JP3091952B2 - Gas appliance thermal power control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal power control apparatus for a gas appliance provided with a throttle valve for adjusting the thermal power by increasing or decreasing the amount of gas supplied to a burner by reciprocating between a high heat position and a low heat position. About.

[0002]

2. Description of the Related Art In general, when gas is supplied to a burner, gas is injected at a high speed from a nozzle into a mixing pipe located on the upstream side of a flame hole of the burner, and is sucked into the mixing pipe by an ejector effect due to the gas injection. The air and gas around the nozzle are mixed in a mixing pipe to form a mixture and supply the mixture to a burner. In such a type of gas appliance, the heating power is adjusted by increasing or decreasing the gas injection amount. However, when the gas injection amount increases or decreases, the air suction amount also changes. That is, if the gas injection amount decreases, the air suction amount also decreases, and if the gas injection amount increases, the air suction amount also increases. Be kept constant.

However, if the thermal power is rapidly adjusted, the air-fuel ratio may temporarily deviate from the normal value. In particular, if the heating power is rapidly reduced from a high heat to a low heat, the rate of decrease of air cannot follow the rate of decrease of gas due to inertia, and the ratio of air to gas is large, that is, the mixture becomes thin, and the amount of mixture decreases. There is a danger of misfiring due to the decrease in itself.

[0004] In order to solve such a problem,
As disclosed in Japanese Patent Application No. 6-88416, a cylindrical portion is formed on a fixed member, a throttle valve is extended and inserted into the cylindrical portion, and grease is filled between the two. A coil spring surrounding the throttle valve is contracted in between, and the coil spring urges the throttle valve in the low flame direction, and abuts a pin protruding from the throttle valve to adjust the position of the throttle valve in the low flame direction. One having a cam surface that regulates at a predetermined position was proposed earlier.

[0005]

However, in the above-mentioned proposal, the throttle valve must be inserted into the cylindrical portion and a space for contracting the coil spring must be provided. Therefore, there is a problem that the size of the thermal power control device is increased.

In view of the above-mentioned problems, the present invention has been made in view of the above-mentioned problems, and even if the operating mechanism for adjusting the heating power is suddenly operated to the low fire side, the burner misfires without stopping the movement of the operating mechanism on the way. It is an object of the present invention to provide a thermal power control device for a gas appliance that can prevent the occurrence of fire without increasing the size.

[0007]

In order to achieve the above object, a pin is protruded from a throttle valve which is rotatable and reciprocable and adjusts a gas flow rate by reciprocating movement, according to a rotation position of the throttle valve. a cam surface for regulating the movement in the low heat direction of the throttle valve at a predetermined position was, be one free end provided with a spring for biasing the contact with the throttle valve in the pin to simmer direction, the spring
Of the throttle valve to move the throttle valve rapidly to the low heat direction.
The above-mentioned pin separates from the cam surface when the valve is turned
Is set to a size that allows
If the throttle valve is turned away from the
The edge that moves the throttle valve in the low heat direction faces the cam surface
It is characterized by being formed .

There is no need to lengthen the throttle valve by engaging the spring with the pin.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a thermal power control device for controlling the amount of gas supplied to a mixing pipe 42 located upstream of a burner hole of a burner. Is injected from the supply path 12 into the mixing pipe 10b through the nozzle 10a, and the surrounding air and gas sucked by the ejector effect are mixed to form a mixture, which is supplied to the burner. This device is a well-known device in which when a fire extinguishing button 13 for performing a fire extinguishing of a burner is pressed, an electromagnetic safety valve 15 is opened, and a main valve 16 is kept open by a push-push mechanism 14.

