JP2005308103A - Pilot valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that, when a back pressure chamber 5 and a primary chamber 1 located on a back side of a control valve 3 in a pilot valve having the diaphragm type control valve 3 are filled with water, and water is frozen, the pressure in the back pressure chamber 5 is increased, a center portion of the control valve 3 facing a secondary chamber 2 is pressed from the back pressure chamber 5 side and broken. <P>SOLUTION: A pressure release unit 33 is integrally provided with a rubber-made seal part 31 provided on the control valve 3 so that the pressure in the back pressure chamber 5 is applied to the pressure release unit 33. Since the pressure release unit 33 is rubber-made similarly to the seal part 31, the pressure release unit 33 is swollen to the secondary chamber 2 side to mitigate the increase of the pressure even when the pressure in the back pressure chamber 5 is increased. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pilot valve equipped with a diaphragm type on-off valve that is built in a hot water supply device or the like and opens and closes a water supply passage.

  Referring to FIG. 4, this figure shows the periphery of a valve body 3 of this type of conventional pilot valve. The details of the operation including other parts of the pilot valve will be described later in “Best Mode for Carrying Out the Invention”.

  In this figure, 1 is a primary chamber, and tap water flows into this primary chamber from the water intake part 11. The primary chamber 1 is formed in an annular shape and surrounds the secondary chamber 2 located in the center. A diaphragm type valve element 3 is in contact with the opening 21 of the secondary chamber 2. The back pressure chamber 5 of the valve body is communicated with the primary chamber 1 via the valve closing passage 12. In the illustrated state, the valve body 3 blocks the opening 21. The internal pressure and the pressure in the primary chamber 1 are equal to each other.

  Since the pressure of the primary chamber 1 does not act on the central portion facing the secondary chamber 2 in the lower surface in the figure of the valve body 3, the force that pushes the valve body 3 upward from the primary chamber 1, that is, the valve opening direction. Further, the force that pushes the valve body 3 downward from the back pressure chamber 5 in the valve closing direction becomes larger. Therefore, the valve body 3 is pressed against the opening 21, and the opening 21 remains closed.

  In this state, when the back pressure chamber 5 is communicated with the secondary chamber 2 and the pressure of the back pressure chamber 5 is released, the force that has pushed the valve body 3 down from the back pressure chamber 5 side rapidly decreases. 3 is pushed up by the pressure in the primary chamber 1, is released from the opening 21, and the opening 21 is opened. Then, the water filled in the primary chamber 1 immediately flows out to the secondary chamber 2 through the opening 21.

  When the communication of the back pressure chamber 5 to the secondary chamber 2 is closed, the pressure in the primary chamber 1 propagates again through the valve closing passage 12 to the back pressure chamber 5, and the valve body 3 is pushed downward. The opening 21 is closed.

  In the valve body 3, a seal portion 31 and a diaphragm 32 that are in contact with the opening 21 to seal the opening 21 are integrally formed. The seal portion 31 and the diaphragm 32 are made of rubber having flexibility and high elastic deformation rate. A backup member 4 for backing up the seal portion 31 is attached to the back surface of the seal portion 31. The backup member 4 is configured so that it does not fall off from the seal portion 31 by being manually fitted into the central through hole of the seal portion 31 after the seal portion 31 and the diaphragm 32 are integrally formed. Since the backup member 4 needs to have rigidity, it is made of resin.

  In such a configuration, when the outside air temperature decreases while the back pressure chamber 5 is filled with water, the water in the back pressure chamber 5 is frozen. When water freezes, the volume expands by about 10%. At that time, if the primary chamber 1 is not filled with water, the expansion of the water in the back pressure chamber 5 can be absorbed by the diaphragm 32 being deformed. However, since the primary chamber 1 is usually filled with water, the diaphragm 32 is deformed and cannot absorb the expansion of the back pressure chamber 5. Therefore, when the water in the back pressure chamber 5 is frozen, the increase in the pressure in the back pressure chamber 5 due to the expansion of the water is caused especially in the central portion of the backup member 4 facing the secondary chamber 2. Act on.

