rice cooker

Abstract

To provide a rice cooker that can reduce noise caused by relay sound of a relay switch installed inside the rice cooker.SOLUTION: A rice cooker according to the present invention comprises a plurality of heating means, a relay 45 for switching the heating means to be driven, a board body 42 on which the relay 45 is mounted, and a relay cap 46 covering the relay 45. Therefore, a portion of relay sound emitted from the relay 45 is blocked and absorbed by the relay cap 46, and the noise caused by the relay sound can be reduced.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rice cooker that includes a plurality of heating means and suppresses leakage of relay sound to the outside by switching means for switching the driven heating means.

Background Art

[0002] Conventionally, a rice cooker that includes a plurality of work coils as heating means and can select a driven work coil by a relay switch is known (for example, see Patent Document 1). The rice cooker described in Patent Document 1 includes, in addition to two sets of work coils, a first work coil C1 at the center of the bottom of the inner pot and a second work coil C2 at the corner between the outer peripheral side and the side of the bottom, and three sets of work coils including a third work coil C3 at the center of the side of the inner pot. The first work coil C1 and the second work coil C2 are connected in series with each other, and the third work coil C3 is connected in series with the first and second work coils C1 and C2.

[0003] Also, one end of the first work coil C1 is connected to a power line via a rectifying and smoothing circuit, and the other end of the third work coil C3 is connected to the collector side terminal of an IGBT (power transistor) and the trigger signal output terminal of a synchronization trigger circuit. A relay switch RS of a relay R is connected between the second work coil C2 and the third work coil C3, and by turning it OFF or ON, two types of work coil drive states, a drive state in which all of the first, second, and third work coils C1, C2, and C3 are driven and a drive state in which only the first and second work coils C1 and C2 on the bottom side are driven, are selectively controlled.

[0004] On the other hand, in the rice cooking process from the water absorption process to the heat preservation process or in each of these processes, by appropriately controlling the ON and OFF of the relay switch RS according to the rice cooking menu at that time and the amount of cooked rice, only the first and second work coils C1 and C2 or all of the first, second, and third work coils C1, C2, and C3 are driven and output controlled.

Prior Art Documents

[0005] [Patent Document 1] Patent No. 3228901 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] This type of relay switch RS produces a clicking sound when switching between ON and OFF. Therefore, if the relay switch RS switches ON and OFF frequently during the rice cooking process, the relay sound may be unpleasant. Also, if you set the rice cooker to cook rice in the morning, the cooking will take place during quiet times such as late at night or early in the morning, so the relay sound of the relay switch RS may disturb your sleep.

[0007] Therefore, the present invention aims to solve the above problems and provide a rice cooker that can suppress noise caused by the relay sound of a relay switch installed inside the rice cooker. [Means for solving the problem]

[0008] The rice cooker of the present invention allows the user to specify a cooking course including a scheduled cooking course, and comprises a plurality of heating means, a relay for switching which heating means is driven in the scheduled cooking course, a circuit board on which the relay is mounted, and a covering body covering the relay. A unit case housing the substrate and the covering, The covering has an opening, and when the covering covers the relay, the opening is closed by the substrate. When the covering body covers the relay, the covering body approaches or comes into contact with the unit case. It is characterized by the following. [Effects of the Invention]

[0009] According to the present invention, it is possible to suppress noise caused by the relay sound of the relay switch installed inside the rice cooker. [Brief explanation of the drawing]

[0010] [Figure 1] This is an upper perspective view of a rice cooker according to one embodiment of the present invention. [Figure 2] This is a longitudinal cross-sectional view of a rice cooker according to one embodiment of the present invention. [Figure 3] This is a perspective view of a substrate unit according to one embodiment of the present invention. [Figure 4] This is a rear view of the unit case of ADD. [Figure 5] This is a cross-sectional view along line AA in Figure 4. [Figure 6] Figure 4 is a cross-sectional view along line BB. [Figure 7] This is a front view of a relay cap attached to a relay in one embodiment of the present invention. [Modes for carrying out the invention]

[0011] The following describes preferred embodiments of the present invention, using a rice cooker as an example. The embodiments described below do not limit the scope of the present invention as described in the claims. Furthermore, not all of the configurations described below are essential requirements of the present invention.

