Gas Governor

Abstract

To enable a gas governor to effectively prevent a governor noise by damping not only the axial direction vibration but also the radial direction vibration of a governor valve 3, the gas governor being provided with a governor valve 3 comprising a valve element 31 inserted into a valve hole 14 formed in a valve seat 13 disposed between a primary pressure chamber 11 and a secondary pressure chamber 12, with a first shaft 32 of the governor valve 3 extended from the valve element 31 and linked to a diaphragm 2 facing the primary pressure chamber 11 at the opposite side of the valve seat 13.SOLUTION: A cylindrical spindle 5 is idly and externally fitted in the axial direction to a first shaft 32 of a governor valve 3 or to a second shaft 33 thereof extended in the direction opposite to the first shaft with a gap apart therebetween, and a ring seat face 6 whereon the cylindrical spindle 5 can be seated by its own weight, is provided in the governor valve 3. A plurality of protrusions 61 are each provided on either of a ring seat face 6 and the bottom face of the cylindrical spindle 5, with each of the protrusions positioned only on a partial section disposed in the peripheral direction. The protrusions 61 are each made to contact the other of the ring seat face 6 and the bottom face of the cylindrical spindle 5, so that the cylindrical spindle 5 is supported on the ring seat face 6 in a state of tilting from the upright posture.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas governor to be installed in a gas supply path to a gas burner. [Background technology]

[0002] Originally, this type of gas governor includes a casing having a primary pressure chamber, a secondary pressure chamber above or below the primary pressure chamber, and a valve seat between the primary and secondary pressure chambers, a diaphragm facing the primary pressure chamber on the side opposite the valve seat, and a governor valve inserted into a valve hole formed in the valve seat and having a valve disc portion whose outer diameter gradually increases toward the end facing the secondary pressure chamber. A first shaft portion of the governor valve extending from the valve disc portion toward the diaphragm is connected to the diaphragm, and the governor valve is displaced via the diaphragm in response to fluctuations in gas pressure in the primary pressure chamber, thereby suppressing fluctuations in gas pressure in the secondary pressure chamber.

[0003] In gas governors such as those described above, an external impact or the like can cause the governor valve to vibrate, causing the valve disc to hit the valve seat and generating a noise known as governor whine. To address this issue, a known governor valve has been proposed in which a cylindrical weight is fitted onto either the second or first shaft of the governor valve, which extends from the valve disc toward the opposite side from the diaphragm, with a gap between them, allowing free axial movement, and the governor valve is provided with an annular seat on which the cylindrical weight can seat under its own weight (see, for example, Patent Document 1). This damps the axial vibration of the governor valve with the axial vibration of the cylindrical weight in the opposite phase, thereby suppressing governor whine to some extent.

[0004] However, it was discovered that the cause of governor noise was not only the axial vibration of the governor valve, but also the radial vibration (lateral vibration) of the governor valve, with the connection point to the diaphragm as the fulcrum. The above-mentioned conventional example was unable to attenuate the radial vibration of the governor valve, and was not able to sufficiently suppress governor noise. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-159654 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, an object of the present invention is to provide a gas governor that can damp not only axial vibration but also radial vibration of a governor valve, thereby effectively suppressing governor noise. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a governor valve comprising a casing having a primary pressure chamber, a secondary pressure chamber above or below the primary pressure chamber, and 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 valve body portion inserted into a valve hole formed in the valve seat and having an outer diameter gradually increasing toward the end portion on the secondary pressure chamber side, wherein a first 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 fluctuations in gas pressure in the primary pressure chamber, thereby controlling the pressure in the secondary pressure chamber. a cylindrical weight that is fitted onto a second or first shaft portion of a governor valve extending from a valve body portion on the side opposite to a diaphragm with a gap therebetween so as to be freely movable in the axial direction, and the governor valve is provided with an annular seat on which the cylindrical weight can be seated by its own weight, and a convex portion is provided on one of the annular seating surface and a lower end face of the cylindrical weight, positioned only at a portion of the circumference, and the convex portion comes into contact with the other of the annular seating surface and the lower end face of the cylindrical weight, so that the cylindrical weight is supported on the annular seating surface in a tilted state from an upright position.

[0008] According to the present invention, the lower end of the cylindrical weight is lifted from the annular seating surface between the protrusion and the portion of the cylindrical weight that contacts the annular seating surface on the circumferentially opposite side of the protrusion. This makes the cylindrical weight unstable and allows it to easily swing in the radial direction. As a result, not only can the axial vibration of the governor valve be damped by the axial vibration of the cylindrical weight in the opposite phase, but the radial vibration of the governor valve can also be damped by the radial vibration of the cylindrical weight in the opposite phase, thereby effectively suppressing governor whine.

