JP2018069746A - Work vehicle - Google Patents

Abstract

An engine auxiliary device provided in front of an engine is rationally arranged in a space on a radiator bracket, and in particular, a heat exchanger related to the engine, particularly a fuel cooler is reliably cooled effectively. Provide a working vehicle that can
A battery 53 is provided at a front portion of a radiator bracket 40 and a radiator 46 is provided at a rear portion thereof, and an auxiliary equipment mounting stay 40c is provided upright at an intermediate portion between the battery and the radiator. An air cleaner 48 that constitutes engine auxiliary equipment is provided at the upper part of the stay, and air-cooled heat exchangers 38 and 79 are attached below it.
[Selection] Figure 5

Description

  The present invention relates to a work vehicle mainly for agriculture such as a tractor, and more particularly, to a work vehicle in which engine accessories are provided on a radiator bracket provided in front of the engine.

  In order to comply with exhaust gas regulations, diesel engines mounted on work vehicles such as tractors store fuel that has been pressurized with a supply pump in a rail (accumulation chamber) and control each cylinder from the injector in a timely manner under ECU control. A common rail system for injecting an appropriate amount of fuel is adopted, and the fuel is made fine by high fuel injection pressure, thereby reducing unburned fuel and suppressing the generation of PM (particulate matter). In addition, a turbocharger that forcibly feeds high-density air and an air-cooled intercooler are provided to increase engine output, improve fuel efficiency, and reduce CO2 (carbon dioxide) and PM emissions.

Furthermore, an EGR system that recirculates part of the exhaust gas to the engine using an EGR (Exhaust Gas Recirculation) valve, throttle valve, water-cooled EGR cooler that lowers the temperature of the exhaust gas that becomes hot, etc. is adopted. suppress the generation of NO X _(nitrogen oxides) by lowering the combustion temperature. A DOC (diesel oxidation catalyst) is provided that oxidizes HC (hydrocarbon) and CO (carbon monoxide), which are harmful components in the exhaust gas, to water and CO2 to render them harmless.

  By the way, when considering a fuel supply system of a diesel engine that takes such exhaust gas countermeasures, this supply system supplies fuel from a fuel tank to a common rail system via a low pressure pump (feed pump). Further, the surplus fuel of the supply pump that has not been consumed in the common rail system and the surplus fuel of the common rail and the injector merge and are returned to the fuel tank. The fuel returning from the common rail and the injector to the fuel tank passes through the high temperature part of the engine and is very hot.

  When this high temperature surplus fuel is returned to the fuel tank, the temperature of the entire fuel stored in the fuel tank also gradually increases. Furthermore, when high-temperature fuel stored in the fuel tank is supplied to the supply pump, the lubricity of the fuel used for lubrication is lowered, and the supply pump is likely to be worn or seized. In addition, an increase in fuel temperature or a decrease in fuel viscosity may reduce the durability of the low-pressure pump (feed pump) itself that supplies fuel from the fuel tank to the supply pump.

  Therefore, in order to prevent damage to the supply pump or the like, a safety protection function is also provided which automatically saves the output of the engine when the fuel exceeds a certain temperature and lowers the temperature of the fuel. However, in this case, the output of the engine decreases and the engine speed becomes unstable, and there is a risk that work performed at a constant engine speed at all times may be hindered.

  Therefore, in order to solve these problems, the fuel supplied to the supply pump or the like is cooled by various cooling devices or the like. That is, as a cooling device in this case, a radiator (air-cooled fuel cooler) that passes a cooling air of a radiator through a heat exchanger made of an aluminum core integrated with a radiation fin (for example, see Patent Documents 1 and 2), There are known ones that cool fuel using a conduit made of a good material.

Japanese Patent No. 5037297 JP 2010-174854 A

  As described above, in addition to the radiator that lowers the temperature of engine cooling water, the diesel engine includes an air-cooled intercooler and a fuel cooler that cools fuel supplied to a supply pump and the like in order to comply with exhaust gas regulations. These heat exchangers are first provided with a radiator in front of a cooling fan driven by the engine, and further provided with an intercooler or a fuel cooler arranged in a row or in a row so that the heat radiation surface overlaps the front of the radiator. Cools together with the radiator by the suction air of the fan.

