JPH0430964Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a rice cooker in which a lid body is provided with a steam vent body.

[Technical background of the invention] Conventionally, in this type of rice cooker, a lid body is provided with a steam venting body having a steam passage for discharging high temperature, high pressure steam inside the pot during rice cooking to the outside. In this case, a metal approximately disk-shaped valve body is installed at the top of the steam vent cylinder to open and close the steam passage, and this valve body always closes the steam passage due to its own weight, and when cooking rice, it is placed in the pot. It operates to open the steam passage by the steam pressure inside.

[Problems with the Background Art] However, in this conventional structure, the force of the valve body to close and open the steam passage depends on the weight of the valve body and the steam pressure in the pot, respectively. The drawback was that the opening and closing operation of the body became unstable, and the valve body vibrated up and down during rice cooking, producing a harsh noise.

[Purpose of the invention] The present invention was made in view of the above points.
The purpose is to stabilize the opening and closing operation of the valve body for opening and closing the steam passage for steam venting.
To provide a rice cooker that can prevent the generation of noise caused by vibration of a valve body during rice cooking, and has effects such as preventing the adverse effects of steam from affecting operating members.

[Summary of the invention] The invention provides a steam vent body having a steam passage provided in a lid body, and a valve body provided to open and close the steam passage, which is positioned so as to always close the steam passage. and an actuating member made of a shape memory alloy that is displaced when the temperature of the steam vent cylinder reaches a set temperature moves the valve body to a position that opens the steam passage in accordance with the displacement. The feature is that a partition wall body made of an elastic material is provided to isolate between the operating member and the steam passage, whereby the opening/closing operation of the valve body during rice cooking is controlled by the steam vent body. The operation is temperature-dependent, and the steam passing through the steam passage does not come into contact with the actuating member.

[Embodiment of the invention] A first embodiment of the invention will be described below with reference to FIGS. 1 to 3. In Fig. 2, 1 is the rice cooker main body, which consists of an outer case 2, an inner case 3, a heat insulator 4 placed between both cases 2 and 3, and a bottom part of the outer case 2. bottom case 5
It is composed of. Reference numeral 6 denotes a pot housed in the inner case 3, and an electric heater 7 for heating the pot 6 is disposed at the inner bottom of the inner case 3. Reference numeral 8 denotes a lid which is rotatably mounted on the top opening of the rice cooker body 1 to open and close it, and is composed of an outer lid 9 and an inner lid 10. Reference numeral 11 denotes a steam vent cylinder provided through the lid 8, and this will be described below with reference to FIG. 1 as well. That is, 12 is a lower cylindrical body inserted into a through hole 9a formed in the outer lid 9, and the upper end thereof is formed in a tapered shape that gradually widens upward. A mounting section 12a is formed at the upper part of the section, and is mounted on the upper opening periphery of the through-hole section 9a.
An engaging protrusion 12b that protrudes inward is formed in the intermediate portion of the tapered portion. Furthermore, the lower cylindrical body 12
A threaded portion 12c is formed in the intermediate portion,
A through hole 12d is formed at the lower end. This lower cylindrical body 12 is constructed by screwing a nut 13 into a threaded portion 12c and engaging an engagement recess 9c formed in an inner surface plate 9b of the outer lid 9. It is attached to the outer lid 9, and at this time, the lower end of the lower cylindrical body 12 projects into the pot 6 through a bush 10a fitted into the inner lid 10. Reference numeral 14 denotes an upper cylinder fitted to the upper end of the lower cylinder 12, the upper half of which is connected to a valve body 15 which will be described later.
The engagement protrusion 14a is formed at the lower end to accommodate the engagement protrusion 12b. A valve port 14b forming a part of the steam passage A is formed in the lower end of the upper cylinder 14. 16 is a cap having a plurality of steam exhaust holes 16a, and this cap has a cylindrical portion 1 on the top surface.
6b and a through hole 16d formed in the cylinder bottom 16c, and is attached to the upper end of the upper cylinder 14 so as to cover it. Now, the valve body 15 is made by fitting a substantially cylindrical elastic body tube part 18 made of silicone rubber, for example, to a substantially disc-shaped metal plate part 17 having good heat sensitivity, and integrally incorporating a large-diameter head part 19a. A pin 19 made of copper, for example, with good heat conduction efficiency is attached to the cylindrical portion 1.
The valve body 15 is inserted into a through hole 16d from above and connected to the metal plate portion 17 at its tip end, and the valve body 15 always closes the valve port 14b due to its own weight. Reference numeral 20 denotes an actuating member made of a shape memory alloy, such as an actuating coil spring, which is interposed in the cylindrical portion 16b of the cap 16, surrounding the pin 19, between the head 19a and the cylindrical bottom 16c. , the valve body 15 is always in a contracted state due to its own weight, but when the detected temperature reaches the set temperature (transformation point temperature of the shape memory alloy), the valve body 15 resists its own weight and is in an elongated state with a memorized shape. The displacement is set to operate.

