Water speed governor

Abstract

The present invention provides a water speed governor, which has: a valve seat (31) formed with a valve hole (31a) communicating a primary pressure chamber (301) and a secondary pressure chamber (302); a diaphragm (32) covering a surface of the secondary pressure chamber opposite to the valve seat; a valve body (33) disposed in the primary pressure chamber and opposed to the valve seat; and a helical spring (35) provided between a spring seat engaged with a flange portion at the front end of a valve shaft (331) extending from the valve body and the valve seat, the spring seat being in contact with the diaphragm, so as to prevent abnormal noise generated by vibration of the spring seat in a manner of contacting and separating from the diaphragm. A bag-shaped portion is provided on a surface of the spring seat opposite to the surface contacting the diaphragm, and the bag-shaped portion has: an end wall portion opposed to a surface of the flange portion facing the spring seat side; a peripheral wall portion surrounding the flange portion; and a bottom wall portion opposed to a surface of the flange portion facing the valve body side, and an axial hole through which an axial portion of the valve shaft passes is formed.

Description

Technical Field

[0001] The present invention relates to a water speed governor arranged in a water path in a water heater or the like. Background Art

[0002] Conventionally, as such a water speed governor, it is well known that it has: a valve seat formed with a valve hole communicating a primary pressure chamber on the upstream side and a secondary pressure chamber on the downstream side; a diaphragm covering the surface of the secondary pressure chamber opposite to the valve seat; a valve body disposed in the primary pressure chamber and facing the valve seat; a valve shaft extending from the valve body through the valve hole toward the diaphragm side; a spring seat mounted on the front end portion of the valve shaft; and a helical spring provided between the spring seat and the valve seat. By the pre-tightening force of the helical spring, the spring seat abuts against the diaphragm, and the valve body follows the displacement of the diaphragm via the spring seat and the valve shaft (for example, refer to Patent Document 1).

[0003] Refer to Figure 4 , the valve shaft 331 has: a flange portion 331a at the front end, and a shaft portion 331b having a diameter smaller than that of the flange portion 331a and located between the flange portion 331a and the valve body 33. The spring seat a in the above current example has a recessed portion b on the surface abutting against the diaphragm for the flange portion 331a to seat. And although not explicitly shown in Patent Document 1, a notch c is formed at one place in the circumferential direction of the spring seat a: from the recessed portion b to the outer peripheral edge of the spring seat a. The shaft portion 331b is inserted radially into the notch c so that the flange portion 331a seats in the recessed portion b. Thus, the spring seat a is mounted on the valve shaft 331 in a manner of engaging with the flange portion 331a to prevent detachment.

[0004] However, in the above conventional example, since the notch c is formed in the spring seat a, water flow is likely to penetrate between the diaphragm and the spring seat a through the notch c. And sometimes due to the influence of this water flow, the spring seat a vibrates in a manner of contacting and separating from the diaphragm, and abnormal sound occurs due to this vibration and resonance in the water path.

[0005] Patent Document

[0006] Patent Document 1: Japanese Utility Model Publication No. 6-10407 Summary of the Invention

[0007] The present invention has been completed in view of the above points, and its object is to provide a water speed governor capable of preventing abnormal sound caused by the vibration of the spring seat.

[0008] In order to solve the above problems, the water speed governor of the present invention is provided in a water passage and has: a valve seat formed with a valve hole that communicates a primary pressure chamber on the upstream side and a secondary pressure chamber on the downstream side; a diaphragm covering the surface of the secondary pressure chamber opposite to the valve seat; a valve body disposed in the primary pressure chamber and opposed to the valve seat; a valve shaft extending from the valve body through the valve hole toward the diaphragm side, having a flange portion at the front end and a shaft portion having a diameter smaller than that of the flange portion and located between the flange portion and the valve body; a spring seat mounted on the valve shaft in a manner that engages with the flange portion to prevent detachment; and a helical spring disposed between the spring seat and the valve seat. Due to the pre-tightening force of the helical spring, the spring seat abuts against the diaphragm, and the valve body follows the displacement of the diaphragm via the spring seat and the valve shaft. The water speed governor is characterized in that a bag-shaped portion is provided on the surface of the spring seat opposite to the surface abutting against the diaphragm and at a position radially inward of the abutting portion of the helical spring. The bag-shaped portion has: an end wall portion opposed to the surface of the flange portion facing the spring seat side; a peripheral wall portion surrounding the flange portion; and a bottom wall portion opposed to the surface of the flange portion facing the valve body side and formed with a shaft hole through which the shaft portion passes. An opening through which the flange portion and the shaft portion can be inserted radially is formed at one circumferential position of the peripheral wall portion and the bottom wall portion of the bag-shaped portion.

