Patent Application
20120330531
The present invention relates to an engine device which is mounted on a working machine, for example, an engine power generator, a farm working machine, and a construction machine.
In recent years, in conjunction with an application of a high level exhaust gas regulation with regard to a diesel engine (hereinafter, refer simply to as an engine), it is going to be desired to mount an exhaust gas purifying device which purifies an air contaminant in the exhaust gas onto an engine power generator, a farm working machine, a construction machine or the like on which the engine is mounted. As the exhaust gas purifying device, a diesel particulate filter (hereinafter, refer to as DPF) has been known (refer to Patent Documents 1 and 2). The DPF is provided for collecting a particulate matter (hereinafter, refer to as PM) in the exhaust gas. In this case, if the PM collected by the DPF goes beyond a prescribed amount, a distribution resistance within the DPF is increased so as to cause a reduction of an engine output. Accordingly, it is frequently carried out to remove the PM which is piled up in the DPF by a temperature rise of the exhaust gas and recover a PM collecting capacity of the DPF (regenerate the DPF).
In this case, the engine is mounted on various working machines, for example, the engine power generator, the compressor, the farm working machine and the construction machine. Accordingly, in the engine with the DPF, a specification required for regenerating the DPF (a necessary engine auxiliary machine or the like) is various in correspondence to a kind of the working machine which is a subject to be mounted, and a control program for regenerating the DPF which is executed by an ECU is necessary in correspondence to the working machine. Accordingly, even if the type of the engine and the specification as a hardware of the ECU are the same, the control program stored in the ECU is different in correspondence to the working machine. Accordingly, there has been such a problem that a general purpose property of the ECU is low. Further, it is necessary for a manufacturer not only to control the various ECU in correspondence to the working machines at a time of manufacturing the engine, but also store the ECU in correspondence to the working machine as a parts inventory for a breakaway correspondence and a maintenance, after shipping the engine. Therefore, a control and store cost increases.
Accordingly, a technical object of the present invention is to provide an engine device to which an improvement is applied after making a study of the actual condition mentioned above.
In accordance with a first aspect of the present invention, there is provided an engine device including:
an exhaust gas purifying device which is arranged in an exhaust route of an engine; and
an ECU which controls a drive of the engine,
wherein the engine device is provided with a variable memory means which stores a general-purpose regeneration program selectively executing any of a plurality of regeneration modes with respect to the exhaust gas purifying device, and a flag table corresponding to an optional regeneration mode, and is rewritable, and the ECU executes the general-purpose regeneration program in accordance with the regeneration mode which is selected on the basis of the flag table.
In accordance with a second aspect of the present invention, in the engine device described in the first aspect, a fixed memory means which fixedly stores the flag table is provided, and the flag table stored in the fixed memory means is written in the variable memory means at a first accessing time of the fixed memory means and the variable memory means.
In accordance with a third aspect of the present invention, in the engine device described in the first aspect, a plurality of regeneration modes are provided with at least a self regeneration mode which drives the engine under a condition that the exhaust gas purifying device is regenerable, an automatic auxiliary regeneration mode which automatically raises a temperature of the exhaust gas in the case that a clogged degree of the exhaust gas purifying device goes beyond a prescribed level, and a manual auxiliary regeneration mode which allows the regeneration of the exhaust gas purifying device on the basis of a turn-on operation of a manual operating means.
In accordance with a fourth aspect of the present invention, in the engine device described in any one of the first to third aspects, necessity of a trouble diagnosis of an engine auxiliary machine which is relevant to the regeneration of the exhaust gas purifying device is determined in correspondence to the flag table, at a time of executing the general-purpose regeneration program.
