JP5057473B2 - Gas cooker sensor - Google Patents

Description

  The present invention relates to a gas cooker sensor for detecting that a cooking tool such as a pan is placed on a gas burner of a gas table or a gas stove.

  Conventionally, a gas table or a gas stove has been provided with a sensor for detecting that a cooking tool such as a pan is placed. As a gas cooker sensor, for example, there are sensor devices as disclosed in Patent Documents 1 and 2. This sensor device is composed of a combination of a reed switch, a magnetic body, and a permanent magnet, and a contact portion elastically biased in a protruding state is located at the center of a gas burner such as a gas table. When a pan or the like is placed on the gas burner during use, the abutting portion comes into contact with the bottom of the pan or the like and descends, and the magnetic body is movably provided together with the cable connected to the abutting portion. . The magnetic body is located between the reed switch and the magnet and shields the magnetic field of the magnet. When the magnetic body moves as the contact part moves down, the magnetic field of the magnet is transmitted to the reed switch, and the reed switch is turned on. It detects the pan and the like.

  Patent Document 1 discloses a gas cooker equipped with a temperature detection device using a thermistor. The thermistor is disposed at a contact portion that is pushed down by placing the cooking utensil, and a thermistor cable includes a reed switch and a magnetic switch. A shielding member or the like is arranged, a magnet is provided at a predetermined position in the moving range, and the movement of the contact portion due to the placement of the cooking utensil is detected by a reed switch. In the detection operation, the reed switch is turned on / off by controlling the magnetic field applied to the reed switch by the magnetic body as the magnetic shielding member by the movement of the contact portion.

Patent document 2 is also a device that detects whether or not a pan or the like of a heating cooker is placed, and detects the temperature of the bottom plate of the pan or the like, and is a detection device such as a pan in the cooking device. In this detection device, a heat sensitive element is fixed inside a lid of an outer cylinder, and a proximity switch is supported by a lead wire bundle extending from the heat sensitive 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. ing. And the magnet is provided in the position close | similar to the proximity switch when an outer cylinder raises, and it can detect a pan.
JP 2006-34783 A JP 2005-214473 A

  In the above conventional technique, a ferrite magnet is used as a magnet for turning on and off the reed switch. However, when the ferrite magnet is heated by the heat transmitted from the gas burner, the magnetic force is reduced and the position where the reed switch is turned on is shifted. Therefore, the reed switch disclosed in Patent Document 1 is disposed at a distance so as not to be affected by the heat of the gas burner.

  In Cited Document 1, the magnetic material is fixed on the lead wire, and in Cited Document 2, the proximity switch is fixed on the lead wire. In these structures, the relative positional accuracy with the magnet is unstable. It was. Furthermore, since the positioning accuracy of the reed switch and the magnet varies greatly, positioning adjustment is required for each individual product, which increases the manufacturing cost.

  Furthermore, if you try to install a reed switch, magnet, etc. away from the gas burner to avoid the effects of heat, the space occupied by this detector will increase, depriving the design freedom of the gas cooker, and reducing the size and thickness. It was a hindrance.

  The present invention has been made in view of the above problems of the background art, and provides a gas cooker sensor that has a simple structure, high heat resistance, low performance degradation due to heat, and low cost. With the goal.

  The present invention includes an abutting portion that is elastically biased in a protruding direction to detect that the cooking utensil is placed on the gas cooker and abuts on the cooking utensil and retracts by placing the cooking utensil. A support shaft connected to the contact portion and supporting the contact portion so as to protrude and retract, an interlocking member inserted through the support shaft and connected to the contact portion, and fixed to a predetermined position of the interlocking member. Made of a rare earth material such as samarium cobalt disposed at a position facing the magnetic body when the contact portion protrudes in a range in which the magnetic body moves in conjunction with the movement of the contact portion. A gas cooker sensor comprising a permanent magnet having heat resistance, and a reed switch facing the permanent magnet and having a difference between a moving value and an open value of 3 AT or less, preferably 2.0 to 1.5 AT. .

The permanent magnet is housed in one case having the housing portion in the shape of the permanent magnet, the reed switch is housed in the other case having the housing portion in the shape of the reed switch, and the cases are mutually connected. It is formed in a cylindrical shape so as to face each other, and is concentrically and integrally fixed to the side surface of the end surface portion of the support shaft.

The magnetic body is a plate that protrudes from a slit formed on a side surface of the support shaft and moves in the longitudinal direction of the support shaft in conjunction with the movement of the interlocking member.