[0009] Incidentally, if there is only one protrusion, the cylindrical weight becomes too unstable, and the cylindrical weight may swing radially even during normal operation when governor noise is not occurring, potentially causing instability in the gas pressure in the secondary pressure chamber. Therefore, in the present invention, it is desirable that a plurality of protrusions are provided circumferentially spaced apart in a portion of the circumference of one of the annular seating surface and the lower end face of the cylindrical weight, and that the central angle of the circumferential width between the contact portions of two protrusions on both sides of the circumferential direction with the other of the annular seating surface and the lower end face of the cylindrical weight is set to 30° to 60°. In this way, as will be described later, the cylindrical weight will swing radially under conditions that cause governor noise, but under normal circumstances, the cylindrical weight can be supported in a moderately unstable state so that it does not swing radially.

[0010] Furthermore, in the present invention, when a convex portion is provided on the annular seating surface, the convex portion is preferably provided so as to extend from the inner peripheral edge to the outer peripheral edge of the annular seating surface, so that even if the position of the cylindrical weight is shifted in the radial direction, the lower end of the cylindrical weight will not come off the convex portion, and the effect of damping radial vibration of the governor valve can be reliably obtained. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a governor-equipped proportional valve device configured using a gas governor according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional plan view taken along line II-II in FIG. [Figure 3] FIG. 4 is a cross-sectional view of a governor-equipped proportional valve device configured using a gas governor according to a second embodiment of the present invention. [Figure 4] FIG. 4 is an enlarged cross-sectional plan view taken along line IV-IV in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1, reference numeral A denotes a proportional valve device with a governor configured using a gas governor according to an embodiment of the present invention. This proportional valve device A is installed in a gas supply passage to a gas burner and includes a casing 1 having a primary pressure chamber 11 communicating with a gas inlet 11a, a secondary pressure chamber 12 located above the primary pressure chamber 11 and communicating with a gas outlet 12a, and a valve seat 13 between the primary pressure chamber 11 and the secondary pressure chamber 12. A valve hole 14 connecting the primary pressure chamber 11 and the secondary pressure chamber 12 is formed in the valve seat 13.

[0013] The proportional valve device A also includes a diaphragm 2 facing the primary pressure chamber 11 on the side opposite to the valve seat 13, i.e., on the lower side, a governor valve 3 connected to the diaphragm 2, and an electromagnetic solenoid 4 that presses the governor valve 3 upward to open it. The outer periphery of the diaphragm 2 is clamped and fixed to the outer periphery of the lower surface of the primary pressure chamber 11 by a presser plate 21 fastened to the underside of the casing 1. A back pressure chamber 22 that is open to the atmosphere is defined between the diaphragm 2 and the presser plate 21. A cylindrical valve holder 24 is also provided below the diaphragm 2, and has an upper flange 24a that contacts the underside of the diaphragm 2 via a washer 23.

[0014] The governor valve 3 is inserted through the valve hole 14 and has an umbrella-shaped valve disc 31 whose outer diameter gradually increases toward the end on the secondary pressure chamber 12 side, i.e., the upper end, and a first shaft 32 that extends downward from the valve disc 31 and is connected to the diaphragm 2. A small-diameter shaft 32a protrudes from the lower end of the first shaft 32, projecting downward from a 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 the small-diameter shaft 32a to the valve holder 24 through a hole formed in the center of the diaphragm 2. The governor valve 3 also has a second shaft 33 that extends upward from the valve disc 31 on the opposite side from the diaphragm 2. The second shaft 33 abuts against the cover plate 12b that covers the upper surface of the secondary pressure chamber 12, thereby restricting the stroke of the governor valve 3 in the opening direction.

[0015] The electromagnetic solenoid 4 includes a yoke 41 attached to the underside of the retaining plate 21, a coil 43 wound around a bobbin 42 inside the yoke 41, a plunger 45 inserted into a cylindrical guide 44 around the inner periphery of the yoke 41 so as to be movable up and down, and a spring 46 that urges the plunger 45 upward to cancel its own weight. The plunger 45 abuts against the lower end of the small-diameter shaft 32a of the governor valve 3 and presses the governor valve 3 upward toward the opening side with a pressing force proportional to the value of the current passing through the coil 43. As the current value increases, the governor valve 3 is displaced more toward the opening side, increasing the gap (opening) between the circumferential surface of the valve hole 14 and the valve body 31, and the gas pressure in the secondary pressure chamber 12 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 fluctuates, the governor valve 3 is displaced via the diaphragm 2, changing its opening to absorb the gas pressure fluctuation and suppressing the gas pressure fluctuation in the secondary pressure chamber 12. Therefore, even if the gas pressure in the primary pressure chamber 11 fluctuates, the gas pressure in the secondary pressure chamber 12 is maintained at a predetermined pressure corresponding to the current value.

