JP2000227356A - Float of liquid level indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a durable float of a liquid level indicator having a weld part of a sufficient strength to a pressure in constituting the spherical float by welding two semispheres. SOLUTION: Two float cases 1a and 1b of semispherical bodies are welded in a state with opening part sides being opposed to each other, thereby constituting a spherical body. A through pipe 12 for guide is set to the spherical body. The float of a liquid level indicator is thus formed. In this case, the opposed opening parts are formed to cut end faces of the semispherical bodies. The cut end faces are welded while being butted with each other, thereby constituting the spherical body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a float of a liquid level gauge, and more particularly to a float of a liquid level gauge excellent in high-pressure repetitive pressurization.

[0002]

2. Description of the Related Art A liquid level gauge having such a construction is mounted on, for example, a side of an oil separator provided on a discharge side of a compressor, and separates oil (lubricating oil) from a refrigerant by the oil separator. The oil level is monitored by a liquid level gauge, and a signal is issued when the oil level becomes equal to or more than a certain amount or equal to or less than a certain amount.

As shown in FIG. 5, a liquid level gauge G is
As described above, the refrigerant gas is provided to be connected to the oil separator OS on the discharge side of the compressor C of the refrigeration cycle, and the mixed gas of the refrigerant gas discharged from the compressor and the compressor oil, which is the lubricating oil, is separated by the oil separator. And oil is separator O
It is stored in S and returned to the compressor C through the oil return pipe B. On the other hand, the refrigerant gas from which the oil has been separated circulates to the condenser D. The level gauge G and the oil separator OS are connected by a refrigerant gas line K1 and an oil line K2. Refrigerant gas in the oil separator OS flows into the liquid level gauge G via the pipe K1, and the oil separator OS
The oil inside flows into the liquid level gauge G via the pipe K2. The oil from which the refrigerant and the oil have been separated is stored below the liquid level gauge G, and the float is floating above the liquid (on the oil).
The amount of oil in the level gauge G is detected according to the vertical movement of the float.

As shown in FIG. 6, a pipe 12 is provided at the center of a float case 11 for a float F0 disposed inside a liquid level gauge, and the pipe 12 is connected to a liquid level gauge (not shown). It is arranged so as to slide up and down from outside on a pipe passing through G. The retaining ring 2 is held on the pipe 12 so as to sandwich a magnet (permanent magnet) 21 from above and below.
0 is attached. In the float F0, flanges 11a1 and 11b1 are formed at openings of two hemispherical float cases 11a and 11b, respectively.
1a1 and 11b1 are welded to form a spherical float case 1
1 is formed.

In the liquid level gauge having such a configuration, when the liquid level in the liquid level gauge main body increases or decreases, the float F0 moves up and down along a pipe penetrating the liquid level gauge G, and the magnet 21 in the float F0 moves up and down. Therefore, when approaching a reed switch attached to a pipe penetrating the liquid level gauge G, it is turned on by magnetic force to monitor the oil amount.

[0006]

However, in the float shown in FIG. 6, the plate-like material is formed into a hemispherical shape with a flange by squeezing, and two hemispherical shapes are overlapped with each other and welded. Since it was formed into a spherical shape, it could not withstand the pressure (3.3 MPa) of the oil separator. For example, the weld between the pipe 12 that guides the float F0 up and down and the spherical surface has sufficient strength,
The welded portion between the flange portions (flange portions) 11a1 and 11b1 was insufficient in durability against repeated pressure.

Accordingly, an object of the present invention is to provide a durable float for a liquid level gauge, in which a welded portion has sufficient strength against pressure when two hemispheres are formed into a spherical float by welding. It is to be.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method of forming a spherical body by welding two hemispheres in a state where the opening sides of two float cases are opposed to each other. In a float of a liquid level gauge having a guide with a penetrating pipe attached to the form, the opposed opening is formed in the cut end face of the hemisphere, and the cut end face is welded in a state where the cut end faces abut each other to form a spherical body. Make up.

