Description

CONTROL VALVE INTEGRATED CONSTANT FLOW TYPE

AND ON/OFF TYPE, PROPORTIONAL TYPE CONTROL

VALVE AND MUTUAL CONVERTING METHOD

Technical Field

[1] The present invention relates to a control valve, more particularly a control valve that is provided in a boiler system and controls supply of heating water to each room that needs heating. Background Art

[2] In general, a hot water distributor that distributes heating water to each room that needs heating is generally provided in a boiler system. The hot water distributor supplies heating water, which is heated by a heat exchanger of a boiler and supplied through heating water supply pipe, to each room. The supplied heating water transfers heat energy to each room and is cooled, and then flows to a heating water return pipe. The hot water distributor is provided with a control valve that controls the flow rate of heating water that is supplied to each room.

[3] The control valve is divided into three types, an on/off type control valve, a constant flow control valve, and a proportional type control valve.

[4] The on/off type control valve stops supplying heating water by shutting a closing member when temperature reaches temperature set by a user, and supplies heating water by opening the closing member when the temperature drops under the set temperature.

[5] The constant flow control valve is a device for preventing heating water from flowing at a flow rate set in the valve itself. When there is a plurality of rooms in a building and heating water is applied to the rooms from one boiler, the time taking the temperature of each room to reach a predetermined temperature is different because the pipe lengths of the rooms are different. Accordingly, the times taken to reach a predetermined temperature of each room become uniform by providing the constant flow control valve in the heating water pipe supplied to each room to remove the non- uniformity of heating.

[6] On the other hand, reducing the flow rate supplied to each other by using the constant flow control valve increases temperature of boiler-supply water, in which the boiler stops the operation to prevent overheating when the temperature of the boiler-supply water excessively increases. Accordingly, the boiler may early stop the operation, in which desired heating cannot be achieved. In order to overcome the problem, a differential pressure valve that bypasses heating water to a return pipe when pressure of a

heating water supply pipe increases over a predetermined pressure was disposed between the supply pipe and the return pipe.

[7] However, there was a problem in that the heating water in the supply pipe is directly bypassed to the return pipe by the differential pressure valve, such that the heating water is not sufficiently supplied to each room and desired heating cannot be achieved.

[8] Further, in the constant flow control valve, a user cannot change the flow rate at his/ her option once the flow rate is set according to pipe length of each room, such that heating becomes non-uniform again when the length of the heating pipe is changed by remodeling or expanding a veranda.

[9] The proportional type control valve has been developed to overcome the above problem. The proportional type control valve is a valve that controls the flow rate of heating water to maintain pleasant interior environment.

[10] However, the proportional type control valve in the related art controls the flow rate of supplied heating water by controlling the amount of opening of a closing member in response to flow rate data fed-back from a flow sensor, in which when the flow sensor is contaminated and outputs wrong information due to a lot of contaminants existing in the heating water, the boiler may make misoperation.

[11] Further, when the flow sensor is not used, a method of controlling the amount of opening of the closing member by rotating a stepping motor on the basis of the temperature of the heating water, which is fed-back from the temperature sensor, has been proposed, in which, however, since the stepping motor uses DC power, specific components, such as a transformer and a rectifier, are required to convert commercial alternating power into direct power and cost increases.

[12] On the other hand, since using the proportional type control valve increases the cost, the on/off type control valve and the constant flow control valve are applied together. However, the on/off type control valve and the constant flow control valve are also separately installed in this configuration, such that the structure is complicated and the cost increases.

Disclosure of Invention Technical Problem

[13] In order to overcome the above problems, it is an object of the present invention to provide a control valve integrated constant flow type and on/off type that simplifies the structure of a hot water distribution system by integrally forming an on/off type control valve with a constant flow control valve.

[14] Further, it is another object of the invention to provide a control valve that can be used as a control valve integrated constant flow type and on/off type, or a proportional type control valve, if needed, by providing components for implementing an on/off

type control valve, a constant flow control valve, and a proportional control valve, for one valve.

