JPH04306Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a gas rate sensor that detects the angular velocity of an object by deflecting a gas flow.
In particular, the present invention relates to an improvement in a means for connecting and fixing a temperature sensing element of a flow sensor that detects the deflection of a gas flow and a stud that holds the temperature sensing element.

(Conventional technology and its problems) An angular velocity sensor, generally called a gas rate sensor, has a gas flow ejected from a nozzle toward the temperature sensing element of the flow sensor in a sealed casing. The magnitude of the angular velocity (rate) is detected by the change in the output value of the flow sensor that occurs when the gas flow is deflected due to the influence of the applied angular velocity. This type of gas rate sensor is more resistant to vibration than a gyro compass, has high sensitivity, and has excellent responsiveness, so it is used for course adjustment or attitude control of ships, automobiles, etc.

As shown in FIG. 1, this gas rate sensor has a sensor main body 2 fitted into a casing 1, and the front and rear ends of this sensor main body 2 are provided with end plates 3 and 4.
sealed by. A nozzle piece 5 having a nozzle hole 5a and a rectifying hole 5b is formed at one end of the sensor body 2, and the other end is fixed to the casing 1 via a holder 6. Holder 7
is fitted into the sensor main body 2 near the holder 6, and a flow sensor 8 for detecting gas flow velocity is disposed in the holder 7 at a position facing the nozzle hole 5a. This flow sensor 8 is formed of a pair of temperature sensing elements 8a and 8b arranged at a predetermined interval. As shown in FIG. 2, both ends of the temperature sensing element 8a abut against the end surfaces 81a and 82a of two studs 81 and 82, which are inserted and fixed vertically into the holder 7 at a predetermined interval, and there is a gap between them. are connected and fixed by bonding 84 and 85.
The temperature sensor 8b is also formed similarly to the temperature sensor 8a.

A pump chamber 9 is formed between the holder 6 and the end plate 3, and an orifice 1 is provided in this pump chamber 9.
A piezo plate 10 with holes 0a is housed therein. The piezo plate 10 is configured to vibrate due to the current supplied through the connection terminal 11, and the gas in the pump chamber 9 is compressed by the pumping action caused by this vibration. A gas flow passage 12 is formed in the axial direction between the casing 1 and the sensor body 2.
One end thereof is communicated with the pump chamber 9 via the flow path 13 and the discharge hole 6a of the holder 6, and the other end thereof is communicated with the nozzle hole 5a and the rectification hole 5b through the flow path 14, respectively.

In this configuration, when the piezo plate 10 is energized and vibrates, the gas in the left side portion of the piezo plate 10 of the pump chamber 9 is compressed and flows into the flow path 12 through the orifice 10a of the piezo plate 10 and the discharge hole 6a of the holder 6. It flows in the axial direction and reaches the flow path 14 . The gas in the flow path 14 is ejected from the nozzle hole 5a into the inner flow path 15 toward the temperature sensing elements 8a, 8b. Next, the piezo plate 1 of the pump chamber 9 passes through the through hole 7a of the holder 7 and the exhaust chamber 16.
0 is returned to the left side of the piezo plate 10 of the pump chamber 9 through the orifice 10a. Here, when an angular velocity is applied to the gas rate sensor from the outside, the gas flow is deflected within the inner flow path 15, and a slight difference occurs in the output between the two temperature sensing elements 8a and 8b. Based on this output deviation, the angular velocity acting on the gas rate sensor is detected.

As mentioned above, this type of gas rate sensor detects the angular velocity based on the slight difference in the heat radiation distribution of the gas that the temperature sensing element pair receives from the gas flow. It is necessary to improve the mounting accuracy and to ensure electrical and thermal stability.

However, in the gas rate sensor, each stud of the flow sensor and the temperature sensing element are fixed at one location and at an appropriate location, and furthermore, there is a large difference in heat capacity between the stud and the temperature sensing element. It is difficult to obtain sufficient connection strength due to poor physical connection conditions, etc.
Because it is difficult to place the temperature sensing element straight between the studs, it is not possible to accurately detect the gas flow. On the other hand, the contact resistance between the two is large, and the temperature coefficient of resistance of the temperature sensing element changes, and in some cases, vibrations received by the casing are transmitted to the temperature sensing element, causing it to vibrate and generate electricity. The drawback was that the sensor became physically and thermally unstable, resulting in a decrease in the detection accuracy of the sensor.

This invention connects and fixes the temperature sensing element and the stud firmly, mechanically and electrically with high precision.
The purpose is to provide an electrically and thermally stable gas rate sensor.

(Means for Solving the Problems) In order to achieve the above object, a sensor is installed inside the sensor body through the nozzle hole of the sensor body housed in the casing, and both sides are fixed to the base via studs. In the gas rate sensor that detects the angular velocity based on a change in the output of the flow sensor based on a deflection of gas that occurs when an angular velocity acts on a gas flow ejected toward a flow sensor having a temperature sensing element, the temperature sensing element and gold plating is applied to each of the studs, each end of the temperature sensing element and the stud are connected and fixed at at least two places by bonding, and at least one of the ends is connected to the stud at the innermost position of the stud. It is characterized by being fixed.

(Function) Since one of the two fixed locations at each end of the temperature sensing element is placed at the innermost position of the stud, the resistance value of the temperature sensing element between the innermost positions will change even if it receives a gas flow. do not.

In addition, each end of the temperature sensing element is fixed at one more point in addition to the innermost position of the stud, so the temperature sensing element is firmly connected to the stud, and tension is applied to the temperature sensing element. At the same time, it is possible to prevent displacement and sagging of the temperature sensing element and fluctuations in contact resistance due to vibration of the casing.

