JPH0769341B2 - Fluid velocity measurement probe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluid velocity measuring probe for measuring a moving velocity of a fluid, and more specifically, a resistance of a small piece of germanium single crystal due to temperature change. The present invention relates to a probe for measuring a fluid velocity using a change in value.

[Conventional technology]

The applicant of the present application, in Japanese Patent Application No. 61-140965, spherically coats a sensor, which is a small piece of germanium single crystal, with an electrically insulating coating material to reduce the directivity of the sensor with respect to the direction of fluid flow. "Probe for measuring fluid velocity" was presented.

Here, by using a small piece of germanium single crystal as the sensor, the problem of handling and life which is the defect of the hot wire anemometer using the coil of tungsten or platinum is solved, and the sensor is spherically coated. This reduces the directivity of the sensor.

However, as the jacket material, for example, an electrically insulating synthetic resin is used, and due to the heat insulating property of the material, it is difficult to measure a minute temperature change on the probe surface due to contact with a fluid, Moreover, it is impossible to completely eliminate the directivity of the sensor.

[Problems to be Solved by the Invention]

In view of the above problems, the present invention uses a small piece of germanium single crystal that is easy to handle and has a long life, and has little directivity,
An object of the present invention is to provide a probe for measuring a fluid velocity, which can accurately measure a fluid velocity.

[Means for solving the problem]

In order to achieve the above-mentioned object of the present invention, a base having an internal hollow having a terminal at the base end in the longitudinal direction, a support having an internal hollow attached to the tip of the base, A sensor consisting of a small piece of single crystal germanium arranged at the tip of the support,
Lead wires drawn from both ends in the length direction of the sensor,
A covering member which is connected to the lead wire and which is a wiring member disposed in the hollow portion of the support and the base and a metal sphere having a sensor insertion hole, and through which the sensor is inserted. A thin exposed portion provided between the covering member and the support and having elasticity formed by fixing a wiring member with a synthetic resin; and the sensor, the exposed portion, the wiring member and the inner surface of the covering member. A synthetic resin insulating member that is fixed in a separated state, and a voltage is applied to the sensor to maintain a constant temperature, and a change in the resistance value of the sensor due to the fluid coming into contact with the covering member , Convert to current or power,
The fluid velocity is measured based on the output, and the rate of change of the output is suppressed within 3% within an angle range of ± 50 degrees between the probe length direction and the fluid flow. For configuring the probe.

Here, as the covering member, a metallic sphere selected from copper, aluminum, gold, and silver can be used.

Further, an epoxy resin can be used as the insulating member.

Furthermore, it is possible to use a thin phosphor bronze wire as the wiring material.

[Action]

The probe for fluid velocity measurement according to the present invention is configured as described above, through the wiring material, a voltage is applied to a sensor made of a small piece of germanium single crystal to maintain a constant temperature,
The change in the resistance value of the sensor, which changes when the fluid comes into contact with the sensor, is converted into a voltage, a current, or an electric power, and the fluid velocity is measured based on this output.

Here, since the sensor made of single crystal germanium is covered with the covering member which is a spherical body made of metal, it is possible to accurately measure the velocity of the fluid flow from almost all directions.

In addition, the thin exposed portion having elasticity provided between the cover member and the support body enhances the heat insulation between the support body, the cover member and the sensor to improve the measurement accuracy and the impact resistance of the cover member. To do.

In particular, by using a metal sphere having a high thermal conductivity as the coating member, it is possible to accurately measure the fluid velocity, and the material is copper, aluminum, gold, or silver. You can use your choice.

Further, if the wiring material exposed from the tip of the support is fixed by an insulating member made of synthetic resin, the insulating member acts as a cushioning material and damage to the probe can be prevented.

Here, as the insulating member filled in the gap between the covering member and the sensor, a synthetic resin having a high thermal conductivity and a low electric conductivity is adopted. It is possible to provide a probe for use.

〔Example〕

 The details of the present invention will be explained based on illustrated embodiments.

FIG. 1 is a side view for explaining a first embodiment of a fluid velocity measuring probe according to the present invention, and FIG. 2 is a partially enlarged sectional view for explaining the first embodiment of the present invention.

