JP7708591B2 - Work vehicles - Google Patents

Description

The present invention relates to agricultural work vehicles such as tractors and riding rice transplanters, and more specifically to work vehicles that use a diesel particulate filter as an exhaust gas aftertreatment device for the diesel engine installed on them.

Diesel engines are primarily used for the engines that drive various parts of agricultural work vehicles, as they have excellent combustion efficiency, good fuel economy, and are powerful even at low revolutions. However, diesel engines have been problematic due to the harmful particulate matter (PM) and nitrogen oxides (NOx) contained in their exhaust gases, and these issues are currently being addressed through improvements to engine combustion technology such as common rail fuel injection systems and exhaust gas recirculation systems (EGR), as well as the adoption of exhaust gas aftertreatment devices such as diesel particulate filters (DPFs) and urea SCR.

The diesel particulate filter, an exhaust gas aftertreatment device mentioned above, captures particulate matter in the exhaust gas (mainly fine particles of solid carbon: soot) on the filter, preventing it from being emitted into the atmosphere. However, as the amount of trapped particulate matter that accumulates increases, it clogs the filter, and so when a certain amount of particulate matter has accumulated, the filter must be regenerated by burning it again at high temperatures to remove it.

If the filter regeneration is performed automatically or appropriately based on manual commands according to the working conditions of the work vehicle, the performance of the diesel particulate filter itself is unlikely to deteriorate. However, if the regeneration process is not performed appropriately and in the right amount according to the amount of accumulated soot, the large amount of accumulated soot will be rapidly combusted during the regeneration process, and there is a risk that the diesel particulate filter itself will be thermally destroyed. It is necessary to take appropriate measures, keeping in mind that this will require expensive filter replacement work.

In order to obtain information regarding the regeneration of the diesel particulate filter while operating a work vehicle while sitting in the driver's seat and to reliably issue a regeneration command in response to the request, it is known that, for example, in a tractor, a DPF regeneration switch is provided on the top surface of the steering column at the base of the steering wheel, and the DPF regeneration switch is positioned within the operator's field of vision when in a straight-ahead working position (see Patent Document 1).

It is also known that wheel loaders and hydraulic excavators are equipped with a regeneration control device having a regeneration means for regenerating a filter, a regeneration start instruction means for instructing the start of operation of the regeneration means, a regeneration prohibition instruction means for instructing the prohibition of operation of the regeneration means, an automatic regeneration control function for activating the regeneration means when the accumulation amount estimated by the accumulation amount estimation means becomes greater than a predetermined first threshold, a manual regeneration control function for outputting a warning signal to prompt the operation of the regeneration start instruction means when the accumulation amount estimated by the accumulation amount estimation means becomes greater than a predetermined second threshold, and activating the regeneration means when the regeneration start instruction means is operated, and a regeneration prohibition control function for prohibiting operation of the regeneration means when the regeneration prohibition instruction means is operated (see Patent Document 2).

In a tractor having a bonnet with an engine mounted at the front of a body with front and rear wheels, and a cabin with a driving operation section consisting of a steering wheel and an instrument panel box with a fuel gauge and other items on its panel surface, a windshield wiper drive mechanism covered by an auxiliary operation box is arranged between the instrument panel box's panel surface, which is inclined forward and backward, and the windshield in front of it, so as to fit at least within the left-right width of the instrument panel box, and a rotating drive shaft extending forward from the wiper drive mechanism is projected outside the vehicle through the front windshield to drive the windshield wipers (see Patent Document 3).

JP 2016-78600 A JP 2011-37334 A Patent No. 3657249

As mentioned above, if a diesel particulate filter is installed as an exhaust gas aftertreatment device on a diesel engine mounted on a work vehicle such as a tractor, harmful particulate matter in the exhaust gas can be captured on the filter and prevented from being emitted directly into the atmosphere. However, if the engine is operated for a long period of time, depending on the work content and working environment, a large amount of particulate matter can accumulate on the filter, and if left unchecked, this can lead to the filter becoming clogged.

To prevent this, the engine's electronic control unit, for example, estimates the amount of soot accumulated in the filter, and if the amount of soot accumulates above a certain percentage, performs automatic regeneration to burn and remove the soot without restricting engine output (without interfering with normal operation). Furthermore, if the soot combustion does not progress even after automatic regeneration and the percentage of soot accumulation increases further, a manual regeneration request is made using a lamp, buzzer, etc.

When the worker receives a notification of a manual regeneration request from the engine's electronic control device, moves the work vehicle to a place where there is no risk of fire, parks it, and then issues the command using the manual regeneration switch, the engine's electronic control device limits the engine's rotation speed and re-burns the fuel at a high temperature to burn and remove the soot that has accumulated on the filter. Note that there is a risk of fire if the above-mentioned automatic regeneration is performed indoors with poor ventilation or in places close to flammable materials (such as in the shade of a tree or in a vinyl greenhouse), so in such cases, a switch is provided to issue a command to prohibit automatic regeneration and a lamp is provided to indicate this state.

