JP4011552B2 - Detection device for cooking device - Google Patents

Description

  The present invention relates to a detection device used by being assembled in a heating cooker. In particular, the present invention relates to an apparatus for detecting whether or not a cooking container such as a pan is placed on the five virtues of the heating cooker and detecting the temperature of the bottom plate of the cooking container placed on the five virtues. In the following, the former is called presence detection and the latter is called temperature detection. The present invention relates to a detection device that is used in a cooking device for presence / absence detection and temperature detection.

A detection device that is used in a heating cooker for presence / absence detection and temperature detection has been developed, and is described in Patent Documents 1 to 5 and the like.
Japanese Utility Model Publication No. 5-94735 JP-A-6-313737 Japanese Unexamined Patent Publication No. 7-43218 JP 2001-222936 A Japanese Unexamined Patent Publication No. 2000-247331

FIG. 4 shows a cross-sectional structure of a conventional detection device 50 described in Patent Documents 1 to 4. The conventional detection device 50 has an inner cylinder 52 and an outer cylinder 62. A thermal element 56 is fixed inside the upper lid 54 of the inner cylinder 52. A proximity switch 60 is supported by a member 58 that extends downward in the inner cylinder 52. The outer cylinder 62 is positioned outside the inner cylinder 52 and guides the inner cylinder 52 so as to move up and down. A magnet 68 is fixed to a rib 66 rising from the bottom plate 64 of the outer cylinder 62. The inner cylinder 52 is urged upward with respect to the outer cylinder 62 by the elastic member 70. The magnet 68 is fixed at a position close to the proximity switch 60 when the inner cylinder 52 is raised. The outer cylinder 62 is fixed to the heating cooker.
If the cooking container is placed on the five virtue of the heating cooker, the inner cylinder 52 is pushed down with respect to the outer cylinder 62, the magnet 68 is separated from the proximity switch 60, and the proximity switch 60 is turned off. If the cooking container is not placed on the virtues, the inner cylinder 52 rises with respect to the outer cylinder 62, the magnet 68 approaches the proximity switch 60, and the proximity switch 60 is turned on. Presence / absence can be detected by the proximity switch 60.
If the cooking container is placed on the five virtues, the upper lid 54 of the inner cylinder 52 is pressed against the bottom plate of the cooking container, and the temperature of the bottom plate of the cooking container is transferred to the thermal element 56. Since the output of the thermal element 56 changes according to the temperature, the temperature can be detected from the output of the thermal element 56.
The detection device 50 in which the inner cylinder 52 with lid moves up and down the inner side of the outer cylinder 62 without lid has the advantage of easily accommodating the heat sensitive element 56 and the lead wire bundle of the proximity switch 60, but the inner cylinder 52 and the outer cylinder 62. There is a problem that the broth easily enters from the gap.
As shown in FIG. 5, if the inner and outer relations of the cylinders are reversed and the outer cylinder 72 is provided with a lid 74, there is no problem that the broth easily enters from the gap between the inner cylinder 52 and the outer cylinder 62 of FIG. However, if the structure of FIG. 5 is adopted, it becomes difficult to process the lead wire of the proximity switch 60, and it cannot be adopted in reality. When the outer cylinder 72 is pushed downward, the lead wire extending from the thermal element 56 is pushed into the inner cylinder 76, and the lead wire extending from the proximity switch 60 is pulled out from the inner cylinder 76. It is difficult to store the lead wires so that the operations of the two lead wires are not impaired. Reference numeral 68 denotes a magnet.
As shown in FIG. 6, Patent Document 5 describes a detection device 80 that uses an outer cylinder 82 with a lid. However, a rod member 84 that extends downward from the outer cylinder 82 with a lid, The pin 86 that swings around the rod member 84 when moved, and the magnet swinging member 88 that swings the magnet 68 around the shaft 90 using the swing of the swinging pin 86 are very complicated. The structure is adopted. Reference numeral 56 denotes a thermal element, and reference numeral 60 denotes a proximity switch.

