ELECTRIC CONTROL SYSTEM FOR AUTOMOBILE EXHAUST EMISSION CONTROL SYSTEMS

• US 3,859,541 A
• Filed: 12/19/1973
• Issued: 01/07/1975
• Est. Priority Date: 12/26/1972
• Status: Expired due to Term

• Current Assignee: Hisato Wakamatsu, Shuzo Yoshida, Tadashi Hattori, Takamichi Nakase
• Original Assignee: Hisato Wakamatsu, Shuzo Yoshida, Tadashi Hattori, Takamichi Nakase
• Inventors: Hattori, Tadashi, Wakamatsu, Hisato, Nakase, Takamichi, Yoshida, Shuzo
• Primary Examiner(s): Hohauser, Herman J.
• Application Number:
  US05/426,199
• Time in Patent Office: 384 Days
• Field of Search: 307/1R,120 180/15E,106 340/263 123/97B,97R,102,117,119
• US Class Current: 307/10.1
• CPC Class Codes: B60K 13/00 Arrangement in connection with combustion air intake or gas exhaust of propulsion units extensions for melting snow or ice on roads or like surfaces E01H5/00, E01H6/00; forming part of the engine F01N; supplying combustion engines with combustible mixtures or constituents F02M
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor

Abstract

There is provided an electric control system comprising a computing section integrally built into a MOS large scale integrated circuit (comprising a timing signal generating circuit, a speed signal generating circuit, a vehicle speed discriminating circuit, a control program circuit, etc.) which, in accordance with the digital signals from various sensors for detecting the operating conditions of an engine, generates solenoid signals for selectively controlling solenoid valves which effect exhaust emission control actions, and a power circuit for selectively actuating the solenoid valves in accordance with the solenoid signals from the computing section.

Claims

1. An electric control system for controlling soleNoid valves for actuating exhaust emission control systems comprising:

a pluraliity of sensors for generating digital signals indicative of operating parameters for setting control conditions, vehicle speed detecting means whereby a squarewave voltage having a frequency variable in response to the vehicle speed is generated when the vehicle speed is higher than a predetermined value and a squarewave voltage having a predetermined frequency is generated when the vehicle speed is lower than said predetermined value, a clock circuit for generating reference timing signals, a timing signal generating circuit connected to said clock circuit to generate predetermined timing signals, a speed signal generating circuit comprising a shift register and connected to said vehicle speed detecting means and said timing signal generating circuit to generate an output signal which is shifted one stage each time said squarewave signal attains a predetermined number of cycles in a predetermined time, a vehicle speed discriminating circuit connected to said speed signal generating circuit to determine whether the vehicle speed has reached a predetermined value, a control program circuit connected to said plurality of sensors and said vehicle speed discriminating circuit to perform a logical operation on said digital signals indicative of operating parameters and the signal from said vehicle speed discriminating circuit to generate a control signal, and means connected to said control program circuit to selectively actuate said solenoid valves.

2. An electric control system according to claim 1, wherein at least said timing signal generating circuit, the speed signal generating circuit, the vehicle speed discriminating circuit and the control program circuit are integrally built into a MOS integrated circuit.

3. An electric control system according to claim 1, wherein said clock circuit comprises a piezoelectric oscillator element.

4. An electric control system according to claim 1, wherein said control program circuit comprises an ROM.

5. An electric control system according to claim 1 further comprising an emergency command switch connected to said control program circuit, and a circuit for giving priority to the signal from said emergency command switch.

6. An electric control circuit according to claim 1, wherein said control program circuit supplies a control current to said solenoid actuating means only when said solenoid valve is actuated.