JP2015017589A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction machine capable of suppressing repeated regeneration performed in a short time.SOLUTION: A regeneration device 22 regenerates a filter 21 by burning particulate matter collected by the filter 21 of an exhaust emission control device 18. The regeneration device 22 estimates a collected amount of the particulate matter collected by the filter 21, and determines whether or not to automatically regenerate the filter 21 with the usage of the estimated collected amount. Further, the regeneration device 22 notifies an operator to manually perform regeneration when an interval A of automatic regeneration is within reference time α [hr] and the number of times B of automatic regeneration performed at the interval within the reference time α is equal to or more than a threshold number of times β [times].

Description

  The present invention relates to a construction machine provided with an exhaust gas purification device that is preferably used to remove harmful substances from exhaust gas such as diesel engines.

  In general, a construction machine such as a hydraulic excavator or a hydraulic crane is capable of a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and an up-and-down movable forward of the upper revolving body. And a working device provided. The upper swing body has an engine for driving a hydraulic pump at the rear of the swing frame, and a cab, a fuel tank, a hydraulic oil tank, and the like are mounted on the front side of the swing frame.

  Here, a diesel engine is generally used as an engine serving as a prime mover for construction machinery. The exhaust gas discharged from such a diesel engine may contain harmful substances such as particulate matter (PM) and nitrogen oxide (NOx). For this reason, in construction machines, an exhaust gas purification device that purifies exhaust gas is provided in an exhaust pipe that forms an exhaust gas passage of the engine.

  An exhaust gas purifying device is an oxidation catalyst (for example, Diesel Oxidation Catalyst, abbreviated as DOC) that oxidizes and removes nitrogen monoxide (NO), carbon monoxide (CO), hydrocarbon (HC), and the like contained in exhaust gas. And a particulate matter removal filter (for example, Diesel Particulate Filter, abbreviated as DPF for short) that is disposed downstream of the oxidation catalyst and collects and removes particulate matter in the exhaust gas. (Patent Document 1).

  By the way, in the particulate matter removing filter, particulate matter accumulates on the filter as the particulate matter is collected, thereby clogging the filter. For this reason, it is necessary to regenerate the filter by removing the particulate matter from the filter when a certain amount of the particulate matter is collected. The regeneration of the filter can be performed by raising the temperature of the exhaust gas by, for example, performing fuel injection for regeneration called post-injection and burning the particulate matter deposited on the filter.

  On the other hand, if the filter is regenerated when particulate matter is excessively deposited (overdeposited) on the filter, the temperature of the exhaust gas becomes excessively high (the combustion temperature of the particulate matter becomes excessively high). The filter may be melted. Therefore, according to the prior art, the amount of particulate matter collected by the filter is estimated (calculated), and before the amount collected becomes excessive, that is, when a preset threshold value is reached. The reproduction is automatically performed (Patent Document 2).

JP 2010-65577 A JP 2000-161044 A

  By the way, filter regeneration is performed when the construction machine is performing a light load operation or when it is left (standby) in a low rotation state (low idle state) where the engine speed (rotation speed) is low. If this is done, the exhaust gas temperature will not rise sufficiently, and the combustion of the particulate matter will automatically end in a slight state. In this case, if the light load work or the low-rotation state standby (leaving) is continued, the regeneration operation and the normal operation are alternately repeated in a short time, and the regeneration frequency increases. This may lead to, for example, an increase in fuel consumption due to an increase in post-injection and an excessive deposition due to insufficient combustion of particulate matter. Furthermore, there is a possibility that the fuel adhering to the cylinder inner wall surface of the engine falls into the oil pan with the post injection, leading to dilution of the engine oil (oil dilution) due to the fuel being mixed into the engine oil.

  Here, when performing regeneration during light-load work or in a low-speed standby state, the engine is automatically controlled to apply a load to the engine from a hydraulic pump, etc., or to increase the engine speed, and exhaust It is conceivable to raise the temperature. However, depending on the operation state, the exhaust gas temperature cannot be sufficiently increased, and the regeneration may be repeatedly performed as described above.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a construction machine that can suppress repeated regeneration in a short time.

  The construction machine of the present invention has a vehicle body on which an operator is boarded, an engine mounted on the vehicle body, and a filter that collects particulate matter in exhaust gas discharged from the engine, on the exhaust side of the engine. An exhaust gas purification device is provided, and a regeneration device that regenerates the filter by burning particulate matter collected by the filter of the exhaust gas purification device.

  And in order to solve the above-mentioned problem, the feature of the configuration adopted by the invention of claim 1 is that the regenerator has a PM calculation means for estimating the amount of particulate matter collected by the filter; , Using the estimated collection amount estimated by the PM calculation means, automatic regeneration determination means for determining whether or not to automatically regenerate the filter, and automatic performed based on the determination of the automatic regeneration determination means There is a configuration including manual regeneration determination means for determining whether to notify the operator to manually perform regeneration based on the frequency of regeneration.

  According to a second aspect of the present invention, the manual regeneration determination unit is configured such that an automatic regeneration interval performed based on the determination of the automatic regeneration determination unit is within a preset reference time and at an interval within the reference time. In this case, the operator is informed that the reproduction is performed manually when the number of times exceeds a predetermined number of times set in advance.

  According to a third aspect of the present invention, the manual regeneration determination unit is configured such that the number of automatic regenerations performed based on the determination of the automatic regeneration determination unit becomes equal to or greater than a predetermined number within a preset number measurement time. In this configuration, the operator is informed to perform manual regeneration.

  According to a fourth aspect of the present invention, the automatic regeneration determination means is configured to terminate automatic regeneration when the exhaust temperature falls below a predetermined temperature after starting automatic regeneration.

  According to a fifth aspect of the present invention, the automatic regeneration determination unit and the manual regeneration determination unit are configured to terminate the regeneration when the estimated collection amount estimated by the PM calculation unit is equal to or less than a preset regeneration end threshold. There is.

  According to the first aspect of the present invention, the manual regeneration determining means for determining whether or not to notify the operator to manually perform regeneration based on the frequency of automatic regeneration performed based on the determination of the automatic regeneration determining means. It is configured to provide. For this reason, for example, during light load work or in a low rotation state standby (left), automatic regeneration is performed based on the determination of the automatic regeneration determination means, and the exhaust temperature does not rise sufficiently, so that regeneration is short. When it tends to be repeatedly performed in time (the frequency increases), the manual regeneration determination means informs the operator to perform regeneration manually.

  In this case, the manual regeneration based on the operator's operation is regeneration performed with the intention (intention) of performing the regeneration of the operator. For example, the exhaust temperature is increased sufficiently by increasing the engine speed. Can be done. Thereby, the particulate matter collected by the filter can be sufficiently burned and removed, and the regeneration can be suppressed from being repeated repeatedly in a short time. As a result, it is possible to reduce fuel consumption (low fuel consumption), suppress excessive accumulation, and suppress dilution of engine oil (oil dilution) due to fuel mixing into engine oil, As a result, the stability and reliability of the construction machine can be improved.