The structure 50 shown in FIG. 4 is simple and preferable, but has a problem that broth and the like easily enter from the gap between the inner cylinder 52 and the outer cylinder 62. The structure 70 shown in FIG. 5 does not have a problem that boiled juice or the like easily enters, but has a problem that it is difficult to process a lead wire and it is difficult to actually adopt it. If an attempt is made to be able to process lead wires while preventing the intrusion of broth or the like, a very complicated structure 80 shown in FIG. 6 is required.
The present invention proposes a detection device that can prevent the intrusion of broth and the like, can easily process lead wires, and has a simple structure.

  The detection device used in the heating cooker created in the present invention has an outer cylinder and an inner cylinder, and a thermal element is fixed inside the lid of the outer cylinder, and is brought into proximity by a lead wire bundle extending from the thermal element. The switch is supported. The inner cylinder is inserted inside the outer cylinder to guide the outer cylinder so that it can move up and down, and the lead wire bundle and proximity switch penetrate so that the inner cylinder moves up and down following the vertical movement of the outer cylinder. ing. A magnet is fixed inside the inner cylinder, and the magnet is fixed at a position close to the proximity switch when the outer cylinder is raised. The outer cylinder is biased upward by the elastic member with respect to the inner cylinder.

  The detection device created in the present invention has a problem that boiled juice or the like easily enters from the gap between the inner cylinder and the outer cylinder because the cylinder with the lid is arranged on the outside. The proximity switch is supported by a bundle of lead wires extending from the thermal element. The lead wire extending from the thermal element and the lead wire extending from the proximity switch can be bundled and processed, and the lead wire can be easily processed. The structure is simple and the whole detection device is easily unitized. Since the magnet is fixed inside the inner cylinder, the broth does not adhere to the magnet and the broth does not enter the gap between the magnet and the inner cylinder. The proximity switch moves up and down inside the inner cylinder. If the magnet is fixed inside the inner cylinder, the inner cylinder does not enter between the magnet and the proximity switch, and a strong interaction is easily obtained between the magnet and the proximity switch. Proximity switch operation is stable. Furthermore, the effect | action which a magnet protects from a heat | fever with an inner cylinder is also acquired.

  In order to fix the magnet inside the inner cylinder, a structure in which the lower part of the inner cylinder has a diameter larger than that of the upper part and a substantially ring-shaped magnet is fixed inside the enlarged diameter part is advantageous. If a substantially ring-shaped magnet is used, even if the outer cylinder and the inner cylinder rotate relative to each other, the magnet and the proximity switch will not shift in the circumferential direction.

  When a substantially ring-shaped magnet is fixed inside the inner cylinder, the diameter of the inner hole of the magnet is preferably larger than the diameter of the upper portion of the inner cylinder. When the inner hole of the magnet has a large diameter, it is easy to ensure an operation in which the proximity switch and the lead wire bundle move up and down without difficulty.

When fixing a substantially ring-shaped magnet inside the inner cylinder, the magnet is fixed to the inner cylinder with a clearance secured between the outer circumference of the magnet and the inner circumference of the inner cylinder at least in a part in the circumferential direction. It is preferable.
If a clearance is ensured between the outer periphery of the magnet and the inner periphery of the inner cylinder, it is difficult for heat to be transmitted from the inner cylinder to the magnet, and it is possible to prevent the magnet from being heated to high heat and deteriorating the magnetic characteristics.

It is preferable to use a magnet having a gap at least at one place in the circumferential direction. If a C-shaped magnet is used, a substantially ring-shaped magnet can be formed with one magnet. If a structure in which the relative positions of a plurality of magnets are maintained using a holder or the like is adopted, a ring-shaped magnet in which gaps are secured at two or more locations can be realized. However, it would be best to use a single C-shaped magnet.
When a gap is secured at least at one place in the circumferential direction, thermal deformation of the magnet is allowed, and stress acting on the magnet can be reduced. The gap here may be filled with a material that is more easily elastically deformed than the magnet. Still, the stress acting on the magnet can be reduced.

