Heating cooker

Abstract

A heating cooker for vertically sandwiching and heating an object to be heated comprises: a base (10); a cover (30); a lower plate assembly (50L); an upper plate assembly (50U); and at least one of a lower spring (61) and an upper spring (63). The cover (30) is rotatably attached to the back surface-side of the base (10) via a hinge part (80) so as to have the upper part of the base (10) openable in accordance with rotation. The lower plate assembly (50L) is held by the base (10) and has a film heater integrally built in the lower plate assembly, and a plate (51) is in contact with the lower surface of the object to be heated. The upper plate assembly (50U) is held by the cover (30) and has a film heater integrally built in the upper plate assembly. When the cover (30) is closed, the plate (51) comes into contact with the upper surface of the object to be heated. The lower spring (61) biases the lower plate assembly (50L) upward. The upper spring (63) biases the upper plate assembly (50U) downward.

Description

heating cooker

[0001] The present disclosure relates to a cooking appliance.

[0002] Conventionally, cooking appliances for heating objects such as bread are known. For example, a cooking appliance described in Patent Document 1 has a heating chamber formed inside, surrounded by a bottom plate provided on the top surface of the cooking appliance body and a recess in the lid. The bottom surface of the bread contacts the bottom plate, but the top surface of the bread does not contact the heating chamber top plate. The bread is heated from below by heat conduction from the bottom plate and from above by radiant heat from the heating chamber top plate.

[0003] When the lid is closed, the sealing member tightly contacts the periphery of the bottom plate, forming a tightly sealed heating chamber. Moisture released from the bread during cooking is trapped in the tightly sealed heating chamber.

[0004] Japanese Patent Application Laid-Open No. 2019-7634

[0005] In the conventional technology of Patent Document 1, the volume of the heating chamber is several times larger than the volume of the bread, so a large amount of moisture is released from the bread, causing the bread to lose its moist texture. This tendency becomes more pronounced the thinner the bread. In addition, because the top surface of the bread does not come into contact with the heating chamber top plate, it is difficult to adjust the baking level appropriately, making it difficult to achieve a crispy surface.

[0006] An object of the present disclosure is to provide a cooking device that can maintain moisture inside an object to be heated and can properly cook the surface.

[0007] The cooking device according to the present disclosure is a cooking device that heats an object to be heated by sandwiching it between the top and bottom, and includes a base, a cover, a lower plate assembly, an upper plate assembly, and at least one of a lower spring or an upper spring.

[0008] The cover is rotatably attached to the rear side of the base via a hinge, and can open and close the top of the base in response to the rotation.

[0009] The lower plate assembly is held by the base, has a film heater built in, and the plate abuts the lower surface of the object to be heated. The upper plate assembly is held by the cover, has a film heater built in, and when the cover is closed, the plate abuts the upper surface of the object to be heated.

[0010] The lower spring biases the lower plate assembly upward. The upper spring biases the upper plate assembly downward. Preferably, the cooking appliance includes both a lower spring and an upper spring, and the spring load of the lower spring is set to be greater than the spring load of the upper spring.

[0011] In the cooking device of the present disclosure, plates of a plate assembly with a built-in film heater contact both the top and bottom surfaces of an object to be heated and heat it by thermal conduction. Furthermore, when the object to be heated is bread, an excessively large space is not formed around the bread, minimizing the amount of moisture that is expelled. This allows the surface of the bread to be toasted appropriately while maintaining the moisture inside, resulting in a favorable texture that combines a moist interior with a crispy surface.

[0012] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a perspective view of a cooking device according to an embodiment with the cover closed, Fig. 2 is a perspective view of a cooking device according to an embodiment with the cover open, Fig. 3 is a plan view of the cooking device according to the embodiment, Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 3, Fig. 5 is a plan view of the cooking device with the cover open and the lower plate removed, Fig. 6 is a plan view of the heater-integrated plate, Fig. 7 is a diagram illustrating the action of a spring load on an object to be heated (bread), Fig. 8 is an enlarged cross-sectional view illustrating a locking mechanism and an unlocking mechanism between the cover and the base, Fig. 9 is an enlarged cross-sectional view taken along line IX-IX of Fig. 5 showing a torque hinge of the hinge portion, and Fig. 10 is an enlarged cross-sectional view taken along line X-X of Fig. 5 showing a return spring of the hinge portion.