[0009] Advantages of the Invention

[0010] According to the present invention, even if water flows into the bag-shaped portion through the opening, since the surface of the bag-shaped portion on the diaphragm side is blocked by the end wall portion, the water flow will not enter between the spring seat and the diaphragm. Therefore, it is possible to prevent the spring seat from vibrating in a manner of contacting and separating from the diaphragm due to the influence of the water flow between them, and it is also possible to prevent the occurrence of abnormal sounds caused by this vibration.

[0011] In addition, in the present invention, it is preferable that the circumferential width of the opening formed in the bottom wall portion of the bag-shaped portion is smaller than the outer diameter of the shaft portion, and the shaft portion is received in the shaft hole while expanding the opening. Thereby, it is possible to elastically prevent the flange portion and the shaft portion from coming out of the bag-shaped portion through the opening to the outside in the radial direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a cutaway side view of a water supply system valve unit having a water speed governor according to an embodiment of the present invention.

[0013] Figure 2 is a perspective view of the state after separating the valve body and the spring seat of the water speed governor according to the embodiment.

[0014] Figure 3 is along Figure 1 The cross-sectional view taken along line III-III of

[0015] Figure 4 is a perspective view of the main part of a conventional example.

[0016] Explanation of Reference Numerals

[0017] 3... water speed governor, 301... primary pressure chamber, 302... secondary pressure chamber, 31... valve seat, 31a... valve hole, 32... diaphragm, 33... valve body, 331... valve shaft, 331a... flange portion, 331b... shaft portion, 34... spring seat, 341... bag-shaped portion, 342... end wall portion, 343... peripheral wall portion, 343a... opening, 344... shaft hole, 345... bottom wall portion, 345a... opening, 35... helical spring. Detailed Embodiment

[0018] Refer to Figure 1 Figure 1, the water supply system valve unit 1 is provided on the water path connected to the heat exchanger of the water heater. The water supply system valve unit 1 is configured such that in the valve housing 2 having an inlet 21 and an outlet 22, a water speed governor 3, a cylindrical water volume regulating valve 4, and a Venturi tube 5 are assembled in sequence from the upstream side. In addition, a drain plug 6 is installed in the valve housing 2.

[0019] The water speed governor 3 has: a valve seat 31 formed with a valve hole 31a that communicates the upstream primary pressure chamber 301 communicating with the inlet 21 and the downstream secondary pressure chamber 302; a diaphragm 32 covering the surface of the secondary pressure chamber 302 opposite to the valve seat 31; a valve body 33 disposed in the primary pressure chamber 301 and opposed to the valve seat 31; a valve shaft 331 extending from the valve body 33 through the valve hole 31a toward the diaphragm 32 side, and having a flange portion 331a at the front end and a shaft portion 331b having a diameter smaller than that of the flange portion 331a and located between the flange portion 331a and the valve body 33; a spring seat 34 installed on the valve shaft 331 in a manner of engaging with the flange portion 331a to prevent detachment; and a helical spring 35 provided between the spring seat 34 and the valve seat 31. And, by the pre-tightening force of the helical spring 35, the spring seat 34 abuts against the diaphragm 32, and the valve body 33 follows the displacement of the diaphragm 32 via the spring seat 34 and the valve shaft 331.

[0020] In addition, a cylindrical inner housing 36 is installed in the valve housing 2, and a primary pressure chamber 301 is partitioned and formed inside the inner housing 36. And, the primary pressure chamber 301 communicates with the inlet 21 via a communication hole 361 formed in the peripheral wall portion of the inner housing 36. The valve seat 31 is formed at the front end of the inner housing 36. In addition, inside the inner housing 36, a bypass chamber 303 is provided at the tail of the primary pressure chamber 301. And, a sub-valve seat 362 is provided on the inner peripheral surface of the peripheral wall portion of the inner housing 36, and the sub-valve seat 362 is formed with a sub-valve hole 362a that communicates the primary pressure chamber 301 and the bypass chamber 303.

[0021] Inside the valve body 33, there is provided a bypass passage 332 that connects the secondary pressure chamber 302 and the bypass chamber 303. In addition, a main valve portion 333 and a sub-valve portion 334 are formed on the outer periphery of the valve body 33. The main valve portion 333 seats on the valve seat 31 to block the valve hole 31a. When the main valve portion 333 approaches the valve seat 31 and reaches a distance below a specified value, the sub-valve portion 334 is inserted into the sub-valve hole 362a with a minute gap. And when blocking the valve hole 31a, the required amount of water throttled through the gap between the sub-valve portion 334 and the sub-valve seat 362 flows from the primary pressure chamber 301 to the secondary pressure chamber 302 via the bypass chamber 303 and the bypass passage 332, thereby buffering the sharp change in the water flow rate when the valve hole 31a is opened and closed.