Therefore, in consideration of the risk of the filter becoming clogged or broken, notifications from the engine's electronic control device regarding the regeneration of the diesel particulate filter must be conveyed to the operator promptly, and the operator's commands to perform manual regeneration or to prohibit automatic regeneration must be given appropriately. However, when an operator is sitting in the driver's seat and driving a work vehicle, the operator uses the steering wheel to steer the vehicle while looking through the bonnet that covers the engine at the road surface and field scene ahead, or at ridges and obstacles on the road. Therefore, if the DPF regeneration switch is positioned below the steering wheel, as in Patent Document 1 mentioned above, there is a risk that the operator will overlook a manual regeneration request from the engine, even if he or she can operate the regeneration switch.

In addition, the DPF regeneration switch located on the top surface of the steering column is close to the driver's seat, and it is conceivable that an inexperienced operator may inadvertently operate the DPF regeneration switch or touch it by mistake, so there is no obvious advantage to installing it on the top surface of the steering column at such a cost. There is also empty space above the front of the dashboard where the operation display panel in front of the steering wheel is located. Patent Document 3 also suggests that an operation box for auxiliary equipment could be installed in this space, allowing the auxiliary equipment to be operated safely and easily without taking one's eyes off the ground while the aircraft is moving.

In view of the problem with the placement of the DPF regeneration switch described in Patent Document 1, and based on the suggestion of effective use of free space described in Patent Document 3, the present invention aims to provide a work vehicle that, particularly when a diesel particulate filter is used as the exhaust gas aftertreatment device of the diesel engine, places the switch and lamp related to the regeneration of the filter in an optimal location, and can reliably notify the worker based on the lamp while ensuring the operability of the switch.

In order to solve the above problems, the present invention provides a work vehicle in which a panel cover is provided in front of the driver's seat on which a steering wheel, meter panel, and various operating switches are attached, and a diesel engine is provided in front of these and covered by a bonnet. The diesel engine is equipped with an exhaust gas purification device that collects particulate matter in the exhaust gas with a diesel particulate filter and regenerates the filter by burning and removing the collected particulate matter, while switches and lamps related to the regeneration of the filter are provided on the rear surface of a sub-panel cover provided near the center above the front of the panel cover, so that the switches and lamps provided on the meter panel of the panel cover and the sub-panel cover are within the forward field of view of the worker sitting in the driver's seat.

The present invention is also characterized in that a DPF regeneration lamp and an engine failure lamp are provided on the meter panel attached to the panel cover, and a manual regeneration switch, a regeneration inhibition switch, and lamps for each switch are provided on the rear surface of the sub-panel cover.

The present invention is further characterized in that a storage section for a mobile terminal is formed near the center of the rear surface of the sub-panel cover, and a manual regeneration switch with a lamp and a regeneration inhibition switch, as well as a power socket for charging the mobile terminal, are provided on the left and right sides of the rear surface of the sub-panel cover.

The present invention is characterized in that an electronic control unit that acquires engine information and filter regeneration information and controls the illumination of lamps provided on the meter panel of the panel cover or the sub-panel cover, or an electric motor that drives the wipers provided on the windshield of the cabin, or these electronic control units and electric motors are provided below the sub-panel cover and covered by the sub-panel cover.

The work vehicle of the present invention has a panel cover in front of the driver's seat on which a steering wheel, meter panel, and various operating switches are attached, and a diesel engine is installed in front of these and covered by a bonnet. The diesel engine is equipped with an exhaust gas purification device that collects particulate matter in the exhaust gas with a diesel particulate filter and regenerates the filter by burning and removing the collected particulate matter, while switches and lamps related to the regeneration of the filter are provided on the rear surface of a sub-panel cover provided near the center above the front of the panel cover, so that the meter panel of the panel cover and the switches and lamps provided on the sub-panel cover are within the forward field of view of the worker sitting in the driver's seat.

Therefore, when an operator is sitting in the driver's seat and driving a work vehicle, the operator uses the steering wheel to steer while looking through the bonnet that covers the engine at the road surface and field scene ahead, as well as ridges and obstacles on the road. In this case, the switches and lamps on the meter panel and sub-panel cover of the panel cover are within the operator's forward field of vision, so that the operator can quickly receive warnings regarding the regeneration of the diesel particulate filter without overlooking them and can take appropriate action.

The switch for regenerating the filter is located on the rear of the sub-panel cover, slightly forward of the steering wheel, so there is little risk of it being touched by mistake while holding the steering wheel or being operated carelessly by an inexperienced operator. On the other hand, when operating the switch, the driver can reach it by standing up from the driver's seat and reaching forward, and by turning this switch on, the driver can reliably command manual filter regeneration, etc., after which the driver can get off the vehicle and wait for regeneration to be completed.

