Work vehicles

Abstract

To provide a work vehicle which can prevent appearance from being deteriorated and manufacturing cost from increasing when providing a waste-heat hole on a bonnet etc so as to configure not to impart heat damage to a peripheral component by exhausting, from the waste-heat hole, heat generated by an exhaust gas post-processing device which and an engine are covered with the bonnet.SOLUTION: A work vehicle is configured to cover an exhaust gas post-processing device 16 provided above and in a rear-end approaching part of an engine, with a rear-end approaching part of the bonnet and a front-end approaching part of a spacer cover 37 in front of a heat-shield plate, and comprise the waste-heat holes 37c, 37d in a top plate part and a lateral plate of a spacer cover facing the exhaust gas post-processing device, so as to exhaust hot-air with high temperature raised by the exhaust gas post-processing device from waste-heat holes to outside the work vehicle.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a work vehicle, primarily for agricultural use, such as a tractor or riding rice transplanter, and more particularly to a work vehicle in which an exhaust gas aftertreatment device is covered together with an engine by a hood. [Background technology]

[0002] Diesel engines are the main engines used to power 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 criticized for the harmful particulate matter (PM) and nitrogen oxides (NOx) contained in their exhaust gases, and these issues are now 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.

[0003] Incidentally, the diesel particulate filter, an exhaust gas aftertreatment device mentioned above, traps particulate matter in the exhaust gas (mainly solid carbon particles: soot) on the filter, preventing it from being emitted into the atmosphere. However, as the amount of trapped particulate matter accumulates, it clogs the filter, so once a certain amount has accumulated, the filter must be regenerated by burning it again at high temperatures to remove it.

[0004] When regenerating this filter, the DPF becomes hot and generates heat, which increases the temperature inside the hood that covers the engine and exhaust gas aftertreatment device, potentially exceeding the heat resistance temperature of the engine and DPF components (such as sensors and rubbers).To address this issue, it has been proposed to provide a heat exhaust hole in the top plate of the hood located above the DPF, allowing heat around the DPF to escape through this hole, thereby preventing thermal damage to surrounding components due to the high temperature of the DPF (see Patent Document 1).

[0005] In this case, the strength of the bonnet is improved by a reinforcing member provided below the heat exhaust port, and this reinforcing member is a plate member formed with an approximately U-shaped cross section, which prevents water droplets such as rain that have entered through the heat exhaust port from getting on the DPF, thereby eliminating the risk of impeding filter regeneration, turning into water vapor and impairing forward visibility from the driver's seat, or causing rust on the DPF or surrounding parts.

[0006] In this work vehicle, a partition wall consisting of a heat shield and a spacer cover that covers the outer periphery of the heat shield is installed behind the hood, and by separating the hood from the control section with this partition wall, the habitability of the control section is improved. In other words, the radiator that cools the engine's coolant cools the coolant by heat exchange with the cooling air drawn in by the cooling fan. Furthermore, the cooling air (exhaust air) that has become hot as a result flows from the engine inside the hood toward the control section at the rear, which could cause the control section to become too hot if left unchecked. However, the partition wall blocks the flow of this exhaust air, preventing the control section from becoming too hot. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-117963 Summary of the Invention [Problem to be solved by the invention]

[0008] As mentioned above, in a work vehicle, the bonnet that covers the engine, etc. and the control section that is equipped with the steering wheel, driver's seat, etc. are separated by a partition wall made up of a heat shield and a spacer cover that covers its outer periphery, or the bonnet and the control section are separated by the front panel of the cabin, etc., to shield the control section from the warm air discharged from behind the bonnet that covers the engine, etc., and improve the driver's comfort in the control section.

[0009] Furthermore, in work vehicles, the control section is supported to prevent vibrations in order to improve the driver's riding comfort against vibrations during driving and vehicle body vibrations, etc. For this reason, the power unit, which covers the engine etc. with a bonnet, and the control section, which has the driver's seat etc., have different vibration systems and must be located apart to prevent vibrations from being transmitted to each other, and when the aforementioned bulkhead is located on the engine side, the spacer cover hides the heat shield etc. to improve the appearance, and also seals the gap that occurs between the front part of the control section and the power unit with a cushioning material such as a seal.

[0010] On the other hand, in such an environment, if an exhaust gas aftertreatment device is installed inside the hood together with the engine, the rear portion of the hood is blocked by the bulkhead and the front panel of the cabin as mentioned above, so the heat generated by the exhaust gas aftertreatment device is trapped above the rear portion of the hood, causing thermal damage to surrounding components. Therefore, as described in Patent Document 1, it has been proposed to provide a heat exhaust hole in the top plate of the hood and exhaust this trapped hot air through the heat exhaust hole.

[0011] However, although providing heat exhaust holes in the top plate of the bonnet located above the exhaust gas after-treatment device can lower the temperature around the exhaust gas after-treatment device, the strength of the bonnet is reduced by providing the heat exhaust holes, so the strength of the bonnet must be improved by using reinforcing members.In addition, the heat exhaust holes provided in the bonnet and the perforated metal that blocks these heat exhaust holes can deteriorate the appearance, and the heat exhaust holes, reinforcing members, and perforated metal can increase the manufacturing costs of the bonnet.

[0012] In addition, the reinforcing member installed below the hood's heat exhaust hole is a plate member formed with an approximately U-shaped cross section, in an attempt to prevent water droplets such as rain that enter through the heat exhaust hole from splashing onto the exhaust gas aftertreatment device.However, this requires the use of a reinforcing member with an approximately U-shaped cross section, and the water droplets must fall outside the unit by running down the intermediate plate, inclined plate, and even the side wall or side wall plate of the hood, so it is not certain whether the water will actually splash onto the exhaust gas aftertreatment device or whether the water droplets will reliably fall outside the unit.

