JPH10221145A - Flow rate detector for liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable highly reliable detection of a flow rate under the environment of large vibration and oscillation by providing a retention chamber at a part of a passage surrounding a temperature sensor while a member of the retention chamber employs a heat insulating material. SOLUTION: A temperature sensor 2 is installed at a lower part of a passage 1. A partition member 4 having an opening part 5 at an upper part thereof is installed on the upstream side closer to the temperature sensor 2 and on the downstream side closer thereto and a retention chamber 3 is formed surrounding the temperature sensor 2 with the passage 1 and the partition members 4. Even in case the oscillation and the vibration are caused in the passage 1, the liquid in the retention chamber 3 is confined in the retention chamber 3 to be kept from flowing outside the retention chamber 3, which also can prevent the dissipation of heat generated from the temperature sensor 2 outside the retention chamber 3. A heat insulating material 6 is applied on the internal surface of the partition members 4 as facing the retention chamber 3 or the partition members 4 are made of the heat insulating material 6. Moreover, it is desired that the heat insulating material 6 is also applied on the internal surface of the passage 1 facing the retention chamber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a flow rate of a liquid flowing through a flow path such as a pipe in an environment such as a ship or an automobile where vibration or shaking is large.

[0002]

2. Description of the Related Art Conventionally, there has been known a liquid flow rate detecting device using a self-heating type temperature sensor utilizing self-heating of a thermistor or an indirectly heating type temperature sensor combining a thermistor and a heating means such as a heater.

In these apparatuses, a heating means such as a thermistor (self-heating type) or a heater (indirectly heating type) is used.
A constant heat is generated by this, but this heat is radiated to the periphery of the sensor. It can be known by indirectly detecting the voltage.

That is, when the flow rate of the liquid flowing through the flow path is large, the heat generated from the heating means (heater) is immediately absorbed by the liquid and moves downstream of the flow path. In other words, heat dissipation is good.

As a result, the temperature of the thermistor, which is a temperature sensor, decreases, and the resistance of the thermistor increases.
Conversely, when the flow rate is small, heat is less likely to be transmitted to the liquid, and the heat is dissipated poorly. As a result, the temperature of the thermistor, which is a temperature sensor, rises, and its resistance value falls.

Therefore, the flow rate of the liquid flowing through the flow path can be detected by detecting the resistance value of the temperature sensor (thermistor).

However, when a pump for a cooling water system or the like is stopped in a ship, an automobile, or the like, or when the pump breaks down, the liquid does not flow in the flow path but remains at the bottom of the flow path. .

[0008] When a ship, an automobile, or the like receives a large vibration or shaking from the outside, the liquid stored in the bottom of the flow path swings right and left, and flows around the temperature sensor at a certain flow velocity.

As a result, a heat dissipation state similar to that in the case where the liquid is flowing in the flow path at a certain constant flow velocity is created, and the resistance value of the thermistor, which is a temperature sensor, also increases.
The same change as in the case where the liquid flows is shown, and there has been a problem that erroneous detection is performed as if the liquid were flowing in the flow path.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide a highly reliable liquid flow rate detecting device even in an environment where vibration and shaking are large. Is what you do.

[0011]

The inventor of the present invention has made intensive studies to solve the above-mentioned problems, and as a result, in order to prevent heat from being dissipated due to vibration or shaking of the liquid, one of the flow passages has been formed so as to surround the temperature sensor. Consider providing a storage room in the department,
Furthermore, the present invention has been completed by paying attention to the use of a heat insulating material for members constituting the storage chamber.

That is, the present invention provides (1) a liquid flow rate detection device using a self-heating type temperature sensor or an indirectly heated type temperature sensor, wherein a storage chamber surrounding the temperature sensor is provided in the middle of the liquid flow path. Liquid flow rate detecting device. (2) a partition member in which the storage chamber has an opening at the top,
Alternatively, the liquid flow rate detection device according to (1), wherein the device is configured by a cylindrical member. (3) The liquid flow rate detection device according to (1), wherein at least a part of the members forming the storage chamber is formed of a heat insulating material.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of the flow rate detecting device of the present invention, and FIG. 2 is a sectional view of a main part of FIG.

1 and 2, 1 is a flow path, 2 is a temperature sensor (self-heating type or indirectly heating type), 3 is a storage room, 4
Is a partition member, 5 is an opening, and 6 is a heat insulating material.

A temperature sensor 2 (indirectly heated type) having a built-in thermistor and a heater for heating is installed below the flow path 1.

A partition member 4 having an opening 5 at an upper portion is provided at a position adjacent to the upstream side and the downstream side of the temperature sensor 2, and the temperature sensor 2 is formed by the flow path 1 and the partition member 4.
Is formed.

