JP5693512B2 - Proportional valve - Google Patents

Description

  The present invention relates to a proportional valve provided with a rubber diaphragm.

  A conventional proportional valve of this type is provided with a diaphragm so as to isolate the primary chamber upstream of the valve port from the outside. This diaphragm is provided so that the flow rate of the gas passing through the valve port does not fluctuate even if the pressure in the primary chamber, that is, the primary pressure fluctuates. An opening is provided at the center of the diaphragm, and a boss formed on the end face of the valve shaft is penetrated from the primary chamber side into the opening. A collar and a fastener are attached to the boss portion from the outside in a state where the boss portion passes through the opening, and the valve shaft and the diaphragm are connected to each other.

  When the primary pressure fluctuates, the diaphragm is displaced in conjunction with the fluctuation, so that the valve shaft connected to the center of the diaphragm is also displaced.

  The other end of the valve shaft passes through the valve port and is positioned in the secondary chamber, and a valve element positioned in the secondary chamber is formed on the valve shaft. When the valve shaft is displaced, the valve body is also displaced, thereby increasing or decreasing the opening area of the valve port. That is, when the primary pressure rises and the valve shaft is displaced to the outside, the valve body approaches the valve opening and narrows the opening area. Conversely, when the primary pressure decreases, the valve shaft is displaced to the secondary chamber side, and the valve body is moved away from the opening to increase the opening area (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2007-162911 (FIG. 1)

  In such a proportional valve, when the diaphragm is attached to the boss formed on the end face of the valve shaft, the boss is inserted into the opening formed at the center of the diaphragm. The diaphragm is filled with gas. Since the chamber is isolated from the outside, the gas must be prevented from leaking from the opening. Therefore, the diameter of the opening is set to be narrower than the diameter of the boss part, and when the boss part is inserted into the opening, the opening is expanded by the boss part, so that the inner peripheral surface of the opening closely contacts the outer peripheral surface of the boss part. Has been.

  If a collar is attached to the boss in the penetrating state and then a fastener is attached, the periphery of the opening is compressed in the thrust direction, which is the axial direction, and the air tightness is further secured by closely contacting the end face of the valve shaft. It is comprised so that.

  As described above, since the diameter of the diaphragm opening is set to be narrower than the diameter of the boss portion, when the boss portion is inserted into the opening, the inner peripheral surface of the opening is in close contact with the entire length of the outer peripheral surface of the boss portion. It will be dragged in the state. Due to this dragging, the periphery of the diaphragm opening is deformed, and the collar and the fastener may be attached in the deformed state. As described above, if the peripheral edge portion of the opening is attached in a deformed state, the airtightness cannot be secured, and the deformation characteristic with respect to the primary pressure of the diaphragm does not follow the designed characteristic, and the flow rate cannot be kept constant.

  Therefore, in view of the above problems, an object of the present invention is to provide a proportional valve in which the opening peripheral portion of the diaphragm is not deformed when the diaphragm and the valve shaft are connected to each other.

In order to solve the above problems, a proportional valve according to the present invention includes a rubber diaphragm provided so as to isolate the primary chamber on the upstream side of a valve port through which a gas passes from the outside, and the center of the diaphragm. A boss formed on the end face of the valve shaft is inserted through the provided opening from the primary chamber side and penetrated, and the fastener is attached to the tip of the boss with the collar attached to the boss protruding outside. In the proportional valve in which the diaphragm and the valve shaft are connected to each other by being engaged with the formed engaging portion, the portion sandwiched between the engaging portion of the boss portion and the end surface of the valve shaft is It is formed in two steps, a large diameter part on the end face side of the valve shaft and a small diameter part on the tip side, and the diameter of the small diameter part is set smaller than the diameter of the opening when no boss part is inserted into the opening of the diaphragm, The height dimension from the end face of the valve shaft of the large diameter part The fit tool set to be longer than the sum the dimensions of the thicknesses of the color of the periphery of the opening of the diaphragm in a state before mounting the boss portion, and the inner diameter of the fastener in the same as the diameter of the small diameter portion The fastener is attached to the small diameter portion .

  According to the above configuration, since the boss portion is formed in two steps and the diameter of the small diameter portion on the tip side is made thinner than the diameter of the opening of the diaphragm, when the opening passes through the small diameter portion, the outer peripheral surface of the small diameter portion and the opening Friction does not occur between the inner peripheral surface and the peripheral edge of the opening is not deformed. In addition, if the height dimension of a large diameter part has the total dimension of the thickness of the opening periphery in the state which attached the fastener, and the thickness of a color | collar, it can fully ensure airtightness. However, since the periphery of the opening is compressed when the fastener is attached, the collar should be positioned at the small diameter portion before attaching the fastener if the height of the large diameter portion is minimized as described above. Therefore, when the collar is moved from the small diameter portion to the large diameter portion when the fastener is attached, the collar may scrape the surface of the boss portion. Therefore, in the above configuration, the collar is positioned at the large diameter portion before the fastener is attached so that the collar does not cut the boss portion.

