JP2005114117A - Constant flow motor operated valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant flow motor operated valve which is capable of easily conducting installation working and maintenance and can reduce manufacturing cost in low noise. <P>SOLUTION: The constant flow motor operated valve is constructed of an electrically operated control valve 11 and a constant flow-rate apparatus 12 removably incorporated into a valve body 13 of the electrically operated valve 11. The constant flow-rate apparatus 12 is constituted of a tubular holder 30, a ring-like orifice plate 31 comprising an elastic body which is fitted and inserted into the holder 30 and a retaining ring 32 comprising C-ring which prevents the orifice plate 31 from falling from the holder 30. It also removably fixes in the valve body 13 of the electrically operated control valve 11 by means of piping connecting means 21. The piping connecting means 21 is constituted of a union joint 45 and a union nut 46. The constant flow motor operated valve presses projection body 36 of the holder 30 by the union joint 45 and comes into press contact with a taper hole 22 of a valve body 13 by means of connecting the union joint 45 with the valve body 13 by the union nut 46. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a constant flow motor-operated valve that controls a flow rate to be substantially constant.

In general, the flow control of a fan coil unit (air conditioner that combines a heat exchange coil and a fan) in a building air conditioning system is to achieve the highest cooling and heating efficiency by flowing a specified flow rate, and to perform optimal room temperature control. Can do. For this reason, a normal electric on / off valve and a constant flow valve (constant flow device) are used, and the flow rate of water supplied to the fan coil unit is kept substantially constant by this constant flow valve regardless of the pressure fluctuation on the primary side. Various types of such constant flow valves have been conventionally proposed (see, for example, Patent Documents 1 to 3). The applicant has not been able to find prior art documents closely related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
Japanese Utility Model Publication No. 2-9906 Japanese Patent Laid-Open No. 11-270743 JP 2002-351549 A

  The constant flow device disclosed in the Japanese Utility Model Laid-Open No. 2-9906 is configured such that an outer cylinder and a round bar-shaped shaft provided at the axial center of the outer cylinder radiate from the shaft at the inlet side end of the outer cylinder. A cartridge integrally formed by connecting with a plurality of formed ribs, a needle slidably crowned on the shaft, and a nozzle protruding from the opening on the outlet side of the outer cylinder facing the needle And a coil spring that urges the needle in a direction away from the nozzle (inflow side).

  The low noise type constant flow rate device described in JP-A-11-270743 is provided with a nozzle case at the downstream side opening of a cylindrical outer frame having a flow path in the axial direction. A cylindrical wire mesh screen is incorporated into the nozzle, and a nozzle made of rubber plastic is provided at the peripheral edge of at least the inlet side of the fluid passage hole. The needle incorporated in the cylindrical outer frame is elastically supported by a coil spring. It is what you do.

  The constant flow device described in Japanese Patent Application Laid-Open No. 2002-351549 elastically supports a needle disposed opposite to an orifice in a cylindrical body by a coil spring, and moves the position of the needle according to the pressure of the fluid. The flow is operated, the tip of the needle is formed into a cylindrical shape with a flat surface, a cylinder hole is opened at the input end, the shaft ring is fitted into the input end of the cylinder, and the cylinder hole is installed. A cylindrical sealing material formed of an elastic material such as rubber is put on the outer flange portion of the cylindrical body to form a convex bulging portion that circulates on the side periphery of the cylindrical sealing material. It is intended to give it.

  In building instrumentation, air conditioning equipment includes a pump, a refrigerator (heat source), a fan coil unit, a control panel, and the like, and there are two types of piping methods, a direct return method and a reverse return method. As shown in FIG. 7, in the direct return method, the secondary side pipe 2 of the fan coil unit 1 provided for each floor is directly connected to the main secondary side pipe 3, so that the lower the floor of the building, the lower the pressure. In addition, since the differential pressure is different for each floor, it is necessary to adjust the flow rate of the fluid 4 supplied to the fan coil unit 1 of each floor at each floor. It is also necessary to adjust each time the load changes.

