Gas governor

Abstract

To provide a gas governor which can suppress governor noise without increasing the number of components and can also prevent secondary gas pressure from becoming unstable.SOLUTION: In a secondary pressure chamber 14 of a gas governor, a sub-chamber 14b which is partitioned by a bulkhead 141 from a main chamber 14a, which is a portion of the secondary pressure chamber facing a valve seat 15, is arranged . The sub-chamber 14b is in communication with the main chamber 14a via a communication path 14c. The bulkhead 141 is arranged at a position separated from a flow-out port forming portion which is a peripheral wall portion of the secondary pressure chamber 14 with a flow-out port 12 opened therein in a circumferential direction so that a distance from a valve port 16 of an end part 141a of the peripheral wall 141 on the side closer at least to the valve seat 15 and a curvature in the circumferential direction are equivalent to those of an end part 142a of the flow-out forming portion on the side closer to the valve seat 15.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gas governor provided in a gas supply passage for a gas burner.

Background Art

[0002] Originally, this type of gas governor has a casing having an inlet, an outlet, a primary pressure chamber communicating with the inlet, a secondary pressure chamber communicating with the outlet, a valve seat between the primary pressure chamber and the secondary pressure chamber, a diaphragm facing the primary pressure chamber on the side opposite to the valve seat, and a governor valve having a valve body portion inserted through a valve port formed in the valve seat and having an outer diameter gradually increasing toward the end on the secondary pressure chamber side. Then, the shaft portion of the governor valve extending from the valve body portion toward the diaphragm side is connected to the diaphragm, and the governor valve is displaced via the diaphragm according to the gas pressure fluctuation in the primary pressure chamber, so as to suppress the fluctuation of the gas pressure in the secondary pressure chamber, that is, the fluctuation of the secondary gas pressure.

[0003] By the way, in the gas governor as described above, the governor valve vibrates due to an external impact or the like, and the valve body portion abuts against the valve seat due to this vibration to become a sound source. Due to the resonance effect caused by the coincidence of the frequency of this sound source and the natural vibration frequency of the secondary pressure chamber, so-called governor noise may occur. Therefore, conventionally, there is known a device provided with a cylindrical weight that is externally inserted in the axial direction so as to be freely movable on the shaft portion of the governor valve (see, for example, Patent Document 1). In this device, the vibration of the governor valve can be attenuated by the vibration of the cylindrical weight in the opposite phase, and the governor noise can be suppressed. However, in this device, a cylindrical weight is required, and there is a problem of cost increase due to an increase in the number of parts.

[0004] Also, conventionally, there is known a device in which the peripheral wall portion of the secondary pressure chamber is recessed outward at a portion other than the portion where the outlet is provided, the volume of the secondary pressure chamber is enlarged, and the natural vibration frequency of the secondary pressure chamber is shifted from the frequency of the sound source, thereby suppressing the governor noise. In this device, the number of parts does not increase, which is advantageous for cost reduction.

[0005] However, it was found that this design causes the following problems. Specifically, the gas flow passing through the gap between the valve body and valve seat of the governor valve slows down on the recessed side of the circumferential wall relative to the outlet side. Furthermore, vortices are generated within the recessed space of the circumferential wall, and the influence of these vortices extends to the vicinity of the valve body of the governor valve, causing the gas flow passing through the gap to become uneven in the circumferential direction. As a result, the opening and closing operation becomes irregular, such as the valve body of the governor valve opening and closing at an angle, and the secondary gas pressure becomes unstable. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-159654 [Overview of the project] [Problems that the invention aims to solve]

[0007] In view of the above, the object of the present invention is to provide a gas governor that can suppress governor noise without increasing the number of parts, and also prevent the secondary gas pressure from becoming unstable. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides a gas governor comprising a casing having an inlet and an outlet, a primary pressure chamber communicating with the inlet, a secondary pressure chamber communicating with the outlet, and a valve seat between the primary and secondary pressure chambers, a diaphragm facing the primary pressure chamber on the opposite side of the valve seat, and a governor valve having a valve body inserted through a valve opening in the valve seat and having an outer diameter that gradually increases toward the end on the secondary pressure chamber side, wherein the shaft portion of the governor valve extending from the valve body toward the diaphragm is connected to the diaphragm, and the governor valve is displaced via the diaphragm in response to gas pressure fluctuations in the primary pressure chamber to suppress gas pressure fluctuations in the secondary pressure chamber, wherein the secondary pressure chamber is provided with a sub-chamber separated by a partition wall from the main chamber, which is the part of the secondary pressure chamber facing the valve seat, the sub-chamber is connected to the main chamber via a connecting passage, and the partition wall is the peripheral wall portion of the secondary pressure chamber where the outlet is openedDistant from the circumferential direction The partition wall is positioned such that the distance from the valve opening and the circumferential curvature of at least the end of the partition wall closer to the valve seat are the same as those of the end of the outlet opening closer to the valve seat.

