JP3789368B2 - Gas valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas valve that controls supply of fuel gas to a gas burner provided in a gas appliance such as a gas stove.
[0002]
[Prior art]
For example, a gas valve that drives a valve element with a motor is used for a gas appliance that enables automatic cooking by automatically adjusting the heating amount of a gas burner. In the gas valve, the gas flow rate of the fuel gas is adjusted by changing the opening degree of the valve body with respect to the valve seat provided in the internal passage of the valve casing.
[0003]
By the way, in the motor-driven gas valve, it is necessary to close the valve immediately in order to prevent the fuel gas from being held in a state where the fuel gas flows in the event of an abnormality such as a power failure or a failure of the instrument. In this case, it is proposed to attach a spiral spring to the rotating shaft of the motor and forcibly close the gas valve with the biasing force of the spring.
[0004]
In this case, since it is necessary to overcome the urging force of the spiral spring and move the valve body, a motor with a large rating is required, resulting in an increase in cost. In addition, since all the biasing force of the spring is applied to the rotating shaft of the motor during operation, the durability of the motor is reduced.
[0005]
As a solution to this problem, a magnetic body driven by a motor is provided in the internal passage of the valve casing, and the magnetic body is excited by an electromagnetic coil attached to the magnetic body to attract the valve body. However, it has been proposed to adjust the flow rate by moving the magnetic material. (For example, Unexamined-Japanese-Patent No. 2-245588). And at the time of a power failure, adsorption | suction with a magnetic body and a valve main body is cancelled | released, and an internal channel | path is closed because a valve main body seats on a valve seat.
[0006]
[Problems to be solved by the invention]
However, in this case, since the valve has a single structure, if dust or the like adheres between the valve body and the valve seat, gas leakage occurs. For this reason, in consideration of safety, it is necessary to provide a separate closing means, and there is a problem that the cost of the gas appliance is increased. Further, since the motor cannot move at the valve closing position and stops, there is a problem that a load is applied to the motor and the durability of the motor is lowered.
[0007]
Then, this invention makes it a subject to provide the gas valve which can improve durability of a motor and can lower the manufacturing cost of a gas appliance in view of the said point.
[0008]
[Means for Solving the Problems]
In order to solve this problem, the gas valve of the present invention has an internal passage, and has a valve casing having a gas inlet and a gas outlet communicating with the inner passage, and the gas outlet is surrounded by the internal passage. And a driving means for reciprocating the magnetic plunger along the internal passage by inserting a magnetic plunger including a first valve body that includes the first valve body that constitutes an on-off valve together with the first valve seat. A second valve seat located between the first valve seat and the gas outlet and surrounding the gas outlet is provided in the internal passage, and a needle valve is configured together with the second valve seat. with a second valve body, the needle body made of a magnetic material for adjusting the amount of gas to the gas outlet, retractably in the second valve seat direction is provided at the tip of the magnetic plunger, selective needle body to the magnetic plunger Adsorbing means that enables efficient adsorption While attached to the magnetic plunger, with a needle body so the needle body to the second valve body is pressed against the second valve seat needle valve closed when not adsorbed on the second valve seat direction magnetic plunger The first urging means for urging is provided.
[0009]
According to the present invention, the needle body is closest to the magnetic plunger in the closed position of the on-off valve and the needle valve . Operating the suction means in this state the needle body Ru is adsorbed to the magnetic plunger. When the driving means is driven to move the magnetic plunger, on which the needle body is attracted and held, to one side along the internal passage, the on-off valve and the needle valve are opened. In this case, the fuel gas flows into the internal passage through the gas inlet and flows out from the gas outlet. Then, the driving means is controlled to reciprocate the magnetic plunger to displace the needle body relative to the second valve seat, thereby changing the distance between the second valve body attached to the needle body and the second valve seat. The amount of gas can be adjusted by changing the opening of the needle valve .