  On the other hand, in the reverse return method, as shown in FIG. 8, the secondary side pipe 2 of the fan coil unit 1 for each floor is connected to the sub secondary side pipe 3 ′, and the upper end of the sub secondary side pipe 3 ′ is connected. Since it is connected to the main secondary pipe 3 on the higher floors, the differential pressure on each floor can be made approximately constant. However, if the number and capacity of the fan coil units 1 on each floor are different, match the capacity. It is necessary to adjust the flow rate.

  Therefore, if the constant flow valve 6 is provided in the primary side pipe 7 of each floor in addition to the electric on / off valve (electric control valve) 5, it is possible to keep the flow rate constant without the need for adjustment work. In addition, since the electric on / off valve 5 is provided, energy saving can be achieved by closing the electric on / off valve 5 and stopping the water supply in the floor not in use. 7 and 8, 8 is a pump, and 9 is a refrigerator.

  By the way, in the construction of building air conditioning equipment, since the contractors are usually different between the automatic control area and the equipment area, the electric on / off valve 5 which is the operation end for controlling the flow rate is installed on site by the contractor in the automatic control area. On the other hand, the constant flow valve 6 is installed on site by a contractor in the equipment area. As a result, the electric on / off valve 5 and the constant flow valve 6 were separately installed.

As described above, in the conventional air conditioning equipment, the electric on / off valve 5 and the constant flow valve 6 must be installed separately for one fan coil unit 1, which requires a problem of installation work and maintenance. there were.
In addition, since the electric on / off valve 5 and the constant flow valve 6 are installed separately, and how far the two valves are installed is determined after installation, the electric on / off valve 5 and the constant flow valve 6 are installed at the time of shipment from the factory. The overall effect on air conditioning control when installed on site cannot be predicted at all. Further, the confirmation work must be performed after installation on the site, and there are also problems that the confirmation work is troublesome and the flow rate is insufficient or excessive without being as designed.

  The conventional constant flow valves disclosed in Patent Documents 1 to 3 are all sensitive to pressure fluctuations because they employ a system in which the needle is urged by a coil spring and balanced with the fluid pressure. When applied to a building air conditioner, there is a problem that noise is likely to occur due to vibrations caused by pressure fluctuations induced by other valves.

  The present invention has been made to solve the above-described conventional problems, and the object of the present invention is to facilitate installation work and maintenance, and to reduce manufacturing costs with low noise. It is to provide a constant flow motor-operated valve.

  In order to achieve the above object, a first invention includes an electric control valve and a constant flow device incorporated in a valve body of the electric control valve. The constant flow device is provided with a cylindrical holder and the holder. It is composed of a ring-shaped orifice plate made of an elastic body fitted in and a retaining ring for preventing the orifice plate from dropping from the holder, and is fixed in the valve body so that it can be taken out by a pipe connecting means. It is a thing.

  According to a second aspect of the present invention, in the first aspect of the present invention, a tapered hole having a diameter increasing outward is formed in an opening on one end side of the valve body of the electric control valve, and an inclination substantially equal to the tapered hole is formed on an outer periphery of the holder. An annular projecting body having an angle tapered surface is integrally projected, the pipe connecting means is constituted by a union joint and a union nut, and the valve body and the union joint are connected by the union nut, The protruding body is pressed by the union joint, and the tapered surface is coupled to the tapered hole.

  According to a third invention, in the first or second invention, the retaining ring is configured by a C ring, and an annular groove into which the C ring is fitted is formed on an inner peripheral surface of the holder.