  If a heat exchanger such as an intercooler or a fuel cooler is added in addition to the radiator in this way, it is necessary to increase the air volume necessary for cooling these components, and to exchange heat as the cooling load increases. It is necessary to increase the size of the vessel. However, in a working vehicle in which engine auxiliary equipment including a heat exchanger such as a radiator is disposed on a radiator bracket provided in front of the engine and the engine and auxiliary equipment are covered with a bonnet, a space in which the auxiliary equipment is provided. Can not be widened due to various restrictions such as securing the steering angle of the front wheels provided on the left and right and securing the front field of view.

  Therefore, it is required to rationally arrange auxiliary devices in a limited space to increase the cooling efficiency of the heat exchanger in particular. However, as in Patent Document 1, a radiator, a hydraulic oil cooler, a condenser, and a fuel oil cooler are provided in order from the rear to the front on the bottom plate installed on the body frame, and a battery is further provided in front of the hood. When the airflow from the front of the vehicle taken into the front end passes through the battery and flows in sequence to the fuel oil cooler, condenser, hydraulic oil cooler, and radiator, it is obstructed by the battery that is blocked, and the upper side in the vertical direction of each heat exchanger Anyway, the airflow hardly flows from the middle part to the lower part side, and there is a possibility that the heat exchanger having a large size cannot be efficiently cooled.

  Further, as in Patent Document 2, a fuel cooler is disposed in a dead space formed by an air cleaner, a condenser, an oil cooler, and a radiator on the upper surface side of a mounting plate fixed to the body frame, or a fuel cooler. Is placed between the radiator and the oil cooler, even if the fuel cooler is damaged, the fuel can be prevented from falling on the battery or the battery cable, and the upper end of the fuel cooler is more than the upper end of the oil cooler. If it arrange | positions so that it may be located upwards, cold air can be applied to a fuel cooler, without being interrupted by an oil cooler.

  However, if the fuel cooler is provided behind the air cleaner, the air cleaner may be obstructed and cold air may not be applied to the fuel cooler. Also, if the fuel cooler is placed between the radiator and the oil cooler and the upper end of the fuel cooler is positioned above the upper end of the oil cooler, the fuel cooler will not be blocked by the oil cooler as described above. Can be exposed to cold air. However, since the lower end portion of the fuel cooler overlaps with the condenser and the oil cooler in the front-rear direction, the air warmed through the condenser and the oil cooler hits, and the cooling efficiency may not be improved as expected. There is.

  Note that the temperature of the fuel supplied to the engine varies depending on the load state of the engine, the outside air temperature, the remaining amount of fuel stored in the fuel tank, the atmosphere in which the engine is placed, etc., for example, when the remaining amount of fuel decreases, The high-temperature surplus fuel returned to the fuel tank is supplied to the engine as it is, and the temperature of the fuel supplied to the engine becomes high. Also, if the condenser needs to be cooled due to the operation of the air conditioner, the exhaust air temperature after cooling the heat exchanger such as the condenser and radiator will rise, and even if you try to cool the air by applying this exhaust air to the engine with the cooling fan, The temperature of the engine does not drop so much and the temperature of the fuel increases accordingly.

  And as mentioned above, damage to the supply pump caused by the rise in fuel temperature and reduction in engine output due to the activation of the safety protection function to prevent this are one of the most important problems for work vehicles, It is necessary to cool the fuel cooler with priority over the cooling of other heat exchangers.

  Therefore, in view of the above problems, the present invention rationally arranges engine auxiliary equipment including a radiator provided in front of the engine in a space on a limited radiator bracket, and in particular, heat related to the engine. It is an object of the present invention to provide a work vehicle capable of reliably and effectively cooling an exchanger, in particular, a fuel cooler.

  In order to solve the above-described problems, the present invention provides a work vehicle in which engine accessories including a radiator for cooling the engine are disposed on a radiator bracket provided in front of the engine, and the engine and the accessories are covered with a bonnet. In addition, a battery is provided at the front part of the radiator bracket, and a radiator is provided at the rear part, and an auxiliary equipment mounting stay is erected at an intermediate part between the battery and the radiator, and an engine is provided above the auxiliary equipment mounting stay. The air cleaner that constitutes the auxiliary equipment is placed at the top, and an air-cooled heat exchanger is attached below it, so that the heat exchanger can be effectively exchanged heat at a high position avoiding the battery It is characterized by doing.

