A kind of engine air intake preheating control circuit and control method

Abstract

The invention discloses an engine intake air preheating control circuit and a control method. The control circuit comprises a high-side relay K1, a low-side relay K2, an electronic control unit ECU and a power supply, wherein a pin 1 at a K1 input end and a pin 1 at a K2 input end are connected with a positive electrode Vbb of the power supply; a pin 2 at the K1 input end and a pin 2 at a K2 input end are separately connected with control ends CTL1 and CTL2 of the ECU; a pin 3 at a K1 output end is connected with a pin 4 at a K2 output end through load GH1; a pin 4 at the K1 output end is connected with the positive electrode Vbb of the power supply; a pin 3 at the K2 output end is grounded; and a negative electrode of the power supply is grounded. The engine intake air preheating control circuit can reduce control circuit failure as well as a series of potential safety hazards as a result of the control circuit failure as the relays have contact adhesion after an engine is preheated.

Description

technical field [0001] The invention relates to the field of engine intake preheating, in particular to an engine intake preheating control circuit and a control method. Background technique [0002] Intake air preheating or engine in-cylinder preheating is a commonly used technology to improve the low temperature starting performance of the engine. Since intake air preheating or in-cylinder preheating both require a large current, the common way is to drive through a relay, that is, the electronic control unit drives the coil of the relay to make the contacts of the relay engage, and the current flows through the intake air preheating device or The in-cylinder glow plugs increase the local temperature to improve engine starting performance. The problem with this driving method at present is that when a large current flows through the contacts of the relay, it will cause contact adhesion. Due to contact adhesion, the preheating device will be energized for a long time. In ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to propose an improved air intake preheating control circuit scheme for the phenomenon that relay contacts are prone to stick during the existing engine air intake preheating, which can greatly reduce the occurrence of relay contact adhesion. The resulting failure of the control circuit can be effectively detected in the event of contact sticking

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