  The interlocking member is a cable extending from a temperature sensor provided at the contact portion. Alternatively, the interlocking member is an interlocking cylinder member that is locked to a holder that holds the abutting portion and is coaxially fitted to the support shaft so as to be movable. Further, the magnetic body is formed in a cylindrical shape and is provided coaxially and integrally on the end surface of the interlocking cylinder member, and moves in the longitudinal direction within the support shaft in conjunction with the movement of the interlocking member. is there.

  In the gas cooker sensor according to the present invention, the rare-earth permanent magnet fixed to the support shaft and the reed switch are linearly provided.

  According to the gas cooker sensor of the present invention, the position of the reed switch does not need to be greatly separated from the gas burner, which contributes to downsizing of the gas stove. Furthermore, the structure is simple, the cost is low, and adjustment is easy. Moreover, since the detection accuracy change due to heat does not occur, it is possible to detect cooking utensils and the like and to detect the temperature with high accuracy and stability.

  In particular, by suppressing the hysteresis of the on / off position of the reed switch to a minimum, products out of specification due to variations in the manufacturing process do not occur. Further, the position of each component is set accurately, so that position adjustment in the manufacturing process is not necessary, and the number of manufacturing steps can be reduced.

  In addition, since the heat resistance is high, the sensor unit can be arranged immediately below the burner flame, the entire sensor device is downsized, and the degree of freedom in design inside the gas cooker is improved.

  Hereinafter, an embodiment of a sensor for a gas cooker according to the present invention will be described with reference to FIGS. The structure of the contact part 10 in the upper part of the sensor for gas cookers of this embodiment is a structure as shown, for example in FIG. A disc-shaped heat collecting plate 12 formed by processing metal is provided at the upper end, and a thermistor 14 as a temperature sensor is fitted to the back surface of the heat collecting plate 12. An upper end portion of a cylindrical holder 16 is fixed to the heat collecting plate 12.

  A cable 20 extending from the thermistor 14 located at the upper end is inserted into the holder 16, and a coil spring 22 is concentrically housed outside the cable 20. The upper end of the coil spring 22 is in contact with the back surface of the heat collecting plate 12, and the lower end is in contact with a stopper 24 that guides and positions the holder 16 so as to be relatively slidable. The stopper 24 is fixed to an upper end portion of a support shaft 26 fixed to a gas cooker main body (not shown). The holder 16 urged by the coil spring 22 is provided such that the locking step 16a positioned below the elastic spring 16 abuts on the stopper 24 and stops, and is slidable downward. The stopper 24 is formed in an annular shape, and a distal end portion of a tubular support shaft 26 is fixed to the central through hole, and the support shaft 26 is inserted into the holder 16 so as to advance and retract. A cable 20 extending from the thermistor 14 is inserted into the support shaft 26. A cylindrical cover 18 is integrally attached to the holder 16.

  As shown in FIGS. 1 and 3, a heat-resistant permanent magnet 30 made of rare earth such as samarium cobalt is fixed below the support shaft 26, and on the opposite side of the permanent magnet 30 across the support shaft 26. The reed switch 32 is fixed. The rare earth permanent magnet 30 has heat resistance that enables the reed switch 32 to be turned on / off even in an environment of 300 ° C. Further, the permanent magnet 30 is aged in advance at 300 ° C. in order to cancel the demagnetization at a high temperature.

  The reed switch 32 faces the permanent magnet 30 and has a hysteresis that is a difference between the moving value and the open value of 3AT or less, preferably 2.0 to 1.5AT. In order to reduce the hysteresis in the operation of the reed switch 32, it is better that the hysteresis is smaller. Actually, 1AT or less is possible, but there is a problem that the yield is very bad and the cost is increased. Therefore, in view of mass productivity, it can be said that the above range is appropriate at 3AT or less. Here, the moving value of the reed switch is a product of a current value necessary for operating the contact by coil excitation and the number of coil turns. The open value is the product of the current value at which the operating contact is restored by coil excitation and the number of coil turns, and has a correlation with the moving value. These units are represented by (AT) because they are the product of the current (A) during operation and the number of standard coil turns (5000 T).

