JP2014020410A - Electric diaphragm valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a diaphragm by preventing occurrence of torsion.SOLUTION: An electric diaphragm valve includes: a valve case 110 including a valve chamber 113 and a valve seat 114 provided to a one-end side end wall 113a of the valve chamber in its inside; a diaphragm 120 attached to the other end side end surface of the valve chamber; a valve element part 130 provided to the diaphragm so as to be opposed to the valve seat; a motor 140; and a feed screw mechanism 150 for displacing the diaphragm so that the valve element part approaches or is separated from the valve seat by forward/reverse rotation of the motor. In the electric diaphragm valve, an output member 152 of the feed screw mechanism 150 to be advanced/retreated in an axial direction and the diaphragm 120 are coupled to each other so as to be freely relatively rotated. Even when the output member 152 is rotated only by a portion of slide clearance between itself and a guide member 117 for stopping its rotation, rotating force is not transmitted to the diaphragm 120 and torsion of the diaphragm 120 is prevented.

Description

  The present invention relates to an electric diaphragm valve used in a gas appliance or the like.

  Conventionally, as this type of electric diaphragm valve, a valve housing having a valve chamber and a valve seat provided on an end wall of one end of the valve chamber, a diaphragm mounted on an end surface on the other end side of the valve chamber, and a valve It is known to include a valve body portion provided on a diaphragm so as to face the seat, a motor, and a feed screw mechanism that displaces the diaphragm so that the valve body portion approaches and separates from the valve seat by forward and reverse rotation of the motor. (For example, refer to Patent Document 1). In this configuration, the output member of the feed screw mechanism that advances and retreats in the axial direction is fixed to the diaphragm so that the diaphragm is displaced together with the output member.

By the way, the output member of the feed screw mechanism is prevented from rotating by the guide member and moves only in the axial direction. However, it is necessary to secure a clearance that allows the output member to slide between the output member and the guide member, and the output member rotates by this clearance when the motor is switched between forward rotation and reverse rotation. .
Conventionally, since the output member is fixed to the diaphragm, there is a problem that the diaphragm is twisted by the rotation of the output member and durability is deteriorated.

Japanese Patent Laying-Open No. 2007-224984 (FIG. 6)

  In view of the above points, an object of the present invention is to provide an electric diaphragm valve capable of improving the durability by preventing twisting of the diaphragm.

  In order to solve the above problems, the present invention includes a valve housing having a valve chamber and a valve seat provided on an end wall of one end of the valve chamber, a diaphragm attached to an end surface on the other end side of the valve chamber, Electric diaphragm valve comprising: a valve body portion provided on the diaphragm so as to face the valve seat; a motor; and a feed screw mechanism that displaces the diaphragm so that the valve body portion approaches and separates from the valve seat by forward and reverse rotation of the motor. In this embodiment, the output member of the feed screw mechanism that advances and retreats in the axial direction and the diaphragm are connected so as to be relatively rotatable.

  According to the present invention, even if the output member rotates by the sliding clearance between the output member and the guide member that prevents the rotation of the output member, the output member can rotate relative to the diaphragm. Power is not transmitted. Accordingly, it is possible to improve durability by preventing the diaphragm from being twisted.

  Even when the output member is merely brought into contact with the diaphragm, the diaphragm can be pressed against the output member by the gas pressure in the valve chamber acting on the diaphragm, and the diaphragm can be displaced following the advance and retreat of the output member. This case is also included in the above-described “the output member and the diaphragm are connected to each other so as to be relatively rotatable”. However, if the output member is brought into direct contact with the diaphragm, there is a possibility that the diaphragm is slightly twisted due to transmission of rotational force due to friction between the diaphragm and the output member. For this reason, it is desirable to fix a hard plate on the outer surface of the diaphragm and to bring the output member into contact with the hard plate. According to this, friction with the output member can be reduced, and the twisting of the diaphragm can be prevented more reliably.

  By the way, if the valve body part adheres to the valve seat while the valve is closed, the output member may be moved in the opening direction (the direction in which the valve body part is separated from the valve seat) only by contacting the output member with the diaphragm. There is a possibility that the diaphragm does not follow and displaces and cannot be opened.

  On the other hand, a spring for urging the diaphragm in the opening direction is provided, or a hooking portion for the diaphragm is provided on the output member so that the traction force in the opening direction is transmitted to the diaphragm by the movement of the output member in the opening direction. If provided, the valve body portion can be opened even if it adheres to the valve seat, which is advantageous.

Sectional drawing of the gas stove which uses the electric diaphragm valve of embodiment of this invention. The flowchart which shows the content of the temperature control performed with the gas stove of FIG. Sectional drawing of 1st Embodiment of an electrically driven diaphragm valve. Sectional drawing cut | disconnected by the IV-IV line of FIG. Sectional drawing of 2nd Embodiment of an electrically driven diaphragm valve.