Moreover, when replacing an engine with one that is equipped with a diesel particulate filter, the work vehicle will need to have new regeneration switches installed in the steering section, etc., but forcing these switches onto the steering column, for example, can lead to increased machining costs and increased costs. Also, there is usually no extra space available to install new switches or lamps on panel covers that house meter panels and various operating switches.

However, there is originally an open space above the panel cover, and the rear part of the panel cover serves as a visor for the meter panel, which is somewhat elevated, but the part in front of that slopes downward and is lower. Therefore, even if a sub-panel cover is provided near the center of the upper front part, there is no risk of the sub-panel cover blocking or impairing forward visibility. Furthermore, if switches and lamps related to filter regeneration are provided on the rear surface of the sub-panel cover, these switches and lamps will be recognized as being separate from the switches and the like provided on the panel cover, which can increase the level of attention drawn by the alarm.

In addition, according to the work vehicle of the present invention, a DPF regeneration lamp and an engine failure lamp are provided on the meter panel provided on the panel cover, and a manual regeneration switch, a regeneration prohibition switch, and the lamps for each switch are provided on the rear surface of the sub-panel cover. Therefore, detailed information regarding filter regeneration can be accurately notified using the DPF regeneration lamp, engine failure lamp, manual regeneration switch, and regeneration prohibition switch lamps that are within the forward field of vision of the worker.

In more detail, for example, when a request for manual filter regeneration is made, the DPF regeneration lamp on the meter panel and the manual regeneration switch lamp on the rear surface of the sub-panel cover can be made to flash simultaneously to warn the user to issue a command for manual regeneration immediately, and when automatic or manual regeneration is performed, the DPF regeneration lamp and the manual regeneration switch lamp can be turned on to notify the user, or when an over-accumulation request is made, the DPF regeneration lamp can be made to flash but the manual regeneration switch lamp can be turned off, and the engine failure lamp can be turned on to notify the user that manual regeneration is not possible.

Furthermore, according to the work vehicle of the present invention, a storage section for a mobile terminal is formed near the center of the rear surface of the sub-panel cover, and a manual regeneration switch with a lamp and a regeneration inhibition switch, as well as a power socket for charging the mobile terminal, are provided on the left and right sides of the rear surface of the sub-panel cover.

Therefore, not only can the sub-panel cover, which is equipped with playback switches and lamps, be effectively used as a place to store smartphones and mobile phones, but the mobile terminal placed in the housing of this sub-panel cover is within the worker's forward field of vision along with the switches and lamps, as mentioned above, so incoming calls and e-mails can be prevented from being overlooked. In addition, by connecting the mobile terminal to the power socket via a charger or the like, the mobile terminal can be charged while working, increasing convenience.

The work vehicle of the present invention has an electronic control unit that acquires engine information and filter regeneration information and controls the illumination of lamps on the meter panel and sub-panel cover of the panel cover, or an electric motor that drives the wipers on the windshield of the cabin, or these electronic control units and electric motors are provided below the sub-panel cover and covered by the sub-panel cover.

Therefore, even if a new lamp related to diesel particulate filter regeneration is installed and an electronic control unit is required to control the illumination of this lamp, this electronic control unit can be installed under the sub-panel cover close to the lamp and engine, and the sub-panel cover itself can cover the electronic control unit without exposing it to wind and rain, without the need for a separate cover.

In addition, in a work vehicle equipped with a cabin that covers the control section, the electric motor that drives the wipers on the windshield of the cabin is installed below the panel cover, and in order to cover this electric motor with the panel cover, the front part of the panel cover is bulged out and prepared as a separate part from the panel cover without the cabin. However, if such an electric motor is installed below the sub-panel cover and covered by the sub-panel cover, there is no need to bulge out the front part of the panel cover, so the panel cover with the cabin specification can be eliminated, thereby reducing costs in terms of parts management.

FIG. FIG. 2 is a side view of the drive unit and the steering unit. FIG. This is a front view of the control panel as seen from the driver's seat side. FIG. 2 is a side view of the control section mainly composed of the sub-panel cover. FIG. 13 is a perspective view illustrating the attachment of the sub-panel cover, as viewed obliquely from the rear side. FIG. 11 is a perspective view illustrating the attachment of the sub-panel cover, as viewed obliquely from the front side. FIG. 1A is a perspective view of a sub-panel cover, FIG. 1B is a plan view, FIG. 1C is a front view, and FIG. FIG. 13 is a perspective view of a switch for regenerating a filter. FIG. 13 is an explanatory diagram of a switch label and a connector. FIG. 4 is a side view showing the mounting state of a wiper motor provided in a cabin. FIG. 2 is an explanatory diagram of a main part of a tachometer and lamps provided on a meter panel.

An embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 to 5, an agricultural tractor 1 as a work vehicle has an engine 2 and front and rear transmission cases 3, 4 connected together to form a vehicle body (machine body). A front axle case (not shown) is supported on the underside of a chassis bracket 5 that is fixed to the left and right near the bottom of the engine 2 and extends forward, allowing it to swing left and right. Front axle cases are attached to the left and right ends of this front axle case, respectively, and each front axle case supports a front axle 6, and left and right front wheels 7 attached to this front axle 6 are provided so that they can be steered.

