JP2000283469A - High frequency heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electromagnetic wave in a heating chamber from passing through the motor shaft penetrating part and leaking through a gap for heat insulating a motor fixing plate and a motor due to antenna effect of the side pressure spring of a weight sensor motor. SOLUTION: A conical reducing section 10c is provided at the motor shaft penetrating part 10a of a motor fixing plate 10 and small protrusions 10b are provided, at a constant interval, on the outer circumference at the base part of the conical reducing section 10c. A simple and highly reliable structure for preventing leakage of electromagnetic wave can be obtained inexpensively without requiring any extra component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating apparatus for heating food, and more particularly to a microwave oven-type high-frequency heating apparatus equipped with a motor incorporating a weight sensor.

[0002]

2. Description of the Related Art Conventionally, this kind of high-frequency heating apparatus is shown in FIGS.
As shown in FIG. 10, a fixture 3 for fixing the heating means 2 attached to the bottom plate of the heating chamber 1 is joined by spot welding or the like, and a motor mounting plate 4 is fastened to the fixture 3, and the motor The motor 5a in which the weight sensor 5 is mounted on the mounting plate 4 is fastened with screws or the like so as to be suspended. The weight sensor 5 measures the initial weight of the object 6 to be heated, or the weight after being heated by the heating means 2,
Alternatively, by measuring the change in weight, information for determining the optimal heating time or heating amount is provided. The sensor accuracy of the weight sensor 5 depends on the object 6 to be heated.
It is considered that it is easy to depend on the shape and the position where the object 6 is placed. Therefore, a structure has been proposed in which the variation in the detected weight is suppressed as much as possible without depending on the position of the object 6 to be heated, and the sensor accuracy is secured. I have. The motor 5a has a configuration in which a resin ring 5c and a side pressure spring 5d are attached to a motor shaft 5b in order to ensure sensor accuracy. In this way, even when the object to be heated 6 is placed at a position deviated from the center, the fluctuation of the load transmitted to the weight sensor 5 via the motor shaft 5b is minimized by the resin ring 5c and the side pressure spring 5d. Sensor accuracy can be ensured.

In the conventional motor mounting plate 4, in order to mount the motor 5a in which the weight sensor 5 is incorporated, the resin ring 5c mounted on the motor shaft 5b and the side pressure spring 5d should not interfere with the motor shaft penetrating portion 4a. In addition, a cylindrical throttle portion 4b for escape is provided in the motor shaft penetration portion 4a. It is known that the inner diameter of the motor shaft penetrating portion 4a greatly affects electromagnetic wave leakage due to electromagnetic wave radiation from the bottom surface of the heating chamber 1 and hot air leakage due to heat transmission and the like. A water-resistant structure is also required to prevent insulation deterioration of the heating means 2 and the charged part such as the motor 5a due to water overflow from the object 6 to be heated.
It prevents the water from flowing directly from d. In addition, the motor mounting plate 4 and the motor 5a are designed to have a constant gap L except for the screw fastening portion in order to minimize a temperature rise due to heat conduction from the heating chamber 1 at a contact surface between the motor mounting plate 4 and the motor 5a. .

[0004]

In the conventional high-frequency heating apparatus, the weight sensor is provided so that the resin ring 5c and the side pressure spring 5d provided to suppress the variation of the detected weight due to the unbalanced load of the object 6 to be heated do not interfere with or contact the side. In order to mount a motor 5a into which the motor 5 is incorporated, a cylindrical throttle portion 4b for relief is provided in the motor shaft penetration portion 4a of the motor mounting plate 4. However, the side pressure spring 5d becomes a kind of high-frequency electromagnetic wave derivative, and the radiation of high-frequency electromagnetic waves from inside the heating chamber 1 passes through the motor shaft penetration portion 4a, and is larger than the gap for heat insulation between the motor mounting plate 4 and the motor 5a. Leakage affects electronic circuits (not shown) of an inverter control unit that controls high-frequency electromagnetic waves that irradiate the object 6 to be heated in the heating chamber 1, causing malfunctions and destruction of electronic components. We needed to take measures. further,
The overflow from the motor shaft penetration 4a is prevented by the draining washer 5e inserted into the motor shaft 4b in response to the flow along the motor shaft 5b. There was also a risk of overflow from the shape restrictor 4b. In addition, due to the drawing workability of the motor mounting plate 4, the flange height H of the cylindrical drawn portion 4b could not be formed too high in consideration of the inner diameter.