  Further, the present invention is characterized in that the air-cooled heat exchanger is a fuel cooler for cooling engine fuel.

  Furthermore, the present invention is characterized in that the fuel cooler is a return-side cooler that cools surplus fuel returning from the engine to the fuel tank.

  The present invention is characterized in that the fuel cooler is a return-side cooler that cools surplus fuel returning from the engine to the fuel tank, and a suction-side cooler that cools fuel supplied from the fuel tank to the engine. .

  Moreover, the present invention is characterized in that the suction-side fuel cooler is provided in front of the return-side fuel cooler.

  According to the work vehicle of the present invention, a battery is provided at the front portion of the radiator bracket, and a radiator is provided at the rear portion, and an auxiliary equipment mounting stay is erected at an intermediate portion between the battery and the radiator. At the top of the mounting stay is an air cleaner that constitutes the engine auxiliary equipment, and an air-cooled heat exchanger is attached below it, so that the heat exchanger is effectively heated at a high position avoiding the battery. Because it is configured so that it can be exchanged, the outside air taken in from the bonnet intake is not blocked by the battery provided in the front or the air cleaner provided above, and applied to the air-cooled heat exchanger that constitutes the engine auxiliary equipment. This can be effectively cooled.

  In addition, the auxiliary equipment mounting stay standing in the middle between the battery and the radiator can be used also as the mounting stay for the air cleaner and air-cooled heat exchanger, thus reducing the cost for manufacturing the radiator bracket. You can plan. Moreover, even if the air-cooled heat exchanger is enlarged to ensure the required heat exchange capacity, the work vehicle is shaken during travel because the heat exchanger is attached to a single member called an auxiliary equipment mounting stay. However, the top and bottom or left and right mounting parts of the heat exchanger are less likely to cause a phase difference. Temporarily, the top and bottom or left and right mounting parts of the heat exchanger are attached to separate members, and the heat exchanger is burdened by the phase difference. It is possible to prevent the adverse effect of deforming or damaging the heat exchanger and spreading the medium of the heat exchanger around.

  Furthermore, if the air-cooled heat exchanger is a fuel cooler that cools the fuel of the engine, a common rail system is adopted to comply with exhaust gas regulations, and as a result, high-temperature surplus fuel is returned to the fuel tank. The temperature of the fuel that becomes high overall can be cooled by a fuel cooler and the temperature can be lowered, so that it is possible to prevent damage to the supply pump, etc., and reduction in engine output due to the activation of a safety protection function that prevents this. .

  Moreover, if the fuel cooler is a return-side cooler that cools the surplus fuel that returns from the engine to the fuel tank, the surplus fuel is cooled by the return-side cooler and returned to the fuel tank, so that the fuel tank becomes hot. It is possible to prevent the fuel tank material such as a resin tank from deteriorating due to the fuel temperature.

  In addition, if the fuel cooler is a return-side cooler that cools excess fuel that returns from the engine to the fuel tank, and a suction-side cooler that cools the fuel supplied from the fuel tank to the engine, heat exchange between the return-side fuel cooler Cooling the fuel whose capacity could not be secured due to installation space constraints, etc., and the fuel that was raised in the process of supplying fuel to the engine from the fuel tank by the cooler on the suction side The fuel temperature can be reliably lowered to an allowable value.

  In addition, when the suction-side fuel cooler is provided in front of the return-side fuel cooler, the suction-side fuel cooler can be provided by using an empty space in front of the return-side fuel cooler. In addition, the fuel cooled on the whole by the fuel cooler on the return side and the fuel stored in the fuel tank, the fuel cooler on the suction side only needs to be slightly lowered to an allowable temperature, and therefore the size can be reduced. A suction-side fuel cooler that can perform the above operation is provided in front of the return-side fuel cooler, and the taken-in outside air is applied to the return-side fuel cooler without being blocked by the return-side fuel cooler.