[0009] According to the present invention, a sub-chamber is provided in the secondary pressure chamber, separated from the main chamber by a partition wall and communicating with the main chamber via a connecting passage. As a result, the natural frequency of the secondary pressure chamber increases and deviates from the frequency of the sound source mentioned above. Therefore, governor noise can be suppressed without increasing the number of parts due to the addition of a cylindrical weight. Furthermore, since the distance from the valve opening and the circumferential curvature of the end of the partition wall near the valve seat are the same as those of the end of the outlet opening near the valve seat, the gas flow passing through the gap between the valve body and the valve seat of the governor valve becomes uniform around the entire circumference. As a result, irregular opening and closing operations, such as the valve body of the governor valve opening and closing at an angle, do not occur, and the secondary gas pressure does not become unstable.

[0010] Furthermore, in the present invention, the communication passage may be formed as a gap between a lid that closes the end face of the secondary pressure chamber opposite to the valve seat and the lid-side edge of the partition wall, or this gap may be closed and the communication passage may be formed as a through-hole formed in the partition wall.

[0011] Furthermore, when the communication passage is formed by the gap between the lid and the lid-side edge of the partition wall, it is desirable that the position of the lid-side edge of the partition wall be closer to the lid than the position of the lid-side edge of the outlet. This prevents the influence of vortices generated in the sub-chamber from reaching the vicinity of the valve body of the governor valve, thereby stabilizing the secondary gas pressure. [Brief explanation of the drawing]

[0012] [Figure 1] A cross-sectional side view of a proportional valve device with a gas governor configured using the first embodiment of the present invention. [Figure 2] Cross-sectional view taken along the line II-II in Figure 1. [Figure 3] A cross-sectional side view of a proportional valve device with a governor, configured using the gas governor of the second embodiment of the present invention. [Figure 4]Cross-sectional view taken along the line IV-IV in Figure 3. [Modes for carrying out the invention]

[0013] Figure 1 shows a proportional valve device with a governor configured using a gas governor A according to an embodiment of the present invention. The gas governor A is installed in the gas supply path to the gas burner and comprises a casing 1 having an inlet 11 opening on one lower side, an outlet 12 opening on the other upper side, a primary pressure chamber 13 communicating with the inlet 11, a secondary pressure chamber 14 located above the primary pressure chamber 13 and communicating with the outlet 12, and a valve seat 15 between the primary pressure chamber 13 and the secondary pressure chamber 14. The valve seat 15 has a valve port 16 that connects the primary pressure chamber 13 and the secondary pressure chamber 14.

[0014] Furthermore, the gas governor A includes a diaphragm 2 facing the primary pressure chamber 13 on the opposite side of the valve seat 15, i.e., the lower side, and a governor valve 3 connected to the diaphragm 2. In addition, an electromagnetic solenoid 4 is provided to press the governor valve 3 upward to the opening side in order to constitute a proportional valve device. The outer circumference of the diaphragm 2 is clamped and fixed to the lower outer circumference of the primary pressure chamber 11 by a retaining plate 21 fastened to the lower surface of the casing 1. A back pressure chamber 22 that is open to the atmosphere is defined between the diaphragm 2 and the retaining plate 21. A cylindrical valve holder 24 is also provided on the lower side of the diaphragm 2, which has a flange portion 24a at its upper end that contacts the lower surface of the diaphragm 2 via a washer 23.

[0015] The governor valve 3 is inserted into the valve port 16 and has an umbrella-shaped valve body 31 whose outer diameter gradually increases toward the end on the secondary pressure chamber 14 side, i.e., the upper end, and a shaft 32 that extends downward from the valve body 31 and is connected to the diaphragm 2. A small-diameter shaft portion 32a is provided at the lower end of the shaft portion 32, protruding downward from the shoulder surface that contacts the upper surface of the diaphragm 2. The governor valve 3 is connected to the diaphragm 2 by fitting and fixing this small-diameter shaft portion 32a to the valve holder 24 through a hole formed in the center of the diaphragm 2. The governor valve 3 is also provided with a sub-shaft portion 33 that extends upward from the valve body 31 on the opposite side of the diaphragm 2, i.e., upward. The sub-shaft portion 33 abuts against the cover 17 that covers the end face of the secondary pressure chamber 14 opposite to the valve seat 15, i.e., the upper end face, thereby restricting the stroke of the governor valve 3 in the opening direction.

