KR101755934B1 - A method for protecting dpf in dti conditions and an apparastus therefor - Google Patents

Abstract

The present invention relates to a method and apparatus for protecting a DPF under DTI conditions. A method of protecting a DPF in a DTI condition according to an embodiment of the present invention includes: initiating playback of a DPF (DIESEL PARTICULATE FILTER) (S100); Determining whether the vehicle has entered a DRO (DROP TO IDLE) condition (S200); (S300) of measuring the temperature change amount (x) per unit time at the measuring unit at the rear end of the DPF when the vehicle enters the DTI condition; (S400) of determining whether the measured temperature variation amount (x) is equal to or greater than a predetermined first reference temperature variation amount (a) and less than a predetermined second reference temperature variation amount (b); And controlling the RPM of the engine according to a result of the determining step (S400). According to the present invention, it is possible to prevent the DPF breakage due to abnormal regeneration (UNCONTROLLED BURNING, a phenomenon in which the DPF internal temperature rises rapidly) without decreasing the regeneration efficiency and deteriorating the fuel efficiency.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for protecting a DPF in a DTI condition,

The present invention relates to a method and apparatus for protecting a DPF in a DTI condition, and more particularly, to a method and apparatus for preventing a DPF from being damaged due to a sudden temperature rise inside the DPF under a DTI condition.

The DPF (DIESEL PARTICULATE FILTER) is a device that collects PM (PARTICULATE MATTER) contained in the exhaust gas and prevents PM from being contained in the exhaust gas discharged into the atmosphere. In addition, the DPF recovers the trapping ability by burning and removing deposited PM (including SOOT), which is generally referred to as DPF regeneration. In order to regenerate the DPF, the internal temperature of the DPF must be raised to a certain level, and the post-fuel injection is performed.

However, when the engine enters the DRO (DROP TO IDLE) condition during the regeneration of the DPF (for example, when the vehicle is stopped due to a signal waiting during driving of the vehicle), the engine RPM is reduced to a predetermined idle RPM, . Therefore, unstable regeneration (UNCONTROLLED BURNING, a phenomenon in which the DPF internal temperature rises sharply) occurs in the regenerating DPF, which exceeds the limit temperature of the DPF (for example, 1200 degrees Celsius) . FIG. 1 is a view for explaining a problem of the prior art. Referring to FIG. 1, it can be seen that the temperature inside the DPF sharply increases when the DTI condition is entered during DPF regeneration.

In order to prevent the above problems, the DPF is protected by reducing the regeneration temperature of the DPF or decreasing the amount of injected HC (HYDROCARBON, i.e., fuel) injected backwards. However, the conventional technology as described above has a problem of reducing the regeneration efficiency and deteriorating the fuel efficiency.

Japanese Patent Application Laid-Open No. 10-2011-0062127 (2077.06.10)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for protecting a DPF under DTI conditions by actively controlling the engine RPM according to the amount of temperature change per unit time in the DPF will be.

A method of protecting a DPF in a DTI condition according to an embodiment of the present invention includes: initiating playback of a DPF (DIESEL PARTICULATE FILTER) (S100); Determining whether the vehicle has entered a DRO (DROP TO IDLE) condition (S200); (S300) of measuring the temperature change amount (x) per unit time at the measuring unit at the rear end of the DPF when the vehicle enters the DTI condition; (S400) of determining whether the measured temperature variation amount (x) is equal to or greater than a predetermined first reference temperature variation amount (a) and less than a predetermined second reference temperature variation amount (b); And controlling the RPM of the engine according to a result of the determining step (S400).

If it is determined in step S400 that the temperature variation amount x is less than the first reference temperature variation amount a, the controlling step S500 may maintain the RPM of the engine at a predetermined idle RPM And a first control step (S510).

If it is determined in step S400 that the temperature variation amount x is equal to or greater than the first reference temperature variation amount a and less than the second reference temperature variation amount b And a second control step (S520) of raising the RPM of the engine to a predetermined first RPM.

And the first RPM is equal to or greater than a predetermined idle RPM.

If it is determined in step S400 that the temperature change amount x is equal to or greater than the second reference temperature change amount b, the controlling step S500 may be configured to change the RPM of the engine to a predetermined second RPM And a third control step (S520) of raising the temperature of the gas.

