JP2010059620A - Control unit of construction machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To complete a filter regenerating action, and to surely prevent the abrupt actuation of an actuator. <P>SOLUTION: When a regeneration starting switch 15 is operated and it is determined that the regeneration of a filter is required, a high idle speed is outputted to an engine control section 10 from a controller 12 according to a signal from an accumulation amount sensor 16, a pump discharge rate maximum command is outputted to a pump regulator 11, a closing command is outputted to an unloading valve 9, and pilot pressure shutoff commands are outputted to pilot pressure shutoff valves 7 and 7. Thus, even if remote-controlled valves 5 and 5 are operated during filter regeneration control, a control valve 3 does not operate, the filter regenerating action is completed, and the actuation of the hydraulic actuator 4 is stopped. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for incinerating harmful substances accumulated in an exhaust gas filter under a certain condition to regenerate the filter in a construction machine such as a hydraulic excavator.

  Conventionally, exhaust gas discharged from a diesel engine is introduced into an exhaust gas filter (DPF: Diesel Particulate Filter) to remove harmful substances, especially PM (Particulate Matter: Particulate matter; explained in this example below) such as soot An exhaust gas purification device for purification is known (see Patent Document 1).

  In this type of exhaust gas purification device, in order to keep the purification function of the exhaust gas filter constant, filter regeneration (self-regeneration) that burns and removes PM deposited on the exhaust gas filter when the amount of PM deposition exceeds a certain level Also called).

This filter regeneration is performed, for example, by simultaneously increasing the discharge amount and discharge pressure of the hydraulic pump and increasing the engine output to raise the exhaust gas temperature (usually raising the exhaust gas at 150 to 250 ° C. to 350 to 600 ° C.). Is called.
Japanese Patent No. 3073380

  As described above, when the filter is regenerated, the pump discharge amount and the discharge pressure are increased in order to raise the exhaust gas temperature. Therefore, if the control valve is erroneously operated during this filter regeneration, the actuator suddenly operates.

  In the known technique described in Patent Document 1, as a countermeasure against this point, a configuration is adopted in which the reproduction control is canceled when the operating means is operated during reproduction.

  However, if this is done, the filter regeneration function cannot be completed, and the exhaust gas purification function is degraded.

  Further, even if the filter regeneration control is canceled, the circuit pressure does not drop suddenly, so the effect of preventing the sudden operation of the actuator is low.

  Therefore, the present invention provides a control device for a construction machine that can complete the filter regeneration operation and reliably prevent the sudden operation of the actuator.

  The invention of claim 1 includes an engine, a hydraulic pump as a hydraulic source of the hydraulic actuator, a control valve for controlling the operation of the hydraulic actuator, an operating means for operating the control valve, and an exhaust gas from the engine. An exhaust gas filter that removes harmful substances, an operation detection unit that detects whether or not the operation unit is operated, an operation stop unit that disables operation of the control valve by the operation unit, and a control unit. The control means incinerates harmful substances accumulated in the exhaust gas filter by increasing the engine output and raising the exhaust gas temperature on the condition that the operation means is not operated based on the signal from the operation detection means. The filter regeneration control is performed and an operation stop command is issued to the operation stop means. Those were.

  According to a second aspect of the present invention, in the configuration of the first aspect, an unload passage blocking means for closing the passage is provided in the unload passage for unloading the discharge oil of the hydraulic pump, and the control means rotates the engine when the filter regeneration starts. The number is increased, the discharge amount of the hydraulic pump is maximized, and the unload passage is closed by the unload passage blocking means.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, a regeneration start switch for starting filter regeneration based on an operator's intention and data for determining whether or not regeneration of the exhaust gas filter is necessary are detected. A reproduction data detection means, and the control means is configured to perform filter reproduction control when it is determined that filter reproduction is necessary based on a signal from the reproduction data detection means when the reproduction start switch is operated. It has been done.

  According to a fourth aspect of the present invention, in the configuration of any one of the first to third aspects, the hydraulic pilot type control valve is configured to be operated by a pilot pressure from a remote control valve as an operation means. A pilot pressure shut-off valve as an operation stop means for shutting off the pilot pressure based on an operation stop command from the control means is provided on a pilot line connecting the control valve.

  According to a fifth aspect of the present invention, in the configuration according to any one of the first to fourth aspects, the control means starts the regeneration control on the condition that the operating means has not been operated and that this state has passed for a certain period of time. It is comprised so that it may make it.

  According to the present invention, during filter regeneration, an interlock is applied that disables the control valve regardless of the operation of the operation means, so that the filter regeneration operation can be completed.

  In addition, during the filter regeneration, the control valve is not moved by the interlock function, and pressure oil is not sent to the actuator, so that the sudden operation of the actuator can be reliably prevented.