[0010]
When the driving means is driven to move the magnetic plunger to the other side, the on-off valve and the needle valve are closed. In this case, since the gas valve has a double valve structure, a separate closing means is not required when the gas valve is provided in the gas appliance.
[0011]
Further, when abnormality such as a failure of a power failure or instrument, choose to release the adsorption of the magnetic plunger of the needle body by suction means. In this case, the needle body is moved by the urging force of the first urging means, the second valve body attached to the needle body is seated on the second valve seat, and the needle valve is closed . As a result, the supply of fuel gas is immediately shut off.
[0012]
Incidentally, when the magnetic plunger to the closed position of the opening and closing valve and the needle valve is moved, by the magnetic plunger is stopped driving the drive means can no longer be moved in its closed position is applied a load to the drive means, the durability Decreases.
[0013]
In this case, provided with a second biasing means for biasing the first valve body in a first valve seat direction, is connected to the drive means, the drive means is engaged with the magnetic plunger at the start of the drive The engaging means is provided, and the engaging means is moved by the driving means to move the magnetic plunger to the closed position of the on- off valve and the needle valve , and the first and second valve seats are moved to the first and second valve seats. When each of the valve bodies is seated, the engagement of the engagement means with the magnetic plunger may be released so that the driving force by the drive means does not act on the magnetic plunger .
[0014]
In addition, when the second urging means is provided, a motor with a large rating is required to move the magnetic plunger by overcoming the urging force of the second urging means when the on-off valve is opened, resulting in high cost. Further, all the urging force of the second urging means is applied to the rotating shaft of the motor during operation.
[0015]
Therefore, the a suction means hollow electromagnetic coil, inside the edge after the magnetic plunger is inserted in the closed position of the closing valve and the needle valve, the rear end is positioned in the hollow portion of the electromagnetic coil , set to the rear end portion of the magnetic plunger is unevenly distributed in the first valve seat direction inside the hollow portion of the magnetic coil, and Aspirate the magnetic plunger is excited electromagnetic coil into the hollow of the electromagnetic coil, the second What is necessary is just to make it a suction force work in the direction opposite to the urging force of the urging means.
[0016]
Here, in the gas valve provided with the needle valve and the opening / closing valve, the gas amount cannot be adjusted if the opening / closing valve is closed before the needle valve. In this case, when the second valve body is floated with respect to the needle body and the on-off valve and the needle valve are closed , the second valve body is moved to the second valve before the first valve body is seated on the first valve seat. The needle valve may be closed before the on-off valve is closed by sitting on the seat .
[0017]
The driving means is preferably a motor, for example.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2, reference numeral 1 denotes a gas valve according to the present invention. The gas valve 1 has a hollow cylindrical valve casing 11, and an internal longitudinal hole constitutes an internal passage 12. A gas inlet 13 is opened on the side surface of the valve casing 11 and communicates with a gas outlet 14 on the bottom surface of the valve casing 11 via an internal passage 12.
[0019]
A lid member 15 is fitted on the upper surface of the valve casing facing the gas outlet 14 via a sealing material 15a, and a rotating shaft R is connected to the internal passage 12 via the sealing material S on the upper surface of the lid member 15. A motor M is arranged so as to protrude.
[0020]
A plunger 2 that is reciprocated along the internal passage 12 by the motor M is inserted in the internal passage 12. The plunger 2 includes a cylindrical head portion 21 and a skirt portion 22 into which the rotation shaft R of the motor M is inserted.
[0021]
A first valve body 31 is attached to the head portion 21, and the first valve body 31 faces the motor M and is located on the downstream side of the gas inlet 13 and is provided in the internal passage 12. The opening / closing valve 3 is formed together with the valve 32.