And the second RPM is equal to or higher than a predetermined first RPM.

The method for protecting the DPF in the DTI condition may include repeating the determining step S200 to the controlling step S500 until the DPF regeneration is terminated or the DTI condition is escaped, ; And

A method of protecting a DPF in a DTI condition according to another embodiment of the present invention includes the steps of: initiating regeneration of a DPF (DIESEL PARTICULATE FILTER) (S100 '); Determining whether the vehicle has entered a DRO (TO IDLE) condition (S200 '); A step S300 'of measuring the amount of temperature change per unit time (x`) at the measuring unit at the downstream end of the DPF when the vehicle enters the DRO (TO IDLE) condition; (S400 ') controlling the engine RPM of the vehicle to be the reference engine RPM corresponding to the temperature variation amount (x') according to the reference engine RPM map (MAP) and the previously stored DPF temperature variation amount (x`); .

The method of protecting the DPF in the DTI condition may include repeating the determining step S200 'through the controlling step S400' until the regeneration of the DPF is terminated or until the DTI condition is escaped (S500 ').

The storage medium according to another embodiment of the present invention stores the method of protecting the DPF under the DTI condition.

The apparatus for protecting a DPF in a DTI condition according to another embodiment of the present invention includes the storage medium 100; A measurement unit 200 for measuring a temperature change amount per unit time at the rear end of the DPF; And a control unit (400) for controlling the RPM of the engine (300) according to a method of protecting the DPF in the DTI condition stored in the storage medium (100) using the temperature variation measured by the measuring unit (200) .

As described above, according to the present invention, it is possible to prevent the DPF breakage due to abnormal regeneration (UNCONTROLLED BURNING, a phenomenon in which the DPF internal temperature rises rapidly) without decreasing the regeneration efficiency and deteriorating the fuel efficiency.

1 is a view for explaining a problem of the prior art;
2 is a flowchart of a method of protecting a regenerating DPF according to an embodiment of the present invention.
3 is a flowchart of a method of protecting a regenerating DPF according to another embodiment of the present invention.
4 is a block diagram of a protection device for a regenerating DPF according to another embodiment of the present invention.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term to describe its invention in the best way And should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents It should be understood that water and variations may be present. 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.

2 is a flowchart of a method of protecting a DPF under reproduction according to an embodiment of the present invention. Referring to FIG. 2, a method of protecting a regenerating DPF according to an exemplary embodiment of the present invention includes: initiating playback of a DPF (DIESEL PARTICULATE FILTER) (S100); Determining whether the vehicle has entered a DRO (DROP TO IDLE) condition (S200); (S300) a temperature change amount (x) per unit time at a temperature sensor at the rear end of the DPF when the vehicle enters the DTI condition; (S400) of determining whether the measured temperature variation amount (x) is equal to or greater than a predetermined first reference temperature variation amount (a) and less than a predetermined second reference temperature variation amount (b); And controlling the RPM of the engine according to a result of the determining step (S400).

In the step of starting the regeneration (S100), HC (HYDROCARBON) is added to the front of the DOC (DIESEL OXIDATION CATALYST) in order to recover the DPF capturing ability by burning off the PM when the PM accumulated in the DPF is equal to or more than a predetermined reference amount And raising the DPF internal temperature to a preset regeneration temperature. The predetermined reference amount and the predetermined regeneration temperature may be set differently according to the type of the vehicle or the like.

In the determining step S200, it is determined whether the engine RPM is a predetermined idle RPM. The predetermined idle RPM may be set differently according to the type of vehicle.

In the measuring step (S300), the amount of temperature change (x) per unit time in the DPF is measured. The temperature change amount (x) per unit time is an index for determining whether or not an abnormal regeneration inside the regenerating DPF occurs under the DTI condition.

