KR101886903B1 - Method of Treatmenting Exhaust in Working Equipment - Google Patents

Abstract

A method of treating an exhaust gas of a working machine, the method comprising the steps of: controlling the engine, Calculating a DPF differential pressure value from the DPF differential pressure signal from the gas processing device, and transmitting the DPF differential pressure value to the control unit; The control unit verifying the DPF level step by the DPF differential pressure value; Determining whether the control unit corresponds to an automatic DPF regeneration condition or a forced DPF regeneration condition by the verified DPF level step; And the control unit activates the control valve at a time point from a DPF level step corresponding to the automatic DPF regeneration condition to a DPF level step corresponding to the forced DPF regeneration condition to apply a load to the engine, To be automatically performed.
The exhaust gas processing method of the present invention increases the load applied to the engine at the time of shifting from the automatic DPF regeneration condition to the forced DPF regeneration condition due to the neutralization of the gear or the decrease of the engine load during the operation, The automatic DPF regeneration condition can be maintained at all times during the operation of the working machine, so that the operator does not have to perform the forced DPF regeneration and the working efficiency can be improved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method for treating an exhaust gas of a working machine.

Due to the diversity of work to be done in the industrial field, the working machine can be divided into excavation equipment, loading equipment, conveying equipment, loading equipment, compaction equipment, foundation equipment, etc. Specifically, It is a concept that includes equipment of the kind.

In general, a forklift, a working machine, is a device for lifting or lowering a relatively heavy load or transporting the load in a limited working environment to a desired position.

These forklifts are divided into engine forklifts and electric forklifts. Engine forklift trucks are widely used in the outdoor area, while electric forklift trucks are often used in the indoor area due to low smoke and noise.

In addition, the forklift is classified into a standard forklift, in which the mast assembly is fixed to the vehicle body, and a reach type forklift, in which the mast assembly moves back and forth with respect to the vehicle body along the rich lag. The engine type is equipped with an engine, and the electric type and the rich type forklift are so-called electric forklifts equipped with an electric motor and a battery for supplying electric power thereto.

BACKGROUND ART A forklift equipped with a diesel engine is equipped with a diesel engine post-treatment device (DOC) and a diesel particulate filter (DOC) An exhaust gas aftertreatment apparatus in which a DPF (Diesel Particulate Filter) is combined with a DPF is widely used in the art.

The exhaust gas purification of a diesel engine mainly deals with nitrogen oxides (NOx) and particulate matter (PM, various particulate harmful substances including soot), which are adsorbed by the DOC or DPF of the exhaust gas after- So that it is purified.

Among them, in particular, DPF collects particulate matter (carbon particulates) discharged from a diesel engine with a filter, and burns it (regenerates) the particulate matter. Therefore, it is known as an excellent exhaust gas post-treatment device in terms of performance.

DPF regeneration includes automatic regeneration performed when a predetermined condition is satisfied and forced regeneration performed forcibly regeneration by an operator's intention.

For normal automobile vehicles, forced DPF regeneration is performed only when it is judged to be safe by receiving the gear neutral / vehicle speed / parking brake signal.

On the other hand, since the forklift, which is a working machine, is provided with a working machine in addition to the driving function, it is necessary to prepare for the risk of safety accident when forcibly regenerating the DPF. That is, when the forced DPF regeneration is performed, since the number of revolutions of the engine is higher than in a normal situation, the operation of the machine during the DPF regeneration is very dangerous. have.

Korean Patent Publication No. 10-2012-0052510 (Publication date: May 24, 2012) Korean Patent Publication No. 10-2014-0012260 (published on March 03, 2014)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art and it is an object of the present invention to provide an automatic DPF regeneration control apparatus and method capable of always maintaining an automatic DPF regeneration condition And a method for treating exhaust gas of a machine.

A method for processing an exhaust gas of a working machine according to an aspect of the present invention is a method for processing exhaust gas of a working machine including a control unit, a control valve, an engine control unit, an engine, and an exhaust gas processing unit, Calculating a DPF differential pressure value from the DPF differential pressure signal from the exhaust gas processing device, and transmitting the DPF differential pressure value to the control unit; The control unit verifying the DPF level step by the DPF differential pressure value; Determining whether the control unit corresponds to an automatic DPF regeneration condition or a forced DPF regeneration condition by the verified DPF level step; And the control unit activates the control valve at a time point from a DPF level step corresponding to the automatic DPF regeneration condition to a DPF level step corresponding to the forced DPF regeneration condition to apply a load to the engine, To be automatically performed.

