JP4469207B2 - How to eliminate filter clogging - Google Patents

Description

The present invention relates to filter clogging resolving how extinguish solutions clogging of black smoke removing filter.

  As shown in FIG. 6, a black smoke purification device 3 for removing black smoke in exhaust gas discharged from an engine 2 that drives a hydraulic pump 1 of a hydraulic circuit is mounted on a hydraulic excavator for a tunnel or the like. Yes.

This black smoke purification device 3 is provided with a black smoke removal filter 5 in which an oxidation catalyst is supported on a porous ceramic honeycomb structure in a filter casing 4, and when the engine 2 is operated at a high load, The oxidation catalyst is activated by the temperature of the exhaust gas that has become, and the soot collected in the black smoke removal filter 5 burns to regenerate (see, for example, Patent Document 1).
JP 2002-309923 A (page 3, FIG. 3)

  The black smoke purification device 3 does not burn soot trapped by the black smoke removal filter 5 because the exhaust gas temperature does not rise sufficiently when there are many light loads such as light work and idling.

  For this reason, the black smoke removal filter 5 is clogged with soot, and the output of the engine 2 may be reduced, or in an extreme case, the engine exhaust pressure may be increased, the engine may not start, or the turbocharger may be broken.

The present invention may also be such a made in view of the problems, aims to provide a filter plugging resolution methods to eliminate clogging of black smoke removing filter playable by the exhaust gas temperature discharged from the engine It is.

請 Motomeko 1 invention described detects the inlet side of the engine exhaust pressure of black smoke removing filter for removing black smoke in exhaust gas discharged from an engine for driving a pump for supplying hydraulic fluid to a working actuator, If the engine exhaust pressure reaches the specified pressure for a specified time, the pump output is lowered at least.When the pump output decreases, the pump output is restored to the original pump output state for a certain period of time by the return operation. This is a filter clogging elimination method that restores the engine and operates the engine at a high load for a certain period of time. The operator has stopped the operation actuator due to a decrease in pump output, etc., and the filter has reached a clogged state. Therefore, at that time, the pump output is returned to the original state for a certain period of time by the return operation, and the pump output is restored during the return state of the pump output. The emission operating at high load, by burning the soot trapped in the filter by the hot exhaust gas temperature discharged from the engine, eliminate the clogging due to soot black smoke removing filter, to regenerate.

According to a second aspect of the invention, the resolution method blockage filter eyes according to claim 1, the engine high load operation of the predetermined time, if the engine exhaust pressure is equal to or less than the predetermined value within a predetermined time, thereafter also pump output If the engine exhaust pressure does not fall below the specified value within a certain period of time, this is a filter clogging elimination method that lowers the pump output at least.If a decrease in the engine exhaust pressure is confirmed during high engine load operation, It is possible to continue the operation as it is. On the other hand, only when no decrease in engine exhaust pressure is confirmed, it is possible to prompt the replacement of the filter by reducing the pump output or the like, so that the working efficiency is improved.

According to the invention 請 Motomeko 1 wherein the operator, a working actuator due to a reduction in the pump output operation stop, etc., since it can be seen that the filter has reached a clogging state, then the constant by return operation To return the pump output to the original state for a period of time and to operate the engine at a high load during the return state of the pump output and burn the soot collected in the filter by the high temperature exhaust gas temperature discharged from the engine Thus, clogging of the black smoke removal filter due to soot can be eliminated and regenerated.

According to the second aspect of the present invention, when a decrease in the engine exhaust pressure is confirmed by the engine high load operation, the operation can be continued as it is, but only when a decrease in the engine exhaust pressure is not confirmed. Since filter replacement can be promoted by lowering the pump output or the like, work efficiency can be improved.

  Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIGS.

  As shown in FIG. 1, a hydraulic excavator 11 for work in a tunnel as a work machine is shown. This hydraulic excavator 11 is provided with a lower traveling body 12 so that an upper swing body 13 can be swung. In addition, a cab 14, a power unit 15, and a work unit 16 are mounted.

  The lower traveling body 12 is provided with a traveling motor 21 as a working actuator, the upper revolving body 13 is provided with a turning motor 22 as a working actuator, and the working device 16 has a boom cylinder 23 as a working actuator, An arm cylinder 24 and a bucket cylinder 25 are provided.