  According to the present invention, it is possible to prevent the soup from entering the detection device assembled in the heating cooker for the presence / absence detection and temperature detection of the pan, etc., and to prevent the soup from adhering to the proximity switch or magnet. can do. The durability and reliability of the detection device are improved. In addition, the detection device can be realized with a simple structure, the lead wire can be easily processed, and the manufacturing cost of the detection device can be reduced. According to the present invention, a highly durable and reliable detection device can be manufactured at low cost.

FIG. 1 shows a state in which a detection device 2 embodying the present invention is assembled to a heating cooker 14. The detection device 2 includes an inner cylinder 6 and an outer cylinder 4. The outer cylinder 4 is movable up and down with respect to the inner cylinder 6, and is urged upward by a built-in spring. The inner cylinder 6 is assembled to the heating cooker 14 using the flange 6c. The detection device 2 is assembled at the center of the virtues 12.
When the cooking container 10 such as a pan is placed on the virtues 12, the outer cylinder 4 is pushed down against the spring by its own weight, and the proximity switch described later detects that the outer cylinder 4 has been pushed down. Thereby, the presence or absence of the cooking container 10 is detected.
When the cooking container 10 such as a pan is placed on the virtues 12, the upper lid 4a of the outer cylinder 4 comes into contact with the bottom plate of the cooking container 10. A heat sensitive element, which will be described later, is fixed inside the upper lid 4a, and the temperature of the bottom plate of the cooking vessel 10 is transferred to the heat sensitive element. The temperature of the bottom plate of the cooking vessel 10 can be detected from the output of the thermal element.
Since the presence / absence detection and temperature detection can be performed by the detection device 2, it is possible to prevent the occurrence of a situation in which heating is performed even when the cooking container 10 is not placed or heating is continued even though the cooking container 10 is overheated. it can. The lead wire 8 of the detection device 2 is drawn from the inside of the inner cylinder 6 and connected to a control device (not shown) that controls the heating state of the heating cooker 14.
Since the outer cylinder 4 with the upper lid 4 a covers the outside of the inner cylinder 6, boiled juice or the like does not enter the detection device 2 from the gap between the outer cylinder 4 and the inner cylinder 6.

FIG. 2 is a longitudinal cross-sectional view of the detection device 2, which is unitized in the illustrated state, and is attached to the heating cooker 14 in the united state.
The outer cylinder 4 is configured by combining an upper lid 4a, an upper large diameter portion 4b, and a lower small diameter portion 4c. A thermistor (heat sensitive element) 18 whose resistance changes with temperature is fixed inside the upper lid 4a. The thermal element 18 is bonded to the inner surface of the upper lid 4a, and the position thereof is also fixed by the silicone grease 20 filled in the plate piece 22 fixed to the upper lid 4a, so that it is protected from the surrounding environment. Yes. Details of the thermal element 18 and the upper lid 4a are disclosed in Japanese Patent Application Laid-Open No. 11-83020 of the present applicant, and detailed description thereof is omitted.
A pair of lead wires 24 a and 24 b are drawn out from the thermal element 18, and the lead wires 24 a and 24 b are bundled and accommodated in the glass braided tube 26. The glass braided tube 26 insulates the lead wires 24a and 24b from the outside and mechanically protects them, and has high rigidity. The bundle 27 of the lead wires 24a and 24b accommodated in the glass braided tube 26 is high in rigidity and is not easily bent.

