JPH04109018A - Exhaust gas device for engine - Google Patents

Abstract

PURPOSE:To simplify a device by providing an air supply system for supplying high pressure air to a filter in an exhaust pipe from the direction opposite to an exhaust flow and by controlling first electromagnetic opening/closing valves in this air supply system and second electromagnetic opening/closing valves in the exhaust pipe downstream from the filter so as to regenerate the filter. CONSTITUTION:When one of two filters 4a and 4b is first regenerated and then, the other filter is regenerated, for example, a first electromagnetic valve 13a is opened, a second electromagnetic valve 14a is closed, a first electromagnetic valve 13b is closed, and a second electromagnetic valve 14b is opened, and for a certain period of time (about 5 minutes) high pressure air is injected from a nozzle 11a so as to separate exhaust particulates adhering to the filter 4a. Then, the filter 4b is similarly regenerated. When it is judged that an accelerator switch and a clutch switch are off and an exhaust brake is in operation, the exhaust brake is operated without regenerating the filters 4a and 4b. That is, the first electromagnetic valves 13a and 13b are closed and the second electromagnetic valves 14a and 14b are closed so as to exert the powerful exhaust brake.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an engine exhaust device for exhausting engine exhaust gas, and particularly to an engine exhaust device for exhausting engine exhaust gas, and particularly to a filter for collecting exhaust particulates in the middle of an exhaust pipe. The present invention relates to an exhaust system for an engine having an exhaust system.

[Prior Art] Various exhaust purification devices are being considered for collecting exhaust particulates generated by combustion of diesel engines and releasing only the purified exhaust gas to the atmosphere.

In addition to having an excellent ability to capture exhaust particulates, an exhaust purification device also requires a regeneration function to maintain that ability to collect exhaust particles. A porous filter is provided to collect exhaust particulates, a nozzle is provided to supply compressed air to the filter from the direction opposite to the flow of exhaust scum to separate and drop the exhaust particulates from the filter, and the nozzle and air tank are installed. We have proposed a ``particulate trap regeneration device'' (Utility Application No. 1-124961) in which a solenoid valve is installed in the conduit connecting the two.

[Problem to be solved by the invention] In the proposal, the filter regeneration timing is determined by associating the actual engine rotation speed and engine load with a specific engine rotation speed and engine load. Close the exhaust pipe and open the above solenoid valve,
High-pressure air from the air tank is ejected from the nozzle to regenerate (backwash) the filter.

By the way, an exhaust brake valve operated by an air cylinder is usually provided upstream of the filter in order to generate a large braking force. When the air cylinder is operated, the electromagnetic on-off valve is activated and the exhaust brake valve is turned on. There was a problem that a large amount of air was consumed.

[Means for Solving 5 Problems] The present invention aims to solve the above problems, and includes an air supply system for supplying high-pressure air from a direction opposite to the exhaust flow to a filter interposed in the middle of an exhaust pipe. , a first electromagnetic on-off valve provided in the middle of the air supply system, a second electromagnetic on-off valve provided on the exhaust pipe downstream of the filter, and a second electromagnetic on-off valve provided in the exhaust pipe downstream of the filter; The second solenoid valve is closed and the first solenoid valve is closed when the filter is regenerated.
@A controller configured to open the magnetic on-off valve and close the second electromagnetic valve.

1 Action] During filter regeneration, the controller closes the second electromagnetic on-off valve of the exhaust pipe downstream of the filter, opens the first on-off valve, and opens the air supply system. For this reason, high-pressure air is supplied to the filter from the direction opposite to the exhaust flow, and the exhaust particles adhering to the filter are separated and dropped. On the other hand, in the present invention, the controller closes the first @ solenoid valve and the second solenoid on-off valve to create a large exhaust braking force at the time of exhaust braking. The cost of the device is reduced by sharing the filter, and the air consumption of the air supply system such as the air tank is saved by preventing the filter from being regenerated during exhaust braking.

[Embodiment] A preferred embodiment of the present invention will be described below based on the accompanying drawings.

FIG. 1 shows an engine exhaust system according to the present invention.

As shown in FIG. 1, the exhaust system of the engine 1 is equipped with an exhaust pipe 2 that is once branched into two on the upstream side and then gathered into one on the downstream side, with each exhaust pipe branching section 3a, 3b. To,
Filter devices 4a and 4b are respectively attached.

Each filter device 4a, 4b is constructed as shown in FIG.

As shown in FIG. 2, a filter 7 is provided horizontally on the inner surface of a side plate 6 in a filter casing 5 formed into a box shape that is elongated in the flow direction of exhaust gas. An exhaust gas introducing chamber 8 whose volume gradually decreases toward the downstream side of the exhaust gas is formed in the upper part of the filter, and a particulate collection chamber 9 whose volume gradually increases toward the downstream side is formed at the lower part of the filter. is formed. The filter 7 is made of an air-permeable ceramic porous material in order to attach and collect exhaust particulates and to efficiently pass and discharge exhaust residue purified by the filter. Vertical through-holes 10 are formed in the filter tube at intervals in the width direction and the longitudinal direction to communicate and connect the exhaust gas introduction chamber 8 and the particulate replenishment chamber 9.

In other words, the inner circumferential surface of the through-hole 10 can be effectively used as a filter wall for exhaust gas particles. Note that in order to improve the air permeability of the filter, the filter 7 around each through hole 10 may be formed hollow. In the present invention, the horizontal cross section of each through hole 10 is formed in a circular shape. There is.

