JP6375764B2 - Ignition control device - Google Patents

Description

  The present invention relates to an ignition control device for controlling discharge energy output from a spark plug.

  To prevent starting failure due to smoldering spark plugs and fluctuations in rotation during idling, an ignition coil with increased ignition energy is used to control the ignition energy with a constant energization time regardless of the operating state. It was trying to generate energy.

  According to this technology, power consumption increases and fuel consumption deteriorates, and the ignition coil generates heat and the spark plug electrode wears.

  In order to solve this problem, Patent Document 1 discloses a technique for controlling the discharge time of the spark plug so as to supply the minimum amount of ignition energy according to the engine operating state such as the air-fuel ratio. .

JP 2000-291519 A

  However, regardless of the operating state, the ignitability is poor when the humidity is high, and even if ignition energy is supplied according to the operating state, the poor ignitability when the humidity is high cannot be improved.

  Accordingly, an object of the present invention is to provide an ignition control device that can maintain good ignitability by outputting appropriate discharge energy even when the humidity is high and misfire is likely to occur.

An ignition control device according to the present invention includes an ignition device having an ignition plug provided in a combustion chamber of an internal combustion engine, a discharge energy calculation unit that calculates discharge energy so as to maintain the ignitability of the ignition plug, and the ignition plug And a discharge energy control unit that controls the discharge energy to be output to be the discharge energy calculated by the discharge energy calculation unit, wherein the humidity detection unit detects the humidity of the intake air into the combustion chamber. The ignition device has an ignition coil, and the discharge energy calculation unit increases the discharge current and increases the discharge voltage as the humidity detected by the humidity detection unit increases. And increasing the number of spark plugs for one combustion chamber reduces the discharge energy of the spark plugs. Wherein the enhancing of can.

  According to the present invention, even when the humidity is high and misfire is likely to occur, good ignitability can be maintained by outputting appropriate discharge energy.

FIG. 1 is a block diagram of an ignition control apparatus according to an embodiment of the present invention and a schematic configuration of a part of an internal combustion engine. FIG. 2 shows the relationship between the humidity and the length of the energization time used when controlling the discharge energy using the length of the energization time to the ignition coil in the ignition control device according to the embodiment of the present invention. It is a figure which shows an example of the map to represent. FIG. 3 is a diagram showing an example of a flowchart of the output control of the discharge energy of the spark plug executed in the ignition control apparatus according to the embodiment of the present invention.

  Hereinafter, an ignition control apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

  In the following description, “humidity” is a numerical value representing the amount of water vapor contained in the air, which is expressed as relative humidity or absolute humidity.

  In the present embodiment, the internal combustion engine 60 performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while the piston 22 reciprocates twice within the cylinder 70 as a cylinder. A description will be given assuming that the engine is constituted by a 4-cycle gasoline engine that performs ignition during the expansion stroke.

  As shown in FIG. 1, the internal combustion engine 60 includes a piston 22 in a cylinder 70. The piston 22 is connected to a crankshaft 24 that is an output shaft of the internal combustion engine 60 via a connecting rod 23. The reciprocating motion of the piston 22 is replaced by the rotation of the crankshaft 24 by the connecting rod 23.

  Further, the internal combustion engine 60 includes a port injector 66 that injects fuel from the intake passage 62 toward the intake port 62 a of the combustion chamber 63. The port injector 66 is supplied with fuel stored in a fuel tank (not shown).

  In the internal combustion engine 60, an air-fuel mixture composed of fuel injected from the port injector 66 and air flowing through the intake passage 62 (hereinafter referred to as “intake air”) is filled in the combustion chamber 63. Ignition by the spark plug 72 is performed.

  At this time, the momentum of combustion of the air-fuel mixture in the combustion chamber 63 changes according to the humidity of the intake air. For example, when the humidity of the intake air increases, the combustion momentum of the air-fuel mixture decreases, and the ignition plug misfires depending on the situation. In order to prevent such a misfire situation, the discharge energy control unit 50 controls the discharge of the spark plug 72 as will be described later.

  When the air-fuel mixture after ignition burns, the piston 22 reciprocates in the cylinder 70 by the combustion energy at that time, and the crankshaft 24 rotates accordingly. The air-fuel mixture after combustion is sent to the exhaust passage 68 as exhaust.

  The intake camshaft 25 rotates in response to the rotation transmission from the crankshaft 24. As the intake camshaft 25 rotates, the intake valve 26 opens and closes. By this opening / closing operation, the combustion chamber 63 and the intake passage 62 are communicated or blocked.

  Further, the exhaust camshaft 27 rotates in response to the rotation transmission from the crankshaft 24. As the exhaust camshaft 27 rotates, the exhaust valve 28 opens and closes. By this opening / closing operation, the combustion chamber 63 and the exhaust passage 68 are communicated or blocked.

  The internal combustion engine 60 configured as described above is controlled by an ECU (Engine Control Unit) 100 mounted on the vehicle.

  The ECU 100 includes a microcomputer including, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output interface, and the like.

  The CPU uses the temporary storage function of the RAM and performs signal processing according to a program stored in advance in the ROM. Various control constants and various maps are stored in advance in the ROM.

  For example, the RAM stores a map showing the relationship between the intake air humidity and the energization time to the ignition coil as shown in FIG. The map of FIG. 2 can be used when the magnitude of the discharge energy supply of the spark plug 72 is controlled by changing the length of the energization time to the ignition coil in accordance with the humidity.