Meanwhile, rear axle cases fixed to the left and right sides of the rear transmission case 4 support rear axles 8, with left and right rear wheels 9 attached to each rear axle 8. A well-known three-point link mechanism consisting of a top link 10 and left and right lower links 11 is provided at the rear of the vehicle body. This three-point link mechanism is used to connect a work machine such as a rotary tiller, and the work machine is attached to the top of the rear transmission case 4 and can be raised and lowered freely via left and right lift arms of a cylinder case with lifting cylinders inside, and lift rods whose ends are connected to the tips of each lift arm and the middle of the lower link 11.

Furthermore, the aforementioned engine 2 is a diesel engine, and in response to stricter exhaust gas regulations, this engine 2 employs a common rail fuel injection system, turbocharger, exhaust gas recirculation system (EGR), and other systems to reduce the generation of particulate matter such as nitrogen oxides generated by complete combustion and soot generated by incomplete combustion. In addition, nitrogen oxides and particulate matter that cannot be purified by the engine itself are removed using a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) as exhaust gas aftertreatment devices.

For this reason, the diesel engine 2 is provided with a DPF case 12, which houses a DOC and a DPF, attached to the upper rear part of the main body. Gas exhausted from the engine 2 is introduced into the DPF case 12, and then discharged outside the aircraft from a tail pipe (not shown) provided on the outlet side of the DPF case 12. An accessory bracket 13 consisting of a bottom plate and stays is attached to the upper surface of the chassis bracket 5 mentioned above, and this accessory bracket 13 is provided with a radiator 14 that cools the cooling water for the engine 2, an air cleaner 15 that supplies clean air to the engine 2, an oil cooler 16, an intercooler 17, a battery 18, etc.

The engine 2 and accessories are covered by a bonnet 19 that has air vents 19a and headlamps 20 on the front. The bonnet 19 is attached to the top of a cover bracket 21 attached to the rear of the engine 2 via a hinge, and the front part of the bonnet can be opened and closed freely. The outer periphery of the cover bracket 21 is covered by an inverted U-shaped rear cover 22, and left and right side covers 23 are attached to the accessory bracket 134 below the rear cover 22 using knobbed bolts so that they can be attached and detached freely.

Furthermore, a steering section is provided behind the rear cover 22, and this steering section is composed of a floor frame 25 that is supported on the transmission cases 3 and 4 in an anti-vibration manner and has the driver's seat 24 located in the center near the rear, left and right fenders 26 that cover the front and upper parts of the rear wheels 9, and a safety frame 27 located behind the driver's seat 24. Of these, an inverted U-shaped handle frame 28 is erected in front of the floor frame 25 facing the rear cover 22 on the engine side, and a steering handle 29 that steers the left and right front wheels 7 by a fully hydraulic power steering unit is attached to a column mounting bracket 28a located near the top of this handle frame 28 so that the tilt can be freely adjusted.

In addition, below the steering handle 29 are provided a combination switch 30, a quick-up lever 31 for raising and lowering the work machine, an engine control lever 32, and a forward/reverse lever 33, and the steering shaft 34 and steering column 35 are entirely covered by a cover 36. Furthermore, on the column mounting bracket 28a, a main clutch pedal 37 is provided on the left side as viewed from the driver's seat 24, and left and right brake pedals 38 are provided hanging down on the right side, and a parking brake lever 39 is provided near the center.

The column mounting bracket 28a in front of the steering wheel 29 is provided with a cover that covers it, and this cover is composed of a panel cover 40 provided near the top and a rear panel cover 41 that covers the rear surface near the bottom. In addition, an opening 40a provided on the rear surface near the center of the top of the panel cover 40 is fitted with a meter panel 42 with glass 42b on the front of a case 42a, so that when an operator sits in the driver's seat 24 and looks forward, the meter panel 42 can be seen between the rim and hub of the steering wheel 29, and the surface of the meter panel 42 is tilted toward the panel cover 40 so that it is approximately perpendicular to the operator's line of sight (see Figures 6 and 7).

The peripheral portion of the opening 40a of the panel cover 40 where the meter panel 42 is attached is formed into a visor (sunshade) 40b that rises backward, and the upper surface of the meter panel 42 near the center as a whole is inclined downward toward the front. Also, behind the opening 40a where the meter panel 42 is attached, there are provided on the left and right sides of the opening 40c where the cover 36 of the steering wheel 29 fits, a left front unit 43 equipped with switches for turning on and off various automatic controls (double speed, backup, turning up, etc.) and LEDs that display the on/off state, and a right front unit 45 equipped with operation switches for setting the display screen of the liquid crystal display 44 equipped on the meter panel 42.