[0005] That is, the motor mounting plate 4 and the motor 5a are provided with a gap for heat insulation, while the motor shaft penetrating portion 4a is provided.
Has an opening with a narrowed tip in consideration of workability,
Leakage of high-frequency electromagnetic waves from the motor shaft penetrating part 4a is required while maintaining a configuration that can cope with water leakage and hot air leakage from inside the heating chamber 1 and that does not affect the electronic circuit of the inverter control unit. It was necessary to develop a configuration that kept it low enough.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a motor mounting plate, wherein a conical constricted portion having a narrowed end is formed in a motor shaft penetrating portion, and a base portion of the conical constricted portion is formed. In the gap between the motor mounting plate and the motor on the outer circumference,
A contact member having a small heat capacity which is close to or in contact with the motor is provided.

[0007] According to the above invention, with a simple structure provided in the gap between the motor mounting plate and the motor, water leakage from the heating chamber through the motor shaft penetrating portion and the heat insulating effect of the gap between the motor and the motor mounting plate. It is possible to provide an electromagnetic wave leakage prevention function while maintaining the same.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a heating chamber for taking in and out an object to be heated, a heating means attached to a bottom plate of the heating chamber, a fixing fitting for fixing the heating means, a motor mounting plate fastened to the fixing fitting. A small heat capacity contact member that forms a conical constriction in the motor shaft penetration part of the motor mounting plate, and is close to or in contact with the motor in the gap between the motor mounting plate and the motor on the outer periphery of the base of the conical constriction. Are provided.

With this configuration, the motor mounting plate and the motor can be indirectly electromagnetically grounded by the contact member, so that there is no need to modify or change the motor mounting plate or the motor, and the motor shaft penetrating portion is not required. The electromagnetic wave leakage from the device can be sufficiently suppressed, and the reliability of the high-frequency heating device can be improved.

A heating chamber for taking in and out the object to be heated;
Heating means attached to the bottom plate of the heating chamber, a fixture for fixing the heating means, and a motor mounting plate fastened to the fixture,
A conical constriction is formed in the motor shaft penetration portion of the motor mounting plate, and a projection is provided on the outer periphery of the base of the conical constriction so as to approach or contact the motor.

[0011] With this configuration, the motor mounting plate and the motor can be grounded electromagnetically.
Electromagnetic wave leakage from the through portion of the motor shaft can be suppressed sufficiently low, and the reliability of the high-frequency heating device can be improved.

A heating chamber for taking in and out the object to be heated;
Heating means attached to the bottom plate of the heating chamber, a fixture for fixing the heating means, and a motor mounting plate fastened to the fixture,
A conical throttle portion is formed in a motor shaft penetration portion of a motor mounting plate, and a bead portion is provided on an outer periphery of a base portion of the conical throttle portion, so as to approach or contact the motor.

[0013] By providing a bead on the outer periphery of the base of the conical constricted portion of the motor shaft penetrating portion, the electromagnetic ground between the motor mounting plate and the motor can be made more reliable and strong. Electromagnetic wave leakage from the motor shaft penetration can be kept sufficiently lower than the protrusions, and there is also room for variation in the fastening between the motor mounting plate and the motor, so processing costs can be reduced and cost benefits. Can be brought.

A heating chamber for taking in and out the object to be heated;
Heating means attached to the bottom plate of the heating chamber, a fixture for fixing the heating means, and a motor mounting plate fastened to the fixture,
A conical throttle is formed in the motor shaft penetration part of the motor mounting plate, and a throttle is provided at the base of the conical throttle at a portion orthogonal to the motor side pressure spring, and brought into close proximity to or contact with the motor side pressure spring. is there.