[0022]
In the present embodiment, the plunger 2 is made of a magnetic material such as iron, and the hollow electromagnetic coil 4 is disposed so as to surround the skirt portion 22 of the plunger 2 so that the plunger 2 can be excited. A second valve seat 51 is provided in the internal passage 12 so as to face the motor M on the downstream side of the first valve seat 32. The needle body 52 having the second valve body 52a that constitutes the needle valve 5 together with the second valve seat 51 is selectively attracted to the lower surface of the head 21 of the plunger 2 when the plunger 2 is excited. Was arranged as follows.
[0023]
A long hole 21a in the longitudinal direction is formed in the lower surface of the head 21 and a leg piece 52b extending in the longitudinal direction is formed in the needle body 52 so that the position of the needle body 52 with respect to the plunger 2 does not shift when the plunger 2 is excited. The leg piece 52b is inserted into the long hole 21a.
[0024]
Further, when the needle valve 5 is closed, the spring 53 as the first biasing means is connected to the second valve body 52a and the head 21 so that a stable valve closing load is applied to the second valve body 52a of the needle body 52. Between the projecting portion 21b formed on the outer peripheral surface.
[0025]
Thereby, since the gas valve 1 of this invention becomes a double valve structure, when using this gas valve 1 for a gas appliance, it is not necessary to provide a closing means separately in consideration of safety. In addition, if an abnormality such as a power failure or failure occurs when the gas appliance is used, if the current does not flow through the electromagnetic coil, the excitation of the plunger 2 is released and the needle body 52 is moved to the second valve by the biasing force of the spring 53. The needle valve 5 is closed by moving in the direction of the seat 51. Thereby, supply of fuel gas can be interrupted | blocked (refer FIG. 2).
[0026]
By the way, when the plunger 2 is moved to the closed position of the on-off valve 3 and the needle valve 5, if the plunger 2 cannot move at the closed position and the driving of the motor M is stopped, a load is applied to the motor M. , Durability decreases.
[0027]
In the present embodiment, the skirt portion 22 is internally provided with a joint member 6 that is an engagement means that is screwed to the motor M and engages the plunger 2 when the motor M starts driving. In this case, the joint member 6 is formed in a hollow cylindrical shape, and is screwed to the rotation shaft R by a screw portion provided on the inner peripheral surface of the upper portion thereof. Moreover, the front-end | tip part 62 of a lower surface is bent toward the outer side.
[0028]
On the other hand, an annular stopper 22 a that engages with the tip 62 is provided on the inner wall surface of the skirt 22. When the motor M is driven from the closed position of the on-off valve 3 and the needle valve 5 to rotate the rotating shaft R in one direction, the joint member 6 screwed to the rotating shaft R moves upward, and the joint member 6 When the distal end portion 62 engages with the stopper 22a, the driving force of the motor M is transmitted to the plunger 2, and the plunger 2 moves upward along the internal passage 12.
[0029]
When the on-off valve 3 and the needle valve 5 are closed, when the motor M is driven to rotate the rotating shaft R to the other side, the plunger 2 moves downward along with the joint member 6, and the on-off valve 3 When the single valve body 31 is seated on the valve seat 32, the engagement between the distal end portion 62 and the stopper 22a is released, and the joint member 6 is movable by a predetermined distance D. This prevents an excessive load from being applied to the motor M.
[0030]
In order to apply a stable valve closing load to the first valve element 31 when the on-off valve 3 is closed, the first valve element 31 is attached in the first valve seat direction between the electromagnetic coil 4 and the first valve element 31. The spring 33 which is the second urging means for energizing is contracted. Here, when the first valve body 31 is energized by the spring 33, a motor having a large rating is required if the plunger 2 is moved by overcoming the energizing force of the spring 33 when the on-off valve 3 and the needle valve 5 are opened. Must be used.
[0031]
In the present embodiment, the position of the skirt portion 22 located in the hollow electromagnetic coil 4 at the closed position of the on-off valve 3 and the needle valve 5 is unevenly distributed on the gas outlet 14 side, and the plunger 2 is adsorbed by the electromagnetic coil 4. Then, a suction force works in the direction opposite to the biasing force of the spring 33.