[0013] Therefore, in consideration of the above problems, the present invention aims to provide a work vehicle that can prevent the deterioration of appearance and increase in manufacturing costs when a heat exhaust hole is provided in the hood, etc., when the heat generated by an exhaust gas aftertreatment device that is covered by the hood together with the engine is exhausted through the heat exhaust hole so as not to cause thermal damage to surrounding parts. [Means for solving the problem]

[0014] To solve the above problems, firstly, the work vehicle of the present invention is configured such that the bonnet that covers the engine and exhaust gas after-treatment device is separated from the control section that includes the steering wheel and driver's seat by a heat shield, and the outer periphery of this heat shield is covered by a spacer cover, the exhaust gas after-treatment device that is located above the rear of the engine is covered by the rear part of the bonnet and the front part of the spacer cover that is forward of the heat shield, and heat exhaust holes are provided in the top and side plates of the spacer cover that face the exhaust gas after-treatment device, so that hot air heated to a high temperature by the exhaust gas after-treatment device is exhausted to the outside of the vehicle through the heat exhaust holes. On the other hand, a mounting plate for the exhaust gas after-treatment device is erected at the rear of the engine, and a support plate for attaching the rear of the hood is attached to this mounting plate, and this support plate covers the upper rear portion of the exhaust gas after-treatment device, so that rainwater entering through the heat exhaust hole provided in the top plate portion of the spacer cover does not fall on the exhaust gas after-treatment device due to the downward sloping surface toward the rear of the support plate. It is characterized by:

[0015] Secondly, the work vehicle of the present invention comprises: The heat shield separating the bonnet and the steering section is made up of a mounting plate for the exhaust gas aftertreatment device installed at the rear of the engine and a support plate for supporting the rear of the bonnet, and is formed into a roughly trapezoidal shape by the left and right heat shield plate pieces and the upper heat shield plate piece provided on these plates. It is characterized by:

[0016] Furthermore, the work vehicle of the present invention has a third 、 An upper heat shield plate piece extending upward and rearward is provided on the downward inclined surface of the support plate to which the rear part of the bonnet is attached, and a substantially V-shaped space in a side view formed by the inclined surface of the support plate and the upper heat shield plate piece is formed by the spacer cover. Installed on the top plate It is characterized by being configured as a storage area for rainwater that enters through the heat exhaust hole.

[0017] The work vehicle of the present invention is fourthly characterized in that a drain hose is provided at the bottom of the rainwater storage section, and the drain hose is used to guide and drain rainwater collected in the storage section to the ground. The work vehicle of the present invention is fifthly characterized in that seals are provided at the front and rear ends of the spacer cover, which is formed into a roughly inverted U-shape by the top plate and side plate sections where the heat exhaust holes are provided, and these front and rear seals eliminate any gaps that may occur between the rear end of the hood and the front end of the steering section. Furthermore, the work vehicle of the present invention is sixthly characterized in that the top plate of the spacer cover is sloped downward toward the rear. [Effects of the Invention]

[0018] According to the work vehicle of the present invention, the hood, which covers the engine and exhaust gas after-treatment device, and the control section, which is equipped with the steering wheel and driver's seat, are separated by a heat shield, and the outer periphery of this heat shield is covered by a spacer cover.The exhaust gas after-treatment device, which is located above and toward the rear of the engine, is covered by the rear part of the hood and the front part of the spacer cover, which is forward of the heat shield, and heat exhaust holes are provided in the top and side plates of the spacer cover facing the exhaust gas after-treatment device, so that hot air heated to a high temperature by the exhaust gas after-treatment device is exhausted outside the aircraft through the heat exhaust holes.

[0019] Therefore, the hot air, which has become hot due to the heat generated by the exhaust gas aftertreatment device located above and toward the rear of the engine, can be carried on the exhaust air flowing rearward by the engine's cooling fan and quickly exhausted outside the aircraft through heat exhaust holes located in the top and side panels of the spacer cover forward of the heat shield that separates it from the control section behind it, thereby lowering the temperature inside the hood and preventing heat damage to peripheral parts of the exhaust gas aftertreatment device, etc.

[0020] In addition, the heat exhaust holes that exhaust hot air outside the aircraft are provided in the top and side panels facing the exhaust gas aftertreatment device of the spacer cover that covers the outer periphery of the heat shield that separates the hood and the control section, so even if the spacer cover becomes weaker due to the provision of the heat exhaust holes, the spacer cover serves as a cosmetic cover that hides the heat shield and improves the appearance, and since strength is not a major issue to begin with, there is no need to reinforce it with reinforcing material. Furthermore, for safety reasons, if the heat exhaust holes are formed as multiple slit-like elongated holes that are difficult for hands to reach, it can be used to add variety to the spacer cover and improve its appearance.

[0021] Furthermore, according to the work vehicle of the present invention, a mounting plate for the exhaust gas after-treatment device is erected at the rear of the engine, and a support plate for mounting the rear part of the hood is attached to the mounting plate, and the support plate covers the upper part of the rear part of the exhaust gas after-treatment device, and the spacer cover Installed on the top plate Rainwater entering through the exhaust vent The downward slope toward the rear of the support plate It is configured so that it does not fall on the exhaust gas aftertreatment device.

[0022] In other words, the exhaust gas aftertreatment device, which is located above the rear of the engine, is covered by the rear of the hood and the front of the spacer cover, which is forward of the heat shield, and the heat exhaust holes in the top plate of the spacer cover face above the rear of the exhaust gas aftertreatment device, so rainwater that enters the heat exhaust holes in the top plate of the spacer cover falls on the rear of the exhaust gas aftertreatment device.

[0023] However, because the upper rear portion of the exhaust gas after-treatment device is covered by a support plate that attaches the rear of the hood, rainwater can be prevented from falling on the exhaust gas after-treatment device, without affecting filter regeneration or impairing forward visibility, for example. Moreover, the hood support plate can prevent rainwater from falling on the exhaust gas after-treatment device, which is convenient because there is no need to provide a separate cover to prevent rainwater from falling on it.

[0024] Furthermore, according to the work vehicle of the present invention, heat-shielding plate pieces are provided on the mounting plate of the exhaust gas aftertreatment device and on the support plate to which the rear of the hood is attached, thereby forming a heat-shielding plate separating the hood and the steering section, and an upper heat-shielding plate piece extending rearward and upward is provided on the downward sloping surface toward the rear of the support plate to which the rear of the hood is attached, and the space formed by the sloping surface of the support plate and the upper heat-shielding plate piece, which is approximately V-shaped in side view, is configured as a storage area for rainwater that enters through the heat exhaust hole of the spacer cover.