[0013] (One embodiment) A cooking device according to one embodiment will be described with reference to the drawings. The cooking device of this embodiment is a cooking device that heats an object to be heated, such as bread, by sandwiching it between upper and lower plates, and is also called a "toaster" when used to heat bread in particular. In this embodiment, the object to be heated will be described as bread. As an object to be heated other than bread, foods with a relatively large contact area with the plates, such as pizza, rice cakes, sandwich-type foods, etc., are suitable.

[0014] Fig. 1 shows the overall configuration of the cooking appliance 100 with the cover closed, and Fig. 2 shows the overall configuration of the cooking appliance 100 with the cover open. The cooking appliance 100 is mainly composed of a base 10, a bottom case 20, and a cover 30, which are molded resin parts. Hereinafter, the lower left side of Fig. 1 and Fig. 2 will be referred to as the front, and the upper right side as the rear. The power cord connected to the rear of the bottom case 20 is not shown.

[0015] The portion of the base 10 that is not covered by the cover 30 is referred to as the front panel portion 11, and the portion behind the front panel portion 11 that is covered by the cover 30 is referred to as the cover portion 12. The front panel portion 11 is provided with a dial 70 that allows the user to change the heating conditions. The cover portion 12 houses a lower plate assembly 50L that has a film heater (described later) built in integrally therewith.

[0016] The bottom case 20 provided on the bottom side of the base 10 has four legs. Three of the legs 21, excluding the leg 22 directly below the dial 70, are molded from resin and are integral with the bottom case 20. The leg 22 directly below the dial 70 is formed from a separate metal part that also serves as an assembly point for the dial 70. A heat exhaust port (not shown) is provided on the bottom surface of the bottom case 20 to exhaust heat accumulated inside to the outside. The heights of the legs 21 and 22 are set so that a space for air to circulate is secured between the bottom surface of the bottom case 20 and the floor.

[0017] The cover 30 is rotatably attached to the rear side of the base 10 via a hinge 80, and can open and close the upper part of the base 10 in response to the rotation. The hinge 80 is supported by the support cylinder 18 of the base 10. A lever 40 that allows the user to open and close the cover 30 is provided at the boundary between the top wall 311 and the front wall 312 of the cover 30.

[0018] An upper plate assembly 50U, which has a film heater (described later) built into it, is housed facing downward inside the cover 30. When the cover 30 is closed, a loaf of bread, which is an object to be heated, is sandwiched between the plate 51 of the lower plate assembly 50L and the plate 51 of the upper plate assembly 50U and heated.

[0019] Upper plate holding mechanisms 37 including holding protrusions 371 and release operation portions 372 are provided on the front and rear of the upper plate assembly 50U. The function of the upper plate holding mechanisms 37 will be described later. A claw 44 (see FIG. 8) of a locking mechanism, which will be described later, appears on the front side of the front upper plate holding mechanism 37.

[0020] As shown in FIG. 3 , the dial 70 can switch the heating temperature and heating time conditions between three modes, for example, LO, MID, and HI. In LO mode, the heating temperature is set low, emphasizing a moist texture by maintaining the moisture inside the bread. In MID mode, heating is possible in a short time, which is suitable for breakfast when time is short. In HI mode, baking is done at a higher temperature for a long time, emphasizing a crispy texture on the surface, and is also suitable for heating and cooking frozen bread. When the user turns the dial 70 from OFF to one of the modes, preheating begins, and when preheating is complete, the button labeled "PUSU START" lights up. When the user presses the button after it lights up, heating begins under the heating conditions of the selected mode.

[0021] Next, with reference to Figures 4 to 10, the internal structure of the cooking appliance 100 will be described, particularly the structure for holding the lower plate assembly 50L and the upper plate assembly 50U and the structure for bringing the plate 51 into contact with the bread to be heated with an appropriate load. As shown in Figure 4, when the cover 30 is closed, the connecting portion 55 of the lower plate assembly 50L is held by the lower plate holder 15 of the base 10, and the connecting portion 55 of the upper plate assembly 50U is held by the upper plate holder 35 of the cover 30. Furthermore, when the cover 30 is open, the lower plate assembly 50L is removable from the base 10, and the upper plate assembly 50U is removable from the cover 30. This allows for easier cleaning.

[0022] In this embodiment, the lower plate assembly 50L and the upper plate assembly 50U are configured with the same shape and characteristics, and can be swapped by the user when reinstalling. In other words, one type of plate assembly is commonly used as the "lower plate assembly 50L and upper plate assembly 50U." For convenience of explanation, the reference numeral "50L" will be used when used as the lower plate assembly, and the reference numeral "50U" will be used when used as the upper plate assembly. Items common to both uses will be referred to as the "plate assemblies 50L, 50U."