In accordance with the first aspect of the present invention, in the engine device including: the exhaust gas purifying device which is arranged in the exhaust route of the engine, and the ECU which controls the drive of the engine, the engine device is provided with the variable memory means which stores the general-purpose regeneration program selectively executing any of a plurality of regeneration modes with respect to the exhaust gas purifying device, and the flag table corresponding to the optional regeneration mode, and is rewritable, and the ECU executes the general-purpose regeneration program in accordance with the regeneration mode which is selected on the basis of the flag table. Accordingly, it is possible to correspond to the different regeneration modes per kind of the working machines, only by changing the flag table in one kind of the general-purpose regeneration program. In accordance with this, it is possible to achieve such an effect that a common use (a common specification) of the ECU can be achieved with respect to the various working machines. In other words, it is possible to achieve an effect that an advantage of an improvement of the general purpose property of the ECU and an advantage of ensuring adequacy with respect to each of the regeneration modes of the ECU are compatible.
Further, it is not necessary to develop the program for regenerating the exhaust gas purifying device per kind of the various working machine, and there is an advantage that it contributes to a cost suppression. Further, since the general-purpose regeneration program can be easily switched to one which corresponds to the kind of the working machine only by changing the flag table without any special knowledge of a programming, it becomes easy to provide an engine device which meets a customer's (an engine buying manufacture's) demand.
In accordance with the second aspect of the present invention, in the engine device described in the first aspect, the fixed memory means which fixedly stores the flag table is provided, and the flag table stored in the fixed memory means is written in the variable memory means at the first accessing time of the fixed memory means and the variable memory means. Accordingly, it is possible to easily execute the DPF regeneration control in accordance with a different regeneration mode from an initial setting, by rewriting the flag table which is stored in the variable memory means later. Therefore, in the case that it is intended to change the regeneration mode, it is not necessary to delete the flag table each time, for example, by changing the fixed memory means, or to rewrite the general-purpose regeneration program, and there is obtained such an effect that it is easy to cope with the systems of the various working machines. For example, for the customer, it is easy to modify a setting to a setting which is suitable for its own specification in spite of the engine which is bought externally.
In accordance with the third aspect of the present invention, in the engine device described in the first or second aspect, a plurality of regeneration modes are provided with at least the self regeneration mode which drives the engine under the condition that the exhaust gas purifying device is regenerable, the automatic auxiliary regeneration mode which automatically raises the temperature of the exhaust gas in the case that the clogged degree of the exhaust gas purifying device goes beyond the prescribed level, and the manual auxiliary regeneration mode which allows the regeneration of the exhaust gas purifying device on the basis of the turn-on operation of the manual operating means. Accordingly, it is possible to cope with a plurality of regeneration modes which are suitable for the various types of working machines, by the system of the one kind of engine device. Therefore, there can be obtained such an effect that it is possible to further improve a customer satisfaction.
In accordance with the fourth aspect of the present invention, in the engine device described in any one of the first to third aspects, necessity of the trouble diagnosis of the engine auxiliary machine which is relevant to the regeneration of the exhaust gas purifying device is determined in correspondence to the flag table, at a time of executing the general-purpose regeneration program. Accordingly, even if the engine auxiliary machine is provided or not on the basis of the difference of the regeneration mode, it is possible to execute the trouble diagnosis of the engine auxiliary machine if necessary, only by one kind of the general-purpose regeneration program, and it is possible to omit the trouble diagnosis of the engine auxiliary machine if not necessary. In other words, there can be obtained such an effect that the execution and the omit of the trouble diagnosis can be easily switched in correspondence to whether or not the engine auxiliary machine is provided, without any detail-oriented setting and operation.
A description will be given below of an embodiment which embodies the present invention on the basis of the accompanying drawings.
(1) Engine and Peripheral Structure Thereof
First of all, a description will be given of an engine and a peripheral structure thereof with reference to
As shown in
In the structure mentioned above, the fuel in the fuel tank 118 is pressure fed to the common rail 120 by the fuel supply pump 116, and the fuel having a high pressure is stored in the common rail 120. Since each of the fuel injection valves 119 is controlled so as to be opened and closed, the fuel having the high pressure within the common rail 120 is injected from each of the injectors 115 to each of the cylinders of the engine 70. In other words, an injection pressure, an injecting timing, and an injection period (an injection amount) of the fuel which is supplied from each of the injectors 115 are controlled at a high precision, by electronically controlling each of the fuel injection valves 119. Accordingly, it is possible to reduce a nitrogen oxide (NOx) from the engine 70, and to reduce a noise vibration of the engine 70.