[15] It is another object of the invention to provide a proportional type control valve that can proportionally control flow rate of heating water that is supplied to each room by using an inexpensive alternating current motor, in addition to not using a flow sensor. Technical Solution

[16] In order to achieve the object of the present invention, a control valve of claim 1 includes: a motor; a closing member that is reciprocated by rotation of the motor to adjust the opening/closing amount of heating water flow channel; a rotary plate that integrally rotates with the motor and has a first projection and a second projection at different distances from the center on one side; a first printed circuit board that turns on/off the motor at the top dead center and the bottom dead center of the closing member by the first projection and the second projection of the rotary plate; a shaft that has a lower end where the closing member is connected; an upper guide member that guides the shaft to reciprocate up/down therein; and a constant flow operating member that is engaged with the outer circumference of the side of the upper guide member and partially exposed outside the a case, in which as the exposed portion of the constant flow operating member is rotated, the constant flow is controlled while the upper guide member rotates and the closing member reciprocates up/down, and as the motor is rotated, the closing member is on/off.

[17] A control valve of claim 2 may be configured such that the closing member reciprocates up/down along the outer circumference of the cam- shaped cam member that is rotated by the motor.

[18] A control valve of claim 3 may be configured such that a portion of the upper end of the rotary plate is exposed outside the case and integrally and coaxially formed with the cam member.

[19] A control valve of claim 4 may be configured such that a plurality of insertion holes is formed on the lower surface of the upper guide member; and a lower guide member that is fixed under the upper guide member and has a thread on the inner circumference, a locking rotary member of which a portion of the upper portion is inserted and locked in the insertion hole, which has a thread on the outer circumference and changes in up-down position inside the lower guide member while the upper guide member rotates, and a shaft contact member that is inserted in the upper guide member, of which the lower surface is supported by the upper end of the shaft, changing in up-down position while the cam member rotates.

[20] A control valve of claim 5 may be configured such that the first projection and the second projection are formed radially at opposite positions at a phase of 180° and two

switches that the first projection and the second projection contacts with when the rotary plate rotates are provided on the first printed circuit board.

[21] A control valve of claim 6 includes: a motor; a closing member that adjusts the opening/closing amount of a flow channel while reciprocating up/down by rotation of the motor; a cam member that integrally rotates with the motor; and a valve opening- closing amount detecting unit that detects the opening/closing amount of the closing member on the basis of output voltage according to a position that is changed along the outer circumference as the cam member rotates.

[22] A control valve of claim 7 may be configured such that the valve opening-closing amount detecting unit includes a linear magnet that changes in position along the outer circumference of the cam member while the cam member rotates, and a magnetic sensor that controls the rotation of the motor by detecting the magnetic flux density that is changed according to the position of the linear magnet.

[23] A control valve of claim 8 may be configured such that the valve opening-closing amount detecting unit uses a variable resistance.

[24] A control valve of claim 9 may be configured such that the valve opening-closing amount detecting unit uses a variable inductance.

[25] A control valve of claim 10 may be configured such that the motor is a one-way rotary motor.

[26] A control valve of claim 11 may be configured such that the motor is an alternating current motor.

[27] A method of converting a control valve of claim 12 includes: in the control valve according to claim 1, removing the constant flow operating member and the first printed circuit board; connecting the rotary plate, where a cam-shaped cam member is integrally and coaxially connected, to a shaft of the motor; and disposing a linear magnet that reciprocated up/down along the outer circumference of the cam member while the cam member rotates a magnetic sensor and a magnet sensor that controls rotation of the motor by detecting the magnetic flux density that is changed according to the position of the linear magnet.

[28] A method of converting a control valve includes: in the control valve according to claim 7, removing the linear magnet and the magnetic sensor; disposing a first printed circuit board that turns on/off the motor at the top dead center and the bottom dead center of the closing member by the first projection and the second projection formed at different distances from the center on the lower surface of the rotary plate; disposing a shaft connected with the closing member, an upper guide member that guides the shaft to reciprocate up/down therein, and a constant flow operating unit that is engaged with the outer circumference of a side of the upper guide member, of which a portion is exposed outside a case, and which allows the closing member to reciprocate up/

down by rotating the exposed portion, while the upper guide member rotates.

Advantageous Effects

[29] According to a control valve of the present invention, it is possible to simplify the structure and reduce cost by implementing one valve integrated with a constant flow control valve and an on/off type control valve. [30] Further, since components for implementing an on/off type control valve, a constant flow control valve, and a proportional control valve are provided for one valve, it is possible to simply implement a control valve integrated with on/off type and constant flow type or a proportional type control valve by replacing a portion of the components, such that it is possible to improve productivity, share the components, and reduce the manufacturing cost. [31] Further, since a flow sensor for proportional control of flow rate of heating water is not used, it is possible to prevent a control error due to contamination of a sensor, and achieve proportional control of the flow rate of heating water by using an inexpensive alternating current motor, instead of a direct current motor.