[0023] 5 shows a plan view of the base 10 with the lower plate assembly 50L removed. The cover 12 has a storage chamber 125 formed inside an edge 124, and a cylindrical lower plate holder 15 is provided in the center of the storage chamber 125. Relief recesses 17 are formed in two locations, one at the front and one at the rear of the edge 124. In other embodiments, the vapor deposition film VD, which will be described later, may not be formed.

[0024] A center hole 15c and multiple terminal holes 15t are formed in an insulator receiving portion 155 provided at the center of the lower plate holder 15. An annular groove 156 is formed radially outward from the receiving portion 155. A plurality of rubber pads 157 (eight in this embodiment) are arranged circumferentially radially outward from the annular groove 156, with grooves 158 sandwiched between them. As indicated by dashed lines, lower springs 61 are installed directly below four of the eight pads 157. The lower springs 61 urge the back cover 54 of the lower plate assembly 50L, which is in contact with the pads 157, upward.

[0025] 6 shows a separate diagram of the lower plate assembly 50L and upper plate assembly 50U. The lower plate assembly 50L is held by the base 10, with the plate 51 abutting against the underside of the bread. The upper plate assembly 50U is held by the cover 30, with the plate 51 abutting against the top surface of the bread when the cover 30 is closed.

[0026] The plate assemblies 50L and 50U have a film heater 53 built into the plate 51 along the heat transfer surface 52 (see FIG. 7). The film heater 53 is configured so that a thin film conductor forms a zigzag conductive path within a substantially rectangular space. The film heater 53 can heat the heated object uniformly across the entire heat transfer surface 52, eliminating unevenness in cooking depending on the position.

[0027] Power is supplied to both ends of the conductive path of the film heater 53. The temperature of the film heater 53 is detected by a temperature sensor such as a thermistor (not shown). Alternatively, a sensorless method may be employed in which the temperature is estimated by calculating the resistance from the current value based on the resistance-temperature characteristics of the film heater 53. The sensorless method can reduce the influence of variations in the detected temperature due to the installation position of the temperature sensor.

[0028] As shown in Figures 4 and 7, the back side of the plate 51 is covered with a back cover 54, which has a cylindrical, insulating connection portion 55 located in its center (see the dashed line in Figure 6). An annular rib 56 is formed on the outer edge of the connection portion 55. A center pin 55c and multiple terminals 55t are inserted into the inside of the annular rib 56. The annular rib 56 fits into an annular groove 156 in the base 10, and the center pin 55c and multiple terminals 55t fit into the center hole 15c and multiple terminal holes 15t, respectively.

[0029] In the illustrated example, the multiple terminals 55t include four terminals: two power terminals for supplying power to the film heater 53 and two sensor terminals for detecting the temperature of the film heater 53. If a sensorless system is adopted, the sensor terminals are not necessary. The terminal holes 15t into which the terminals 55t are fitted are electrically connected to a control circuit (not shown) provided inside the bottom case 20.

[0030] The configuration on the cover 30 side when the upper plate assembly 50U is removed is basically the same, with the upper plate holder 35 provided in the center of the accommodation chamber 325 (see FIG. 4). The connection portion 55 of the upper plate assembly 50U is connected to the receiving portion 355 of the upper plate holder 35. It is preferable that the pressing force when fitting the terminals into the terminal holes be adjusted taking into account the difference in gravity with the lower plate holder 15.

[0031] Plate claws 57 are provided at two locations, one on the front and one on the rear of the plate 51. In the lower plate assembly 50L, which is held by its own weight, the plate claws 57 are not used and are housed in the relief recesses 17. On the other hand, in the upper plate assembly 50U, the plate claws 57 are engaged with the upper plate holding mechanism 37 to prevent the upper plate assembly 50U from falling.

[0032] 2, the upper plate holding mechanism 37 is configured by assembling separate components to the front and rear of the cover 30. Holding protrusions 371 are provided at two locations on each of the front and rear portions, corresponding to the plate claws 57, and a release operation portion 372 is provided at one central location. When the upper plate assembly 50U is attached to the cover 30, the plate claws 57 are engaged with the holding protrusions 371 to hold the assembly (see FIGS. 9 and 10). When the upper plate assembly 50U is removed from the cover 30, the holding protrusions 371 are retracted by placing a finger on the release operation portion 372 and sliding it outward in the front-to-rear direction, thereby releasing the plate claws 57 from their positions.