  Lead wires 28 a and 28 b connected to the control device of the heating cooker 14 are welded to the lead wires 24 a and 24 b drawn from the heat sensitive element 18. One lead wire 30b of the proximity switch 30 is also welded to the lead wire 24b. A lead wire 28 c is welded to the other lead wire 30 c of the proximity switch 30. The height of the proximity switch 30 relative to the outer cylinder 4 is fixed by a bundle 27 of lead wires 24a and 24b accommodated in a glass braided tube 26 having high rigidity. The proximity switch 30 is also accommodated in the glass braided tube 26, and the upper ends of the lead wires 28a, 28b, and 28c are also bundled and accommodated in the glass braided tube 26. The rigidity of the bundle 27 of the lead wires 24a, 24b, 28a, 28b, and 28c bundled by the glass braided tube 26 is sufficiently higher than the rigidity of the bundle 8 of the lead wires 28a, 28b, and 28c that are not bundled by the glass braided tube 26. Very expensive. When the outer cylinder 4 moves up and down, the lead wire bundle 8 not bundled by the glass braided tube 26 bends and follows the vertical movement, and the lead wire bundle 27 bundled by the glass braided tube 26 does not bend. The relative positional relationship between the outer cylinder 4 and the proximity switch 30 is fixed by a lead wire bundle 27 bundled by a glass braided tube 26 having high rigidity, and is not relatively displaced.

The entire lead wire bundle 27 including the proximity switch 30 and the outer cylinder 4 are guided by the inner cylinder 6 so as to be movable up and down. The inner cylinder 6 is formed by integrating a spring receiver 6a, an upper small diameter portion 6b, a rib 6c, and a lower large diameter portion 6d. The spring receiver 6a receives the compressed spring 16 and urges the outer cylinder 4 upward. The upper small diameter portion 6b guides the lower small diameter portion 4c of the outer cylinder 4 and guides the outer cylinder 4 so as to be movable up and down. The rib 6c is used for assembling the detection device 2 to the cooking device 14 (see FIG. 1). The lower large-diameter portion 6d is used for fixing the substantially ring-shaped magnet 32 inside. The magnet 32 is fixed at a height facing the proximity switch 30 when the outer cylinder 4 is fully raised (shown in FIG. 2). At this time, since the magnet 32 is close to the proximity switch 30, the proximity switch 30 is turned on. When the cooking container 10 is placed on the virtues 12, the outer cylinder 4 is lowered, and the proximity switch 30 is also lowered following that. When the proximity switch 30 is lowered, the proximity switch 30 is turned off because the proximity switch 30 is separated from the magnet 32. Actually, the proximity switch 30 is turned off when the outer cylinder 4 is lowered 2 mm from the natural position.
A constant voltage is applied to the lead wire 28b from the controller of the heating cooker 14. The control device watches the potential of the lead wire 28c. If the potential of the lead wire 28c is equal to the potential of the lead wire 28b, the proximity switch 30 is turned on, and it is detected that the cooking container 10 is not placed on the virtues 12. The control device also observes the potential of the lead wire 28a. The potential of the lead wire 28a changes as the resistance of the thermal element 18 changes. The resistance of the thermal element 18 changes following the temperature. The resistance of the thermal element 18 is detected from the potential of the lead wire 28a, the temperature of the thermal element 18 is detected from the resistance of the thermal element 18, and the temperature of the bottom plate of the cooking vessel 10 placed on the virtues 12 is detected.
The control device of the heating cooker detects the detection result (presence / absence detection result) of whether or not the cooking container 10 is placed on the virtues 12 and the detection result (temperature) of the bottom plate temperature of the cooking container 10 placed on the virtues 12. From the detection result, the heating amount of the heating cooker 14 is controlled, and heating is stopped as necessary.