[0025] Therefore, a heat shield plate that covers the approximately trapezoidal rear surface of the bonnet without any gaps can be formed by utilizing the plate surfaces of the mounting plate provided to mount the exhaust gas aftertreatment device to the rear of the engine and the support plate provided to attach the rear of the bonnet to the engine, and by filling the remaining gaps with heat shield plate pieces, thereby reducing material costs.

[0026] Furthermore, a storage section is provided to store rainwater that falls on the support plate that attaches the rear of the hood, so that rainwater that has entered through the heat exhaust holes of the spacer cover and falls on the support plate as a guide member does not fall on sensors that are not waterproofed, for example, and cause problems. This storage section is formed by providing an upper heat shield plate piece that faces rearward and upward on the downward sloping surface that slopes toward the rear of the support plate, and the space that is formed by the sloping surface of the support plate and the upper heat shield plate piece is approximately V-shaped in side view and can be used as a rainwater storage section.

[0027] The work vehicle of the present invention is configured so that a drain hose is provided at the bottom of the rainwater storage section, and the rainwater collected in the storage section is guided to the ground by the drain hose and drained away. Therefore, the rainwater can be guided to the ground and drained away using the drain hose before it overflows from the storage section, preventing problems such as rainwater or car wash water collecting on surrounding parts and causing them to rust.

[0028] Furthermore, according to the work vehicle of the present invention, seals are provided at the front and rear ends of the spacer cover, which is formed into a generally inverted U shape by the top plate and side plate portions where the heat exhaust holes are provided, and these front and rear seals eliminate gaps that occur between the rear end of the hood and the front end of the steering section. Therefore, the seal provided at the front end of the spacer cover eliminates gaps that are provided to prevent shock absorption when the hood is opened and closed, and the seal provided at the rear end of the spacer cover can eliminate gaps caused by differences in vibration systems with the steering section, and by sealing such gaps with seals, it is possible to prevent rainwater from entering the hood from sources other than the aforementioned heat exhaust holes.

[0029] Furthermore, according to the work vehicle of the present invention, the top plate of the spacer cover is sloped downward toward the rear. Therefore, even if the height of the rear portion of the hood is increased by installing the exhaust gas aftertreatment device above the rear of the engine, creating a step between the spacer cover and the hood, this step can be eliminated by sloping the top plate of the spacer cover downward toward the rear, and the rear end of the top plate of the spacer cover and the front of the steering unit act as drainage channels that channel rainwater to the left and right, reducing the amount of rainwater that gets into the heat exhaust port. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. 2 is a perspective view of the engine and the DPF provided in the engine. [Figure 4] FIG. 2 is a perspective view showing the hood in an open state. [Figure 5] This is a perspective view of the control panel as seen from the driver's seat side. [Figure 6] FIG. [Figure 7] FIG. 2 is a perspective view of the driving unit as seen from the rear right side. [Figure 8] FIG. 2 is a perspective view of the driving unit as seen from the rear left side. [Figure 9]FIG. [Figure 10] FIG. [Figure 11] FIG. 2 is a longitudinal cross-sectional view of the driving unit near the rear. [Figure 12] FIG. 10 is a longitudinal cross-sectional view of the main part where the spacer cover is provided between the driving part and the steering part. [Figure 13] FIG. 2 is a perspective view showing the structure of the heat shield plate as viewed obliquely from the front. [Figure 14] FIG. 4 is a perspective view showing the structure of the heat shield plate as seen obliquely from behind. [Figure 15] FIG. 10 is a front view showing the upper portion of the tractor according to the second embodiment. [Figure 16] FIG. 10 is a plan view showing the portion of the tractor near the driving unit according to the second embodiment. [Figure 17] FIG. 10 is a side view showing the side of the tractor of the second embodiment near the driving unit. [Figure 18] FIG. 10 is a longitudinal cross-sectional view of a main part of the spacer cover of the second embodiment, which is provided between the driving part and the steering part. [Figure 19] 1A and 1B are perspective views showing the state in which the fuel filter and the water separator are attached, with FIG. 1A being a perspective view showing the state in which they are covered with a cover, and FIG. 1B being a perspective view showing the state in which the cover is removed. DETAILED DESCRIPTION OF THE INVENTION

[0031] 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 serving as a work vehicle has a vehicle body (machine body) formed by integrally connecting an engine 2 and front and rear transmission cases 3, 4. A front axle case 6 is pivotally supported on the underside of chassis brackets 5, which are fixed to the left and right near the bottom of the engine 2 and extend forward, so as to be able to swing left and right. Front axle cases 7 are attached to the left and right ends of the front axle case 6, respectively, and each front axle case 7 pivotally supports a front axle 8, with left and right front wheels 9 attached to the front axle 8 being steerable.

[0032] Meanwhile, rear axle cases fixed to the left and right sides of the rear transmission case 4 support rear axles 10, respectively, and left and right rear wheels 11 are attached to each rear axle 10. In addition, a well-known three-point linkage mechanism consisting of a top link 12 and left and right lower links 13 is provided at the rear of the vehicle body. This three-point linkage mechanism connects a work machine such as a rotary tiller to the vehicle body, and the work machine is attached to the top of the rear transmission case 4 and is capable of being raised and lowered via left and right lift arms of a cylinder case equipped with lifting cylinders inside the cylinder case, and lift rods whose ends are connected to the tips of the lift arms and midway through the lower links 13.

[0033] Furthermore, as shown in Figure 3, the aforementioned engine 2 is a water-cooled four-stroke diesel engine, and in response to stricter exhaust gas regulations, this engine 2 is equipped with a common rail fuel injection system, a turbocharger, an 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.Furthermore, nitrogen oxides and particulate matter that cannot be completely purified by the engine itself are removed using a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF) as exhaust gas aftertreatment devices.

[0034] For this reason, a mounting plate 14 is erected at the rear of the cylinder head of the diesel engine 2, and a cylindrical DPF case 16 containing a DOC and DPF is attached horizontally, with its longitudinal direction in the left-right direction, via a holder 15, to the upper front side of this mounting plate 14. Therefore, gas exhausted from the engine 2 is introduced from an inlet side near the lower left of the DPF case 16, which is provided at the top and rear of the engine 2, and then discharged outside the aircraft from an outlet side near the front right of the DPF case 16 via a tailpipe (not shown).