  The cable 20 extending from the thermistor 14 of the contact portion 10 functions as an interlocking member that interlocks with the contact portion 10, and between the permanent magnet 30 and the reed switch 32, as shown in FIG. Thus, a magnetic cylinder 34 such as a ferromagnetic metal that can move with the cable 20 in the support shaft 26 is fixed, and moves forward and backward together with the abutting portion 10. The magnetic cylinder 34 is positioned between the permanent magnet 30 and the reed switch 32 with the abutting portion 10 protruding from the gas cooker, shields the magnetism of the permanent magnet 30 and turns off the reed switch 32. The position to maintain. When the pan or the like is placed on the stove and the abutting portion 10 moves downward, the magnetic cylinder 34 also moves downward, and the reed switch 32 is operated by the magnetic field of the permanent magnet 30. A pair of flexible lead wires 33 are connected to the terminals 32 a at both ends of the reed switch 32 and extend in parallel with the cable 20 from the thermistor 14.

  Next, the operation of this gas cooker sensor will be described. As shown in FIG. 2, when a cooking utensil 28 such as a pan is placed on a gas cooker (not shown), the bottom surface of the cooking utensil 28 abuts on the heat collecting plate 12 of the abutting portion 10 and the abutting portion 10 is moved downward. Slide. Thereby, the cable 20 interlock | cooperated with the contact part 10 moves below, and the magnetic body cylinder 34 also moves below with the cable 20. FIG.

  The magnetic cylinder 34 is located between the permanent magnet 30 and the reed switch 32 with the abutting portion 10 protruding, and shields the magnetism of the permanent magnet 30 so that the reed switch 32 is not turned on. When the utensil 28 such as a pan is placed on the stove and the contact portion 10 moves downward, the magnetic cylinder 34 moves downward, and the magnetic field of the permanent magnet 30 acts on the reed switch 32. Thereby, the reed switch 32 is turned on, and it is detected that a pan or the like has been placed on the stove.

  According to the gas cooker sensor of this embodiment, the permanent magnet 30 is made of a heat-resistant rare earth, and the magnetic flux density of the magnetic field does not drop even in a high temperature environment, and a good magnetic field can be exerted on the reed switch 32. Therefore, it is not necessary to separate the permanent magnet 30 and the reed switch 32 from the burner of the stove, which contributes to downsizing of the device.

  Further, since the hysteresis between the moving value and the open value of the reed switch 32 is set to 3AT or less, there is little difference in the on / off operation of the reed switch contact, and this can also reduce the reed switch 32 hysteresis.

  Furthermore, due to the miniaturization, the detection sensor of the cooking utensil can be arranged in a linear shape directly under the burner of the gas cooker, and is arranged in a space of, for example, 72%, compared with the conventional L-shaped one I can do it.

  Next, an embodiment of a sensor for a gas cooker according to the present invention will be described with reference to FIGS. Here, the same members as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIGS. 5 and 6, the structure of the contact portion 40 at the upper part of the gas cooker sensor of this embodiment is provided with a disk-shaped heat collecting plate 12 formed by processing metal at the upper end portion. The thermistor 14 as a temperature sensor is fitted in the recess 12a formed on the back surface of the heat collecting plate 12. The heat collecting plate 12 is fixed to the tip of a thin cylindrical portion 44 on the upper portion of the cylindrical holder 42.

  The cable 20 extending from the thermistor 14 located at the upper end portion is inserted into the cylindrical portion 44 of the holder 42, passes through the holder 42, and is inserted into the support shaft 26. In the holder 42, an interlocking cylinder member 48 that is also an interlocking member through which the cable 22 is inserted is provided concentrically. The interlocking cylinder member 48 has a collar portion 48a fixed to the upper end, abuts against a shoulder portion 42a at the boundary between the holder 42 and the cylindrical portion 44, and the interlocking cylinder member 48 positioned above the collar portion 48a has a cylindrical portion. 44 is fitted. A coil spring 46 wound in the shape of a truncated cone is inserted below the flange portion 48a of the interlocking cylinder member 48, the small-diameter end portion of the coil spring 46 abuts the flange portion 48a, and the large-diameter end portion is The holder 42 is in contact with the flange portion 26 a at the tip of the support shaft 26. Furthermore, the magnetic cylinder 50 inserted into the support shaft 26 is integrally and coaxially welded to the end on the support shaft 26 side which is the lower end of the interlocking cylinder member 48. A base end portion of the support shaft 26 is fixed to an attachment member 60 fixed to a gas cooker main body (not shown).