Next, the operation of the above configuration will be explained. electric heater 7
When energized, the pot 6 containing rice and water is heated to start cooking rice. Eventually the temperature inside the pot 6 rises and steam is generated inside the pot 6, but at this time the valve port 1
4b is closed by the valve body 15, so the pot 6
The interior and the steam venting cylinder 11 are filled with steam, and the temperature of the steam venting cylinder 11 increases. When the temperature of the steam vent cylinder 11 reaches the set temperature, the actuating coil spring 20 made of a shape memory alloy expands and moves the valve body 15 upward against its own weight (Fig. 3). reference). As a result, the valve port 14b is opened, and the steam filling the steam exhaust cylinder 11 passes through the steam passage A and is discharged to the outside from the steam exhaust port 16a. In this case, the elastic cylinder portion 18 is connected to the cap 16.
By coming into close contact with the lower surface of the through hole 16d
It acts as a partition wall that prevents contact with the actuating coil spring 20 through the opening. after that,
When the rice cooking is finished, the temperature of the steam vent cylinder 11 decreases and becomes lower than the set temperature of the shape memory alloy, and the actuating coil spring 20 becomes unable to maintain the expanded state, and the valve body 15 becomes unstretched due to its own weight. is moved downward to contract the actuating coil spring 20 and close the valve port 14b.

According to this embodiment having such a configuration, the following effects can be obtained. That is, when cooking rice, the actuating coil spring 20 made of a shape memory alloy that senses temperature is expanded and pushes up the valve body 15 to open the valve port 14b, so that the opening and closing operation of the valve body 15 is stabilized. It is possible to prevent the valve body from producing rattling noise as in the past. Also, the valve body 15 is pushed up and the valve port 14
Since the elastic cylinder portion 18 acts as a partition wall separating the actuating coil spring 20 and the steam passage A when the actuating coil spring 20 is opened, steam is prevented from coming into contact with the actuating coil spring 20. The rust prevention ability of the actuating coil spring 20 is strengthened, and a good sanitary condition can be maintained. Furthermore, as mentioned above, after the rice cooking is finished, the valve body 15 closes the valve port 14b, so steam does not leak out to the outside, and the rice can be prevented from drying out during keeping warm.
Moreover, it is possible to improve the heat retention effect.

FIG. 4 shows a second embodiment of the present invention.
Hereinafter, the same parts as in the first embodiment will be given the same reference numerals, explanations will be omitted, and only different members will be described. Reference numeral 21 designates a cap that replaces the cap 16, and has a protrusion 21b protruding from its inner lower surface having a groove 21a in its center, and a cylinder having an engaging protrusion 21c around the protrusion 21b. A shaped protrusion 21d is provided in a protruding manner. Also,
A plurality of steam exhaust ports 21e are formed in the upper wall of the cap 21 around the protrusion 21d. 22 is a metal valve body with good heat sensitivity, which has a disk shape as a whole, and has a groove 2 in the center of the upper surface.
A protrusion 22b having a diameter 2a is provided in a protruding manner, and the outer peripheral end thereof is curved to form a groove 22c. Reference numeral 23 denotes a bellows-shaped cylindrical body made of an elastic material such as silicone rubber, which serves as a partition wall, and its upper and lower ends are respectively connected to the protrusion 21d of the cap 21 and the groove 22c of the valve body 22.
By fitting the cap 21 and the valve body 22
The valve port 14b is normally closed by its own spring force. 2
Reference numeral 4 designates an actuating member made of a shape memory alloy, such as an actuating coil spring, whose upper and lower ends are connected to the groove 21a of the cap 21 and the groove 22a of the valve body 22, respectively.
By engaging the cap 21 and the valve body 22
It is attached between the cylindrical body 23 and is always in an extended state due to the spring force of the cylindrical body 23, but when the temperature to be sensed reaches the set temperature (transformation point temperature of the shape memory alloy), the cylindrical body 23 It is set to be displaced into a contracted state, which is a memorized shape, against the spring force of.