In the figure, reference numeral 1 denotes a base having a terminal 2 at the base end in the length direction and an inner hollow in the length direction. For example, a ceramic pipe is used, but the material is not particularly limited. Absent.

Reference numeral 3 denotes an internal hollow support attached to the tip of the base 1. As the support 3, for example, a nickel pipe is adopted in consideration of strength, cost, and the like.
Other materials are not particularly limited.

Reference numeral 4 denotes a sensor made of a small piece of germanium single crystal having an outer shape of a rectangular parallelepiped, which is located at an upper end portion and a lower end portion of a side surface of the sensor 4, and is a lead wire 5 made of a good electric conductor such as gold, silver or platinum. 6 is attached.

Reference numeral 7 denotes a wiring material to which the lead wires 5 and 6 drawn out from the sensor 4 are connected. The wiring material 7 includes a covered wire 8 and a copper wire 9 covered with an insulating material, and the copper wire 9 is a covered wire. In the state of being wound around 8, the support 3 and the base 1 are arranged in the hollow inside, and the terminal 2 is inserted through the hollow inside of the base 1.
Is connected to.

At this time, the copper wire 9 wound around the covered wire 8 is fixed by a fixing member 12 made of synthetic resin or the like, and the fixing member 12 is made of epoxy resin or the like.

Reference numeral 10 denotes a coating member made of a metal sphere having a sensor insertion hole 11, and the coating member 10 is made of a metal having a high thermal conductivity, such as copper, aluminum, gold, silver, etc. In consideration of workability, it is preferable to use copper or aluminum.

When copper is used as the coating member 10, the surface is likely to be oxidized, so it is necessary to perform a plating treatment with gold or the like, and when aluminum is used, by forming a corrosion-resistant oxide film. The surface is prevented from oxidation.

Reference numeral 13 denotes an insulating member that fixes the sensor 4 in a state of being separated from the support body 3, the wiring member 7, and the inner surface of the covering member 10. The insulating member 13 is at least an electrically insulating material, Various kinds of resins can be used, and for example, synthetic resins such as epoxy resin, silicon resin, aniline resin, phenol resin, polyester resin, urethane resin and the like can be adopted. Here, epoxy resin is used.

A process of manufacturing an example of the fluid velocity measuring probe according to the present invention will be described.

First, the support 3 made of a nickel pipe having an outer diameter of 0.8 mm, an inner diameter of 0.6 mm, and a length of 30 mm is covered with an insulating material by 0.26 mm.
The coated wire 8 having a diameter and the copper wire 9 having a diameter of 0.1 mm are inserted.

A copper wire 9 is wound around the covered wire 8, and the copper wire 9 is fixed by a fixing member 12 made of epoxy resin.

At this time, the copper wire 9 is wound around the covered wire 8 and a part of the wiring member 7 fixed by the fixing member 12 is located at the tip of the support body 3 to form a thin exposed portion 14 having elasticity. To do so.

Next, the lead wires 5 and 6 drawn from the sensor 4 having a rectangular parallelepiped shape of 0.3 mm × 0.3 mm × 1.5 mm, the covered wire 8 of the wiring material 7 and the copper wire 9 are connected to each other, and the sensor 4 is fixed with an epoxy resin. It is fixed at the tip of the support 3.

FIG. 3 is an explanatory side view showing the state at this time.

That is, the epoxy resin 15 is used to position the sensor 4 at the tip of the exposed portion 14 of the wiring member 7 and to fix it separately from the wiring member 7 so that the epoxy resin 15 is formed integrally with the exposed portion 14. , The sensor 4 is arranged so as not to come into direct contact with the support 3 and the wiring member 7, and the heat of the sensor 4 is applied to the support 3
Also, the wiring material 7 is prevented from escaping.

After that, the wiring member 7 arranged in the inner hollow of the support 3 is extended to the inner hollow of the base 1 to be connected to the terminal 2 of the base 1, and the rear end of the support 3 is connected to the base 1. Install on.

Further, the insertion hole 11 of the metallic covering member 10 is filled with the insulating member 13 made of epoxy resin, and the sensor 4 attached to the tip of the support 3 is inserted.

At this time, the insulating member 13 overflowing from the insertion hole 11 of the covering member 10 adheres to the surface of the covering member 10 and the exposed portion 14 of the wiring member 7, is positioned at the tip of the support body 3, and is covered with the covering member 10. Firmly fix.