[0035] An auxiliary equipment bracket 17 consisting of a bottom plate and stays is attached to the upper surface of the chassis bracket 5, and this auxiliary equipment bracket 17 is provided with a radiator 18 that cools the cooling water for the engine 2, an air cleaner 19 that supplies clean air to the engine 2, an oil cooler 20, an intercooler 21, a battery 22, etc. (see Figure 10).

[0036] The engine 2, DPF case 16, and engine accessories are covered by a hood 23, which is formed by integrally connecting a generally rectangular ceiling portion 23a, left and right side plate portions 23b, an inner grill 26 and an outer grill 27 which are provided on the front sides with air vents 24 and headlamps 25, and a front cover 28 provided below the inner and outer grills 26 and 27 using mounting brackets, etc. A front plate 30a of a hinge 30 which is provided with a fulcrum shaft 29 is attached to the inside rear part of the ceiling portion 23a of the hood 23 with bolts, and a rear plate 30b of the hinge 30 is attached to the top of a support plate 31 with bolts (see FIG. 11).

[0037] Furthermore, because the support plate 31 is attached with bolts to the upper part of the mounting plate 14 of the DPF case 16, the bonnet 23 is ultimately supported so as to be rotatable about a fulcrum shaft 29 in the left-right direction located directly above the DPF case 16, which is provided above and toward the rear of the engine 2, and the front part of the bonnet can be opened and closed as shown in FIG. 4. When the front cover 28 of the bonnet 23 is disengaged from a pin and a bonnet catch (not shown) provided on the accessory bracket 17 and the front part of the bonnet 23 is lifted, the bonnet 23 can be held in an open state by a gas spring 32 provided across the top of the engine 2 and the ceiling part 23a of the bonnet 23.

[0038] A control section is provided behind the driving section, which covers the engine 2, DPF case 16, etc. with the hood 23. This control section has a driver's seat 33 located in the center near the rear of the driver's seat, and is also composed of a floor frame 34 that is supported above the front transmission case 3 and the rear axle case in a vibration-isolating manner, left and right fenders 35 that are attached to the floor frame 34 and cover the front to upper portions of the rear wheels 11, and a safety frame 36 that is erected behind the driver's seat 33 so as to be able to be raised and lowered.

[0039] A gate-shaped column frame 38 is erected in front of the floor frame 34, facing a rear cover (spacer cover) 37 provided behind the hood 23, which will be described later. A steering handle 39 for steering the left and right front wheels 9 is mounted on a column mounting bracket provided near the top of the column frame 38 so that its tilt is adjustable. Furthermore, a fully hydraulic power steering unit operated by the steering handle 39 is attached to the upper surface of the front transmission case 3 near the center.

[0040] 5, a combination switch 40, a quick-up lever 41 for raising and lowering the work machine, an engine control lever 42, and a forward / reverse lever 43 are provided below the steering handle 39, and the steering shaft and steering column are entirely covered by a cover 44. Furthermore, a clutch pedal 45 is mounted on the left side of the column mounting bracket as viewed from the driver's seat 33, and left and right brake pedals are mounted on the right side, each hanging down, and a parking brake lever 46 is provided near the center.

[0041] The column mounting bracket in front of the steering wheel 39 is provided with a cover that covers it, and this cover is composed of a panel cover 47 provided near the top and a rear panel cover 48 that covers the rear surface near the bottom. An instrument panel 49 is attached to an opening provided on the rear surface near the center of the top of the panel cover 47, so that when an operator sits in the driver's seat 33 and looks forward, the operator can see the instrument panel 49 from between the rim and hub of the steering wheel 39, and the face of the instrument panel 49 is tilted relative to the panel cover 47 so that it is approximately perpendicular to the operator's line of sight forward.

[0042] The peripheral edge of the opening in panel cover 47 where meter panel 49 is attached is formed into a visor (sunshade) that bulges backward, and the upper surface near the center of meter panel 49 as a whole is inclined downward toward the front. Also, behind the opening where meter panel 49 is attached, on the left and right sides of the opening where cover 44 of steering handle 39 fits, there are provided a left front unit having switches for turning on and off various automatic controls (double speed, backup, turning up, etc.) and LEDs that indicate their on / off status, and a right front unit 50 having operation switches for setting the display screen of the liquid crystal display provided on meter panel 49, etc.

[0043] Furthermore, a hazard lamp switch 51 and a horn switch are provided on the panel covers 47 above and below the left front unit, and a starter switch 52 is provided on the panel cover 47 below the right front unit 50. In addition to the switches and control levers described above, the tractor 1 also has operating devices such as travel and PTO shift levers and pedals, as well as 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 33 and on the floor surface of the floor frame 34.

[0044] Having explained the outline of the tractor 1 above, next we will explain the regeneration of the diesel particulate filter (DPF) provided in the diesel engine 2 and switches and the like related to that regeneration. First, the diesel particulate filter collects soot (SOOT) contained in the exhaust gas of the diesel engine 2. In addition, an electronic control unit (ECU) that controls the diesel engine 2 estimates the amount of soot accumulated on the diesel particulate filter (accumulation amount ratio) based on exhaust temperature sensors 53 to 55 and an exhaust pressure differential sensor 56 provided at the inlet of the DOC and the inlet and outlet of the DPF.

[0045] 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 higher. Here, if the automatic regeneration request is issued and the engine speed is high and the coolant temperature is high, the common rail fuel injection system mixes unburned fuel into the exhaust pipe by post injection, and the diesel oxidation catalyst (DOC) 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.

[0046] Furthermore, regardless of the automatic regeneration described above, the engine 2 ECU issues a manual regeneration request if the soot accumulation ratio is 100 or higher, and in this case, if the ratio is between 100 and 120 in the early stage, engine output is not limited, but if the ratio is between 120 and 140 in the later stage, engine output is limited to 50 percent and the maximum rotation speed to 1500 rpm. Then, when manual regeneration is commanded by the operator, the main injection and post injection amounts are increased compared to automatic regeneration, the exhaust temperature is raised further, and the regeneration speed of the diesel particulate filter is accelerated.