To explain this further, the fire extinguishing button 13
Sliding body 13 pushed against spring 13a by pushing operation
b, the rod 15a of the electromagnetic safety valve 15 and the main valve 1
6 is pushed and the electromagnetic safety valve 15 and the main valve 16 are both opened. Here, when the pressing operation on the point fire extinguishing button 13 is released, the sliding body 13b is pushed back by the urging force of the spring 13a, but the locking pin 14b is locked in the middle locking position of the heart cam groove 14a formed in the sliding body 13b. Then, the sliding body 13b is temporarily locked at an intermediate locking position in the middle. At this time, the main valve 16 is in a valve-open state because the rod 16a is in contact with the distal end surface of the sliding body 13b.
On the other hand, the rod 15a of the electromagnetic safety valve 15 is separated from the distal end face, but is attracted and held by the thermoelectromotive force of a thermocouple (not shown). When the fire is extinguished, pressing the point fire extinguishing button 13 again causes the locking pin 14b to operate.
Is disengaged from the intermediate locking position of the heart cam groove 14a, and the sliding body 13b returns to the original position by the urging force of the spring 13a.
As a result, the main valve 16 is closed, so that gas is not supplied to the burner and the fire is extinguished. Then, the thermoelectromotive force from the thermocouple disappears, and the electromagnetic safety valve 15 is not kept open and closed.

The control for increasing or decreasing the amount of gas supplied from the supply path 12 to the burner is performed by raising and lowering a throttle valve 17. The throttle valve 17 is provided with an O-ring 17b.
When the throttle valve 17 rises against the sliding resistance of the ring 17b, the gas passage area of the portion where the throttle valve 17 is provided increases, and conversely, when the throttle valve 17 descends, the passage area decreases. The throttle valve 17 is provided with a pin 17a projecting therefrom. The pin 17a is inserted into an opening window 3 formed in a guide plate 18, and a lower edge of the opening window 3 constitutes a cam surface described later. . The thermal power control device 1 is provided with a lever 2 pivotally supported by a fulcrum pin 21. The pin 17a is inserted into a longitudinally long groove 22 formed in the lever 2 in the longitudinal direction. Have been. The spring 4 is attached to the guide plate 18 which is a cam plate, and the cantilevered spring portion 41 of the spring 4 constantly urges the pin 17a downward, that is, in the direction of weak ignition of the throttle valve 17. .

The spring 4 is made of a spring steel wire formed into the shape shown in FIG. 2, and has a base portion 43 connected to the spring portion 41 in contact with the pin 17a via a curved portion 42. An engaging portion 44 is formed to project in a direction perpendicular to a plane including the base 43. And
As shown in FIG. 3, while the curved portion 42 is hooked on the L-shaped engaging protrusion 18 b on the side of the opening window 3 on the guide plate 18, a slit-shaped slit formed on the guide plate 18 above the opening window 3. The engaging portion 44 is pushed into the engaging window 18a while being elastically deformed, and the spring 4 is held on the guide plate 18 with one touch. Since the spring 4 is held on the guide plate 18 by its own shape in this way, no separate member for holding the spring 4 is required. Further, when the spring 4 is detached, only the base 43 is pulled and a tool is used. It can be easily removed without it. By the way, when the spring 4 is held by the holding plate 18, the spring portion 41 contacts the upper surface of the pin 17 a, and
a is urged downward.

As shown in FIG. 4, the opening window 3 is
A cam surface including a first, a first inclined portion 32 and a second inclined portion 33 is provided, and the pin 17 a is pressed against the cam surface by the spring 4. The long groove 22 is located on the left side in the figure and the pin 17a
Is located in the horizontal portion 31, the throttle valve 17 is pulled up to the MAX position, which is the rising end, and the burner enters a high-fire state. In this state, the lever 2 is swung to make the long groove 2
When the pin 17a is moved to the right in the figure, the pin 17a moves from the horizontal portion 31 to the first inclined portion 32, and further moves the long groove 22 to the right to move along the second inclined portion 33 to the MIN position which is the descending end. It descends and the burner becomes low heat. When the long groove 22 is moved at a normal speed, the pin 17
a does not separate from the cam surface due to the urging force of the spring 4, but when the lever 2 is quickly operated to move the long groove 22 to the right side in FIG. 4 at a high speed, the aperture is restricted against the sliding resistance of the O-ring 17b. The pin 17a cannot always be pressed against the cam surface by the urging force of the spring 4 for moving the valve 17 in the low heat direction. When the long groove 22 moves to the right end in the figure, the pin 17a is higher than the MIN position. Α
It will be in a state of lowering only to the position. In this state, since the pin 17a is not supported from below, the pin 17a descends to the MIN position at a constant speed by the urging force of the spring 4. Therefore, the pin 17a descends at such a speed as not to misfire without following the rapid operation of the lever 2 in the low-fire direction. Note that the upper edge 34 of the opening window 3 is formed so as to be separated upward and rightward from the cam surface so as not to restrict such movement of the pin 17a in the opening window 3. When the lever 2 is operated from the low heat state to the high heat state, the pin 17a moves along the cam surface.

