JPS604409A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To enable to securely remove frost on a windowglass even in a defrosting mode, by raising a minimum air amount level by a predetermined value when it is detected that the defrosting mode is selected. CONSTITUTION:In accordance with the difference between a temperature set by a temperature setter 1 and the interior temperature detected by interior temperature sensor 2, an optimum temperature is calculated by a controller 4, and conduction of a transistor Tr1 is controlled to control a voltage VM impressed on a blower motor 5, thereby regulating the quantity of air blown off, whereby the interior temperature is controlled to the set temperature. When the defrosting mode is selected, a solenoid valve 6 is energized by the controller 4, thereby opening a blow-off port of the defroster. A transistor Tr2 is made to be conductive by setting the potential at a point A to be low, whereby the quantity of an electric current passed to the base of the transistor Tr1 is increased. Accordingly, the voltage VM impressed on the motor 5 is raised to increase the air quantity.

Description

[Detailed Description of the Invention] C) Technical Field The present invention provides a vehicle in which fogging can be reliably removed even in defroster mode in an air conditioner that controls the amount of air blown based on the temperature difference between a set temperature and a vehicle interior temperature. related to air conditioning equipment.

(B) Prior Art Many modern vehicles are equipped with a near conditioner (hereinafter referred to as an "air conditioner") that dehumidifies the interior of the vehicle and controls the temperature to an optimum level. FIG. 1 shows an air volume control circuit of an air conditioner, in which detection from other sensors 3 is performed depending on the temperature difference between the set temperature set by temperature setting device 1 and the cabin temperature detected by room temperature sensor 2. Considering the signal, the controller 4 including a microcomputer calculates the optimum temperature, adjusts the mixing ratio of cold air and hot air, and also controls the transistor Tr1.
The applied voltage V to the proa fan motor 5 by controlling the conduction of
M is controlled to adjust the amount of air blown out and control the temperature inside the vehicle to the set temperature. Specifically, the mode selection lever provided on the air conditioner is operated to select the air outlet located near the instrument panel, the footwell, and the window glass, and the air outlet is selected by operating a separate temperature control lever. Adjust the air temperature. For example, it blows cold air from an instrument outlet selected with the mode selection lever to cool the interior of the vehicle, or blows warm air from an outlet near the window glass to remove frost or fog on the glass. This latter mode is usually referred to as defroster mode.

On the other hand, the air conditioner is equipped with a fan switch.
When this fan switch is switched, the rotational speed of the proa fan motor is switched and the volume of blown air can be adjusted.

In such an air conditioner, in order to perform air conditioning control quickly and accurately, the applied voltage VM of the proafan motor is controlled as shown in Figure 2 according to the temperature difference between the set temperature and the vehicle interior temperature. When this temperature difference falls below a certain value, the voltage applied to the fan motor is lowered to reduce the noise of the fan and motor, and at this time the air volume is also at the lowest level L. It's quite small. As shown in the figure, this air volume control is provided with a hysteresis characteristic in order to avoid the knocking phenomenon of the motor and fan when the air volume increases and decreases.

By the way, when it rains or there are many passengers, use the windshield.

In such cases, the problem is that when the temperature difference between the set temperature and the interior temperature of the vehicle is large, the air volume blown will be at its lowest level, making it impossible to obtain a sufficient fog removal effect. There is.

(c) Object and structure of the invention The present invention has been made in view of the above points, and has a plurality of modes including a defroster mode that blows air onto the window glass of a vehicle, and also has a temperature difference between a set temperature and a temperature inside the vehicle. In an air conditioner that controls the blowout air volume based on the defroster mode, the purpose is to ensure that fogging can be removed even in the defroster mode, and for this purpose, when it is detected that the defroster mode is selected, the minimum air volume level is set to a predetermined value. It is designed to increase the

(b) Examples The present invention will be explained below based on the drawings.

FIG. 3 shows an embodiment of an air volume control circuit for an air conditioner according to the present invention, in which the same reference numerals as in FIG. 1 indicate the same components. In this embodiment, when the occupant operates the mode selection controls to select the defroster mode, the controller 4 including the microcomputer outputs a defroster mode selection signal (3), which energizes the solenoid valve 6 to create negative pressure. acts on the actuator and the defroster air outlet opens. At this time, the potential VA at point A becomes a low potential, so the transistor Tr2 becomes conductive and the current flowing to the base of the transistor Tr1 increases. As a result, the voltage VM applied to the motor 5 increases by this increase, and the air volume increases. This air volume characteristic is shown by a solid line in Figure 4, and when compared with the conventional air volume characteristic shown by a broken line in the same figure, the lowest air volume level L5
is the lowest level L in Figure 2. It can be seen that the number is increasing.

In this way, in defroster mode, the minimum level of air volume that is controlled based on the temperature difference between the set temperature and the cabin temperature is increased, so even if the cabin temperature is close to the set temperature, the air volume is sufficient. Sufficient removal of abrasions is possible.

In the above embodiment, the temperature difference when the air volume blown by the proa fan starts to increase is set to the same value as in the conventional example shown in FIG. 2, but it is of course possible to change the temperature difference.

(e) Effects of the invention (4) As explained below, in the present invention, when the air conditioner enters the defroster mode, the minimum air volume level is increased, so that the temperature inside the vehicle is close to the set temperature. The effect is that sufficient fogging can be removed even when the window glass is clear, and the clear performance of the window glass can always be ensured.

[Brief explanation of the drawing]

Figure 1 shows the air volume control circuit of a conventional air conditioner, and Figure 2 shows the air volume control circuit of a conventional air conditioner.
FIG. 3 is an air volume control circuit of the air conditioner according to the present invention, and FIG. 4 is an air volume control characteristic diagram of the air conditioner shown in FIG. 1-...Temperature setting device 2...Room temperature sensor 3...Sensor 4...Controller 5...Proafan motor 6...Solenoid pulp. Patent applicant: Nichijo Jidosha Co., Ltd. Agent: Patent Attorney Hiroo Suzuki Figure 1 Figure 3

Claims (1)

[Claims] It has multiple modes including a defroster mode that blows air onto the vehicle's window glass, and controls the amount of air blown out based on the temperature difference between the set temperature and the temperature inside the vehicle, and when the temperature difference is less than a predetermined value, the amount of air blown out is set to the minimum. 1. An air conditioner for a vehicle, characterized in that the air conditioner is provided with an air volume level control means for controlling the minimum air volume level to be increased by a predetermined value in the defroster mode.