With this configuration, exhaust particulates in the exhaust gas adhere to the inner peripheral surface of the through hole 10, and purified and clean exhaust gas is discharged into the atmosphere through the exhaust pipe 2.

By the way, in order to regenerate each filter device 1f4a, 4b and continue the collection performance of the filter 7, the exhaust filter 7
Immediately downstream of the device, as shown in Fig. 1, high-pressure air is supplied with the tip facing the filter in order to use the pressure waves of the high-pressure air to separate the exhaust particulates from the inner peripheral surface of the through-hole 10. Nozzles 11a and 11b are respectively attached for this purpose. These nozzles Ila and llb are connected to the air supply tube 12.
a.

12b and first electromagnetic on-off valves 13a, 13b, respectively, are connected to the air tank 14. In addition, each exhaust pipe branch part 3a, 3b has a
Second electromagnetic on-off valves 14a, 14b are attached to open and close the exhaust branch portions 3a, 3b.

Now, a controller 15 is attached to these first @magnetic on-off valves 13a, 13b=second electromagnetic on-off valves 14a, 14b in order to control opening and closing of these.

The input section of the controller 15 is the 0N-OFF signal of the exhaust plexi switch and the 0N-OFF signal of the accelerator switch.
F signal and the ON-OFF signal of the clutch switch are electrically connected to each other, and the output section is connected to the first. Second
It is electrically configured to output an opening/closing signal to the electromagnetic opening/closing valves 13a, 13b, 14a, and 14b.

The control section of the controller 15 is configured to execute the following control based on the input signal.

As shown in the flowchart of FIG. 3, the controller 15 passes through the start 16, and in step 17 determines whether the exhaust brake switch is ON or OFF, in step 18 the accelerator switch is ON or OFF, and in step 19 the clutch switch is Determine whether it is ON or OFF. If it is determined in steps 18 and 19 that the accelerator switch and the clutch switch are OFF, it is determined that the exhaust brake is activated, and the exhaust brake is activated without regenerating the filter devices 4a and 4b. This flow, step 21
If the accelerator switch or clutch clutch is turned ON before proceeding to Step 22, the exhaust brake control is canceled as the exhaust brake has been released.
Proceed to and perform filter regeneration. In step 21, the first electromagnetic opening/closing 13a is activated to operate the exhaust brake.

13b is closed to cut off the supply of high pressure air to the nozzles lla and llb, and at the same time, the second electromagnetic on-off valves 14a and 14b are closed.
close to activate the exhaust brake. As a result, a strong exhaust brake acts on the engine 1 and the engine 1 is braked.

Filter regeneration is basically possible by opening the on-off valves 14a and 14b and closing the second on-off valves 14a and b, but this requires exhaust gas to be discharged while the engine 1 is running. In order to avoid an increase in the load due to exhaust gas, in the present invention, one of the two filters 4a and 4b is regenerated first, and after that regeneration, the other filter is regenerated.

For example, open the first solenoid valve 13a and close the second solenoid valve 14a,
The first solenoid valve 13b is closed and the second solenoid valve 14b is opened to perform filter regeneration of one filter device 4a for a certain period of time (approximately 5 minutes), and after that time, the first solenoid valve 13b is opened and the second solenoid valve 14b is opened. Close the second solenoid valve 14b, close the first solenoid valve 13a, and close the second solenoid valve 13a.
The magnetic valve 14a is opened to perform filter regeneration of the other filter device 4b.

Note that filter regeneration is performed by monitoring the engine rotation speed and engine load, that is, similar to Utility Application No. 1-124961, by monitoring the engine load at a specific engine rotation speed,
Perform filter regeneration when the load is large.

In this way, the present invention reduces equipment costs by using the exhaust brake valve and the on-off valve for filter regeneration in common, and also reduces the consumption of high-pressure air in the air tank by allowing filter regeneration to be performed at times other than during exhaust braking. We try to save as much as possible.

[Effects of the Invention] As is clear from the above explanation, the present invention provides the following excellent effects.

(1) The consumption of high-pressure air stored in the air tank can be saved to regenerate the filter device and perform exhaust braking.

(2) An inexpensive engine exhaust system can be provided.

[Brief explanation of the drawing]

Figure 1 shows an engine exhaust system according to the present invention! FIG. 2 is a sectional view of the filter device; FIG. 3 is a sectional view of the filter device;
The figure is a flowchart showing the control contents of the controller. In the figure, 1 is an engine, 2 is an exhaust pipe, 7 is a filter, and 13a. 3b is number 1! A magnetic on-off valve, a 14b is a second electromagnetic on-off valve, and 15 is a control. Patent applicant Nobuo Kinutani, patent attorney representing Isuda Motors Co., Ltd.

Claims (1)

[Claims] 1. An air supply system for supplying high-pressure air from a direction opposite to the exhaust flow to a filter installed in the middle of the exhaust pipe, a first electromagnetic on-off valve installed in the middle of the air supply system, and a filter installed in the middle of the exhaust pipe. A second electromagnetic on-off valve provided in the downstream exhaust pipe, and the first and second electromagnetic valves are closed during exhaust braking, and the first electromagnetic on-off valve is opened and the second electromagnetic valve is closed during filter regeneration. An exhaust system for an engine, comprising: a controller configured with a controller.