JPH0233007Y2 - - Google Patents

Description

[Detailed description of the invention] <<Industrial application>> This invention is a dry cooking prevention device that automatically cuts off the gas supply when a dry cooking condition occurs during combustion in a gas combustor. Regarding.

《Prior art》 Conventionally, when a dry cooking condition occurs during gas combustion,
A known example of a device that automatically shuts off the gas supply is disclosed in Japanese Patent Publication No. 53-21526.

In this system, a safety valve (flow path cutoff valve) that is spring-biased in the valve-closing direction is arranged in the middle of the gas outlet path, a stepped portion is formed on the valve shaft of this safety valve, and a lock that can be engaged with this stepped portion is installed. The locking tool is biased toward the release side by a locking spring, the locking tool and a heat-sensitive device having a bimetal are connected by a wire cable, and a mechanism is formed on the heat-sensitive device to hold the locking tool in the locked position. When the lock detects the dry cooking condition and is activated, the mechanism that holds the locking tool in the locked position is released, the locking tool is moved in the unlocking direction, and the safety valve is closed.

<<Problems to be Solved>> In the conventional example described above, the locking tool is made to slide on the top surface of the valve box, and the engagement state holding tool of the locking tool is formed to be able to slide inside the casing of the thermal device. Therefore, it is necessary to perform high-precision surface processing on the contact surfaces between sliding members such as locking tools and locking tool engagement posture holding devices and supporting members such as valve boxes and cases, which makes manufacturing cumbersome. Moreover, the structure became more complicated, and there was a problem that the operating sensitivity during the valve closing operation was also reduced.

Further, the safety valve is configured to be reset by pressing the head of the valve stem. and,
Since this reset operation must be performed separately from the ignition operation, there is also the problem that the ignition operation is troublesome.

《Means for solving the problem》 The present invention is to form a device with a simple structure that can quickly cut off the gas supply when the cooking becomes dry. A flow path cutoff valve installed in the gas outlet path connecting to the gas burner is elastically biased in the closing direction by a valve closing spring, and the flow path cutoff valve is held in the open position by a leaf spring made of a shape memory alloy. The heat receiving part of the heat pipe is fixed to the upper wall of the casing of the gas combustor, and the heat pipe is configured to be able to heat a shape memory alloy plate spring, and the receiving flange protrudes from the valve stem. This creates a state in which the valve opening actuation piece of the flow path cutoff valve protrudes from the operating knob of the gasket, and when the shape memory alloy plate spring is below its transformation temperature, it enters the valve shaft lifting region and undergoes transformation. It is constructed of a shape-memory material that moves out of the valve shaft lifting area when the temperature exceeds the temperature, and is configured to be able to transmit the displacement of the valve opening actuating piece based on the ignition operation of the operating knob to the valve shaft via the receiving flange. When the valve stem is displaced in the valve opening direction, the shape memory alloy plate spring is engaged with the engagement part formed on the valve stem, and the flow path cutoff valve is held in the open state, and the casing is placed in the dry state. The feature is that when the amount of heat input at the heat receiving part of the heat pipe placed on the wall increases abnormally, the shape memory alloy leaf spring changes shape and switches the flow path cutoff valve to the closed state. .

<<Operation>> In the present invention, the valve stem of the flow path cutoff valve, which is spring-biased toward the valve closing side, is configured to be able to engage with a leaf spring made of a shape memory alloy, and the leaf spring made of a shape memory alloy is When the temperature is lower than the transformation temperature, it enters the valve shaft elevating region, and when it becomes higher than the transformation temperature, it moves out of the valve shaft elevating region. The structure is configured so that the heat pipe is heated by a fixed heat pipe, and a catch flange is provided protruding from the valve stem so as to protrude into the rotation area of the operating piece protruding from the operating knob. At the end of the ignition operation, the valve stem is pushed down against the valve closing spring to open the flow path cutoff valve. At this time, since the temperature of the shape memory alloy leaf spring is lower than the transformation temperature, it is in a state where it enters the valve shaft lifting area.
It engages with the engaging portion of the valve stem to hold the flow path cutoff valve in the open position.