일 수 있고, 상기 기설정된 제 2 기준 온도변화량(b)은

일 수 있으나, 반드시 이에 한정되는 것은 아니고, 차량의 종류, DPF의 내구온도 등에 따라 달리 설정될 수 있다.In the determining step S400, it is determined whether the measured temperature change amount x is greater than a predetermined first reference temperature change amount a and less than a predetermined second reference temperature change amount b. That is, the predetermined first reference temperature change amount a becomes a criterion for discriminating the abnormal regeneration, and the predetermined second reference temperature change amount b is a criterion in which the degree of abnormal regeneration is excessive, do. The predetermined first reference temperature change amount (a) and the predetermined second reference temperature change amount (b) may be empirically measured values. Further, the predetermined first reference temperature change amount (a)

, And the predetermined second reference temperature change amount (b) may be

However, the present invention is not limited to this, and may be set differently depending on the type of vehicle, the durability temperature of the DPF, and the like.

The controlling step S500 includes a first controlling step S510, a second controlling step S520 and a third controlling step S520. If it is determined in step S400 that the measured temperature change amount x is less than the first reference temperature change amount a, the first control step S510 may further include: . That is, since the measured temperature change amount (x) is less than the first reference temperature change amount (a), no abnormal regeneration has occurred. Therefore, in the DTI condition, the RPM of the engine is maintained at a predetermined idle RPM. The predetermined idle RPM may be set to 800 RPM, but is not limited thereto and can be set differently depending on the type of vehicle and the like.

The second control step S520 may further include determining whether the measured temperature change amount x is greater than the first reference temperature change amount a and less than the second reference temperature change amount b in the determining step S400 , Raising the RPM of the engine to a predetermined first RPM. That is, since the measured temperature change amount x is equal to or greater than the first reference temperature variation amount a and less than the second reference temperature variation amount b, abnormal regeneration has occurred. Accordingly, the RPM of the engine is increased to a predetermined first RPM to increase the inflow of the fresh air. Accordingly, since the DPF is cooled, it is possible to prevent the DPF from being damaged due to abnormal regeneration.

Here, the first RPM is equal to or greater than a predetermined idle RPM. That is, by driving the engine with the first RPM higher than the idle RPM in the DTI state, the DPF is cooled by introducing more than the amount of the fresh air introduced from the idle RPM. Also, the first RPM may be an RPM increased by 100 RPM from the predetermined idle RPM, and the inflow amount of the fresh air may be set to increase by about 5% every 100 RPM, but the present invention is not limited thereto. Can be set differently.

If it is determined in step S400 that the measured temperature change amount x is equal to or greater than the second reference temperature change amount b, the third control step S520 may further include: 0.0 > RPM. ≪ / RTI > That is, since the measured temperature change amount (x) is equal to or greater than the second reference temperature change amount (b), an abnormal regeneration occurs in which abrupt DPF damage may occur. Therefore, the RPM of the engine is increased to a predetermined second RPM, and the inflow of the fresh air is greatly increased. As a result, the DPF is quickly cooled, and therefore the DPF breakage due to the abnormal regeneration can be prevented.

In this case, the second RPM is equal to or higher than a predetermined first RPM. That is, by driving the engine with the second RPM which is higher than the first RPM in the DTI state, the DPF is cooled by introducing more than the amount of the fresh air introduced from the first RPM. Also, the second RPM may be RPM increased by 100 RPM from the first RPM, and the inflow amount of the fresh air may be set to increase by about 5% per 100 RPM. However, the present invention is not limited thereto. Can be set differently.

The repeating step S600 repeats the determining step S200 to the controlling step S500 until the reproduction of the DPF is terminated or until the DTI condition is escaped. That is, abnormal reproduction may occur at any time during regeneration of the DPF in the DTI condition, so that the above-mentioned determining step (S200) to the controlling step (S500) are repeatedly performed to prevent the DPF breakage due to the abnormal regeneration.

3 is a flow chart of a method of protecting a regenerating DPF according to another embodiment of the present invention. Referring to FIG. 3, a method of protecting a regenerating DPF according to another embodiment of the present invention includes: initiating regeneration of a DPF (DIESEL PARTICULATE FILTER) (S100 '); Determining whether the vehicle has entered a DRO (TO IDLE) condition (S200 '); A step S300 'of measuring the amount of temperature change per unit time (x`) at the measuring unit at the downstream end of the DPF when the vehicle enters the DRO (TO IDLE) condition; And controlling the engine RPM of the vehicle to be the reference engine RPM corresponding to the measured temperature change amount (x ') in accordance with the reference engine RPM map (MAP) .

