JPH0352972Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Technical field of the invention This invention is a diesel engine that collects and purifies particulate matter such as carbon particles (hereinafter referred to as particulate) contained in the exhaust gas of a diesel engine. The present invention relates to an engine particulate trap filter regeneration device.

(b) Background of the technology Generally, the exhaust gas of a diesel engine contains particulate, and if this particulate is released into the atmosphere as it is, it may cause problems such as air pollution. It is necessary to collect particulate matter with a filter member provided in the passage to purify the exhaust gas.
If particulates continue to be collected, the filter member will become clogged, and the pressure of the exhaust gas upstream of the filter member will increase, which will create operating resistance for the engine, resulting in a decrease in engine output. This problem occurs. Therefore, from the viewpoint of preventing a decrease in engine output, the clogging particulate is burned off using a heating device, and the filter member is regenerated.

(c) Prior art and problems Conventionally, as such a particulate trap filter regeneration device, for example,
No. 32114 or the one shown in Figure 4 is known.
As shown in FIG. 4, the conventional particulate trap filter regenerating device a consists of a trap cell having an open front face and a closing wall on the rear face, and a trap cell having an open rear face and a closing wall on the front face. It is composed of a filter member b that collects curate, a heater device c that is disposed in front of the filter member b and that regenerates the filter member b, and a housing d that houses the filter member b and the heating device c. There is.

However, the conventional particulate trap filter regeneration device requires a heater device that generates high heat in order to burn and remove the collected particulate and regenerate the filter member. For this reason, particulate matter is collected on the filter member during normal driving, and even if the exhaust gas pressure increases, there is a problem in that the filter member cannot be easily regenerated because high heat is required.

Furthermore, the installation of the heater device increases the weight of the vehicle, resulting in an increase in cost. In addition, in the above-mentioned conventional example, a heater device is used to regenerate the filter member, but
Similar problems occur when using burner devices.
Furthermore, when a burner device is used, there is a problem in that burner noise is generated due to combustion.

(d) Purpose of the invention The present invention was made to solve the above-mentioned problems.The purpose of the invention is to omit the heating device for regenerating the filter member and to maintain a constant pressure of exhaust gas during normal driving. It is an object of the present invention to provide a particulate trap filter regeneration device that maintains the temperature of the vehicle, allows filter members to be easily regenerated, reduces vehicle weight, reduces vehicle cost, and furthermore prevents generation of combustion noise when using a heating device. purpose.

(e) Structure of the invention In order to achieve the above object, the present invention provides a particulate trap filter regeneration device that is provided with a filter device for collecting particulate in the middle of the exhaust pipe, in which the exhaust gas is disposed downstream of the filter device. A switching device is provided to open and close the pipe, and this switching device is
The difference between the exhaust gas pressure detected by the exhaust pressure detection means upstream of the filter device and the exhaust gas pressure detected by the exhaust pressure detection means downstream of the filter device and upstream of the on-off valve is a predetermined difference. The control circuit is configured to close the exhaust pipe when the pressure is greater than .

(F) Embodiment of the invention An embodiment of the invention will be explained with reference to FIGS. 1 to 3.

FIG. 1 is an overall configuration diagram showing an embodiment of a particulate trap filter reproducing apparatus according to the present invention.

As shown in FIG. 1, the particulate trap filter regeneration device according to this embodiment includes a filter device 2 provided in the middle of an exhaust pipe 1 and consisting of a filter member and a casing, and a filter device 2 on the downstream side of this filter device 2. An opening/closing device 3 provided in the exhaust pipe 1 for opening and closing the exhaust pipe 1, a drive circuit 4 for driving this opening/closing device 3, a control circuit 5 for issuing a signal command to this driving circuit 4, and a control circuit 5 disposed upstream and downstream of the filter device 2. The exhaust pressure detecting means 6 and 7 are provided to send an exhaust pressure signal to the control circuit 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A particulate trap filter reproducing apparatus according to an embodiment of the present invention will be explained in detail below with reference to FIGS. 2 and 3.

As shown in FIG. 2, the opening/closing device 3 is composed of an opening/closing valve 8 and a connecting rod 9 for driving the opening/closing valve 8. The on-off valve 8 is a circular butterfly valve, and is rotatably mounted around a horizontal rotation axis 10 that crosses the exhaust pipe 1, so that the exhaust pipe 1 can be opened and closed. This on-off valve 8 is fixed to one end of a connecting rod 9, and this connecting rod 9 is rotatable around a horizontal pivot shaft 10 that intersects the exhaust pipe 1 together with the on-off valve 8.