Furthermore, a hazard lamp switch 46 and a horn switch 47 are provided on the panel cover 40 above and below the left front unit 43, and a starter switch 48 is provided on the panel cover 40 below the right front unit 45. In addition to the switches and control levers described above, the tractor 1 also has controls such as a travel and PTO gear shift lever and pedals, a position lever for raising and lowering the work equipment, various switches, and volumes, distributed in appropriate locations on the panels provided on the left and right sides of the driver's seat 24 and on the floor surface of the floor frame 25.

The outline of the tractor 1 has been explained above, and next we will explain the regeneration of the diesel particulate filter equipped in the diesel engine 2 and the installation of the switches and lamps related to this regeneration. First, as mentioned above, the diesel particulate filter collects soot contained in the exhaust gas of the diesel engine 2. In addition, the electronic control device (electronic control unit: ECU) that controls the diesel engine 2 estimates the amount of soot accumulated in the diesel particulate filter (accumulation amount ratio) based on an exhaust temperature sensor, an exhaust pressure differential sensor, etc.

The ECU of the engine 2 treats the engine 2 as operating normally if the soot accumulation rate (percentage) is, for example, between 0 and less than 80, and issues an automatic regeneration request if it is 80 or more. Here, if an automatic regeneration request is issued and the engine speed is high and the cooling water temperature is high, the common rail fuel injection system mixes unburned fuel into the exhaust pipe by post injection, and the diesel oxidation catalyst oxidizes and burns this unburned fuel, raising the temperature of the exhaust gas passing through the diesel particulate filter, so that the soot accumulated on the diesel particulate filter can be re-burned and removed from the filter.

Furthermore, the ECU of engine 2 issues a manual regeneration request if the soot accumulation ratio is 100 or more, regardless of the automatic regeneration described above. In this case, if the ratio is between 100 and less than 120 in the early period, engine output is not limited, but if the ratio is between 120 and less than 140 in the later period, engine output is limited to 50 percent and maximum rotation to 1500 rpm. Then, when manual regeneration is commanded by the operator, the main and post injection amounts are increased compared to automatic regeneration, the exhaust temperature is increased, and the regeneration speed of the diesel particulate filter is accelerated.

Furthermore, if the soot accumulation ratio is 140 or more, the ECU of engine 2 issues an over-accumulation request, and in this case, if it is in the early stage where it is between 140 and less than 160, the engine output is limited by first setting the engine output at 50 percent and the rotation limit at 1500 rpm in the first stage, and then setting the rotation limit at 1200 rpm in the second stage 7200 seconds later. Also, if it is in the later stage where it is 160 or more, the first stage also sets the engine output at 50 percent and the rotation limit at 1500 rpm, and then setting the rotation limit at 1200 rpm in the second stage 3600 seconds later.

When the engine 2 ECU regenerates the diesel particulate filter, the exhaust gas and tailpipe become hot, and there is a risk of fire or gas poisoning if the automatic regeneration is performed indoors with poor ventilation or in a place close to flammable materials (such as in the shade of a tree or a vinyl greenhouse), so in such cases the operator can issue a command to prohibit automatic regeneration. Also, when issuing a command for manual regeneration, the tractor 1 must be moved to a safe, wide, well-ventilated outdoor location with no flammable objects nearby, and the engine 2 must be put into an idling state before manual regeneration can be performed.

Furthermore, if automatic or manual regeneration of the diesel particulate filter cannot be performed properly and the above-mentioned excessive deposition request is issued, the worker will not be able to regenerate the diesel particulate filter himself, so he must stop the work immediately and leave it to a service technician to attempt regeneration using a service tool, or in the worst case scenario, repair or replace the diesel particulate filter.

The tractor 1 is provided with a DPF regeneration lamp 49 and an engine failure lamp 50 that notify the status of the DPF (request/regeneration/abnormal) on the meter panel 42 of the panel cover 40 for regeneration as described above, as shown in FIG. 4. In addition, the tractor 1 is provided with a manual regeneration switch that issues a command for manual regeneration, a regeneration prohibition switch that issues a command for prohibiting regeneration, as well as a manual regeneration lamp that notifies the request and execution of manual regeneration, and a regeneration prohibition lamp that notifies the execution of a regeneration prohibition.

The above-mentioned manual regeneration switch and manual regeneration lamp, and the regeneration prohibition switch and regeneration prohibition lamp each use a push button switch with an LED bulb that integrates the lamp and switch, and these two manual regeneration switches (with lamp) 51 and regeneration prohibition switch (with lamp) 52 are attached to the rear surface 53a of a synthetic resin sub-panel cover 53. The sub-panel cover 53 is attached to the upper front center of the panel cover 40, so that the switches and lamps on the meter panel 42 of the panel cover 40 and the sub-panel cover 53 are within the forward field of view of the operator sitting in the driver's seat 24.