According to this configuration, the side pressure spring of the motor and the motor mounting plate, which are particularly high electromagnetic wave intensity parts, can be electromagnetically grounded, and the leakage of electromagnetic waves can be suppressed at the most efficient part. Therefore, the motor mounting plate can be changed and processed very easily and inexpensively. In addition, since a certain gap L can be secured in portions other than the throttle portion, there is no need to worry about heat conduction from the heating chamber, and the temperature reliability of the motor and the weight sensor can be maintained.

The structure of the motor shaft penetrating portion allows the motor mounting plate to have a function of sufficiently attenuating high-frequency electromagnetic waves from the heating chamber. In addition, by arranging small protrusions on the outer peripheral portion of the conical base at regular intervals to secure a gap, the temperature rise can be suppressed within the standard.

According to the above-mentioned invention, it is not necessary to mount a new component in the gap between the motor mounting plate and the motor, and the above-mentioned problem can be solved with a simple structure while maintaining the number of components.

[0018]

An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a main part of a high-frequency heating apparatus according to Embodiment 1 of the present invention. FIG. 2 shows the first embodiment.
It is sectional drawing of the high frequency heating device of FIG. FIG. 3 shows the first embodiment.
3A and 3B are a front view and a sectional view of a motor mounting plate of the high-frequency heating device of FIG. FIG. 4 is a perspective view of a weight sensor motor of the high-frequency heating device according to the first embodiment.

1 to 4, reference numeral 7 denotes a heating chamber for taking in and out the object to be heated 12, 8 denotes a heating means attached to the bottom plate of the heating chamber 7, 9 denotes a fixing bracket for fixing the heating means 8, and 10 denotes a fixing bracket. The motor mounting plate fastened to 9, 10a is a motor shaft penetrating portion provided on the motor mounting plate 10, and 10b is a protrusion (contact) disposed at a constant interval on the base portion 10c of the conical constricted portion forming the motor shaft penetrating portion 10a. Member). 11 is a motor mounting plate 1 via a motor 11a.
The motor shaft 11b is regulated by a resin ring 11c and a side pressure spring 11d by a weight sensor fastened to zero.

The weight sensor 11 measures the initial weight of the object to be heated 12 or the weight after being heated by the heating means 8 or a change in the weight.
It provides information for determining the optimal heating time or heating amount. It is considered that the sensor accuracy of the weight sensor 11 easily depends on the shape of the object to be heated 12 and the position on which the object 12 is placed. It has a structure that suppresses and ensures sensor accuracy. The motor 11a has a configuration in which a resin ring 11c and a side pressure spring 11d are attached to a motor shaft 11b in order to ensure sensor accuracy. Therefore, in this embodiment, if the resin ring 11c and the side pressure spring 11d are not provided, the motor shaft 11
If an eccentric load is applied to b, the pressure applied to the weight sensor 11 will be eccentric, and the correct weight cannot be detected. Therefore, even when the object 12 to be heated is placed at a position deviated from the center, a change in the load transmitted to the weight sensor 11 via the motor shaft 11a is changed by the resin ring 11c and the side pressure spring 11d.
This allows the sensor accuracy to be kept to a minimum.

In the motor mounting plate 10 of the first embodiment, in order to mount the motor 11a incorporating the weight sensor 11, the resin ring 11 mounted on the motor shaft 11b is mounted.
In order to prevent the side pressure spring 11d from contacting and interfering with the motor shaft penetrating portion 10a, a conical throttle portion 10c is provided in the motor shaft penetrating portion 10a for relief. It is known that the inner diameter of the motor shaft penetrating portion 10a greatly affects the leakage of electromagnetic waves from the bottom of the heating chamber 7 and the leakage of hot air, and also the heating of the object to be heated 12 and the like in the heating chamber 7 by water spillage. There is also a demand for a water-resistant structure for preventing insulation deterioration of the charged part such as the means 8 and the motor 11a. Also,
The motor mounting plate 10 and the motor 11a are designed to have a certain gap L except for the screw fastening portion in order to minimize the temperature rise due to heat conduction from the heating chamber 7 at the contact surface between the motor mounting plate 10 and the motor 11a.