Note that the on-off valve 8 is connected to the exhaust pipe 1 as shown in the figure.
The diameter is slightly smaller than the inner diameter of the valve, so that even when the valve is closed, the minimum amount of exhaust air required to drive the engine is maintained.

The drive circuit 4 includes a vacuum pump 11, a vacuum tank 12, a magnetic valve 13,
It is composed of an air filter 14 and a power chamber 15.

Vacuum pump 11 is installed in power chamber 15.
Negative pressure is supplied from the vacuum tank 12 and magnetic valve 13. The vacuum pump 11 is a device that generates negative pressure. The vacuum tank 12 is a tank that stores negative pressure. The magnetic valve 13 receives a signal command from the control circuit 5 and supplies negative pressure from the vacuum tank 12 to the power chamber 15. The push rod 15a of the power chamber 15 is freely linked to the other end of the connecting rod 9 so as to be capable of linear displacement.

A microcomputer is incorporated in the control circuit 5, which inputs an exhaust pressure signal and sends a signal command to the magnetic valve 13 to open or close the on-off valve 8 according to the flowchart shown in FIG.

This exhaust pressure signal is detected by exhaust pressure detection means 6 and 7. That is, the exhaust pressure detection means 6 provided upstream of the filter device 2 detects the engine exhaust pressure from the exhaust manifold of the engine.
P ₁ is detected. When particulates are collected and accumulated in the filter device 2, the exhaust pressure _P1 upstream of the filter device 2 increases the operating resistance.
It gets expensive. Also, the exhaust pressure upstream of this filter device 2
P ₁ depends on engine speed and engine load.
fluctuate.

Then, the exhaust pressure _{P 2} that has passed through the filter device 2 is detected by the exhaust pressure detection means 7 provided immediately downstream of the filter device 2 . Differential pressure of exhaust pressure upstream and downstream of filter device 2 (ΔP=P ₁ −
P ₂ ) can be used to check whether the filter is clogged. The exhaust pressure signals detected by the exhaust pressure detection means 6 and 7 are input to the control circuit 5, and the control circuit 5 calculates the differential pressure ΔP between the exhaust pressures upstream and downstream of the filter device 2. This exhaust pressure differential pressure ΔP
When the value K becomes larger than a predetermined value, a signal command to close the on-off valve 8 is output from the control circuit 5 to the magnetic valve 13. Further, when the differential pressure ΔP of the exhaust pressure becomes smaller than a predetermined value K, a signal command to open the on-off valve 8 is sent from the control circuit 5 to the magnetic valve 13.
Output to.

Next, the operation of the present invention will be explained with reference to the flowchart shown in FIG. When the engine starts (step S1), the exhaust pressure detection means 6 and 7 read the exhaust pressure _P1 upstream of the filter device 2 and the exhaust pressure _P2 downstream of the filter device 2 (step S2,
Step S3), and calculate the exhaust pressure differential ΔP (Step S4). Then, it is determined whether the differential pressure ΔP of the exhaust pressure has exceeded a predetermined value K (step
S5).

Particulate accumulates on the filter components,
When the exhaust pressure difference ΔP exceeds a predetermined value K in step S5, a signal command (step S6) to close the on-off valve 8 is output from the control circuit 5 to the magnetic valve 13, and negative pressure is released from the vacuum tank 12. The on-off valve 8 is closed by being sent to the power chamber 15 and pushing the push rod 15a in the direction of the arrow in FIG.

When the on-off valve 8 is closed, the temperature of the exhaust gas increases. This is considered to be the result of an increase in the exhaust pressure of the entire exhaust system as the on-off valve 8 is closed, causing an adiabatic change in the exhaust gas.

Further, it is more preferable to increase the engine rotation by pulling the throttle and injecting a large amount of fuel at the same time as the on-off valve 8 closes, thereby promoting a rise in exhaust gas temperature. In order to achieve low-temperature combustion, it is also possible to mix additives into the fuel to promote combustion.

Then, when the on-off valve 8 is closed and the particulate is burning, the exhaust pressures P ₁ and P ₂ upstream and downstream of the filter device 2 are read (step S7, step S8), and the differential pressure ΔP of the exhaust pressure is calculated. (Step S9). Next, it is determined whether the exhaust pressure differential ΔP has become less than a predetermined value K (step S10).

When the particulate is burned and the exhaust pressure difference ΔP becomes less than a predetermined value K in step S10, a signal command (step S11) to open the on-off valve 8 is output from the control circuit 5 to the magnetic valve 13, and the power chamber is closed. The negative pressure at 15 is released and the on-off valve 8 is opened.