  According to the invention of claim 2, when the automatic regeneration interval is within the reference time and the number of times performed at the interval within the reference time is equal to or greater than the predetermined number, the operator manually performs the regeneration. It is set as the structure which alert | reports so that it may perform. For this reason, it can be stably determined that the automatic reproduction tends to be repeated based on the interval and the number of automatic reproduction. Thus, when manual regeneration is to be performed (when manual regeneration is necessary), the operator can be surely notified.

  According to the third aspect of the present invention, when the number of times of automatic regeneration becomes equal to or greater than a predetermined number within the number-of-times measurement time, the operator is informed to perform manual regeneration. For this reason, it can be stably determined that the automatic reproduction tends to be repeatedly performed based on the number of automatic reproductions within the number measurement time. Thus, when manual regeneration is to be performed (when manual regeneration is necessary), the operator can be surely notified.

  According to the invention of claim 4, the automatic regeneration determination means is configured to terminate the automatic regeneration when the exhaust gas temperature becomes lower than a predetermined temperature after the automatic regeneration is started. For this reason, when the exhaust temperature is low and sufficient combustion of the particulate matter cannot be expected, the increase in fuel consumption and oil dilution can be suppressed by terminating the automatic regeneration. On the other hand, even if the interval until the next automatic regeneration is shortened by ending automatic regeneration, the manual regeneration determining means informs the operator to perform manual regeneration, and manual regeneration is performed. For this reason, it is possible to suppress both the automatic regeneration being continued while the exhaust temperature is low and the repeated automatic regeneration. Thereby, reduction of fuel consumption (low fuel consumption), suppression of excessive deposition, and suppression of oil dilution can be achieved at a high level.

  According to the invention of claim 5, the automatic regeneration determination means and the manual regeneration determination means are configured to terminate the regeneration when the estimated collection amount estimated by the PM calculating means is equal to or less than the regeneration end threshold. For this reason, by setting the regeneration end threshold value small, the amount of particulate matter (residual amount) of the filter immediately after regeneration can be reduced, and the interval until the next regeneration can be lengthened. On the other hand, if the regeneration end threshold is set to a small value, during automatic regeneration, for example, if the particulate matter does not burn sufficiently due to low exhaust temperature, it takes a long time to fall below the regeneration end threshold, or regeneration. It may not be less than the end threshold.

  Even in this case, when other conditions are satisfied, for example, when the exhaust gas temperature becomes lower than a predetermined temperature, the automatic regeneration is terminated so that the automatic regeneration is continued with the exhaust gas temperature being low. Can be suppressed. In this case, since the automatic reproduction ends before the reproduction end threshold or less, the interval until the next automatic reproduction is shortened, but even if this interval is shortened, if it continues, the manual regeneration determination means The operator is notified to perform manual regeneration, and manual regeneration is performed. For this reason, it is possible to prevent the automatic regeneration from being continued and the automatic regeneration from being repeatedly performed while ensuring that the interval until the next regeneration is increased, while the exhaust temperature is low.

It is a front view which shows the hydraulic shovel applied to the 1st Embodiment of this invention. FIG. 2 is a partially cutaway plan view showing the hydraulic excavator in an enlarged manner with the cab and part of the outer cover removed from the upper swing body in FIG. 1. It is a circuit block diagram which shows an engine, an exhaust-gas purification apparatus, a regeneration apparatus, etc. It is a flowchart which shows the reproduction | regeneration process of the filter by a reproducing | regenerating apparatus. FIG. 5 is a flowchart showing “manual regeneration processing” in step 8 in FIG. 4. FIG. It is a characteristic diagram which shows an example of the time change of an estimated collection amount. It is a circuit block diagram which shows the engine by the 2nd Embodiment of this invention, an exhaust-gas purification apparatus, a regeneration apparatus, etc. It is a characteristic diagram which shows an example of the time change of the estimated collection amount by a modification.

  Hereinafter, a construction machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the construction machine is applied to a small hydraulic excavator called a mini excavator.

  1 to 6 show a first embodiment of the present invention. In the figure, 1 is a small hydraulic excavator used for excavation work of earth and sand. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2, and is mounted on the lower traveling body 2 through a turning device 3 so as to be capable of turning. The main body 4 and a work device 5 provided so as to be able to move up and down on the front side of the upper swing body 4 are roughly configured.

  Here, the working device 5 is configured as a swing post type working device, for example, a swing post 5A, a boom 5B, an arm 5C, a bucket 5D as a working tool, and a swing cylinder 5E that swings the working device 5 left and right. (Refer to FIG. 2), a boom cylinder 5F, an arm cylinder 5G, and a bucket cylinder 5H are provided. The upper swing body 4 includes a swing frame 6, an exterior cover 7, a cab 8, and a counterweight 9 which will be described later.

  The turning frame 6 forms a structure of the upper turning body 4, and the turning frame 6 is mounted on the lower traveling body 2 via the turning device 3. The revolving frame 6 is provided with a counterweight 9 and an engine 10 which will be described later on the rear side, a cab 8 which will be described later on the left front side, and a fuel tank 16 which will be described later on the right front side. The revolving frame 6 is provided with an exterior cover 7 extending from the right side to the rear side of the cab 8, and this exterior cover 7 together with the revolving frame 6, the cab 8 and the counterweight 9, the engine 10, the hydraulic pump 15, and the heat exchanger 17. A space for accommodating the fuel tank 16, the exhaust gas purification device 18 and the like is defined.

  The cab 8 is mounted on the left front side of the revolving frame 6, and the cab 8 defines a cab in which an operator is boarded. Inside the cab 8, in addition to a driver's seat on which an operator is seated, various operation levers, an alarm device 27 and a manual regeneration switch 28 (all of which are shown in FIG. 3), which will be described later, are disposed.

  The counterweight 9 balances the weight of the work device 5, and the counterweight 9 is attached to the rear end portion of the turning frame 6 so as to be positioned on the rear side of the engine 10 described later. As shown in FIG. 2, the rear surface side of the counterweight 9 is formed in an arc shape, and the counterweight 9 is configured to fit within the vehicle body width of the lower traveling body 2.

  Reference numeral 10 denotes an engine that is disposed horizontally on the rear side of the revolving frame 6. Since the engine 10 is mounted as a prime mover on the small hydraulic excavator 1, for example, a small diesel engine is used. The engine 10 is provided with an intake pipe 11 (see FIG. 3) for sucking outside air and an exhaust pipe 12 forming a part of an exhaust gas passage for discharging exhaust gas. The intake pipe 11 is for the outside air (air) to flow toward the engine 10, and an air cleaner 13 for cleaning the outside air is connected to the front end side of the intake pipe 11. An exhaust gas purification device 18 to be described later is connected to the exhaust pipe 12.

  Here, the engine 10 is composed of an electronically controlled engine, and the amount of fuel supplied is variably controlled by a fuel injection device 14 (see FIG. 3) such as an electronically controlled injection valve. That is, the fuel injection device 14 variably controls the injection amount (fuel injection amount) of fuel injected into a cylinder (not shown) of the engine 10 based on a control signal output from a controller 29 described later. .

  Further, the fuel injection device 14 constitutes a regeneration device 22 (see FIG. 2) together with a controller 29 and the like which will be described later. The fuel injection device 14 performs a regeneration process called post injection, for example, according to a control signal of the controller 29. Fuel injection (additional injection after the combustion process). Thereby, the temperature of the exhaust gas is raised, and the particulate matter deposited on the particulate matter removal filter 21 of the exhaust gas purification device 18 described later is burned and removed.

