JP2000179708A - Constant flow valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce fluid passing sound by forming the outer peripheral surface of a valve element into shape narrowed toward the tip side so as to be loosely fitted into a valve seat hole from the upstream side, and forming a clearance between the inner peripheral surface of the valve seat hole and the outer peripheral surface of the valve element as a flow control passage. SOLUTION: A valve element 4 is formed to be gradually reduced in diameter of the outer peripheral surface 4a toward the tip side. The valve element 4 is arranged to be loosely fitted into a valve seat 2b from the upstream side. As a result, a fluid passes through a narrow annular clearance A formed between the outer peripheral surface 4a of the valve element 4 and the inner peripheral surface of a valve seat hole 2b. Fluid pressure in a line 1a is gradually heightened, and when the area of a flow control passage A is narrowed, flow becomes constant regardless of the grade of differential pressure in an area with fixed differential pressure or more, but even in this case, fluid passing sound is extremely low since the flow control passage A is formed in narrow annular shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant flow valve which allows a fluid to flow at a constant flow rate regardless of a change in pressure of the fluid.

[0002]

2. Description of the Related Art In general, a constant flow valve is provided with a valve body which is biased from a downstream side to an upstream side in a pipe through which a fluid flows, and which is disposed downstream of the valve body against a biasing force. A flow control passage whose area is reduced as it moves to the side is formed.

FIG. 5 shows such a constant flow valve, in which a flow regulating hole 92 gradually widening to the downstream side in the form of an eight-shape is formed on the side wall of a valve body 91 formed in a bottomed cylindrical shape. The flow rate adjustment is performed by changing the area of a portion where the flow regulating hole 92 is located upstream of the valve seat 93. 94 is a compression coil spring for urging.

[0004]

However, when a fluid such as water passes through the eight-shaped flow regulating hole 92 as described above, a considerably large passing sound is generated, which is a problem as noise. May be.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a quiet constant flow valve which has a low sound passing through the fluid and does not become a noise source.

[0006]

In order to achieve the above-mentioned object, a flow rate detector according to the present invention comprises a valve disposed in a conduit through which a fluid is passed so as to be urged from a downstream side to an upstream side. A flow regulating passage whose area is reduced as the valve body moves downstream against the urging force is formed in the body, and the fluid passes through the flow regulating passage at a constant flow rate regardless of the pressure change of the fluid. In the constant flow valve, the outer peripheral surface of the valve body is
It is formed in a shape gradually narrowing toward the front side to be loosely fitted into the valve seat hole from the upstream side, and the gap between the inner peripheral surface of the valve seat hole and the outer peripheral surface of the valve body is flow-regulated. It is characterized by a passage.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a constant flow valve according to an embodiment of the present invention, for example, a pipe 1 through which a fluid such as water is passed.
A step portion 1c is provided in which the inner diameter of the downstream pipe 1b is made smaller than that of the upstream pipe 1a.

Reference numeral 2 denotes a valve seat block in which a through hole 2a having a circular cross section having substantially the same inner diameter as the downstream pipe 1b is formed at the axial position, and is fitted into the pipe 1 from the upstream side to form a step 1c.
Has been applied to.

Near the upstream end of the through hole 2a is a valve seat hole 2b.
The valve body 4 is disposed so as to be loosely fitted into the valve seat hole 2b from the upstream side, and between the outer peripheral surface 4a of the valve body 4 and the inner peripheral surface of the valve seat hole 2b. The fluid passes through a narrow annular gap A formed in the fluid.

In the valve element 4, the diameter of the outer peripheral surface 4a is on the front side (that is,
It is formed in a shape that gradually becomes narrower (downstream side). Therefore, when the insertion depth of the valve element 4 into the valve seat hole 2b is small, the area of the gap A through which the fluid passes increases, and as the insertion depth increases, the area A of the gap decreases, and the gap A regulates the flow rate of the fluid. It is a flow control passage.