Projection 10b arranged on motor mounting plate 10
(Referred to as a contact member) is very close to or in contact with the motor 11a.
The high frequency electromagnetic wave leaked from a is greatly attenuated. That is, the high-frequency electromagnetic waves leaked from the motor shaft penetrating portion 10a via the side pressure springs 11d are grounded (contacted) to the motor mounting plate 10 by the projections 10b (referred to as contact members) arranged on the motor mounting plate 10, thereby providing the inverter. It is possible to prevent a situation in which an electronic circuit or the like of the control unit is affected to cause a malfunction or destruction of an electronic component, and to have a performance satisfying a standard of electromagnetic wave leakage.

As described above, according to the present embodiment, by providing projections at regular intervals in the motor shaft penetrating portion, there is no need to mount new components in the gap between the motor mounting plate and the motor, and the heat insulation is provided. Can be provided while suppressing the leakage of high-frequency electromagnetic waves while ensuring the gap between the two.

(Embodiment 2) FIG. 5 is a front view and a sectional view of a motor mounting plate of a high-frequency heating device according to Embodiment 2 of the present invention.

The components having the same reference numerals as in the first embodiment have the same configuration.

In FIG. 5, reference numeral 10d denotes a bead portion (referred to as a contact member) which is arranged at regular intervals on the base portion of the conical constriction portion 10c forming the motor shaft penetration portion 10a. A bead portion 10d (referred to as a contact member) disposed on the motor mounting plate 10 can reliably contact the motor 11a,
In that part, high-frequency electromagnetic waves leaked from the motor shaft penetration portion 10a are greatly attenuated, which can prevent the electronic circuits of the inverter control unit from being affected, leading to malfunctions and destruction of electronic components, and to prevent electromagnetic wave leakage. Which also satisfies the following.

In the motor mounting plate 10 according to the second embodiment, it is not necessary to pay much attention to heat insulation of the gap between the motor mounting plate 10 and the motor 11a. 10 and motor 1
The ratio of the bead portion 10d (referred to as a contact member) is increased so that the contact area on the motor mounting plate 10 side can be as large as possible so that the ground (contact) with 1a can be sufficiently obtained. It was done.
By providing a fixed width bead (contact member) in the motor shaft penetration, there is no need to install new parts in the gap between the motor mounting plate and the motor, while securing the gap for heat insulation, In most cases, the motor mounting plate and the motor can be reliably brought into contact with each other, and in particular, it is possible to provide a configuration in which the function of suppressing high frequency electromagnetic wave leakage is enhanced. That is,
In the high-frequency heating apparatus having the same heating chamber configuration and dimensions as in the first embodiment, but having an increased output function of high-frequency electromagnetic waves, the function of suppressing high-frequency electromagnetic wave leakage can be more exerted.

(Embodiment 3) FIG. 6 is a front view and a sectional view showing an assembly of a motor mounting plate and a weight sensor motor of a high-frequency heating device according to a third embodiment of the present invention, and FIG. It is AA line sectional drawing of a heating apparatus.

The components having the same reference numerals as in the first embodiment have the same configuration.

6 and 7, reference numeral 10e denotes a base portion 10 of the conical constricted portion forming the motor shaft penetrating portion 10a.
c is a throttle portion (referred to as a contact member) provided at a portion orthogonal to the side pressure spring 11d of the motor 11a.

