was sealed in a hard tube with an inorganic insulating powder such as magnesia and an insulating organic polymer adhesive. However, with such a filling method, if the inner diameter of the hard chain is minute, it is impossible to fill the bottle with non-powder-free insulating powder, etc.).
-: /f- can be manufactured, but since the circuit itself becomes larger, it takes time for the fluid to be measured and the resistor to reach thermal equilibrium, and the fluctuating temperature of the fluid keeps the flow velocity constant. Moreover, the method of sealing with an organic polymer adhesive has the disadvantage that it cannot withstand high temperatures of about 100° C. or higher.

The present invention eliminates the above-mentioned drawbacks and provides a sensor for ballast instruments (thermal sensitive resistor) or a sheathed heater for high temperatures that is small, has fast response, can reach high temperatures, and can accurately measure temperature or fluid flow velocity. According to the present invention, a resistance wire powder is inserted, the nine capillary tubes are immersed in an aqueous dispersion of ceramic raw powder*, and the resistance wire and other electrode plates are connected. When a voltage is applied to the resistance wire, ceramic particles in an aqueous dispersion are electrodeposited over the entire length of the resistance wire surface using electrophoresis, and then filled into a thin tube and fired. .

An example will be described below with reference to the drawings. As shown in Figure 1, a thin platinum wire with a value of about 0.35111 is wound spirally at both ends of a thin resistor. , jimmy
The platinum leads M(1), (1) are connected by electric bath welding to a ceramic capillary tube (made of alumina or silica or a mixture thereof) with an inner diameter of 0.5 mm and a length of about SO4). , insert the platinum resistance thin wire body so that the welded part between → and the resistance thin wire (2) fits, and fill the container (→) with appropriate holding A(6)K. Suspended and immersed in the silica go-aqueous sol ←), apply a positive voltage to the appropriate DC power source (6), and apply a negative voltage to the electrode (9) provided in the silica sol. When voltage is applied,
When the silica mold particles in the silica sol (4), which are charged with a certain amount of electric charge, are connected to a platinum lead wire ω and a voltage is applied for about 10 minutes, the inside of the ceramic capillary is filled with embedded silica particles (4a), so that electricity is applied. Stop the stop, pull up the ceramic tube (2), electrodeposit nine silica particles (41) in the ceramic tube (2) as shown in Figure 2, and dry.
A slurry-like dispersion obtained by mixing the silica particle mixture attached to the platinum lead wire ←) with approximately three times the volume of water, methyl alcohol, or other suitable volatile wave material is additionally filled as shown at both ends of the capillary tube K (4b). The above dispersion (
4b) Evaporate the moisture in the tube, raise the temperature to about 1200℃ in 6 hours, maintain it at about 1200℃ for 1lcso minutes, and fire the ceramic raw material powder in the ceramic tube to remove air, adsorbed gas, water vapor, etc. Completely expelled and ceramic at both ends of the capillary (
4b) is sintered. After that, the platinum resistance wire is slowly cooled to room temperature over about 10 hours, and the platinum resistance wire is fixed in the sehramic capillary by fired ceramic.

Figures 6 to 6 show other embodiments of the present invention. As shown in Figures 3 and 4, a ceramic cylinder (3a) with three through holes is prepared, and tungsten is Electrically weld the lead wires (1) and (1) to both ends, insert the nine tungsten resistance wires (1) into the two through holes, and attach the ceramic cylinder (3a) to the container with an appropriate holder (6).
) filled with 9 alumina, suspended and immersed in a GoS aqueous sol (4), and connected to a suitable DC power supply (8)] leads, fill
(1) K negative voltage, when a positive voltage is applied to the pole (9) of 1 provided in the alumina sol (4), the alumina sol carrying a positive charge (the alumina fine particles in 4 are lead wires ←) and the resistive thin wire (Electrodeposit mK on the surface of gong.l.