From the tip of the valve body 4, for example, three legs projecting from the inner peripheral surface of the through hole 2a of the valve seat block 2 are formed so that the valve body 4 is inserted into the valve seat hole 2b. It does not fluctuate.

A support shaft 5 is loosely inserted from the upstream side into a hole formed at the axial position of the valve body 4 from the upstream side, thereby suppressing the valve body 4 from wobbling. The support shaft 5 is fixed to the valve seat block 2 via a supporter 5a formed like an octopus foot, and a filter 7 arranged around the valve body 4 in a cap shape is also fixed by the supporter 5a. .

A compression coil spring 6 is sandwiched in a compressed state between a flange 4 c formed in a flange shape at the upstream end of the valve body 4 and the valve seat block 2.
The valve body 4 is always urged toward the upstream side by the spring force.

In the constant flow valve of the embodiment configured as described above, the fluid pressure in the upstream pipeline 1a is low, and therefore, the differential pressure between the upstream pipeline 1a and the downstream pipeline 1b is small. At this time, as shown in FIG.
The flow control passage A protruding from b to the upstream side has a large area.

Then, as the fluid pressure in the pipeline 1a gradually increases, and thus the pressure difference between the upstream pipeline 1a and the downstream pipeline 1b increases, as shown in FIGS. The compression coil spring 6 is compressed corresponding to the differential pressure, and the valve element 4 is pushed into the valve seat hole 2b, and the area of the flow control passage A is reduced.

As a result, as shown in FIG. 4, in a region where the differential pressure is equal to or higher than a certain value, regardless of the magnitude of the differential pressure,
The flow rate of the fluid can be made constant (the outer peripheral surface 4a of the valve body 4 is formed into such a curved surface).

In the thus configured constant flow valve, since the flow control passage A is formed in a thin annular shape, the passing sound of the fluid is extremely small. According to the experiment, FIG.
It has been confirmed that the magnitude of the passing sound is reduced by about 3 to 8 dB as compared with the conventional constant flow valve shown in FIG. This is considered to be due to a smaller passing sound when the fluid passes through the narrow annular slit than when passing through the simple throttle hole.

[0018]

According to the present invention, the valve body is formed into a gradually tapering shape which gradually fits into the valve seat hole from the upstream side so as to gradually fit into the valve seat hole. Since the clearance between the outer peripheral surface of the body and the outer peripheral surface is a flow control passage, a quiet constant flow valve that does not become a noise generating source with a small sound of fluid passing can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a constant flow valve according to an embodiment of the present invention in a state where an upstream fluid pressure is small.

FIG. 2 is a longitudinal sectional view of the constant flow valve according to the embodiment of the present invention in a state in which the upstream fluid pressure is medium.

FIG. 3 is a longitudinal sectional view of the constant flow valve according to the embodiment of the present invention in a state where the upstream fluid pressure is large.

FIG. 4 is a characteristic diagram of the constant flow valve according to the embodiment of the present invention.

FIG. 5 is a vertical sectional view of a conventional constant flow valve.

[Explanation of symbols]

 A Flow control passage (gap) 1 Pipe line 2b Valve seat hole 4 Valve body 4a Outer peripheral surface 6 Compression coil spring

Claims (1)

[Claims] The present invention relates to a valve element which is urged from a downstream side to an upstream side in a pipe through which a fluid flows, and which moves toward the downstream side against the urging force. Accordingly, in a constant flow valve in which a flow control passage having a reduced area is formed, and a fluid flows through the flow control passage at a constant flow rate regardless of a change in pressure of the fluid, an outer peripheral surface of the valve body is provided with a valve seat hole. The shape is gradually narrowed toward the front side to be loosely fitted from the upstream side, and the gap between the inner peripheral surface of the valve seat hole and the outer peripheral surface of the valve body is defined as the flow control passage. A constant flow valve characterized in that: