JPS591616Y2 - Heating vessel pressure valve device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a pressure valve device for a heating container, such as a pressure cooker or a rice cooker, which is heated in a closed state.

This type of valve device has been used in various ways as pressure regulating valves and safety valves, but in those, the valve body only responds to pressure by its own weight or spring biasing force. The object of the present invention is to provide a pressure valve device for a heating container in which the operation of these valves is controlled even in response to a specific temperature, and which can exhibit more desirable pressure regulation and safety functions.

To explain the embodiment shown in FIGS. 1 to 3, 1 is a pressure cooker main body, and a lid 2 that seals the pressure cooker body,
A pressure regulating valve 3 and a safety valve 4 are provided.

5 is a lid tightening bundle, 6 is a support thereof, 7 is a support retaining piece of the main body 1, and 8 is a handle of the main body 1.

The safety valve 4 includes a valve body 14 in a communication passage 4a that communicates the inside and outside of the main body 1 with a valve body 14 that is biased by a normal coil spring 9 made of spring steel and always closes the communication passage 4a.
It has a normal structure in which the communication passage 4a is opened when the inside reaches an abnormal pressure.

On the other hand, the pressure regulating valve 3 is provided with a valve body 11 in a communication passage 3a that communicates the inside and outside of the main body 1, and is biased by a shape memory alloy coil spring 10 to close the communication passage 3a. Natural length l shown by the dashed line in Figure 3 at room temperature
.

It is said to have a shape memory with a natural length of 11 shown by the two-dot chain line at a certain temperature just before the end of rice cooking, and when it is compressed to a length of 12, the valve body 1
It is acting on 1.

The relationship l between the lengths of this spring 10.

> l 1 > l 2 so that the spring 10 has a natural length l until said constant temperature is reached.

is compressed to 12, and the valve body 11 does not open by applying a large biasing force to the valve body 11 and the pressure inside the main body 1 continues to increase. When the above-mentioned constant temperature is reached, the state changes due to the shape memory property and the valve body 11 does not open. The length becomes short to 11, and the compression ratio becomes small up to length 12.The biasing force on the valve body 11 is reduced, and when the pressure exceeds a certain pressure, the valve body 11 is opened to discharge steam,
Cook the rice while adjusting the pressure and moisture.

Moreover, after cooking rice, the spring 10 returns to its natural length l as the temperature drops below the above-mentioned constant temperature.

The state returns to the above state, and the valve 11 is strongly closed to ensure heat retention and prevention of excessive steam outflow, thereby preserving the deliciousness of the rice for a longer time than before.

Furthermore, the rice cooking time is shortened by increasing the pressure just before the end of the rice cooking, which is a distant relative of energy saving.

The communication passage 3a is formed by a steam cylinder 3b with a top plate whose lower end is fixed onto the lid 2 with a rivet 13, and a communication hole 3d is formed between the lid 2 and the top plate 3C, and the valve body 11 is connected to the lid 2. The communication hole 3d opened in the hole 3d is crimped and closed from above.

When the steam is released, the crimp closure is forced open and the steam is forced to flow out, so the steam that flows out is subjected to a strong tightening action.
The vapor and the vapor are sufficiently separated from each other, and the liquid components of the vapor are prevented from blowing out to the outside.

Of course, for this airtight separation, it is possible to adopt the right type mechanism already known from pressure regulating valves for rice cookers.

The valve body 11 is attached to the cylinder 3b in order to stably move up and down within the cylinder 3b.
The outer diameter is close to the inner diameter b, and a cutout 11a is formed on the outer periphery so as not to obstruct the outflow of steam, as shown in FIG. 2, but it can be freely designed depending on the form of the communicating path 3a, etc.

FIG. 4 shows an improved example of the safety valve 4 shown in FIG. 1, in which a coil spring 15 made of a shape memory alloy acts on the valve body 14 that opens and closes the communication passage 4a. 14
and the top plate 4C of the passage tube 4b,
At room temperature, the valve body 14 is moved from the top plate 4C to S.

