JPS5924869Y2 - Exhaust gas purification device for multi-cylinder internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an exhaust gas purification device for a multi-cylinder internal combustion engine.

In the conventional device, the cam crest of the cam cylinder, which is the ignition timing determining member, is formed so that the ignition timing of each cylinder in a multi-cylinder engine is the same.

By the way, in recent years, among the multiple cylinders that are used to efficiently purify toxic exhaust gases (HC, CO, etc.) emitted from multi-cylinder engines as part of exhaust gas countermeasures, cylinders that inhale rich mixtures and cylinders that are We actively provide a cylinder where the air-fuel mixture is inhaled.
A method has been proposed in which toxic exhaust gas discharged from a cylinder with a rich mixture is subjected to an oxidation reaction with surplus oxygen discharged from a cylinder with a lean mixture to purify the toxic exhaust gas.

However, it is almost impossible to actively discharge toxic exhaust gas and surplus oxygen from each cylinder side using the conventional ignition timing determining member.

In order to make this possible, the structure becomes very complicated, but one way is to connect two ignition signal generators (interrupter contacts, etc.) to the ignition timing determining member (cam cylinder, etc.).
There are devices that generate two types of ignition signals at different times by arranging them with a predetermined phase difference.

In this case, two ignition signal generators are required, and a large installation space is required, resulting in an increase in the size of the main body of the power distributor, which has significant disadvantages in practical use.

This idea was made in view of the above-mentioned circumstances, and it generates ignition signals at different times by changing the shape of the ignition timing determining member, and uses these at least two types of ignition signals to differentiate cylinders with a rich mixture from cylinders with a lean mixture. Multi-cylinder internal combustion aims to purify toxic exhaust gas by appropriately igniting the cylinders and oxidizing the toxic exhaust gas discharged from cylinders with rich mixtures using excess oxygen discharged from lean mixtures. The present invention provides an engine exhaust gas purification device.

The embodiment shown in FIGS. 1 to 3 will be described below.

In the figure, 1 represents the first, second, third, and fourth cylinders 1a.

It is a 4-cylinder internal combustion engine consisting of lb, IC, and ld, and the firing order is 1st cylinder 1a → 3rd cylinder 1C → 4th cylinder 1d →
The second cylinder 1b, the first cylinder 1a and the fourth cylinder 1d
A rich mixture is inhaled into the second cylinder 1b and the third cylinder IC.
A lean mixture is inhaled.

2a, 2b, 2C, and 2d are these cylinders 1a and lb. I
Spark plugs attached to C and ld, 3 is a DC power supply,
Reference numeral 4 denotes an ignition coil that is powered by this DC power source 3, and is composed of a primary coil 4a and a secondary coil 4b.

Reference numeral 5 denotes a rotary shaft that is rotationally driven in synchronization with the four-cylinder engine 1, and although not shown, is rotatably supported by the power distributor housing.

Reference numeral 6 denotes a cam cylinder which is loosely fitted onto this rotating shaft 5 and is an ignition timing determining member which is rotationally driven via a governor advance mechanism (not shown). ld
The first cam ridges 5a, 5c are the ignition timing determining parts of the
Second and third cylinders lb and second cam ridges 6b and 6d, which are the ignition timing determining section of the IC, are formed, and the second cam ridges 6b and 6d are similar to the first cam ridges 5a, 5c, it is formed at a position advanced by an angle θ in the counter-rotational direction.

Reference numeral 7 indicates an interrupter contact which interrupts the current flowing through the primary coil 4a of the ignition coil 4 to generate an ignition voltage in the secondary coil 4b, and 7a indicates a cam heel of the contact 7 connected to the cam ridges 6a to 6d. , 8 is a spark extinguishing capacitor of the contact 7, and 9 is a power distribution device (not shown) that distributes the ignition voltage generated in the secondary coil 4b of the ignition coil 4 to each of the spark plugs 2a, 2b, 2C, and 2d. is a part of the main body of the power distributor, and is composed of the following elements.

10 is a center electrode, 11 a , 11 b , 11 , which is installed on a distributor cap (not shown) and to which an ignition voltage is applied;
C, 11d is also installed on the cap, and each spark plug 2
The peripheral electrodes connected to terminals a to 2d are arranged in positions similar to the positions of the cam ridges 6a to 6d of the cam cylinder 6, that is, the arrangement relationship shown in FIG. 3.

