JPS6141941Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an apparatus for supplying fuel for regenerating a filter that filters and collects particulates contained in the exhaust gas of an internal combustion engine by combustion.

Since diesel engines emit a large amount of fine particles, it has been devised that a filter is provided to prevent the fine particles from being released into the atmosphere and to collect them. However, in the case of this filter, as particles accumulate on its surface, the ventilation resistance of the filter increases, so measures are taken to regenerate the filter by heating and incinerating the collected particles. .

As a heating means for filter regeneration, it has been proposed to provide an oil burner as disclosed in Japanese Utility Model Application No. 57-136814. This requires a pressurizing pump and an ignition means for igniting the fuel injected from the pressurizing pump separately from the engine system, which inevitably increases the size and cost of the device and also requires installation. Piping etc. were a hassle.

For this reason, the aim of this invention is to reduce the size and cost of the device without having a pressure pump and ignition device for particulate combustion. An injection nozzle for particulate combustion is provided upstream of the filter that filters and collects the particulate matter, and the injection nozzle for particulate combustion is supplied with the fuel in the pump chamber of the distribution type fuel injection pump, and the injection nozzle for particulate combustion is The present invention provides a fuel supply device for treating exhaust particulates of an internal combustion engine, which is opened under conditions where at least a predetermined amount of particulates is collected and the exhaust temperature is high.

Therefore, the fuel in the chamber of the distribution type fuel injection pump is introduced as fuel for burning the filter for particulate collection, and the fuel is supplied from the injection nozzle for particulate combustion provided upstream of the filter using the pressure in this chamber. This eliminates the need for a separate pressurizing pump, and also allows the injection nozzle for particulate combustion to be opened when the exhaust pressure is high, the particulate collection reaches a predetermined amount, and the exhaust temperature is high. Therefore, the fuel supplied from the injection nozzle for particulate combustion can be ignited without an ignition device, and the above-mentioned problem can be achieved.

Examples of this invention will be described below with reference to the drawings.

In FIG. 1, a schematic diagram of this invention is shown,
Reference numeral 1 denotes a diesel engine body of a vehicle, into which air is taken in through an air cleaner, an intake pipe, and an intake manifold (not shown), and fuel is injected from a distribution type fuel injection pump 2, which will be described below. The injected fuel is ignited within the cylinder and burns.
The combustion energy rotates the engine as mechanical energy, and the combustion gas is transferred to the exhaust manifold 3.
It is then discharged from the exhaust pipe 4.

The distribution type fuel injection pump 2 has the purpose of supplying fuel to the engine as described above, and the purpose of supplying the fuel inside the chamber to the injection nozzle for particulate combustion using its internal pressure. To explain, fuel is supplied to a pump chamber 33 within a pump housing 31 by an oil feed pump 32, and the internal pressure of the pump chamber 33 is controlled by a pressure control valve (not shown) related to engine speed, as is well known. As the rotation speed increases, the internal pressure increases proportionally (up to about 8 kg/ ^cm2 ).
do.

Sliding hole 3 provided in pump housing 31
A plunger 35 is slidably mounted on 1a, and this plunger 35 is caused to reciprocate and rotate at the same time by means to be described later.

That is, the drive shaft 36 and a cam disk 37 fixed to the base of the plunger 35 are connected in the rotational direction via the driving disk, and the cam surface of the cam disk 37, which has a cam surface corresponding to the number of cylinders of the engine, is connected to the roller holder 38. By pressing the plunger spring 40 against the roller 39 held by the plunger 39, the plunger 35 is caused to simultaneously perform reciprocating motion for sucking in and pumping fuel and rotation for distributing fuel.

When the plunger 35 is in the suction stroke moving to the left in the figure, the fuel in the pump chamber 33 is in the supply passage 4.
1 from the suction port 42 to the plunger chamber 44 via one of a plurality of suction groups 43 formed in the axial direction on the outer periphery of the head of the plunger 35.

When the plunger 5 moves to the pressure stroke, the suction port 42 and the suction group 43 are separated, the fuel in the plunger chamber 44 is compressed, and the plunger 3
It is supplied from the distribution port 46 to one of the distribution passages 47 (the number of cylinders are provided in the circumferential direction) through the vertical hole 45 in the cylinder 5, and is then sent from the delivery valve 48 to an injection nozzle (not shown), and is fed into the cylinder. is injected to.

In addition, a control sleeve 49 is provided in the portion of the plunger 35 that protrudes toward the pump chamber 33.
is slidably inserted therein, and when the cut-off port 50 connected to the vertical hole 45 of the plunger 35 comes off the upper edge of the control sleeve 49 and opens into the pump chamber 33, fuel flows into the pump chamber 33.
3, the delivery to the delivery valve 48 is stopped and the injection ends. Therefore, the end of injection can be changed by adjusting the position of the control sleeve 49.
That is, the injection amount can be controlled; for example, by moving the control sleeve 49 to the left in the figure, the injection amount is reduced.

The control sleeve 49 is engaged with one end of a start lever 52 whose intermediate portion is pivotally supported by a support shaft 51, and the lever 52 uses the support shaft 51 as a fulcrum with the elasticity of a start spring 53 to act as an anti-tension lever. The centrifugal force governor 5 is displaced in the 54 direction, and the centrifugal force governor 5 is displaced in the other end and on the side opposite to the tension lever.
It is engaged with the sleeve 56 of No. 5.