With the above structure, the shape of the butted portion of the hemispherical float case becomes gentle, and the stress applied to the spherical surface is also equal at the butted welded portion, and the stress concentration is greatly reduced, so that the repeated pressure durability is high. Become.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiments (examples). The parts already described are given the same reference numerals, and redundant description will be omitted.

(1) First Embodiment FIG. 1 is a sectional view and an enlarged view of a main part of a float F1 of this embodiment. As shown in FIG.
In the float case 1 constituting the first embodiment, the cut end surfaces of the upper and lower stainless steel hemispherical upper and lower float cases 1a and 1b are slightly extended along the center axis direction of the pipe 12 so as to form a whole elliptical shape ( The slender spheres) and the near portions 1a1 and 1b1 of the abutting portions (end face portions) are formed linearly. The butting portion is formed at right angles to the linear neighboring portions 1a1 and 1b1, and the butting portion is fixed by welding.

(2) Test and Experimental Results Next, the float F1 of the present embodiment configured as described above is used.
The test results and the experimental results of the above will be described.

(2-1) Repetitive pressure endurance / withstand pressure test FIG. 2 shows a test of repetitive pressure endurance / withstand pressure of the conventional product (with a flange, see FIG. 6) and the first embodiment (durability countermeasure product, see FIG. 1). It is a comparative table showing a result. As shown in FIG. 2, the float case of the conventional product has a plate thickness t: 0.2 mm, a diameter of a tip portion (weld portion) of the collar: 30.5 mm, and a pipe length L: 29 mm. The float case of the first embodiment (durable product, elongated spherical shape) has a plate thickness t: 0.25 mm, a diameter of a welded portion: 28 mm, and a pipe length L: 32.4 mm.
It is.

Test Items <Repeated pressure endurance> When a repeated pressure endurance test (standard 200,000 times) of 0.41 MPa and 3.3 MPa was carried out, the number of the conventional float cases was four (n = 4). )
Of those, 1/4 was NG (failed) by 40,000 repetitions
, And the total number was NG by 200,000 times. On the other hand, in the case of the float of the first embodiment, all of the five test samples (n = 5) passed all the samples up to the repetition number of 1.4 million times.

<Crush-Withstand Pressure> Standard of crack withstand pressure 4.95
With respect to 13 MPa, a pressure of 9.2 to 10 MPa was applied to 13 test samples (n = 13) as conventional products.
Both passed. Further, in the float case of the first example, when a pressure of 6.5 MPa was applied as an average value to 15 test articles (n = 15), all 15 test pieces passed.

<Float specific gravity> 0.77 (g /
cm3), and the product of the first embodiment is 0.74 (g / cm3).
Met. For this item, a smaller value is more preferable in view of the nature of the float. Also, in the float case of this embodiment,
Since the cut end faces of the hemisphere are welded to each other, it is preferable that the plate thickness is large from the viewpoint of welding strength. Therefore, the plate thickness of the conventional product was 0.2 mm, but was 0.25 mm in the present embodiment. However, simply increasing the plate thickness increases the weight and the specific gravity of the float. Therefore, an increase in the specific gravity of the float is suppressed by forming the pipe 12 as a vertically elongated slender sphere (see FIG. 1) along the center axis direction.

(2-2) Experimental Results FIG. 3 is a diagram showing the pressure-stress characteristics of the conventional product and the first embodiment. In this experiment, the float case of the first embodiment is durable.
It clarifies the reason why it is superior to conventional products in both aspects of withstand voltage.

As shown by a black square (■) in FIG.
Attach a strain gauge to the flat surface of the collar part of the conventional product, and apply pressure (M
The stress (N / mm2) when Pa) is applied is measured. Further, as shown by a black circle (●) and a black triangle (▲), strain gauges were attached to the welding surface and the spherical portion of the welded portion of the float case of the first embodiment, and pressure (MPa) was applied. The stress (N / mm2) at the time of the measurement is measured.

As a result, in the case of the conventional product (black square ■), the deformation in the compression direction is restricted at the time of pressurization, and a large concentrated stress is locally generated, so that the repeated pressure durability is low. Conceivable.