[0033] Next, referring to Figure 7, the action of the spring loads of the lower spring 61 and the upper spring 63 on the loaf of bread BR will be described. The lower spring 61 pushes up the lower plate assembly 50L via the lower plate holder 16, i.e., biases it upward. The upper spring 63 pushes down the upper plate assembly 50U via the upper plate holder 36, i.e., biases it downward. Therefore, the lower plate assembly 50L abuts against the underside of the loaf of bread BR, and the upper plate assembly 50U abuts against the top side of the loaf of bread BR. The spring loads FL, FU of the lower spring 61 and the upper spring 63 are set so that the plate assemblies 50L, 50U abut against the loaf of bread BR without excessively crushing it.

[0034] Furthermore, the weight of the upper plate assembly 50U acts on the top surface of the loaf of bread BR. Therefore, in order to average the loads acting on the top and bottom of the loaf of bread BR, the spring load FL of the lower spring 61 is set to be greater than the spring load FU of the upper spring 63.

[0035] As described above, in comparison with the conventional technology of Patent Document 1, the cooking device 100 of this embodiment heats the bread BR by heat conduction as the plates 51 of the plate assemblies 50L, 50U, each having a film heater 53 built in, come into contact with both the top and bottom surfaces of the bread BR. Furthermore, because an excessively large space is not formed around the bread BR, the amount of moisture released is minimized. This allows the surface of the bread BR to be toasted appropriately while maintaining the moisture inside, resulting in a favorable texture that combines a moist interior with a crispy surface.

[0036] Furthermore, unlike a press sandwich maker, the cooking device 100 of this embodiment does not excessively crush the bread BR while the plates 51 are in contact with the top and bottom surfaces of the bread BR, thereby preserving the original elastic texture of the bread BR.

[0037] Furthermore, the dial 70 can switch between, for example, three heating modes, allowing the user to adjust the degree of doneness depending on the thickness of the bread, the user's preferences, and the situation. While an analog system that allows for fine adjustments without steps, or a system that allows for numerical input of the heating temperature and heating time, is also possible, too much freedom can lead to confusion for the user, so a selection of around three modes is ideal. Customization is also possible, for example, by repeating the LO mode twice.

[0038] Next, referring to Figure 8, a configuration for locking the cover 30 when it is closed and unlocking the cover 30 when it is opened will be described. The left diagram in Figure 8 shows the cover 30 in a closed state. A lever 40 is provided on the front side of the cover 30 when it is closed. More specifically, the lever 40 is attached so as to protrude obliquely upward from the boundary between the top wall 311 and the front wall 312 of the cover 30.

[0039] Lever 40 has an operating portion 41 that is exposed to the outside and operated by the user, and an action portion 42 that is housed within cover 30. The action portion 42 is inserted into lever support hole 313 of cover 30, inclined so as to descend rearward from front wall 312. There is play between the base of action portion 42 and lever support hole 313. Within this angular range of play, lever 40 can swing around the point of contact between action portion 42 and lever support hole 313 as a fulcrum.

[0040] The locking member 43 has a rod-shaped cross section extending vertically, and is held inside the front wall 312 of the cover 30. The rear corner of the upper end of the locking member 43 abuts against the action portion 42 of the lever 40. A claw 44 that protrudes forward is formed at the lower end of the locking member 43. The lower portion of the locking member 43 is biased forward by a lock spring 45. The claw 44 fits into a recess 14 formed in the front wall 13 of the base 10, thereby engaging the cover 30 with the base 10 in the closed state. In this way, the cooking appliance 100 is provided with a locking mechanism that engages the cover 30 with the base 10.

[0041] The right diagram in Figure 8 shows the state in which the lever 40 has been operated in the opening direction from a state in which the cover 30 is closed. In conjunction with the operation of the lever 40, the operating portion 42 rotates downward about the fulcrum, pushing the upper end of the locking member 43 forward. This causes the lower end of the locking member 43 to move rearward, and the claw 44 disengages from the recess 14, releasing the engagement between the claw 44 and the recess 14. In this way, the cooking appliance 100 is provided with an unlocking mechanism that disengages the claw 44 from the recess 14.

[0042] When closing the cover 30, the user can feel secure because the locking mechanism ensures that the cover is securely closed. Consider a situation in which, for example, a user holds a loaf of bread in one hand and pushes up the lever 40 with the other hand to open the cover 30. The unlocking mechanism of this embodiment allows the user to operate the lever 40 with one hand to open the cover 30, improving convenience. This is ideal for situations such as when you want to quickly toast bread for breakfast when you're short on time.

