JPH0323534Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a non-circular gear type flowmeter, in particular,
This invention relates to an improvement in a device equipped with a means for optically measuring the rotation of a rotating body.

[Conventional technology]

As a conventional non-circular gear type flowmeter, a reflecting mirror is provided on at least one end face of a pair of non-circular gears meshed in a gear housing, and a light emitting element and a light receiving element are provided in a case. The number of rotations of a non-circular gear rotated by the flow of fluid is measured by detecting the light from a light emitting element reflected by a reflecting mirror at a light receiving element, and the flow rate proportional to the number of rotations is measured. Some devices are configured to perform measurements (see Japanese Utility Model Application Publication No. 161038/1983).

In such a non-circular gear type flowmeter, it is necessary to provide a transparent part on the wall of the case in order to guide light between the reflecting mirror arranged on the end face of the non-circular gear and the light emitting element and light receiving element. be. As a structure in which this transparent portion is provided, there is a conventional structure shown in FIGS. 4 and 5, for example.

In the structure shown in FIG. 4, a transparent member 35 formed in a small circular plate shape is fitted into a recess 32 formed in a case 31 at a location where a light emitting element 33 and a light receiving element 34 are installed. It is configured by being fixed using an adhesive 36.

In the structure shown in FIG. 5, a transparent member 35 is fitted into a recess 32 with a seal rubber 37 sandwiched therebetween, and a caulking portion 38 is formed at the opening edge of the recess 32 to secure it. It is composed of:

[Problem that the invention attempts to solve]

In the structure shown in FIG. 4, since the transparent member is fixed with an adhesive, there is a disadvantage that the type of fluid that can be handled is limited depending on the type of adhesive. For example, when a highly versatile epoxy adhesive is used, it is resistant to petroleum-based solvents but dissolves in alcohol-based solvents, making it unsuitable for handling alcohol-based liquids.

In the structure shown in Fig. 5, the transparent member is fixed by caulking, so if the transparent member is made of resin, the problem of creep remains, and if the transparent member is made of glass. If so, cracks are likely to occur during caulking.

[Means for solving problems]

The non-circular gear type flowmeter according to the present invention includes a gear housing 1, a working chamber 2 formed so that fluid flows through the gear housing 1, and a working chamber 2.
a pair of non-circular gears 7, 7 which are rotatably housed in each of the non-circular gears 7 and 7, which are meshed with each other; a reflective surface 9 provided on one end surface of at least one of the non-circular gears 7 so as to rotate together with the reflective surface 9; It is equipped with a light emitting element 19 and a light receiving element 20 which are respectively disposed so as to face the surface 9, and the light is reflected by the reflective surface 9 provided on the non-circular gear 7 which is rotated by the flow of the fluid. In a non-circular gear type flowmeter configured to measure the flow rate by detecting light from a light emitting element 19 with a light receiving element 20, an annular groove 10 is formed on the end surface of the gear housing 1 on the reflective surface 9 side. The gear housing 1 is recessed so as to surround the opening of the working chamber 2, and an O-ring 11 is accommodated in the annular groove 10. A transparent member 12 formed in a plate shape to cover the O-ring 11 is pressed and abutted against the light emitting element 19 and the light receiving element 2.
0 is opposed to the reflective surface 9 with the transparent member 12 in between.

[Effect]

Since the transparent member covers the entire end face of the working chamber, no adhesive is required in the working chamber, and as a result, fluid handling limitations are eliminated.

Furthermore, since the transparent member is disposed to cover the entire end surface of the working chamber, creep phenomena, cracks, etc. due to caulking can be avoided. Since the O-ring 11 serves as a cushion when the transparent member 12 is brought into contact with the gear housing 1, it is possible to absorb excessive force when the transparent member 12 is brought into contact with the gear housing 1. can prevent cracking. Furthermore, the O-ring 11 can prevent fluid from leaking from the working chamber 2. That is, with this configuration, it is possible to adopt a configuration in which the entire opening of the working chamber 2 is covered with the transparent member 12.

〔Example〕

Fig. 1 is a vertical sectional view showing a non-circular gear type flowmeter which is an embodiment of the present invention, and Fig. 2 is a -
FIG. 3 is a partially omitted plan sectional view taken along the line, and FIG. 3 is a plan sectional view taken along the line -- in FIG.