  Referring to FIG. 1, reference numeral 1 denotes a top plate that covers the upper surface of a stove body (not shown). The top plate 1 is provided with a burner opening 1a, and a burner 2 is installed on the stove body so as to face the burner opening 1a. On the top plate 1, a virtues 3 formed by attaching a plurality of virtuosity claws 32 radially to an annular virtuosity frame 31 so as to surround the burner 2, and cooking containers such as pots placed on the virtues 3 Is heated by the burner 2.

  The burner 2 is mounted on the burner body 22, which is connected to the mixing tube 21, and an annular burner cap 23 that is placed on the burner body 22 and defines a flame opening 23 a between the burner body 22 and the burner cap 23. It is comprised by the well-known annular burner provided with the cyclic | annular secondary air guide plate 24 which is mounted in this and defines a secondary air path between the burner caps 23. An ignition electrode 25 and a thermocouple 26 for flame detection are attached to the outer periphery of the burner 2.

  In the gas supply path 4 to the burner 2, in order from the upstream side, an electromagnetic safety valve 41 that closes when the electromotive force of the thermocouple 26 falls below a predetermined level due to the misfire of the burner 2, and the front of the stove body are not shown. A manual main valve 42 that is opened by an ignition operation by an operation button and closed by a fire extinguishing operation, a manual flow rate adjustment valve 43 that is linked to a heating power adjustment lever (not shown) on the front of the stove body, a control valve 44, and a control An orifice 45 in parallel with the valve 44 is provided.

  Further, a pan bottom temperature sensor 5 that protrudes above the burner 2 through a burner inner space surrounded by the burner 2 is installed. The pan bottom temperature sensor 5 includes a support pipe 51 that is vertically long and inserted into the burner inner space, and a thermal head 52 that is supported by the upper end of the support pipe 51. The support pipe 51 is fixed to the burner 2 with a fixture (not shown). The thermal head 52 includes a heat collecting plate 52a that comes into contact with the bottom surface of the cooking container, an inner cylinder 52b whose upper end is closed by the heat collecting plate 52a, and an outer cylinder 52c for heat insulation that surrounds the inner cylinder 52b. A thermal element 53 such as a thermistor for detecting the temperature of the cooking container is attached to the lower surface of the hot plate 52a via the heat collecting plate 52a.

  The inner cylinder 52b is externally inserted in a spring receiver 54a fixed to the upper end of the support pipe 51 so as to be movable up and down. A spring 54 is interposed between the spring receiver 54a and the heat collecting plate 52a so as to support the support pipe. A thermal head 52 is biased upward by a spring 54 with respect to 51. Further, a stepped portion 52d having a reduced diameter is formed at the lower end portion of the inner cylinder 52b. When the cooking container is not placed on Gotoku 3, the thermal head 52 contacts the lower surface of the spring receiver 54a with the stepped portion 52d. It is held at the upper moving end position regulated by contact. At the upper moving end position, the thermal head 52 protrudes above the virtues 3. When the cooking container is placed on Gotoku 3, the thermal head 52 comes into contact with the bottom surface of the cooking container and is pushed down against the biasing force of the spring 54, and the heat collecting plate 52a is cooked by the compression reaction force of the spring 54. The bottom surface of the container is surely contacted.

  The lead wire 53a extending from the heat sensitive element 53 is inserted into the support pipe 51, pulled out from the lower end thereof, and connected to the controller 6 as control means (see FIG. 1). A heat insulating coating 53b is externally attached to the lead wire 53a.

  The controller 6 performs temperature control based on the temperature detected by the pan bottom temperature sensor 5 (thermal element 53) when the temperature control mode is selected as the heating mode by the operation unit on the stove front surface. In the temperature control, as shown in FIG. 2, in STEP 1, it is determined whether or not the detected temperature T of the pan bottom temperature sensor 5 is equal to or higher than the upper limit temperature YTmax of a predetermined set temperature range, and when T ≧ YTmax, Proceeding to STEP 2, the control valve 44 is closed. Next, proceeding to STEP 3, it is determined whether or not the detected temperature T of the pan bottom temperature sensor 5 has become equal to or lower than the lower limit temperature YTmin of the set temperature range. When T ≦ YTmin, the routine proceeds to STEP 4 and the control valve 44 is opened. After making the valve, return to STEP1.