[0032]
By the way, when the gas valve 1 is formed as in the present embodiment, in order to control the gas flow rate to the gas outlet 14 to a fine flow rate, the open / close valve 3 is closed after the needle valve 5 is closed. There is a need.
[0033]
In the present embodiment, the second valve body 52a is slid vertically in an annular groove G provided on the outer peripheral surface of the needle body 52 so that the needle body 52 and the second valve body 52a are movable relative to each other. I attached it freely. When the needle valve 5 is closed, the needle body 52 is inserted into the valve hole of the second valve seat 51.
[0034]
Next, the operation of the gas valve 1 of the present invention will be described. In FIG. 3A, the on-off valve 3 and the needle valve 5 are each in the closed position. In this state, the fuel gas does not flow to the gas outlet 14. In order to open the on-off valve 3 and the needle valve 5 from this state, the plunger 2 is excited by the electromagnetic coil 4 to attract the needle body 52 to the plunger 2.
[0035]
Next, when the motor M is driven to rotate the rotating shaft R to one side, the joint member 6 screwed to the rotating shaft R moves upward. When the distal end portion 62 of the joint member 6 engages with the stopper 22a, the driving force of the motor M is transmitted to the plunger 2, and the plunger 2 moves upward along the internal passage 12. In this case, the on-off valve 3 is first opened, and the needle body 52 inserted into the valve hole moves upward.
[0036]
When the needle body 52 moves along with the movement of the plunger 2 and the second valve body 52a comes into contact with the lower end of the groove G of the needle valve 5, the second valve body 52a moves along with the movement of the plunger 2. Is separated from the second valve seat 51, and the needle valve 5 is opened.
[0037]
When the motor M is driven to further rotate the rotary shaft R in one direction, the motor M reaches the position where the opening between the second valve seat 51 and the needle body 52 is maximized (see FIG. 3B). In this case, the gas flow rate of the fuel gas to the gas outlet 14 is maximized.
[0038]
Next, the plunger 2 is reciprocated along the internal passage by the motor M, and the opening between the second valve seat 51 and the needle body 52 is changed to control the gas flow rate of the fuel gas. FIG. 3C shows the minimum throttle position of the gas flow rate.
[0039]
Next, when the on-off valve 3 and the needle valve 5 are closed, when the motor M is driven to rotate the rotating shaft R to the other side, the plunger 2 moves downward along with the joint member 6. Then, the second valve body 52a is seated on the second valve seat 51, and the needle valve 5 is first closed (see FIG. 3D). In this case, the supply of the fuel gas to the gas outlet 14 is interrupted.
[0040]
When the rotation shaft R is further rotated to the other side, the first valve body 31 is seated on the first valve seat 32 and the on-off valve 3 is closed. At that time, the engagement between the tip 62 and the stopper 22a is released, and the downward movement of the plunger 2 is stopped, but the joint member 6 moves by a predetermined distance D (FIGS. 3E and 3). (See (a)). Until the movement of the plunger 2 stops, the needle body 52 moves downward by the gap G1 after the second valve body 52a is mounted in the groove G while being inserted into the valve hole.
[0041]
When the on-off valve 3 and the needle valve 5 are closed, the driving of the motor M is stopped.
[0042]
As shown in FIG. 4, in order to detect the position of the plunger 2, one end of the joint member 6 may be extended above the lid member 15, and a position detection means D may be provided correspondingly. In this case, if the position of the joint member 6 corresponding to the set flow rate is stored and the motor M is controlled so that the joint member is adjusted to that position in accordance with the heating power adjustment signal, the gas flow rate can be easily adjusted.
[0043]
At this time, if a stepping motor is used as the motor M, the flow rate can be finely adjusted.