Brief Description of Drawings [32] FIG. 1 is a perspective assembly view showing a control valve according to an embodiment of the present invention.

[33] FIG. 2 is a plan view of the control valve shown in FIG. 1.

[34] FIG. 3 is an exploded perspective view of the control valve shown in FIG. 1.

[35] FIGS 4 and 5 are cross-sectional views of the control valve shown in FIG. 1.

[36] FIG. 6 is a circuit diagram schematically illustrating a connected condition of a motor and a switch in the control valve shown in FIG. 1. [37] FIG. 7 is a view illustrating magnetizing a linear magnet that is applied to the present invention. [38] FIG. 8 is a cross-sectional view illustrating converting of the control valve shown in

FIGS. 4 and 5 into a control valve integrated with constant flow type and on/off type. [39] FIG. 9 is a cross-sectional view illustrating converting of the control valve shown in

FIGS. 4 and 5 into a proportional type control valve. [40] FIGS. 10 and 11 are views illustrating an operation of setting constant flow in the control valve shown in FIG. 8. [41] FIGS. 12 and 13 are views illustrating an operation of valve-on/off in the control valve shown in FIG. 8. [42] FIGS. 14 and 15 are views illustrating an operation of proportional control in the control valve shown in FIG. 9. [43] FIG. 16 is a graph illustrating the relationship between flow rate and a potential difference of a magnetic sensor.

Best Mode for Carrying out the Invention

[44] The configuration and operation of preferred embodiments of the present invention are described hereafter in detail with reference to the accompanying drawings.

[45] FIG. 1 is a perspective assembly view showing a control valve according to an embodiment of the present invention, FIG. 2 is a plan view of the control valve shown in FIG. 1, FIG. 3 is an exploded perspective view of the control valve shown in FIG. 1, FIGS 4 and 5 are a front cross-sectional view and a side cross-sectional view of the control valve shown in FIG. 1, and FIG. 6 is a circuit diagram schematically illustrating a connected condition of a motor and a switch in the control valve shown in FIG. 1.

[46] The structure of a control valve that can achieve constant flow control function, on/ off control function, and proportional control function from one body is described with reference to FIGS. 1 to 5. However, since any one of a control valve integrated with constant flow control function and on/off control function and a proportional control valve is selective installed when a valve is practically installed, a method of converting the valve structure is described below.

[47] A control valve according to the present invention includes a motor 110, a closing member 450 that is reciprocated by rotation of the motor 110 to adjust the opening/ closing amount of heating water flow channel, a rotary plate 120 that is connected to a shaft 110a of the motor to integrally rotate and has a first projection 120a and a second projection 120b at different distances from the center on one side, a first printed circuit board 140 that turns on/off the motor at the top dead center and the bottom dead center of the closing member 450 by the first projection 120a and the second projection 120b of the rotary plate 120, a shaft 430 that has a lower end where the closing member 450 is connected, an upper guide member 320 that guides the shaft 430 to reciprocate up/ down therein, and a constant flow operating member 310 that is engaged with the outer circumference of the side of the upper guide member 320 and partially exposed outside a case 100, such that a control valve integrated with constant flow control function and on/off control function.

[48] It is preferable that the motor 110 is a one-way rotary motor that is inexpensive.

Further, the motor 110 is an alternating current motor that uses alternating power source, in which components for converting alternating current into direct current, such as a transformer and a rectifier, are not required, thereby reducing the cost as compared with using a direct current motor.

[49] The shaft 110a of the motor is inserted in a cylindrical motor shaft connecting member 111 and the motor shaft connecting member 111 is connected with the rotary plate 120 and integrally rotated.

[50] The rotary plate 120 is a cylindrical disc with prominence and depression repeatedly formed along the outer circumference. Further, a portion of the outer surface of the rotary plate 120 is exposed outside the case 100, such that a person can manually turn on/off the valve even if the motor 110 is out of order.

[51] The first projection 120a and the second projection 120b protruding from one side of the rotary plate 120 are formed at different positions in the opposite directions from the center of the rotary plate 120, that is, at a phase difference of 180°.

