Automotive air conditioner

• US 4,941,525 A
• Filed: 11/23/1988
• Issued: 07/17/1990
• Est. Priority Date: 01/10/1986
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ito, Toshikazu, Kagohata, Tsuneo
• Primary Examiner(s): Ford, John
• Application Number:
  US07/275,680
• Time in Patent Office: 601 Days
• Field of Search: 165/12, 165/16, 165/42, 165/43, 165/40, 237/12.3 A, 237/12.3 B, 237/2 A, 236/49.3, 236/91 R, 236/91 G
• US Class Current: 165/202
• CPC Class Codes: B60H 1/00814 Control systems or circuits characterised by their output, for controlling particular components of the heating, cooling or ventilating installation
• CPC Class Codes: B60H 1/00864 Ventilators and damper doors

Abstract

An air mixing type automotive air-conditioner is disclosed in which an air fed by a blower is heated to a hot air by a hot water type heater, and a mixture ratio between a cold air flowing through a bypass passage around the heater and the hot air is adjusted by an air mixing door used as an adjustment damper. The air-conditioner comprises an outside temperature sensor for generating a first signal, a room temperature setter for generating a second signal, a room temperature sensor for generating a third signal, a first arithmetic unit for calculating a desired blown air temperature on the basis of the first and second signals, and a second arithmetic unit for calculating and controlling a desired blown air flow on the basis of the second and third signals. The air-conditioner is so controlled as to obtain the blown air temperature most suitable for a thermal load of the air-conditioner.

Claims

1. An air-conditioner mounted on a vehicle comprising:

a blower means for delivering air into a passenger room;

a heater core through which hot water circulates to heat the air from said blower means;

an air mixing door disposed for adjusting a mixture ratio between cold air flowing in a bypass passage bypassing said heater core, and hot air to be directed to said heater core;

an outside temperature sensor for generating a first signal in response to the outside temperature;

a passenger room temperature setter for generating a second signal in response to a set passenger room temperature;

a passenger room temperature sensor for generating a third signal in response to a passenger room temperature;

a fourth signal generating means for generating a fourth signal representative of a desired passenger room temperature in response to at least said second signal;

a first arithmetic means for calculating a desired blown air temperature under a calculation model programmed in a ROM of a microcomputer on the basis of only said first and said second signals;

a second arithmetic means for calculating a desired blow air flow of said blower means on the basis of said second and said third signals; and

means for controlling operation and non-operation of a compressor operatively associated with an evaporator upstream of the heater core on the basis of ambient temperature;

means for adjusting a blown air temperature on the basis of a difference between said fourth signal and said third signal when said difference equals or exceeds an absolute predetermined value, and for selecting, when such difference is below said absolute predetermined value, a blown air temperature obtained in advance on the basis of a thermal load of the passenger room, in accordance with arithmetic results of said first arithmetic means, and means for adjusting a blow air flow on the basis of said second arithmetic means.

2. An air-conditioner mounted on a vehicle comprising:

a blower means for delivering air into a passenger room;

a heater core through which hot water circulates to heat the air from said blower means;

an air mixing door disposed for adjusting a mixture ratio between cold air flowing in a bypass passage bypassing said heater core, and hot air to be directed to said heater core;

an outside temperature sensor for generating a first signal in response to the outside temperature;

a passenger room temperature setter for generating a second signal in response to a set passenger room temperature;

a passenger room temperature sensor for generating a third signal in response to a passenger room temperature;

a fourth signal generating means for generating a fourth signal representative of a desired passenger room temperature in response to at least said second signal;

a first arithmetic means for calculating a desired blown air temperature in accordance with a ROM microcomputer program on the basis of only said first and said second signals;

a second arithmetic means for calculating a desired blow air flow of said blower means on the basis of said second and said third signals; and

means for controlling operations and non-operations of a compressor operatively associated with an evaporator upstream of the heater core on the basis of ambient temperature;

means for adjusting a blown air temperature on the basis of a difference between said fourth signal and said third signal when said difference exceeds an absolute predetermined value, and for selecting, when such difference is below said absolute predetermined value, a blown air temperature obtained in advance on the basis of a thermal load of the passenger room, in accordance with arithmetic results of said first arithmetic means, and means for adjusting a blow air flow on the basis of said second arithmetic means.