In the first aspect of the invention, since the electric control valve and the constant flow device are integrated, the distance between the electric control valve and the constant flow device is determined at the design and manufacturing stage. It is possible to grasp the overall influence on the air conditioning control of the electric control valve and constant flow device when installed. Therefore, the confirmation work after the installation at the site is unnecessary, the flow rate as designed can be realized, and the flow rate deficiency or flow rate excess can be prevented.
In the constant flow device, the orifice plate is elastically deformed by a change in the pressure of the fluid, and the hole diameter of the orifice changes thereby controlling the flow rate of the fluid flowing to the secondary side to be constant. No coil spring is required, and the structure can be simplified and the generation of noise can be prevented.
In the second invention, when the union nut is loosened and the union joint is removed from the valve body, the constant flow rate device can be easily removed from the valve body. The tapered surface of the holder is brought into pressure contact with the tapered hole of the valve body, so that the constant flow rate device is automatically aligned with the valve body.
In the third invention, the C-ring prevents the orifice plate from falling off the holder, and when the C-ring is removed from the holder, the orifice plate can be taken out and replaced.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
1 is a cross-sectional view showing an embodiment of a constant flow motor-operated valve according to the present invention, FIG. 2 is a cross-sectional view of a constant flow device, and FIG. 3 is a diagram showing a state when an orifice plate is unloaded and a differential pressure is applied. It is an expanded sectional view of a part.
In FIG. 1, a constant flow motor-operated valve generally indicated by reference numeral 10 is used in a building air-conditioning system, and includes an electric control valve 11 and a constant flow meter 12.

  The electric control valve 11 is an on / off valve made up of a well-known electric ball valve. The valve body 13 is made up of a straight pipe, and can be rotated through a pair of seat rings 14 and 14 at the center of the valve body 13. A ball-shaped valve body 15 incorporated into the valve body 13, a stem 16 having a cylindrical portion 13A projecting integrally upward at the center of the upper surface of the valve body 13 and having the valve body 15 attached to the inner end thereof; The operation unit 17 is installed on the cylindrical portion 13A and reciprocally rotates the stem 16 within an angle range of 90 °. A primary pipe 19 is connected to the upstream opening 18 of the valve body 13, and the constant flow device 12 is incorporated in the downstream opening 20 so as to be removable by a pipe connecting means 21. The downstream opening 20 is formed with a tapered hole 22 whose diameter increases toward the outside, and a secondary pipe 23 is connected via the pipe connecting means 21. In the center of the ball 15, a straight flow hole 24 perpendicular to the axis of the stem 16 is formed.

  2 and 3, the constant flow device 12 includes a cylindrical holder 30, a ring-shaped orifice plate 31 fitted in the holder 30, and a retaining ring 32 for preventing the orifice plate 31 from coming off. It consists of and. Therefore, this constant flow device 12 has a feature that a needle and a coil spring are not required in terms of structure.

  The holder 30 is made of metal (for example, a bronze casting), the downstream opening end portion forms a small-diameter hole portion 33, and the upstream side from the small-diameter hole portion 33 forms a large-diameter hole portion 34. The orifice plate 31 is fitted into the hole 34. The small-diameter hole portion 33 is formed in a hole that expands in a curved manner toward the inside. The step portion 35 provided between the small diameter hole portion 33 and the large diameter hole portion 34 forms a support portion that supports the outer peripheral portion of the orifice plate 31. Further, an annular ridge 36 is integrally projected over the entire circumference near the downstream end on the outer peripheral surface of the holder 30. The projecting body 36 has a trapezoidal cross-sectional shape, whereby a tapered surface 36a positioned on the upstream side inclined with respect to the axis of the holder 30, a vertical surface 36b positioned on the downstream side, and the tapered surface. It is comprised by the horizontal surface 36c which connects the surface 36a and the vertical surface 36b. The taper surface 36a is inclined toward the downstream side, and the inclination angle is set equal to the inclination angle of the taper hole 22 of the valve body 13.

  The orifice plate 31 is formed in a ring shape whose outer diameter is smaller than the hole diameter of the large diameter hole 34 of the holder 30 by an elastic material such as rubber (for example, NBR), and the hole of the small diameter hole 33 is formed in the center. A circular orifice (diaphragm) 40 having a smaller diameter is provided, and the outer peripheral portion is supported by the step portion 35.

The retaining ring 32 is made of a C-ring formed of stainless steel or the like, and is detachably fitted in an annular groove 41 formed on the inner peripheral surface of the large-diameter hole portion 34 of the holder 30. A sufficient gap G is set between the retaining ring 32 and the orifice plate 31. The gap G and the gap G ₁ between the large-diameter hole 34 and the orifice plate 31 are provided in order to allow free elastic deformation of the orifice plate 31 due to the differential pressure.