[0047] Furthermore, the ECU of engine 2 issues an over-deposition request if the soot deposition ratio is 140 or more, and in this case, if the early stage is between 140 and 160, the ECU controls the engine output to be limited by first setting the engine output to 50 percent and limiting the rotation to 1500 rpm in the first stage, and then setting the rotation limit to 1200 rpm in the second stage after 7200 seconds. Also, if the later stage is 160 or more, the ECU also sets the engine output to 50 percent and limiting the rotation to 1500 rpm in the first stage, and then setting the rotation limit to 1200 rpm in the second stage after 3600 seconds.

[0048] When the engine 2 ECU regenerates the diesel particulate filter, the exhaust gases and tailpipe become hot, and if the above-mentioned 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 greenhouse), there is a risk of fire or gas poisoning, 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 materials nearby, and the parking brake must be applied to stop the vehicle, and then engine 2 must be put into an idling state before manual regeneration can be performed.

[0049] Furthermore, if the above-mentioned excessive deposition request is issued without being able to properly perform automatic or manual regeneration of the diesel particulate filter, the worker will be unable to regenerate the diesel particulate filter himself, so he will have to quickly stop the work and leave it to a service technician or the like to attempt regeneration using a service tool or the like, or in the worst case, have the diesel particulate filter repaired or replaced.

[0050] 5, the tractor 1 is provided with a DPF regeneration lamp and an engine malfunction lamp that notify the status of the DPF (request / regeneration / abnormal) on the meter panel 49 of the panel cover 47 regarding the regeneration of the diesel particulate filter as described above. Also provided are a manual regeneration switch that issues a command for manual regeneration, a regeneration prohibition switch that issues a command for prohibiting regeneration, a manual regeneration lamp that notifies the request and execution of manual regeneration, and a regeneration prohibition lamp that notifies the execution of regeneration prohibition.

[0051] The manual regeneration switch and manual regeneration lamp, and the regeneration inhibit switch and regeneration inhibit lamp, each use a push button switch with an LED bulb that combines the lamp and switch into one unit, and these two switches, manual regeneration switch (with lamp) 57 and regeneration inhibit switch (with lamp) 58, are attached to the rear surface of a synthetic resin sub-panel cover 59. The sub-panel cover 59 is provided near the center of the upper front part of the panel cover 47, so that the switches and lamps provided on the meter panel 49 of the panel cover 47 and the sub-panel cover 59 are within the forward field of view of the operator sitting in the driver's seat 33.

[0052] The above has described the regeneration of the DPF provided in the diesel engine 2 and the switches and other related devices for regeneration. However, as the DPF regeneration progresses, the DPF case 16 generates heat, which in turn heats the air surrounding the DPF case 16. This heat builds up in the areas where the DPF case 16 is located, particularly above the rear of the hood 23 and above the front of the spacer cover 37, causing thermal damage to surrounding sensors and rubber parts. Therefore, measures to address this issue will be described below.

[0053] First, a heat shield plate is provided between the rear of the hood 23, which covers the engine 2 and DPF case 16, and the handle frame 38 of the control section, separating the two to prevent the warm cooling air (exhaust air) discharged by the cooling fan 60 of the engine 2 from flowing toward the control section and impairing occupant comfort. As shown in Figures 6 to 12, this heat shield plate serves both as the mounting plate 14 of the DPF case 16 erected at the rear of the engine 2 and as the support plate 31 that supports the rear of the hood 23, and is formed into a substantially trapezoidal shape with left and right heat shield plate pieces 60 attached to these with bolts and an upper heat shield plate piece 61 fixed to the support plate 31.

[0054] 13 and 14, the left and right heat shield plate pieces 60 have mounting portions 60a provided on their upper parts attached with bolts to left and right pedestals 31a fixed to the support plate 31, and mounting portions 60b provided on their lower parts attached with bolts to left and right cover mounting brackets 62, which are in turn attached with bolts near the bottom of the mounting plate 14 of the DPF case 16. Furthermore, the left and right pedestals 31a fixed to the support plate 31 extend rearward, and vibration-isolating rubber 63 is provided on these extensions 31b, which connect to the upper part of the column frame 38 of the control section.

[0055] The outer periphery of the heat shield plate provided between the rear of the bonnet 23 and the column frame 38 of the steering section is covered with a spacer cover 37 with a slightly wider front-to-rear width provided behind the bonnet 23. In this case, four angled metal fittings (not shown) are fixed to the inner front side of the spacer cover 37, which is formed by bending a steel plate into a roughly inverted U shape.

[0056] Meanwhile, left and right pedestals 31a fixed to the support plate 31 are provided with elongated holes, and upper fittings 64 are attached with four bolts b1 so that their positions can be adjusted in the front-to-back direction. Lower fittings 65 are attached to the left and right cover mounting brackets 62 with bolts so that their positions can be adjusted in the front-to-back direction. The front faces of the fittings fixed to the spacer cover 37 are then overlapped with the front faces of these upper fittings 64 and lower fittings 65, and the front portion of the spacer cover 37 is attached with four bolts b2. The lower part of the spacer cover 37 is abutted against the outer surfaces of the left and right lower fittings 65 and attached with two bolts b2.

[0057] Heat exhaust holes 37c, 37d are provided in the top plate portion 37a and the left and right side plate portions 37b of the spacer cover 37 facing the DPF case 16, and hot air heated by the DPF 16 is exhausted to the outside of the aircraft through these heat exhaust holes 37c, 37d. More specifically, eight heat exhaust holes 37c are provided in the top plate portion 37a of the spacer cover 37, each formed as an elongated slit with its longitudinal direction running left and right. Seven heat exhaust holes 37d are provided in each of the left and right side plate portions 37b of the spacer cover 37, each formed as an elongated slit with its longitudinal direction running diagonally upward and rearward.

[0058] Additionally, seals 66, 67 formed from weather strips are attached to the front and rear ends of the spacer cover 37, and these front and rear seals 66, 67 seal and eliminate any gaps that may occur between the rear end of the hood 23, which opens and closes, and the front end of the steering section (column frame 38). Furthermore, holes in the top plate portion 37a of the spacer cover 37 that are drilled to allow the removal of the four bolts b1 that attach the upper fitting 64 to the support plate 31 are closed with caps 68.