[0012] Figures 1 to 7 show one embodiment of the rice cooker according to the present invention. First, the overall structure of the rice cooker will be explained based on Figures 1 and 2. 1 is the main body, which has a roughly rectangular shape with the front and rear, left and right sides facing each other when viewed from above, and the top surface is open. 2 is a lid that can be opened and closed to cover the top opening of the main body 1, and like the main body 1, it has a roughly rectangular shape with the front and rear, left and right sides facing each other when viewed from above, and the top surface is roughly flat. The main body 1 has a pot storage section 3 with an open top surface, and when the lid 2 is opened, a bottomed pot 4, which serves as a container for water and rice to be cooked, is detachably housed in the pot storage section 3. The pot storage section 3 is constructed by combining a bowl-shaped resin inner frame 5 and the like, and the whole is formed into a bottomed cylindrical shape.

[0013] The pot 4 is made primarily of aluminum 7, which has good thermal conductivity, and a heating element 8 made of a magnetic metal plate such as ferritic stainless steel is joined to the lower side and bottom of the outer surface of the main material 7. In addition, a heating coil 11 is provided on the outer surface of the inner frame 5, which faces the bottom surface of the pot 4 from the lower side surface, as a heating means for electromagnetic induction heating of the heating element 8 of the pot 4. When a high-frequency current is supplied to the heating coil 11, the alternating magnetic field generated from the heating coil 11 heats up the heating element 8 of the pot 4, thus heating the food being cooked in the pot 4 during cooking and warming. A pot sensor 12, which serves as a means for detecting the pot temperature, is positioned in the center of the bottom of the inner frame 5 so as to make elastic contact with the bottom surface of the outer surface of the pot 4.

[0014] A hinge portion 13 is provided at the rear of the lid 2, which serves as the connection point with the main body 1. A lid operating body 14 is also positioned on the front upper surface of the lid 2 in an exposed state. When this lid operating body 14 is pressed, the engagement between the main body 1 and the lid 2 is released, and the lid 2 opens around the hinge axis 13B of the hinge portion 13, which is pivoted by a hinge spring 13A located at the upper rear of the main body 1.

[0015] A steam vent 15 is provided on the rear upper surface of the lid 2 to discharge steam generated from the food being cooked in the pot 4 to the outside of the rice cooker. In addition to the steam vent 15 and the lid operating body 14, the top surface of the lid 2 is also equipped with an LCD (Liquid Crystal Display) 16 as a screen display unit and an LED (Light Emitting Diode) display unit 17 as a status display unit, and an operating means 19, which consists of a touch sensor and is positioned above the LCD 16, for starting cooking, selecting the time and cooking course, etc. Inside the lid 2 is a control PC (Printed Circuit) board 21 equipped with display and operation control means (not shown) for controlling the LCD 16, LED display unit 17, and operating means 19.

[0016] Below the lid body 2, an inner lid assembly 23 as a lower member of the lid body 2 is disposed. The inner lid assembly 23 is made of a metal material having a disk shape with substantially the same diameter as the upper opening of the pot 4, and includes an inner lid 24 that covers the upper opening of the pot 4, and a lid packing 25 as an elastic member provided on the entire outer circumference of the inner lid 24 to seal the space between the inner lid 24 and the pot 4, and a pressure regulating portion 26 that adjusts the internal pressure of the pot 4. The annularly formed lid packing 25 abuts against the upper surface of the pot 4 when the lid is closed as shown in FIG. 2, closes the gap between the pot 4 and the inner lid 24, and seals the steam generated from the pot 4.

[0017] Inside the lid body 2, a lid heater 31 as a lid heating means for heating the inner lid 24 and a thermistor-type lid temperature sensor 32 for controlling the temperature of the inner lid 24 by the lid heater 31 are provided respectively. And inside the lid body 2, a steam discharge path 33 that connects the steam port 15 and the pressure regulating portion 26 is formed as a path for discharging the steam generated in the pot 4 to the outside.