  These traveling motor 21, turning motor 22, boom cylinder 23, arm cylinder 24 and bucket cylinder 25 are driven by hydraulic oil as working fluid discharged from a main pump 32 as a pump driven by an engine 31 of the power unit 15. It is a hydraulic actuator that is actuated.

  The operation of these hydraulic actuators is controlled by a control valve 33 provided in a pipe between the main pump 32 and each hydraulic actuator. The control valve 33 incorporates a plurality of spools corresponding to each hydraulic actuator, and these spools are respectively operated by pilot pressure oil supplied from an operating device 34 such as an operating lever installed in the cab 14. Is done.

  An engine 31 that drives a main pump 32 that supplies hydraulic oil to a hydraulic actuator is equipped with a black smoke purification device 35 for removing black smoke in exhaust gas discharged from the engine 31.

  This black smoke purification device 35 is provided with a black smoke removal filter 37 in which an oxidation catalyst is supported on a porous ceramic honeycomb structure in a filter casing 36. When the engine 31 is operated at a high load, this engine The oxidation catalyst is activated by the high exhaust gas temperature discharged from 31 and the soot collected by the black smoke removal filter 37 burns, so that the clogging caused by this soot is eliminated and the black smoke removal filter 37 is regenerated. Have the ability to

  The main pump 32 is a variable displacement pump that can control the displacement variable means 42 such as a swash plate by a regulator 41. The regulator 41 is an actuator that can be controlled by a controller 43 via an output setting valve 44 such as an electromagnetic proportional valve. is there.

  An output signal line of an engine speed sensor 45 that detects the rotational speed (engine speed) of the engine 31 is connected to the input side of the controller 43, and also to the inlet side of the black smoke removal filter 37 in the black smoke purification device 35. The output signal line of the provided pressure detector 46 is connected, the output signal line of the pressure detector 47 provided in the discharge pipe of the main pump 32 is connected, and the reset switch 48 is further connected.

  On the other hand, the output side of the controller 43 is connected to the electromagnetic coil portion of the output setting valve 44 and is connected to an alarm 49 as a warning means. As the alarm 49, a buzzer, a monitor or the like may be used.

  Next, a control method by the controller 43 shown in FIG. 1 will be described with reference to the flowcharts shown in FIGS. The circled numbers in the figure are step numbers.

  As shown in FIG. 2, the signals of the pressure detector 46 and the reset switch 48 are read (step 1), and in the exhaust gas discharged from the engine 31 that drives the main pump 32 that supplies the hydraulic oil to the hydraulic actuators 21 to 25. The pressure sensor 46 detects the engine exhaust pressure on the inlet side of the black smoke removal filter 37 that removes the black smoke. The engine exhaust pressure signal is filtered (step 2) to determine the mode (step 3).

  In this mode determination, when the engine exhaust pressure detected by the pressure detector 46 is equal to or less than a specified value, it is determined as the working mode (step 4), and the engine exhaust pressure detected by the pressure detector 46 is the specified value. When the above is true and the reset switch 48 is in the OFF state, the clogging mode is determined (step 5), the engine exhaust pressure detected by the pressure detector 46 is equal to or greater than a specified value, and the reset switch 48 When is on, the playback mode is determined (step 6).

  As shown in FIG. 3, in the work mode, the pump output is set to a work set value (step 7). It is determined whether or not the engine exhaust pressure of the black smoke purification device 35 has reached a specified value and the state has continued for a specified time (step 8), and the engine exhaust pressure of the black smoke purification device 35 has reached the specified pressure and the state Is continued for the specified time (step 8 YES), the filter is regarded as clogged, and the clogging mode (step 5) is set.

  As shown in FIG. 4, in this clogging mode, it is determined whether or not the reset switch 48 is on (step 9). If the reset switch 48 is not on, the output setting valve 44 uses the regulator 41 to output the pump. Is greatly reduced (step 10), and a clogging alarm is output to the alarm device 49 (step 11).

  On the other hand, if there is a return operation to turn on the reset switch 48 in this clogged state (YES in step 9), the playback mode is set and the timer is reset (step 12).

  As shown in FIG. 5, in this regeneration mode, the regulator 41 is controlled via the output setting valve 44 to return the pump output to the original pump output state for a certain period of time (step 13). A clogging alarm is output from the device 49 (step 14).

