JP2001171335A - Heating device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device for a vehicle allowing reduction of a current carrying number to eliminate waste of electric power and improve durability of electrical components concerning heating by turning on an electric heater only when the heating is required. SOLUTION: This heating device has a heating performance control means 5 controlling air heating performance in a heating heat exchanger 2, and a maximum heating performance detection means 6 detecting that the air heating performance in the heating performance control means 5 is substantially maximum. The electric heater 3 is turned on only when the maximum heating performance detection means 6 detects the maximum heating performance. Because the electric heater 3 is turned on only under a maximum heating condition, the current carrying number is reduced to eliminate the waste of the electric power and to improve the durability of the electric components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for a vehicle, and more particularly to a heating device for a vehicle that uses both heat of an engine cooling water and heat of an electric heater.

[0002]

2. Description of the Related Art Conventionally, in a vehicle equipped with an engine, such as an automobile, a heat source of warm air used for heating the interior of the vehicle or defrosting a window glass such as a front window is used as cooling water for cooling the engine. Depends. That is, in such a vehicle, warm air is obtained by guiding the cooling water of the engine to the heater core, which is a heating heat exchanger, by piping, and passing the air generated by the blower through the heater core.

However, in such a vehicle heating system, the temperature of the cooling water does not increase immediately after the engine is started. Therefore, the interior of the vehicle cannot be heated until the temperature of the engine increases and the temperature of the cooling water increases. Had to endure.

In order to solve such a problem, an electric heater is installed in a ventilation passage of a heating device, or an electric heater is incorporated in a heater core. Hot air is obtained, and when the temperature of the cooling water rises, the power to the electric heater is turned off, and a heating device for a vehicle that obtains hot air using the heater core as a heat source, or an electric heater in a circulation passage of the cooling water is provided. A heating device for a vehicle has been proposed in which the electric heater is energized when the temperature of the cooling water is low to increase the temperature of the cooling water to obtain warm air from the heater core.

Japanese Utility Model Laid-Open Publication No. 56-131207 discloses that an electric heater is provided only when the outside water temperature is lower than a predetermined temperature, the engine water temperature is lower than the predetermined temperature, and the power supply capacity of the battery is sufficient. There has been proposed an air-conditioning control device for a vehicle configured to operate a vehicle.

[0006]

However, in a conventional vehicle heating system in which an electric heater is used in combination with a cooling water heating system, the electric heater is energized only when the temperature of the cooling water is not increased, for example, after the engine is started. Since the heater core and the cooling water are simply heated to obtain warm air, the electric heater is energized regardless of whether the occupant needs heating.

As a result of studying the frequency of energization of the electric heater, the inventor has found that the power is frequently energized under the conditions of the above-described conventional apparatus, and wasteful power is wasted due to unnecessary heating. It was found that a useless load was applied to the heater and the like to deteriorate the durability.

Particularly, the relay of the electric heater is frequently turned on.
By repeatedly performing the OFF operation, it is predicted that the number of operations exceeds the guaranteed number of times, which may cause a failure or that the heating performance cannot be ensured due to a defective contact.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and reduces the number of times of energization by energizing an electric heater only when heating is necessary, thereby eliminating waste of electric power and heating. It is an object of the present invention to provide a heating device for a vehicle that can improve the durability of electric components related to the heating device.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, a heating capacity adjusting means (5) for adjusting an air heating capacity in a heating heat exchanger (2).
And a maximum heating capacity detecting means (6) for detecting that the air heating capacity in the heating capacity adjusting means (5) is substantially maximum, and the maximum heating capacity detecting means (6).
And the electric heater (3) is energized only when the maximum heating capacity is detected.

The heating capacity adjusting means is, for example, a temperature control door. In the case of a manual air conditioner, the maximum heating capacity detecting means is, for example, a micro-controller provided at a max hot side rotation end of a temperature control door drive link of an air conditioning case. The switch is a switch, and in the case of an automatic air conditioner, for example, is a hot air mixing ratio signal from a temperature control door output from an air conditioner control device.

When the maximum heating capacity is detected,
If the setting on the air conditioner operation panel provided on the instrument panel in the cabin is manual, it is at the max hot position, or if auto, the setting temperature is higher than the current cabin temperature and the difference is large. Thus, the electric heater is energized only when it is determined that the occupant is requesting rapid heating.

[0013] Thus, since the energization of the electric heater is performed only during the maximum heating condition, the number of times of energization is reduced, so that waste of electric power is eliminated, and the durability of electric components related to heating, such as an alternator, a battery, an electric heater, and a relay, is reduced. Performance can be improved.

According to a second aspect of the present invention, there is provided an outside air temperature detecting means (7) for detecting an outside air temperature, when the outside air temperature detected by the outside air temperature detecting means (7) is lower than a predetermined temperature, and The electric heater (3) is energized only when the maximum heating capacity is detected by the maximum heating capacity detection means (7).