In the above embodiment, the spring 4 is formed in a cantilever shape, but may be formed in a cantilever shape as shown in FIG. In this embodiment, both ends of the spring 4a are inserted into the engagement holes 18c provided in the guide plate 18C to hold the spring 4a. Both ends of the spring 4a are rotatably held with respect to the engagement hole 18c, so that the bending allowance of the spring 4a can be long. As shown in FIG. 6, one end of the torsion spring 4b is rotatably inserted and held in the engagement hole 18c, and the other end is also rotatably wound around the pin 17a.
a may be urged to be constantly pulled downward. It is desirable that the pin 17a is formed with a concave groove over the entire circumference so that the other end of the torsion spring 17a does not come off.

By the way, the present invention shown in each of the above embodiments can be applied to the type shown in FIG. In the illustrated example, when the point fire extinguishing button 13 is pressed, the standing piece 13 c formed on the sliding body 13 b pushes the power point 51 at the lower end of the link 5 to rotate the link 5. Then, the long groove 52 formed in the vicinity of the upper end of the link 5 moves the pin 17a, and forcibly sets the throttle valve to a high-fire state. In this embodiment, the lever 2 is swingably attached to the upper surface of the guide plate 18 by a caulking pin 19, and the lever 2 is cooperated with the groove 23 of the lever 2 and the fulcrum 53 at the upper end of the link 5. Is forcibly moved to the high heat position. In this type, even if the lever 2 is set to the low heat position before ignition, if the ignition is performed by pressing the fire extinguishing button 13, the lever 2 is forcibly set to the high heat position. May be returned to the low-fire position. In such a case, it is possible to prevent misfire in the burner by applying the present invention.

[0016]

As is apparent from the above description, according to the present invention, even when the operation for reducing the thermal power is performed rapidly, the gas supply amount can be reduced without forcibly temporarily stopping the operation mechanism during the operation. It is possible to prevent the misfire in the burner by decreasing the decreasing speed, and the size of the thermal power control device does not increase since the length of the throttle valve is required to be a minimum necessary.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a perspective view showing a shape of a spring.

FIG. 3 is a view showing an attached state of a spring.

FIG. 4 is a diagram for explaining the movement of a pin;

FIG. 5 is a view showing a second embodiment of a spring shape;

FIG. 6 is a view showing a third embodiment of a spring shape;

FIG. 7 is a perspective view of another type of thermal power control device to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal power control device 2 Lever 3 Opening window 4 Spring 5 Pipe 17 Throttle valve 18 Guide plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23N 5/26 F23N 1/00 102

Claims (2)

(57) [Claims] A pin protrudes from a throttle valve which is rotatable and movable forward and backward and adjusts a flow rate of gas by moving forward and backward, and moves the throttle valve in a low-fire direction at a predetermined position corresponding to the rotation position of the throttle valve. And a spring that biases the throttle valve in the direction of low heat by contacting the free end with the pin ,
The urging force of the spring causes the throttle valve to move quickly to the low heat direction.
When the throttle valve is rotated as much as possible, the pin separates from the cam surface.
The size is set to allow
When the throttle valve is turned away from the
The edge that comes into contact and moves the throttle valve in the direction of low heat
A thermal power control device for gas appliances characterized by being formed facing a surface . 2. The apparatus according to claim 1, wherein the spring is held on a cam plate having the cam surface formed thereon.