As a result, the backup member 4 breaks from the position indicated by the crack line 4a in FIG. For the purpose of preventing breakage at the time of freezing, another member formed of a material having a large volume contraction rate having a large number of closed cells is attached in advance to the portion to be frozen, and when it is frozen, that member There is known one in which the increase in pressure is mitigated by contraction of the volume of (see, for example, Patent Document 1).
JP 2003-64263 A (FIGS. 1 and 4)

  For example, when the member described in Patent Document 1 is applied to the back pressure chamber 5 of the pilot valve, a member that alleviates the pressure rise must be set in the back pressure chamber. The volume of the pressure chamber must be increased by the volume of the member. For this reason, there arises a problem that the size of the pilot valve increases.

  In the conventional pilot valve, a through hole must be provided in the center of the seal portion 31 in order to attach the backup member 4. The operation of inserting the backup member 4 into the through hole provided in the seal portion 31 is performed manually. For this reason, when the backup member is not completely attached, there is a problem that water leaks through the through hole to the secondary chamber side, but the member described in Patent Document 1 is set in the back pressure chamber. However, such leakage cannot be prevented.

  In view of the above problems, an object of the present invention is to provide a pilot valve that can prevent a breakage accident during freezing without increasing the size of the pilot valve.

  In order to solve the above problems, a pilot valve according to the present invention includes an opening communicating with a secondary chamber and a primary chamber surrounding the opening, and is provided with a diaphragm type on-off valve capable of closing the opening, A valve closing passage that communicates the primary chamber with the back pressure chamber of the on-off valve, a valve opening passage that communicates the back pressure chamber with the secondary chamber, and an electromagnetic valve that opens and closes the valve opening passage is provided. In the pilot valve, the diaphragm-type on-off valve expands to the secondary chamber side due to the pressure rise in the back pressure chamber with the opening closed, and opens and closes the pressure relief portion that relieves the pressure rise in the back pressure chamber It was formed in the approximate center part of the valve.

  In the above configuration, even if the primary chamber is filled with water when the water in the back pressure chamber freezes, the secondary chamber is not filled because water is always discharged, and the pressure relief portion is the secondary chamber. Can expand to the side. Moreover, it is not necessary to set another member having a high contraction rate in the back pressure chamber as in the conventional patent document, so that the pilot valve does not increase in size.

  By the way, the on-off valve is provided with a rubber seal portion that abuts the periphery of the opening, and if the pressure relief portion is formed integrally with the seal portion, there is no need to provide a through hole in the seal portion. A water leakage accident when the valve is closed can be prevented.

  Further, if a hard backup member for backing up the seal portion is provided in the on-off valve so as not to be detachable, an assembly error due to manual work can be prevented.

  As is apparent from the above description, the present invention forms the pressure relief portion in the central portion of the on-off valve without setting a separate member in the back pressure chamber, so that the size of the pilot valve can be increased without increasing the size of the pilot valve. Damage accidents due to water freezing can be prevented.

  Referring to FIG. 1, the same reference numerals as those of the conventional structure shown in FIG. 4 described above are the same components and will not be described in detail.

  The water that has entered from the water inlet 11 enters the primary chamber 1. At this time, the pressure in the primary chamber 1 is 300 kPa to 500 kPa which is a feed water pressure. The pressure in the primary chamber 1 propagates from the primary chamber 1 to the back pressure chamber 5 via the valve closing passage 12 and the communication passage 13. Therefore, the opening / closing valve 3 is pressed by the opening 21 as described above, and the primary chamber 1 and the secondary chamber 2 are isolated from each other.

  An electromagnetic valve 6 is disposed between the valve closing passage 12 and the communication passage 13. The electromagnetic valve 6 includes a fixed core 61 and an electromagnetic coil 62 that excites the core 61. A mover 63 is attached between the core 61 via a spring 64. A valve element 65 is attached to the tip of the movable element 63, and the valve closing passage 12 and the communication passage 13 are isolated from the valve opening passage 22 by the biasing force of the spring 64.