In the motor mounting plate 10 of the third embodiment, in order to mount the motor 11a incorporating the weight sensor 11, the resin ring 11 mounted on the motor shaft 11b is used.
In order to prevent the side pressure spring 11d from contacting the motor shaft penetrating portion 10a, the motor shaft penetrating portion 10a is provided with a conical constricted portion 10c for relief. It is known that the inner diameter of the motor shaft penetrating portion 10a greatly affects the leakage of electromagnetic waves from the bottom of the heating chamber 7 and the leakage of hot air, and also the heating of the object to be heated 12 and the like in the heating chamber 7 by water spillage. There is also a demand for a water-resistant structure for preventing insulation deterioration of the charged part such as the means 8 and the motor 11a. Further, the motor mounting plate 10 and the motor 11a are designed to have a certain gap L except for the screw fastening portion in order to minimize the temperature rise due to heat conduction from the heating chamber 7 at the contact surface between the motor mounting plate 10 and the motor 11a. I have.

The weight sensor 11 measures the initial weight of the object 12 to be heated, or measures the weight after being heated by the heating means 8 or a change in the weight.
It provides information for determining the optimal heating time or heating amount. It is considered that the sensor accuracy of the weight sensor 11 easily depends on the shape of the object to be heated 12 and the position on which the object 12 is placed. It has a structure that suppresses and ensures sensor accuracy. The motor 11a has a configuration in which a resin ring 11c and a side pressure spring 11d are attached to a motor shaft 11b in order to ensure sensor accuracy. In this way, even when the object to be heated 12 is placed at a position deviated from the center, the fluctuation of the load transmitted to the weight sensor 11 via the motor shaft 11c is minimized by the resin ring and the side pressure spring 11b. Sensor accuracy can be ensured.

Here, microscopically, the motor shaft 11
Since it is considered that the tip bent for fixing the side pressure spring 11b attached to c has a particularly strong electric field,
This is because it is considered that the throttle portion 10e (referred to as a contact member) facing the portion can maximize the damping effect.
That is, since it is considered that high-frequency electromagnetic waves are most likely to leak from the gap for heat insulation of the motor mounting plate 10 in the vicinity of the side pressure spring 11b, a narrow portion 10e (referred to as a contact member) is formed in a portion opposed thereto. It is intended to most effectively suppress electromagnetic wave leakage.

With this configuration, the electromagnetic wave swept by the side pressure spring 11b itself is reliably grounded (contacted) from the motor mounting plate 10 to the case of the motor 11a, so that the high-frequency electromagnetic wave leaked from the motor shaft penetration portion 10a at that portion. Greatly attenuating the influence on the electronic circuit of the inverter control unit and the like, thereby preventing malfunctions and destruction of electronic components, and having a performance that satisfies the electromagnetic wave leakage standard.

A throttle portion (referred to as a contact member) is provided in a portion of the motor mounting plate closest to the side pressure spring and in a direction where radiation of high-frequency electromagnetic waves is most likely to be emitted, that is, in a direction orthogonal to the side pressure spring 11d. This makes it possible to most effectively prevent high-frequency electromagnetic wave leakage from the motor shaft penetration portion. In other words, the electronic components of the inverter control unit can be protected from leaked high-frequency electromagnetic waves with a simple aperture shape, and the reliability of the electronic circuits and the like can be sufficiently ensured. As a result, the reliability and safety of the high-frequency heating device can be ensured. Can be improved.

A contact member (for example, a protrusion 10b, a bead portion 10) provided in the motor shaft penetration portion of the motor mounting plate.
d, the constricted portion 10e) does not have to be a product that sticks to these shapes. If the motor 11a can be grounded and has a small heat capacity, it should be formed integrally from the motor mounting plate 10. However, regardless of whether they are formed of separate members, the effects of the present invention can be exerted in any case.

It is needless to say that the contact member may be a contact member having a small heat capacity (low heat conductivity).

Since the contact member needs to be grounded, it is needless to say that the contact member is preferably conductive.

Further, it is needless to say that the contact member is preferably close to or in contact with the motor.

It is needless to say that close proximity can be expected to greatly enhance the electromagnetic wave attenuating effect as long as the distance is from several mm or less to the point of contact.