Specifically, the working machine may be a forklift.

Specifically, the exhaust gas treatment apparatus includes a DOC for removing carbon monoxide and hydrocarbons contained in the exhaust gas discharged from the engine, and the DPF for filtering particulate matter contained in the exhaust gas, And a differential pressure sensor for sensing the differential pressure between the upstream and downstream sides of the filtered particulate matter.

Specifically, the DPF level step may be divided into a level 0 step, a level 1 step, a level 2 step, a level 3 step, a level 4 step, and a level 5 step as the DPF differential pressure value increases.

Specifically, the level 0 step is a state in which the particulate matter is not present in the DPF, and the level 1 step and the level 2 step are steps in which the particulate matter exists in the DPF, Wherein the DPF is in a state capable of burning the particulate matter in an automatic DPF regeneration condition in which regeneration of the DPF is automatically performed, wherein the particulate matter exists in the DPF and the level 3 stage and the level 4 stage, The DPF can be regenerated under the automatic DPF regeneration condition and the forced DPF regeneration condition, and the level 5 is a state in which the particulate matter is to be burned in a forced DPF regeneration condition in which regeneration of the DPF is forcibly performed in a stopped and parked state. The DPF may be detached from the DPF.

Specifically, in the step of determining whether the automatic DPF regeneration condition or the forced DPF regeneration condition is satisfied by the identified DPF level step, the control unit automatically determines whether the DPF regeneration condition is satisfied The regeneration of the DPF can be forcibly performed in a state where the working machine is parked.

Specifically, the automatic DPF regeneration condition is such that when the temperature of the exhaust gas rises to 250 ° C or more based on the inlet of the DOC, the DOC reacts and exhaust gas of 550 ° C to 600 ° C, which is the regeneration reference temperature of the DPF, The exhaust gas temperature is raised in the exhaust gas processing apparatus so that particulate matter accumulated in the DPF can be automatically burned, and can be automatically performed while the working machine is in operation.

Specifically, the control unit activates the control valve at a time point from a DPF level step corresponding to the automatic DPF regeneration condition to a DPF level step corresponding to the forced DPF regeneration condition to apply a load to the engine, The load can be applied in real time to the engine so that the automatic DPF regeneration condition is satisfied in the exhaust gas processing apparatus.

The exhaust gas processing method of the present invention increases the load applied to the engine at the time of shifting from the automatic DPF regeneration condition to the forced DPF regeneration condition due to the neutralization of the gear or the decrease of the engine load during the operation, The automatic DPF regeneration condition can be maintained at all times during the operation of the working machine, so that the operator does not have to perform the forced DPF regeneration and the working efficiency can be improved.

FIG. 1 is a flowchart for explaining a method of treating an exhaust gas of a working machine according to an embodiment of the present invention.
2 is a configuration diagram of an exhaust gas processing system of a working machine for explaining a method for processing exhaust gas of a working machine according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flow chart for explaining a method of treating exhaust gas of a working machine according to an embodiment of the present invention. FIG. 2 is a view showing a working machine for explaining a method of treating exhaust gas of a working machine according to an embodiment of the present invention. Fig. 2 is a block diagram of an exhaust gas processing system.

A control valve 200, an engine control unit 300, an engine 400, and a control unit 200. The control unit 100 controls the operation of the engine 400, And an exhaust gas processing device (500), the engine control device (300) receives the DPF differential pressure signal from the exhaust gas processing device (500) and calculates a DPF differential pressure value, The control unit 100 determines whether or not the automatic DPF regeneration condition or the automatic DPF regeneration condition is satisfied by checking the DPF level step (S120) (S130) of determining whether the DPF regeneration condition is satisfied, and when the control unit 100 determines that the DPF regeneration condition is satisfied, 200 is operated to apply a load to the engine 400, and the regeneration of the DPF 520 And a step (S140) to ensure automatic.

In step S110, the engine control device 300 receives the DPF differential pressure signal from the exhaust gas processing device 500, calculates the DPF differential pressure value, and transmits it to the control section 100. [

The exhaust gas processing apparatus 500 of the working machine is installed on an exhaust line 410 connected to an engine 400 of a forklift which is a working machine and includes a control unit 100, a control valve 200, Together with the exhaust gas treatment system 300, constitute the exhaust gas treatment system 1.