In this case, as shown in
To an exhaust pipe 77 which is connected to an exhaust downstream side of the exhaust manifold 71, there are connected an exhaust throttle device 82 for adjusting an exhaust pressure of the engine 70, and a diesel particulate filter 50 (hereinafter, refer to as DPF) which is one example of an exhaust gas purifying device. The exhaust gas which is discharged from each of the cylinders to the exhaust manifold 71 is purified through the exhaust pipe 77, the exhaust throttle device 82, and the DPF 50, and is thereafter discharged to an external portion.
The DPF 50 is provided for collecting a particulate matter (hereinafter, refer to as PM) in the exhaust gas. The DPF 50 in accordance with the embodiment is structured such that a diesel oxidizing catalyst 53, for example, a platinum or the like, and a soot filter 54 are lined up in series so as to be accommodated in an approximately tubular filter case 52 which is within a casing made of a heat resisting metal material. In the embodiment, the diesel oxidizing catalyst 53 is arranged in an exhaust upstream side within the filter case 52, and the soot filter 54 is arranged in an exhaust downstream side. The soot filter is formed as a honeycomb structure having a lot of cells which are zoned by a porous (filterable) partition wall.
One side portion of the casing 51 is provided with an exhaust introduction port 55 which is communicated with the exhaust downstream side of the exhaust throttle device 82 in the exhaust pipe 76. One end portion of the casing 51 is clogged by a first bottom plate 56, and one end portion facing to the first bottom plate 56 in the filter case 52 is clogged by a second bottom plate 57. A heat insulating material 58 such as a glass wool is filled in an annular gap between the casing 51 and the filter case 52, and a gap between both the bottom plates 56 and 57 in such a manner as to surround a periphery of the diesel oxidizing catalyst 53 and the soot filter 54. The other end portion of the casing 51 is clogged by two lid plates 59 and 60, and an approximately tubular exhaust discharge port 61 passes through both the lid plates 59 and 60. Further, a portion between both the lid plates 59 and 60 comes to a resonance chamber 63 which is communicated within the filter case 52 via a plurality of communication pipes 62.
An exhaust gas introduction pipe 65 is inserted to an exhaust introduction port 55 which is formed in one side portion of the casing 51. A leading end of the exhaust gas introduction pipe 65 cuts across the casing 51 and protrudes to a side face opposite to the exhaust introduction port 55. A plurality of communication holes 66 which are open toward the filter case 52 are formed in an outer peripheral surface of the exhaust gas introduction pipe 65. A portion protruding to the side face opposite to the exhaust introduction port 55 in the exhaust gas introduction pipe 65 is clogged by a lid body 67 which is detachably attached by screw thereto.
The DPF 50 is provided with a differential pressure sensor 68 which detects a clogged state of the soot filter 54 as one example of the detecting means. The differential pressure sensor 68 in accordance with the embodiment is structured such as to detect a pressure difference (a differential pressure) between upstream and downstream sides with respect to the soot filter 54 within the DPF 50. In this case, an upstream side exhaust pressure sensor 68a which constructs the differential pressure sensor 68 is installed to the lid body 67 of the exhaust gas introduction pipe 65, and a downstream side exhaust pressure sensor 68b is installed between the soot filter 54 and the resonance chamber 63. It has been well known that a fixed rule exists between the pressure difference between the upstream and downstream sides of the DPF 50 and a PM stacking amount within the DPF 50. In the embodiment, a regeneration control (a DPF regeneration control) of the soot filter 54 is executed by estimating the PM stacking amount within the DPF 50 from the pressure difference which is detected by the differential pressure sensor 68, and actuating the intake throttle device 81, the exhaust throttle device 82, and the common rail 120 on the basis of a result of estimation.