To explain in more detail, as shown in Figures 6 to 10, an opening 40d is provided near the center of the upper front part of the panel cover 40, and the front mounting seat 28b fixed to the handle frame 28 is raised upward through this opening 40d, and the rear mounting seat 28c is attached to the rear edge of the opening 40d and raised upward, and a cushioning material 54 is attached to the rear edge of the opening 40d to prevent water and dust from entering the panel cover 40. On the other hand, the sub-panel cover 53, which is formed in a lid shape so that the inside becomes a storage space for the switch, has ribs 53b at four locations on the front, back, left and right of its inner surface, and the lower ends of the legs of a four-pronged reinforcing metal fitting 55 are fixed to this rib 53b with clips 56, and the reinforcing metal fittings 55 prevent the side walls 53c of the sub-panel cover 53 from deforming in the left and right direction.

Then, the sub-panel cover 53 with the reinforcing metal fittings 55 attached is placed from above to cover the opening 40d of the panel cover 40, and the sub-panel cover 53 and the reinforcing metal fittings 55 are fixed to the front mounting seat 28b and the rear mounting seat 28c with screws 57. Therefore, the sub-panel cover 53 fits snugly over the upper front center upper surface of the panel cover 40, and although both covers 40, 53 are individually molded from synthetic resin, when both are attached to the handle frame 28, they present an appearance that can be regarded as if they were a single, integrated cover.

The sub-panel cover 53 covers the opening 40d of the panel cover 40, and its front part is curved to cover the top of the inverted U-shaped handle frame 28. This is because the bonnet 19 and rear cover 22 are higher to accommodate the enlarged diesel engine 2 equipped with a diesel particulate filter at the front of the vehicle body, creating a gap between them and the top of the handle frame 28, resulting in a step. This gap is then blocked and hidden by the front part 53d that extends forward of the sub-panel cover 53, thereby eliminating the step at the boundary between the bonnet 19 and the steering wheel and improving the aesthetic appearance.

The rear surface 53a of the sub-panel cover 53 on which the manual regeneration switch 51 and regeneration inhibit switch 52 are attached is formed at a slight inclination so that the upper portion is positioned further forward than the lower portion, and the angle of inclination is the same as when the face of the meter panel 42 provided at the rear is approximately perpendicular to the forward line of sight of the operator. A mobile terminal storage section 53g having left and right side walls 53e and a rear wall 53f is integrally formed near the center of the rear surface 53a of the sub-panel cover 53, thereby making effective use of the sub-panel cover 53.

That is, when riding the tractor 1 to drive for work, etc., a smartphone, mobile phone, etc., left in a pocket, etc., can get in the way. Also, it would be convenient to have a place to put these when displaying the route to the field or the trajectory of the drive for work. Therefore, a storage section 53g in which these can be placed is formed in the newly installed sub-panel cover 53, and by inserting a smartphone sideways into this storage section 53g, for example, the smartphone can be placed on the front (top) surface of the panel cover 40 and held there by filling the gaps between the three packing rubbers 58 provided on the rear surface 53a of the sub-panel cover 53, the rear wall 53f of the storage section 53g, and the left and right side walls 53e.

Therefore, regardless of the vibration or tilt of the tractor 1, the smartphone can be prevented from flying out, eliminating damage caused by an unexpected fall. In addition, when a smartphone is stored in the storage section 53g, the screen is perpendicular to the operator's line of sight, similar to the meter panel 42, making it easy to see. Furthermore, the central portion 53h of the rear wall 53f of the storage section 53g is recessed so that the screen is easily visible, allowing the operator to quickly check incoming calls and e-mails without having to take the smartphone out of the storage section 53g each time.

A power socket (cigarette lighter socket) 59 is provided on the rear surface 53a, which is to the right of the storage section 53g of the sub-panel cover 53, and a recess 53i for passing a cable through is formed near the upper front part of the right side wall 53e of the storage section 53g. Therefore, for example, if the cable of a charger plugged into the power socket 59 is inserted into the charging terminal of a smartphone and the cable is passed through the recess 53i and the smartphone is placed in the storage section 53g, there is no risk of the smartphone floating up unstably due to interference between the cable and the right side wall 53e of the storage section 53g, making it impossible to store the smartphone inside, and the smartphone can be securely stored in the storage section 53e for charging.

On the other hand, an anti-theft switch 60 is provided on the rear surface to the right of the power socket 59 provided on the right side of the sub-panel cover 53. This anti-theft device detects the shaking of the tractor 1 and alerts the user with a buzzer. As shown in FIG. 11, the manual regeneration switch 51 and the regeneration prohibition switch 52 are provided side by side on the rear surface 53a on the left side of the sub-panel cover 53. To make it easy to tell at a glance which switch is the manual regeneration switch 51 and which is the regeneration prohibition switch 52, the switch label 61 with the name and mark attached to the sub-panel cover 53 is colored in inverted colors, for example, white (manual regeneration) and black (regeneration prohibition), since white has an image of positive or beginning and black has an image of negative or rejection.