In this second embodiment, the differences from the operation of the first embodiment will be described. That is, under normal conditions, the valve body 22 is moved downward by the spring force of the cylindrical body 23 to close the valve port 14b. When the temperature of the steam vent cylinder 11 reaches the set temperature, the actuating coil spring 24 made of shape memory alloy
is contracted and the valve body 22 resists the spring force of the cylindrical body 23.
move upward. Thereafter, when the temperature of the steam venting cylinder 11 decreases and becomes lower than the set temperature of the shape memory alloy, the actuating coil spring 24 can no longer maintain its contracted state, and the actuating coil spring 24 returns to its original state due to the spring force of the cylindrical body 23. returned to position. Further, since the actuating coil spring 24 is surrounded by the cylindrical body 23, the actuating coil spring 24 and the steam passage A are always reliably isolated, and the steam is effectively prevented from coming into contact with the actuating coil spring 24. Prevented.

In each of the above embodiments, the actuating coil springs 20 and 24 are used as the actuating members.
Instead, for example, a plate spring-like member may be used.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and it goes without saying that it can be implemented with appropriate modifications within the scope of the invention.

[Effects of the invention] As is clear from the above description, the present invention uses an operating member made of a shape memory alloy that detects the temperature of the steam exhaust cylinder to cause the valve body to open the steam passage included in the steam exhaust cylinder. In addition to providing a partition wall made of an elastic material to isolate the operating member from the steam passage, the opening and closing operations of the valve body can be stabilized and the valve body will not vibrate during cooking. It is possible to prevent the generation of noise caused by
This has excellent effects in that it is possible to prevent the adverse effects of steam on the operating member and to maintain a sanitary good condition.

[Brief explanation of the drawing]

Figures 1 to 3 show the first embodiment of the present invention, in which Figure 1 is an enlarged longitudinal sectional view of the main parts, Figure 2 is a partially cutaway side view of the entire rice cooker, and Figure 3 is a partially cutaway side view of the entire rice cooker. 4 is an enlarged vertical sectional view of the main part for explaining the operation, and FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention. In the drawing, 1 is the rice cooker main body, 8 is the lid body, 11 is the steam vent body, 15 is the valve body, 18 is the elastic cylinder part (partition wall body), and 20 is the actuating coil spring made of shape memory alloy (the actuating coil spring). 22 is a valve body, 23 is a cylindrical body (partition wall body), 24 is an actuating coil spring made of a shape memory alloy (actuating member), and A is a steam passage.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A lid pivotably installed on the top opening of the rice cooker body to open and close the rice cooker, a steam vent body provided on the lid body and having a steam passage, and this steam vent tube. a valve body provided in the body to open and close the steam passage and normally positioned to close the steam passage;
an actuating member made of a shape memory alloy that detects the temperature of the steam vent cylinder and displaces when the temperature reaches a set temperature to move the valve body to a position where the steam passage is opened; this actuating member and the steam A rice cooker comprising a partition wall made of an elastic material that separates the rice cooker from a passage. 2. Practical use characterized in that the partition wall body is composed of a cylindrical body arranged so as to surround the actuating member, and the actuating member is configured to be returned to its original position by the spring force of the cylindrical body. A rice cooker according to claim 1 of the invention registration claim.