  In particular, as in the case of the invention of claim 2, when the engine speed is increased at the same time as the regeneration of the filter and the discharge amount and discharge pressure of the hydraulic pump are maximized, the degree of sudden operation of the actuator is large, so this is prevented. By doing so, the effect of ensuring safety is high.

  According to the invention of claim 3, since the filter regeneration is started on the condition that the filter regeneration is necessary and the operator operates the regeneration start switch with the intention of the filter regeneration, the filter regeneration action is wasted at an accurate timing. Done without.

  According to the invention of claim 4, since the control valve is made inoperable by shutting off the pilot pressure, for example, the interlock effect is more reliable as compared with the case where a mechanical lock is applied to the remote control valve.

  According to the invention of claim 5, since the filter regeneration control is started when the non-operation of the operation means continues for a predetermined time or more (when the operator's intention to start filter regeneration is clear), wasteful regeneration control (claim 3) In the case of the present invention, it is possible to avoid the start of the regeneration control based on the erroneous operation of the regeneration start switch that is unrelated to the operator's intention.

  In the construction machine according to the embodiment, as shown in FIG. 1, a variable displacement hydraulic pump 2 is driven by an engine 1, and oil discharged from the hydraulic pump 2 passes through a control valve 3 to a plurality of hydraulic actuators (here, one Supplied as 4).

  The control valve 3 is configured as a hydraulic pilot switching valve that is operated by a pilot pressure from remote control valves 5 and 5 as operation means to control the direction and flow rate of pressure oil supply to the hydraulic actuator 4.

  A pilot pressure shut-off valve as an operation stop means for shutting off the pilot pressure sent from the remote control valves 5 and 5 to the pilot lines 6 and 6 connecting the pilot ports on both sides of the control valve 3 and the remote control valves 5 and 5. (Electromagnetic on-off valves) 7 and 7 are provided.

  On the other hand, an unload valve 9 as an unload passage blocking means for closing the passage 8 is provided in the unload passage 8 for unloading pump discharge oil from the control valve 3 to the tank T.

  The control means includes an engine control unit 10 that controls the rotational speed of the engine 1, a pump regulator 11 that controls the discharge amount (tilt) of the hydraulic pump 2, and a controller 12, and from the controller 12 during filter regeneration, Various commands for regeneration control, that is, a high idle speed command for the engine control unit 10, a maximum discharge amount command for the pump regulator 6, a pilot pressure cutoff command for the pilot pressure cutoff valves 7 and 7, and a close command for the unload valve 9 Are each output.

  On the other hand, an exhaust gas filter 14 is provided in the exhaust passage 13 for releasing the exhaust gas from the engine 1 to the outside, and PM in the exhaust gas is removed by the exhaust gas filter 14.

  Further, a regeneration start switch 15 for starting filter regeneration control based on the operator's intention is provided, and regeneration data detection means for detecting the PM accumulation amount of the exhaust gas filter 14 as a sensor for obtaining information for filter regeneration. Are stored, and pilot pressure sensors 17 and 17 are provided as operation detecting means for detecting whether or not the remote control valves 5 and 5 are operated by the pilot pressure of the pilot lines 6 and 6, respectively.

  Based on these signals, the controller 12 performs filter regeneration control in a timely manner. The operation of this point will be described with reference to the flowchart of FIG.

  In step S1, it is determined whether or not the regeneration start switch 15 has been operated. If YES, it is determined in step S2 whether or not filter regeneration is necessary based on the signal from the accumulation amount sensor 16.

  If it is determined that filter regeneration is necessary, it is determined in step S3 whether or not the no-operation state has elapsed for a certain period of time. If YES, it is determined that the operator is willing to perform filter regeneration and filter regeneration control is performed in step S4. Is started.

  That is, a pilot pressure cutoff command for the pilot pressure cutoff valve 7 (step S6), a high idle speed command for the engine control unit 10 (step S7), a pump maximum discharge amount command for the pump regulator 11 (step S8), an unload valve 9 A close command (step S9) is output for each.

  By these processes, the engine output increases, the exhaust gas temperature rises to a temperature suitable for filter regeneration, and the filter regeneration action is performed.

  In step S10, it is determined whether or not the filter regeneration operation has been completed based on the signal from the accumulation amount sensor 16, and when completed, the filter regeneration control is terminated in step S11, the normal control is resumed, and the process returns to step S1.

  According to this control device, even if the remote control valves 5, 5 are operated during filter regeneration, the pilot pressure is shut off by the pilot pressure shut-off valves 7, 7, and the control valve 3 becomes inoperable (becomes an interlock state). Therefore, the filter regeneration operation is surely completed.

  In addition, during the filter regeneration, the control valve 3 does not move by the interlock function, and pressure oil is not sent to the hydraulic actuator 4, so that sudden operation of the hydraulic actuator 4 can be reliably prevented.