  The return-side fuel cooler is thereby cooled by the air heated by the front suction-side fuel cooler, but the amount of heat released from the suction-side fuel cooler is small, and the suction-side fuel cooler The outside air taken in directly hits the front surface of the non-overlapping return-side fuel cooler and can be cooled, so the influence can be almost ignored.

It is a side view of the tractor of a 1st embodiment. It is explanatory drawing of the fuel supply system of an engine. It is a perspective view of a radiator bracket. It is a perspective view which shows the state which attached the auxiliary device to the radiator bracket. It is a side view which shows the state which attached the auxiliary device to the radiator bracket. It is a perspective view which shows the state which attached the return side fuel cooler to the auxiliary equipment attachment stay. It is a front view which shows the state which attached the return side fuel cooler to the auxiliary equipment attachment stay. It is a perspective view of the attachment bracket of a fuel cooler. It is a side view of the tractor of 2nd Embodiment. It is explanatory drawing of the fuel supply system which added the fuel cooler by the side of suction. It is a perspective view which shows the attachment state of the fuel cooler by the side of suction. It is a side view of 2nd Embodiment which attached the auxiliary device to the radiator bracket. It is a perspective view which shows the attachment state of an oil cooler.

  A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a tractor 1 as a work vehicle integrally connects an engine 2, a clutch housing 3, a transmission case 4 and the like from the front to form a vehicle body (airframe). In addition, a bonnet 5 that covers the engine 2 and the accessories of the engine 2 and left and right side covers 6 are provided on the front side of the vehicle body, and the bonnet 5 can be freely opened and closed through a hinge provided at the rear. The side cover 6 is configured to be detachable from the vehicle body.

  Further, a front axle case is pivotally supported by a front bracket 7 that is fixed to the engine 2 and extends forward so that the front axle case can swing left and right. A front axle case (a kingpin case and a final case) is attached to the left and right ends of the front axle case. Further, the front axle case supports a front axle 9 to which the front wheels 8 are attached, and the left and right front wheels 8 are steered by a steering wheel 10 provided in the control section. On the other hand, a rear axle case connected to the left and right of the transmission case 4 is provided on the rear side of the vehicle body, and left and right rear wheels 12 are attached to a rear axle 11 pivotally supported on the rear axle case.

  A well-known three-point link mechanism including a top link 13 and left and right lower links 14 is provided at the rear part of the vehicle body. This three-point link mechanism connects working machines such as mowers and rotary tillers, and the working machines are the left and right lift arms of the hydraulic housing attached to the upper part of the transmission case 4 and the left and right ends of the left and right lift arms. The lower link 14 is moved up and down via a lift rod having one end connected thereto. Further, engine power is transmitted to the work machine from a PTO shaft (power take-off shaft) pivotally supported on the rear portion of the transmission case 4.

  Furthermore, the floor 15 is attached to the vehicle body behind the engine 2 via a vibration isolator. A steering column 10 is provided on the steering column near the front portion of the floor 15, and a meter panel 16 including an instrument panel and a rear panel cover 17 covering the lower side thereof are provided. Further, a driver's seat 18 is provided on the lower seat cover near the rear of the floor 15, and left and right fenders 19 are provided on the sides of the driver's seat 18. Then, left and right lower struts 20 are provided at the rear of the driver's seat 18, and an inverted U-shaped roll bar 21 is attached to the upper portion of the lower strut 20 to constitute a safety frame.

  In addition, 22 is a sub-step that becomes a stepping board when getting on and off depending on the floor 15, and 23 is a left and right fuel tank attached to the lower part of the floor 15 via a tank bracket 24, and the left and right fuel tanks communicate with fuel. In the right fuel tank 23, a suction hose that sends fuel toward a segmenter 25 (see FIG. 9) that removes water from the fuel, and a return that returns surplus fuel from the engine 2 to the fuel tank 23. Connect the hose. In addition, a fuel supply port 23a is provided in the upper part on the front side of the left fuel tank 23, and 26 is a cap for covering this.