[0018] A pressure regulating valve 34 for opening and closing the steam discharge path 33 between the inside of the pot 4 and the steam port 15 is provided in the pressure regulating portion 26. The pressure regulating valve 34 is in a ball shape and is interlocked with a solenoid 35 provided inside the lid body 2. When discharging the steam in the pot 4 to the outside, the steam discharge path 33 is opened, and when pressurizing or depressurizing the inside of the pot 4, the solenoid 35 rolls the pressure regulating valve 34 so as to block the steam discharge path 33. And during pressurization, when the cooked rice in the pot 4 is heated by high-frequency energization to the heating coil 11, the cooked rice boils and steam is generated, and when the internal pressure of the pot 4 reaches a predetermined value as this steam fills the pot 4, the steam discharge path 33 is opened against the self-weight of the pressure regulating valve 34, so that the pressure inside the pot 4 is maintained above atmospheric pressure. Also, a pressure sensor (not shown) is provided inside the lid body 2 facing the pressure regulating portion 26 to detect the pressure inside the pot 4.

[0019] 38 is a decompression means for making the inside of the pot 4 lower than the normal atmospheric pressure when the lid body 2 is closed on the main body 1. The decompression means 38 accommodates the pot 4 in the pot housing 3, and after closing the lid body 2, energizes the solenoid 35 to lower the internal pressure of the sealed pot 4 with the pressure regulating valve 34 blocking the steam discharge path 33.

[0020] On the inner rear side of the main body 1, a unitized substrate unit 41 including heating control means for controlling the heating coil 11, the lid heater 31, etc. is disposed. As shown in FIG. 3, the substrate unit 41 is mainly composed of a substrate body 42, a heat sink 43 mounted on the substrate body 42, and various electronic components 44. The various electronic components 4 are included a relay 45 which is an on / off switch for the heating coil 11 and the lid heater 31. A relay cap 46 which is a covering body is detachably attached to the relay 45. The substrate unit 41 is housed in a unit case 47 (see FIGS. 4 to 6) for electrically insulating and protecting the substrate unit 41.

[0021] Mainly as shown in FIGS. 3 and 5 to 7, the relay cap 46 as a covering body has an opening 51 on the front side, and has a rear wall portion 52, an upper wall portion 53, a lower wall portion 54, a front left wall portion 55, a rear left wall portion 56, and a right wall portion 57. The relay cap 46 is integrally formed of a silicon material with the rear wall portion 52, the upper wall portion 53, the lower wall portion 54, the front left wall portion 55, the rear left wall portion 56, and the right wall portion 57. The rear wall portion 52, the front left wall portion 55, the rear left wall portion 56, and the right wall portion 57 are formed in a substantially rectangular shape. The upper wall portion and the lower wall portion 54 have the same shape and are formed in a substantially pentagonal shape. The connecting portions between the rear wall portion 52, the upper wall portion 53, the lower wall portion 54, the front left wall portion 55, the rear left wall portion 56, and the right wall portion 57 are formed in an arc shape. Since the relay sound emitted from the relay 45 is the largest on the rear wall portion 52 side, the wall thickness of the relay cap 46 is formed thickest on the rear wall portion 52.

[0022] The outer casing 48 of the relay 45 is rectangular in shape, and the inside of the relay cap 46 has four inner corners 58A, 58B, 58C, and 58D that abut against the four side corners 48A, 48B, 48C, and 48D of the outer casing 48, an upper inner surface 59 which is the thinner part of the upper wall 53, a lower inner surface 60 which is the thinner part of the lower wall 54, a left inner surface 61 which is the thinner part of the front left wall 55 and the rear left wall 56, and a right inner surface 62 which is the thinner part of the right wall 57.