[0044]
In addition, as shown in FIG. 5, a pressure sensor PG that measures the pressure in the vicinity of the gas outlet 14 may be provided. In this case, a pressure value corresponding to the set flow rate may be stored, and the gas flow rate may be adjusted by controlling the motor M from the detected value of the pressure sensor PG and the set pressure value in accordance with the heating power adjustment signal.
[0045]
Furthermore, in the above-described embodiment of the invention, the electromagnetic coil 4 is provided so as to surround the skirt portion 22 of the plunger 2, but the electromagnetic coil 40 is connected to the needle body 52 of the needle valve 5 as shown in FIG. 6. It can also be provided around.
[0046]
In this case, the spring SP may be contracted in the long hole 21a so that the needle body 52 is urged toward the gas outlet 14 at the time of a power failure.
[0047]
【The invention's effect】
As described above, in the gas valve of the present invention, it is difficult to apply a load to the motor, the durability thereof can be increased, and the manufacturing cost of the gas appliance can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a gas valve according to the present invention. FIG. 2 is a cross-sectional view illustrating a state during a power failure according to the present invention. .
4 is a cross-sectional view illustrating a first modification of the gas valve of the present invention. FIG. 5 is a cross-sectional view illustrating a second modification of the gas valve of the present invention. FIG. 6 is a third modification of the gas valve of the present invention. Cross-sectional view to explain 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Gas valve 11 Valve casing 12 Internal passage 2 Plunger 3 On-off valve 31 1st valve body 32 1st valve seat 33 Spring 4 Coil 5 Needle valve 51 2nd valve seat 52 Needle main body 52a 2nd valve body

Claims (5)

A valve casing provided with an internal passage and having a gas inlet and a gas outlet communicating with the internal passage; a first valve seat surrounding the gas outlet is provided in the internal passage; And a gas valve provided with a driving means for reciprocating the magnetic plunger along the internal passage by inserting a magnetic plunger having a first valve body constituting an on-off valve together with the internal passage,
A second valve seat that is located between the first valve seat and the gas outlet in the internal passage and surrounds the gas outlet, and a second valve body that constitutes a needle valve together with the second valve seat ; A needle body made of a magnetic material that adjusts the amount of gas to the gas outlet is provided at the tip of the magnetic plunger so as to be able to advance and retract in the direction of the second valve seat. means as well as attached to the magnetic plunger, the needle body so that the second valve body is a needle valve is pressed against the second valve seat is closed second valve seat direction when the needle body in the magnetic plunger is not attracted A gas valve characterized in that a first urging means for urging is provided. Second biasing means for biasing the first valve body provided with a first valve seat direction, is connected to the drive means, engaging said drive means is engaged with the magnetic plunger at the start of the drive The magnetic plunger is moved to the closed position of the on- off valve and the needle valve by moving the engaging means by the driving means , and the first and second valve seats are moved to the first and second valve seats. When the body is seated, respectively, to release the engagement between the magnetic plunger of the engaging means, a gas valve of claim 1, wherein the driving force by the driving means is characterized in that so as not to act on the magnetic plunger. Wherein a suction means hollow electromagnetic coil, inside the edge after the magnetic plunger is inserted in the closed position of the closing valve and the needle valve, the rear end is positioned in the hollow portion of the electromagnetic coil, the magnetic plunger of the rear end portion is set to be unevenly distributed in the first valve seat direction inside the hollow portion of the magnetic coil, and Aspirate the magnetic plunger is excited electromagnetic coil into the hollow of the electromagnetic coil, the second biasing means The gas valve according to claim 2, wherein a suction force acts in a direction opposite to the urging force. When the second valve body is floated with respect to the needle body and the on-off valve and the needle valve are closed , the second valve body is seated on the second valve seat before the first valve body is seated on the first valve seat. to, gas valve according to any one of claims 1 to 3 needle valve before the closing valve is closed is characterized in that as closed. It said drive means is a gas valve according to any one of 請 Motomeko 1 to claim 4 you being a motor.

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