JPH0447541Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an electric heating device incorporated in an air conditioning unit.

(b) Prior art An air conditioning unit incorporating an electric heating device consisting of an electric heater for space heating and a device (temperature fuse or thermostat) to protect the heater from overheating was proposed in Japanese Utility Model Publication No. 50-30212. There is.

In the proposed electric heating device, since a plurality of electric heaters always work simultaneously, it is sufficient to simply install the overheat protection device in close proximity to the electric heater, and there is no need to consider the positional relationship with the electric heater too deeply.

(c) Problems to be solved by the invention When multiple electric heaters are energized individually or simultaneously, it is not possible to accurately control the temperature of the heaters by simply placing an overheat protection device close to the electric heaters. However, there were problems that could not be detected.

The present invention provides an electric heating device that solves the above-mentioned problems by selecting the installation position of the electric heater and the installation position of the overheat protection device.

(d) Means for solving the problem The present invention provides a first electric heater that is individually energized in the ventilation passage where air flows from bottom to top, and also energizes the electric heater above the electric heater at the same time. A second electric heater is provided, and an overheat protection device for controlling energization of the first and second electric heaters is provided at a height that exceeds the first electric heater but does not exceed the second electric heater. It is something.

(E) Effect When only the first electric heater is energized and is in heating operation, the fan breaks down and the air stops flowing.
When the air filter at the air suction port becomes clogged and the air volume decreases, the temperature of the heat generated by the first electric heater increases abnormally. This heat is diffused as it rises due to natural convection or airflow, and comes into contact with the overheat protection device, so that the protection device operates to stop the energization of the first electric heater.

Also, when the first and second electric heaters are energized at the same time and are in heating operation, if the heat generation temperature of the electric heaters rises abnormally due to a fan failure or air filter clogging, the first electric heater will emit a The heat rises and diffuses due to natural convection and air currents and comes into contact with the overheat protection device, and at the same time, the heat emitted from the second electric heater warms the overheat protection device by radiation, so this protection device 2
Both electric heaters work by feeling the heat at the same time, and both electric heaters are turned off.

(F) Embodiment Figure 1 is a perspective view of an air conditioning unit showing a part of its internal structure, showing a unit body 1 whose rear half is embedded in the wall of a house, and a decorative panel 3 that closes a front opening 2 of this body. The air conditioning unit is comprised of these.

Reference numeral 4 denotes a partition plate that partitions the inside of the unit body 1 into an indoor chamber 5 on the front side and an outdoor chamber 6 on the rear side.
A first 2KW electric heater 10, a second 1.5KW electric heater 11, and a third 1.5KW electric heater 12 are supported by a plate fin type evaporator 7, a cross flow fan 8, and support plates 9a, 9b, and 9c. The outdoor chamber 6 has a compressor 13, a plate fin condenser 14, and a fan casing 1.
5 and a propeller fan 16 are built in. The indoor air is supplied to the intake grill 17 of the decorative panel 3.
After passing through the air filter 18, evaporator 7, and electric heaters 12, 10, and 11 in sequence, the crossflow fan 8 sends out the air from the outlet grille 19 of the decorative panel 3 into the room, while the outdoor air is The air is sucked in from the grills 20 on both sides, blown to the condenser 14 by the propeller fan 16, and discharged outside from the central grill (not shown) on the back.Indoor air is cooled by the evaporator 7 during cooling, and by the electric heater during heating. Indoor air is heated at 10, 11, and 12.

Reference numeral 21 denotes a through hole formed by inwardly recessing the center of the lower edge 22 of the unit main body 1 and between it and the decorative panel 3. A portion of the indoor air is sucked in through the through hole 21 and is discharged from the intake grill 17. It is designed to merge with the intake air of

23 is located on the right side of the indoor chamber 5, and the unit main body 1 is positioned so that the front plate 24 faces the front opening 2.
This is an electrical control box built into the unit, which controls the compressor 13, the motor 25 of the cross flow fan 8, the motor 26 of the propeller fan 16, and the electric heaters 10, 11, 1.
Electrical components 27 for controlling the operation of 2 are housed therein.