  When the control valve 44 is closed, the amount of gas supplied to the burner 2 is limited to the minimum gas amount defined by the orifice 45, and the cooking vessel temperature detected by the pan bottom temperature sensor 5 gradually decreases due to a decrease in the heating power of the burner 2. . Here, when the set temperature range is set to a relatively low temperature, in order to reduce the overshoot of the cooking container temperature with respect to the upper limit temperature YTmax and improve the temperature control performance, the minimum gas amount defined by the orifice 45 Is desired to be as small as possible. However, when the amount of gas supplied to the burner 2 is rapidly reduced by closing the control valve 44, the burner 2 is likely to be misfired. Therefore, the control valve 44 is constituted by the electric diaphragm valve 100 shown in FIG. 3 so that misfire can be prevented even if the minimum gas amount defined by the orifice 45 is set as small as possible.

  The electric diaphragm valve 100 includes a valve housing 110 having a gas inlet 111 and a gas outlet 112. Inside the valve housing 110, there are a valve chamber 113 communicating with the gas inlet 111, a valve seat 114 provided on one end wall 113 a of the valve chamber 113, and a valve chamber 113 and a gas outlet 112 formed in the valve seat 114. And a valve hole 115 that communicates with each other.

  Further, a passage hole 116 is formed in the valve housing 110 in parallel with the valve hole 115, which communicates the valve chamber 113 and the gas outlet 112, and an orifice 45 is provided in the passage hole 116. That is, a part of the passage hole 116 is formed in a small diameter hole that becomes the orifice 45.

  The electric diaphragm valve further includes a diaphragm 120 attached to an end face on the other end side of the valve chamber 113, a valve body 130 provided on the diaphragm 120 so as to face the valve seat 114, a motor 140 including a stepping motor and the like. And a feed screw mechanism 150 that displaces the diaphragm 120 so that the valve body 130 approaches and separates from the valve seat 114 by forward and reverse rotation of the motor 140.

  A diaphragm cover 117 is attached to the outer surface of the valve casing 110 so that the peripheral edge of the diaphragm 120 is sandwiched between the valve casing 110 and the motor 140 is mounted on the outer end of the diaphragm cover 117, and the diaphragm cover 117. The feed screw mechanism 150 is disposed inside the. The feed screw mechanism 150 includes a screw shaft 151 on the output shaft of the motor 140 and a nut 152 that is screwed onto the screw shaft 151. As shown in FIG. 4, the outer shape of the nut 152 is non-circular, and the nut 152 is slidably accommodated in a state where the nut 152 is prevented from rotating in a diaphragm cover 117 having a non-circular cross section. Thus, the nut 152 as an output member advances and retreats in the axial direction by forward and reverse rotation of the screw shaft 151 by the motor 140.

  Here, the electric diaphragm valve 100 is closed from the open state over a certain amount of time due to the rotation of the motor 140. Therefore, even if the minimum gas amount defined by the orifice 45 is set to be very small, the amount of gas supplied to the burner 2 can be gradually reduced when the electric diaphragm valve 100 serving as the control valve 44 is closed to prevent misfire. Therefore, the minimum gas amount can be set as small as possible, and even when the set temperature range is set to a relatively low temperature, overheating of the cooking container temperature with respect to the upper limit temperature can be reduced to improve the temperature control performance.

  In addition, the electric diaphragm valve 100 only energizes the motor 140 during the opening / closing operation, and is maintained in the valve open state and the valve closed state without being energized, so that power consumption can be reduced. Further, the electric diaphragm valve 100 is different from a normal electric valve not provided with a diaphragm, and the arrangement portion of the feed screw mechanism 150 is hermetically sealed by the diaphragm 120 with respect to the valve chamber 113. It is not necessary to incorporate a seal member for preventing gas leakage to the bottom. Therefore, power loss due to friction with the seal member does not occur, and power consumption can be reduced as compared with a normal motor-operated valve. Therefore, the use of the electric diaphragm valve 100 as the control valve 44 is particularly advantageous when the power source is a dry battery.

  By the way, it is possible to fix the nut 152 which is an output member of the feed screw mechanism 150 to the diaphragm 120. However, in this case, when the motor 140 is switched between normal rotation and reverse rotation, the nut 152 prevents the nut 152 from rotating. When rotating by the amount corresponding to the sliding clearance with the diaphragm cover 117 (rotation between the solid line and the phantom line in FIG. 4), the diaphragm 120 is twisted and the durability deteriorates.

  Therefore, in the present embodiment, the nut 152 and the diaphragm 120 are connected so as to be rotatable relative to each other. More specifically, a metal or resin hard plate 121 is fixed to the outer surface of the diaphragm 120, and the tip of the nut 152 is brought into contact with the hard plate 121. According to this, even if the nut 152 rotates by the sliding clearance, the nut 152 rotates and slides with respect to the hard plate 121, and the rotational force of the nut 152 is not transmitted to the diaphragm 120. Therefore, it is possible to prevent the diaphragm 120 from being twisted and improve durability.