  A pair of semi-cylindrical case members 52a and 52b formed of heat-resistant resin or the like are fixed to the distal end portion of the support shaft 26 into which the magnetic cylinder 50 is inserted. As shown in FIGS. 7 and 8, the case member 52 a is formed with a housing portion 54 that is a rectangular recess inside the center portion, and the rare-earth permanent magnet 30 is housed therein. As shown in FIGS. 9 and 10, the case member 52 b is formed with a receiving portion 56 that is a cylindrical recess at the center, and grooves 56 a and 56 b are formed at both ends of the receiving portion 56. It is curved in a letter shape and communicates with a slit 57 formed in parallel with the accommodating portion 56. The slit 57 is open to the end surface where the groove 56a is formed. The reed switch 32 is accommodated in the accommodating portion 56, the pair of terminals 32 a of the reed switch 32 are accommodated in the grooves 56 a and 56 b, and the terminal 32 a inserted into the groove 56 a protrudes from the end surface of the case member 52 B, and leads 33 Connected to one of the two. Further, the terminal 32a is folded back from the groove 56b, inserted into the slit 57, connected to the other end of the lead wire 33, and a pair of lead wires 33 extends from the end surface of the case 52b.

  The case members 52a and 52b are fitted to the tip of the support shaft 26 in a state where the permanent magnet 30 and the reed switch 32 are accommodated, and are fixed by a fixing member (not shown). The support shaft 26 and the interlocking cylinder member 48 are urged in a direction away from the holder 42 by a coil spring 46, and are locked by a stopper 45 provided at an end opening portion of the holder 42. In this state, the magnetic cylinder 50 is stopped at the position where it is inserted into the distal end portion of the support shaft 26, and is accurately positioned between the permanent magnet 30 and the reed switch 32.

  The gas cooker sensor of this embodiment also operates in the same manner as in the above embodiment. When a cooking utensil such as a pan is placed on the stove of the gas cooker, the contact portion 40 is retracted downward, and the holder 42 Go down. Then, the interlocking cylinder member 48 slides downward, and the magnetic cylinder 50 at the lower end slides downward within the support shaft 26. Thereby, the magnetic field of the permanent magnet 30 acts on the reed switch 32, turns on the reed switch 32, and can detect a cooking utensil.

  The gas cooker sensor of this embodiment also has the same effect as that of the above embodiment, and further, the movement of the contact portion 40 is transmitted to the cylindrical interlocking cylinder member 48, so that the play of movement is small, and the magnetic body The cylinder 50 moves more accurately, and the cooking utensil can be reliably detected. Further, by using the case members 52a and 52b, it is possible to easily realize high accuracy of the relative position between the reed switch 32 and the permanent magnet 30. Furthermore, the relative positional accuracy of the reed switch 32, the permanent magnet 30, and the magnetic cylinder 50 during assembly can be increased, the operating position can be stabilized, and no adjustment can be achieved during the manufacturing process.

  The gas cooker sensor of the present invention is not limited to the above embodiment. As shown in FIG. 11A, a slit 26a is provided in the longitudinal direction of the support shaft 26, and a magnetic material is provided in the slit 26a. A plate body 36a protruding from the side surface of the cylinder 36 may be inserted. In this operation, as shown in FIGS. 11B and 11C, the cooking tool is detected when the plate 36 a is retracted from the state where the plate 36 a is located between the permanent magnet 30 and the reed switch 32. . In this case, the permanent magnet 30 and the reed switch 32 may be provided with the plate 36a interposed therebetween, so that both of them can be brought closer to each other to be slightly wider than the thickness of the plate 36a, and the operation is performed at a position where the magnetic field is stronger. Therefore, the rare earth permanent magnet 30 can be made smaller.

  Furthermore, the shape and reed switch of the magnetic material can be selected as appropriate, and the shape and material of each member can be changed as appropriate.

  Hereinafter, measured values of the reed switch and the permanent magnet according to one embodiment of the present invention will be described. First, Table 1 and the graph of FIG. 12 show the measurement results of the relationship between the hysteresis of the reed switch 32 and the hysteresis between the sensitivity value and the open value.

表１及びグラフより、感動値と開放値の応差が低くなるにつれて、ヒステリシスは低くなることが分かる。

From Table 1 and the graph, it can be seen that the hysteresis decreases as the hysteresis between the impression value and the open value decreases.

  Further, when the samarium-cobalt permanent magnet 30 of this example was raised from room temperature to 300 ° C., the deviation of the position of the magnetic cylinder 34 where the reed switch 32 was turned on was 0.8 mm. On the other hand, when a conventional ferrite magnet is used, when the temperature is raised from room temperature to 240 ° C., the deviation of the position of the magnetic body where the reed switch is turned on is 4.1 mm, which depends on the temperature change. It was beyond the allowable range of displacement. Furthermore, when the ferrite magnet was set to 300 ° C., the reed switch 32 could not be turned on due to a large demagnetization.