  The hydraulic pump 15 is attached to the left side of the engine 10, and the hydraulic pump 15 constitutes a hydraulic source together with a hydraulic oil tank (not shown). The hydraulic pump 15 discharges pressure oil (hydraulic oil) toward a control valve (not shown) by being driven by the engine 10. The hydraulic pump 15 is configured by, for example, a variable displacement swash plate type, a swash shaft type, or a radial piston type hydraulic pump. The hydraulic pump 15 is not necessarily limited to a variable displacement hydraulic pump, and may be configured using, for example, a fixed displacement hydraulic pump.

  The fuel tank 16 is located on the right side of the cab 8 and is provided on the revolving frame 6 and is covered with the exterior cover 7 together with a hydraulic oil tank (not shown). The fuel tank 16 is formed as, for example, a substantially rectangular parallelepiped pressure-resistant tank, and stores fuel supplied to the engine 10.

  The heat exchanger 17 is provided on the turning frame 6 on the right side of the engine 10, and the heat exchanger 17 includes, for example, a radiator, an oil cooler, and an intercooler. That is, the heat exchanger 17 cools the engine 10 and also cools the pressure oil (working oil) returned to the working oil tank.

  Next, the exhaust gas purification device 18 that purifies the exhaust gas discharged from the engine 10 will be described.

  That is, reference numeral 18 denotes an exhaust gas purification device provided on the exhaust side of the engine 10. As shown in FIG. 2, the exhaust gas purification device 18 is disposed on the upper left side of the engine 10, for example, at a position above the hydraulic pump 15, and the exhaust pipe 12 of the engine 10 is connected to the upstream side thereof. . The exhaust gas purification device 18 constitutes an exhaust gas passage together with the exhaust pipe 12, and removes harmful substances contained in the exhaust gas while the exhaust gas flows from the upstream side to the downstream side.

  That is, the engine 10 made of a diesel engine has high efficiency and excellent durability. However, the exhaust gas of the engine 10 contains harmful substances such as particulate matter (PM), nitrogen oxides (NOx), and carbon monoxide (CO). For this reason, as shown in FIG. 3, an exhaust gas purification device 18 attached to the exhaust pipe 12 includes an oxidation catalyst 20 (to be described later) that oxidizes and removes carbon monoxide (CO) and the like in the exhaust gas, The particulate matter removal filter 21 described later for collecting and removing the particulate matter (PM) is included.

  As shown in FIG. 3, the exhaust gas purification device 18 includes a cylindrical casing 19 configured by detachably connecting a plurality of cylindrical bodies, for example, before and after. In the casing 19, an oxidation catalyst 20 and a particulate matter removing filter 21 (hereinafter referred to as a filter 21) as a filter are detachably accommodated.

The oxidation catalyst 20 is made of a ceramic cylindrical tube having an outer diameter dimension equivalent to the inner diameter dimension of the casing 19, for example. A large number of through holes (not shown) are formed in the oxidation catalyst 20 in the axial direction, and the inner surface thereof is coated with a noble metal. The oxidation catalyst 20 oxidizes and removes carbon monoxide (CO), hydrocarbon (HC), etc. contained in the exhaust gas by circulating the exhaust gas through each through hole under a predetermined temperature condition. Then, nitrogen oxide (NO) is removed as nitrogen dioxide (NO ₂ ).

  On the other hand, the filter 21 is disposed in the casing 19 on the downstream side of the oxidation catalyst 20. The filter 21 collects particulate matter in the exhaust gas discharged from the engine 10 and purifies the exhaust gas by burning and removing the collected particulate matter. For this purpose, the filter 21 is constituted by a cellular cylindrical body in which a large number of small holes (not shown) are provided in the axial direction on a porous member made of, for example, a ceramic material. Thus, the filter 21 collects the particulate matter through a large number of small holes, and the collected particulate matter is burned and removed by a regeneration process of the regeneration device 22 described later. As a result, the filter 21 is regenerated.

  Next, the regenerator 22 that regenerates the filter 21 will be described.

  That is, reference numeral 22 denotes a regenerator that regenerates the filter 21 by burning particulate matter collected by the filter 21 of the exhaust gas purification device 18. The regeneration device 22 includes the fuel injection device 14 described above, a rotation sensor 23, pressure sensors 24 and 25, an exhaust temperature sensor 26, an alarm device 27, a manual regeneration switch 28, and a controller 29, which will be described later. The regeneration device 22 performs post injection by the fuel injection device 14 in accordance with a command signal (control signal) from the controller 29. Thereby, as will be described later, the temperature of the exhaust gas in the exhaust pipe 12 is raised, and the particulate matter deposited on the filter 21 is burned and removed.

  Here, the reproducing device 22 automatically reproduces automatically by the determination of the controller 29, that is, automatically based on the operation of the operator, and manually reproduces the operator by the determination of the controller 29. And a manual regeneration function for performing regeneration based on the operation of the operator.

  The rotation sensor 23 detects the rotation speed (rotation speed) N of the engine 10. The rotation sensor 23 detects the rotation speed N of the engine 10 and outputs a detection signal to a controller 29 described later. The controller 29, for example, the engine speed N detected by the rotation sensor 23, the fuel injection amount F injected by the fuel injection device 14, and the exhaust temperature (exhaust gas temperature) T detected by the exhaust temperature sensor 26 described later. Based on the above, the amount of particulate matter collected by the filter 21 is estimated, and whether to regenerate is determined based on the first estimated amount of collection H1, which is the estimated amount of collection. Do. The fuel injection amount F can be obtained from, for example, an intake air amount detected from an air flow meter (air flow meter) (not shown) provided on the intake side of the engine 10 and the engine speed N. It can also be calculated from a control signal (fuel injection command) output from 29 to the fuel injection device 14.

  The pressure sensors 24 and 25 are provided in the casing 19 of the exhaust gas purification device 18. As shown in FIG. 3, the pressure sensors 24 and 25 are arranged on the inlet side (upstream side) and the outlet side (downstream side) of the filter 21 so as to be separated from each other, and output respective detection signals to the controller 29 described later. To do. The controller 29 calculates a differential pressure ΔP based on the inlet side pressure P 1 detected by the pressure sensor 24 and the outlet side pressure P 2 detected by the pressure sensor 25, and also calculates the differential pressure ΔP, the exhaust temperature T, and the exhaust gas flow rate. Based on this, the amount of particulate matter collected by the filter 21 is estimated, and based on the second estimated amount of collection H2, which is the estimated amount of collection, it is determined whether or not regeneration is to be performed. .

  The exhaust temperature sensor 26 detects an exhaust temperature (exhaust gas temperature) T. As shown in FIG. 3, the exhaust temperature sensor 26 is attached to the casing 19 of the exhaust gas purification device 18 and detects the temperature T of exhaust gas discharged from the exhaust pipe 12 side, for example. The exhaust temperature T upstream of the filter 21 detected by the exhaust temperature sensor 26 is output as a detection signal to the controller 29 described later. The exhaust gas temperature T is used for estimating the amount of particulate matter collected by the filter 21 and determining the end of automatic regeneration.