In addition, the connector colors of the wiring between the manual regeneration switch 51 and the regeneration inhibition switch 52 and the ECU of the engine 2 are unified with the color of the switch label 61 described above. For example, the connector 62 on the manual regeneration side is white and the connector 63 on the regeneration inhibition side is black, thereby eliminating incorrect connections and preventing trouble. The lamps of the manual regeneration switch 51 and the regeneration inhibition switch 52 use yellow or orange as their warning colors, and these colors encourage prompt action in the event of an alarm.

The manual regeneration switch 51 provided on the sub-panel cover 53 as described above keeps the lamp off during normal operation when the soot accumulation ratio of the filter is between 0 and less than 80, or during automatic regeneration when the ratio is 80 or more and an automatic regeneration request has been issued, in response to a series of control contents of the engine 2 ECU related to the regeneration of the diesel particulate filter described above. The DPF regeneration lamp 49 on the meter panel 42 is turned off when automatic regeneration is not being performed, and is continuously lit when automatic regeneration is being performed.

Also, when the accumulation ratio is 100 or more and a manual regeneration request is made, if it is in the early period, the lamp of the manual regeneration switch 51 and the DPF regeneration lamp 49 will flash ON: 0.5 seconds, OFF: 0.5 seconds. Furthermore, if it is in the later period, they will flash at a shorter cycle of ON: 0.3 seconds, OFF: 0.3 seconds. The DPF regeneration request buzzer separately installed on the machine will emit two single tones once per minute in this case in the early period, and will emit an intermittent warning sound of ON: 0.3 seconds, OFF: 0.3 seconds in the later period. Then, when the manual regeneration switch 51 is turned on and manual regeneration is performed, both the lamp of the manual regeneration switch 51 and the DPF regeneration lamp 49 will be constantly lit.

When the deposition ratio is 140 or more and an over-deposition request is issued, regardless of whether it is early or late, the lamp of the manual regeneration switch 51 is turned off to notify the user that manual regeneration is no longer possible. However, in this case, the DPF regeneration request buzzer and DPF regeneration lamp 49 continue to sound and flash with a short period of ON: 0.3 seconds, OFF: 0.3 seconds, and the engine failure lamp 50 on the meter panel 42 is constantly lit to prompt the user to stop the operation immediately.

If the DPF becomes abnormally hot while regeneration is in progress, the DPF regeneration lamp 49 will flash rapidly (ON: 0.15 seconds, OFF: 0.15 seconds) and the engine malfunction lamp 50 will also be constantly lit to alert of an emergency. On the other hand, the regeneration prohibition switch 52 provided on the sub-panel cover 53 turns the lamp off when the switch is turned off, and turns the lamp on when the switch is turned on. When the switch is on, a command is sent to the ECU of the engine 2 not to regenerate the diesel particulate filter, so in this case automatic regeneration will not be performed.

The complex and detailed drive control of the manual regeneration switch 51 and regeneration inhibit switch 52 lamps on the sub-panel cover 53, the DPF regeneration lamp 49 and engine failure lamp 50 on the meter panel 42 of the panel cover 40, and the DPF regeneration request buzzer on the aircraft must be performed appropriately, taking into consideration the fact that the warning content is conveyed to the operator in an easy-to-understand manner.

However, the information regarding filter regeneration output from the engine 2 ECU is often only the minimum necessary information, and lamps and the like cannot be driven appropriately based on the signal obtained as is. For this reason, an electronic control unit 64 for converting information from the engine ECU may be interposed between the lamps and the like. For this reason, the tractor 1 is provided with a filter regeneration notification electronic control unit 64 that drives and controls lamps and the like with a unified notification pattern that imitates the filter regeneration warnings of other work vehicles such as combine harvesters, and this electronic control unit 64 is attached to the column mounting bracket 28a and covered by the sub-panel cover 53 (see Figure 6).

When the control section of the tractor 1 is covered with a cabin as shown in FIG. 12, an electric motor (wiper motor) 67 that drives a wiper 66 mounted on the windshield 65 of the cabin is provided below the panel cover 40. In this case, the front part of the panel cover 40 is bulged out to cover this electric motor 67, and a separate part is provided to cover it from the panel cover 40 that does not bulge out for cabin-less models.

However, even if the electric motor 67 is attached to the column mounting bracket 28a in the conventional manner, the electric motor 67 is located below the sub-panel cover 53 and can be covered by the sub-panel cover 53 as is, so the cabin-style panel cover 40 with a bulging front is not necessary, and by eliminating this part, costs in parts management can be reduced.

In addition, when manually regenerating the filter as described above, the tractor 1 must be moved to a safe, open, well-ventilated location outdoors where there are no flammable objects nearby, and the parking brake must be applied to stop the vehicle, before the engine 2 ECU can start manual regeneration.