[0059] The support plate 31, which supports the rear of the hood 23, has a downwardly inclined surface 31b that extends rearward from the upper portion where the rear plate 30b of the hinge 30 is attached to the lower portion where the DPF case 16 is attached to the mounting plate 14, covering the rear portion of the DPF case 16 from above. An upper heat shield plate piece 61 that extends rearward and upward is fixed to the middle of the downwardly inclined surface 31b of the support plate 31. Furthermore, the left and right ends of this upper heat shield plate piece 61 are closed by the bases 31a of the support plate 31.

[0060] Therefore, rainwater or car wash water that seeps in through the heat exhaust holes 37c provided in the top plate portion 37a of the spacer cover 37 falls from the upper part of the support plate 31 onto the downward inclined surface 31b, and is finally collected in a space (storage portion) 69 that is approximately V-shaped in side view and formed by the inclined surface 31b of the support plate 31 and the upper heat shield plate piece 61. In addition, a hole is drilled near the bottom of the center in the left-right direction of the upper heat shield plate piece 61 (at the bottom of the storage portion 69), and the starting end of the drain hose 70 is attached to this hole using instant adhesive so that it reaches the storage portion 69 from the rear via a grommet 71.

[0061] Furthermore, the end of the drain hose 70 is led from the rear of the mounting plate 14 to the left rear side of the engine 2 using an appropriate mounting band to select the piping location, and is ultimately configured to drain rainwater that accumulates in the reservoir 69 toward the ground. On the left and right lower sides of the hood 23 are provided fixed covers 71 that stand up and are attached to the accessory bracket 17, and side covers 72 that have their front parts attached to the accessory bracket 17 near the radiator with knobbed bolts 72 and are fixed by inserting the pins 62a of the cover mounting bracket 62 described above into mounting holes provided at their rear ends.

[0062] Therefore, the cooling fan 73 of the engine 2 draws in cooling air from the vent 24 of the hood 23, and the cooling air exchanges heat with the cooling water of the engine 2 in the core of the radiator 18 to become hot air, which is then exhausted and passes around the engine 2 inside the hood 23 to the heat shield plate provided at the rear. Then, because the shield plate blocks the flow of the exhaust air toward the control section, most of the exhaust air is discharged outside the aircraft through the exhaust holes provided below the engine 2 and in the side cover 72.

[0063] However, the pressure (air pressure) inside the hood 23 where the engine 2 is mounted is high due to the exhaust air, and part of the exhaust air flows around the DPF case 16 located above and toward the rear of the engine 2, and then passes through heat exhaust holes 37c and 37d located in the top plate portion 37a and the left and right side plate portions 37b of the spacer cover 37 to be discharged to the outside of the aircraft. Therefore, when the DPF case 16 generates heat as the DPF regenerates and the air surrounding the DPF case 16 is heated by this, this heated air is discharged to the outside of the aircraft together with the exhaust air through the heat exhaust holes 37c and 37d, eliminating the risk of thermal damage to surrounding sensors and rubber parts.

[0064] The first embodiment relating to the countermeasure against heat damage to the exhaust gas aftertreatment device of the engine 2, which is a feature of the present invention, has been described above. However, regarding the tractor 1 according to the second embodiment, in which the engine 2 is changed from four cylinders to three cylinders and the control section is covered by a cabin, as shown in Figures 15 to 18, in this tractor 1, the control section including the driver's seat 33 and steering handle 39 is covered by a cabin 73. The cabin 73 is attached to the vehicle body by being supported in a vibration-isolating manner by the front transmission case 3 and the rear axle case.

[0065] The configuration in which the engine 2 and the DPF case 16 serving as an exhaust gas aftertreatment device are covered by the hood 23 is no different from that of the tractor 1 of the first embodiment, but since this is a slightly smaller model, the rear portion of the spacer cover 37 covering the outer periphery of the heat shield is tightly attached to the front of the cabin 73, and the top plate portion 37a is extended forward as is, so that the hood 23 is used for both purposes. As a result, a step is created between the rear end of the ceiling portion 23a of the hood 23 and the front end of the top plate portion 37a of the spacer cover 37, and the gap created by this step can also be used as a heat exhaust port for hot air.

[0066] However, because there is a risk that rainwater or car wash water may enter the hood 23 from this step, the front end of the top plate portion 37a of the spacer cover 37 is inclined downward toward the rear from the rear end of the ceiling portion 23a of the closed hood 23 to reach the front of the cabin 73. Therefore, even if the height of the rear portion of the hood 23 is increased by providing the exhaust gas aftertreatment device above and toward the rear of the engine 2, causing a step to occur between the spacer cover 37 and the top plate portion 37a of the spacer cover 37, this step can be eliminated by providing the top plate portion 37a of the spacer cover 37 with an inclination downward toward the rear, and also, changing the shape of the spacer cover 37 gives a change to the appearance, improving its aesthetics.

[0067] In addition, since the top plate portion 37a of the spacer cover 37 is inclined downward, hot air can be easily released rearward through the heat exhaust holes 37c, and the swing fulcrum position of the wiper 75 provided on the front window 74 of the cabin 73 can be lowered, so a larger wiper 75 can be installed to ensure the driver's forward visibility.

[0068] Furthermore, the weatherstrip 67 attached to the rear end of the spacer cover 37 is normally constrained by the requirement that the shape of the spacer cover 37, which is its parent, must match the column frame 38 so that it fits tightly against the portal-shaped frame of the column frame 38 of the control section. However, this time the weatherstrip 67 attached to the rear end of the spacer cover 37 is modified so that it fits tightly against the glass surface of the front window 74 of the cabin 73, so the shape of the spacer cover 37 can be determined without changing the shape of the column frame 38.

[0069] Furthermore, the top plate portion 37a of the spacer cover 37 is inclined downward and fits tightly against the glass surface of the front window 74 of the cabin 73 via the weather strip 67, so that the rear end of the top plate portion 37a of the spacer cover 37 and the front surface of the control section act as a drainage channel that flows rainwater to the left and right, thereby reducing the amount of rainwater that enters the heat exhaust hole 37c.