[0016] Incidentally, an external impact or the like can cause the governor valve 3 to vibrate in the axial direction (up and down) or in the radial direction (side to side) around the connection point to the diaphragm 2, causing the valve element 31 to collide with the valve seat 13, resulting in governor noise. To suppress governor noise, a cylindrical weight 5 is provided on the second shaft portion 33 of the governor valve 3, with a gap between them, and is freely movable in the axial direction. The governor valve 3 also has an upward-facing annular seat 6 on which the cylindrical weight 5 can seat under its own weight. In this embodiment, the annular seat 6 is provided on the valve element 31 of the governor valve 3.

[0017] A protrusion 61 is provided on the annular seating surface 6, positioned only on a portion of the circumference. The protrusion 61 comes into contact with the lower end surface of the cylindrical weight 5, causing the cylindrical weight 5 to be supported on the annular seating surface 6 in a tilted state rather than upright. As a result, the lower end of the cylindrical weight 5 floats above the annular seating surface 6 between the protrusion 61 and the portion of the circumferentially opposite side of the protrusion 61 that contacts the annular seating surface 6. As a result, the cylindrical weight 5 becomes unstable and easily swings in the radial direction.

[0018] This allows the axial vibration of the governor valve 3 to be damped by the axial vibration in the opposite phase of the cylindrical weight 5, and the radial vibration of the governor valve 3 to be damped by the radial vibration in the opposite phase of the cylindrical weight 5. Therefore, governor noise can be effectively suppressed.

[0019] The protrusions 61 are provided to extend from the inner peripheral edge to the outer peripheral edge of the annular seating surface 6. Therefore, even if the cylindrical weight 5 shifts in the radial direction, the lower end of the cylindrical weight 5 will not come off the protrusions 61, and the effect of damping radial vibration of the governor valve 3 can be reliably obtained. In this embodiment, the protrusions 61 extend in the radial direction from the inner peripheral edge to the outer peripheral edge of the annular seating surface 6, but they may extend in a direction intersecting the radial direction.

[0020] Furthermore, if there is only one protrusion 61, the cylindrical weight 5 becomes too unstable, and the cylindrical weight 5 may swing radially even during normal operation when no governor noise is occurring, which could cause instability in the gas pressure in the secondary pressure chamber 12. Therefore, in this embodiment, as shown in FIG. 2 , two protrusions 61, 61 are provided circumferentially spaced apart from each other on a portion of the circumference of the annular seating surface 6. The central angle θ of the contact points of the two protrusions 61, 61 with the lower end surface of the cylindrical weight 5, i.e., the circumferential width between the apexes of the two protrusions 61, 61, is set to 45°. Here, if the central angle θ of the circumferential width between the apexes of the two protrusions 61, 61 exceeds 60°, the cylindrical weight 5 becomes stable and does not swing radially well when governor noise occurs. On the other hand, if the central angle θ of the circumferential width between the apexes of both convex portions 61, 61 is less than 30°, it is not much different from providing only one convex portion 61, and the cylindrical weight 5 tends to swing radially even under normal conditions when no governor noise is occurring. Therefore, although the cylindrical weight 5 swings radially in a state that causes governor noise, in order to support the cylindrical weight 5 in a moderately unstable state so that the cylindrical weight 5 does not swing radially under normal conditions, the central angle θ of the circumferential width between the apexes of both convex portions 61, 61 should be set to 30° to 60°.

[0021] Next, a second embodiment shown in Figures 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 components and parts as those of the first embodiment are denoted by the same reference numerals. The second embodiment differs from the first embodiment in that the shaft portion around which the cylindrical weight 5 is inserted is changed to a first shaft portion 32, and that a retaining ring 6a is attached to the first shaft portion 32 below the cylindrical weight 5, and the annular seating surface 6 is formed by the upper surface of the portion of the retaining ring 6a that protrudes outward from the outer circumferential surface of the first shaft portion 32.

[0022] Two protrusions 61, 61 are provided circumferentially spaced apart on the upper surface of the retaining ring 6a, which serves as the annular seating surface 6. The contact points of the protrusions 61, 61 with the lower end surface of the cylindrical weight 5, i.e., the central angle θ of the circumferential width between the apexes of the protrusions 61, 61, is set to 45°. Therefore, as in the first embodiment, the cylindrical weight 5 wobbles radially when governor noise occurs, but under normal circumstances, the cylindrical weight 5 can be supported in a moderately unstable state so that it does not wobble radially.