The fluid velocity measuring probe of the present invention is produced as described above, and since the sensor 4 is covered with the coating member 10 made of a metal sphere having a high thermal conductivity, the sensor 4 is oriented according to the direction of the fluid flow. It is possible to almost eliminate the property, and it becomes possible to accurately measure the velocity of the fluid.

Of course, since a small piece of germanium single crystal is used as the sensor 4, unlike the anemometer using a hot wire such as platinum or tungsten, there are no problems in handling and life.

The use of a metal such as copper or aluminum as the covering member 10 has a high thermal conductivity, so that a change in the surface temperature is faithfully transmitted to the sensor 4, and the workability is good. It has an advantage that a sphere can be easily formed.

In addition, an insulating member 13 for fixing the sensor 4 and the covering member 10
As, since the epoxy resin is used, it is easy to manufacture the probe, and the temperature change on the surface of the covering member 10 is surely transmitted to the sensor 4, and the space between the sensor 4 and the wiring member 7 is ensured. It is capable of retaining heat insulation.

Further, since the covering member 10 including the sensor 4 is fixed in a state of being separated from the tip of the support body 3, heat insulation between the sensor 4 and the support body 3 is maintained, and the wiring member 7 is fixed. The fixing member 12 made of epoxy resin is an insulating member
Since the covering member 10 is integrally supported with the exposed portion 14,
Acts as a cushioning material and prevents damage to the probe.

As the metallic covering member 10, the one shown in FIG. 4 can be used.

That is, it is a metallic sphere having a high thermal conductivity, has an insertion hole 11 into which the sensor 4 can be inserted, and further has a through hole 16 for venting air.
Is drilled.

Similar to the one shown in FIG. 2, this covering member 10 is made of copper, aluminum, gold, silver or the like, and it is preferable to use copper or aluminum in view of workability and cost.

Of course, in the case of copper, an anti-oxidation plating process is performed, and in the case of aluminum, a corrosion-resistant oxide film is formed.

If the covering member 10 thus configured is used, when the sensor 4 is inserted into the insertion hole 11, the epoxy resin filled in the insertion hole 11 is pushed out into the through hole 16 and air is introduced into the insertion hole 11. It will not remain.

If air remains in the epoxy resin in the insertion hole 11, it will be impossible to measure the speed accurately due to heat insulation with air.Therefore, it is necessary to take care so that no air remains. By using, it is possible to easily prevent air from remaining.

The fluid velocity measuring probe according to the present invention as described above applies a voltage to the sensor 4 via the terminal 2 and the wiring member 7 to raise the temperature of the sensor 4 to a constant temperature.

Although the sensor 4 is cooled by the contact with the fluid, the velocity of the fluid can be measured by changing the voltage so as to maintain a constant temperature and detecting the voltage change. .

Here, the angle formed by the plane perpendicular to the length direction of the probe to the flow of the fluid is α, the probe was rotated so as to change this angle α, and the result of measuring the terminal voltage was shown in FIG. Shown in.

As the external conditions at this time, the experimental results are shown in which the fluid velocity is constant at 5 m / sec, the vertical axis represents the voltage between the terminals of the probe, and the horizontal axis represents the angle α. That is, even if α changes within an angle range of -50 degrees to +50 degrees with reference to the output voltage of 7.9V when α = 0 degrees, the change of the output voltage is from -0.1V to +0.
It is 06V, the rate of change is -1.3% to + 0.8%, and the output voltage changes only 2.1% as a whole.

From this experimental result, the probe for measuring the fluid velocity according to the present invention can suppress the change in the output voltage due to the angle formed by the length direction of the sensor 4 and the flow of the fluid within 3%, and the directivity of the sensor 4 can be reduced. Can be eliminated, and the measurement error of the fluid velocity is almost eliminated.

Although the experimental result was not shown, it goes without saying that the sensor 4 is completely omnidirectional about the axis in the longitudinal direction, and the directivity of the sensor is reduced as much as possible in combination with the above results. It is possible to provide a probe for measuring a fluid velocity.

FIG. 6 is a sectional view for explaining a second embodiment of the fluid velocity measuring probe according to the present invention.