[0043] Next, the configuration of the hinge portion 80 will be described with reference to Figures 5, 9, and 10. Note that Figures 9 and 10 also show a cross section of the lower plate assembly 50L, which is not shown in Figure 5. Torque hinges 81 housed in the support cylinder portions 18 of the base 10 are provided on both sides of the left-right center of the hinge portion 80. The torque hinges 81 generate frictional resistance to the opening and closing operation of the cover 30.

[0044] A return spring 82 that biases the cover 30 in the opening direction is provided in the center of the hinge portion 80 in the left-right direction. The return spring 82 is made of hardened spring steel, and has a coil portion 822 that is installed along the rotation axis of the hinge portion 80, a base-side arm 821 that extends from the coil portion 822 toward the base 10, and a cover-side arm 823 that extends from the coil portion 822 to the cover 30.

[0045] The base-side arm 821 and the cover-side arm 823 generate a repulsive force by folding from the open angle in the free state around the coil portion 822. In the process of closing the cover 30, when the end faces on the opening side of the base-side arm 821 and the cover-side arm 823 abut against the walls of the base 10 and the cover 30, respectively, the cover 30 is biased in the opening direction by the return spring 82 against the force in the closing direction due to its own weight.

[0046] In this way, in this embodiment, by using the torque hinge 81 and the return spring 82 in the hinge portion 80, it is possible to prevent the cover 30 from closing suddenly due to its own weight, which could result in the user's hand being pinched, or to prevent parts from being damaged by impact when closing the cover 30. This results in a safe product with fewer malfunctions.

[0047] (Other Embodiments) (a) The lower plate assembly 50L and the upper plate assembly 50U may be dedicated parts with distinct shapes rather than being common parts with the same shape. In this case, it is preferable to design them with foolproof considerations so that the user cannot mistakenly reinstall them after cleaning.

[0048] (b) The cooking device 100 is not limited to a configuration including both the lower spring 61 and the upper spring 63, and may include only one of the lower spring 61 or the upper spring 63. Even if a spring load is applied to one of the plate assemblies 50L, 50U, the plate 51 can be brought into contact with the upper and lower surfaces of the object to be heated, allowing for appropriate heating.

[0049] (c) As shown by the thick dashed line in Fig. 5, a vapor-deposited film VD of aluminum or the like may be formed on the inner wall of the storage chamber 125 of the base 10. The vapor-deposited film VD reflects radiant heat, improving thermal efficiency. The same applies to the storage chamber 325 of the cover 30 (see Fig. 4).

[0050] (d) The configurations of the locking mechanism and unlocking mechanism when the cover 30 is closed, the configuration of the hinge portion 80, etc. are not limited to the configurations in the above embodiment and may be set as appropriate.

[0051] As described above, the present disclosure is not limited to the above-described embodiments, and can be embodied in various forms without departing from the spirit of the present disclosure.

[0052] The present disclosure has been described based on the embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A cooking appliance that heats an object to be heated (BR) by sandwiching it vertically, comprising: a base (10); a cover (30) rotatably attached to the back side of the base via a hinge portion (80) and capable of opening and closing the upper portion of the base according to rotation; a lower plate assembly (50L) held by the base and having a film heater (53) integrally incorporated therein, with a plate (51) abutting against the lower surface of the object to be heated; an upper plate assembly (50U) held by the cover and having a film heater (53) integrally incorporated therein, with the plate (51) abutting against the upper surface of the object to be heated when the cover is closed; and at least one of a lower spring (61) that biases the lower plate assembly upward or an upper spring (63) that biases the upper plate assembly downward.

2. The cooking appliance according to claim 1, comprising both the lower spring and the upper spring, wherein the spring load of the lower spring is set to be greater than the spring load of the upper spring.

3. The cooking appliance according to claim 1 or 2, wherein the lower plate assembly is removable from the base, and the upper plate assembly is removable from the cover.

4. The hinge portion of the cooking appliance according to claim 1 or 2 has a torque hinge (81) that generates a frictional resistance force against the opening and closing operation of the cover, and a return spring (82) that biases the cover in the opening direction.

5. The cooking appliance according to claim 1 or 2 further comprises: a lever (40) provided on the front side of the cover in a state where the cover is closed; a locking mechanism that engages the cover and the base by fitting a claw (44) of a lock member (43) held by the cover into a recess (14) formed in the base in a state where the cover is closed; and a unlocking mechanism that disengages the claw from the recess in conjunction with the operation of the lever when the lever is operated in the opening direction from a state where the cover is closed.

Images