  The alarm device 27 is provided in the vicinity of the driver's seat in the cab 8. The notification device 27 is connected to the controller 29 and notifies the operator to perform manual regeneration based on a command (notification signal) from the controller 29. Here, the notification device 27 can be configured by a buzzer for generating a notification sound, a speaker for generating a sound, a light or a monitor for displaying notification contents, and the like. When the controller 29 determines that it is necessary to perform manual regeneration, the notification device 27 generates a notification sound and a notification display to that effect on the basis of a command (notification signal) from the controller 29.

  The manual regeneration switch 28 is provided in the cab 8 near the driver's seat. The manual regeneration switch 28 is connected to a controller 29 which will be described later, and outputs a signal for performing regeneration (manual regeneration) to the controller 29 based on the operation of the operator. That is, when the operator operates the manual regeneration switch 28 by notification from the notification device 27 (notification of manual regeneration), a signal indicating that the switch has been operated is output from the manual regeneration switch 28 to the controller 29. As a result, the controller 29 outputs a command (control signal) for performing regeneration (post-injection) to the fuel injection device 14, thereby performing manual regeneration (manual regeneration) by the operator. Yes.

  The controller 29 is composed of a microcomputer or the like, and the controller 29 has a fuel injection device 14, a rotation sensor 23, pressure sensors 24 and 25, an exhaust temperature sensor 26, a manual regeneration switch 28, an air flow meter (air flow rate not shown) on the input side. Etc.). The output side of the controller 29 is connected to the fuel injection device 14, the alarm 27, and the like. The controller 29 has a storage unit 29A composed of a ROM, a RAM, and the like. In this storage unit 29A, a processing program for regeneration processing shown in FIGS. First map, second map, calculation formula, reproduction start threshold value Ht [g / l], reproduction end threshold value He [g / l] shown in FIG. α [hr], the number threshold β [times], and the like are stored. Further, the storage unit 29A stores an automatic reproduction interval A [hr], which will be described later, and an automatic reproduction number B [times].

  Here, the first map is for obtaining the discharge amount Hm of the particulate matter discharged from the engine 10 based on the rotational speed N of the engine 10 and the fuel injection amount F. Specifically, the first map is obtained by, for example, obtaining a correspondence relationship between the engine speed N, the fuel injection amount F, and the particulate matter discharge amount Hm in advance through experiments, calculations, simulations, etc. It was created. The calculation formula for estimating the trapped amount is that the first estimated trapped amount is H1, the particulate matter discharge amount obtained from the first map is Hm, and particles removed from the filter 21 by regeneration. When the amount of the substance (regeneration amount) is J, it can be expressed as the following formula 1.

In this case, the amount of particulate matter removed by regeneration, that is, the regeneration amount J is, for example, the exhaust gas flow rate obtained from the engine speed N and the fuel injection amount F, the exhaust temperature T, and the engine speed. It can be calculated from the relationship with the NO ₂ conversion rate obtained by adding the exhaust gas temperature T to the nitrogen oxide (NOx) emission amount obtained from N and the fuel injection amount F.

  On the other hand, the second map is for estimating the collection amount based on the differential pressure ΔP of the filter 21. Specifically, the second map is obtained, for example, by previously obtaining a correspondence relationship between the differential pressure ΔP, the flow rate of the exhaust gas, and the second estimated trapped amount H2 through experiments, calculations, simulations, and the like, and maps the correspondence relationship. It was created as. The flow rate of the exhaust gas can be obtained from, for example, the engine speed N and the fuel injection amount F. The differential pressure ΔP of the filter 21 is calculated by the following formula 2 when the inlet side pressure detected by the pressure sensor 24 is P1 and the outlet side pressure P2 detected by the pressure sensor 25 is used.

  Next, as will be described with reference to FIG. 6, the regeneration start threshold value Ht [g / l] is a threshold value of the estimated collection amount H for determining whether or not to perform automatic regeneration. That is, the regeneration start threshold value Ht is the first estimated collection amount H1 estimated by the above-mentioned first map and the calculation formula and / or the second estimated collection estimated by the above-mentioned second map. When the amount H2 is equal to or greater than the regeneration start threshold value Ht, this is a determination value for determining that automatic regeneration is necessary. In other words, the regeneration start threshold Ht is a determination value for determining whether or not the particulate matter collected by the filter 21 has reached a collection amount necessary for the regeneration process of the filter 21. Therefore, the regeneration start threshold value Ht is a value based on experiments, calculations, simulations, etc. in advance so that the regeneration process can be performed in an appropriate state, for example, in a state where sufficient particulate matter is collected in the filter 21. Set. Thereby, when the particulate matter is sufficiently collected by the filter 21, the regeneration process can be stably performed by the regeneration device 22.

  On the other hand, the regeneration end threshold value He [g / l] is a threshold value of the estimated collection amount H for determining whether or not to end the regeneration. That is, the regeneration end threshold value He is the first estimated collection amount H1 estimated by the above-described first map and calculation formula and / or the second estimated collection estimated by the above-mentioned second map. When the amount H2 becomes equal to or less than the regeneration end threshold value He, it becomes a determination value for determining that the particulate matter of the filter 21 has been sufficiently burned and removed. In other words, the regeneration end threshold value He is a determination value for determining whether or not the amount of particulate matter in the filter 21 has been reduced to an allowable residual amount when particulate matter is burned and removed by regeneration. For example, the smaller the regeneration end threshold value He is set, the greater the amount of particulate matter that can be collected by the filter 21 before the next regeneration. That is, the smaller the reproduction end threshold value He is set, the longer the interval until the next reproduction can be made. Therefore, the value of the regeneration end threshold value He is set in advance based on experiments, calculations, simulations, etc. so that the regeneration can be terminated at an appropriate time.

  Furthermore, the reference time α [hr] and the frequency threshold value β [times] are determination values for determining whether or not automatic regeneration is repeatedly performed in a short time. That is, the reference time α and the number of times threshold β are the number of times that the automatic reproduction interval A is within a preset reference time α and the number of times B performed at an interval within the reference time α is a preset predetermined number of times. When the threshold value β is equal to or greater than the threshold value β, the determination value is determined to determine that automatic regeneration and normal operation are repeatedly performed in a short time. The reference time α and the number of times threshold β appropriately indicate that the automatic regeneration is repeatedly performed without the exhaust temperature T sufficiently rising by continuing the light load work or the low-speed state standby (leaving). The value is set in advance based on experiments, calculations, simulations, etc. so that the determination can be made.

  The controller 29 controls the automatic regeneration processing for automatically performing the regeneration without being based on the operation of the operator and notifies the operator to perform the regeneration manually in accordance with the processing programs of FIGS. Control of manual regeneration processing for performing regeneration based on the above operation.

  That is, the controller 29 estimates the amount of particulate matter collected by the filter 21 (PM calculation means). The amount of collection can be estimated based on at least the engine speed N, the fuel injection amount F, and the exhaust temperature T (first estimation means). Further, the amount of collection can be estimated based on at least the differential pressure ΔP of the filter 21 (second estimation means). The collection amount can be estimated using either one of the first estimation means and the second estimation means, or both. Depending on the driving situation, a highly accurate estimation means at that time may be used. Furthermore, the trapped amount of the particulate matter may be estimated using an estimation means other than the first and second estimation means.