Reference numeral 4 denotes a sensor made of a small piece of germanium single crystal similar to that of the first embodiment, and is located at the upper and lower ends of the side surface of the sensor 4 and is a lead wire which is a good electric conductor such as gold, silver or platinum. 5 and 6 are attached.

Reference numeral 10 is a metal covering member similar to that shown in FIG. 4, and is a sphere having an insertion hole 11 through which the sensor 4 can be inserted and a through hole 16 for venting air.

This covering member 10 is also made of a material having a high thermal conductivity as in the case of the first embodiment, and copper, aluminum or the like is adopted, and in the case of copper, its surface is plated with an antioxidant to prevent oxidation. When aluminum is used, a corrosion resistant oxide film is formed on the surface.

Reference numeral 7 is a wiring member connected to the lead wires 5 and 6 drawn out from the sensor 4. In this second embodiment, thin phosphor bronze wires 17 and 18 are bonded by an insulating epoxy resin 19. is there.

The wiring material 7 to which the two thin wires 17 and 18 are adhered is inserted into the hollow of the support body 3 such as a nickel pipe as in the first embodiment, and is fixed by the insulating epoxy resin 20.

The support 3 is mounted on a base (not shown) as in the first embodiment.

The sensor 4 has an insertion hole for the covering member 10 as in the first embodiment.
It is inserted and fixed in a state where the epoxy resin is filled in 11 and the epoxy resin overflowing from the insertion hole 11 is removed at this time.

The fine phosphor bronze wires 17 and 18 are, for example, about 94% copper and about 9% tin.
Using a material with a small amount of phosphorus added to form a thin wire with a diameter of 0.15 mm and set the length of the exposed portion 14 located between the covering member 10 and the support 3 to 5 mm. The same thing as the first embodiment is used.

In the same manner as the first embodiment, the second embodiment thus configured is such that the angle formed by the plane perpendicular to the length direction of the corresponding probe to the fluid flow is α, and the probe is rotated so as to change this angle α. FIG. 7 shows the result of measuring the inter-terminal voltage.

The external conditions at this time are the results of an experiment in which the fluid velocity is constant at 5 m / sec, the vertical axis represents the voltage across the terminals of the probe, and the horizontal axis represents the angle α. That is, the output voltage when α = 0 degree 9.
Even if α changes within the angle range of −50 degrees to +50 degrees with reference to 6V, the change in the output voltage is −0.24V to + 0V, and the change rate is −2.5% to + 0%. as a whole
Output voltage changes only 2.5%, especially α is -40 degrees to +40
Within the angle range of degrees, the rate of change of output voltage is -1.3% to +
It is 0% and changes only 1.3% as a whole.

From this experimental result, in the second embodiment of the present invention, similarly to the first embodiment, the change in the output voltage due to the angle formed by the length direction of the sensor and the flow of the fluid can be suppressed within 3%. Since the directivity of No. 4 can be eliminated, the measurement error of the fluid velocity is almost eliminated.

This is related to the angle formed by the sensor 4 and the fluid flow because the sensor 4 is covered by the spherical coating member 10 formed of a material having a high thermal conductivity, as in the first embodiment. Instead, it is possible to measure the fluid velocity, and it is possible to deal with the fluid flow from any angle.

Further, since an epoxy resin or the like is used as the insulating member 13 that fixes the sensor 4 in a state of being separated from the support body 3, the wiring member 7 and the covering member 10, the surface of the metallic covering member 10 is The temperature change can be accurately transmitted to the sensor 4 to measure the fluid velocity.

Further, as the wiring member 7, a thin phosphor bronze wire 17 having elasticity,
Since the probe 18 is used, even if the probe comes into contact with another member and is deformed, it can be easily restored by the elasticity of the thin wires 17 and 18, and the shape of the probe can be maintained.

Since the strength at the joint between the wiring member 7 and the covering member 10 can be increased by using the thin phosphor bronze wires 17 and 18 as the wiring member 7 in this manner, the sensor 4 is inserted into the insertion hole 11 of the covering member 10. In doing so, the insulating member 13 overflowing the rim of the insertion hole 11 is unnecessary.

As a result, the sensitivity of the probe is further improved. In particular, since the insulating member 13 at the joint between the covering member 11 and the wiring member 7 is deleted, the measurement when the angle α becomes large The error can be minimized.

