JPS5931443Y2 - Automotive heating system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heating device for an automobile that has a heating heater core using engine cooling water as a heat source and a heating resistor that generates heat when energized in a ventilation duct.

As shown in Japanese Utility Model Application Publication No. 47-1536, a conventional device of this type includes a heater core that uses engine cooling water as a heat source, a heat generating resistor that generates heat when energized, and is installed in a ventilation duct. The configuration is such that energization to the heating resistor is controlled by a blower speed selector switch and a water temperature switch that detects the engine coolant temperature.

However, in the above-mentioned conventional device, the blower speed set by operating the blower speed selector switch is the same for hot water heating using the heating heater core and hot water heating using the heat generating resistor. Problems such as the following may occur.

In other words, in the case of electric heating, although the amount of heat generated is limited by the capacity of the vehicle's battery, the blower speed is the same as in the case of hot water heating, so the amount of air blown is excessive.
As a result, there is a problem that the temperature rise of the blown air into the vehicle interior is small, resulting in a lack of sense of temperature.

The present invention was developed in view of the above points, and when performing electric heating by energizing the heating resistor, it is possible to reduce the speed of the blower even more than when performing hot water heating using the heater core. The purpose is to rapidly generate a small amount of air using a heating resistor to improve the feeling of heating.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows a first embodiment of the present invention, in which reference numeral 1 denotes a ventilation duct, which has an air intake port 2 at one end and an air outlet 3 into the passenger compartment at the other end.

The air intake port 2 is configured to suck air inside the vehicle or outside the vehicle via an outside/outside air switching box (not shown).
In addition, the air outlet 3 includes a lower air outlet for heating, an upper air outlet for ventilation and cooling, which are opened and closed by a mode switching damper (not shown).
A defroster outlet, etc. is provided.

A heater core 4 heats air using the cooling water of an automobile engine as a heat source, and is installed in the ventilation duct 1, and a bypass passage 5 is formed on the side of the heater core.
The ratio of the amount of air passing through the heater core 4 is adjusted by a temperature control damper 6.

7 is installed on the upstream side of the ventilation duct 1, and
This is a blower that blows air into the room, and is driven by a motor 8.

Reference numeral 9 denotes a heating resistor installed downstream of the heater core 4 in the ventilation duct 1, and in this example, a general nichrome wire heater is used.

10 is a resistor unit, in which resistors 12, 13 for speed control of the blower 7 and auxiliary resistor 14 for breeze are arranged on one common insulating substrate 11, and these are inserted into the ventilation duct 1. , forced air cooling is used.

Resistor 12 is for medium speed, and resistor 13 is for low speed.

Reference numeral 15 denotes a blower speed selector switch manually operated by the user, which is installed on or near the instrument panel of the automobile, and 16 is a movable contact thereof.

17a+17b are fixed contacts for light wind, 18 is a fixed contact for low speed, 19 is a fixed contact for medium speed, and 20 is a fixed contact for high speed.

21 is a breeze relay, which has a coil 21a and a normally open contact 21b.
It becomes more.

22 is a power source battery for the automobile. Next, the operation of the above configuration will be explained.

When an automobile engine is restarted after being stopped for a long time in winter, the engine cooling water has already cooled down to the same temperature as the outside air temperature, so the hot water heating effect by the heater core 4 cannot be obtained immediately after the engine is started.

Therefore, in the device of the present invention, in such a case, the blower speed selector switch 15 is placed in the breeze position, that is, the movable contact 16 is placed in the solid line position shown in the figure, and the movable contact 16 and the fixed contacts 1γ & 17b are connected. .

As a result, the relay 21 is energized through the contacts 16 and 17a, and its normally open contact 21b is closed, so that the heating resistor 9 is energized and the resistor 9 immediately starts generating heat.

On the other hand, the contact 16° 17b and the breeze auxiliary resistor 1
Electricity is supplied to the drive motor 8 of the blower γ through the motor 4.

Here, the auxiliary resistor 14 is the speed control resistor 13 for low speed.
Since the resistance is set to have a sufficiently large resistance value compared to the resistor 13, the blower 1 rotates at a speed lower than the low speed caused by the resistor 13, that is, at a slight wind speed.

As a result, the air volume at this time is the air volume at low speed (generally 1
(about 50 to 170 rr/h), the air flow is more sufficient (for example, 50 to 100 rr/h).

Therefore, even if the amount of heat generated by the heat generating resistor 90 is limited by the capacity of the battery 22, the blown air can be heated to a sufficiently high temperature from the initial stage of energization, and therefore the vehicle interior can be quickly and efficiently heated.

When the warm-up of the engine is finished and the engine coolant temperature rises to a temperature that allows heating, the movable contact 16 of the switch 15 is placed in any of the positions 18, 19, 20, and the relay is activated. 21 is cut off, and the heating resistor 9 is cut off, and the contacts 18, 19,
20 to energize the blower motor 8.

As a result, the blower 7 rotates at low, medium, and high speeds set by the switch 15, and the blown air is heated by the heater core 4 to heat the interior of the vehicle.