When the valve body 14 is protruded and positioned below the valve seat 4d (dotted chain line) and reaches a certain heat treatment temperature (approximately 130°C for rice cooking), the state change due to the shape memory property causes the valve body 14 to move to the valve seat 4.
It is positioned at a protruding distance S2 from the top plate 4C located above d (double-dashed line).

As a result, the valve body 14 is normally S.

The protruding distance S to be crimped and closed to the valve seat 4d where it should be located.
1 (solid line), the spring 15 is compressed, and is biased to the closed state by the amount of compression, and will not open unless a certain set abnormal pressure is reached.

When the above-mentioned foot heat treatment temperature is reached, the spring 15 undergoes the state change and contracts, forcibly separating the valve body 14 from the valve seat 4d as shown by the two-dot chain line in FIG. 4, and opening the communication passage 4a.

The state changing force due to the shape memory property of the spring 15 is relatively strong, and even when the inside is clogged with a small amount of cooking waste and pressure is not enough to operate, it can operate reliably in addition to responding to temperature.

FIG. 5 shows a plate spring 16 made of a shape memory alloy in place of the coil spring 10 in FIG. It exhibits a strong closing force when it is in the posture, and at a certain temperature just before the end of cooking, the state changes due to its shape memory property, and it becomes the posture shown by the two-dot chain line, weakening the closing force.

The other structures and operations are the same as those in FIG. 3, and their explanations will be omitted.

According to this invention, in a pressure valve device for a container that involves heating, the spring that biases the valve body to keep it closed at all times is made of a shape memory alloy, and the state change due to the shape memory property in response to the desired temperature allows it to be used as before. By changing or increasing/decreasing the response characteristics of the valve to pressure, it is possible to respond to temperature changes during heat treatment such as cooking, thereby achieving more desirable pressure regulation conditions and more reliable operating conditions, and improving heat treatment effects. You can measure improvement and safety.

Moreover, the structure is not complicated at all compared to the conventional one, and there is an advantage that a high-performance valve can be provided at a low cost.

[Brief explanation of drawings]

Fig. 1 is a front view of a pressure cooker equipped with a pressure valve according to an embodiment, with a half section cut away, Fig. 2 is an oblique view of the valve body, and Fig. 3 is a sectional view of the pressure regulating valve. , FIG. 4 is a sectional view of a safety valve as another embodiment, and FIG. 5 is a sectional view of a part of a pressure regulating valve as a modified example. 1...Pressure cooker body (heating container), 2...
・Lid, 3...pressure regulating valve, 4...safety valve,
3 a, 4 a...Communication path, 10j5゜16
...Shape memory alloy spring, 11.14...
... Valve body, 16a... Valve body dual-purpose part.

Claims (7)

[Scope of utility model registration request] (1) Equipped with a communication path that communicates the inside and outside of the heating container, and a valve body that opens and closes the communication path depending on the internal pressure of the heating container, and the valve body is biased in the closing direction by a shape memory alloy spring. ,
A pressure valve device for a heating container, characterized in that the bias against the valve body is at least weakened by a state change due to a shape memory characteristic of the spring at a specific temperature. (2) The spring strongly biases the valve body to keep it closed until a certain temperature, increases the pressure inside the heating container, and when the certain temperature is reached, the spring attaches to the valve body due to a state change due to its shape memory property. A pressure valve device for a heating container according to claim 1, which performs a pressure regulating function by weakening the force and opening the valve body when the internal pressure of the heating container is equal to or higher than a set pressure. (3) The spring biases the valve body to close up to a certain temperature, and opens the valve body only when the pressure is higher than the set pressure. A pressure valve device for a heating container according to claim 1, which has a safety function for the heating container by being opened in the following manner. (4) The pressure valve device for a heating container according to claim 1, wherein the heating container is a pressure cooker. (5) The pressure valve device for a heating container according to claim 1, wherein the heating container is a rice cooker. (6) The pressure valve device for a heating container according to any one of claims 1 to 5, wherein the spring is formed as a coil spring. (7) A pressure valve device for a heating container according to any one of claims 1 to 5, which is provided on the lid of the heating container.