The outside air temperature detecting means uses, for example, an intake air temperature sensor of an air flow meter attached to an engine as an outside air temperature sensor. This is because the electric heater is energized only when it is determined that the occupant is requesting rapid heating in winter or the like when the outside air temperature is low. Rapid heating will not be performed until the heater is energized.

As a result, the conditions for energizing the electric heater are further reduced, the number of times of energization is reduced, and waste of power is eliminated.
The durability of electrical components can be improved.

According to a third aspect of the present invention, a glow plug is used for the electric heater (3). By attaching the glow plug to the cylinder head of the engine, a structure for heating the cooling water can be easily made.

[0018]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram showing a circulation circuit of cooling water and the inside of an air conditioning case according to an embodiment of the present invention, and FIG. 2 is a control circuit diagram according to an embodiment of the present invention.

Reference numeral 8 denotes a water-cooled internal combustion engine (hereinafter, engine) for a vehicle device. R is a cooling water circuit (heat source fluid circuit) for cooling the engine 8. Reference numeral 8a denotes a mechanical pump that is built into the engine 8 and circulates engine cooling water (hereinafter, cooling water) through the cooling water circuit R by obtaining driving force from the engine. The mechanical pump 8a is driven in conjunction with the driving of the engine 8.

Reference numeral 9 denotes a radiator for cooling the cooling water by exchanging heat between the cooling water and the air outside the vehicle compartment, and reference numeral 10 denotes a bypass circuit that bypasses the radiator 9 and through which the cooling water flows. 1
Reference numeral 1 denotes a well-known thermostat that switches between a case in which the cooling water flowing out of the engine 8 flows into the radiator 9 and a case in which the cooling water flows into the bypass circuit 10. The thermostat 11 has a radiator 9 according to the temperature of the cooling water flowing in the thermostat 11. And the bypass circuit 10.

Reference numeral 3 denotes a glow plug, which is attached to a cylinder head of the engine 8 and is provided so as to protrude a heat generating portion into a cooling water circuit R flowing through the engine 8 to heat the cooling water.

Reference numeral 2 denotes a heating heat exchanger (hereinafter, heater core) provided in the cooling water circuit R and through which the cooling water flows. The heater core 2 is arranged in an air-conditioning case 1 that forms an air passage into a vehicle interior.

A blower 12 blows air. The blower 12 generates an airflow in the air-conditioning case 1 toward the passenger compartment. The blower 12 is an air conditioning case 1
A blower for generating an airflow passing through the heater core 2 is formed therein. The air blown by the blower 12 is heated by the heater core 2 and then blown out into the vehicle interior. The operating state of the blower 12 is controlled by the air conditioner control device 6b.

In the air conditioning case 1, a cooling heat exchanger 13 for cooling air is disposed upstream of the heater core 2 in the air. The cooling heat exchanger 13 constitutes a refrigerant evaporator (hereinafter, an evaporator) of a known refrigeration cycle mounted on a vehicle.

The refrigeration cycle will be briefly described. A compressor for compressing and discharging refrigerant, a condenser for condensing refrigerant compressed by this compressor, a decompression device for decompressing refrigerant condensed by this condenser, It has the evaporator 13 for evaporating and evaporating the refrigerant decompressed by the device. Note that the compressor is driven by the engine 8.

In the air conditioning case 1, the evaporator 1
A bypass passage 14 is formed in which the air passing through 3 bypasses the heater core 2. Air conditioning case 1
Inside, there is provided a temperature control door (heating capacity adjusting means) 5 for adjusting the temperature of the conditioned air by adjusting the amount of air passing through the bypass passage 14 and the amount of air passing through the heater core 2.

In the case of a manual air conditioner, a cable from an air conditioner operation panel in the vehicle compartment is used to drive the temperature control door 5 via a temperature control door drive link attached to the outside of the air conditioner case 1. In the case of an air conditioner, the air conditioner is driven by a temperature control door drive servomotor attached to the outside of the air conditioner case 1 according to a signal from the air conditioner control device 6b according to a setting on an air conditioner operation panel.

Next, the control device 15 for controlling the above-described vehicle heating device will be described. The control device 15 supplies the electric power from the alternator 4 or the battery 16 to the O
The power supply to the electric heater 3 is controlled by N-OFF, and is actually incorporated in the engine control device.

In practice, three electric heaters 3 are used, and the number of electric heaters is finely switched according to the power supply capacity and the temperature of the cooling water.
Detailed control will be omitted only for -OFF.

The input signals to the control device 15 include a signal indicating the power supply capability of the alternator 4 and the engine 8
Are the cooling water temperature from the water temperature sensor 18 and the outside air temperature when the intake air temperature sensor of the air flow meter attached to the engine 8 is used as the outside air temperature sensor (outside air temperature detecting means) 7.

Here, the power supply capability of the alternator 4 is defined as a condition in which the alternator 4 has a surplus power generation capacity, a condition in which the battery 16 has a surplus charge state, or a charge / discharge balance between the alternator 4 and an electric load connected thereto. Refers to situations where there is room to spare.