[52] Further, the first printed circuit board 140 equipped with a first switch 141 and a second switch 142 is disposed at a side of the rotary plate 120. The first switch 141 and the second switch 142 are disposed close to and in parallel with each other, on a circumferential path that the first projection 120a and the second projection 120b pass when the rotary plate 120 rotates.

[53] As the rotary plate 120 rotates, the first projection 120a contacts with the first switch

141 connected to the first printed circuit board 140 and the second projection 120b contacts with the second switch 142.

[54] Both of the first switch 141 and the second switch 142 that are used in this embodiment are normal close type that is normally closed.

[55] Referring to FIGS. 4 and 6, when an A-contact point of a relay 143 is electrically connected in response to a signal of a control unit 500 (the first switch 141 and the second switch 142 are normal close type, which are closed), a closed circuit is formed and alternating current is supplied to the motor 110. As the rotary plate 120 is rotated by rotation of the motor 110, the first projection 120a contacts with the first switch 141, the first switch 141 is opened and the motor 110 stops, in which the closing member 450 is positioned at the top dead center.

[56] Thereafter, when a B-contact point of the relay 143 is electrically connected in response to a signal of the control unit 500, a closed circuit is formed because the second switch 142 is closed, such that the motor 110 starts rotating again, in which the first switch 141 is changed from the open to the close.

[57] As the rotary plate 120 is rotated at 180° by the rotation of the motor 110, the second projection 120b contacts with the second switch 142 and the second switch 142 is opened, such that the motor 110 stops, in which the closing member 450 is positioned at the bottom dead center.

[58] A cam member 130 that is eccentrically disposed from the axial center is integrally connected to the rotary plate 120, such that as the motor 110 rotates, the closing member 450 reciprocates up/down along the outer circumference of the cam member 130.

[59] A configuration for transmitting the rotational motion of the cam member 130 to the linear motion of the closing member 450 is described hereafter.

[60] A cam contact member 330 that is open downward is elastically supported by a first spring 340 on the lower outer circumference of the cam member 130. The cam contact member 330 functions as a connecting member that converts the rotational motion of the cam member 130 to up-down linear motion. Therefore, as the cam member 130 rotates, the cam contact member 330 reciprocates up/down together with the closing member 450. In this configuration, the first spring 340 transmits the up-down reciprocating motion of the cam contact member 330 to the closing member 450; therefore, it needs shock-absorbing force, but does not have to be a spring.

[61] The cam contact member 330 is inserted in the upper guide member 320 and guided by the upper guide member 320 in up-down motion. The upper guide member 320 has an edge 320a protruding from center portion of the outer circumference of the cylindrical body, teeth on the outer circumference of the edge 320a, and a plurality of insertion holes 320b radially formed on the lower surface.

[62] A shaft contact member 350 is inserted at the lower portion inside the upper guide member 320. The lower end of the first spring 340 is in contact with the upper surface of the shaft contact member 350 and the center portion of the lower surface, which is recessed, is in contact with the upper end of the shaft 430.

[63] A lower guide member 420 that is inserted and fixed in a valve body 400 and has a thread on the inner circumference is disposed under the upper guide member 320.

[64] A locking rotary member 410 is inserted in the lower guide member 420 and a thread

410a formed on the outer circumference of the locking rotary member 410 is engaged with the thread formed on the inner circumference of the lower guide member 420, such that the locking rotary member 410 reciprocates up/down while rotating, such as a lead screw.

[65] A plurality of locking portions 410b protrudes upward from the upper portion of the locking rotary member 410 such that they are inserted in the insertion holes 320b of the upper guide member 320 and the locking rotary member 410 integrally rotates when the upper guide member 320 rotates.

[66] A shaft 430 is inserted in the center portion of the locking rotary member 410 and a second spring 440 is fitted on the outer surface of the shaft 430 to elastically support the inner lower surface of the locking rotary member 410.

[67] The closing member 450 that opens/closes the opening 403 formed between an inlet

401 and an outlet 402 of the heating water flow channel is connected to the lower end of the shaft 430, such that the up-down position is integrally changed with the shaft 430.

[68] A portion of the body of the constant flow operating member 310 is exposed outside the case 100 to be manually rotated and teeth are formed on the outer circumference and engaged with the edge 320a of the upper guide member 320, such that the upper

guide member 320 correspondingly rotates when the constant flow operating member 310 rotates.