[0022] On the back surface of the diaphragm 32, a back pressure chamber 322 is defined by a diaphragm cover 321. And during water flow, the negative pressure generated in the venturi tube 5 is introduced into the back pressure chamber 322 via the passage 51. In addition, a rod 323 with one end abutted against the diaphragm 32 is inserted through the diaphragm cover 321. During water flow, by introducing negative pressure into the back pressure chamber 322, the diaphragm 32 displaces toward the back pressure chamber 322 side, the rod 323 is pushed outward, and the gas valve for the burner that heats the heat exchanger is opened.

[0023] Refer to Figure 2 、 Figure 3 In the present embodiment, the spring seat 34 is made of resin. And on the surface of the spring seat 34 opposite to the surface abutting against the diaphragm 32, and at a position radially inward of the abutting portion of the helical spring 35, there is provided a bag-shaped portion 341 for receiving the flange portion 331a of the valve shaft 331. The bag-shaped portion 341 has an end wall portion 342 that faces the surface of the flange portion 331a facing the spring seat 34 side, a peripheral wall portion 343 that surrounds the flange portion 331a, and a bottom wall portion 345 that faces the surface of the flange portion 331a facing the valve body 33 side, and an axial hole 344 is formed through which the shaft portion 331b of the valve shaft 331 passes. In addition, at one circumferential position of the peripheral wall portion 343 and the bottom wall portion 345 of the bag-shaped portion 341, openings 343a and 345a are formed through which the flange portion 331a and the shaft portion 331b can be inserted from the radial direction.

[0024] The circumferential width of the opening 345a formed in the bottom wall portion 345 of the bag-shaped portion 341 is smaller than the outer diameter of the shaft portion 331b. And the shaft portion 331b is received in the axial hole 344 while expanding the opening 345a. Thus, it is possible to elastically prevent the flange portion 331a and the shaft portion 331b from detaching to the radially outer side through the openings 343a and 345a from the bag-shaped portion 341.

[0025] According to the present embodiment, even if water flows through the openings 343a and 345a and immerses into the bag-shaped portion 341, since the surface of the bag-shaped portion 341 on the diaphragm 32 side is blocked by the end wall portion 342, the water flow will not immerse between the spring seat 34 and the diaphragm 32. Therefore, it is possible to prevent the situation where the spring seat 34 vibrates in a manner of contacting and separating from the diaphragm 32 due to the influence of the water flow immersed between the spring seat 34 and the diaphragm 32, and it is also possible to prevent the occurrence of abnormal sounds caused by such vibration.

[0026] As described above, the embodiments of the present invention have been described with reference to the accompanying drawings. However, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

Claims

1. A water speed governor is provided in a water passage and has: a valve seat formed with a valve hole that communicates a primary pressure chamber on the upstream side and a secondary pressure chamber on the downstream side; a diaphragm that covers the surface of the secondary pressure chamber opposite to the valve seat; a valve body disposed in the primary pressure chamber and opposed to the valve seat; a valve shaft that extends from the valve body through the valve hole toward the diaphragm side and has a flange portion at the front end and a shaft portion with a diameter smaller than that of the flange portion and located between the flange portion and the valve body; a spring seat that is mounted on the valve shaft in a manner that engages with the flange portion to prevent detachment; and a helical spring provided between the spring seat and the valve seat. Due to the pre-tightening force of the helical spring, the spring seat abuts against the diaphragm, and the valve body follows the displacement of the diaphragm via the spring seat and the valve shaft. It is characterized in that On the surface of the spring seat opposite to the surface abutting against the diaphragm and at a position radially inward of the abutting portion of the helical spring, a bag-shaped portion is provided, and the bag-shaped portion has: an end wall portion that faces the surface of the flange portion facing the spring seat side; a peripheral wall portion that surrounds the flange portion; and a bottom wall portion that faces the surface of the flange portion facing the valve body side and is formed with a shaft hole through which the shaft portion passes. At a circumferential position of the peripheral wall portion and the bottom wall portion of the bag-shaped portion, an opening is formed through which the flange portion and the shaft portion can be inserted radially.

2. The water speed governor according to claim 1, characterized in that The circumferential width of the opening formed in the bottom wall portion of the bag-shaped portion is smaller than the outer diameter of the shaft portion, and the shaft portion is received in the shaft hole while expanding the opening.

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