  In any case, when the estimated collection amount is the estimated collection amount H, the controller 29 determines whether or not the filter 21 is automatically regenerated using the estimated collection amount H (automatically). Reproduction determination means). For example, the controller 29 determines the estimated collection amount H, more specifically, the first estimated collection amount H1 estimated by the first estimation means and the second estimated capture amount estimated by the second estimation means. Whether or not automatic regeneration is to be performed can be determined based on whether or not at least one of the collected amounts H2 is equal to or greater than the regeneration start threshold Ht. When the controller 29 determines that automatic regeneration is necessary (becomes the regeneration start threshold value Ht or more), for example, the controller 29 outputs a control signal indicating post-injection to the fuel injection device 14 without any operator operation. Controls automatic playback processing that automatically plays back.

  Here, in the automatic regeneration process, after the automatic regeneration is started, the estimated collection amount H (at least one of the first estimated collection amount H1 and the second estimated collection amount H2) When the playback end threshold value He is set or less, the playback ends. In addition, in the automatic regeneration process, after the automatic regeneration is started, when the exhaust temperature T becomes lower than a predetermined temperature set in advance, that is, the exhaust temperature threshold value Tt, the estimated collection amount H (first estimated collection amount). Even if the amount H1 and the second estimated collection amount H2) are not less than or equal to the regeneration end threshold value He, the automatic regeneration is terminated. Even if the regeneration process is continued while the exhaust temperature T is low, the particulate matter cannot be sufficiently burned and removed, and the fuel consumption increases due to post injection, whereas the particulate matter is burned and removed. This is to prevent the state from progressing. The exhaust gas temperature threshold value Tt is set in advance based on experiments, calculations, simulations, and the like so as to be, for example, a boundary value of the exhaust gas temperature T that can obtain an efficiency acceptable for regeneration.

  By the way, in the regeneration, when the exhaust gas temperature T is sufficiently high, as shown by a two-dot chain characteristic line 30 in FIG. 6, the estimated collection amount H (first estimated collection amount H1, second estimated collection amount). The process is performed until the collection amount H2) becomes equal to or less than the regeneration end threshold value He. On the other hand, automatic regeneration is performed, for example, when a light load operation is performed, or when the engine 10 is left (standby) in a low rotation state (low idle state) where the rotation speed (rotation speed) N of the engine 10 is low. Then, since the exhaust temperature T does not rise sufficiently, the combustion of the particulate matter is automatically terminated in a slight state as shown by the solid characteristic line 31 in FIG. In this case, if the light load operation or the low-rotation state standby (leaving) is continued, the state where the automatic regeneration and the normal operation are alternately repeated in a short time is continued, and the frequency of the automatic regeneration increases. Then, as shown by the two-dot chain characteristic line 32 in FIG. 6, if the repetition of the automatic regeneration and the normal operation continues excessively, for example, the fuel consumption increases due to the increase in post injection, the combustion of the particulate matter May lead to over-deposition due to insufficient. Furthermore, there is a possibility that the fuel adhering to the cylinder inner wall surface of the engine falls into the oil pan with the post injection, leading to dilution of the engine oil (oil dilution) due to the fuel being mixed into the engine oil.

  Therefore, in the present embodiment, the controller 29 determines whether to notify the operator to perform manual regeneration based on the frequency of automatic regeneration (manual regeneration determination means). When the frequency of automatic regeneration becomes high and it is determined that manual regeneration is necessary, the controller 29 notifies the operator to perform regeneration manually. More specifically, the controller 29 performs the automatic reproduction interval A (A1, A2, A3, A4 in FIG. 6) within a preset reference time α and at intervals within the reference time α. When the number B of automatic regeneration (the number of times B1, B2, B3, and B4 in FIG. 6) is equal to or greater than a preset number of times threshold β, the controller 29 requires manual regeneration (automatic regeneration processing is performed). It is determined that the signal is not normal, and a signal (notification signal) for informing the operator to perform manual regeneration is output to the notification device 27. As a result, a notification sound and a notification display are generated from the notification device 27, the operator operates the manual regeneration switch 28, and the controller 29 controls the manual regeneration processing for performing regeneration on the condition of the operator's operation.

  Here, since the manual regeneration process is performed under the intention (consciousness) of performing the regeneration by the operator, it can be performed, for example, by increasing the engine speed N and increasing the exhaust temperature T. In this case, if necessary, the operator does not perform the operation (the operation is mainly performed for regeneration). As a result, as shown by the solid characteristic line 33 in FIG. 6, the particulate matter collected by the filter 21 can be sufficiently burned and removed, and the regeneration is prevented from being repeated repeatedly in a short time. can do. Similarly to the automatic regeneration process, the manual regeneration process is started after the regeneration, and then the estimated collection amount H (at least one of the first estimated collection amount H1 and the second estimated collection amount H2). ) Is equal to or less than a preset reproduction end threshold value He, the reproduction is terminated. The reproduction process shown in FIGS. 4 and 5 executed by the controller 29 including the manual reproduction process and the automatic reproduction process described above will be described later.

  The exhaust port 34 is provided on the downstream side of the exhaust gas purification device 18, and the exhaust port 34 is located on the downstream side of the filter 21 and connected to the outlet side of the casing 19. The discharge port 34 includes, for example, a chimney and a silencer that discharges exhaust gas after being purified into the atmosphere.

  The hydraulic excavator 1 according to the first embodiment has the above-described configuration, and the operation thereof will be described next.

  The operator of the hydraulic excavator 1 gets on the cab 8 of the upper swing body 4, starts the engine 10, and drives the hydraulic pump 15. Thereby, the pressure oil from the hydraulic pump 15 is supplied to various actuators via the control valve. When the operator who has boarded the cab 8 operates the operating lever for traveling, the lower traveling body 2 can be moved forward or backward.

  On the other hand, when the operator in the cab 8 operates the operation lever for work, the work device 5 can be moved up and down to perform excavation work of earth and sand. In this case, since the small excavator 1 has a small turning radius by the upper swing body 4, for example, even in a narrow work site such as an urban area, a side ditching operation or the like can be performed while the upper swing body 4 is driven to rotate.

  During operation of the engine 10, particulate matter, which is a harmful substance, is discharged from the exhaust pipe 12. At this time, the exhaust gas purification device 18 can oxidize and remove hydrocarbon (HC), nitrogen oxide (NO), and carbon monoxide (CO) in the exhaust gas by the oxidation catalyst 20. The filter 21 collects particulate matter contained in the exhaust gas. Thereby, the purified exhaust gas can be discharged to the outside through the downstream discharge port 34. Further, the collected particulate matter is burned and removed (regenerated) by the regenerator 22.

  Next, playback processing performed by the playback device 22 will be described with reference to the flowcharts of FIGS. 4 and 5. 4 and 5 are repeatedly executed by the controller 29 every predetermined control time (at a predetermined sampling frequency) while the controller 29 is energized.

  When the accessory is turned ON or the engine 10 is started (ignition is turned ON), the controller 29 is energized. When the processing operation of FIG. 4 is started, in step 1, the amount of trapped particulate matter is estimated. The estimation of the collected amount can be performed, for example, by at least one of the following (a) and (b).