  In particular, as in this embodiment, when the engine speed is increased at the start of filter regeneration and the discharge amount and discharge pressure of the hydraulic pump 2 are maximized, the degree of sudden operation of the hydraulic actuator 4 is large. The effect of ensuring safety is high by being able to prevent.

  Further, since the filter regeneration is started on the condition that the filter regeneration is necessary and the operator has an intention to perform the filter regeneration (the regeneration start switch 15 is operated), the filter regeneration operation is wasted at an accurate timing. Done without.

  Furthermore, since the control valve 3 is made inoperable by shutting off the pilot pressure, the interlock effect is more reliable as compared with a case where a mechanical lock is applied to the remote control valve, for example.

  On the other hand, when the non-operation of the remote control valve 5 continues for a certain time or longer (when the operator has a clear intention to perform the regenerating operation), the regenerating operation is started, and therefore, a regenerative operation that is useless (for example, regeneration unrelated to the operator's intention). It is possible to avoid the start of a regeneration action based on an erroneous operation of the start switch 15.

Other Embodiments (1) As the operation means, operation detection means, and operation stop means, those other than the remote control valve 5, the pilot pressure sensor 17, and the pilot pressure cutoff valve 7 exemplified in the above embodiment can be used.

  For example, in the case of using a direct-acting type switching valve (a system in which the spool is directly operated by lever operation) as the control valve 3, the lever serves as the operating means, and the operation detecting means detects the movement of the lever (such as a limit switch). ) May be used.

  Further, as the operation stop means, a valve that shuts off the primary pressure of the remote control valve 5 in the above embodiment may be used, or a mechanical lock that prevents the remote control valve 5 from moving may be used.

  (2) As part of the filter regeneration control, a fuel injection control, that is, a method of heating the exhaust gas by post-injecting fuel on the engine side may be used.

  (3) In the above embodiment, the filter regeneration control is started based on the operation of the regeneration start switch 15 by the operator. However, when the filter regeneration is necessary, the filter regeneration control is automatically started. You may take the structure to do. In this case, it is desirable to display to the operator that the filter regeneration control is being performed.

It is a block diagram which shows the whole structure of the control apparatus concerning embodiment of this invention. It is a flowchart for demonstrating the effect | action of the apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Hydraulic pump 3 Control valve 4 Hydraulic actuator 5 Remote control valve as operation means 6 Pilot line 7 Pilot pressure cutoff valve as operation stop means 8 Unload passage 9 Unload valve as unload passage cutoff means 10 Control means Engine controller 11 constituting the structure 11 Pump regulator constituting the control means 12 Controller constituting the control means 14 Exhaust gas filter 15 Reproduction start switch 16 Accumulated amount sensor as reproduction data detection means 17 Pilot pressure sensor as operation detection means

Claims (5)

  An engine, a hydraulic pump as a hydraulic source of the hydraulic actuator, a control valve for controlling the operation of the hydraulic actuator, an operating means for operating the control valve, and an exhaust gas filter for removing harmful substances in the exhaust gas emitted from the engine An operation detecting means for detecting whether or not the operating means is operated, an operation stopping means for disabling the operation of the control valve by the operating means, and a control means. Filter regeneration control for incinerating harmful substances accumulated in the exhaust gas filter by increasing the engine output and increasing the exhaust gas temperature on the condition that the operation means is not operated based on the signal from the operation detection means And an operation stop command to the operation stop means. Construction machine control device.   The unload passage that unloads the hydraulic pump discharge oil is provided with an unload passage blocking means that closes the passage, and the control means increases the engine speed when the filter regeneration starts and maximizes the discharge amount of the hydraulic pump. The construction machine control device according to claim 1, wherein the unload passage is closed by the unload passage blocking means.   A regeneration start switch for starting filter regeneration based on the operator's intention and a regeneration data detecting means for detecting data for determining whether regeneration of the exhaust gas filter is necessary are provided, and the control means is configured to start the regeneration. 3. The construction machine according to claim 1, wherein filter regeneration control is performed when it is determined that filter regeneration is necessary based on a signal from the regeneration data detecting means when the switch is operated. Control device.   A hydraulic pilot type control valve is configured to be operated by a pilot pressure from a remote control valve as an operation means, and a pilot line connecting the remote control valve and the control valve is operated based on an operation stop command from the control means. The construction machine control device according to any one of claims 1 to 3, wherein a pilot pressure shut-off valve is provided as an operation stop means for shutting off the pilot pressure.   5. The control means according to claim 1, wherein the control means is configured to start the regeneration control on condition that the operation means has not been operated and the state has passed for a certain period of time. The control device for a construction machine according to item 1.

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