In this case, a structure detecting the clogged state of the soot filter 54 is not limited to the differential pressure sensor 68, but may be an exhaust pressure sensor which detects the pressure in the upstream side of the soot filter 54 within the DPF 50. In the case that the exhaust pressure sensor is employed, the clogged state of the soot filter 54 is determined by comparing a pressure (a reference pressure) in the upstream side of the soot filter 54 at a brand-new state in which the PM is not stacked in the soot filter 54, with the current pressure which is detected by the exhaust pressure sensor.
In the structure mentioned above, the exhaust gas from the engine 5 enters into the exhaust gas introduction pipe 65 via the exhaust introduction port 55, jets out into the filter case 52 from each of the communication holes 66 which are formed in the exhaust gas introduction pipe 65, is dispersed into a wide region within the filter case 52, and thereafter passes through the diesel oxidizing catalyst 53 and the soot filter 54 in this order so as to be purified. The PM in the exhaust gas can not pass through the porous partition wall between the cells in the soot filter 54 so as to be collected in this stage. Thereafter, the exhaust gas which passes through the diesel oxidizing catalyst 53 and the soot filter 54 is discharged out of the exhaust discharge port 61.
If an exhaust gas temperature goes beyond a regenerable temperature (for example, about 300° C.) at a time when the exhaust gas passes through the diesel oxidizing catalyst 53 and the soot filter 54, NO (nitrogen monoxide) in the exhaust gas is oxidized into an unstable NO2 (nitrogen dioxide) due to an action of the diesel oxidizing catalyst 53. Further, the PM collecting capacity of the soot filter 54 is recovered (the soot filter 54 (the DPF 50) is regenerated) by oxidizing and removing the PM which is stacked in the soot filter 54, by O (oxygen) which is discharged at a time when NO2 is returned to NO.
(2) Structure Relevant to Control of Engine
Next, a description will be given of a structure which is relevant to the control of the engine 70 with reference to
To an input side of the ECU 11, there are connected a rail pressure sensor 12 which detects at least a fuel pressure within the common rail 120, an electromagnetic clutch 13 which rotates or stops the fuel pump 116, an engine speed sensor 14 which detects a rotating speed of the engine 70 (a cam shaft position of the crank shaft 74), an injection setting device 15 which detects and sets a number of fuel injection of the injector 115 (a number during a fuel injection period of one stroke), a throttle position sensor 16 which detects an operating position of an accelerator operating device (an illustration of which is omitted) such as a throttle lever or an accelerator pedal, an intake temperature sensor 17 which detects an intake temperature in an intake route, an exhaust temperature sensor 18 which detects an exhaust gas temperature in an exhaust route, a cooling water temperature sensor 19 which detects a cooling water temperature of the engine 70, a fuel temperature sensor 20 which detects a fuel temperature within the common rail 120, a regeneration switch 21 serving as a manual operating means which selectively operates whether or not a manual auxiliary regeneration mode mentioned below is executed, and the differential pressure sensor 68 (the upstream side exhaust pressure sensor 68a and the downstream side exhaust pressure sensor 68b).
At least an electromagnetic solenoid of each of the fuel injection valves 119 for four cylinders is connected to the output side of the ECU 11. In other words, since the high pressure fuel which is stored in the common rail 120 is injected from the fuel injection valve 119 at plural times during one stroke, while controlling the fuel injection pressure, the injection timing, and the injection period, a generation of the nitrogen oxide (NOx) is suppressed, and a complete combustion in which a generation of a carbon dioxide or the like is reduced is executed, thereby improving a fuel consumption.