[0042]

As described above, according to the present invention, it is necessary to mount a new part in the gap between the motor mounting plate and the motor by providing projections at a fixed interval and a simple throttle portion in the motor shaft penetrating portion. Therefore, it is possible to provide a configuration that suppresses electromagnetic wave leakage while securing a gap for heat insulation. In other words, high-frequency electromagnetic waves leaking from the motor shaft penetration part are greatly attenuated in that part, affecting the electronic circuit of the inverter control unit, etc., preventing malfunctions and destruction of electronic components, and preventing high-frequency electromagnetic wave leakage. It is possible to provide an inexpensive and highly reliable structure while ensuring performance that also satisfies the above-mentioned standard.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a high-frequency heating device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the high-frequency heating device.

FIG. 3A is a front view of a motor mounting plate of the high-frequency heating device. FIG. 3B is a cross-sectional view of a motor mounting plate of the high-frequency heating device.

FIG. 4 is a perspective view showing the assembly of a weight sensor motor section of the high-frequency heating device.

5A is a front view of a motor mounting plate of the high-frequency heating device according to the second embodiment of the present invention. FIG. 5B is a cross-sectional view of the motor mounting plate of the high-frequency heating device.

FIG. 6 (a) is a view showing attachment of a weight sensor motor to a motor mounting plate of the high frequency heating device according to the third embodiment of the present invention. (B) Cross-sectional view of the motor mounting plate of the high frequency heating device according to the third embodiment of the present invention.

FIG. 7 is a sectional view taken along the line AA of FIG.

FIG. 8 is a sectional view of a main part of a conventional high-frequency heating device.

FIG. 9 is a cross-sectional view of a conventional high-frequency heating device.

10A is a front view of a motor mounting plate of a conventional high-frequency heating device. FIG. 10B is a cross-sectional view of a motor mounting plate of a conventional high-frequency heating device.

[Explanation of symbols]

 7 Heating Room 8 Heating Means 9 Fixture 10 Motor Mounting Plate 10a Motor Shaft Penetration 10b Projection (Contact Member) 10c Conical Restriction 10d Bead (Contact Member) 10e Restriction (Contact Member) 11a Motor 11d Side Pressure Spring 12 Cover Heated object

Claims (4)

[Claims] 1. A heating chamber for taking in and out an object to be heated, a heating means attached to the bottom plate of the heating chamber, a fixture for fixing the heating means, a motor attachment plate fastened to the fixture, and a motor attachment. A conical constriction is formed in the motor shaft penetration portion of the plate, and a small heat capacity contact is made with or near the motor in the gap between the motor mounting plate and the motor on the outer periphery of the base of the conical constriction. A high-frequency heating device provided with a member. 2. A heating chamber for taking in and out an object to be heated, a heating means attached to the bottom plate of the heating chamber, a fixing fitting for fixing the heating means, a motor mounting plate fastened to the fixing fitting, and the motor mounting. A high-frequency heating device having a configuration in which a conical constriction is formed in a motor shaft penetrating portion of a plate, and a protrusion is provided on an outer periphery of a base portion of the conical constriction, so as to approach or contact the motor. 3. A heating chamber for taking in and out an object to be heated, a heating means mounted on the bottom plate of the heating chamber, a fixture for fixing the heating means, a motor mounting plate fastened to the fixing bracket, and the motor mounting. A high-frequency heating device having a configuration in which a conical constriction is formed in a motor shaft penetrating portion of a plate, a bead portion is provided on an outer periphery of a base portion of the conical constriction, and the motor is brought close to or in contact with the motor. 4. A heating chamber for taking in and out an object to be heated, a heating means mounted on the bottom plate of the heating chamber, a fixing fitting for fixing the heating means, a motor mounting plate fastened to the fixing fitting, and the motor mounting. A conical throttle portion is formed in the motor shaft penetration portion of the plate, and a throttle portion is provided at a portion orthogonal to the side pressure spring of the motor at a base portion of the conical throttle portion, and is configured to approach or contact the motor. High frequency heating device.