Therefore, even if the flow path 1 is shaken or vibrated,
The liquid in the storage chamber 3 is confined in the storage chamber 3 and does not flow out of the storage chamber, and at the same time, the heat generated from the temperature sensor 2 can be prevented from dissipating outside the storage chamber 3.

That is, there is no change in the resistance value of the thermistor built in the temperature sensor 2 and malfunction can be prevented.

An opening 5 through which the liquid passes through the flow path 1 is provided above the partition member 4. Here, the height, thickness, and position, size, and shape of the opening 5 provided in the partition member 4 are appropriate values depending on the magnitude of shaking or vibration, or the application. The shape is selectable.

The volume of the storage chamber 3 is particularly preferably 10 to 500 times the volume of the temperature sensor 2. In FIGS. 1 and 2, the number of the partition members 4 is two. However, if the number of the partition members 4 is four or more as shown in FIG. 3, it is possible to further reduce the influence of the vibration and the vibration.

Here, when the material of the partition member 4 is metal, since heat is largely dissipated from the storage chamber 3 to the outside, the heat insulating material 6 is applied to the inner surface of the partition member 4 facing the storage chamber 3. Or the material of the partition member 4 is made of the heat insulating material 6,
More accurate detection is preferred.

Furthermore, if the heat insulating material 6 is applied to the inner surface of the flow channel 1 facing the storage chamber 3, further effects can be expected.

In FIG. 1, FIG. 2, and FIG. 3, the storage chamber 3 is formed in the flow path 1 by the partition member 4, but is not limited to this. As shown in FIG. The storage chamber 3 is formed by the cylindrical member 4 having the opening 5, or as shown in FIG. Are possible.

Although the example in which the temperature sensor 2 is attached to the lower part of the flow path 1 is shown here, it is also possible to attach it to the upper part of the flow path.

[0025]

Embodiment In this embodiment, as shown in FIG. 6, a T-shaped pipe joint (see FIG. 6) is used as a flow path 1 in order to facilitate attachment to the apparatus main body for actually detecting the flow rate and to minimize the modification. (Inner diameter 15 mm) was used. The material was stainless steel (SUS316).

The temperature sensor 2 is mounted on the lower part of the center of the T-shaped pipe joint by a screw-in method, thereby facilitating the mounting. As the temperature sensor 2, an indirectly heated type was used.

The volume of the temperature sensor 2 is about 0.1 cm ³ , and the volume of the storage chamber 3 is set to about 1 cm ³ which is ten times as large. Therefore, the height of the partition member 4 is 8.9 mm from the upper end of the temperature sensor 2.

Further, the inner diameter of the partition member 4 is 5 m.
m openings 5 are provided. A 0.5 mm-thick epoxy resin is applied as a heat insulating material 6 to the partition member 4 facing the storage chamber 3.

In order to mount the apparatus in an actual flow path,
Although the flow path is cut and inserted in the middle, it is necessary to connect the connecting portions individually with T-shaped pipe joints having a diameter that matches the flow path diameter (outer diameter, inner diameter) on the device body side.

Here, a method of inserting a flow detecting device using a separate T-shaped pipe joint as shown in FIG. 6 in the middle of the flow path on the device main body side where the liquid flow detecting device is mounted is described. As shown in FIG.
It is needless to say that this method is not necessary when the method is made as described above, or when a method of modifying the flow path on the apparatus main body side is adopted later.

[0031]

According to the liquid flow rate detecting device of the present invention,
The flow rate of the liquid can be detected stably without being affected by external vibration or shaking.

Further, even when bubbles are mixed in the liquid, the bubbles are removed by the partition member or the like, and malfunction due to the bubbles can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a liquid flow rate detection device of the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a perspective view showing an embodiment having four partition members.

FIG. 4 is a sectional view of a main part showing another embodiment in which the storage chamber is cylindrical.

FIG. 5 is a cross-sectional view of a main part showing still another embodiment in which a storage chamber is separately provided outside a flow path.

FIG. 6 is a sectional view of a main part showing a flow rate detecting device of the present invention using a T-shaped pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow path 2 Temperature sensor (self-heating type or indirectly heated type) 3 Storage room 4 Partition member 5 Opening 6 Insulation material

Claims (3)

[Claims] 1. A liquid flow rate detection device utilizing a self-heating type temperature sensor or an indirectly heated type temperature sensor, wherein a storage chamber surrounding the temperature sensor is provided in the middle of the liquid flow path. Flow detector. 2. The liquid flow rate detecting device according to claim 1, wherein the storage chamber is constituted by a partition member having an opening at an upper portion, or a cylindrical member. 3. The storage chamber according to claim 1, wherein at least a part of the member forming the storage chamber is formed of a heat insulating material.
A flow rate detection device for a liquid according to the above.