In this embodiment, the non-circular gear type flowmeter includes a gear housing 1 which is made of stainless steel and formed into a rectangular parallelepiped with a planar shape of approximately square. It is opened at one end surface (hereinafter referred to as the top surface), and is formed into a column-shaped space having a planar shape formed by arranging two sets of large and small diameter semicircles in the shape of a cross. The gear housing 1 has an inlet passage 3 and an outlet passage 4 arranged at 180 degrees from each other (hereinafter referred to as the front-back direction) and opened so as to communicate with both small-diameter chambers of the working chamber 2, respectively. An inlet pipe 5 and an outlet pipe 6 are protruded from the front and rear surfaces of the gear housing 1 so as to connect to the inlet passage 3 and the outlet passage 4, respectively.

A pair of non-circular gears 7 are disposed in the working chamber 2 so as to mesh with each other, and both gears 7 are rotatably supported on respective support shafts 8 which are provided in the gear housing 1 in parallel to each other. The non-circular gear 7 is molded using carbon, resin, or the like.

A plurality of reflecting mirrors 9 as reflecting surfaces are arranged and fixed in the circumferential direction on a circle centered on the spindle 8 on one upper surface of the non-circular gear 7, and the reflecting mirrors 9 have a black background. The non-circular gear 7 is made of a material having a higher reflectance than the non-circular gear 7, such as aluminum, nickel, tin, silver, stainless steel, etc., and is fixed by suitable means such as plating, high-frequency welding, or embedding. ing.

A circular annular groove 10 is arranged and recessed in the upper surface of the gear housing 1 so as to surround the opening of the working chamber 2, and a circular O-ring 11 is accommodated in this groove 10. A glass plate 12 as a transparent member is brought into contact with the upper surface of the gear housing 1 so as to cover the opening of the working chamber 2, and the glass plate 12 is formed into a disc shape that is approximately the same as the outer shape of the annular groove 10. The lower outer circumferential portion thereof is adapted to be in close contact with the O-ring 11.

Further, on the upper surface of the gear housing 1, a cushion 13 made of an elastic material such as rubber and formed into a substantially square frame shape is disposed so as to surround the outside of the glass plate 12. At each of the four corners, spacers 14 formed as substantially trapezoidal flat plates slightly thicker than the glass plate 12 are arranged so as to be close to the outer periphery of the glass plate 12.

In the gear housing 1, a case 15 made of aluminum and formed to have substantially the same planar shape as the gear housing is stacked on top of the other with a glass plate 12, a cushion 13, and a spacer 14 in between. are fastened together by bolts 16 placed at their four corners. At this time, since the spacers 14 are arranged at the four corners, even if there is a variation in the tightening force, it is possible to avoid applying an excessive mechanical load to the glass plate 12. Furthermore, if a liquid gasket (not shown) is applied between the contact surfaces of the glass plate 12 and the case 15, the glass plate 12 can be further protected.

A pair of through holes 17 and 18 are arranged in the bottom wall of the case 15 at positions facing the reflecting mirror 9, and are opened at an angle so that the extension lines of the two substantially intersect on the surface of the reflecting mirror 9. There is. A light emitting element 19 is arranged and inserted in the upper part of one of the through holes 17 so as to project light onto the reflecting mirror 9, and a light receiving element 20 is inserted in the upper part of the other through hole 18 to receive the reflected light from the reflecting mirror 9. It is arranged and inserted so that it receives light. The light emitting element 19 and the light receiving element 20 are connected to an input/output device 21.
The case 15 includes electronic components or electronic equipment (not shown) necessary for measurement.

Next, the effect will be explained.

When the liquid to be measured as a working fluid is introduced into the working chamber 2 from the inlet pipe 5 through the inlet passage 3, the liquid operates in the working chamber 2 and then passes through the outlet passage 4 to the outlet pipe 6. It is derived from When the liquid passes through the working chamber 2, the pair of non-circular gears 7 that mesh with each other and partition the working chamber 2 are rotated by the flow in the direction shown by the dashed arrow in FIG.

On the other hand, the light emitted from the light emitting element 19 passes through the glass plate 12 and is irradiated onto the end face of the non-circular gear 7, where it is reflected. The reflected light passes through the glass plate 12 and is received by the light receiving element 20. At this time, the reflecting mirror 9
Since there is a large difference in reflectance between the black surface of the non-circular gear and the black surface of the non-circular gear, the rotational speed of the non-circular gear 7 can be measured based on the output of the light-receiving element 20.

Since the rotational speed of the non-circular gear 7 is proportional to the flow rate of the liquid rotating it, the flow rate can be substantially measured by measuring the rotational speed.