The exhaust gas treatment apparatus 500 includes a DOC 510 for removing carbon monoxide (CO) and hydrocarbons (HC) contained in the exhaust gas discharged from the engine 400, particulate matter (PM) contained in the exhaust gas. And a DPF 520 for filtering various particulate harmful substances including soot. The DPF 520 may be equipped with a differential pressure sensor (not shown) for sensing the pressure difference between the front and rear sides by the filtered particulate matter.

In the above, the DPF differential pressure value can be obtained by sensing the differential pressure across the DPF 520 using a differential pressure sensor or the like.

When the working machine is a forklift, the control unit 100 may be an MCU, the control valve 200 may be a hydraulic solenoid valve, and the engine control unit 300 may be an ECU.

In step S120, the control section 100 confirms the DPF level step by the DPF differential pressure value.

The DPF level step can be divided into a level 0 step, a level 1 step, a level 2 step, a level 3 step, a level 4 step, and a level 5 step as the DPF differential pressure value increases. The multi-level level may be divided according to the amount of particulate matter present in the DPF 520, and may vary depending on the type, performance, etc. of the working machine.

Level 0 may be defined as a state in which particulate matter is not present in the DPF 520. In this case, there is no need to regenerate the DPF 520, so that the automatic DPF regeneration condition or the forced DPF regeneration condition is satisfied The working machine may be operated in a steady state without applying an additional load to the engine 400. [

The level 1 and level 2 stages are stages in which particulate matter exists in the DPF 520 but can be burned in an automatic DPF regeneration condition in which regeneration of the DPF 520 is automatically performed while the working machine is working .

The level 3 and level 4 stages are such that particulate matter that can not be burned (can not regenerate) particulate matter present in the DPF 520 due to the automatic DPF regeneration condition is heavily adhered to the DPF 520, It can be defined as a stage where the particulate matter is to be burned under the forced DPF regeneration condition in which the operation is stopped and the regeneration of the DPF 520 is forcibly performed in the parked state.

Level 5 may be defined as a stage in which the DPF 520 can not be regenerated under the automatic DPF regeneration condition as well as the forced DPF regeneration condition and the DPF 520 must be removed.

The automatic DPF regeneration condition is such that when the exhaust gas temperature rises to 250 ° C or more based on the inlet of the DOC 510, the DOC 510 reacts and the exhaust gas at 550 ° C to 600 ° C, which is the regeneration reference temperature of the DPF 520, The exhaust gas processing apparatus 500 can automatically raise the exhaust gas temperature so that the particulate matter accumulated in the DPF 520 can be automatically burned in the DPF 520. [ Lt; / RTI > Such an automatic DPF regeneration condition can be satisfied, for example, during running of the work machine in which the load of the engine 400 is increased.

However, since the forced DPF regeneration condition requires a larger load to be applied to the engine 400 than the automatic DPF regeneration condition, if the regeneration of the DPF 520 is forcibly performed during the operation, the engine 400 is overloaded, 400), it should be done while parking the work machine. This forced DPF regeneration condition may occur, for example, when the load of the engine 400 is reduced, for example, in the gear neutral state of the work machine. When the working machine is a forklift, the forklift is mostly carried out when the work is in the gear neutral state, so that it is often necessary to forcibly regenerate the DPF 520.

In step S130, the control unit 100 judges whether it corresponds to the automatic DPF regeneration condition or the forced DPF regeneration condition by the confirmed DPF level step.

When the DPF level step corresponds to the automatic DPF regeneration condition as the level 1 step or the level 2 step, the regeneration of the DPF 520 is performed automatically during the operation of the working machine, as described above, When the DPF level step corresponds to the forced DPF regeneration condition as the level 3 step or the level 4 step, the regeneration of the DPF 520 must be performed while the working machine is parked, as described above, It is necessary to determine whether the DPF level step corresponds to the automatic DPF regeneration condition or the forced DPF regeneration condition so that the operation efficiency of the working machine can be improved by performing step S140 to be described later.

In other words, if the control unit 100 determines that the DPF level step already corresponds to the forced DPF regeneration condition, the DPF 520 is forced to be regenerated in a state where the working machine is parked, without performing step S140 to be described later This is because the load applied to the engine 400 in step S140 to be described later must be applied to the engine 400 as an overload corresponding to the forced DPF regeneration condition described above.

In step S140, the control unit 100 operates the control valve 200 at a time point from the DPF level step corresponding to the automatic DPF regeneration condition to the DPF level step corresponding to the forced DPF regeneration condition, So that the DPF 520 is automatically regenerated.