As shown in FIG. 1, the part of the detection device 2 where the magnet and the proximity switch are present is located below the burner 15 of the heating cooker 14, and therefore is not easily affected by heat. However, it is not completely immune to heat.
In order to prevent the magnet 32 and the proximity switch 30 from being affected by heat, the following measures are taken.
The magnet 32 and the proximity switch 30 are located inside the inner cylinder 6 and are protected from heat by the inner cylinder 6. In order to further insulate, a clearance 34 is secured between the inner periphery of the inner cylinder 6 and the outer periphery of the magnet 32 as shown in FIG. The inner cylinder 6 is formed with ribs 6e at three locations at equal intervals in the circumferential direction, and adopts a structure in which the magnet 32 is press-fitted and fixed. The inner cylinder 6 and the magnet 32 are only partially in contact with each other, and heat is hardly transmitted to the magnet 32.
The magnet 32 has a ring shape so that the proximity switch 30 and the magnet 32 face each other even when the inner cylinder 6 and the outer cylinder 4 rotate. However, when a seamless ring-shaped magnet is employed, a large stress is applied to the magnet when the magnet is thermally expanded, and the magnet may be damaged. Therefore, a C-shaped substantially ring shape in which the gap 32a is formed at one place is adopted. When the gap 32a is prepared, even if the magnet 32 is thermally expanded, no great stress is applied to the magnet 32, and the magnet 32 can be prevented from being damaged.
When the magnet 32 is fixed inside the inner cylinder 6, a positional relationship in which the proximity switch 30 and the magnet 32 directly face each other is obtained, and the detection operation of the proximity switch 30 is stabilized. Further, the broth or the like does not adhere to the magnet 32.
If the lower large-diameter portion 6 d is prepared in the inner cylinder 6, the magnet 32 having an inner peripheral diameter larger than the inner peripheral diameter of the small-diameter portion 6 b can be accommodated in the inner cylinder 6. When the magnet 32 having a large inner peripheral diameter is used, the lead wire bundle 27 whose outer shape is thick due to the presence of the proximity switch 30 strongly rubs against the inner peripheral surface of the magnet 32, and the lead wire bundle 27 moves up and down with respect to the magnet 32. The proximity switch 30 can move up and down smoothly with respect to the magnet 32 without being hindered. The wall that changes from the small diameter portion 6b to the lower large diameter portion 6d also contributes to fixing the position of the magnet 32 in the vertical direction. It is also possible to employ a structure in which the magnet 32 is fixed by press-fitting a cylinder (not shown) from below the lower large-diameter portion 6d that houses the magnet 32. If the cylinder to be press-fitted is formed of a heat insulating material, the cylinder for fixing the magnet also serves as a heat insulating member.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The figure which shows the heating cooker 14 with which the detection apparatus 2 is assembled | attached. The figure which shows the cross section of the detection apparatus. The figure which shows the III-III line cross section of FIG. The figure which shows the 1st example of the conventional detection apparatus. The figure which shows the 2nd example of the conventional detection apparatus. The figure which shows the 3rd example of the conventional detection apparatus.

Explanation of symbols

2: Detection device 4: Outer cylinder 6: Inner cylinder 8: Lead wire 10: Cooking container 12: Gotoku 14: Heat cooker 16: Spring (elastic member)
18: Thermal element (thermistor)
27: Lead wire bundle 30: Proximity switch 32: Magnet

Claims (5)

It is a detection device used in a heating cooker, has an outer cylinder and an inner cylinder,
A thermal element is fixed inside the lid of the outer cylinder, and the proximity switch is supported by a bundle of lead wires extending from the thermal element.
The inner cylinder is inserted inside the outer cylinder to guide the outer cylinder so that it can move up and down, and the lead wire bundle and proximity switch penetrate so that the inner cylinder moves up and down following the vertical movement of the outer cylinder. The magnet is fixed inside the inner cylinder at a position close to the proximity switch when the outer cylinder is raised,
An outer cylinder is urged upward with respect to an inner cylinder by an elastic member. 2. The detection device according to claim 1, wherein the lower part of the inner cylinder has a larger diameter than the upper part, and a substantially ring-shaped magnet is fixed inside the enlarged part. 3. The detection device according to claim 2, wherein the diameter of the inner hole of the substantially ring-shaped magnet is larger than the diameter of the upper portion of the inner cylinder. The magnet is fixed to the inner cylinder with a clearance secured between the outer circumference of the magnet and the inner circumference of the inner cylinder at least in a part in the circumferential direction. Detection device. 5. The detection device according to claim 1, wherein a substantially ring-shaped magnet having a gap at least at one place in the circumferential direction is fixed to the inner cylinder.

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