On the other hand, in the case of this embodiment, the following first
For the second reason, it is determined that the repeated pressure durability has been improved. The first reason is that the shape of the butted portion of the hemispherical float case is gentle, and the stress applied to the spherical surface is also equal at the butted welded portion, so that the stress concentration is greatly reduced. The second reason is that, in addition to the first reason, the plate thickness of stainless steel is set to 0.2 mm to 0.2 mm.
The point is that the durability to repeated pressure is further improved by increasing the thickness to 5 mm.

(3) Second Embodiment FIG. 4 is a sectional view and an enlarged view of a main part of a float F2 of this embodiment.

As shown in FIG. 4, the float F of this embodiment is
The float case 2 made of stainless steel is formed by joining the upper and lower hemispherical float cases 2a and 2b to form a complete spherical shape (spherical shape), and the vicinity portions 2a1 and 2b1 of the abutting portion (end face portion) are formed. Have a slightly curved shape. Then, the butting portion (end face portion) is formed so as to fit vertically, and the butting portion is fixed by welding.

A pressure resistance / durability test was also performed on the float case of the second embodiment. As in the case of the first embodiment, both the pressure durability and the crush resistance were satisfied.

In the description of the conventional example, the case where a reed switch and a permanent magnet are used for the configuration of the liquid level gauge has been described. However, for example, when a Hall element, a Hall IC, a magnetoresistive element, or the like is used, the present invention is also applicable. Of course, the invention can be applied.

[0025]

As described above, according to the present invention, the opposing openings are used as the cut end faces of the hemispheres, and the cut end faces are welded in a state where they abut each other to form a spherical body. The shape of the butted portion of the float case becomes gentle, and the stress applied to the spherical surface is also equal at the butt welded portion, stress concentration is greatly reduced,
A float of a liquid level gauge having excellent durability can be provided.

[Brief description of the drawings]

FIG. 1 shows a float according to a first embodiment of the present invention;
Is a sectional view thereof, and (b) is an enlarged view of a main part.

FIG. 2 is a table showing test results of a product of the first embodiment and a product of a conventional example.

FIG. 3 is a view showing pressure-stress characteristics of a product of the first embodiment and a product of a conventional example.

FIG. 4 shows a float according to a second embodiment of the present invention;
Is a sectional view thereof, and (b) is an enlarged view of a main part.

FIG. 5 is a schematic view showing a part of a refrigeration circuit including a conventional liquid level gauge.

6A and 6B show a float of a conventional liquid level gauge, in which FIG. 6A is a cross-sectional view and FIG. 6B is an enlarged view of a main part.

[Explanation of symbols]

 F1 Float of liquid level gauge according to first embodiment 1 Float case 1a, 1b Hemispherical float case 1a1, 1b1 Near portion of butted portion 12 Pipe 20 Retaining ring 21 Magnet

Continuation of the front page (72) Inventor Atsushi Sekiya 535 Sasai, Sayama City, Saitama Prefecture Sagimiya Manufacturing Co., Ltd. Sayama Works F-term (reference) 2F013 AA01 AB01 CA30

Claims (5)

[Claims] 1. A float of a liquid level gauge comprising two hemispherical float cases which are welded to each other in a state where the opening sides thereof are opposed to each other, and a penetrating pipe for guide is attached to the spherical bodies. 3. The float of claim 1, wherein the opposed openings are formed in cut end faces of the hemisphere, and the cut end faces are welded in a state where the cut end faces abut each other to form a spherical body. 2. The vicinity of the butted cut end surface is formed in a cylindrical shape in a central axis direction of the through pipe.
The float of the liquid level meter described. 3. The float of the liquid level gauge according to claim 2, wherein the cut end surface is formed at right angles to the cylindrical portion. 4. The float of the liquid level gauge according to claim 1, wherein the two float cases are formed of a stainless steel plate. 5. The float of the liquid level gauge according to claim 1, wherein a thickness of a stainless plate of the two float cases is formed to be 0.2 to 0.3 mm.