However, as shown in FIG. 13, when the ECU of the engine 2 issues a request for manual regeneration, if the DPF regeneration lamp 49 and the manual regeneration switch 51 lamp on the meter panel 42 are made to flash, and at the same time the parking lamp 68 provided on the meter panel 42 is made to flash, when a manual regeneration command is issued, the flashing of the parking lamp 68 makes it clear that the parking brake lever 39 must be operated to apply the parking brake, preventing forgetting to operate the parking brake lever 39 and enabling a smooth transition to manual regeneration.

When the manual regeneration switch 51 is turned on, even if the tractor 1 is stopped and the parking brake is not applied, the electronic control unit on the tractor 1 side can supply pressure oil to a hydraulic brake cylinder (not shown) to automatically brake the wheels 6, 9 of the tractor 1. This allows the tractor 1 to be kept essentially in a parked state even if the parking brake is forgotten to be operated, and this allows for a quick transition to manual regeneration.

In addition, when the ECU for the engine 2 is performing manual regeneration of the filter, if the engine control lever 32, which commands the engine 2 RPM, or the foot control pedal is operated to command the engine RPM to be higher than idling, the ECU assumes that work is about to begin and suspends manual regeneration of the filter. However, if this RPM command is generated by an operator's erroneous operation or by accidental contact with the engine control lever 32, etc., when getting on or off the tractor 1, the suspension of regeneration will extend the regeneration time, so such suspension of regeneration should be avoided as much as possible.

The electronic control unit of the tractor 1 monitors the engine speed command value from the engine control lever 32 or foot control pedal once a manual regeneration command is issued, and if, for example, the command value temporarily becomes higher than the idling speed but immediately returns to the idling speed, it determines this to be an erroneous operation and continues to provide the idling speed to the ECU of the engine 2, thereby avoiding interruption of filter regeneration. The electronic control unit of the tractor 1 can also similarly avoid interruption of filter regeneration by continuing to provide the idling speed as the engine speed once a manual regeneration command is issued until the regeneration is completed.

Furthermore, when the ECU of the engine 2 starts manual regeneration of the filter, it is difficult to plan when to resume work because it is not known when the filter regeneration will be completed, which causes stress for the worker. Therefore, when manual regeneration of the filter is started, the remaining time for regeneration is displayed using the tachometer 69 provided on the meter panel 42 as shown in FIG. 13. Therefore, by displaying, for example, 10 minutes remaining per 1000 rpm of the tachometer, it is possible to eliminate the need to provide a dedicated display device to display the waiting time.

In addition, the tachometer 69 provided on the meter panel 42 may be configured to be able to be switched between a mode that displays the waiting time until the filter regeneration is completed and a mode that displays the original engine 2 RPM by pressing and holding the manual regeneration switch 51 after the ECU of the engine 2 starts manual regeneration of the filter, and in this way, the control state of the engine RPM during manual regeneration of the filter becomes clear. In the above-described embodiment, the sub-panel cover 53 is formed with a storage section 53g for a mobile terminal, but other items such as cigarettes may be placed in this storage section 53g, and the present invention is not necessarily limited to the above-described embodiment.

1. Tractor (work vehicle)
2 Diesel engine 7 Front wheel 9 Rear wheel 12 DPF case (diesel particulate filter)
19 Hood 24 Driver's seat 29 Steering wheel 40 Panel cover 42 Meter panel 49 DPF regeneration lamp 50 Engine malfunction lamp 51 Manual regeneration switch 52 Regeneration inhibit switch 53 Sub-panel cover

Claims (4)

A work vehicle in which a steering wheel, meter panel, and various operating switches are attached to a panel cover in front of the driver's seat, and a diesel engine is installed in front of these and covered by a bonnet, and the diesel engine is equipped with an exhaust gas purification device that collects particulate matter in the exhaust gas with a diesel particulate filter and regenerates the filter by burning and removing the collected particulate matter, while switches and lamps related to the regeneration of the filter are provided on the rear surface of a sub-panel cover provided near the center of the upper front part of the panel cover, so that the switches and lamps provided on the meter panel of the panel cover and the sub-panel cover are within the forward field of view of the worker sitting in the driver's seat. The work vehicle according to claim 1, characterized in that a DPF regeneration lamp and an engine failure lamp are provided on the meter panel provided on the panel cover, and a manual regeneration switch, a regeneration prohibition switch, and lamps for each switch are provided on the rear surface of the sub-panel cover. The work vehicle according to claim 2, characterized in that a storage section for a mobile terminal is formed near the center of the rear surface of the sub-panel cover, and a manual regeneration switch with a lamp and a regeneration inhibition switch, as well as a power socket for charging the mobile terminal, are provided on the left and right sides of the rear surface of the sub-panel cover. The work vehicle according to claim 3, characterized in that an electronic control unit that acquires engine information and filter regeneration information and controls the illumination of lamps provided on the meter panel and sub-panel cover of the panel cover, or an electric motor that drives a wiper provided on the windshield of the cabin, or these electronic control units and electric motors are provided below the sub-panel cover and covered by the sub-panel cover.