When a 4D voltage is applied for about 10 minutes, the holes in the ceramic cylinder (!a) will be filled with alumina particles, so turn off the current and pull up the ceramic cylinder (5a).
As shown in the figure, the aluminum particles (4a) electrodeposited in the through holes of the ceramic cylinder ([1] are dried, the electrodeposited layer of alumina particles adhering to the lead wire (1) is removed, and then Raku firing is performed. 9 is obtained by mixing a low melting point ceramic such as spinel (MgA1. Fill it and dry it at 80-100℃ for about 1 hour, about 〒ooc in 6 hours.
The alumina sol (4a) is fired by raising the temperature to about 0°C and maintaining the temperature at KIO for 10 minutes, completely expelling air, adsorbed gas, water vapor, etc. in the ceramic tube, and sintering the low melting point ceramic (4b) at both ends. do. After that, let it cool down to room temperature for about 10 hours.
The resistance thin wire (K) is identified by the sintered ceramic 5 (4&) and the sintered ceramic (4b) K in the ceramic tube (3).

In the above embodiments, platinum and tungsten are used as the lead wire (1) and the resistive thin wire body, and the ceramic tube (wire) is made of platinum and tungsten.

Although alumina, silica, etc. were used as (3a), any suitable conductor can be used for the lead wire (ω, resistance wire) as long as it does not cause surface oxidation in the outside air. Aluminum, mullite, or zirconia may be used for sa), and alumina, silica, magnesia, quartz glass, etc., or a mixture thereof may be used for filling powder (4a)*(4b). In addition, it is necessary to select and combine the materials of the ceramic capillary (daughter, filling ceramic powder (4a), and resistance wire) so that the expansion coefficients are as equal as possible), and the electrical resistance due to temperature changes. When used as a sensor for a measuring instrument that utilizes changes in resistance, a conductive wire of platinum, tungsten, nickel, stainless steel, German silver, phosphor bronze, etc., which has a large temperature coefficient of resistance, is used as the resistance wire (2). Of course, the resistance thin wire body is not limited to a spiral shape, and a straight shape may also be used.

Since the present invention is configured as described above, for example,
i0.8mm, inner diameter 0゜5mm, length'! 4111 ceramic thin tube body) and platinum resistance thin wire (rumored diameter 20 ~
50 inches, the length of the spiral part is 3 m1 m1 (resistance 1.0 to 3 ohms), the diameter of the platinum lead wire (1) is O, j
By configuring it at 1-0.4 degrees Celsius, it can be used as a resistance temperature detector to measure accurately in the range of -200 to -200 degrees Celsius and with a response speed of 0.1 to 2 seconds.
Also, if the flow rate of the surrounding fluid is constant due to temperature changes in the sensor, the flow rate will be 0.1 to 50 wh/@e a, approximately 1! (The D flow rate can be kept accurately within ±2-2 and quickly with a response time of about 0.δ seconds, and has excellent impact resistance and heat resistance, and is suitable for active gases, chemicals, etc. in the fluid. If a conductor other than platinum is used as the resistance (1) or lead wire Q), it is limited by its heat resistance, oxidation resistance, and chemical resistance to a constant fluid or its temperature.

As described above, the present invention can fill an extremely small tube with an inorganic insulator at a high density (more than 95 mm), and therefore, a sensor for a nine-hand column instrument manufactured by this method can be used for conventional measuring instruments. It has a very small heat capacity compared to a sensor, so it can measure heat response very quickly and accurately, and has strong physical strength, so it can be used as a resistance temperature detector, a sensor for measuring flow velocity, a resistor for temperature compensation, etc. and 4K, high-temperature sheathed heaters can also be manufactured using the method of the present invention using metal, ceramic, or a combination thereof as tubes, and in each case no special equipment, technology is required. It has the effect of being able to be easily and reliably manufactured without requiring additional cost, and can be supplied at a reduced price.

[Brief explanation of drawings]

Stripe 1 is a partially cross-sectional explanatory diagram showing one embodiment of the present invention;
Figure 3 is a partial cross-sectional view showing another embodiment of the present invention, Figure 4 is a cross-sectional view along the Moum line of Figure 3, and Figure 6 is a center cross-sectional view of the product. It is a cross-sectional explanatory view. In the figure, (6) indicates the holder, and (→ indicates the electrode. Representative: Ide -

Claims (1)

[Claims] ■The end of the raw material (electrodeposited on the resistive wire (electrodeposited on the wire, and made into a thin tube if necessary) is attached to the end of the liquid dispersion etc. A method for fixing a resistance wire in a thin tube, which is characterized by solidifying an insulating material in a coating manner.