[0016] The electromagnetic solenoid 4 includes a yoke 41 attached to the lower surface of the retaining plate 21, a coil 43 wound around a bobbin 42 inside the yoke 41, a plunger 45 inserted through a cylindrical guide 44 on the inner circumference of the bobbin 42 so as to be movable vertically, and a spring 46 that biases the plunger 45 upward to cancel the weight of the plunger 45 and the governor valve 3. The plunger 45 abuts against the lower end of the small-diameter shaft portion 32a of the governor valve 3 and presses the governor valve 3 upward to the open side with a pressing force proportional to the current value supplied to the coil 43. As the current value increases, the governor valve 3 is displaced to the open side, the gap (opening degree) between the circumferential surface of the valve port 16 and the valve body portion 31 increases, and the gas pressure in the secondary pressure chamber 12, i.e., the secondary gas pressure, increases. Therefore, the amount of gas supplied to the gas burner changes in proportion to the current value. Furthermore, when the gas pressure in the primary pressure chamber 11, i.e., the primary gas pressure, fluctuates, the governor valve 3 is displaced via the diaphragm 2, changing its opening to absorb the gas pressure fluctuation, thereby suppressing fluctuations in the secondary gas pressure. As a result, even if fluctuations occur in the primary gas pressure, the secondary gas pressure is maintained at a predetermined pressure corresponding to the current value.

[0017] Incidentally, external impacts or other triggers can cause the governor valve 3 to vibrate, and this vibration causes the valve body 31 to come into contact with the valve seat 15, creating a sound source. Then, the resonance effect caused by the frequency of this sound source matching the natural frequency of the secondary pressure chamber 14 can produce noise known as governor noise. Therefore, in this embodiment, a sub-chamber 14b is provided in the secondary pressure chamber 14, separated from the main chamber 14a, which is the part of the secondary pressure chamber 14 that the valve seat 15 faces, by a partition wall 141, and this sub-chamber 14b is connected to the main chamber 14a via a connecting passage 14c. The connecting passage 14c is formed by the gap between the lid 17 and the edge of the partition wall 141 on the lid 17 side, i.e., the upper edge.

[0018] By providing a sub-chamber 14b in the secondary pressure chamber 14 in this way, the natural frequency of the secondary pressure chamber 14 increases and deviates from the frequency of the sound source mentioned above. Therefore, governor noise can be suppressed without increasing the number of parts due to the addition of the cylindrical weight as in the conventional example, which is advantageous in terms of cost reduction.

[0019] Also, referring to Figure 2, the partition wall 141 is positioned circumferentially away from the outlet opening portion 142, which is the peripheral wall portion of the secondary pressure chamber 14 in which the outlet 12 is opened. The distance from the valve opening 16 and the circumferential curvature of at least the end 141a of the partition wall 141 closer to the valve seat 15, and the end 142a of the outlet opening portion 142 closer to the valve seat 15 are the same as those of the end 142a of the outlet opening portion 142. In this embodiment, the circumferential center of the partition wall 141 is circumferentially 180° away from the circumferential center of the outlet opening portion 142. In addition, a partition wall 143 is provided in the circumferential middle of the sub-chamber 14b, dividing the sub-chamber 14b in two. However, this partition wall 143 can be omitted as in the second embodiment described later.

[0020] By making the distance from the valve opening 16 and the circumferential curvature of the end 141a of the partition wall 141 near the valve seat 15 the same as the end 142a of the outlet opening portion 142 near the valve seat 15, the gas flow passing through the gap between the valve body 31 and the valve seat 15 of the governor valve 3 becomes uniform around the entire circumference. As a result, irregular opening and closing operations such as the valve body 31 opening and closing at an angle are prevented, and the secondary gas pressure does not become unstable.

[0021] By the way, when the communication passage 14c is formed by the gap between the lid body 17 and the upper edge of the partition wall 141, the influence of the vortex generated in the sub chamber 14b reaches the outlet 12 through the main chamber 14a from the communication passage 14c. And when the position of the upper edge of the partition wall 141 is low, the turbulent flow due to the influence of the vortex flowing from the communication passage 14c toward the outlet 12 may reach the vicinity of the valve body portion 31 of the governor valve 3, which may cause instability of the secondary gas pressure.