[0070] As shown in Figure 19, a fuel filter 77 and a water separator 78 that separates water contained in the fuel are provided in the engine fuel supply path that supplies diesel fuel stored in left and right fuel tanks 76 located below the control section to the engine 2. The fuel filter 77 and water separator 78 are attached via brackets to the frame of the control section behind the right front wheel 8 to allow for easy fuel filter replacement and drainage, and are covered with a cover 79 that can be attached and detached with bolts.

[0071] However, as the vehicle is driven, there is a risk that mud adhering to the right front wheel 8 will accumulate on the upper surface of cover 79, which would require the effort of removing the accumulated mud when washing the vehicle, so the upper surface 79a of cover 79 is sloped downward toward the front, making it easier for accumulated mud to slide down to the ground from the upper surface 79a down the front surface 79b when washing the vehicle. Also, as shown in Figure 3, a cover 80 is provided between the DPF case 16 and the top of the engine 2 to block hot air from the DPF case 16, and as shown in Figure 4, a cover 81 is provided to cover the exhaust elbow and other parts located near the left side of the DPF case 16, which prevents workers from coming into contact with hot parts and getting burned by this cover 81 when the hood 23 is opened.

[0072] Furthermore, the spacer cover 37 can be removed by removing the cap 68 provided on the top plate portion 37a of the spacer cover 37 and removing the four bolts b1, or by opening the hood 23 and removing the bolts b2 attached to the front and outer surface of the lower metal fitting 65. In this state, the hood 23 can be removed by removing the bolts attaching the rear plate 30b of the hinge 30 to the support plate 31 and further removing the gas spring 32 attached to the ceiling portion 23a of the hood 23. Therefore, removing the hood 23 in this way makes it easier to replace the DPF 16 with a new one or to perform maintenance on the engine 2.

[0073] An embodiment of the present invention has been described above, but to summarize here the measures against heat damage to the exhaust gas aftertreatment device that are a feature of the present invention, first, the tractor 1 has a heat shield separating the hood 23 that covers the engine 2 and the exhaust gas aftertreatment device 16 from the control section that includes the steering wheel 39 and the driver's seat 33, and the outer periphery of this heat shield is covered by a spacer cover 37. Furthermore, the exhaust gas aftertreatment device 16, which is provided above and toward the rear of the engine 2, is covered by the rear side of the hood 2 and the front side of the spacer cover 37 forward of the heat shield, and heat exhaust holes 37c, 37d are provided in the top plate portion 37a and the side plate portion 37b of the spacer cover 37 facing the exhaust gas aftertreatment device 16, so that hot air heated to a high temperature by the exhaust gas aftertreatment device 16 is exhausted to the outside of the machine through the heat exhaust holes 37c, 37d.

[0074] Therefore, hot air that has become hot due to the heat generated by the exhaust gas aftertreatment device 16 located above and toward the rear of the engine 2 can be carried on the exhaust air that flows rearward by the cooling fan 73 of the engine 2 and quickly exhausted outside the aircraft from the heat exhaust holes 37c, 37d provided in the top plate portion 37a and the side plate portion 37b of the spacer cover 37 forward of the heat shield that separates it from the control section behind it, thereby lowering the temperature inside the hood 2 and preventing heat damage to peripheral parts of the exhaust gas aftertreatment device 16, etc.

[0075] Furthermore, the heat exhaust holes 37c, 37d that exhaust hot air to the outside of the aircraft are provided in the top plate portion 37a and the side plate portion 37b of the spacer cover 37 that covers the outer periphery of the heat shield that separates the hood 2 from the control panel, which face the exhaust gas aftertreatment device 16. Therefore, even if the spacer cover 37 becomes weaker due to the provision of the heat exhaust holes 37c, 37d, the spacer cover 37 serves as a cosmetic cover that hides the heat shield and improves the appearance, and since strength is not a major issue to begin with, there is no need to reinforce it with a reinforcing material. Furthermore, for safety reasons, if the heat exhaust holes 37c, 37d are formed as multiple slit-like elongated holes that are difficult for hands to reach, they can be used to add variety to the spacer cover 37 and improve its appearance.

[0076] In addition, the tractor 1 has a mounting plate 14 for the exhaust gas after-treatment device 16 erected at the rear of the engine 2, and a support plate 31 for attaching the rear of the bonnet 2 to this mounting plate 14, which covers the upper rear part of the exhaust gas after-treatment device 16 with this support plate 31, so that rainwater entering through the heat exhaust hole 37c of the spacer cover 37 does not fall on the exhaust gas after-treatment device 16.

[0077] That is, the exhaust gas aftertreatment device 16, which is provided above and near the rear of the engine 2, is covered by the rear of the hood 23 and the front of the spacer cover 37, which is forward of the heat shield, and the heat exhaust hole 37c provided in the top plate portion 37a of the spacer cover 37 faces above and near the rear of the exhaust gas aftertreatment device 16, so that rainwater that enters the heat exhaust hole 37c provided in the top plate portion 37a of the spacer cover 37 falls on the rear of the exhaust gas aftertreatment device 16.

[0078] However, because the upper rear portion of the exhaust gas after-treatment device 16 is covered by the support plate 31 to which the rear of the bonnet 23 is attached, rainwater can be prevented from falling on the exhaust gas after-treatment device 16, and this does not, for example, affect filter regeneration or reduce forward visibility due to the generation of water vapor. Moreover, the support plate 31 of the bonnet 23 can prevent rainwater from falling on the exhaust gas after-treatment device 16, which is advantageous because there is no need to provide a new cover to prevent rainwater from falling on it.

[0079] Furthermore, the tractor 1 is provided with heat shield plate pieces 60, 61 on the mounting plate 14 of the exhaust gas aftertreatment device 16 and the support plate 31 to which the rear of the hood 23 is attached, thereby forming a heat shield plate separating the hood 23 from the steering section, and an upper heat shield plate piece 61 extending rearward and upward is provided on the downward sloping surface 31b extending rearward of the support plate 31 to which the rear of the hood 23 is attached, and the approximately V-shaped space in side view formed by the sloping surface 31b of the support plate 31 and the upper heat shield plate piece 61 is formed as a storage section 69 for rainwater that enters through the heat exhaust hole 37c of the spacer cover 37.