  As is apparent from the above description, the present invention provides a diaphragm and valve without deforming the peripheral edge portion of the opening because friction does not occur between the small diameter portion and the opening when the diaphragm opening passes through the small diameter portion. The shaft can be connected to each other.

The perspective view which shows the external appearance of the proportional valve by this invention II-II sectional view showing the internal structure of the proportional valve An exploded perspective view showing a connection structure between the diaphragm and the valve shaft Expanded sectional view of the IV part showing the shape of the boss part

  Referring to FIGS. 1 and 2, reference numeral 1 denotes a proportional valve according to the present invention, which is incorporated, for example, in a gas hot water supply device and controls the flow rate of gas supplied to a gas burner outside the figure. Further, the proportional valve 1 has a governor function for keeping the flow rate to the gas burner constant even when the primary pressure fluctuates, in addition to increasing or decreasing the gas flow rate.

  A valve port 21, which is a gas passage, is formed in the body member 2 of the proportional valve 1. And the valve body 31 which adjusts the opening area of this valve port 21 is provided in the secondary chamber side. The valve body 31 is formed integrally with the valve shaft 3, and a boss portion 32 is formed at the lower end of the valve shaft 3 in FIG. The boss portion 32 is attached to the diaphragm 4.

  The diaphragm 4 isolates the primary chamber from the outside, and is composed of a rubber thin film. A connection structure between the diaphragm 4 and the valve shaft 3 will be described with reference to FIGS. 3 and 4. 3 and 4 are shown upside down with respect to the posture shown in FIG. 2 for easy understanding.

  The diaphragm 4 is an integrally molded product of rubber, and has an opening 41 at the center. The boss portion 32 is inserted into the opening 41 from the primary chamber side and penetrated. Then, the tip of the boss part 32 penetrates the diaphragm 4 and protrudes to the outside. The collar 5 was attached to the protruding boss portion 32, and finally the fastener 6 was fitted to connect the diaphragm 4 and the valve shaft 3 to each other.

  More specifically with reference to FIG. 4, the boss portion 32 is formed in two steps of a small diameter portion 32 a at the tip and a large diameter portion 32 b on the end surface 30 side of the valve shaft 3. The diameter D1 of the small diameter portion 32a is set smaller than the diameter of the opening 41. Therefore, when the opening 41 passes through the small-diameter portion 32a, the inner peripheral surface of the opening 41 does not come into strong contact with the outer peripheral surface of the small-diameter portion 32a, and therefore little frictional force is generated between them. Therefore, the periphery of the opening 41 can reach the large diameter portion 32b without being deformed.

  When the collar 5 is attached in this state, the periphery of the opening 41 is not compressed yet, so that the height of the collar is finally higher than the height when the fastener 6 is attached. Here, if the thickness of the periphery of the opening 41 in the uncompressed state is A and the thickness of the collar is B, the height dimension from the end face 30 of the large diameter portion 32b is C, and the height dimension C is A and B. (C> A + B). Then, as shown in FIG. 4, since the collar 5 is already positioned at the large diameter portion 32b before the fastener 6 is attached, the fastener 6 is attached and the periphery of the opening 41 is compressed in that state. Even if the position of the collar 5 sinks to the end face 30 side, there is no possibility that the collar 5 scrapes the surface of the boss portion 32. In addition, in this structure, since the fastener 6 is attached to the small diameter part 32a, the fastener 6 can be made smaller than the conventional one, and as a result, the size reduction of the proportional valve 1 can be helped.

  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.

DESCRIPTION OF SYMBOLS 1 Proportional valve 2 Body member 3 Valve shaft 4 Diaphragm 5 Collar 6 Fastening 21 Valve port 30 End surface 31 Valve body 32 Boss part 32a Small diameter part 32b Large diameter part 41 Opening

Claims (1)

A rubber diaphragm provided to isolate the primary chamber upstream of the valve port through which the gas passes from the outside, and a boss formed on the end face of the valve shaft at an opening provided at the center of the diaphragm The boss part is inserted into the boss part by inserting it from the primary chamber side and engaging it with the engaging part formed at the tip part of the boss part with the collar attached to the boss part protruding outward. In a proportional valve that is attached and the diaphragm and valve shaft are connected to each other, the portion sandwiched between the engaging portion of the boss portion and the end surface of the valve shaft is the large diameter portion on the end surface side of the valve shaft and the small diameter on the tip side. The diameter of the small diameter part is set smaller than the diameter of the opening when the boss part is not inserted into the opening of the diaphragm, and the height dimension from the end face of the valve shaft of the large diameter part is set. In the state before attaching the fastener to the boss, Set of to be longer than the sum the dimensions of the thickness and the color of the thickness of the opening edge, and that the inner diameter of the fastener and to attach to the small diameter portion of the fastener in the same as the diameter of the small diameter portion Characteristic proportional valve.

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