The protecting method of the regenerating DPF may include repeating the determining step S200 'to the controlling step S400' until the regeneration of the DPF is completed or until the DTI condition is escaped &Quot;). ≪ / RTI >

The step of starting (S100`), the step of determining (S200`), the step of measuring S300` and the step of repeating S500` may be started in step S100, ), The measuring step S300, and the repeating step S600, and therefore, a description thereof will be omitted.

The controlling step S400` controls the engine RPM of the vehicle so as to be the reference engine RPM corresponding to the measured temperature variation amount x` according to the DPF temperature variation amount x ' . The pre-stored DPF temperature change amount (x ') - the reference engine RPM map (MAP) may be measured experimentally and stored as an optimal engine RPM for DPF cooling according to the temperature change amount (x'). That is, the controlling step S500 discriminates the temperature change amount x from a plurality of sections, and controls the engine RPM stored in advance for each section. In contrast, in the controlling step S400 ', the control is performed using the pre-stored engine RPM corresponding to each temperature variation amount x', thereby preventing the DPF from being damaged more effectively due to the occurrence of abnormal regeneration .

4 is a block diagram of a protection apparatus for a regenerating DPF according to another embodiment of the present invention. Referring to FIG. 4, the apparatus for protecting a DPF in the DTI condition includes a storage medium 100 storing a method of protecting the DPF under the DTI condition; A measurement unit 200 for measuring a temperature change amount per unit time at the rear end of the DPF; And a control unit (400) for controlling the RPM of the engine (300) according to a method of protecting the DPF in the DTI condition stored in the storage medium (100) using the temperature variation measured by the measuring unit (200) .

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, as claimed, and will be fully understood by those of ordinary skill in the art. The present invention is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and variations are possible within the scope of the present invention, and it is obvious that those parts easily changeable by those skilled in the art are included in the scope of the present invention .

100 storage medium
200 measuring unit
300 engine
400 controller

Claims (11)

(S100) of starting reproduction of a DPF (DIESEL PARTICULATE FILTER);
Determining whether the vehicle has entered a DRO (DROP TO IDLE) condition (S200);
(S300) of measuring a temperature change amount (x) per unit time in the measurement unit (200) at the rear end of the DPF when the vehicle enters the DTI condition;
(S400) of determining whether the measured temperature variation amount (x) is equal to or greater than a predetermined first reference temperature variation amount (a) and less than a predetermined second reference temperature variation amount (b); And
(S500) controlling the RPM of the engine 300 according to the result of the determining step (S400)
If it is determined in step S400 that the temperature change amount x is equal to or greater than the second reference temperature change amount b, the controlling step S500 may further include the step of: A third control step (S520) of raising to 2 RPM;
Lt; RTI ID = 0.0 > DTI < / RTI > condition. The method according to claim 1,
If it is determined in step S400 that the temperature change amount x is less than the first reference temperature change amount a, the controlling step S500 may further include the step of: A first control step (S510) of maintaining the voltage at the RPM;
Lt; RTI ID = 0.0 > DTI < / RTI > condition. The method according to claim 1,
If it is determined in step S400 that the temperature variation amount x is equal to or greater than the first reference temperature variation amount a and less than the second reference temperature variation amount b A second control step (S520) of raising the RPM of the engine (300) to a predetermined first RPM;
Lt; RTI ID = 0.0 > DTI < / RTI > condition. The method of claim 3,
Wherein the first RPM is equal to or greater than a predetermined idle RPM. delete The method according to claim 1,
Wherein the second RPM is equal to or greater than a predetermined first RPM. The method according to claim 1,
(S600) of repeating the determining step (S200) to the controlling step (S500) until the reproduction of the DPF ends or the DTI condition is escaped;
Lt; RTI ID = 0.0 > DTI < / RTI > condition. delete delete A storage medium storing a method of protecting a DPF in a DTI condition according to any one of claims 1 to 4, 6 to 7. A storage medium (100) according to claim 10;
A measurement unit 200 for measuring a temperature change amount per unit time at the rear end of the DPF; And
A controller 400 for controlling the RPM of the engine 300 according to a method of protecting the DPF in the DTI condition stored in the storage medium 100 using the temperature variation measured by the measuring unit 200;
Wherein the DPF is in the DTI condition.

Images