  Various operating tools are provided in the control section around the driver's seat 18. First, a forward / reverse switching lever 27 is provided on the left cover that covers the upper portion of the steering column, and an engine control lever 28 is provided on the right side. A clutch pedal 29 is provided on the left side of the floor 15 near the front, and left and right brake pedals (not shown) are provided on the other side. Further, a position control lever that raises and lowers the working machine between the driver's seat 18 and the right fender 19, and a PTO speed change lever, and a main speed change lever that changes the vehicle speed between the driver's seat 18 and the left fender 19, Provide an auxiliary gearshift lever.

  Next, the engine 2 will be described. The engine 2 uses a diesel engine that uses light oil as fuel. Further, in order to comply with exhaust gas regulations, fuel that has been increased in pressure by the supply pump 30 is stored in the common rail 31 (accumulation chamber), and fuel is injected from the injector 33 into each cylinder under the control of the ECU 32 (electronic control unit). Adopt a common rail system. Further, a turbocharger that forcibly sends high-density air using the flow of exhaust and an intercooler 34 that cools the air pressurized by the turbocharger are provided.

  In addition, an EGR system that recirculates part of the exhaust gas to the engine by an EGR (Exhaust Gas Recirculation) valve, throttle valve, water-cooled EGR cooler that lowers the temperature of exhaust gas that becomes hot, etc. is adopted. A DOC (diesel oxidation catalyst) is provided as a processing apparatus.

  Further, the fuel system for supplying fuel to the engine 2 will be described. As shown in FIG. 2, the fuel stored in the left and right fuel tanks 23 enters the segmenter 25 through the suction hoses, and the water in the fuel is removed. To the pre-filter 35. Here, the pre-filter 35 collects impurities in the fuel. Further, an electromagnetic pump (feed pump) 36 is provided on the downstream side of the pre-filter 35, and the feed pump 36 sends the fuel sucked from the fuel tank 23 to the main filter 37.

  Further, the main filter 37 collects finer impurities in the fuel in the same manner as the pre-filter 35. Further, the fuel supplied to the supply pump 30 becomes high pressure and is sent to the common rail 31, and further, fuel is injected from the common rail 31 to each cylinder through the injector 33. The surplus fuel in the supply pump 30 that has not been consumed in the common rail system and the surplus fuel in the common rail 31 and the injector 33 merge and return to the fuel tank 23 via the return hose.

  However, when the engine 2 is operated, for example, in an environment where the outside air temperature is 35 degrees Celsius, the surplus fuel of the supply pump 30 is about 60 degrees Celsius or less, whereas the common rail 31 passing through the high temperature portion of the engine 2 and The surplus fuel in the injector 33 is about 140 degrees Celsius and is very high temperature. Therefore, before the surplus fuel is returned into the fuel tank 23, the fuel cooler 38 is used to cool the excess fuel to about 60 degrees Celsius or less, and then the fuel is returned to the fuel tank 23.

  The returned surplus fuel is mixed with the fuel in the fuel tank 23, whereby the fuel temperature in the fuel tank 23 becomes about 50 degrees Celsius or less, and this fuel is supplied to the feed pump 36 and the supply pump 30. . Therefore, damage to the feed pump 36, the supply pump 30, and the like due to the high-temperature fuel supply, which is caused by returning the surplus fuel directly to the fuel tank 23, is prevented. In addition, the activation of the safety protection function of the ECU 32 for the purpose of preventing pump damage due to an increase in fuel temperature is suppressed, and a decrease in the output of the engine 2 can be prevented.

  Next, the arrangement of the auxiliary devices of the engine 2 will be described mainly with respect to the mounting and cooling method of the fuel cooler 38. First, the front side of the bonnet 5 that covers the auxiliary devices of the engine 2 will be described. As shown in FIG. 1, a front grill portion 5a is provided, and the front grill portion 5a is provided with ventilation heads 5b and 5c for taking outside air into the bonnet 5 above and below the headlamp unit 39. Further, ventilation openings 5d and 5e are provided on the side surface of the front grill portion 5a near the lower part on the rear side to increase the intake amount of air necessary for cooling the auxiliary equipment of the engine 2. In addition, a net is provided at each of the ventilation openings 5b, 5c, 5d, and 5e to prevent dust from entering.