28 is a power supply connection chamber formed by recessing the corner portion facing the front through-hole 21 of the electrical equipment control box 23;
A power cord 9 has a primary connector 30 at one end and a plug 31 at the other end, and is led out of the unit main body 1 through the through hole 21. A power cord 32 is connected to the primary connector 30 in the power connection chamber 28. The secondary connector is fixed to a side wall 33 of the power supply connection chamber 28 facing the front through-hole 21 .

34 consists of a temperature fuse 34a and a bimetallic thermostat 34b, and the electric heaters 10, 1
This is an overheat protection device that protects Nos. 1 and 12 from overheating.

FIG. 2 is a perspective view of the overheat protection device 34, and FIG. 3 is a longitudinal cross-sectional view of the overheat protection device 34. Four supports 39a, 39b, 39c, 39 with insulators 38 passing through 37
d, the temperature fuse 34a is attached to the mounting base 36 by tightening the pair of lead wires 40 to the two supports 39a, 39b with nuts 41, and the thermostat 34b is attached to the pair of male terminals 42. The female terminal 43 can be attached to the mounting base 36 by inserting the female terminal 43 and tightening the female terminal 43 to the supports 39c and 39d with nuts 44. In this way, the mounting base 36 to which the temperature fuse 34a and thermostat 34b are attached is attached to the side plate 46 of the indoor air ventilation path 45.
After inserting it into the through hole 47 formed in the hole 47 from the left side in FIG. 53, the installation work of the overheat protection device 34 is completed. Reference numeral 54 designates a side plate of the decorative panel 3 that is attached to the unit main body 1 after this attachment work is completed.

In this way, the overheat protection device 34 and the electric heaters 10, 11, and 12, which are installed side by side in the ventilation passage 45 through which indoor air flows from bottom to top, have the arrangement shown in FIG. 3. That is, electric heater 1
0, 11, and 12, the front sides of the U-shaped heating wires are supported by support plates 9a, 9b, and 9c with their front sides slightly lowered, and the middle first electric heater 10
is individually energized, and the second electric heater 11 in the upper stage is
The first electric heater 10 is energized at the same time, the third electric heater 12 at the lower stage is energized at the same time as the first and second electric heaters 10 and 11, and the overheat protection device 34 is U-shaped. parts 55a, 55b,
55c, and at a height that exceeds the first electric heater 10 and does not exceed the second electric heater 11. Specifically, the thermostat 34b is provided at an intermediate position between the first and second electric heaters 10, 11, and the temperature fuse 34a is located at the same height as the upper half of the second electric heater 11. It is provided at a position that extends somewhat toward the electric heaters 10, 11, and 12 than the thermostat 34b.

FIG. 4 is a wiring diagram of the primary connector 30 with a rated capacity of 30 amperes.
58, and between terminals B and C,
and short-circuit wires 59, 60 across terminals D and E.
is connected. 61 is a 30 ampere outlet.

FIG. 5 is a wiring diagram of the secondary side connector 32, and the terminals A to G of this secondary side connector are connected to the electric heater 10,
11, 12, an operation switch 62, a temperature fuse 34a, a bimetallic thermostat 34b,
and the relay winding 63 and this normally open relay contact piece 63
a, 63b, and 63c as shown in the figure.

The primary side connector 30 and the secondary side connector 32 wired in this way are connected and the operation switch 62 is turned on.
When the power is turned on, the first electric heater 10 and the connection 6
The second and third electric heaters 11 and 12 are energized via the short-circuit wires 59 and 60.

In addition, if the outlet 61 is for 20 amperes, by using the plug 31 that fits the shape of this outlet and removing the shorting wire 60, the first electric heater 10 can be connected to the first electric heater 10 via the connection 64 and the shorting wire 59. The second electric heater 11 is energized.