Furthermore, since the temperature sensing element and the stud are each plated with gold and the gold is fused together to connect the temperature sensing element and the stud, the contact resistance is low.

(Example) An example of the present invention will be described below in detail based on the accompanying drawings.

An embodiment of the present invention is shown in FIGS. 3 and 4, and the holder 20 is a circular disk for forming the base of the flow sensor like the holder 7, and a through hole 20a is formed in the center in the radial direction. A plurality of, for example, four, through holes 20b are bored at equal intervals on the concentric circles. Furthermore, four holes 21a to 21d are bored concentrically between these through holes 20a and 20b. Studs 22 to 25 are inserted and fixed into these holes 21a to 21d. Each of these studs 22 to 25 is made of, for example, a tungsten member, and has a nickel plating as a base plating and a gold plating on the surface. The studs 22 to 25 are arranged perpendicularly to the board surface 20c of the holder 20, and each stud 22 to 25 is arranged perpendicularly to the board surface 20c of the holder 20.
The distances to one side end surface of .about.25 are equal.

The temperature sensing element 26 is a heating wire, for example, made of a thin tungsten wire, and its surface is plated with gold like the stud.
One end 26a of this temperature sensing element 26 is connected to the stud 22.
The other end 26b is in contact with the end surface 22a of the stud 23 (FIG. 4), and each of the studs 22, 23 and the temperature sensing element 26 are bonded 30 at several locations, for example, at two locations. ,31,
32 and 33. Connection by bonding is performed, for example, by inserting a thin gold wire for bonding into a cylindrical jig having an orifice hole of about 30μ in diameter, melting it at the orifice hole, and eluting it from the orifice hole to a predetermined bonding location. . One bonding 30,3 for each stud 22,23
2 connects the temperature sensing element 26 to each of these studs 22, 2.
3, and is connected at an appropriate location outside the axis of the stud. The position of the other bonding 31, 33 of each stud 22, 23 is on the innermost side surface 22b, 23b (the fourth
It is set at the periphery of the end face that matches the figure). In this way, the temperature sensing element 2 is attached to the studs 22 and 23.
Connect and fix 6. Similarly, studs 24,2
The temperature sensing element 27 is connected and fixed to 5.

The holder 20 having such a configuration is used as the holder 7 (first
It is installed inside the sensor body 2 instead of the one shown in the figure. Each temperature sensing element 26 and 27 is bonded to the studs 22, 23 and 24, 25 at two locations, and one location is located at the innermost end of the stud, so that it is firmly fixed to the stud. The contact resistance between them is very small. Further, even if the temporary casing 1 vibrates, the temperature sensing elements 26 and 27 do not vibrate, and the contact resistance does not fluctuate. Therefore, the temperature sensing elements 26 and 27 are extremely stable electrically and thermally, and the detection accuracy of the sensor is accordingly improved.

Further, as mentioned above, tungsten is used as the material for the temperature sensing element and the stud, and the temperature sensing element and the stud are each plated with gold, and the gold is fused together to connect the temperature sensing element and the stud. As a result, the temperature sensing element does not receive heat exceeding the melting point of the element, and therefore various characteristics of the temperature sensing element including the temperature coefficient of resistance do not change, and detection accuracy is improved.

(Effects of the invention) As explained above, according to the gas rate sensor of this invention, one of the two fixed locations at each end of the temperature sensing element is located at the innermost position of the stud, so that the gas flow can be controlled. The resistance value of the temperature sensing element between the innermost positions does not change even if the temperature is affected by the temperature change, and the resistance value of the temperature sensing element between the innermost positions does not change, resulting in electrical stability and improved detection accuracy.

In addition, each end of the temperature sensing element is fixed at one more location in addition to the innermost position of the stud, so the temperature sensing element is firmly connected to the stud, and vibration of the casing can cause damage to the temperature sensing element. It prevents misalignment, sagging, and fluctuations in contact resistance, improves electrical stability, improves detection accuracy, and allows the temperature-sensitive element to be installed with tension between the studs, which reduces gas flow. can be detected with high precision.

Further, since the temperature sensing element and the stud are each plated with gold and the gold is fused together to connect the temperature sensing element and the stud, the contact resistance is small, contributing to improved detection accuracy.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the gas rate sensor, Fig. 2 is a cross-sectional view of a conventional flow sensor used in the gas rate sensor of Fig. 1, and Fig. 3 is a flowchart used in the gas rate sensor according to the invention. FIG. 4 is an end view showing one embodiment of the sensor, and FIG. 4 is a sectional view taken along line AA' in FIG. 1...Casing, 2...Sensor body, 5a...
... Nozzle hole, 8 ... Flow sensor, 20 ... Holder (base), 22, 23 ... Stud, 26,
27...Temperature sensor (temperature sensing element), 30, 31,
32, 33...Bonding.

Claims (1)

[Scope of utility model registration request] In response to a gas flow ejected from the nozzle hole of the sensor body housed in the casing toward the flow sensor that has a temperature sensing element arranged inside the sensor body and fixed to the base via studs at both ends, respectively. In the gas rate sensor that detects the angular velocity based on a change in the output of the flow sensor based on the deflection of the gas that occurs when an angular velocity acts on the gas rate sensor, each of the temperature sensing element and both studs is plated with gold, and the temperature sensing element is plated with gold. A gas rate sensor characterized in that each end of the stud is connected and fixed to the stud at at least two places by bonding, and at least one of the ends is fixed at the innermost position of the stud.