[0022] Therefore, in the present embodiment, the position of the upper edge of the partition wall 141 is set above, that is, closer to the lid body 17 than the end on the lid body 17 side of the outlet 12, that is, the upper end position. According to this, it is possible to prevent the turbulent flow due to the influence of the vortex flowing from the communication passage 14c toward the outlet 12 from reaching the vicinity of the valve body portion 31 of the governor valve 3, and the stabilization of the secondary gas pressure can be achieved.

[0023] Next, the second embodiment shown in FIGS. 3 and 4 will be described. The basic structure of the second embodiment is not particularly different from that of the first embodiment, and the same members and parts as those in the first embodiment are given the same reference numerals as above. The difference between the second embodiment and the first embodiment is that the upper edge of the partition wall 141 is brought into close contact with the lid body 17 through the sealing member 171 to close the gap between the lid body 17 and the upper edge of the partition wall 141, and the communication passage 14c that connects the sub chamber 14b to the main chamber 14a is constituted by a through hole 141b having a relatively small diameter (for example, a diameter of 1 to 2 mm) formed in the partition wall 141, and the partition wall 143 of the first embodiment that divides the sub chamber 14b into two is omitted. Even in the second embodiment, the same operational effects as those in the first embodiment can be obtained.

[0024] In addition, the through hole 141b is formed by a tool inserted through the outlet 12 after the valve casing 1 is molded. Therefore, the position of the through hole 141a is below the position of the upper end of the outlet 12. However, if the through hole 141b has a small diameter, the influence of the vortex in the sub chamber 14b will not reach the inside of the main chamber 14a, and the secondary gas pressure will not become unstable due to the influence of the vortex.

[0025] Although embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the circumferential angle between the circumferential center of the outlet opening portion 142 and the circumferential center of the partition wall 141 is set to 180°, but it is also possible to set this circumferential angle to an angle other than 180°, for example, 150°. Also, in the above embodiment, the primary pressure chamber 13 is located at the bottom and the secondary pressure chamber 14 is located at the top, but it is also possible to invert the configuration so that the primary pressure chamber 13 is at the top and the secondary pressure chamber 14 is at the bottom. Furthermore, although the above embodiment applies the present invention to a gas governor that constitutes a proportional valve device with an electromagnetic solenoid 4, the present invention can be similarly applied to a normal gas governor that does not have an electromagnetic solenoid 4. [Explanation of Symbols]

[0026] A...Gas governor, 1...Casing, 11...Inlet, 12...Outlet, 13...Primary pressure chamber, 14...Secondary pressure chamber, 14a...Main chamber, 14b...Sub-chamber, 14c...Connecting passage, 141...Partition, 141a...End of partition near valve seat, 141b...Through hole, 142...Outlet opening, 142a...End of outlet opening near valve seat, 15...Valve seat, 16...Valve opening, 17...Cover, 2...Diaphragm, 3...Governor valve, 31...Valve body, 32...Shaft.

Claims

1. A gas governor comprising a casing having an inlet and an outlet, a primary pressure chamber communicating with the inlet, a secondary pressure chamber communicating with the outlet, and a valve seat between the primary and secondary pressure chambers, a diaphragm facing the primary pressure chamber on the opposite side of the valve seat, and a governor valve having a valve body inserted through a valve opening in the valve seat and having an outer diameter that gradually increases toward the end facing the secondary pressure chamber, wherein the shaft portion of the governor valve extending from the valve body toward the diaphragm is connected to the diaphragm, and the governor valve is displaced via the diaphragm in response to gas pressure fluctuations in the primary pressure chamber to suppress gas pressure fluctuations in the secondary pressure chamber, A gas governor characterized in that a secondary pressure chamber is provided with a sub-chamber separated by a partition wall from the main chamber, which is the portion of the secondary pressure chamber facing the valve seat, the sub-chamber is in communication with the main chamber via a connecting passage, and the partition wall is located in a portion circumferentially away from the outlet opening portion, which is the peripheral wall portion of the secondary pressure chamber where the outlet is opened, and the distance from the valve opening and the circumferential curvature of at least the end of the partition wall closer to the valve seat are the same as those of the end of the outlet opening portion closer to the valve seat.

2. The gas governor according to claim 1, characterized in that the communication passage is composed of a gap between a lid that closes the end face of the secondary pressure chamber opposite to the valve seat and the lid-side edge of the partition wall.

3. The gas governor according to claim 2, characterized in that the position of the end edge of the partition wall on the lid side is closer to the lid than the position of the end of the outlet on the lid side.

4. The gas governor according to claim 1, characterized in that the gap between the lid that closes the end face of the secondary pressure chamber opposite to the valve seat and the lid-side edge of the partition wall is closed, and the communication passage is composed of a through hole formed in the partition wall.

Images