  As shown in the map of FIG. 2, the energization time to the ignition coil is lengthened as the humidity increases. As a result, the discharge energy of the spark plug 72 can be increased to prevent the spark plug 72 from misfiring.

  Referring back to FIG. 1, the description continues and the ECU 100 constitutes an ignition control unit 10 that is an ignition control device by a program stored in advance in the ROM of the ECU 100, and the ignition control unit 10 includes a discharge energy calculation unit 40. And the discharge energy control part 50 is comprised.

  An operation state detection unit 20 that detects the operation state of the internal combustion engine and a humidity detection unit 30 that detects the humidity of the intake air supplied to the combustion chamber 63 are connected to the input port of the ECU 100.

  The operating state detection unit 20 detects at least one of the rotational speed of the internal combustion engine, the intake air temperature, the air-fuel ratio, the EGR (Exhaust Gas Recirculation) amount, and the like.

  The ignition device 71 of the spark plug 72 is connected to the output port of the ECU 100, and the discharge energy control unit 50 controls the discharge energy of the spark plug 72. The ignition device 71 includes an igniter and an ignition coil (not shown).

  The humidity detector 30 may be provided at any position as long as the humidity of the intake air (that is, air) supplied to the combustion chamber 63 can be detected. For example, the humidity detection unit 30 may be provided in the intake passage 62 that supplies intake air to the combustion chamber 63, or may be provided at a position where outside air is taken into the intake passage 62.

  The discharge energy calculation unit 40 calculates the discharge energy that maintains ignitability so that the ignition plug 72 does not misfire in consideration of the humidity of the intake air detected by the humidity detection unit 30.

  In addition to the humidity of the intake air, the discharge energy calculation unit 40 further considers at least one of, for example, the rotational speed of the internal combustion engine, the intake air temperature, the air-fuel ratio, the EGR amount, and the like detected by the operating state detection unit 20. Thus, the discharge energy necessary for maintaining the ignitability so that the spark plug 72 does not misfire may be calculated.

  The discharge energy control unit 50 controls the discharge energy of the discharge plug in the combustion chamber 63 by controlling at least one of the length of the energization time to the ignition coil, the magnitude of the discharge voltage, and the number of plugs that perform discharge. Control the size of.

  FIG. 3 is a diagram illustrating an example of a flowchart of the discharge energy output control of the spark plug 72 executed in the ignition control unit 10.

  First, the ignition control unit 10 receives a signal indicating the operation state detected by the operation state detection unit 20, and stores it in the RAM (step S1).

  Next, the ignition control unit 10 receives a signal indicating the humidity of the intake air detected by the humidity detection unit 30, and stores it in the RAM (step S2).

  Next, the discharge energy calculation unit 40 is expected to output from the spark plug 72 based on the value of the intake air humidity stored in the RAM and, if necessary, the value indicating the operating state stored in the RAM. Is calculated and stored in the RAM (step S3).

  Next, the discharge energy control unit 50 controls the operation of the ignition device 71 so that the discharge energy corresponding to the magnitude of the discharge energy stored in the RAM is output from the ignition plug 72 (step S4).

  Control of the discharge energy of the spark plug 72 can be performed, for example, by changing the length of the energization time to the ignition coil of the ignition device 71, the magnitude of the discharge voltage, and the number of plugs that perform discharge.

  When the control of the discharge energy of the spark plug 72 is to be executed, for example, by the length of the energization time to the ignition coil of the ignition device 71, in step S4, the discharge energy control unit 50 displays the map shown in FIG. From the RAM of the ECU 100, and from the map, the energization time to the ignition coil corresponding to the magnitude of the intake air humidity detected by the humidity detection unit 30 is obtained, and based on this, the discharge energy control unit 50 The operation of 71 is controlled.

  When the control of the discharge energy of the spark plug 72 in step S4 is completed, the discharge energy output control process ends.

  According to the above embodiment, even when the intake air humidity is high and the spark plug 72 is prone to misfire, the ignition control unit 10 can maintain good ignitability by causing the spark plug 72 to output appropriate discharge energy. Can be provided.

  As described above, the embodiments of the present invention have been described, but it is obvious that those skilled in the art can make changes, modifications, or alterations without departing from the scope of the present invention. Such alterations, modifications, and variations and equivalents are intended to be included within the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Ignition control part 20 Operation state detection part 22 Piston 23 Connecting rod 24 Crankshaft 25 Intake camshaft 26 Intake valve 27 Exhaust camshaft 28 Exhaust valve 30 Humidity detection part 40 Discharge energy calculation part 50 Discharge energy control part 60 Internal combustion engine 62 Intake passage 62a Intake port 63 Combustion chamber 66 Port injection injector 68 Exhaust passage 70 Cylinder 71 Ignition device 72 Spark plug

Claims (1)

An ignition device having an ignition plug provided in a combustion chamber of an internal combustion engine;
A discharge energy calculation unit for calculating discharge energy so as to maintain the ignitability of the spark plug;
In the ignition control device comprising: a discharge energy control unit that controls the discharge energy output from the spark plug to be the discharge energy calculated by the discharge energy calculation unit;
A humidity detector for detecting the humidity of the intake air into the combustion chamber;
The ignition device has an ignition coil,
The discharge energy calculation unit increases the energization time to the ignition coil and increases the discharge voltage as the humidity detected by the humidity detection unit increases, and the ignition is performed for one combustion chamber. An ignition control device characterized in that the magnitude of discharge energy of the ignition plug is increased by increasing the number of plugs .

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