In addition, if the outlet 61 is for 15 amperes, use the plug 31 that matches the shape of the outlet and remove the shorting wires 59 and 60.
Only the electric heater 10 is energized.

In this way, the electric heaters 10, 1 are energized.
1 and 12 are selected depending on the power supply capacity, and the first, second and third electric heaters 10,
11, 12 or first and second electric heaters 1
If the motor 25 of the cross-flow fan 8 breaks down and the airflow stops, or the air filter 18 becomes clogged and the air volume decreases when the motor 25 of the cross-flow fan 8 breaks down and the airflow rate decreases when the airflow fan 0 and 11 are energized at the same time and are in heating operation, the , the heat generation temperature of the third electric heaters 10, 11, 12 or the first and second electric heaters 10, 11 increases abnormally.
The heat emitted from the U-shaped portions 55a and 55c of the first and third electric heaters 10 and 12 is diffused while rising due to natural convection and air current, and at the same time comes into contact with the overheating protection device 34, 11
The heat emitted from the U-shaped portion 55b warms the overheat protection device 34 by radiation action. In this way, the overheat protection device 34 protects the energized electric heaters 10, 11, 1.
All of the heat from 2 is felt at the same time, and when this heat generation temperature reaches 65°C, which is the set temperature of the thermostat 34b, the thermostat 34b is disconnected and the relay winding 63
is demagnetized, normally open relay contacts 63a, 63
b, 63c open and electric heaters 10, 11, 12
is de-energized.

In the unlikely event that the heat generation temperature of the electric heaters 10, 11, 12 reaches 120°C, which is the set temperature of the temperature fuse 34a, due to a malfunction of the thermostat 34b, the temperature fuse 34a is blown and the electric heaters 10, 1
1 and 12 are de-energized. In this case, since the temperature fuse 34a is shifted from the thermostat 34b, it is quickly warmed by the heat of the first and third electric heaters 10 and 12 that rises due to natural convection or air flow, and at the same time It is heated by the radiant heat of the electric heater 11.

In addition, when only the first electric heater 10 is energized and is in heating operation, if the temperature of the heat generated by this electric heater 10 rises abnormally, this heat rises and spreads due to natural convection or air flow and comes into contact with the first electric heater 10. Therefore, the thermostat 34b is quickly turned off at 65°C, and the temperature fuse 34a is quickly turned off at 120°C.

In the above embodiment, three electric heaters 10, 1
1 and 12, but at least the first and second 2
It is sufficient that the electric heaters 10 and 11 are used, and either one of the temperature fuse 34a and the thermostat 34b may be used as the overheat protection device 34.

Further, the electric heaters 10, 11, and 12 may be switched to change the heating capacity.

(G) Effect of the invention According to the invention, the first electric heater is energized independently, and the second electric heater is energized at the same time as the electric heater.
By selecting the wiring position with the electric heater and the installation position of the overheating protection device that controls the energization of both electric heaters, it is possible to
Even during simultaneous energization, the heat generation temperature of the electric heater can be quickly detected and an abnormal temperature rise within the ventilation path can be reliably prevented.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view showing a part of the internal structure of an air conditioning unit;
2 is a perspective view of the overheat protection device, FIG. 3 is a longitudinal sectional view of the overheat protection device, FIG. 4 is a wiring diagram of the primary connector, and FIG. 5 is a wiring diagram of the secondary connector. 10... First electric heater, 11... Second electric heater, 34... Overheat protection device, 45... Ventilation path.

Claims (1)

[Scope of utility model registration request] A first electric heater that is individually energized is provided in the ventilation passage where wind flows from bottom to top, and a second electric heater that is energized at the same time as this electric heater is provided above this electric heater. An electric heating device characterized in that an overheat protection device for controlling energization of the first and second electric heaters is provided at a height that exceeds the heater and does not exceed the second electric heater.