It is a schematic side view which shows embodiment of the sensor for gas cookers . It is an expansion longitudinal cross-sectional view of the contact part of the sensor for gas cookers of this embodiment. It is the schematic which shows the reed switch of the sensor for gas cookers of this embodiment, a magnet, and a magnetic body. It is a schematic cross-sectional view which shows the reed switch of the sensor for gas cookers of this embodiment, a magnet, and a magnetic body. It is a schematic side view which shows the sensor for gas cookers of embodiment of this invention. It is an expansion longitudinal cross-sectional view of the contact part of the sensor for gas cookers of embodiment of this invention. It is the side view (a) and front view (b) of one case member of the sensor for gas cookers of embodiment of this invention. They are AA sectional drawing (a) of FIG. 7, and BB sectional drawing (b). It is the side view (a) and front view (b) of the other case member of the sensor for gas cookers of embodiment of this invention. They are AA sectional drawing (a) of FIG. 9 , and BB sectional drawing (b). The schematic cross-sectional view (a) which shows the reed switch, magnet, and magnetic body of other embodiment of the sensor for gas cookers of this invention, the partial side view (b) which shows the state before detection, and the part which shows the state after detection It is a side view (c). It is a graph which shows the measurement result of the hysteresis of a reed switch used for the sensor for gas cookers of one Example of this invention, and hysteresis.

DESCRIPTION OF SYMBOLS 10 Contact part 12 Heat collecting plate 14 Thermistor 20 Cable 22 Coil spring 26 Support shaft 28 Cooking tool 30 Permanent magnet 32 Reed switch 32a Terminal 34 Magnetic body cylinder

Claims (6)

A contact portion that is elastically biased in a protruding direction to detect that the cooking utensil is placed on the gas cooker, and abuts on the cooking utensil and retracts by placing the cooking utensil; and the abutment A support shaft that is connected to the support portion and supports the contact portion so as to protrude and retract, an interlocking member that is inserted through the support shaft and connected to the contact portion, and a magnetic body that is fixed at a predetermined position of the interlocking member; A rare-earth heat-resistant permanent magnet disposed at a position facing the magnetic body when the contact portion protrudes in a range in which the magnetic body moves in conjunction with the movement of the contact portion; A reed switch facing the permanent magnet and having a hysteresis between a moving value and an open value of 3AT or less; the permanent magnet is housed in one case having a housing portion in the shape of the permanent magnet; and the reed switch In the other case having the storage portion of the shape Dosuitchi are accommodated, each case is formed in a cylindrical shape are opposed to each other, the gas cooking appliance sensors, characterized in that is concentrically integrally fixed to the end face side of the support shaft. A contact portion that is elastically biased in a protruding direction to detect that the cooking utensil is placed on the gas cooker, and abuts on the cooking utensil and retracts by placing the cooking utensil; and the abutment A support shaft that is connected to the support portion and supports the contact portion so as to protrude and retract, an interlocking member that is inserted through the support shaft and connected to the contact portion, and a magnetic body that is fixed at a predetermined position of the interlocking member; A rare-earth heat-resistant permanent magnet disposed at a position facing the magnetic body when the contact portion protrudes in a range in which the magnetic body moves in conjunction with the movement of the contact portion; Opposite this permanent magnet, it is equipped with a reed switch whose sensitivity value and opening value have a hysteresis of 3AT or less. To move in the longitudinal direction of the support shaft Gas cooker sensor, which is a plate body.   The gas cooker sensor according to claim 1 or 2, wherein the interlocking member is a cable extending from a temperature sensor provided at the contact portion.   The sensor for a gas cooker according to claim 1 or 2, wherein the interlocking member is an interlocking cylindrical member that is locked to a holder that holds the abutting portion and that is coaxially fitted to the support shaft to be movable. .   The magnetic body is formed in a cylindrical shape and is provided coaxially and integrally on an end surface of the interlocking cylinder member, and moves in the longitudinal direction within the support shaft in conjunction with the movement of the interlocking member. Item 2. A gas cooker sensor according to Item 1.   The gas cooker sensor according to claim 1 or 2, wherein from the abutting portion to a rare earth permanent magnet fixed to the support shaft and a reed switch are linearly provided.

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