  Further, the engine 31 is set to a high idle state for a certain period of time, and a relief operation is performed to continue operating the operating device 34 in the same direction even after the hydraulic actuators 23 to 25 are operated to the dead point. It is determined whether or not the vehicle has actually been operated at a high load. That is, the engine speed detected by the engine speed sensor 45 is in a high idle state, and the discharge pressure of the main pump 32 detected by the pressure detector 47 is a relief valve (not shown) provided in the discharge line. It is determined whether or not the relief pressure set in (1) has been reached (step 15).

  If NO is determined in step 15, the timer is counted up (step 16), it is determined whether the timer has reached a specified value (step 17), and the timer is When the specified value is reached, the process proceeds to the clogging mode (step 5).

  On the other hand, if YES is determined in step 15, the engine is operated at a high load in a relief state in which the engine speed is in a high idle state and the pump discharge pressure reaches the relief pressure, and black smoke is generated due to a high exhaust gas temperature. (煤) may have burned, so it is determined whether the engine exhaust pressure has fallen below the specified value (step 18), and the soot burns due to the high exhaust gas temperature during a certain period of high engine load. When the engine exhaust pressure falls below the specified value, it is considered that the black smoke removal filter 37 has been regenerated, the operation mode is set, the pump output is returned to the original work setting value, and the timer is reset ( Step 19).

  On the other hand, if the engine exhaust pressure does not fall below the specified value within a certain time in step 18, it is considered that the engine is clogged, and the pump output is greatly reduced by clogging mode (step 5). Output clogging alarm.

  Thus, if the engine exhaust pressure reaches the specified pressure for a specified time, the black smoke removal filter 37 is clogged, so an alarm is output from the alarm 49 and the pump output is reduced. By stopping or lowering the hydraulic actuators 21 to 25 that operate with this pump output so that unreasonable work cannot be continued, failure of the engine 31 and the black smoke removal filter 37 can be prevented. In addition, it is possible to prompt the operator to take measures against clogging such as replacement of the black smoke removal filter 37 and regeneration operation for operating the engine 31 with a high load.

  Furthermore, the operator knows that the black smoke removal filter 37 has reached the clogged state due to the suspension of the hydraulic actuators 21 to 25 due to the decrease in the pump output, etc. In that case, the reset operation is performed by pressing the reset switch 48. Thus, the pump output is returned to the original state for a certain time, the engine 31 is operated at a high load during the return state of the pump output, and the black smoke removal filter 37 is driven by the high temperature exhaust gas temperature discharged from the engine 31. By burning the soot collected in this, clogging of the black smoke removal filter 37 due to soot can be eliminated, and the black smoke purification device 35 can be regenerated.

  In addition, if a decrease in engine exhaust pressure is confirmed due to high-load operation of engine 31, the operation can be continued as it is, while the pump output is decreased only when a decrease in engine exhaust pressure is not confirmed. Thus, the filter replacement can be promoted, so that the work efficiency can be improved.

  The present invention can be applied not only to hydraulic excavators but also to other construction machines and work machines.

Is a block diagram illustrating one embodiment of a system configuration according to the filter clogging resolution method of the present invention. It is a calculation flowchart of the mode determination which concerns on a method same as the above. It is a calculation flowchart of the work mode which concerns on a method same as the above. It is a calculation flowchart of clogging mode which concerns on a method same as the above. It is a calculation flowchart of the reproduction | regeneration mode based on a method same as the above. It is a side view of the engine by which the black smoke purification apparatus is mounted.

21 ~ 25 Hydraulic actuator as working actuator
31 engine
32 Main pump as pump
37 Black smoke removal filter

Claims (2)

Detecting the engine exhaust pressure on the inlet side of the black smoke removal filter that removes black smoke in the exhaust gas discharged from the engine that drives the pump that supplies the working fluid to the working actuator;
If the engine exhaust pressure reaches the specified pressure for a specified time, at least reduce the pump output,
When this pump output drops, the return operation returns the pump output to the original pump output state for a certain period of time,
A filter clogging elimination method characterized by operating the engine at a high load for a certain period of time. If the engine exhaust pressure drops below the specified value within a certain period of time due to high engine load operation for a certain period of time, the pump output will be restored after that,
If the engine exhaust pressure does not become less than the prescribed value within a predetermined period of time, filter plugging resolution method according to claim 1, wherein the lowering at least the pump output.

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