By the way, it is known that when water and aluminum come into contact, aluminum hydroxide is generated and the aluminum is corroded. Therefore, when water is handled by a flowmeter whose case is formed using aluminum, when water comes into contact with the case, the case corrodes. For this reason, such flowmeters cannot handle water.

However, in this embodiment, since the open end surface of the working chamber 2 is covered with the glass plate 12, water can be handled. That is, the liquid contacts the surface of the working chamber 2 of the gear housing 1 made of stainless steel and the glass plate, and does not come into contact with the lower surface of the case 15 made of aluminum. No corrosion occurs and as a result water can be handled.

In addition, the glass plate 12 and the gear housing 1
There is a risk that the sealing of the working chamber 2 cannot be completely maintained only by joining the two planes together.

However, in this embodiment, since the O-ring 11 is interposed between the glass plate 12 and the gear housing 1 so as to surround the working chamber 2,
The seal of the working chamber 2 can be completely maintained. Furthermore, since the O-ring 11 serves as a cushion between the glass plate 12 and the gear housing 1, cracking of the glass plate 12 during tightening is prevented.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified without departing from the gist thereof.
It goes without saying that various changes are possible.

For example, the transparent member is not limited to being formed using glass, but may be formed using transparent resin or the like.

The spacer may be omitted depending on the mechanical load on the glass plate.

[Effect of idea]

(1) By covering the entire end surface of the working chamber with a transparent member, all you have to do is contact the transparent member with the gear housing, which eliminates the process of gluing or caulking the transparent member, reducing the defect rate. and costs can be reduced.

(2) By not using adhesives that pose corrosion-resistant problems, if you use corrosion-resistant materials such as stainless steel or corrosion-resistant resin for gear housings, rotating bodies, and reflective surfaces, you can avoid the use of water, petroleum, or alcohol-based materials. , liquids such as chemicals, and gases such as air, that is, all fluids can be handled.

(3) Since the use of corrosion-resistant materials is not required for cases with complex shapes, the cases can be manufactured into desired shapes using inexpensive materials, and costs can be further reduced.

(4) O between the transparent member 12 and the gear housing 1
Since the ring 11 is interposed so as to cover the working chamber 2, the sealing of the working chamber 2 can be completely maintained.

(5) Since the O-ring 11 serves as a cushion between the transparent member 12 and the gear housing 1,
This prevents the transparent member 12 from cracking during tightening.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing a non-circular gear type flowmeter which is an embodiment of the present invention, and Fig. 2 is a -
FIG. 3 is a partially omitted plan sectional view taken along the line, and FIG. 3 is a plan sectional view taken along the line -- in FIG. FIGS. 4 and 5 are partially enlarged sectional views showing conventional examples, respectively. 1... Gear housing, 2... Working chamber, 3...
Inlet passage, 4... Outlet passage, 5... Inlet pipe, 6... Outlet pipe, 7... Non-circular gear (rotating body), 8... Support shaft, 9... Reflector (reflecting surface), 10...Annular groove, 11...O ring, 1
2...Glass plate (transparent member), 13...Cushion, 14...Spacer, 15...Case,
16...Bolt, 17,18...Through hole, 19...
Light emitting element, 20... Light receiving element, 21... Input/output device.

Claims (1)

[Claims for Utility Model Registration] A gear housing 1 and a working chamber 2 formed to allow fluid to flow through the gear housing 1.
and a pair of non-circular gears 7, 7 which are respectively rotatably stored in the working chamber 2 and are meshed with each other.
A reflective surface 9 provided on one end surface of at least one non-circular gear 7 so as to rotate integrally with the reflective surface 9, and a light emitting element 19 and a light receiving element 20 respectively disposed so as to face the reflective surface 9. and a light emitting element 19 that reflects on a reflective surface 9 provided on the non-circular gear 7 that is rotated by the flow of the fluid.
By detecting the light with the light receiving element 20,
In a non-circular gear type flowmeter configured to measure a flow rate, an annular groove 10 is recessed in the end surface of the gear housing 1 on the side of the reflecting surface 9 so as to surround the opening of the working chamber 2. Additionally, an O-ring 11 is accommodated in this annular groove 10, and a transparent member 12 formed in a plate shape that covers the entire opening of the working chamber 2 is provided on the end face of the gear housing 1. The light emitting element 19 and the light receiving element 2 are pressed against and in contact with the ring 11.
0 is opposed to the reflective surface 9 with the transparent member 12 in between.