[69] The case 100 is combined with the valve body 400 by a connecting member 460.

[70] A configuration needed for achieving the proportional type control valve is next described.

[71] The proportional type control valve includes a motor 110, a closing member 450 that adjusts the opening/closing amount of a flow channel while reciprocating up/down by rotation of the motor 110, a cam member 130 that integrally rotates with the motor 110, and a valve opening-closing amount detecting unit that detects the opening/ closing amount of the closing member on the basis of output voltage according to a position that is changed along the outer circumference as the cam member 130 rotates.

[72] In this configuration, the valve opening-closing amount detecting unit uses a linear magnet. That is, there are disposed a linear magnet that is elastically supported by a third spring 230 to be always in contact with the outer circumference of the cam member 130, which rotates, and changes in up-down position along the cam line of the cam member 130, a magnetic sensor 240 that is disposed close to the linear magnet 210 to control the rotation of the motor 110 by sensing magnetic flux density that is changed according to the position of the linear magnet 210, and a second printed circuit board 250 equipped with the magnetic sensor 240. The upper portion of the second spring 230 is supported by a cap 220.

[73] The 'linear magnet' described herein implies a magnet having straightness (linearity) in change of magnetic flux density, and the linear magnet 210 and the magnetic sensor 240 are described hereafter.

[74] FIG. 7 is a view illustrating magnetizing a linear magnet that is applied to the present invention, which is disclosed in Korean Patent Registration No. 660564.

[75] Referring to FIG. 7, the linear magnet 210 is magnetized such that a magnetic wall, which is an interface between the North Pole and the South Pole, produces a sine wave in the orthogonal direction from the left upper corner of a rectangle.

[76] In general, it has been known that the magnetic flux density is in inverse proportion to the square of distance. Therefore, in common magnets, changes in magnitude of the magnets according to displacement construct a quadratic function graph and do not linearity.

[77] On the contrary, as shown in FIG. 7 in which the shape of the magnet is shown by a dotted line, the magnetic flux density of the north pole according to displacement does not show linearity when the linear magnet 210 that is applied to the present invention is magnetized such that the magnetic wall is formed in the orthogonal direction; however, as shown by a solid line, the magnet is magnetized such that the magnetic wall makes a sine wave in the orthogonal direction, the magnetic flux density shows

linearity.

[78] The magnetic sensor 240 that detects changes in magnetic flux density according to changes in position of the linear magnet 210 detects the changes from PO to P 12, which is a magnet section, in which the magnetic sensor 240 detects changes in magnetic flux density according to changes in position of the linear magnet 210. That is, the magnetic sensor 240 is disposed at a predetermined distance d from the polar surface of the linear magnet 210 and the linear magnet 210 makes the polar surface move on the same plane. Accordingly, PO to P 12, which is a polar surface section of the linear magnet 210 maintain the same distance d while passing through the magnetic sensor 240, in which values of the magnetic flux density detected by the magnetic sensor 240 linearly changes. However, both ends of PO to P12, which is the polar surface section of the magnet, slightly show non-linearity; therefore, it is preferable to select P2 to PlO having good linear characteristics as a use section, except for the above portions.

[79] The magnetic sensor 240 that is used to measure changes in magnetic flux density according to changes in position of the linear magnet 210 is a hole sensor that is commonly used as one of means detecting magnetic field. When a magnetic field is vertically applied after current is applied to an electrode of a semiconductor (hole element), potential difference is generated vertical to the direction of the current and the direction of the magnetic field, such that the hole sensor can detect changes in position of the linear magnet 210 from the electric potential.

[80] FIG. 8 is a cross-sectional view illustrating conversion of the control valve shown in

FIGS. 4 and 5 into a control valve integrated with constant flow type and on/off type. That is, the proportional control function has been removed from the control valve shown in FIGS. 4 and 5. Therefore, the linear magnet 210, cap 220, spring 230, magnetic sensor 240, and second printed circuit board 250 for the proportional control are removed, and since the components have been removed, it is preferable to substitute a specific exclusive case for the case 100.

[81] FIG. 9 is a cross-sectional view illustrating conversion of the control valve shown in

FIGS. 4 and 5 into a proportional type control valve. That is, the constant flow control function and the on/off control function have been removed from the control valve shown in FIGS. 4 and 5. Therefore, the constant flow operating member 310 for the constant flow control function is removed and the first printed circuit board 140 for the on/off control function, including the first switch 141 and the second switch 142, is removed, and since the constant flow operating member 310 has been removed, it is preferable to substitute a specific exclusive case for the case 100.