[0023] The interior corner 58A has a left upper interior surface 63 which is part of the upper wall 53, and an upper left interior surface 64 which is part of the front left wall 55 and the rear left wall 56, with the left upper interior surface 63 and the upper left interior surface 64 forming a right angle. The interior corner 58B has a right upper interior surface 65 which is part of the upper wall 53, and an upper right interior surface 66 which is part of the right wall 57, with the right upper interior surface 65 and the upper right interior surface 66 forming a right angle. The interior corner 58C has a left lower interior surface 67 which is part of the lower wall 54, and a lower left interior surface 68 which is part of the front left wall 55 and the rear left wall 56, with the left lower interior surface 67 and the lower left interior surface 68 forming a right angle. The inner corner portion 58D has a right lower inner surface portion 69 which is part of the lower wall portion 54 and a lower right inner surface portion 70 which is part of the right wall portion 57, and the right lower inner surface portion 69 and the lower right inner surface portion 70 are at a right angle.

[0024] Here, we will explain how to attach and detach the relay cap 46. With the four inner corners 58A, 58B, 58C, and 58D of the relay cap 46 in contact with the four side corners 48A, 48B, 48C, and 48D of the outer casing 48 of the relay 45, the relay cap 46 is pushed in, and the front end face 71 of the relay cap 46 comes into contact with the main board 42. The relay 45's outer casing 48 is then press-fitted into the relay cap 46, completing the installation of the relay cap 46. With the relay cap 46 installed, the opening 51 is closed by the main board 42, and the relay 45 is completely covered by the main board 42 and the relay cap 46. Normally, once the relay cap 46 is installed, it does not need to be removed as it is incorporated into the rice cooker product, but since it is only press-fitted, it can be easily removed by pulling it out.

[0025] As shown in Figures 5 and 6, when the relay cap 46 is attached to the relay 45, a space T1 is formed between the outer casing 48 and the rear wall portion 53 of the relay 45. In addition, a space T2 is formed between the outer casing 48 and the upper inner surface portion 59, a space T3 is formed between the outer casing 48 and the lower inner surface portion 60, a space T4 is formed between the outer casing 48 and the left inner surface portion 61, and a space T5 is formed between the outer casing 48 and the right inner surface portion 62. Of spaces T1 to T5, the distance between the relay cap 46 and the outer casing 48 is longest in space T1.

[0026] As shown in Figures 4 to 6, the unit case 47 that houses the substrate unit 41 has a front case 76 and a rear case 77, and a housing space S is formed inside by attaching the front case 76 and the rear case 77 to each other. The substrate unit 41 is placed in the front case 76, and the rear case 77 covers the substrate unit 41.

[0027] As shown in Figure 6, with the relay cap 46 attached to the relay 45, the front left wall portion 55 is located near the edge portion 42A of the substrate body 42. When the rear case 77 is attached to the front case 76, the rear left wall portion 55 is positioned close to the arc-shaped portion 78 of the rear case 77. Therefore, even if the relay cap 46 moves in a direction that causes it to detach from the relay 45 due to vibrations or shocks applied to the rice cooker, for example, the rear left wall portion 55 will come into contact with the rear case 77, preventing it from moving beyond a predetermined amount (the distance L between the rear left wall portion 55 and the rear case 77). In this embodiment, a gap is formed between the rear left wall portion 55 and the rear case 77 (arc-shaped portion 78), but it is also possible to have the relay cap 46 and the rear case 77 come into contact with each other when the rear case 77 is attached to the front case 76, so that the relay cap 46 does not move in a direction that causes it to detach.

[0028] As described above, the rice cooker of this embodiment includes a heating coil 11 and a lid heater 31, which are multiple heating means, a relay 45 that switches which heating means to drive, a circuit board body 42 on which the relay 45 is mounted, and a relay cap 46 that covers the relay 45. Therefore, a portion of the relay sound emitted from the relay 45 is blocked and absorbed by the relay cap 46, thereby suppressing noise caused by the relay sound.

[0029] Furthermore, in this rice cooker embodiment, the relay cap 46 has an opening 51, and the opening 51 is closed by the circuit board body 42 when the relay cap 46 covers the relay 45. Therefore, the emission of relay noise from the relay 45 through the opening 51 can be suppressed.