Further, to an output side of the ECU 11, there are connected the intake throttle device 81 for adjusting the intake pressure (the intake amount) of the engine 70, the exhaust throttle device 82 for adjusting the exhaust pressure of the engine 70, an ECU trouble lamp 22 which gives a warning and informs of the trouble of the ECU 11, an exhaust temperature warning lamp 23 which informs of an abnormally high temperature of the exhaust gas temperature, and a regeneration lamp 24 which is turned on in accordance with the execution of each of the regeneration modes mentioned below. The data relating to a blinking of each of the lamps 22 to 24 is previously stored in the EEPROM 33 of the ECU 11. In this case, as shown in
In the EEPROM 33 of the ECU 11, there is previously stored an output characteristic map M (refer to
The output characteristic map M is determined on the basis of an experiment or the like. In the characteristic map M shown in
The ECU 11 is basically structured such as to execute a fuel injection control of determining the torque T from the rotating speed N which is detected by the engine speed sensor 14 and the throttle position which is detected by the throttle position sensor 16, computing a target fuel injection amount by using the torque T and the output characteristic map M, and actuating the common rail system 117 on the basis of the result of computation. In this case, the fuel injection amount is adjusted by adjusting a valve opening period of each of the fuel injection valves 119 and changing the injection period to each of the injectors 115.
In the ROM 32 of the ECU 11, there is previously stored a flag table FT which corresponds to each of the regeneration modes relating to the regeneration control of the DPF 50. As shown in
The regeneration mode which is executed in the engine device includes, at least a self regeneration mode which drives the engine 70 under a condition that the DPF 50 is regenerable, an automatic auxiliary regeneration mode which automatically raises a temperature of the exhaust gas in the case that a clogged degree of the DPF 50 goes beyond a prescribed level, and a manual auxiliary regeneration mode which allows the regeneration of the DPF 50 on the basis of a turn-on operation of the regeneration switch 21. The self regeneration mode is mainly used in a working machine such as an engine power generator or the like which drives the engine 70 at approximately fixed rotating speed N and torque T. The automatic auxiliary regeneration mode is mainly used in a general working machine such as a combine harvester, a tractor or the like. The manual auxiliary regeneration mode is mainly used in a working machine such as a hydraulic shovel or the like which executes an accurate work on the basis of an engine sound. In this case, “under regenerable condition” in the self regeneration mode means a state in which the relationship between the rotating speed N and the torque T in the engine 70 is in the regenerable region (the upper region with respect to the boundary line BL) of the output characteristic map M, and the exhaust gas temperature of the engine 70 is high such that the PM oxidizing amount within the DPF 50 goes beyond the PM collecting amount.
Accordingly, in the case that the subject to be mounted to the engine is, for example, the engine power generator, the flag table FT1 for the self regeneration (refer to
One kind of flag table FT which is stored in the ROM 32 is written (copied) in the EEPROM 33 side at a first accessing time of the ROM 32 and the ERPROM 33, that is, at a time when the working machine is first turned on and the ROM 32 and the EEPROM 33 are electrically connected. The writing process is carried out at a time when the ECU 11 executes the main program MPM (refer to
(3) Aspect of Main Process
Next, as description will be given of one example of the main process of the DPF regeneration control by the ECU 11 with reference to a flow chart in
In accordance with the control mentioned above, since it is possible to easily execute the DPF regeneration control in accordance with the regeneration mode which is different from the initial setting by later rewriting the flag table FT which is stored in the EEPROM 33, it is not necessary to delete the flag table FT each time, for example, by changing the ROM 32 or rewrite the general-purpose regeneration program GPM, in the case that it is intended to change the regeneration mode. Therefore, it is possible to achieve such an effect of easily coping with the systems of the various working machines. For example, for the customer (the engine buying manufacturer), it is easy to modify a setting to one suitable for its own specification in spite of the engine 70 which is bought externally.