Reference numeral 12 denotes a power distribution rotor that is rotated in synchronization with the engine 11 and sequentially distributes the ignition voltage to the center electrode 10 to each of the peripheral electrodes 11 a to 11 d.

Next, the operation will be described. First, when the rotating shaft 5 is driven by the multi-cylinder engine 1, the cam cylinder 6 is rotationally driven in the direction of the arrow shown in FIG.

Therefore, when the cam cylinder 6 rotates, the cam ridges 6a to 6d
The interrupter contact 7 is opened and closed as shown in FIG.

That is, the interrupter contact 7 is first connected to A by the first cam ridge 6a.
position, the circuit is opened (OFF), and then the circuit is opened for a predetermined period (ignition voltage oscillation duration), and then again for a predetermined period (required for the current flowing through the primary coil 4a of the ignition coil 4 to rise to a predetermined value). time), the circuit is closed (ON), and this time the circuit is opened again by the second cam ridge 6b at a position θ angle ahead of the original (conventional opening position) position, and then the circuit is opened for a predetermined period of time. and other first and second
The cam ridges 6C and 6d are also opened and closed in the same manner.

Now, when the breaker contact 7 is closed to ignite and burn the rich/lean mixture in each cylinder, the primary coil 4a of the ignition coil 4 is supplied with a primary current from the DC power source 3 via this contact 7. is energized.

Now, when it comes to the ignition timing of the first cylinder 1a, the power distribution rotor 12
Since the cam cylinder 6 is also rotated at the same time as the cam cylinder 6 is rotated to face the peripheral electrode 11a, the interrupter contact 7 is opened at the A position by the first cam ridge 6a.

When the contact 7 is opened, an ignition voltage is generated in the secondary coil 4b of the ignition coil 4, and this ignition voltage is transmitted from the power distribution rotor 12 to the ignition plug 2a of the first cylinder 1a via the peripheral electrode 11a. Since the electricity is distributed, the ignition plug 2a discharges sparks to suitably burn the rich mixture.

Next, when it comes to the ignition timing of the third cylinder 1C, the power distribution rotor 1
2 is rotated so that it faces the peripheral electrode 11b, and at the same time, the cam cylinder 6 is also rotated, so that the interrupter contact 7 is opened at the second cam ridge 6b at position B, which is advanced by an angle of θ.

The ignition voltage generated in the secondary coil 4b is then distributed from the power distribution rotor 12 to the ignition plug 2C of the third cylinder 1C via the peripheral electrode 11b, and the ignition plug 2C discharges sparks to generate a lean mixture. Burn properly.

Thereafter, in the same way, the rich mixture in the fourth cylinder 1d, then the rich mixture in the second cylinder 1d.
The lean air-fuel mixture in cylinder 1b is combusted.

In this way, by changing the ignition timing of the first and fourth cylinders 1a and ld and the second and third cylinders lb and IC, the
Toxic exhaust gas (HC) discharged from the 4th cylinder 1a, ld
, CO) is oxidized by excess oxygen discharged from the second and third cylinders 1d and IC, and purified into harmless exhaust gas, thereby taking measures against exhaust gases.

As a result, there is an advantage that the air pump, air control valve, AGR valve, etc., which were conventionally equipped for exhaust gas countermeasures, are not required.

In the above embodiment, the first and fourth cylinders 1a and ld are set to a rich mixture, and the second and third cylinders lb and IC are set to a lean mixture, but the settings may be reversed. Also, each cylinder may be set to a different air-fuel ratio, and in this case, the phase angles between the cam ridges must all be different.

Furthermore, although the cam cylinder 6 is used as the ignition timing determining member, when used in a semiconductor ignition device, a rotating body having magnetic pole portions 132 to 13d, which are ignition timing determining portions, formed on the outer periphery as shown in FIG. 13 and a fixed body 14 having a magnetic pole portion 14a facing the magnetic pole portions 131 to 13d with a gap therebetween, similar effects can be obtained. All of the above institutions have the same effect.

