JPH031820Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a galvanometer that detects the flow rate of fluid flowing through a flow path by visually observing the position of a float.

(Prior art) A conventional galvanometer has a tapered hole in a part of the flow path, a float is placed inside the tapered hole, and the position where the float floats against its own weight is determined. There is a float type galvanometer that visually detects the flow rate of the detection fluid.

(Problem that the invention aims to solve) However, in this float type galvanometer, the float is displaced in a uniform proportional relationship according to fluctuations in the flow rate of the detected fluid. In order to do this, the movement range of the float had to be lengthened, and the display window for displaying the float position had to be enlarged accordingly, resulting in an increase in the size of the flowmeter. Furthermore, as the display window becomes larger, it becomes difficult to maintain its liquid tightness or airtightness. If it is sufficient to detect changes in the flow rate only when the flow rate of the detection fluid is low, the movement range of the float can be shortened, but this is insufficient as a galvanometer for detecting flow rate.

An object of the present invention is to provide a galvanometer that can detect the flow rate of fluid flowing through a flow path over a relatively wide range even when the float movement range is shortened.

(Means for Solving the Problems) The current galvanometer of the present invention includes a float chamber formed in the middle of a flow path with a diameter larger than the inner diameter of the flow path, a float housed in the float chamber, and a It includes a fitting that is fixed and can be fitted in the vicinity of the float chamber in the upstream portion of the flow path, and a display window formed on the outside of the float chamber to display the position of the float. The insert has a maximum diameter portion whose outer diameter is smaller than the inner diameter of the flow path, and a tapered portion that slopes toward the axis of the insert as it goes upstream from the maximum diameter portion of the flow path. It is set up. In addition, the float is placed in the float chamber so that the float operates in the range from the state in which the maximum diameter part of the fitter is fitted into the upstream portion of the flow path to the state in which the fitter is separated from the upstream portion of the flow path. accommodate.

(Function) In the galvanometer configured as described above, when no detection fluid is supplied to the flow path, the maximum diameter portion of the fitter fits into the upstream portion of the flow path, and the float moves upstream of the flow path in the float chamber. It is in contact with the partial side. Range where the flow rate of the detected fluid flowing through the flow path is small (micro flow range)
In this case, the maximum diameter part of the insert is fitted into the flow path, and at this time, the cross-sectional area of fluid passage formed between the maximum diameter part of the insert and the upstream part of the flow path is constant. be. Therefore, changes in fluid pressure due to increases or decreases in fluid flow rate act sensitively on the insert, and the float is sensitively displaced in response to changes in flow rate. Therefore, the period during which the maximum diameter portion of the fitter fits into the upstream portion of the flow path is the highly sensitive operating range of the float. Check the amount of float movement through the display window.

When the flow rate of the detected fluid increases beyond the micro flow rate range and the maximum diameter part of the insert separates from the upstream portion of the flow path, the cross-sectional area of fluid passage formed between the insert and the upstream portion of the flow path increases. changes depending on the inclination angle of the tape portion formed on the insert. When the flow rate changes, the float is displaced and the fluid passage cross-sectional area also changes in proportion to the change in flow rate, so the rate of change in flow velocity is small compared to the rate of change in flow rate. When the float is stationary at a certain position with only the tape part of the fitter fitted into the upstream part of the flow path, the pressure of the fluid applied to the float (including the fitter) from the upstream side and the weight of the float and the pressure applied to the float from the downstream side are balanced. According to the present invention, even when the flow rate increases, by slightly moving the insert, it is possible to obtain the passage cross-sectional area necessary for equilibrium in accordance with the increase in the flow rate. Therefore, within the variation range of the passage cross-sectional area (variation range of flow rate) that changes due to the tapered portion, the flow rate can be detected in equilibrium with the flow rate. On the other hand, if the insert does not have a tapered part, there are two types of changes in the cross-sectional area of passage of the fluid: before and after the insert leaves the upstream part of the flow path. However, in a state where the insert is separated from the upstream portion of the flow path, the passage cross-sectional area does not change, and a displacement in the flow rate cannot be detected. Also in the present invention, after the insert is separated from the upstream portion of the flow path, the flow rate cannot be substantially detected, as in the case where the insert is not provided with a tapered portion. After the maximum diameter part of the fitter leaves the upstream part of the flow path, the area from when the tapered part of the fitter separates from the upstream part of the flow path changes the cross-sectional area of the fluid according to the flow rate and becomes a float. is a low sensitivity region that changes depending on the flow rate.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 to 7.