(4) First Embodiment of Loop Process
Next, a description will be given of a first embodiment of a loop process of the DPF regeneration control by the ECU 11 with reference to flow charts in
An algorithm shown by the flow charts in
In the loop process of the first embodiment, first of all, the step discriminates a value of a mode selection flag RGMOD during the flag table FT1 for the self-regeneration which is read from the EEPROM 33 (S11). In the first embodiment, since the value of the mode selection flag RGMOD is “0”, the step calls the subroutine of the self-regeneration mode shown in
(5) Second Embodiment of Loop Process
Next, a description will be given of a second embodiment of the loop process of the DPF regeneration control by the ECU 11 with reference to a flow chart in
In the loop process of the second embodiment, since the value of the mode selection flag RGMOD is “1”, the step calls the subroutine of the automatic auxiliary regeneration mode shown in
If the predetermined time has passed (S304: YES), the step finishes the measurement by the timer 35 so as to turn on the regeneration lamp 24 (S306), and discriminates a value of an intake throttle flag INTSLT in the flag table FT2 for the automatic auxiliary regeneration which is read out of the EEPROM 33 (S307). In the second embodiment, since the intake throttle device 81 is provided and INSTLT=“1” is established, the step closes an opening degree of the intake throttle device 81 to a predetermined opening degree to limit an intake amount to each of the cylinders (S308). Thereafter, the step discriminates a value of an exhaust throttle flag OUTSLT (S309). In the second embodiment, since the exhaust throttle device 82 is provided and OUTSLT=“1” is established, the step closes an opening degree of the exhaust throttle device 82 to a predetermined opening degree to suppress a discharge of the exhaust gas (S310).
Next, the step discriminates a value of a post injection flag APSTINJ (S311). In this case, the post injection means a fuel injection which is carried out after the main injection for feeding a high-pressure fuel to the exhaust route. Since the high-pressure fuel fed to the exhaust route mainly burns the PM within the DPF 50, it is possible to regenerate the DPF 50. In the second embodiment, since the common rail 120 is provided as the fuel injection device and APSTINJ=“1” is established, the post injection is executed by the common rail 120 (S312). As mentioned above, in the automatic regeneration auxiliary mode, the temperature of the exhaust gas is raised by increasing the engine load on the basis of the limit of the intake amount and the exhaust amount, or the PM within the DPF 50 is directly burned by the post injection. As a result, the PM within the DPF 50 is removed, and the PM collecting capacity of the DPF 50 (the soot filter 54) is recovered.
Thereafter, the step returns to the main routine of the loop process, and again discriminates the value of the mode selection flag RGMOD (S15). In this case, since RGMOD=“1” is established, the step calls a subroutine shown in
(6) Third Embodiment of Loop Process
Next, a description will be given of a third embodiment of loop process of the DPF regeneration control by the ECU 11 with reference to a flow chart in
In the loop process in accordance with the third embodiment, since the value of the mode selection flag RGMOD is “2”, the step calls the subroutine of the manual auxiliary regeneration mode shown in
Next, if the regeneration switch 24 is turned on (S404: YES), the step turns on the regeneration lamp 24 (S405), and discriminates the value of the intake throttle flag INTSLT in the flag table FT3 for the manual auxiliary regeneration which is read from the EEPROM 33 (S406). Since the flow of the steps S406 to S411 is the same as the flow of the steps S307 to S312 of the automatic auxiliary regeneration mode which is described in the second embodiment, a detailed description thereof will be omitted. After the step S411, the step returns to the main routine of the loop process, and discriminates again the value of the mode selection flag RGMOD (S15). Since RGMOD=“2” is established in this case, the step calls the subroutine shown in
(7) Summary
As is apparent from the description mentioned above and
Further, it is not necessary to develop the program for regenerating the exhaust gas purifying device 50 per kind of the various working machine, and there is an advantage that it contributes to cost suppression. Further, since the general-purpose regeneration program GPM can be easily switched to one which corresponds to the kind of the working machine only by changing the flag table FT without any special knowledge of a programming, it becomes easy to provide an engine device which meets a customer's (an engine buying manufacture's) demand.
As is apparent from the description mentioned above and
As is apparent from the description mentioned above and
As is apparent from the description mentioned above and
(8) Others
The present invention is not limited to the embodiment mentioned above, but can be specified into various aspects. For example, the fuel injection device of the engine device is not limited to the common rail type, but may be of an electronic governor type. In addition, the structure of each of the portions is not limited to the illustrated embodiment, but can be variously changed in a range which does not deviate from the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-04792 | Mar 2010 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2011/053389 | 2/17/2011 | WO | 00 | 8/29/2012 |
