JPS6040961A - Temperature controlling apparatus of gas rate sensor - Google Patents

Abstract

PURPOSE:To improve and stabilize angular velocity detecting accuracy of a gas rate sensor, by setting a gas pump generating a gas flow in a closely tight casing and 2 temperature sensitive elements in the gas flow. CONSTITUTION:An electrostrictive vibrating pump 3 is installed in a hermetrically sealed casing 1 by a pump holder 2 and further, holder 5 and nozzle 4 are incorporated by a hollow circular cylinder 13. Electrodes 6a, 6b, 6c, 6d and temperature sensitive elements 7a, 7b are held by the holder 5 and the nozzle 4 is supported to face them. In this case, a constant current independent on the ambient temperature is applied to the two elements 7a, 7b, and a temperature control is conducted with reference to the both-end voltage values of the temperature sensitive elements. Thus, the angular velocity inspection accuracy of the gas rate sensor is improved and stabilized.

Description

Detailed Description of the Invention The present invention relates to a temperature control device for a gas rate sensor, and in particular, a heater is provided on the outer surface of a casing constituting the sensor to maintain the temperature inside the sensor at a constant temperature without being affected by the temperature of the outside air. The present invention relates to a temperature control device for maintaining temperature.

To explain the structure of a conventional gas rate sensor, as shown in FIG. 1, the sealed casing / is cylindrical, and both ends are closed and sealed with a pump holder and a relay terminal plate / 7, respectively.

Inside the casing, an electrostrictive vibration pump 3 is placed by a pump holder λ, and a holder S and a nozzle hole are installed by a hollow cylinder /3, and electrodes O a, zb, xc, xd (Fig. 3) and a temperature sensing element 7a are installed. .

7b is held by a holder S, a nozzle is supported opposite to these, and the nozzle has a nozzle hole // and an auxiliary port 1.
It has 2. The pump chamber 1g of the electrostrictive vibration pump 3 has a flow path/
θ, the flow path /θ passes through the nozzle hole //, the auxiliary lower, 2, the internal flow path /3a in the hollow cylinder 13, and the outlet Ill formed in the holder S, /! ; is connected to. The relay terminal board /7 is provided with a work C unit 1-25 via a relay terminal /2, and the IC unit is provided with a terminal 27.

To explain the operation, the electrostrictive vibration pump 3 mounted on the pump holder is supplied with electrical energy by the IC unit and vibrates, compressing the gas in the pump chamber 1g and increasing the discharge log
, through the inlet 9 in the flow path 10 in the direction of the arrow, the gas flow reaches the nozzle, passes through the nozzle hole //, auxiliary port /2, toward the holder 5, and passes through the outlet /'I, /3. It flows like that. In this flow, the temperature sensing elements 7a, 7b are welded to the end faces of the electrodes 4a, 4'b, 6C, 4d as shown in Fig. 3, and the waste flow evenly spreads the temperature sensing elements 7a, 71). Cool and pass through. Angular velocity abdominal motion from the outside of the casing/
, the temperature sensing element is cooled unevenly due to the deflection of the gas flow in the internal flow path /Ja in the hollow cylinder 73.
The difference is output as a voltage. Since the output is a minute voltage, it is amplified by the engineering C unit 25 and output from the terminal 27 as an angular velocity signal.

As described above, since the gas rate sensor works by the difference in cooling of the temperature sensing element, it is necessarily sensitive to temperature.

Therefore, by controlling the casslate sensor to a constant temperature that is higher than the maximum temperature expected to be applied from the outside,
Protected from the effects of external temperature fluctuations.

Therefore, attempts have been made to control the temperature of conventional gas rate sensors, and the temperature control device consists of wrapping a heater wire 21 around the casing and keeping it warm with a heat insulating cover 22. To set the heating temperature, a temperature sensor 30 for detecting temperature is separately provided on the surface of the casing, the temperature of the casing is detected, and the temperature is controlled under constant conditions based on the detected value.

As mentioned earlier, Casrate sensors are affected by changes in outside air temperature which cannot be ignored, so there are problems such as the range of environments in which they can be used as Rate sensors is limited.
Conventionally, the above-mentioned temperature control device has been used, but its stability was insufficient.

This invention has been made in view of the above, and aims to provide a temperature control device for a gas rate sensor with high detection accuracy. By keeping the temperature constant, even when the temperature of the outside air changes, more accurate temperature control is possible.This allows for stable angular velocity detection.

In this invention, unlike the conventional method of detecting the casing surface temperature with a separate temperature sensor and controlling the temperature based on that value, this invention uses two temperature sensing elements connected in series to detect the external temperature. A constant current is applied regardless of the temperature, and the temperature is controlled based on the voltage value across the temperature sensing element.

For that purpose, for example, as shown in the figure, a temperature sensing element?
a, 71), the voltage across the wire 211. Relay terminal/
9 and the terminal core, and the current flowing through the heater wire is controlled intermittently so that the voltage becomes a constant value.

The present invention is constructed as described above, and the temperature is controlled based on the value detected from the temperature sensing element which is easily influenced by temperature in terms of performance of the rate sensor.In general, the temperature sensing element is Due to its extremely high temperature coefficient of resistance, the resistance at both ends of the temperature sensing element changes depending on the external temperature, so when a constant current is applied, the voltage changes in proportion to the above resistance change, making it accurate and highly accurate. Responsive temperature sensing is now possible, and temperature control can be performed reliably.As a result, it has the effect of improving and stabilizing the angular velocity detection accuracy of the gas rate sensor against external temperature changes. .

[Brief explanation of drawings]

Fig. 2 is a longitudinal sectional view of a conventional slate sensor, Fig. 2 is a longitudinal sectional view of a slate sensor according to an embodiment of the present invention, and Fig. 3 is a longitudinal sectional view of a conventional slate sensor.
The figure is a sectional view taken along line T1 in FIG. 2, and FIG. 4 is a circuit diagram of the present invention. /...casing, co-pump holter, 3...electrostrictive vibration pump, g...nosle, ri...holter, xa, ab,
xc, 4a,, electrode, 7a, ? b - Temperature sensing element, g
・Discharge port, wa... fathom opening, 10... flow path, //... nozzle hole, /2... auxiliary port, 13... hollow cylinder, i, ya...
Internal travel center js / e +75...Outlet, /6...Custpre-1, /ri...Relay terminal board, 7g...Pump chamber, /9...Relay terminal, U/...Heater wire, 2λ ...Insulation cover, Co S...C unit, Cor...Lead bin, Core...Terminal, 2g...Electric wire, 30...Temperature sensor, R1...Resistance of the same city. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] It has a gas pump that generates a gas flow in a sealed casing, and two temperature sensing elements placed in the gas flow, and when an angular velocity input is applied to the casing, the gas flow is proportional to the angular velocity input. A heater is installed on the outer surface of the casing of the gas rate sensor, which detects deflection based on resistance changes of the temperature sensing elements, to keep the temperature inside the sensor constant. A temperature control device for a gas rate sensor, comprising a device for controlling a heater on the outer surface of the casing using a voltage.