In step S140, the engine 400 can be loaded with the load in real time so as to meet the automatic DPF regeneration condition in the exhaust gas processing apparatus 500. [

In the above, the engine 400 is supplied with the load from the DPF level step corresponding to the automatic DPF regeneration condition to the DPF level step corresponding to the forced DPF regeneration condition, The regeneration of the DPF 520 can be performed automatically at all times during the operation of the work machine in a state in which the large load is not applied and the engine 400 is not overloaded.

As described above, according to the present embodiment, the load imposed on the engine 400 is increased at the time of shifting from the automatic DPF regeneration condition to the forced DPF regeneration condition for reasons such as gear neutralization or engine load reduction during the operation, The automatic DPF regeneration condition can be maintained at all times during the operation of the working machine, so that the operator does not have to perform the forced DPF regeneration and the working efficiency can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification and the modification are possible.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1: Exhaust gas treatment system 100:
200: control valve 300: engine control device
400: engine 410: exhaust line
500: Exhaust gas treatment device 510: DOC
520: DPF

Claims (8)

A method of treating an exhaust gas of a working machine including a control unit, a control valve, an engine control unit, an engine, and an exhaust gas processing unit,
The engine control device receives a DPF differential pressure signal from the exhaust gas processing device and calculates a DPF differential pressure value and transmits the DPF differential pressure value to the control part;
The control unit verifying the DPF level step by the DPF differential pressure value;
Determining whether the control unit corresponds to an automatic DPF regeneration condition or a forced DPF regeneration condition by the verified DPF level step; And
The control unit operates the control valve at a time point from the DPF level step corresponding to the automatic DPF regeneration condition to the DPF level step corresponding to the forced DPF regeneration condition to apply a load to the engine, Wherein the exhaust gas is exhausted from the exhaust pipe. The work machine according to claim 1,
Wherein the exhaust gas is a forklift. The exhaust gas treatment system according to claim 1,
A DOC for removing carbon monoxide and hydrocarbons contained in the exhaust gas discharged from the engine, and the DPF for filtering particulate matter contained in the exhaust gas,
Wherein the DPF is provided with a differential pressure sensor for detecting the pressure difference between the front and rear sides by the filtered particulate matter. 4. The method of claim 3, wherein the DPF level step comprises:
The level 1 stage, the level 2 stage, the level 3 stage, the level 4 stage, and the level 5 stage as the DPF differential pressure value increases. 5. The method of claim 4,
Wherein the level 0 is a state in which the particulate matter is not present in the DPF,
The level 1 and the level 2 are states in which the particulate matter exists in the DPF and the particulate matter can be burned in an automatic DPF regeneration condition in which regeneration of the DPF is automatically performed while the working machine is working ,
Wherein the level 3 and level 4 steps are performed so that the particulate matter exists in the DPF and the particulate matter is burned in a forced DPF regeneration condition in which the operation of the working machine is stopped and the regeneration of the DPF is forced in a parked state Lt; / RTI >
Wherein the level 5 is a state in which the DPF can not be regenerated under the automatic DPF regeneration condition and the forced DPF regeneration condition so that the DPF must be removed. 6. The method according to claim 5, wherein, in the step of determining whether the control unit corresponds to the automatic DPF regeneration condition or the forced DPF regeneration condition by the verified DPF level step,
Wherein the step of forcibly regenerating the DPF in a state where the working machine is parked is performed without performing a step of automatically regenerating the DPF when it is determined that the DPF regeneration condition is satisfied A method of treating an exhaust gas of a machine. 6. The automatic DPF regeneration system according to claim 5,
When the temperature of the exhaust gas rises to 250 ° C or higher based on the entrance of the DOC, the DOC reacts and exhaust gas having a regeneration reference temperature of 550 ° C to 600 ° C enters the DPF and accumulates particulate matter Wherein the temperature of the exhaust gas is raised in the exhaust gas processing device so that the exhaust gas can be automatically burned, and is automatically performed during the operation of the working machine. 8. The method of claim 7, wherein the control unit operates the control valve at a time point from a DPF level step corresponding to the automatic DPF regeneration condition to a DPF level step corresponding to the forced DPF regeneration condition, In the step of automatically reproducing the DPF,
Wherein a load is applied to the engine in real time so as to satisfy the automatic DPF regeneration condition in the exhaust gas processing apparatus.

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