[0023] Each protrusion 61 is formed by pressing the portion of the retaining ring 6a that protrudes outward from the outer circumferential surface of the first shaft portion 32 so that the cross-sectional shape along the circumferential direction is curved upward in an arch shape. Each protrusion 61 extends from the inner circumferential edge to the outer circumferential edge of the annular seating surface 6, which is the upper surface of the portion of the retaining ring 6a that protrudes outward from the outer circumferential surface of the first shaft portion 32. Therefore, as in the first embodiment, even if the cylindrical weight 5 shifts in the radial direction, the lower end of the cylindrical weight 5 will not come off the protrusion 61. The retaining ring 6a has a notch 6b formed in one location in the circumferential direction.

[0024] Although the 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, two protrusions 61 are provided on a portion of the annular seating surface 6 in the circumferential direction, but it is also possible to provide three or more protrusions. In this case, the central angle of the circumferential width between the contact portions of two of these protrusions located on both sides in the circumferential direction with respect to the lower end surface of the cylindrical weight 5 should be set to 30° to 60°. In the above embodiment, the two protrusions 61, 61 are two protrusions located on both sides in the circumferential direction.

[0025] Alternatively, a convex portion may be provided on a portion of the circumferential direction of the lower end surface of the cylindrical weight 5, and the convex portion may come into contact with the annular seating surface 6, so that the cylindrical weight 5 is supported on the annular seating surface 6 in a tilted state rather than upright. Furthermore, in the above embodiment, the secondary pressure chamber 12 is provided above the primary pressure chamber 11, but the secondary pressure chamber 12 may be provided below the primary pressure chamber 11. In this case, the casing 1 and the governor valve 3 are arranged upside down from those shown in FIGS. 1 and 3 . Therefore, the cylindrical weight 5 may be fitted onto the first shaft portion 32 extending upward from the valve disc portion 31 of the governor valve 3 with a gap therebetween, and the annular seating surface 6 may be formed on the upper surface of the valve disc portion 31. Alternatively, the cylindrical weight 5 may be fitted onto the second shaft portion 33 extending downward from the valve disc portion 31 with a gap therebetween, and the annular seating surface 6 may be formed on the upper surface of a retaining ring 6a attached to the second shaft portion 33. Furthermore, in the above embodiment, the present invention is applied to a gas governor that constitutes a proportional valve device with a governor that includes an electromagnetic solenoid 4, but the present invention can also be applied to a normal gas governor that does not include an electromagnetic solenoid 4. [Explanation of symbols]

[0026] 1...casing, 11...primary pressure chamber, 12...secondary pressure chamber, 13...valve seat, 14...valve hole, 2...diaphragm, 3...governor valve, 31...valve body portion, 32...first shaft portion, 33...second shaft portion, 5...cylindrical weight, 6...annular seat surface, 61...convex portion.

Claims

1. a casing having a primary pressure chamber, a secondary pressure chamber above or below the primary pressure chamber, and a valve seat between the primary pressure chamber and the secondary pressure chamber; a diaphragm facing the primary pressure chamber on the side opposite the valve seat; and a governor valve having a valve body portion inserted into a valve hole formed in the valve seat and having an outer diameter gradually increasing toward an end portion on the secondary pressure chamber side, wherein a first shaft portion of the governor valve extending from the valve body portion 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, thereby suppressing gas pressure fluctuations in the secondary pressure chamber, A governor valve is provided with a cylindrical weight that is inserted axially and freely movable with a gap between it and a second shaft portion or a first shaft portion of the governor valve that extends from the valve body portion to the opposite side of the diaphragm, and the governor valve is provided with an annular seating surface on which the cylindrical weight can be seated by its own weight, A gas governor characterized in that a convex portion is provided on one of the annular seating surface and the lower end surface of the cylindrical weight, positioned only at a portion in the circumferential direction, and the convex portion contacts the other of the annular seating surface and the lower end surface of the cylindrical weight, thereby supporting the cylindrical weight on the annular seating surface in a state tilted from an upright position.

2. 2. The gas governor according to claim 1, wherein a plurality of the convex portions are provided at intervals in the circumferential direction on the portion in the circumferential direction of one of the annular seating surface and the lower end face of the cylindrical weight, and a central angle of a circumferential width between contact portions of two of the convex portions located on both circumferential sides of the other of the annular seating surface and the lower end face of the cylindrical weight is set to 30° to 60°.

3. 3. The gas governor according to claim 1, wherein the convex portion is provided on the annular seating surface, and the convex portion is provided so as to extend from an inner peripheral edge to an outer peripheral edge of the annular seating surface.

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