FIG. 2 shows a second embodiment of the present invention, in which the breeze auxiliary resistor 14 is separated from the resistor unit 10 and installed on an insulating substrate 23 common to the heating resistor 9. ，
14 as one unit 24, and the ventilation duct 1
It was installed inside.

Other points are the same as the first embodiment. Note that the blower motor 8 has a low rotational speed at startup (if this occurs, it may be difficult to start the motor 8), so the startup of the motor 8 should be set to a high speed when the breeze is set (when the heating resistor 9 is energized). This may be easily accomplished by rotation, and after the motor 8 has started once, the motor rotation may be reduced to a breeze speed.

The third embodiment shown in FIG. 3 is an example for improving the motor startability, and uses a positive characteristic thermistor (PTC thermistor) 25 whose resistance value rapidly increases at a predetermined temperature. It is installed upstream of the heater core 4 and heating resistor 9 in the ventilation duct 1, and a normally open contact 21c is added to the relay 21, and when setting a breeze, this normally open contact 2
By closing 1c, the positive temperature coefficient thermistor 25 is connected in parallel to the blower motor 8.

In this third embodiment, the resistance value of the auxiliary resistor 14 is
．． This is smaller than that of the second embodiment.

With this configuration, the positive temperature coefficient thermistor 25 is not forcedly cooled by the blower 1 before the motor 8 is started.
The temperature rises due to self-heating, and its resistance value increases rapidly.
The voltage applied to the motor 8 becomes high.

As a result, the motor 8 can be easily started at high rotation speed.

Once the motor 8 is started, it is forcedly cooled by the positive temperature coefficient thermistor 25 or the blower γ, its temperature drops, and the resistance value decreases significantly, so the voltage applied to the motor 8 also drops, and the The rotation speed decreases to the desired breeze speed.

Furthermore, in all of the embodiments described above, the speed of the blower I is changed by manually operating the switch 15, but the temperature of the engine cooling water is detected by a temperature sensing element such as a thermistor. The blower speed may be automatically switched by a switch circuit that opens and closes in response to a signal.

In addition, in the above-described embodiment, the switch 15 is provided with two fixed contacts 17a and 17b for breeze.
7a and 1γb are electrically opened and closed at the same time by the movable contact 16, so both the contacts 17 can be opened and closed as necessary.
It is obvious that a and 17b may be combined into one contact point.

Further, a positive temperature coefficient thermistor having the above-mentioned characteristics can be used as the heating resistor 9, and in this case, there is an advantage that overheating can be prevented by the current limiting action of the positive temperature coefficient thermistor itself.

As detailed above, according to the present invention, when the engine cooling water is low, air heated by the heat generating resistor is introduced into the passenger compartment in a small amount of air, so that the amount of heat generated by the heat generating resistor is reduced. Even if the temperature is set to a low value, the temperature of the air blown into the vehicle interior can be sufficiently raised to quickly and comfortably heat the interior of the vehicle.Furthermore, the amount of heat generated by the heating resistor can be set to a low value, reducing the load on the vehicle battery. As well as being able to
The advantage is that thermal deformation of the resin duct member near the heating resistor can be prevented.

Furthermore, in the present invention, the blower speed changeover switch is independently provided with a fixed contact for light breeze, and when the changeover switch is connected to the position of the fixed contact for breeze, the heating resistor is energized and the blower drive motor is connected to the light breeze. Since the configuration is such that the current is applied through the resistor, the existing blower speed selector switch can be used to control the current to the heat generating resistor and the breeze resistor. The switch mechanism is extremely simple, and in addition, the blower speed selector switch can be moved to the normal operating position (contacts 18, 19, 20).
position), the circuit of the fixed contact for breeze will automatically open and the power to the heating resistor will be cut off, so even after the engine coolant temperature rises, the heating resistor will not be energized. Dogs are effective in preventing the problem of continuing.

[Brief explanation of drawings]

1 to 3 are overall schematic diagrams including the electric circuit of the device of the present invention, FIG. 1 is the first embodiment, and FIG. 2 is the second embodiment.
Embodiment FIG. 3 shows a third embodiment, respectively. 1... Ventilation duct, 2... Air intake port, 3... Air outlet, 4... Heater core,
7...Blower, 8...Drive motor,
9... Heat generating resistor, 12, 13... Speed control resistor, 14... Breeze auxiliary resistor,
15...Blower speed selection switch.

Claims (1)

[Scope of utility model registration request] a ventilation duct having an air inlet at one end and an air outlet into the passenger compartment at the other end; a heating heater core installed in the ventilation duct for heating air using engine cooling water as a heat source; and the ventilation duct. A blower that blows air into the ventilation duct, a speed control resistor connected to the circuit of the drive motor of this blower, a blower speed changeover switch that switches and connects this resistor, and a blower speed switch installed in the ventilation duct that rapidly blows air. a heating resistor for heating, and a breeze auxiliary resistor having a resistance value for rotating the blower at a breeze speed lower than the low speed set by the resistor, and fixed to the changeover switch. Contacts are provided independently, and when the changeover switch is connected to the position of the breeze fixed contact, the heating resistor is energized and the blower drive motor is energized via the breeze resistor. An automotive heating device characterized by: