JP3514530B2 - Automotive windshield defogger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile windshield defrosting device.

[0002]

2. Description of the Related Art Conventionally, the fog that occurs on the windshield of an automobile, for example, the windshield, is detected by a dew condensation sensor provided on the inner surface of the windshield. The DEF mode is switched to and removed by a windshield fog removing device that blows cold air or hot air directly onto the windshield.

As such a windshield defogging device, for example, as disclosed in Japanese Patent Laid-Open No. 174019/1983, a plurality of dew condensation sensors are provided so as to cope with a complicated distribution state of dew condensation. There is. According to this, there is an advantage that the air conditioning can be appropriately performed according to each situation by grasping the distribution state of the dew condensation.

[0004]

However, the conventional windshield fog removal device requires a plurality of dew condensation sensors to detect the windshield fog condition, which is expensive and annoying. Further, there has been a problem that the control of the dew condensation sensor becomes complicated with the increase of the dew condensation sensor.

In view of the above problems, it is an object of the present invention to provide a windshield fog removing device for an automobile, which can appropriately remove fog while suppressing the number of dew condensation sensors.

[0006]

The inventors of the present invention have found that there are three patterns of fogging on the windshield as shown in FIGS. 4 (a) to 4 (c).

That is, FIG. 4A shows a situation in which the entire windshield is fogged. This occurs when the entire outer surface of the windshield is exposed to the outside air and the temperature is uniformly lowered, and when the humidity uniformly rises and reaches the dew point on the entire inner surface of the windshield. This pattern of fogging occurs when the VENT mode or the B / L mode is selected as the air blowing mode.

FIG. 4 (b) shows a situation in which fogging has occurred on the peripheral portion of the windshield. This occurs when the air that circulates near the inner surface of the windshield does not flow smoothly in the peripheral portion, the humidity rises relative to other portions, and the windshield is cooled by the outside air. . This pattern of fogging occurs when the compressor is off and the blow mode is set to the HEAT mode (no blown to the windshield at all).

Further, FIG. 4 (c) shows a situation in which fogging has occurred on the portion of the windshield where the air is blown directly. This occurs when the high-temperature gas flows back immediately after the compressor is turned off, and the dehumidified water becomes water vapor and is blown directly onto the windshield. This pattern of fogging occurs in the DEF mode, the H / D mode, or the HEAT mode (a part of the air is blown directly to the windshield, which is different from the HEAT mode). This is the case when selected.

Therefore, in the present invention, in order to achieve the above-mentioned object in view of the above three fog patterns, in the invention according to claim 1, the outside air sensor for detecting the outside air temperature and the peripheral portion of the inner surface of the windshield are provided. A dew condensation sensor that is provided to detect the degree of haze on the windshield, and during normal air conditioning control, when the temperature detected by the outside air sensor is equal to or higher than the first set temperature, the compressor is turned on while the outside air sensor detects When the detected temperature is lower than the first set temperature, the compressor is turned off, and the air conditioning is performed in the mode that does not blow air to the windshield (VENT mode, B / L mode or HEAT mode that does not blow air directly to the windshield). If there is a dew condensation signal input from the dew sensor, the rotation speed of the blower will be increased and the temperature detected by the outside air sensor will be the first set temperature. If the temperature is higher than the second preset temperature, which is even lower than that, the compressor is turned on. If the temperature detected by the outside air sensor is lower than the second preset temperature, the compressor is turned off and the windshield is blown directly. And an air conditioning control means for switching to an outside air mode for introducing outside air into the vehicle.

According to the second aspect of the present invention, the outside air sensor for detecting the outside air temperature, the dew condensation sensor for detecting the degree of fogging of the windshield, which is arranged at a position where the wind is blown directly on the inner surface of the windshield, and the ordinary air conditioning system. During control, when the temperature detected by the outside air sensor is equal to or higher than the first set temperature, the compressor is turned on, while the temperature detected by the outside air sensor is equal to or higher than the second set temperature lower than the first set temperature, and When the temperature is lower than the first set temperature and the mode is such that the wind is blown directly to the windshield (HEAT mode, DEF mode or H / D mode in which part of the air is blown directly to the windshield), the compressor is turned on. If there is a condensation signal input from the condensation sensor, the rotation speed of the blower is increased, and if the temperature detected by the outside air sensor is equal to or higher than the second set temperature, While the ON state of the compressors,
When the temperature detected by the outside air sensor is lower than the second preset temperature, the compressor is turned off, and the air-conditioning control means is switched to the outside air mode in which the outside air is introduced into the vehicle as well as the ventilation mode in which the air is blown directly to the windshield. It is provided.

According to the third aspect of the present invention, the outside air sensor for detecting the outside air temperature, and the first dew condensation device, which is arranged at the peripheral portion of the inner surface of the windshield and at the position where the air is blown directly, are used to detect the degree of haze of the windshield. During normal air conditioning control with the sensor and the second dew sensor, if the temperature detected by the outside air sensor is equal to or higher than the first set temperature, the compressor is turned on while the temperature detected by the outside air sensor is less than the first set temperature. If it is, the compressor is turned off, the rotation speed of the blower is increased based on the input of the dew condensation signal from one of the dew condensation sensors, and the temperature detected by the outside air sensor is lower than the first set temperature. When the temperature is equal to or higher than the second set temperature, the compressor is turned on, while when the temperature detected by the outside air sensor is lower than the second set temperature, the compressor is turned off. Wherein with switching to air blowing mode to blow directly to the windshield, but provided with air conditioning control means for switching to the outside air mode for introducing outside air into the vehicle, the.

[0013]

In the invention described in claim 1, during normal air conditioning control,
No B / L mode, VENT mode, or HEAT mode is selected, and therefore no wind is blown directly to the windshield. Therefore, if the B / L mode or the VENT mode is selected, the entire surface of the windshield (see FIG. 3A) will be fogged and the HEAT will be lost.
When the mode is selected, air is first generated in the peripheral portion (see FIG. 3B) where it is difficult to circulate smoothly.

Since the dew condensation sensor is provided at the peripheral portion of the windshield, the dew condensation signal is output by detecting the degree of haze of the windshield at the initial stage of generation regardless of which of the above-mentioned blowing modes is selected. . The air conditioning control means receives a dew condensation signal from the dew condensation sensor and starts dehumidification air conditioning control.

In the dehumidifying air-conditioning control, the blow rate is increased by increasing the rotation speed of the blower. When the temperature detected by the outside air sensor is equal to or higher than the second set temperature, the compressor is turned on to start dehumidification by cooling, and dry air is supplied into the vehicle to remove fogging on the windshield.

On the other hand, when the temperature detected by the outside air sensor is lower than the second set temperature, the air blowing mode is switched to the DEF mode to blow air directly to the windshield to turn off the compressor and switch to the outside air introducing mode. Then, a large amount of outside air, which has a lower humidity than the air inside the vehicle, is blown onto the windshield to remove the fogging that has occurred.

According to the second aspect of the present invention, the HEA blows a part of the air directly to the windshield during normal air conditioning control.
If the T mode (different from the HEAT mode in the invention according to claim 1), the DEF mode, or the H / D mode is selected, fogging occurs in a portion of the windshield that is directly blown (FIG. 3). (See (c)). Also, VEN
If the T mode or the B / L mode is selected, the fog occurs on the entire surface of the windshield as described above (Fig. 3).
(See (a)). Since the dew condensation sensor is provided in a portion of the windshield that is blown directly, it detects fog regardless of which of the above blowing modes is selected.

According to the third aspect of the present invention, the first dew condensation sensor and the second dew condensation sensor reliably detect the occurrence of fogging regardless of which blow mode is selected and how the air conditioning condition is. To do.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a schematic view of an air conditioner equipped with a defogging device. Air is blown into the vehicle through an air conditioning unit 1.

In the air conditioning unit 1, from the upstream side,
An inside / outside air switching damper 2, a blower 3, an evaporator 4, an air mix damper 5, and a heater core 6 are provided, and a blower unit 7 is located downstream thereof. The blower unit 7 is rotatably provided with blower outlet switching dampers 8 for opening and closing the blower outlets (HEAT, DEF, VENT) inside the vehicle. In the present embodiment, unlike the second embodiment to be described later, when the HEAT mode is selected, the DEF outlet is completely closed, and the windshield 23 is never blown directly. .

The inside / outside air switching damper 2, the air mix damper 5, and the outlet switching damper 8 are rotated by driving actuators 9, 10, 11 respectively, and the blower 3 is rotated by driving a motor 12. Each of the actuators 9, 10, 11 and the motor 12 is a drive circuit 1
Drive control is performed by 3, 14, 15, and 16, respectively.

A compressor 17 is installed in the evaporator 4.
By driving, the refrigerant circulating in the cooling cycle flows to cool and dehumidify the air passing through the outside.
The compressor 17 energizes the magnet clutch 18
Turns on and off based on demagnetization, and magnet clutch 18
Are excited and demagnetized based on a control signal from the cooler switch circuit 19. A part of the engine cooling water that circulates by driving a water pump (not shown) in the engine 20 flows into the heater core 6 to heat one of the air split by the air mix damper 5. ing.

An outside air sensor 21 is arranged in the front part of the vehicle, an inside air sensor 22 is arranged in the front part of the vehicle, and a dew condensation sensor 24 is arranged on the inner surface of the windshield 23.
The detection signals of 1 and the dew condensation sensor 24 are input to the determination circuits 25 and 26, respectively.

The position where the dew condensation sensor 24 is provided is the inner surface of the windshield 23 and its peripheral portion (see FIG. 3B). The dew condensation sensor 24 is arranged at this position for the following reason. That is, the fogging generated on the windshield 23 during heating is on the inner surface thereof. Moreover, it does not blow air directly to the windshield. Therefore, in the HEAT mode (in this embodiment, the wind is not directly blown to the windshield 23 at all), cloudiness is likely to occur in the peripheral portion where air is difficult to circulate,
In the VENT mode or the B / L mode, it occurs uniformly on the entire surface. Therefore, if the dew condensation sensor 24 is provided at least in the peripheral portion of the windshield 23, the fog can be detected in any of the above cases.

An operation panel 27 is arranged on the front panel in the vehicle, and a temperature setting device 28, a cooler switch 29,
An air flow rate setting device 30, an air blowing mode setting device 31, and an inside / outside air changeover switch 32 are provided respectively.

The inside air sensor 22 and the determination circuits 25 and 2
6, the signals from the setters 28, 30, 31 provided on the operation panel 27, the switches 29, 32, the drive circuits 13, 14, 15, 16 and the cooler switch circuit 19 are input to the air conditioning controller 33, respectively. It has become. The air-conditioning control device 33 controls the drive circuits 13, 14, 15, 16 from the built-in demist control unit 34 based on these input signals.
Also, a control signal is output to each of the cooler switch circuits 19 to perform the fog removal control described below.

In the air conditioner having the above-mentioned structure, the air conditioner controller 33 controls the defrosting of the windshield 23 in accordance with the flowchart shown in FIG.

That is, when the air conditioning switch is turned on,
First, in step S1, it is determined whether the detected temperature (outside air temperature) T _o at the outside air sensor 21 is first set temperature above T _1. The first set temperature T ₁ is set to a temperature (10 ° C. in this embodiment) higher than the temperature (second set temperature T ₂ ) expected to start frost formation on the evaporator 4.

[0030] If the outside air temperature T _o is the first set temperature above T _1, the compressor 17 is turned on in step S2,
If the outside air temperature T _o is _lower than the first set temperature T ₁ , it is turned off in step S3. Then, in step S4, the rotational positions of the inside / outside air switching damper 2 and the air mix damper 5 and the number of rotations of the blower 3 are determined by the outside air sensor 21 and the inside air sensor 2.
2. Based on the input signals from the setters 28, 30, 31 of the operation panel 27 and the switches 29, 32, the control is performed in the same manner as in the conventional case to start the normal air conditioning operation. Also, step S
At 5, a mode (VENT, B / L, HEAT) other than the mode for directly blowing air to the windshield 23 is selected. As a result, the frost generated on the windshield 23 is
Fig. 3 when T or B / L mode is selected
(A), Fig. 3 (b) when the HEAT mode is selected
In any of the cases, the dew condensation sensor 24 can reliably detect.

Next, in step S7, it is determined whether or not the windshield 23 is fogged based on the dew condensation signal from the dew condensation sensor 24. If it has not occurred, steps S1 to S5 are repeated, and if it has occurred, the process proceeds to step S7 to increase the rotation speed of the blower 3 to increase the air flow rate.

Subsequently, in step S8, it is determined whether the temperature T ₀ detected by the outside air sensor 21 is equal to or higher than the second set temperature T ₂ . The second set temperature T ₂ is a temperature at which the evaporator 4 is expected to start frosting (in this embodiment, it is set to −5 ° C.) and is lower than the first set temperature T _1. is there.

When the outside air temperature T ₀ is equal to or higher than the second set temperature T _2, it is determined that the evaporator 4 will not be frosted. Therefore, in step S9, the compressor 17 is turned on to actively dehumidify the vehicle interior humidity. Down to remove the fog on the windshield 23. However, in this case, since the evaporator 4 cools the passing air, the rotation position of the air mix damper 5 is adjusted so that the temperature of the blown air is kept constant so that the temperature inside the vehicle does not drop too much. Is preferred.

When the outside air temperature T _o is lower than the second set temperature T ₂ , frost is formed on the evaporator 4,
Or, since it is determined that the condition is likely to occur,
In step S10, the blowing mode is switched to the DEF mode, and in step S11, the inside / outside air switching damper 2 is rotated to set the outside air introduction mode. As a result, it is possible to prevent the frost from forming on the evaporator 4 and suppress the power consumption of the compressor 17 while directly blowing the outside air, which has a lower humidity than the inside of the vehicle, onto the windshield 23. Effectively removed.

Hereinafter, the steps S6 to S11 are repeated to continue the fog removal control.

As described above, according to the above-described embodiment, since the wind is not directly blown to the windshield 23 in the normal air conditioning control, the fog generated on the windshield 23 is entirely covered in the VENT mode or the B / L mode. It becomes uniform, and the occurrence of this fogging can be always detected by the condensation sensor 24. Particularly, in the HEAT mode, it is difficult for air to circulate on the inner surface of the windshield 23, and fog is generated from the peripheral portion. However, since the dew condensation sensor 24 is provided at that position as described above, the fog is detected at the initial stage. Therefore, it becomes possible to quickly control fogging removal.

Further, the first set temperature T ₁ and the second set temperature T ₂
Since there is a difference between the windshield 2
If there is no fogging on No. 3, it is possible to save energy by positively turning off the compressor 17.

(Second Embodiment) In the second embodiment, the dew condensation sensor 24 is provided on the inner surface of the windshield 23 at a position where the air is blown directly (hereinafter, the dew condensation sensor provided at this position is denoted by reference numeral 24). 'Is attached.). In this case, the air conditioning control is performed according to the flowchart of FIG. The points different from the first embodiment will be described below.

That is, in step S25, the blowing mode is selected as in the first embodiment (see step S5), but the mode to be selected is not limited. However, unlike the first embodiment, when the HEAT mode is selected, part of the air is blown directly to the windshield 23. Then, in step S26, it is determined whether or not the mode in which the wind is directly blown to the windshield 23, that is, D
It is determined whether the EF mode, the H / D mode or the HEAT mode is selected.

[0040] If the blower mode blown directly to the windshield 23 has been selected, the outside air temperature T _o is determined whether a second set temperature T ₂ or higher at step S27. Here, if the outside air temperature T _o is the second set temperature T ₂ above, even if the outside air temperature T _o is less than the first predetermined temperature T _1, by turning on the compressor 17 in step S28,
Dehumidify actively. On the other hand, the outside air temperature T _o is equal smaller than the second set temperature T _2, to maintain the compressor 17 intact.

In step S26, modes other than the mode in which air is blown directly to the windshield 23 (VENT mode, B
If it is determined that the / L mode) is selected, the process directly proceeds to step S29.

As described above, in the second embodiment, when the HEAT mode is selected, a part of the air is blown directly to the windshield 23. Therefore, as in the first embodiment, the windshield 23 is not blown. The air flow is not impaired at the periphery, so that no fog occurs at this periphery.

That is, when the DEF mode, the H / D mode or the HEAT mode is selected, even if the windshield 23 is fogged, it is the position where the air is blown directly on the inner surface. The cloudiness at this position is
When the compressor 17 is turned off, the high temperature gas flows backward and flows into the evaporator 4, the temperature of the evaporator 4 rises, the condensed water evaporates, and the humidity rises. On the other hand, when the VENT mode or the B / L mode is selected, the fog formed on the inner surface of the windshield 23 becomes uniform as in the first embodiment.
Therefore, as described above, only by providing the dew condensation sensor 24 'at the position where the wind is blown directly on the inner surface of the windshield 23, it is possible to reliably detect the occurrence of fogging.

Even if the outside air temperature T _o is _lower than the first set temperature T ₁ , if the mode in which the air is blown directly to the windshield 23 is selected, the outside air temperature T _o is the second set temperature T ₂ or more. As long as that is the case, that is, the compressor 17 is turned on unless the evaporator 4 is frosted, it is possible to suppress the occurrence of fogging while saving energy.

(Third Embodiment) In the third embodiment, both the first dew condensation sensor 24 and the second dew condensation sensor 24 'are provided, and the ventilation mode is not limited by normal air conditioning control. . In this case, the flow chart is as shown in FIG.
Instead of step S5, the ventilation mode may be determined in step S4. When the HEAT mode is selected, the windshield 23 may be partially blown or not blown at all. Good.

As a result, the first dew sensor 24 can detect the fog that occurs when the windshield 23 is not directly blown in the HEAT mode. Further, the DEF mode, the H / D mode, or the HEA in which a part of the air is blown to the windshield 23
The second condensation sensor 24 'can detect the fog in the T mode. Further, the fog in the VENT mode or the B / L mode can be detected by any one of the dew condensation sensors 24 and 24 '.

[0047]

As is apparent from the above description, in the invention according to the first aspect, the air is not blown directly to the windshield during normal air conditioning control. Becomes Therefore, even if the dew condensation sensor provided on the inner surface of the windshield is only one at the peripheral edge, it is possible to reliably detect fogging at the initial stage of occurrence of fog, and it is not necessary to use a plurality of sensors as in the conventional case, and control is simple. And can be manufactured at low cost.

According to the second aspect of the present invention, during normal air conditioning control, part of the air is blown to the windshield in the HEAT mode, and no limitation is made on the wind blowing mode. The cloudiness caused is the position or the whole where the air is blown directly. Since the dew condensation sensor is provided at the position where the windshield is directly blown, the same effect as the invention according to claim 1 can be obtained.

In the inventions according to the third aspect, since the dew condensation sensors are respectively provided at the peripheral portion of the windshield and the position where the air is blown directly, the same effects as those of the inventions according to the both aspects can be obtained. . That is, it is possible to reliably detect fogging of the windshield regardless of the air blowing mode or the air conditioning state, and the control content does not become complicated.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an air conditioner according to this embodiment.

FIG. 2 is a flowchart showing fog removal control according to the present embodiment.

FIG. 3 is a flowchart showing fog removal control according to another embodiment.

FIG. 4 is a front view showing a frosted state of a windshield.

[Explanation of symbols]

3 Blower 17 Compressor 21 Outside air sensor 23 Windshield 24 Condensation sensor 33 Air conditioning controller

Continuation of the front page (56) References Japanese Patent Publication 6-8787 (JP, B2) Japanese Patent Publication 60-21097 (JP, B2) Actual Public 2-13203 (JP, Y2) Actual Public 2-34972 (JP , Y2) Utility model registration 2519427 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60S 1/54 B60H 3/00

Claims (3)

(57) [Claims] 1. An outside air sensor for detecting an outside air temperature, a dew condensation sensor arranged on a peripheral portion of an inner surface of a windshield for detecting a degree of haze of the windshield, and a temperature detected by the outside air sensor during normal air conditioning control. Is the first
When the temperature is equal to or higher than the set temperature, the compressor is turned on, while when the temperature detected by the outside air sensor is lower than the first set temperature, the compressor is turned off and the air conditioning is controlled in a mode in which air is not blown to the windshield. If there is a dew condensation signal input from the dew condensation sensor, the rotation speed of the blower is increased, and if the temperature detected by the outside air sensor is equal to or higher than the second set temperature lower than the first set temperature, the compressor is turned on while the outside air is released. When the temperature detected by the sensor is lower than the second set temperature, the compressor is turned off, and the air is blown directly to the windshield.
An automotive windshield fog removing device comprising: an air-conditioning control means for switching to an outside air mode for introducing outside air into the vehicle. 2. An outside air sensor for detecting the outside air temperature, a dew condensation sensor for detecting the degree of haze of the windshield, which is provided at a position where air is blown directly on the inner surface of the windshield, and an outside air sensor is used during normal air conditioning control. Detected temperature is first
When the temperature is equal to or higher than the preset temperature, the compressor is turned on, while the temperature detected by the outside air sensor is equal to or higher than the second preset temperature lower than the first preset temperature and lower than the first preset temperature, and the windshield is displayed. If it is in the direct air blowing mode, turn on the compressor, increase the rotation speed of the blower if there is a condensation signal input from the condensation sensor, and if the temperature detected by the outside air sensor is above the second set temperature, turn the compressor on. On the other hand, when the temperature detected by the outside air sensor is lower than the second set temperature while turning on, the compressor is turned off, and the mode is switched to the ventilation mode for directly blowing air to the windshield and the outside air mode for introducing the outside air into the vehicle. A windshield fog removing device for an automobile, which is provided with an air conditioning control means. 3. An outside air sensor for detecting an outside air temperature, and a first dew condensation sensor and a second dew condensation sensor which are respectively arranged at a peripheral portion of an inner surface of a windshield and a position where air is directly blown to detect a degree of haze of the windshield. During normal air conditioning control, the temperature detected by the outside air sensor is
When the temperature is equal to or higher than the set temperature, the compressor is turned on, while when the temperature detected by the outside air sensor is lower than the first set temperature, the compressor is turned off and the dew condensation signal from one of the dew condensation sensors is detected. Based on the input
The blower rotation speed is increased and the temperature detected by the outside air sensor is the first
When the temperature is equal to or higher than the second preset temperature lower than the preset temperature, the compressor is turned on, while when the temperature detected by the outside air sensor is lower than the second preset temperature, the compressor is turned off and the air is blown directly to the windshield. A windshield fog removing device for an automobile, comprising: an air-conditioning control unit for switching to an outside air mode for introducing the outside air into the vehicle as well as for switching to a ventilation mode.