Then, when the on-off valve 8 is open and particulate is accumulated in the filter member, the exhaust pressures P ₁ and P ₂ upstream and downstream of the filter device 2 are read (step S12, step S13), and the differential pressure of the exhaust pressure is read. Calculate ΔP (step S14). Then, it is determined whether the differential pressure ΔP of the exhaust pressure has exceeded a predetermined value K (step S15).

The particulate accumulates on the filter member,
When the differential pressure ΔP of the exhaust pressure exceeds a predetermined value K in step S15, a signal command (step S6) to close the on-off valve 8 is output from the control circuit 5 to the magnetic valve 13, and negative pressure is sent into the power chamber 15. and the on-off valve 8 is closed.

In addition, in the process of the above series of steps,
If the exhaust pressure difference ΔP is smaller than the predetermined value K in S5, the process returns to step S2 and the operations of step S2→step S3→step S4→step S5 are repeated. Further, if the differential pressure ΔP of the exhaust pressure is larger than the predetermined value K in step S10, the step
Return to S6, step S6 → step S7 → step
The operations of S8→step S9→step S10 are repeated. Furthermore, in step S15, if the differential pressure ΔP of the exhaust pressure is smaller than the predetermined value K, the step
Returning to S11, the operations of step S11→step S12→step S13→step S14→step S15 are repeated. Furthermore, since this type of particulate trap filter 2 uses unglazed ceramic, it is prone to cracking and chipping.
Moreover, since each layer is thin, it is difficult to reliably collect carbon. As a result, there is a possibility that the uncollected carbon flows out from the downstream side of the particulate trap filter 2 and is discharged to the outside via the exhaust pipe 1. At this time, the carbon flowing out may adhere to the opening/closing device 3 and cause the opening/closing device 3 to be in a closed state. However, in the present invention, when such a situation occurs, the downstream exhaust pressure P ₂
becomes large, and as shown in FIG. 3, ΔP≦K. Therefore, the opening/closing device 3 is opened and controlled so as not to place too much load on the engine.

The series of opening and closing operations of the on-off valve 8 described above are automatically performed by the control circuit 5. According to the embodiment with the above configuration, the particulate trap filter is automatically regenerated by using the heat of the exhaust gas, so a heating device for regenerating the filter member can be omitted. .

In this embodiment, the opening/closing operation of the on-off valve 8 is performed by the reciprocating movement of the push rod 15a of the power chamber 15.
This can also be achieved by a rotational movement of the horizontal rotational shaft 10.

(g) Effects of the invention As described above, according to the invention, it is possible to omit a heating device for regenerating the filter member, thereby keeping the exhaust gas pressure constant during normal driving, and easily replacing the filter member. It is possible to regenerate the fuel, reduce the weight of the vehicle, lower the cost of the vehicle, and furthermore, it is possible to prevent the generation of combustion noise when the heating device is used. In addition, carbon flowing out from the downstream side of the particulate trap filter adheres to the switchgear and closes it, increasing the exhaust pressure on the downstream side.
When a situation such as a particulate trap filter becoming blocked occurs, the exhaust gas pressure detected by exhaust pressure detection means provided separately on the upstream and downstream sides of the particulate trap filter When the differential pressure calculated from ΔP≦K becomes smaller than a predetermined value (ΔP≦K), the opening/closing device is opened, and it becomes possible to control the engine so as not to put too much load on it.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a particulate trap filter reproducing device according to an embodiment of the present invention, Fig. 2 is an enlarged explanatory diagram of the main parts, and Fig. 3 is a flowchart showing the control operation of the embodiment of the present invention. FIG. 4 is a sectional view of a conventional particulate trap filter regeneration device. DESCRIPTION OF SYMBOLS 1...Exhaust pipe, 2...Filter device, 3...Switching device, 4...Drive circuit, 5...Control circuit, 6...
...Exhaust pressure detection means upstream of the filter device, 7...Exhaust pressure detection means downstream of the filter device, 8...Opening/closing valve, 11...Vacuum pump, 12...Vacuum tank, 13...Magnetic valve, 15
...Power chamber.

Claims (1)

[Scope of utility model registration request] In a particulate trap filter regeneration device in which a filter device for collecting particulate is provided in the middle of an exhaust pipe, an opening/closing device for opening and closing the exhaust pipe is provided downstream of the filter device, and this opening/closing device is connected to the filter device. The difference between the exhaust gas pressure detected by the exhaust pressure detection means upstream and the exhaust gas pressure detected by the exhaust pressure detection means downstream of the filter device and upstream of the switchgear is greater than a predetermined pressure. 1. A particulate trap filter regeneration device, wherein the particulate trap filter regeneration device is configured to close an exhaust pipe by means of a control circuit.