[0080] Therefore, a heat shield plate that covers the approximately trapezoidal rear surface of the bonnet 23 without any gaps can be formed by utilizing the plate surfaces of the mounting plate 14 that is provided to mount the exhaust gas aftertreatment device 16 at the rear of the engine 2 and the support plate 31 that is provided to mount the rear of the bonnet 23 to the engine 2, and by filling the remaining gaps with heat shield plate pieces 60, 61, thereby reducing material costs.

[0081] Furthermore, to prevent rainwater that falls on the support plate 31, which mounts the rear of the hood 23, from entering through the heat exhaust holes 37c of the spacer cover 37 and using the support plate 31 as a guide member to fall on sensors or the like that are not waterproofed, a storage section 69 is provided to store rainwater that falls on the support plate 31. This storage section 69 is formed by providing an upper heat shield plate piece 61 that faces rearward and upward on the downward inclined surface 31b facing rearward of the support plate 31, and the space that is formed by the inclined surface 31b of the support plate 31 and the upper heat shield plate piece 61 in a substantially V-shaped shape in side view can be configured as the rainwater storage section 69.

[0082] The tractor 1 is configured so that a drain hose 70 is provided at the bottom of the rainwater storage section 69, and the drain hose 70 guides rainwater collected in the storage section 69 to the ground and drains it. This allows the rainwater to be guided to the ground and drained using the drain hose 70 before it overflows from the storage section 69, preventing problems such as rainwater or car wash water collecting on surrounding parts and causing them to rust. The drain hose 70 is provided near the bottom of the upper heat shield plate piece 61 to catch and easily drain water that flows rearward during forward travel. Furthermore, because the drain hose 70 is attached using a grommet 71, there is no need for a structure such as welding an iron pipe connecting the drain hose 70 to the upper heat shield plate piece 61, thereby reducing costs.

[0083] Furthermore, in the tractor 1, seals 66, 67 are provided at the front and rear ends of the spacer cover 37, which is formed in a generally inverted U shape by the top plate portion 37a and side plate portion 37b, in which the heat exhaust holes 37c, 37d are provided, and these front and rear seals 66, 67 eliminate gaps that occur between the rear end of the bonnet 23 and the front end of the steering section. Therefore, the seal 66 provided at the front end of the spacer cover 37 eliminates gaps that are provided to prevent shock absorption when the bonnet 23 is opened and closed, and the seal 67 provided at the rear end of the spacer cover 37 can eliminate gaps due to differences in the vibration system with the steering section, and by closing such gaps with the seals 66, 67, it is possible to prevent rainwater from entering the bonnet 23 from anywhere other than the heat exhaust holes 37c, 37d.

[0084] Furthermore, in the tractor 1, the top plate 37a of the spacer cover 37 is inclined downward toward the rear. Therefore, even if the height of the rear portion of the hood 23 is increased by providing the exhaust gas aftertreatment device 16 above and toward the rear of the engine 2, causing a step between the spacer cover 37 and the hood 23, this step can be eliminated by providing the top plate 37a of the spacer cover 37 inclined downward toward the rear, and the rear end of the top plate 37a of the spacer cover 37 and the front of the steering unit serve as drainage channels that flow rainwater to the left and right, reducing the amount of rainwater entering the heat exhaust hole 37c. [Explanation of symbols]

[0085] 1 Tractor (work vehicle) 2. Diesel engine 14 Mounting plate 16 DPF case (exhaust gas aftertreatment device) 23 Hood 31 Support plate 33 Driver's seat 37 Spacer cover 37c Heat exhaust hole 37d heat exhaust hole 39 Steering wheel 60 Heat shield plate piece 61 Heat shield plate piece 69 Storage section 79 Drain hose

Claims

1. A work vehicle in which a hood covering the engine and exhaust gas after-treatment device is separated from a control area equipped with a steering wheel and a driver's seat by a heat shield, and the outer periphery of this heat shield is covered by a spacer cover, in which the exhaust gas after-treatment device located above the rear of the engine is covered by the rear of the hood and the front of the spacer cover forward of the heat shield, and heat exhaust holes are provided in the top and side plates of the spacer cover facing the exhaust gas after-treatment device so that hot air heated to a high temperature by the exhaust gas after-treatment device is exhausted outside the aircraft through the heat exhaust holes, a mounting plate for the exhaust gas after-treatment device is erected at the rear of the engine, and a support plate for attaching the rear of the hood is attached to this mounting plate, and this support plate covers the upper rear of the exhaust gas after-treatment device, and rainwater entering through the heat exhaust hole in the top plate of the spacer cover is prevented from falling on the exhaust gas after-treatment device by the downward sloping surface toward the rear of the support plate.

2. The heat shield separating the hood and the operating section is formed using a mounting plate for an exhaust gas aftertreatment device that is erected at the rear of the engine and a support plate that supports the rear of the hood, and is characterized in that it is formed into an approximately trapezoidal shape by left and right heat shield plate pieces and an upper heat shield plate piece that are attached to these plates.

3. A work vehicle as described in Claim 2, characterized in that an upper heat-shielding plate piece extending rearward and upward is provided on the downward sloping surface extending rearward of the support plate to which the rear of the hood is attached, and the approximately V-shaped space in side view formed by the sloping surface of the support plate and the upper heat-shielding plate piece is configured as a storage area for rainwater that enters through the heat exhaust holes provided in the top plate portion of the spacer cover.

4. 4. The work vehicle according to claim 3, wherein a drain hose is provided at the bottom of the rainwater storage portion, and the rainwater collected in the storage portion is guided to the ground by the drain hose and drained.

5. A work vehicle as described in any one of claims 1 to 4, characterized in that seals are provided at the front and rear ends of the spacer cover, which is formed into a roughly inverted U-shape by the top plate portion and side plate portion where the heat exhaust holes are provided, and these front and rear seals eliminate any gaps that may occur between the rear end of the hood and the front end of the operating section.

6. 6. The work vehicle according to claim 1, wherein a top plate portion of the spacer cover is provided so as to be inclined downward toward the rear.

Images