[0030] Furthermore, in this rice cooker, the relay cap 46 is held in place by the inner corners 58A, 58B, 58C, and 58D of the relay 45 by contacting the side corners 48A, 48B, 48C, and 48D of the relay 45, thereby preventing the relay cap 46 from coming off unintentionally.

[0031] Furthermore, in this embodiment of the rice cooker, with the relay cap 46 covering the relay 45, the relay cap 46 has an upper wall portion 53, a lower wall portion 54, a front left wall portion 55, and a right wall portion 57 that are perpendicular to the main board body 42. Spaces T2, T3, T4, and T5 are formed between the relay 45 and the upper wall portion 53, lower wall portion 54, front left wall portion 55, and right wall portion 57. As a result, the relay sound generated from the relay 45 moves within spaces T2, T3, T4, and T5, and a portion of it is reflected by the upper wall portion 53, lower wall portion 54, front left wall portion 55, and right wall portion 57, and moves again within spaces T2, T3, T4, and T5, repeating this process. This reduces the energy of the relay sound, making it quieter and lower in pitch. Specifically, compared to the case where the relay 45 and relay cap 46 are in close contact without a space T1 to T5 between them, the sound quality of the relay noise can be changed from high to low frequencies, making it less likely for the user to perceive the relay noise.

[0032] Furthermore, in this embodiment of the rice cooker, with the relay cap 46 covering the relay 45, the relay cap 46 has a rear wall portion 52 that is parallel to the main board body 42, and a space T1 is formed between the relay 45 and the rear wall portion 52. As a result, the relay sound generated from the relay moves within the space T1, a portion of which is reflected by the rear wall portion 52, and moves again within the space T1, repeating this process. This reduces the energy of the relay sound, making the relay sound quieter and lower in pitch.

[0033] Furthermore, in this rice cooker, since the relay cap 46 is made of silicone material, the relay 45 can be easily press-fitted, making installation very easy. In addition, it is possible to block and absorb some of the relay noise, thereby suppressing noise caused by the relay.

[0034] It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. For example, the relay cap 46 may have a different external shape as long as it can exhibit sound insulation, sound absorption, and low-frequency effects on relay noise. Also, in the above embodiments, the front end face portion 71 abuts against the substrate body 42 and the opening 51 is closed by the substrate body 42, but if the relay 45 is covered to a certain extent by the relay cap 46, the front end face portion 71 does not have to abut against the substrate body 42 and the opening 51 does not have to be closed by the substrate body 42. [Explanation of Symbols]

[0035] 11. Heating coil (heating means) 31. Lid heater (heating means) 42 Main circuit board (circuit board) 45 Relay 46 Relay cap (insulation) 47 Unit Case vinegar 51 Opening 52 Rear wall (second wall) 53 Upper wall (first wall) 54 Lower wall part (first wall part) 55. Front left wall (first wall) 57 Right wall section (first wall section) T1 Space T2 Space T3 Space T4 Space T5 Space

Claims

1. It is possible to select a rice cooking course that includes delayed cooking, Multiple heating means, A relay that switches the heating means to be driven in the rice cooking course of the reserved rice cooking, A circuit board on which the relay is mounted, A covering body that covers the relay, The unit comprises the substrate and the covering body, The covering has an opening, With the covering body covering the relay, the opening is closed by the substrate. A rice cooker characterized in that the covering body covers the relay and the covering body is in close proximity to or in contact with the unit case.

2. With the covering body covering the relay, the covering body has a first wall portion that is perpendicular to the substrate, The rice cooker according to claim 1, characterized in that a space is formed between the relay and the first wall portion.

3. The covering has a second wall portion that faces the substrate when the relay is covered, The rice cooker according to claim 1, characterized in that the second wall portion is formed to be the thickest.

4. With the covering body covering the relay, the covering body has a second wall portion that is parallel to the substrate, The rice cooker according to claim 1, characterized in that a space is formed between the relay and the second wall portion.

Images