〔The invention's effect〕

The probe for fluid velocity measurement according to the present invention is as described above, and since it uses the sensor consisting of a small piece of germanium single crystal, it is a drawback of the hot wire anemometer using tungsten, platinum, etc. It is possible to solve the above problem, and the range of application to the fluid temperature is remarkably widened as compared with the case where a ready-made semiconductor element is used as a sensor.

In addition, since the sensor surface is coated with a coating member made of a metal sphere with high thermal conductivity, and a thin exposed portion is provided between the support and the coating member, the sensor length axis Of course, the directivity to the surroundings could be eliminated, and the directivity for the angle formed by the length direction of the probe and the direction of the fluid flow could also be minimized, that is, within the range of ± 50 degrees. It was possible to suppress the output change rate within 3% within this range. Therefore, regardless of the angle formed by the sensor and the direction of fluid flow, that is, when the fluid flow direction is unknown or temporal. It is possible to accurately measure the velocity of the fluid even when it changes to.

Further, since the epoxy resin is used as the insulating member for fixing the sensor and the covering member, the heat insulating property between the sensor and the support is good, and the heat conduction between the surface of the covering member and the sensor is good. The fluid velocity can be accurately measured.

Further, since the sensor and the covering member are separated from the support by the fixing member made of epoxy resin or the like, it is possible to maintain the heat insulating property of the sensor, and the elasticity of the fixing member or the wiring material causes It is possible to prevent damage.

[Brief description of drawings]

1 is a side view for explaining an embodiment of a fluid velocity measuring probe according to the present invention, FIG. 2 is a partially enlarged sectional view for explaining an embodiment of a fluid velocity measuring probe according to the present invention, and FIG. FIG. 4 is a side view for explaining a manufacturing process of a probe for measuring a fluid velocity according to the present invention, FIG. 4 is a sectional view for explaining another example of a covering member, and FIG. 5 is a diagram for explaining a probe for measuring a fluid velocity according to the present invention and a fluid. FIG. 6 is an output characteristic diagram according to an angle formed by a flow, FIG. 6 is a sectional view for explaining a second embodiment of a fluid velocity measuring probe according to the present invention,
FIG. 7 is an output characteristic diagram according to the angle formed by the second embodiment of the present invention and the fluid flow. 1: base, 2: terminal, 3: support, 4: sensor, 5: lead wire, 6:
Lead wire, 7: wiring material, 8: covered wire, 9: copper wire, 10: covering member, 11: insertion hole, 12: fixing member, 13: insulating member, 14: exposed portion, 15: epoxy resin, 16 : Through hole, 17: Thin wire, 18: Thin wire,
19: Epoxy resin, 20: Epoxy resin.

Claims (4)

[Claims] 1. A base, which has a terminal at the base end in the longitudinal direction and is hollow inside, a support having an inner hollow attached to the tip of the base, and a single crystal arranged at the tip of the support. A sensor made of a small piece of germanium, lead wires drawn out from both ends in the length direction of the sensor, wiring material connected to the lead wires and arranged in the hollow portion of the support body and the base, and sensor insertion An elastic member formed of a metal sphere having a hole, in which the sensor is inserted into the insertion hole, is provided between the covering member and the support, and the wiring material is fixed by a synthetic resin. A thin exposed portion having, and an insulating member made of synthetic resin for fixing the sensor in a state of being separated from the exposed portion, the wiring member and the inner surface of the covering member, and applying a voltage to the sensor to keep a constant temperature. Keep the fluid in contact with the covering The change in the resistance value of the sensor is converted into voltage, current or power, and the fluid velocity is measured based on the output, and the angle between the probe length direction and the fluid flow is within ± 50 degrees. A probe for measuring a fluid velocity, characterized in that the rate of change in output is suppressed within 3%. 2. The covering member is copper, aluminum, gold,
The probe for measuring a fluid velocity according to claim 1, wherein a metal sphere selected from silver is used. 3. A fluid velocity measuring probe according to claim 1, wherein an epoxy resin is used as the insulating member. 4. A probe for fluid velocity measurement according to claim 1, 2 or 3, wherein a thin phosphor bronze wire is used as the wiring material.