  When the electromagnetic coil 62 is energized, the mover 63 is attracted to the core 61 against the biasing force of the spring 64, and the mover 63 moves to the left in the figure. Then, the back pressure chamber 5 is communicated with the valve opening passage 22 through the communication passage 13. Since the valve-opening passage 22 is connected to the secondary chamber 2, when the mover 63 moves to the left, the pressure in the back pressure chamber 5 rapidly decreases, and the on-off valve 3 moves upward to open. 21 is opened.

  When energization of the electromagnetic coil 62 is stopped, the attractive force between the core 61 and the mover 63 disappears. Therefore, the movable element 63 returns to the right by the biasing force of the spring 64, and the communication path 13 is blocked from the valve opening path 22. Then, the pressure in the primary chamber 1 propagates again from the valve closing passage 12 through the communication passage 13 to the back pressure chamber 5 and the on-off valve 3 closes the opening 21. Reference numeral 10 denotes a filter.

  Referring to FIG. 2, a diaphragm 32 exists around the on-off valve 3, and the seal portion 31 is formed integrally with the diaphragm 32. Both the diaphragm 32 and the seal portion 31 are molded by pouring rubber into the mold. In this embodiment, when the rubber raw material is filled in the mold, the resin backup member 4 is set in the mold, and the backup member 4 was cast into the rubber.

  The bottom part of the guide part 34 into which the guide G protruded into the back pressure chamber 5 is a pressure relief part 33. The pressure relief portion 33 is formed integrally with the seal portion 31. Therefore, the pressure relief portion 33 is molded of rubber in the same manner as the seal portion 31 and the diaphragm 32. As shown in the figure, the on-off valve 3 is seated on the opening 21, and the water in the back pressure chamber 5 is frozen while the opening 21 is closed, and the pressure in the back pressure chamber 5, in particular, the guide portion 34 increases. Then, the rubber pressure relief portion 33 expands to the secondary chamber 2 side and alleviates the pressure increase in the back pressure chamber 5. Since the pressure relief portion 33 is made of rubber, even if the pressure relief portion 33 is pushed from the back pressure chamber 5 side and greatly deformed, the pressure relief portion 33 does not break with respect to the seal portion 31.

  By the way, the form of the on-off valve 3 is not limited to that shown in FIG. For example, as shown in FIG. 3A, the backup member 4 may be bonded to the back side of the seal portion 31 without being cast into the rubber.

  Alternatively, as shown in FIG. 5B, a groove 41 is provided on the outer periphery of the backup member 4 and the groove 41 is filled with rubber so that the backup member 4 is not easily detached from the seal portion 31. Also good.

  Furthermore, as shown in FIG. 5C, a plurality of through holes 42 are formed in the backup member 4 and the rubber material before the effect is filled into the through holes 42 when the seal portion 31 is molded. However, the backup member 4 may be difficult to come off from the seal portion 42.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

The figure which shows the structure of one embodiment of this invention Diagram showing the vicinity of the on-off valve Diagram showing another form of on-off valve Diagram showing the structure of a conventional on-off valve

Explanation of symbols

1 Primary chamber 2 Secondary chamber 3 On-off valve 4 Backup member 5 Back pressure chamber

Claims (3)

  There is provided an opening communicating with the secondary chamber and a primary chamber surrounding the opening, and a diaphragm type on-off valve capable of closing the opening is provided, and the primary chamber is closed to communicate with the back pressure chamber of the on-off valve. A pilot valve provided with a valve passage and a valve opening passage for communicating the back pressure chamber with the secondary chamber, and provided with an electromagnetic valve for opening and closing the valve opening passage, wherein the diaphragm type opening and closing valve is opened The pilot is characterized in that a pressure relief part is formed in a substantially central portion of the on-off valve to expand to the secondary chamber side due to the pressure rise in the back pressure chamber while the valve is closed, and to relieve the pressure rise in the back pressure chamber valve.   2. The pilot valve according to claim 1, wherein the on-off valve is provided with a rubber seal portion that abuts on the periphery of the opening, and the pressure relief portion is formed integrally with the seal portion. The pilot valve according to claim 1 or 2, wherein a hard backup member for backing up the seal portion is provided on the on-off valve so as not to be attached or detached.

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