[82] FIGS. 10 and 11 are views illustrating an operation of setting constant flow in the control valve shown in FIG. 8.

[83] Referring to FIG. 10, the closing member 450 is fully open. From this position, the

state shown in FIG. 11 is achieve by manually rotating the constant flow operating member 310 to reduce flow rate of the heating water. That is, as the constant flow operating member 310 and the upper guide member rotate 320 rotates, the locking rotary member 410 with the locking member 410b locked in the insertion hole 320b of the upper guide member 320 rotates. The locking rotary member 410 is moved down by the thread 410a while rotating, such that the shaft 430 and the closing member 450 move down and the opening 403 is closed. The closing amount of the opening by the closing member 450 depends on the reduced amount of heating water that is supplied to a room.

[84] FIGS. 12 and 13 are views illustrating an operation of valve-on/off in the control valve shown in FIG. 8.

[85] Referring to FIG. 12, the closing member 450 is fully open and the first projection

120a of the rotary plate 120 is in contact with the first switch 141. In this position, as shown in FIG. 6, when the B-contact point of the relay 143 is connected, the motor 110 rotates the rotary plate 120. When the rotary plate 120 rotates to 180°, as shown in FIG. 13, the second projection 120b contacts with the second switch 143, such that the motor 110 and the rotary plate 120 stop and the closing member 450 is fully closed.

[86] FIGS. 14 and 15 are views illustrating an operation of proportional control in the control valve shown in FIG. 9, and FIG. 16 is a graph illustrating the relationship between flow rate and electric potential of a magnetic sensor.

[87] Referring to FIG. 14, the closing member 450 is at the top dead center and fully open. In this position, when it is determined to need to reduce the amount of heating water on the basis of data, such as the temperature of the heating water which is measured by the heating system, the control unit 500 controls the up-down position of the closing member 450 by calculating desired flow rate and controlling the control valve. A method of controlling the control valve is described hereafter.

[88] The relationship between the flow rate and the voltage detected according to changes in position of the linear magnet 210 by the magnetic sensor 240 is pre-set in the control unit 500, as shown in FIG. 16.

[89] That is, when it is desired to obtain the maximum flow rate by fully opening the closing member 450 in the control valve, the voltage to the position of the linear magnet is set to 4.5 V, when it is desired to obtain the minimum flow rate by fully closing the closing member 450, the voltage to the position of the linear magnet 210 is set to 0.5 V, and when it is desired to obtain flow rate between the maximum and the minimum, the voltage is proportionally set due to the linearity of the linear magnet 210.

[90] Therefore, the control unit 500 sets a desired voltage for the desired flow rate on the basis of the voltage-flow rate characteristic data shown in FIG. 16, and reduces the

flow rate by rotating the motor 110 to move the closing member 450 down.

[91] In this operation, since the cam member 130 rotates with the motor 110, the linear magnet 210 moves down along the outer circumference of the cam member 130. When the potential difference that is generated in the magnetic sensor 240 according to the changes in position of the linear magnet 210 reaches the desired voltage, the control unit 500 determines that flow rate reaches the desired flow rate and stops the operation of the motor 110. Thereafter, information on the flow rate is fed-back and minute adjustment is repeatedly performed to maintain the desired flow rate.

[92] On the other hand, although it was described above that the valve opening/closing amount detecting unit uses a non-contact type linear magnet, it may be possible to substitute a variable resistance and a variable inductance for the linear magnet and the magnetic sensor.

[93] First, as for using a variable resistance, output voltage of the variable resistance according to the opening/closing amount of the valve is set in advance, such that when the contact point of the variable resistance is changed by rotation of the motor 110, it is possible to detect the opening/closing amount of the valve from the corresponding output voltage.

[94] Further, as for using a variable inductance, the output voltage of the variable inductance according to the opening/closing amount of the valve is set in advance, such that when the position of the magnet changes in a coil by rotation of the motor 110, it is possible to detect the opening/closing amount of the valve from the corresponding output voltage. Industrial Applicability

[95] As described above, the present invention implements on/off control function, constant flow control function, and proportional control function from a valve formed of one body, such that the valve can be used as control valve in a boiler system.