  (A). Based on the engine speed N of the engine 10, the fuel injection amount F injected from the fuel injection device 14, and the exhaust temperature T of the exhaust gas discharged from the engine 10, the particulate matter collected by the filter 21 The amount collected, that is, the first estimated amount H1 is estimated (calculated).

  (B) Based on the pressure difference ΔP of the filter 21, the amount of particulate matter collected by the filter 21, that is, the second estimated amount of collection H 2 is estimated (calculated).

  Here, the first estimated collection amount H1 in (a) can be estimated using the first map and the calculation formula stored in the storage unit 29A of the controller 29. That is, the total amount of emissions from the start of operation to the present time is obtained by calculating the discharge amount per unit time from the engine speed N and the fuel injection amount F using the above-mentioned first map and integrating the discharge amount. The amount Hm is determined. Based on the above equation 1, the first estimated amount of collection H1 at the present time is obtained by subtracting the amount (regeneration amount) J of the particulate matter removed in the regeneration process up to the present time from the total emission amount Hm. Can be estimated. The engine speed N is read from the rotation sensor 23. The fuel injection amount F can be obtained from, for example, an intake air amount detected from an air flow meter (air flow meter) (not shown) provided on the intake side of the engine 10 and the engine speed N. For example, from the controller 29 It can also be calculated from a control signal (fuel injection command) output to the fuel injection device 14. The exhaust temperature T is read from the exhaust temperature sensor 26.

  The second estimated collection amount H2 in (b) can be estimated using the above-described second map stored in the storage unit 29A of the controller 29. That is, the current second estimated collection amount H2 can be estimated based on the second map in which the differential pressure ΔP, the exhaust gas flow rate, and the estimated collection amount H1 are associated with each other. The differential pressure ΔP is calculated from the pressure P1 upstream of the filter 21 read from the pressure sensor 24 and the downstream pressure P2 read from the pressure sensor 25 using the above equation (2). Can do.

  If the estimated collection amount H (at least one of the first estimated collection amount H1 and the second estimated collection amount H2) is obtained (calculated) in step 1, the process proceeds to step 2. In step 2, it is determined whether or not automatic reproduction is performed. Specifically, for example, depending on whether or not the estimated collection amount H (the first estimated collection amount H1 and / or the second estimated collection amount H2) is equal to or greater than a preset regeneration start threshold value Ht. It is determined whether or not to perform reproduction. If it is determined in step 2 that “NO”, that is, the estimated collection amount H (both estimated collection amounts H1, H2) is smaller than the regeneration start threshold value Ht, the filter 21 needs to be regenerated. It is considered that particulate matter is not collected (the filter 21 is not clogged). In this case, the process returns to before step 1 and the processes after step 1 are repeated.

  On the other hand, if it is determined in step 2 that “YES”, that is, the estimated collection amount H (at least one of the estimated collection amounts H1, H2) is equal to or greater than the regeneration start threshold value Ht, the regeneration of the filter 21 is performed. It is considered that the particulate matter is collected in the filter 21 to the extent that is necessary. Therefore, in this case, the process proceeds to Step 3. In step 3, it is determined whether automatic regeneration should be performed or manual regeneration should be performed. That is, in step 3, it is determined whether or not the automatic reproduction interval A is within the reference time α and the number of automatic reproductions B performed at intervals within the reference time α is equal to or greater than the number threshold β.

  If it is determined in step 3 that “NO”, that is, the automatic reproduction interval A is not within the reference time α or the number of times B performed at the interval within the reference time α is not equal to or greater than the number threshold β, manual It is considered that the frequency of automatic reproduction is not increased as the reproduction is performed. In this case, the process proceeds to step 4 to start automatic reproduction. That is, in step 4, a control signal indicating that post injection is performed from the controller 29 to the fuel injection device 14 is output. As a result, the temperature of the exhaust gas from the engine 10 (exhaust temperature T) is raised, and the particulate matter collected (deposited) on the filter 21 is burned and removed.

  In the subsequent step 5, it is determined based on the exhaust temperature T whether or not the automatic regeneration should be terminated. That is, if the regeneration process is continued while the exhaust temperature T is low, the fuel consumption increases due to post-injection, but the particulate matter may not be burned or removed. Therefore, in step 5, it is determined whether or not the exhaust temperature T is equal to or higher than the exhaust temperature threshold Tt. The exhaust temperature T is read from the exhaust temperature sensor 26.

  If “NO” in step 5, that is, if it is determined that the exhaust gas temperature T is lower than the exhaust gas temperature threshold value Tt, the automatic regeneration is terminated. And it returns to before step 1, and repeats the process after step 1. On the other hand, if “YES” in step 5, that is, if it is determined that the exhaust temperature T is equal to or higher than the exhaust temperature threshold Tt, the process proceeds to step 6. In step 6, the amount of trapped particulate matter is estimated as in step 1 described above. In the subsequent step 7, based on the estimated collection amount H (at least one of the first estimated collection amount H 1 and the second estimated collection amount H 2) obtained (estimated) in step 6, automatic It is determined whether or not to end the reproduction. That is, in step 7, for example, whether the estimated collection amount H (the first estimated collection amount H1 and / or the second estimated collection amount H2) is equal to or less than a preset regeneration end threshold value He, It is determined whether or not to end automatic playback.

  If it is determined in step 7 that “NO”, that is, the estimated collection amount H (both estimated collection amounts H1, H2) is larger than the regeneration end threshold value He, the particulate matter burned and removed by regeneration. In other words, it is considered that the amount of particulate matter remaining in the filter 21 is large. In this case, the process returns to the step 5 and the processes after the step 5 are repeated. On the other hand, if “YES” in step 7, that is, if the estimated collection amount H (at least one of the estimated collection amounts H1, H2) is less than or equal to the regeneration end threshold value He, the automatic regeneration process performs the filter 21. It is thought that the particulate matter was burned and removed sufficiently. In this case, the automatic reproduction is terminated, the process returns to the start via the return, and the processes after step 1 are repeated.

  On the other hand, in step 3, “YES”, that is, it is determined that the automatic reproduction interval A is within the reference time α and the automatic reproduction number B performed at an interval within the reference time α is equal to or greater than the number threshold β. In such a case, the frequency of automatic regeneration is high, and it is considered necessary to perform manual regeneration. In this case, the process proceeds to the manual regeneration process in step 8.

  The manual regeneration process of step 8 is the process of steps 11 to 16 shown in FIG. That is, in step 11, it is assumed that the automatic regeneration process is not normal because the frequency of automatic regeneration is high, and in step 12, manual regeneration is requested to the operator. That is, in step 12, the controller 29 outputs a notification signal indicating that a notification sound, a notification display or the like is issued to the notification device 27, and notifies the operator to manually perform reproduction.

  In the following step 13, it is determined whether or not manual regeneration is to be started. This determination can be made, for example, based on whether or not a signal indicating that the switch has been operated is output from the manual regeneration switch 28 to the controller 29 when the operator operates the manual regeneration switch 28. If it is determined in step 13 that “NO”, that is, a signal indicating that the manual regeneration switch 28 has not yet been operated is output, the process returns to step 12 and the processes in and after step 12 are repeated. On the other hand, if it is determined in step 13 that “YES”, that is, a signal indicating that the manual regeneration switch 28 has been operated is output, the process proceeds to step 14 where manual regeneration is started. In step 14, a control signal indicating that post injection is performed from the controller 29 to the fuel injection device 14 is output. In this case, the rotational speed N of the engine 10 is increased as necessary. As a result, the temperature of the exhaust gas from the engine 10 (exhaust temperature T) is raised, and the particulate matter collected (deposited) on the filter 21 is burned and removed.