When the rice cooks dry, the temperature of the container frame rises abnormally. The temperature is transmitted to the shape memory alloy leaf spring through a heat pipe to heat the shape memory alloy leaf spring. When the temperature of the shape memory alloy leaf spring reaches or exceeds the transformation temperature, the shape memory alloy changes its shape, exits the valve shaft lifting area and comes off the engagement part, and the flow path cutoff valve is closed by the valve closing spring. Ru.

《Example》 The drawings show an example of the present invention. Figure 1 is a vertical sectional view of the main part, Figure 2 is a perspective view of a gas stove with a built-in gas cylinder, and Figure 3 is a cross section taken along the line X-X in Figure 2. Figure, 4th
The figure is a view taken along the Y arrow in FIG.

In the figure, 1 is a casing, 2 is a combustion burner, 3 is a gas cylinder, 4 is a pressure regulator, 5 is a cylinder set lever for setting the gas cylinder 3, and 6 is an operating knob for igniting and adjusting the firepower.

The interior of the casing 1 is divided into a burner housing section 7 that houses the combustion burner 2, and an equipment room 8 that houses the gas cylinder 3, pressure regulator 4, and the like.

A gas tank 9 is connected to the pressure regulator 4, and a flow path cutoff valve 12 biased in the closing direction by a valve closing spring 11 is interposed in a gas outlet path 10 that communicates the gas tank 9 with the combustion burner 2. It has been done. The valve shaft 13 of the flow path cutoff valve 12 projects upward from the valve body 14, and has an engagement step 15 formed at the tip of the projection, and a flange 16 formed at the middle of the projection. This collar body 16 protrudes into the rotation locus of an actuating piece 17 protruding from the operating knob 6 of the gas cock 9 into the equipment room 8, and receives the actuating piece 17 at the end of rotation of the operating knob 6. When the valve is stopped, the valve shaft 13 is pushed down by the rotating force of the operating knob 6.

An elastic engagement member 18 is fixed to the upper surface of the valve body 14. This elastic engagement tool 18 consists of an L-shaped support fitting 19 and a shape memory alloy leaf spring 20, and the shape memory alloy leaf spring 20 is attached to the lifting region side of the valve shaft 13 while the shape memory alloy leaf spring 20 is lower than the transformation temperature. The shape of the valve shaft 13 is memorized so that it enters the temperature range and exits the vertical movement region of the valve shaft 13 when the temperature becomes higher than the transformation temperature. A heat pipe 21 is arranged between the support fitting 19 and the shape memory alloy leaf spring 20, and the heat receiving part 22 of this heat pipe 21 is connected to the casing 1 located between the burner housing part 7 and the equipment room 8. It is fixed to the inner surface of the upper wall 23 of.

Next, the operation of the flow path cutoff valve 12 configured as described above will be explained.

Before the ignition operation, as shown in FIG. 5A, the flow path cutoff valve 12 is closed by the spring force of the valve closing spring 11, and the shape memory alloy plate spring 20 is at a lower temperature than the transformation temperature. , the shape memory alloy plate spring 20 is in contact with the circumferential side of the valve stem because the flow path cutoff valve 12 is in the closed state.

When the operating knob 6 is rotated during ignition, at the end of the rotation, the operating piece 17 protruding from the operating knob 6 pushes the valve stem 13 through the catch collar 16, opening the flow path cutoff valve 12. . At this time, since the shape memory alloy plate spring 20 is still lower than its transformation temperature, the spring force causes the valve shaft to move as shown in FIG. 5B.
3 and engages with the engagement step 15 formed at the tip of the valve shaft, thereby holding the flow path cutoff valve 12 in an open state.

During combustion, the heat of the casing 1 is received by the heat receiving part 22 of the heat pipe 21, and the heat is transferred to the heat pipe 2.
2 to the shape memory alloy leaf spring 20. When the casing 1 becomes overheated as shown in FIG. 5C, the amount of heat input from the heat pipe 21 increases rapidly, and the shape memory alloy leaf spring 20 becomes hotter than its transformation temperature. ,
The shape changes and exits from the valve stem lifting area, and the flow path cutoff valve 12 is closed by the spring force of the valve closing spring 11.