The tension lever 54 has a centrifugal force governor 55.
A governor spring 58 and an idle spring 59 whose spring force is adjusted by a speed lever 57 that interlocks the accelerator are operated in a direction opposite to the direction of operation of the governor spring 58 and the idle spring 59.

In this way, the position of the tension lever 54 is controlled by balancing the acting force of the centrifugal force governor 55 and the acting force of the governor spring 58, and the position of the tension lever 54 is controlled.
The position of the control sleeve 49 is adjusted through the control sleeve 49, thereby controlling the injection amount.

In such a distribution type fuel injection pump, a pipe 7 is connected to the pump chamber 33 for supplying fuel in the pump chamber 33 to an injection nozzle 6 for particulate fuel, which will be described below.

The exhaust pipe 4 is provided with a filter 5 for collecting particulates in the exhaust gas, and the filter 5 is made of, for example, porous ceramics. Further, the exhaust pipe 4 is provided with an injection nozzle 6 for particulate combustion on the upstream side of the filter 5, and this injection nozzle 6 for particulate combustion has a configuration as shown in FIG. The valve body 9 is axially biased by a spring 10 and the nozzle hole 11 is closed. When the coil 12 is energized, the valve body 9 is displaced against the spring 10.
The injection hole 11 is opened and fuel is injected into the exhaust pipe.
Furthermore, the exhaust pipe 4 is provided with an exhaust pressure detector 13 for detecting the exhaust pressure in the exhaust pipe, and an exhaust temperature detector 14 for detecting the exhaust temperature in the exhaust pipe. An electric signal (resistance value change) is input from the control circuit 18 to the control circuit 18 described below.

The rotation speed detector 15 detects the engine rotation speed as a pulse, and the load detector 16 detects the rotation angle of the speed lever 17 of the distributed fuel injection pump 2 as an electric signal (resistance value change). The detection signal is input to a control circuit 18 described below.

The control circuit 18 controls the opening and closing of the injection nozzle 6 for particulate combustion described above, and as the particulates in the exhaust gas are collected by the filter 6, the ventilation resistance of the filter increases due to the accumulation of particles, and the ventilation resistance of the filter increases until the desired value, i.e. , when the particulate collection reaches a predetermined amount,
If the exhaust temperature is high, for example 500° C. or higher, an open signal is output to the injection nozzle 6 for separate particle combustion. This open signal is for a predetermined period of time, for example, about 2 minutes.

Note that the control circuit 18 is input with the rotation speed and load signal, but this may be used in addition to the above-mentioned conditions if necessary. It is used to cut.

In the above configuration, when the exhaust gas passes through the exhaust pipe 4, the particulates contained therein are collected by the filter 5, and the adhesion of particulates gradually increases, causing the filter 5 to become clogged. This causes problems with the normal flow of exhaust gas.

As a result, the exhaust pressure inside the exhaust pipe 4 increases,
When the exhaust pressure reaches a predetermined value (for example, 300 mmHg), it is detected that the amount of fine particles has reached a predetermined amount, and the filter 5 is in a state where it should be regenerated.
However, the fuel supplied from the injection nozzle 6 for particulate combustion must be ignited, and when the conditions are suitable for this, that is, when the exhaust temperature reaches 500°C,
An open signal is issued from the control circuit 18, the injection nozzle 6 is opened, and fuel is injected into the exhaust pipe by the pressure of the pump chamber 33 of the distribution type fuel injection pump 2 (rising to a maximum of 8 kg/cm ² ). The filter 5 is regenerated because it is ignited by the exhaust temperature and burned by the excess oxygen contained in the exhaust gas, and the combustible particulates adhering to the filter 5 are burned.

The fuel injection time from the injection nozzle 6 (for example, about 2 minutes) has been specified, and if the particulate removal operation has been completed, but if particulates still remain and the exhaust pressure is high, the fuel injection will be performed again under the above conditions. Become.

As described above, according to this invention, the fuel to be supplied to the injection nozzle for particulate fuel is supplied using the pump chamber internal pressure of the distribution type fuel injection pump, which eliminates the need for a special pressure pump. Moreover, the ignition of the fuel injected into the exhaust pipe from the injection nozzle for particulate combustion also has the advantage that by selecting the exhaust temperature, the fuel can be completely ignited and combusted, making an ignition means unnecessary. Furthermore, since the above-mentioned pressurizing pump and ignition means are not required, the particulate removal device can be provided at a considerably low cost.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing an embodiment of this invention, Figure 2
The figure is a longitudinal sectional view of a distribution type fuel injection pump, and FIG. 3 is a sectional view of an injection nozzle for particulate combustion. 2... Distribution type fuel injection pump, 5... Filter, 6... Injection nozzle for particulate combustion, 33...
pump chamber.

Claims (1)

[Scope of utility model registration request] An injection nozzle for particulate combustion is provided upstream of a filter that filters and collects particulates contained in the exhaust gas, and this injection nozzle for particulate combustion is supplied with fuel in the pump chamber of a distribution type fuel injection pump, and the particulates are A fuel supply device for treating exhaust particulates of an internal combustion engine, characterized in that the combustion injection nozzle is opened under conditions where at least a predetermined amount of particulates is collected and the exhaust temperature is high.