  In step 15, the amount of trapped particulate matter is estimated as in steps 1 and 6 described above. In the subsequent step 16, manual operation is performed based on the estimated collection amount H (at least one of the first estimated collection amount H 1 and the second estimated collection amount H 2) obtained (estimated) in step 15. It is determined whether or not to end the reproduction. That is, in step 16, for example, whether or not the estimated collection amount H (first estimated collection amount H1 and / or second estimated collection amount H2) is equal to or less than a preset regeneration end threshold value He, It is determined whether or not to end the manual regeneration.

  If it is determined in step 16 that “NO”, that is, the estimated collection amount H (both estimated collection amounts H1, H2) is larger than the regeneration end threshold value He, the particulate form burned and removed by manual regeneration. It is considered that the amount of the substance is not yet sufficient, in other words, the amount of the particulate matter remaining in the filter 21 is large. In this case, the process returns to before step 15, and the processes after step 15 are repeated. On the other hand, if “YES” is determined in step 16, that is, if the estimated collection amount H (at least one of the estimated collection amounts H 1 and H 2) is equal to or less than the regeneration end threshold value He, the filter 21 is manually regenerated. It is thought that the particulate matter was burned and removed sufficiently. In this case, the manual regeneration is terminated, the process returns to the start via the return of FIG. 5 and the return of FIG. 4, and the processes after step 1 are repeated.

  Thus, according to the first embodiment, whether or not to perform manual regeneration is determined from the frequency of automatic regeneration by the process of step 3. For this reason, for example, the exhaust temperature T does not rise sufficiently during a light load operation or in a low rotation state (standby), so the automatic regeneration is completed by the processing in step 5 and the automatic regeneration is repeated in a short time. If the tendency is to be performed (the frequency increases), the process proceeds to step 8 by the process of step 3 to notify the operator to manually perform the regeneration.

  In this case, the manual regeneration based on the operator's operation is regeneration performed with the consciousness (intention) of performing the operator's regeneration. Therefore, for example, the exhaust gas temperature T is sufficiently increased by increasing the rotational speed N of the engine 10. It can be done after raising it. As a result, as shown by the solid characteristic line 33 in FIG. 6, the particulate matter collected by the filter 21 can be sufficiently burned and removed, and the regeneration is prevented from being repeated repeatedly in a short time. can do. As a result, it is possible to reduce fuel consumption (low fuel consumption), suppress excessive accumulation, and suppress dilution of engine oil (oil dilution) due to fuel being mixed into engine oil. As a result, the stability and reliability of the excavator 1 can be improved.

  According to the first embodiment, by the process of step 3, the automatic reproduction interval A is within the reference time α and the automatic reproduction number B performed at the interval within the reference time α is the number threshold β When it becomes above, it is set as the structure which alert | reports so that it may reproduce | regenerate manually with respect to an operator by the process of step 12. FIG. For this reason, it can be determined stably based on the automatic reproduction interval A and the frequency B that the automatic reproduction tends to be repeated. Thus, when manual regeneration is to be performed (when manual regeneration is necessary), the operator can be surely notified.

  According to the first embodiment, after the automatic regeneration is started by the processing of step 5, the automatic regeneration is terminated when the exhaust temperature T becomes lower than the exhaust temperature threshold Tt. For this reason, when the exhaust temperature T is low and sufficient combustion of the particulate matter cannot be expected, the increase in fuel consumption and oil dilution can be suppressed by terminating the automatic regeneration. On the other hand, even if the interval until the next automatic regeneration is shortened by ending the automatic regeneration, the operator is informed to perform the regeneration manually by the processing of step 3 and the subsequent step 12, and the step At 14, manual regeneration is performed. For this reason, it is possible to suppress both the automatic regeneration being continued while the exhaust temperature T is low and the repeated automatic regeneration. Thereby, reduction of fuel consumption (low fuel consumption), suppression of excessive deposition, and suppression of oil dilution can be achieved at a high level.

  According to the first embodiment, the automatic regeneration and the manual regeneration are performed by the processing of Step 7 and Step 16 by the estimated collection amount H (the first estimated collection amount H1 and / or the second estimated collection amount). The reproduction is terminated when H2) becomes equal to or less than the reproduction end threshold value He. For this reason, by setting the regeneration end threshold value He small, the amount of particulate matter (residual amount) of the filter 21 immediately after regeneration can be reduced, and the interval until the next regeneration can be lengthened. On the other hand, if the regeneration end threshold value He is set to a small value, it takes a long time to reach the regeneration end threshold value He or less when the particulate matter does not burn sufficiently due to the low exhaust temperature T during automatic regeneration. There is a possibility that the reproduction end threshold value He will not be reached.

  Even in this case, since the automatic regeneration ends when the exhaust gas temperature T becomes lower than the exhaust gas temperature threshold value Tt, it is possible to prevent the automatic regeneration from continuing while the exhaust gas temperature T is low. In this case, since the automatic reproduction is finished before the reproduction end threshold value He becomes less than or equal to, the interval until the next automatic reproduction is shortened. If this interval is shortened, if it continues, step 3 and the subsequent steps are continued. Through the processing in step 12, the operator is notified to perform manual regeneration, and in step 14, manual regeneration is performed. For this reason, it is possible to prevent the automatic regeneration from being continued and the automatic regeneration from being repeatedly performed while ensuring that the interval until the next regeneration is increased, while the exhaust temperature T is low.

  In the first embodiment, a specific example of the PM calculation means in which the processing in step 1, step 6 in FIG. 4 and step 15 in FIG. 5 is a component of the present invention is shown, and step 2 in FIG. Accordingly, the processing of step 5 and step 7) shows a specific example of the automatic regeneration determination means. Furthermore, a specific example of the manual regeneration determination means in which the processing of step 3 (step 16 if necessary) in FIG. 4 is a constituent requirement of the present invention is shown.

  Next, FIG. 7 shows a second embodiment of the present invention. The feature of the second embodiment is that the automatic regeneration is not performed by post-injection, but the flow path of at least one of the intake throttle valve provided on the intake side of the engine and the exhaust throttle valve provided on the exhaust side. In this configuration, driving is performed in the direction of narrowing down. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In the figure, reference numeral 41 denotes a regenerator that regenerates the filter 21 by burning the particulate matter collected by the filter 21. The regeneration device 41 includes a fuel injection device 14, an intake throttle valve 42, an exhaust throttle valve 43, a rotation sensor 23, pressure sensors 24 and 25, an exhaust temperature sensor 26, a notification device 27, a manual regeneration switch 28, and a controller 29. Has been. When automatic regeneration is performed by the regenerator 41, the particulate matter accumulated on the filter 21 is driven by driving in the direction of restricting the flow path of at least one of the intake throttle valve 42 and the exhaust throttle valve 43. Remove by burning. On the other hand, when manual regeneration is performed, a notification sound or the like from the notification device 27 is received, and post injection is performed manually by the fuel injection device 14 by an operator, and particulate matter deposited on the filter 21 is burned and removed.