In addition, the code|symbol 24 in the figure is a discharge terminal of a piezoelectric ignition device.

In the above embodiment, a gas stove with a built-in gas cylinder was described, but it can be used for city gas combustion appliances, LP gas combustion appliances, and combustion appliances other than stoves.

<<Effects>> The present invention is configured so that the valve stem of the flow path cutoff valve, which is spring-biased toward the valve closing side, and a shape memory alloy leaf spring can be engaged with each other, and the shape memory alloy leaf spring is heated at a temperature lower than the transformation temperature. The shape is memorized so that it enters the valve shaft elevating region on the side and retreats outside the valve shaft elevating region on the side higher than the transformation temperature, forming an engaging part on the valve shaft, and a heat receiving part on the upper wall of the casing. The shape memory alloy leaf spring is configured to be heated by a fixed heat pipe, so the shape memory alloy in the dry state changes shape and automatically closes the flow path cutoff valve to supply gas. can be stopped.

Moreover, the receiving collar protruding from the valve stem is formed so as to protrude into the rotation range of the valve opening actuation piece protruding from the operating knob, so that the flow path cutoff valve is automatically opened by igniting the operating knob. The valve can be opened automatically.

In addition, the opening operation of the flow path cutoff valve is performed by releasing the flow path cutoff valve from the open engagement state simply by changing the shape of the shape memory alloy, so the structure is simple and the accuracy of its operation can be improved.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of the main part, Figure 2 is a perspective view of a gas stove with a built-in gas cylinder, and Figure 3 is Figure 2
4 is a line sectional view, FIG. 4 is a view taken along the Y arrow in FIG. 1, and FIG. 5 is a schematic diagram showing an operating state. DESCRIPTION OF SYMBOLS 1...Casing, 2...Gas burner, 6...Operation knob, 9...Gas cock, 10...Gas outlet path, 11
...Valve closing spring, 12...Flow path cutoff valve, 13...12 valve shaft, 15...engaging portion, 16...receiving collar, 17...valve opening actuation piece, 20...shape memory alloy plate spring, 21...heat Pipe, 22...21 heat receiving part, 23...Casing upper wall.

Claims (1)

[Claims for Utility Model Registration] 1. A flow path cutoff valve 12 is disposed in a gas outlet path 10 that connects a gas stove 9 and a gas burner 2, and the flow path cutoff valve 12 is urged in the valve closing direction by a valve closing spring 11. At the same time, the flow path cutoff valve 12 is configured to be able to be held in the open position by a leaf spring 20 made of a shape memory alloy, and the heat receiving part 22 of the heat pipe 21 is fixed to the upper wall 23 of the casing of the gas combustor. , this heat pipe 21 connects the shape memory alloy leaf spring 20
The valve-opening piece 17 of the flow path cutoff valve 12 is configured to be heated, and the valve-opening piece 17 of the flow path cutoff valve 12 is provided so as to protrude from the operating knob 6 of the gas cooker 9. A protruding catch tsuba 16 is provided,
Valve opening actuation piece 1 based on the ignition operation of the operation knob 6
7 can be transmitted to the valve shaft 13 via the receiving collar 16, and a shape memory alloy plate spring 20 is formed on the valve shaft 13 by the displacement of the valve shaft 13 in the valve opening direction. When the flow path cutoff valve 12 is held in the open state by being locked to the casing 1, the amount of heat input at the heat receiving part 22 of the heat pipe 21 arranged on the upper wall of the casing 1 increases abnormally. A dry heating safety device for a gas combustor, characterized in that a shape memory alloy plate spring 20 changes shape and comes off from an engaging portion 15 to switch a flow path cutoff valve 12 to a closed state. 2. The dry cooking safety device for a gas combustor according to claim 1, wherein the gas combustor is a gas stove with a built-in gas cylinder.