  In FIG. 1, the pipe connecting means 21 is composed of two members, a cylindrical union joint 45 and a union nut 46. In the union joint 45, an annular protrusion 47 is integrally projected at an upstream end portion of the outer peripheral surface, and a taper screw 48 into which the downstream pipe 23 is screwed is formed at a downstream end portion. The union nut 46 connects the valve body 13 and the union joint 45, and is fitted to the outer periphery of the union joint 45 so that the union nut 46 is engaged with the projecting body 47 from the downstream side to the inner peripheral surface. A female screw 50 is formed. The female screw 50 presses the union joint 45 against the downstream opening end surface of the valve main body 13 by screwing with a male screw 51 formed on the downstream outer peripheral surface of the valve main body 13. In addition, the union joint 45 presses the protrusion 36 of the holder 30 and presses the tapered surface 36 a against the tapered hole 22 of the valve body 13.

In the constant flow motor-operated valve 10 having such a structure, the orifice plate 31 of the constant flow meter 12 is elastically deformed by the fluid pressure, so that the flow rate of the fluid 4 flowing through the constant flow motor-operated valve 10 to the downstream pipe 23. Is controlled to be substantially constant. That is, when the electric control valve 11 is opened and the fluid 4 flows through the constant flow device 12, a pressure difference is generated between the upstream pressure P ₁ and the downstream pressure P ₂ (P ₁ > P ₂ ) of the constant flow device 12. For this reason, the orifice plate 31 is elastically deformed downstream from the unloaded natural state shown by the solid line in FIG. 3 to the downstream side as shown by the two-dot chain line in accordance with the differential pressure (P ₁ -P ₂ ). The hole diameter of 40 is reduced, and the flow area is reduced, so that the flow rate of the fluid 4 flowing through the constant flow device 12 is controlled to be constant.

In the constant flow rate operation of the constant flow device 12, the retaining ring 32 is provided with a sufficient gap G on the upstream side of the orifice plate 40, and between the inner peripheral surface of the large-diameter hole 34 and the outer periphery of the orifice plate 31. Since the appropriate gap G ₁ is provided, even if the orifice plate 31 is elastically deformed toward the small-diameter hole 33 side and the outer peripheral portion is inclined toward the retaining ring 32 side, as shown by the two-dot chain line, the orifice plate 31 31 does not contact the inner peripheral surface of the retaining ring 32 or the large-diameter hole 34. Therefore, the orifice plate 31 does not restrain free elastic deformation and exhibits a constant flow rate function.

FIG. 4 is a diagram showing the flow characteristics of the constant flow motor-operated valve.
In the figure, the horizontal axis indicates the differential pressure (MPa) between the upstream pressure P ₁ and the downstream pressure P ₂ , and the vertical axis indicates the flow rate (L / min) flowing through the constant flow rate device 12. Curve 1 is a flow characteristic of a small constant flow meter 12 that flows 6 L (liters) per minute, Curve 2 is a flow characteristic of a medium constant flow device 12 that flows 12 L (liters) per minute, and Curve 3 is 24 L (minutes). Liter) is a flow characteristic of the large constant flow device 12 that flows. As is apparent from this figure, the flow rate can be controlled to be substantially constant in any of the constant flow devices 12.

  Further, since the constant flow device 12 is not provided with a needle or a coil spring, the constant flow device 12 is less likely to vibrate or generate noise due to pressure fluctuations, and enables a low noise type constant flow motor-operated valve 10. Incidentally, when the noise during operation of the constant flow motor-operated valve 10 was measured (measured at a position 1 m behind the valve and 1 m horizontal from the pipe), the differential pressure ΔP was 0.2 MPa or less and NC 35 or less. The noise measurement environment conforms to IEC standards.