  The intake throttle valve 42 is provided on the intake pipe 11 side of the engine 10, and the intake throttle valve 42 constitutes a regeneration device 41 that regenerates the filter 21. Here, the intake throttle valve 42 is held in a normally opened state (for example, an opening corresponding to the fuel injection amount F or a fully opened state) by a control signal from the controller 29. On the other hand, when performing automatic regeneration, the intake throttle valve 42 is driven in a direction to throttle the flow path by a control signal from the controller 29.

  Thus, the intake throttle valve 42 throttles the intake air amount so that the air-fuel ratio of air and fuel tends to be rich. At this time, in the combustion chamber of the engine 10, the temperature of the exhaust gas discharged to the exhaust pipe 12 rises by burning the fuel whose air-fuel ratio tends to be rich, and the particulate matter collected by the filter 21 Can be burned and removed.

  The exhaust throttle valve 43 is provided on the exhaust pipe 12 side of the engine 10, and the exhaust throttle valve 43 also constitutes a regeneration device 41 that regenerates the filter 21. Here, the exhaust throttle valve 43 is held in a fully open state in a normal state by a control signal from the controller 29. On the other hand, when performing automatic regeneration, the exhaust throttle valve 43 is driven in the direction of narrowing the flow path by the control signal from the controller 29, and the opening degree is controlled to be small.

  As a result, the exhaust throttle valve 43 throttles the flow rate of the exhaust gas flowing through the exhaust pipe 12 to apply a back pressure to the engine 10 and increases the load on the engine 10. At this time, the controller 29 increases the fuel injection amount F by the fuel injection device 14 of the engine 10 corresponding to the load. As a result, the temperature of the exhaust gas rises, and the particulate matter collected by the filter 21 can be burned and removed.

  In the second embodiment, automatic regeneration is performed by driving in a direction to throttle the flow path of at least one of the intake throttle valve 42 and the exhaust throttle valve 43 as described above. Regarding the operation, there is no particular difference from that according to the first embodiment described above.

  In particular, in the case of the second embodiment, since automatic regeneration is performed by driving in a direction in which the flow path of at least one of the intake throttle valve 42 and the exhaust throttle valve 43 is throttled, automatic regeneration is performed. Compared with the case of performing by post injection, it can be performed at a low temperature. Thereby, durability of the filter 21 can be improved.

  In each of the above-described embodiments, the automatic reproduction interval A is within the reference time α and the automatic reproduction number B performed at the interval within the reference time α is set to the number threshold β by the processing of step 3. As described above, an example has been described in which the processing in step 12 informs the operator to perform manual regeneration when the above is reached. However, the present invention is not limited to this. For example, as in the modification shown in FIG. 8, the number B of automatic reproduction is equal to or greater than a predetermined number (number threshold δ) set in advance within a preset number measurement time γ. When it becomes, it is good also as a structure which alert | reports to an operator so that it may reproduce | regenerate manually. That is, step 3 in FIG. 4 may be configured to determine whether or not the number of times B of automatic reproduction has reached the number threshold δ (B ≧ δ) within the number measurement time γ.

  In this case, it can be stably determined that the automatic reproduction tends to be repeated based on the number B of automatic reproduction within the number measurement time γ. Thus, when manual regeneration is to be performed (when manual regeneration is necessary), the operator can be surely notified. The number of times measurement time γ and the number of times threshold δ are appropriately set so that the automatic regeneration is repeatedly performed without the exhaust temperature T sufficiently rising by continuing the light load work or the low rotation state standby (leaving). The value is set in advance based on experiments, calculations, simulations, etc. so that the determination can be made.

  In each of the above-described embodiments, the first estimated collection amount H1 is described as an example in which the first estimated collection amount H1 is estimated based on the engine speed N, the fuel injection amount F, and the exhaust temperature (exhaust gas temperature) T. explained. However, the present invention is not limited to this. For example, the first estimated collection amount H1 is determined not only by the engine speed N, the fuel injection amount F, and the exhaust temperature T, but also by the temperature of each part such as a filter, It is good also as a structure performed using combining state quantities (state quantity showing an operation state) etc., etc., etc. together.

  In each of the above-described embodiments, the case where the exhaust gas purification device 18 is configured by the oxidation catalyst 20 and the filter 21 has been described as an example. However, the present invention is not limited to this. For example, in addition to the oxidation catalyst and the particulate matter removal filter, a urea injection valve, a selective reduction catalyst device, and the like may be used in combination.

  Further, in each of the above-described embodiments, the case where the exhaust gas purifying device 18 is mounted on the small hydraulic excavator 1 has been described as an example. However, the construction machine provided with the exhaust gas purifying apparatus according to the present invention is not limited to this, and may be applied to, for example, a medium-sized or larger hydraulic excavator. Further, the present invention can be widely applied to construction machines such as a hydraulic excavator, a wheel loader, a forklift, and a hydraulic crane having a wheel type lower traveling body.

1 Excavator (construction machine)
2 Lower traveling body (car body)
4 Upper swing body (car body)
DESCRIPTION OF SYMBOLS 10 Engine 18 Exhaust-gas purification apparatus 21 Filter 22, 41 Regeneration apparatus 26 Exhaust temperature sensor 27 Notification device 28 Manual regeneration switch 29 Controller

Claims (5)

A vehicle body on which an operator is boarded, an engine mounted on the vehicle body, and an exhaust gas purification device provided on the exhaust side of the engine having a filter that collects particulate matter in exhaust gas discharged from the engine A construction machine comprising a regeneration device for regenerating the filter by burning particulate matter collected by the filter of the exhaust gas purification device,
The playback device
PM calculation means for estimating the amount of particulate matter collected by the filter;
Automatic regeneration determination means for determining whether to automatically regenerate the filter using the estimated collection amount estimated by the PM calculating means;
A manual regeneration determining unit that determines whether to notify the operator to perform manual regeneration based on the frequency of automatic regeneration performed based on the determination of the automatic regeneration determining unit is provided. And construction machinery.   The manual regeneration determination unit is configured such that an automatic regeneration interval performed based on the determination of the automatic regeneration determination unit is within a preset reference time, and the number of times performed at an interval within the reference time is a preset predetermined time. The construction machine according to claim 1, wherein the construction machine is configured to notify the operator to manually regenerate when the number of times is exceeded.   The manual regeneration determination unit is configured to manually operate the operator when the number of automatic regenerations performed based on the determination of the automatic regeneration determination unit becomes equal to or greater than a predetermined number within a preset number measurement time. The construction machine according to claim 1, wherein the construction machine is configured to make a notification so as to perform regeneration.   4. The construction machine according to claim 1, wherein the automatic regeneration determination unit is configured to terminate automatic regeneration when an exhaust gas temperature becomes lower than a predetermined temperature after starting automatic regeneration.   The automatic regeneration determination unit and the manual regeneration determination unit are configured to terminate the regeneration when the estimated collection amount estimated by the PM calculation unit is equal to or less than a preset regeneration end threshold. Or the construction machine of 4.

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