  Although the nut 152 can be brought into direct contact with the diaphragm 120, in order to reduce the friction with the nut 152 and to prevent the diaphragm 120 from being twisted more reliably, as in this embodiment. It is desirable to bring the nut 152 into contact with the hard plate 121.

  In the present embodiment, a spring 160 is disposed between the diaphragm 120 and the end wall 113a of the valve chamber 113 to urge the diaphragm 120 in the opening direction (the direction in which the valve body 130 is separated from the valve seat 114). ing.

  Here, since the diaphragm 120 is pressed in the opening direction by the gas pressure in the valve chamber 113, the hard plate 121 is pressed against the nut 152 without following the spring 160, and follows the forward / backward movement of the nut 152. The diaphragm 120 can be displaced. However, when the valve element 130 adheres to the valve seat 114 during the valve closing, the diaphragm 120 does not follow and displace even if the nut 152 is moved in the opening direction, and the valve cannot be opened. On the other hand, if the spring 160 is provided as in the present embodiment, the valve body 130 can be opened even if it adheres to the valve seat 114, which is advantageous.

  Next, the electric diaphragm valve 100 of 2nd Embodiment shown in FIG. 5 is demonstrated. The basic structure of the electric diaphragm valve 100 is not particularly different from that of the electric diaphragm valve 100 of the first embodiment, and the same members and parts as those of the first embodiment are denoted by the same reference numerals. Yes.

  In the electric diaphragm valve 100 of the second embodiment, the nut 152 is provided so that the traction force in the opening direction is transmitted to the diaphragm 120 by the movement of the nut 152 in the opening direction without providing the spring 160 of the first embodiment. A hooking portion 153 for the diaphragm 120 is provided. Specifically, a protrusion 122 having a huge head 122a is provided at the center of the outer surface of the rigid plate 121 fixed to the diaphragm 120, and a hook that can be engaged with the huge head 122a is provided on the inner periphery of the tip of the nut 152. A portion 153 is formed.

  In the second embodiment, when the valve body 130 adheres to the valve seat 114 during the valve closing, the hook 152 is engaged with the enormous head 122a by the movement of the nut 152 in the opening direction, and the diaphragm 120 is moved. Pulled in the opening direction. Therefore, even if the valve body 130 adheres to the valve seat 114, the valve can be opened.

  Instead of fixing the rigid plate 121 to the diaphragm 120, a protrusion having a huge head that can be engaged with the hook portion 153 provided on the nut 152 may be provided at the center of the outer surface of the diaphragm 120.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above embodiment, the output member of the feed screw mechanism 150 that advances and retracts in the axial direction is configured by the nut 152, but the nut is rotated by the motor 140, and the screw shaft that is screwed into the nut advances and retracts in the axial direction. The feed screw mechanism 150 may be configured to be an output member.

  Moreover, although the said embodiment applies this invention to the electric diaphragm valve 100 used as the control valve 44 controlled to open and close based on the detection temperature of the pan bottom temperature sensor 5, the present invention is applied to the electric diaphragm valve for other uses. Similarly, the present invention can be applied.

  DESCRIPTION OF SYMBOLS 100 ... Electric diaphragm valve, 110 ... Valve housing, 113 ... Valve chamber, 113a ... End wall, 114 ... Valve seat, 120 ... Diaphragm, 121 ... Hard plate, 130 ... Valve body part, 140 ... Motor, 150 ... Feed screw Mechanism: 152 ... Nut (output member), 153 ... Hook, 160 ... Spring.

Claims (4)

A valve casing having a valve chamber and a valve seat provided on one end wall of the valve chamber inside, a diaphragm mounted on an end face on the other end side of the valve chamber, and a valve provided on the diaphragm so as to face the valve seat In an electric diaphragm valve comprising a body part, a motor, and a feed screw mechanism that displaces the diaphragm so that the valve body part approaches and separates from the valve seat by forward and reverse rotation of the motor.
An electric diaphragm valve characterized in that an output member of a feed screw mechanism that advances and retreats in an axial direction and a diaphragm are connected so as to be relatively rotatable.   2. The electric diaphragm valve according to claim 1, wherein a hard plate is fixed to an outer surface of the diaphragm, and the output member is brought into contact with the hard plate.   3. The gas stove according to claim 1, further comprising a spring that biases the diaphragm in the opening direction with a direction in which the valve body part is separated from the valve seat as an opening direction.   A direction in which the valve body part is separated from the valve seat is an opening direction, and the output member is moved in the opening direction so that a pulling force in the opening direction is transmitted to the diaphragm. The gas stove according to claim 1 or 2, wherein is provided.

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