Moreover, since the constant flow motor-operated valve 10 according to the present invention is configured by integrally incorporating the constant flow device 12 into the electric control valve 11, installation at the site is performed at once by a contractor in the automatic control area or the equipment area. Installation and maintenance are easy.
In particular, since the distance between the electric control valve 11 and the constant flow device 12 is determined at the design stage, it is possible to grasp in advance the overall influence on the air conditioning control when the constant flow electric valve 10 is installed on site. Yes, there is no need for confirmation after installation on site. Moreover, since the flow rate control as designed can be performed, the flow rate does not become insufficient or excessive.
Further, since the tapered surface 36 a of the protrusion 36 is pressed against the tapered hole 22, the constant flow device 12 can be automatically aligned with the valve body 13.
Furthermore, when the retaining ring 32 is removed from the holder 30, the orifice plate 31 can be removed from the holder 30 and easily replaced with a new one.
In addition, when the electric control valve 11 and the constant flow device 12 are integrated, parts for attaching the constant flow device 12 to the pipe can be omitted. Can be provided easily and inexpensively.

FIG. 5 is a cross-sectional view showing another embodiment of the constant flow device, and FIG. 6 is an enlarged cross-sectional view of a main part showing a state when the orifice plate is not loaded and when a differential pressure is applied.
In this embodiment, the small-diameter hole portion 33 of the holder 30 is formed into a straight hole, a conical recess 61 communicating with the orifice 40 is formed at the center of the downstream surface 60 of the orifice plate 31, and the outer peripheral portion is formed. It is formed on a flat surface. Therefore, the orifice plate 31 is supported by the step portion 35 of the holder 30 at the outer peripheral portion formed of a flat surface surrounding the recess 61. Other structures are the same as those of the constant flow device 12 in the above-described embodiment.

  In the constant flow device 63 having such a structure, it is obvious that the flow rate on the secondary side can be controlled to be substantially constant similarly to the constant flow device 12.

In the embodiment described above, an electric on / off valve composed of a two-way ball valve is used as the electric control valve 11. However, the present invention is not limited to this, and other on / off valves such as a butterfly valve or a valve having flow characteristics are used. Also good.
In addition, the pipe connecting means 21 is not limited to the union joint 45 and the union nut 46, and pipe connecting means having another appropriate structure can be used.
Furthermore, the constant flow device 12 is not limited to the downstream opening of the valve main body 13 of the electric control valve 11 and may be incorporated in the upstream opening.

It is sectional drawing which shows one Embodiment of the constant flow motor-operated valve which concerns on this invention. It is sectional drawing of a constant flow device. It is an expanded sectional view of the principal part which shows the state at the time of no load of a orifice plate, and the time of differential pressure application. It is a figure which shows the flow volume characteristic of a constant flow motor-operated valve. It is sectional drawing which shows other embodiment of a constant flow device. It is an expanded sectional view of the principal part which shows the state at the time of no load of a orifice plate, and the time of differential pressure application. It is a figure which shows the direct return system of the piping system of an air conditioner. It is a figure which shows the reverse return system of the piping system of an air conditioner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Constant flow motor valve, 11 ... Electric control valve, 12 ... Constant flow device, 13 ... Valve body, 21 ... Pipe connection means, 22 ... Taper hole, 30 ... Holder, 31 ... Orifice plate, 32 ... Retaining ring, 36 ... projection member, 36a ... tapered surface 40 ... orifice, 41 ... annular groove, 45 ... union, 46 ... union nut, G, G ₁ ... gap.

Claims (3)

An electric control valve and a constant flow device incorporated in the valve body of the electric control valve;
The constant flow device includes a cylindrical holder, a ring-shaped orifice plate made of an elastic body inserted into the holder, and a retaining ring for preventing the orifice plate from dropping from the holder. A constant flow motor-operated valve fixed inside the valve body so as to be removable by a pipe connecting means. The constant flow motor-operated valve according to claim 1,
An annular protrusion having a tapered surface having an inclined angle substantially equal to that of the tapered hole formed on the outer periphery of the holder is formed in an opening on one end side of the valve body of the electric control valve. Projecting together,
The pipe connecting means is composed of a union joint and a union nut,
A constant flow motor-operated valve, wherein the valve body and the union joint are connected by the union nut, the ridge body is pressed by the union joint, and the tapered surface is coupled to the tapered hole. The constant flow motor-operated valve according to claim 1 or 2,
A constant flow motor-operated valve characterized in that the retaining ring is constituted by a C-ring, and an annular groove is formed on the inner peripheral surface of the holder to fit the C-ring.

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