In addition to the above-mentioned conventional input signal, in the case of a manual air conditioner, a micro switch 6a is provided at the max hot side rotating end of the temperature control door drive link as the maximum heating capacity detecting means 6, In the case of an air conditioner, a hot air mixing ratio signal at the temperature control door 5 output from the air conditioner control device 6b is used. This may be a method of detecting the position of the temperature control door using a well-known potentiometer or the like.

The microswitch 6a is a well-known ON-OFF switch having a fixed contact and a movable contact.
An ON signal is generated when the temperature control door has an opening degree (max hot) that allows all the air that has passed through the evaporator 13 to flow to the heater core 2.

The air conditioner control device 6b calculates a target blow-out temperature in consideration of various air-conditioning environment factors based on settings on the air-conditioner operation panel, and, based on the calculated target outlet temperature, determines a stop position (opening degree) of the temperature control door 5. ) And the amount of air blown by the blower 12 is controlled.

Next, a description will be given of the energization control of the electric heater according to the embodiment of the present invention.

FIG. 3 is a flowchart showing the control contents. First, in step S1, it is determined whether or not the outside air temperature is equal to or less than a predetermined value. Specifically, the process proceeds to step S2 or S3 as a condition for using the electric heater 3 when the outside air temperature is 10 ° C. or less, and proceeds to step S7 when the outside air temperature exceeds 10 ° C., and the electric heater 3 is not used.

Next, it is determined whether or not the maximum heating capacity detecting means 6 detects the maximum heating capacity. Specifically, step S2 is for a manual air conditioner, and it is determined whether or not the micro switch 6a for detecting that the temperature control door 5 is at the maximum hot position is ON.

Step S3 is for an automatic air conditioner.
This is whether or not the hot air mixing ratio SW at the temperature control door 5 from the air conditioner control device 6b is 90% or more. That is, 90% or more of the air that has passed through the evaporator 13 is supplied to the heater core 2.
It is determined whether or not the opening degree (so-called “max hot state”) is such as to flow through.

The process proceeds to step S4 on condition that the detection of the max hot state in step S2 or step S3 uses the electric heater 3, and otherwise proceeds to step S7 where the electric heater 3 is not used.

Next, in step S4, it is determined whether or not the alternator has a power supply capability. The process proceeds to step S5 assuming that the electric heater 3 has the power supply capability, and if not, the process proceeds to step S7 and the electric heater 3 is not used.

Finally, in step S5, it is determined whether the cooling water temperature is equal to or lower than a predetermined value. Specifically, the cooling water temperature is 65 ° C.
The following cases are used as conditions for using the electric heater 3 in step S
Proceeding to step S6, if the outside air temperature exceeds 65 ° C., step S7
And the electric heater 3 is not used.

As described above, the electric heater is turned on only when it is determined that heating is required and when it is determined that the occupant is requesting rapid heating as shown in steps S2 and S3. As a result, the number of times of energization is reduced, power is not wasted, and the durability of electric components related to heating, such as an alternator, a battery, an electric heater, and a relay, can be improved.

In the above-described embodiment, the air-mixing type in which the mixing ratio of the cold air and the hot air is adjusted is described as the vehicle heating device. However, in the present invention, the flow rate of the hot water flowing through the heater core 2 is adjusted. The present invention may be applied to a so-called reheat type heating device in which the temperature of the conditioned air is adjusted by using.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a cooling water circulation circuit and the inside of an air conditioning case according to an embodiment of the present invention.

FIG. 2 is a control circuit diagram according to an embodiment of the present invention.

FIG. 3 is a flowchart showing the control of energization of the electric heater in one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-conditioning case 2 Heater core (heating heat exchanger) 3 Electric heater 4 Alternator 5 Temperature control door (heating capacity adjustment means) 6 Maximum heating capacity detection means 7 Outside air temperature sensor (outside air temperature detection means)

Claims (3)

[Claims] 1. An air conditioning case (1) forming an air passage into a vehicle interior, a heating heat exchanger (2) provided in the air conditioning case (1) for heating air, and a heating heat exchange An electric heater (3) for assisting the air heating capability of the heater (2), the electric heater (3) having the power supply capability of the alternator (4) and the engine cooling water temperature being equal to or lower than a predetermined temperature. A heating capacity adjusting means (5) for adjusting an air heating capacity in the heating heat exchanger (2); and an air heating capacity in the heating capacity adjusting means (5) substantially. Maximum heating capacity detecting means (6) for detecting the maximum heating capacity, and energizing the electric heater (3) only when the maximum heating capacity detecting means (6) detects the maximum heating capacity. Vehicle characterized by Heating. 2. An outside air temperature detecting means (7) for detecting an outside air temperature, wherein said outside air temperature detected by said outside air temperature detecting means (7) is lower than a predetermined temperature, and said maximum heating capacity detecting means. The vehicle heating device according to claim 1, wherein the electric heater (3) is energized only when the maximum heating capacity is detected in (7). 3. The vehicle heating device according to claim 1, wherein a glow plug is used for the electric heater.