The galvanometer of this embodiment has a tubular main body, and a flow path 2 is formed in the axial center of the main body. A float chamber 3 having an inner diameter larger than that of the flow path 2 is formed in series in the middle of the flow path 2 . The main body 1 has a pair of display windows 4 for peeking into the float chamber 3.
are provided at positions facing each other. Each display 4 is fitted with a transparent plate 5 for liquid-tightly or airtightly closing the display. A panel receiving portion 6 is formed in a downstream portion 2a of the flow path 2 adjacent to the float chamber 3. A float 7 is housed in the float chamber 3 so as to be able to float. As shown in detail in FIGS. 6 and 7, the float 7 includes a bottomed cylindrical base 8, a neck 9a protruding from the bottom 8a of the cylindrical base 8, and a body integral with the neck 9a. It is comprised of a fitting 9 consisting of a molded head 9b and a plurality of through holes 10 formed in the bottom 8a between the inner circumferential wall 8b of the base 8 and the neck 9a. The maximum diameter portion 9c of the head 9b of the insert 9 is the flow path 2.
It is formed so that it can fit near the float chamber 3 of the upstream portion 2b of the head 9b, and the maximum diameter portion 9 of the head 9b.
A slight gap is formed between the channel 2 and the channel 2 into which the maximum diameter portion 9c fits.
The insert 9 is further provided with a tapered portion 9d that slopes toward the axis of the insert 9 as it goes upstream of the flow path 2 from the maximum diameter portion 9c. A spring 11 is arranged between the float 7 and the spring receiving part 6, and this spring 11 causes the float 7 to move into the flow path 2.
is biased toward the upstream portion 2b of.

Next, in the above embodiment, the operation of each member when galvanometrically detecting the detection fluid flowing through the flow path will be described.
When the detection fluid is not supplied to the flow path 2, the fitting 9 of the float 7 is fitted into the upstream portion 2b of the flow path 2 due to the biasing force of the spring 11, as shown in FIG.
The bottom portion 8a of the base body 8 is in contact with the end surface of the upstream portion 2b of the flow path 2 of the float chamber 3. When a small amount of fluid is supplied to the flow path 2, the float 7 moves toward the downstream portion 2a of the flow path 2 against the urging force of the spring 11, as shown in FIG. The detection fluid flows through the gap between the portion 2b and the fitter 9 of the float 7 as shown by the arrow. At this time, between the maximum diameter portion 9c of the insert 9 and the upstream portion 2b,
The cross-sectional area between them (fluid passage cross-sectional area) BS1 is small and constant. Therefore, even if the flow rate increases, the passage cross-sectional area BS1 remains constant, so the flow velocity increases and the float is displaced with high sensitivity. As the flow velocity increases, the float is displaced with high sensitivity. Float 7 at this time
By moving , a part of the float 7 can be seen from the display window 4,
It can be confirmed that the fluid is flowing slightly. When the flow rate of the detection fluid flowing through the flow path 2 is further increased, as shown in FIG.
The area of the float 7 visible through the display window 4 increases, and it can be confirmed that more fluid is flowing. Next, when the flow rate of the detection fluid flowing through the flow path 2 increases further than the state shown in FIG. The base body 8 of the float 7 can be seen in its entirety from the display window 4 as it is separated from the portion 2b, and it can be confirmed that even more fluid is flowing. When the flow rate increases further, the float 7 comes into contact with the downstream wall of the float chamber 3 and stops. The range before the maximum diameter portion 9a separates from the upstream portion 2b of the flow path 2 when the flow rate is low and the maximum diameter portion 9c of the insert 9 of the float 7 is fitted into the upstream portion 2b of the flow path 2. In this case, the detection fluid flows through the narrow gap between the maximum diameter portion 9c of the insert 9 and the upstream portion of the flow path 2, and the float 7 is sensitively displaced to the downstream side of the flow path 2, so that the flow rate of the detection fluid increases. Even if there is a small amount of change, the amount of displacement of the float 7 appears large. In this way, the maximum diameter portion 9c of the insert 9
The range in which the maximum diameter portion 9c is fitted into the upstream portion 2b of the flow path 2 and before the maximum diameter portion 9c separates from the upstream portion 2b of the flow path 2 is configured as a high-sensitivity operating range.

Further, in a state where the flow rate is high and the maximum diameter portion 9c of the insert 9 of the float 7 is separated from the upstream portion 2b of the flow path 2 and the tapered portion 9d is located within the upstream portion 2b of the flow path 2, Even when the flow rate increases, as shown in FIGS. 3b and 4b, the edge 2b1 of the upstream portion 2b of the flow path 2 on the float chamber 3 side
The fluid passage cross-sectional areas BS2 and BS3 at the position increase and the float comes to rest at an equilibrium position. When the fluid passage cross-sectional areas BS2 and BS3 increase, the flow rate of the fluid increases, but the float is displaced at a much smaller displacement rate than in the high-sensitivity operating region. Therefore, until the tapered portion 9d separates from the upstream portion 2b, the flow rate can be detected with lower sensitivity than the high-sensitivity operating range. The range in which the maximum diameter portion 9c of the insert 9 is separated from the upstream portion 2b of the flow path 2 and the tapered portion 9d is located within the upstream portion of the flow path 2 constitutes a low-sensitivity operating range. .

In the galvanometer of the present invention, when supplying fluid at a constant pressure from a supply source such as a pump to a supplied device, a large amount of initially supplied fluid is supplied;
The flow rate of the fluid flowing through the channel can be detected over a wide range when the supplied device is almost filled with fluid and the flow rate of the supplied fluid is decreasing.

In the above embodiment, when the maximum diameter portion 9c of the fitter 9 of the float 7 is fitted into the upstream portion 2b of the flow path 2, fluid is not allowed to flow between the maximum diameter portion 9c and the upstream portion 2b. In the case of gas, it is suppressed to about 0.005mm.

In the galvanometer of the present invention, if a float chamber is provided in the middle of the vertical flow path, the spring 11 of the above embodiment can be omitted, and in this case, the float's own weight resists the flow of the detection fluid. It operates in a high-sensitivity operating range and a low-sensitivity operating range.

(Effect of the invention) As described above, according to the invention, while the maximum diameter part of the fitter provided on the float is fitted into the upstream part of the flow path, even if there is a small change in flow rate, the float As the amount of displacement increases, it is possible to detect the displacement of the flow rate with high sensitivity. With this, it is possible to detect with low sensitivity a change in flow rate that is proportional to a change in the fluid passage cross-sectional area determined by the inclination of the tapered portion. The detection width of the flow rate can be arbitrarily set by selecting the angle and length of the tapered portion provided on the insert. Therefore, according to the present invention, the flow rate can be detected with high sensitivity in a range where the fluid flow rate is small, and even if the movement range of the float is short, the flow rate can be detected within a certain range when the fluid flow rate increases. A galvanometer that can detect flow rate and has a relatively wide detection range can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the internal structure of the galvanometer of the present invention, and FIGS. Figures 2b, 3b, and 4b show fluid passage breaks between the upstream portion of the flow path and the float insert in each case of Figures 2a to 4a. 5 is an external view of the galvanometer of the present invention, FIG. 6 is a half sectional view of the float of the galvanometer of the present invention, and FIG. 7 is a plan view of FIG. 6. 2... Channel, 2b... Upstream portion of the channel, 3...
Float chamber, 4... Display window, 7... Float, 9
...Insert, 9c...Maximum diameter part of insulator, 9d...
Tapered part, BS1 to BS3...Fluid passage cross-sectional area.

Claims (1)

[Claims for Utility Model Registration] A float chamber formed in the middle of a flow path with a diameter larger than the inner diameter of the flow path, a float housed in the float chamber, and a float fixed to the float upstream of the flow path. a fitting that can be fitted in the vicinity of the float chamber of the section; and a display window formed on the outer side of the float chamber to display the position of the float, the fitting having an inner diameter dimension of the flow path. a maximum diameter portion having an outer diameter smaller than that of the insert, and a tapered portion that slopes toward the axis of the insert as it goes upstream from the maximum diameter portion of the flow path; The float operates in a range from a state in which the maximum diameter portion is fitted into an upstream portion of the flow path to a state in which the fitter is separated from the upstream portion of the flow path. A galvanometer characterized by being housed in a chamber.