As described above, this invention can adjust the ignition timing of the first cylinder in which the air-fuel mixture is sucked and the ignition timing in which the lean air-fuel mixture is sucked by simply changing the arrangement of the first and second ignition timing determining parts provided in the ignition timing determining member. The ignition timing of the second cylinder, that is, the ignition timing that is a predetermined period ahead of the ignition timing of the first cylinder, can be easily obtained, and the ignition voltage of the ignition coil generated corresponding to this ignition timing of the first cylinder can be easily obtained. The power distribution device distributes power to the first spark plug of the first cylinder to combust the rich air-fuel mixture in the first cylinder and emit toxic exhaust gas, and also generates an ignition coil corresponding to the ignition timing of the second cylinder. By distributing the ignition voltage to the second spark plug of the second cylinder by the power distribution device, the lean mixture in the second cylinder is combusted and excess oxygen is exhausted, and this excess oxygen causes the toxic exhaust gas to undergo an oxidation reaction. Therefore, toxic exhaust gas can be purified into harmless exhaust gas, thereby decomposing exhaust gas pollution.

Moreover, the first and second peripheral electrodes of the power distribution device that distributes the ignition voltage generated at each ignition timing of the first and second cylinders correspond to the arrangement positions of the first and second ignition timing determining portions of the ignition timing determining member. Because they are arranged in similar shapes, the ignition voltage can be reliably distributed to the first and second cylinders without any time delay, which has the practical effect of making the combustion of rich and lean mixtures more efficient. .

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of an ignition system showing an embodiment of this invention, Fig. 2 is a structural diagram of the ignition signal generating section in Fig. 1, and Fig. 3 is a diagram of the power distribution in Fig. 1. FIG. 4 is an explanatory diagram of the operation of the circuit shown in FIG. 1, and FIG. 5 is a structural diagram of a magnet generator showing another embodiment of the invention. In the figure, 1 is a 4-cylinder engine, 1 a, 1 b, I C
, 1d are the first, second, third, and fourth cylinders, 2 a , 2
b, 2C, 2d are spark plugs, 3 is a DC power supply, 4 is an ignition coil, 5 is a rotating shaft, 6 is a cam cylinder, 6a, 6b
, 6 C, 6d are cam crests, 7 is a circuit breaker contact, 8 is a spark extinguishing capacitor, 9 is a power distribution device, 10 is a center electrode, 11
a, 11b, 11C, 11d are peripheral electrodes, 1
2 is a power distribution rotor, 13 is a rotating body, 13a, 13b
, 13C, 13d, 14a are magnetic pole parts, and 14 is a fixed body. In each figure, the same reference numerals indicate the same parts.

Claims (1)

[Scope of utility model registration request] The first cylinder is rotated in synchronization with the rotation of a multi-cylinder internal combustion engine consisting of a first cylinder that takes in a rich mixture and a second cylinder that takes in a lean mixture, and is located at a position corresponding to the ignition timing of the first cylinder.
An ignition timing determining member is provided with an ignition timing determining section, and a second ignition timing determining section is provided at a position corresponding to the ignition timing of the second cylinder, which is a predetermined period ahead of the ignition timing of the first cylinder; 1. In cooperation with the second ignition timing determining section, the first
an ignition signal generating member that generates an ignition signal at each of the ignition timings of the cylinder and the ignition timing of the second cylinder; a center electrode that receives an ignition voltage generated in the ignition coil based on the ignition signals generated at each of the ignition timings; A first peripheral electrode connected to a first spark plug attached to the first cylinder and provided at a position corresponding to the first ignition timing determining section; and a second spark plug attached to the second cylinder. The ignition voltage of the second peripheral electrode connected and provided at a position corresponding to the second ignition timing determining section and the center electrode is set to the first. It consists of a power distribution rotor that sequentially distributes power to a second peripheral electrode, and sequentially distributes the ignition voltage generated in accordance with each of the ignition timings to the first and second cylinders to create a rich and lean mixture in the first and second cylinders. The toxic exhaust gas discharged from the first cylinder and the surplus oxygen discharged from the second cylinder are inhaled, and the toxic exhaust gas is purified by an oxidation reaction with the surplus oxygen. An exhaust gas purification device for a multi-cylinder internal combustion engine equipped with a purification means.