JPH028175Y2 - - Google Patents

Description

[Detailed description of the invention] The invention relates to a means for extracting to the outside the displacement of a valve body that moves up and down in response to flow rate fluctuations.
Our objective is to provide a highly reliable flow rate detection device that can operate stably without causing problems such as locking, changes in sliding resistance, or water leakage even during long-term use. It is something to do.

Conventionally, in this type of flow rate detection device, the displacement of a valve body that moves up and down in response to flow rate fluctuations has been extracted to the outside via a shaft.

FIG. 1 shows, as an example, a remote control unit used in a heat supply circulation device, etc.
Water flowing into the flow rate detection section 2 through the strainer 1 displaces the movable valve seat 3 and the valve body 4 that abuts it up and down depending on the flow rate. The valve body 4 has a valve stem 5
is fixedly provided, passes through the O-ring 6 and faces the outside, and is configured to open and close the micro switch 7 in response to displacement of the valve body. 8 is a differential pressure detection section.

The drawbacks of this conventional flow rate detection section are as follows.

(1) After long-term use, the sliding resistance between the shaft and O-ring increased significantly due to lubricant consumption and dust buildup. Furthermore, even at low temperatures, the O-ring becomes hard and the sliding resistance increases, causing errors in the detected flow rate or the shaft not moving, resulting in malfunction.

(2) Particularly when attempting to detect a small flow rate, it is not possible to provide a large amount of "squeezing" for the O-ring due to sliding resistance, resulting in water leakage even during short-term use.

(3) The O-ring's feeding action due to the shaft's reciprocating sliding, and the water that oozes out as the O-ring wears evaporates on the shaft, and scale later adheres to the shaft, preventing the shaft from moving. A so-called lock condition sometimes occurred.

There was also a structure in which the displacement of the valve body was converted from vertical displacement to rotational displacement of the shaft, and the rotating shaft was sealed with an O-ring, but the drawbacks were the same as those described above.

The present invention solves all of the above-mentioned drawbacks of the conventional art, and next, specific embodiments thereof will be described with reference to the drawings.

In FIGS. 2 and 3, a valve body 10 is provided inside a valve frame body 9 and is displaced up and down in response to an increase or decrease in flow rate. Reference numeral 11 denotes a weak spring that overcomes fluid resistance and pushes the valve body 10 downward when the flow rate becomes extremely low.

A shaft 12 is provided on the valve body 10, and the shaft 12 is engaged with one end of an arm 14 at the upper part thereof by a pin 15 through a guide portion 13 of the shaft. The arm 14 extends through the valve body wall 16 to face the outside, and is arranged such that the other end can come into contact with the micro switch 17.

The periphery of the penetrating portion of the valve casing wall 16 is supported by a support 18 that has a spherical surface and swings the valve casing wall, and the periphery is watertight to the valve casing wall 16 as a sealing means for shutting off the inside and outside. A diaphragm-shaped flexible membrane body A19 made of a plastic material such as rubber is provided, the center portion of which is fixed to the arm 14 in a watertight manner.

Next, to explain the operation, when the flow rate exceeds a predetermined value, the valve body 10 is lifted and the valve stem 12 is moved to the arm 1.
Push up 4. Since the arm 14 swings using the support 18 provided on the valve body as a fulcrum, the other end facing the outside moves downward, releasing the pressure on the micro switch 17 that had been pressed until then. Become. If this micro switch 17 is normally closed, the switch is turned ON. When the flow rate is gradually reduced from this state, the operation is opposite to that described above and returns to the original state. At this time, the flexible membrane A19, which is a means for sealing the inside and outside, is only slightly deformed because it is provided near the support 18, which is the fulcrum of the arm 14. In addition, even if the diaphragm 19 has a high rigidity due to strength issues or the pressing force of the micro switch 17 is large, the valve body can be fixed by increasing the arm length of the fulcrum and the valve stem locking part. 10 can be eliminated.

Similarly, by appropriately setting the arm length between the fulcrum and the valve shaft locking portion and between the fulcrum and the microswitch 17, the acting force and displacement on the microswitch 17 can be set arbitrarily. Moreover, since the seal support stage is provided near the fulcrum, the influence of the rigidity of this seal means is originally extremely small due to the lever principle.

Furthermore, since the flexible membrane body 19 serving as the sealing means does not displace in a direction perpendicular to the membrane surface like a conventional diaphragm, its diameter can be small, and it is less affected by internal pressure fluctuations inside the valve body. This small effect only causes the arm 14 to protrude a little in the axial direction, and does not affect the accuracy of flow rate detection at all.

As described above, the present invention extracts the displacement of the valve body, which moves up and down in response to flow rate fluctuations, to the outside via an arm that swings around the valve body penetration part as a fulcrum, and also makes the seal of the valve body penetration part plastic. Since the sealing means made of material is provided, the following effects are obtained.

There are no sliding parts because the arm is watertightly fixed to the valve body wall at the periphery at the valve body penetration part, and the center is sealed by a flexible membrane body that is watertightly fixed to the arm. Does not cause water leakage.

Since the flexible membrane body and the arm do not directly slide, the displacement of the valve body is extracted to the outside by swinging of the arm using the valve body penetration part as a fulcrum, so there is no dust on the arm part or the flexible membrane body part. Even if the flexible film is hardened due to temperature changes or other factors, the flow rate detection operation can be performed without any problem, and stable operation can be achieved over a long period of time.

Since there is no water leakage, there is no risk of the arm becoming stuck due to scale build-up.

By appropriately setting the distance between the fulcrum and the locking part of the arm, or the fulcrum and the microswitch, it is possible to arbitrarily set the acting force and displacement on the microswitch, corresponding to the displacement and rigidity of the flexible membrane. be. Also, unlike conventional diaphragms, displacement is not affected by internal pressure.

Note that the present invention can be applied not only to the flow rate detection device but also to the differential pressure detection section 8 described in the conventional example, if necessary.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional remote control unit having a flow rate detection section, Fig. 2 is a longitudinal sectional view of a flow rate detection device showing an embodiment of the present invention, and Fig. 3 is a section A of Fig. 2. It is an enlarged sectional view. 9... Valve body, 10... Valve body, 12... Shaft, 1
4, 14', 14'', 14...arm, 19...
Flexible membrane body A.

Claims (1)

[Scope of utility model registration request] A valve body is provided inside the valve body to be displaced in accordance with flow rate fluctuations, and this valve body or a shaft provided on the valve body is linked to one end of an arm, and this arm is passed through the valve body and attached to the other end. a flexible membrane body whose periphery is watertightly fixed to the valve casing wall and whose center part is watertightly fixed to the arm is provided on the valve casing penetrating portion of the arm; A flow rate detection device that detects the other end facing the outside with a displacement detector, and detects the vertical displacement of the valve body in response to flow rate fluctuations as the swinging displacement of the arm.