  And the auxiliary equipment of the engine 2 covered with the bonnet 5 is attached to the radiator bracket 40 fixed on the engine 2 and attached on the front bracket 7 extending forward. That is, as shown in FIG. 3, the radiator bracket 40 is configured by fixing a radiator mounting stay 40b, an auxiliary device mounting stay 40c, a fuel filter mounting stay 40d, and a battery mounting stay 40e to a base 40a serving as a bottom plate.

  More specifically, the radiator mounting stay 40b is provided with a gate-shaped frame frame standing in the left-right direction at the rear end of the base 40a, and the upper bracket 41 and the left and right plates 42 are mounted on the upper and left sides thereof. The outer peripheral edges of the upper bracket 41 and the plate 42 close the inner surface of the bonnet 5 and close the gap between the radiator mounting stay 40b and the bonnet 5, so that the radiator bracket 40 from the engine 2 side is closed. It functions as a partition plate that prevents hot air from blowing back to the side.

  Further, the upper bracket 41 supports the upper portion of the radiator, and the right and left plates 42 are appropriately provided with holes through which auxiliary equipment pipes are passed. Further, fan shrouds 43 and 44 are attached to the rear side of the radiator mounting stay 40b, and a radiator net 45 is detachably attached to the front side from the right side. And the radiator attachment stay 40b comprised in this way attaches and supports the radiator 46 which mainly cools the cooling water of the engine 2 near the rear part.

  And the cooling fan 47 (refer FIG. 12) provided in front of the engine 2 faces the fan shrouds 43 and 44 attached to the rear part of the radiator attachment stay 40b, and is driven by the engine 2 via a belt. Accordingly, the cooling fan 47 sucks air in front of the front surface of the radiator 46 through the main body of the radiator 46, whereby the cooling water of the engine 2 flowing through the radiator 46 is cooled by taking heat away from the sucked air. . The exhaust air discharged from the cooling fan 47 flows from the front surface of the engine 2 to the outer peripheral surface of the main body to cool the engine 2 with air.

  The auxiliary equipment mounting stay 40c is a pipe frame including a leg portion a that rises upward from the right end of the base 40a in front of the radiator mounting stay 40b and an upper portion b that is substantially parallel to the base 40a and bends backward from the left and right directions. Formed by. The rear end of the upper portion b is fixed to the radiator mounting stay 40b, and the auxiliary device mounting stay 40c and the radiator mounting stay 40b are reinforced with each other. Further, an attachment portion S of an air cleaner 48 for purifying the air supplied to the engine 2 is provided in combination with a plurality of plates c on the upper part b of the auxiliary equipment attachment stay 40c.

  Further, the fuel filter mounting stay 40d includes a leg portion d that rises upward from the left end of the base 40a opposite to the leg portion a of the auxiliary device mounting stay 40c, and a mounting portion e provided above the leg portion d. And the upper end of the connecting portion f is fixed to the left end side in the left-right direction of the upper portion b of the auxiliary device mounting stay 40c, whereby the fuel filter mounting stay 40d and the auxiliary device mounting stay are fixed. 40c becomes a mutually reinforced relationship. Further, the battery mounting stay 40e is configured by standing up to four angles g near the front portion of the base 40a.

  And the auxiliary equipment of the engine 2 is attached to the radiator bracket 40 comprised as mentioned above as follows. That is, as shown in FIGS. 4 and 5, the radiator 46 is attached to the radiator mounting stay 40 b of the radiator bracket 40 while supporting the upper, lower, left, and right four places via the cushion as described above. An intercooler 34 is attached to the front portion of the radiator mounting stay 40b, and the intercooler 34 closes the front surface of the radiator 46 so as to overlap.

  An intercooler net 49 is provided in front of the intercooler 34, and the intercooler net 49 is detachably provided at the front part of the left and right plates 50 attached to the left and right front parts of the radiator mounting stay 40b. Further, the air cleaner 48 is mounted and mounted on the mounting portion S provided on the upper portion b of the auxiliary device mounting stay 40c so as to face in the left-right direction. Further, the fuel cooler 38 is attached to the upper part b of the auxiliary equipment mounting stay 40 c so as to be in the left-right direction so as to be below the air cleaner 48.

  More specifically, as shown in FIGS. 6 to 8, the attachment portion on the upper side of the fuel cooler 38 is attached to the attachment portion S to which the air cleaner 48 is attached (the rear side plate of the attachment portion S) with two bolts on the left and right. Further, the left and right upper portions 51a of the fuel cooler mounting bracket 51 are attached to the mounting portion S (left and right side plates of the mounting portion S) with bolts, and the lower mounting portion of the fuel cooler 38 is connected to the fuel cooler mounting bracket 51. Is attached to the lower part 51b of the right and left with two bolts and nuts.

  When the fuel cooler 38 is attached to the upper part b of the auxiliary equipment mounting stay 40c as described above via the mounting portion S and the fuel cooler mounting bracket 51 in a vertically supported state, a single member called the auxiliary equipment mounting stay 40c is formed. Since the fuel cooler 38 (heat exchanger) is firmly attached to the upper portion, even if the tractor 1 is shaken by road surface unevenness or the like during traveling, a phase difference is unlikely to occur in the upper and lower attachment portions of the fuel cooler 38. Attaching the upper and lower or left and right mounting portions of the fuel cooler 38 to separate members, and applying a burden to the fuel cooler 38 due to the phase difference, preventing the harmful effect of deforming or breaking the fuel cooler around it. Can do.

  Further, the prefilter 35 is attached to the fuel filter attachment stay 40d with bolts in an up-and-down direction at an attachment portion e provided on the upper portion of the leg portion d. Further, the mounting plate 52 is attached to the battery mounting stay 40e on the four angles g with bolts, and the battery 53 is attached to the mounting plate 52 with clamps 54, L bolts 55, and nuts.

  A stay is erected on the left end of the mounting plate 52 and a reservoir tank 56 of the radiator 46 is attached. Further, the above-described ECU 32 for controlling the engine 2 is attached to the lower surface of the mounting plate 52, thereby preventing the ECU 32 from being affected by the heat of the engine 2 and being able to come into contact with the outside air taken into the bonnet 5. It arrange | positions in the space between the mounting plates 52, and makes the cooling device of special ECU32 unnecessary. Further, as shown in FIG. 3, an electromagnetic pump 36 is attached to the left lower surface on the front side of the base 40a.

  Then, the tractor 1 configured as described above starts the engine 2 and travels on the road, or reaches the agricultural field and performs a tilling work by, for example, a rotary tiller. In this case, the tractor 1 is a low-speed vehicle and rarely takes outside air into the bonnet 5 by traveling wind like an automobile. However, the traveling wind can still be taken in somewhat from the vents 5b and 5c provided on the front surface side of the bonnet 5.

  On the other hand, the cooling fan 47 of the engine 2 sucks the air on the front side of the front surface of the intercooler 34 and the fuel cooler 38, or its upper, lower, left and right surroundings through the radiator 46, thereby ventilating holes 5b, 5c, 5d provided in the bonnet 5. Outside air is taken into the bonnet 5 from 5e, and each air-cooled heat exchanger (the fuel cooler 38, the intercooler 34, and the radiator 46) is cooled. Further, the air cleaner 48 provided above the battery 53 sucks air taken into the bonnet 5 from its downward intake port 48a.

  Further, the prefilter 35, the reservoir tank 56, the battery 53, and the ECU 32 that constitute the auxiliary devices of the engine 2 are provided on the base 40a serving as the bottom plate of the radiator bracket 409, and are actively applied by the outside air taken into the bonnet 5. If they are higher than the temperature of the taken-in outside air, they are deprived of heat by the outside air and cooled.

  Further, the fuel tank 23 and the segmenter 25 provided on the periphery of the floor 15 and the electromagnetic pump 36 provided on the lower surface of the base 40a serving as the bottom plate of the radiator bracket 40 are disposed away from the engine 2 and cooled by direct contact with the outside air. In the environment. Accordingly, the supply pump 30, the common rail 31, the injector 33, and the main filter 37 that are provided in the engine 2 and driven by the engine 2 are not in an environment where they are cooled by direct contact with the outside air apart from the engine 2, but other engines. As described above, the two auxiliary devices can be air-cooled forcibly or indirectly to sufficiently perform their respective functions.

  Next, a second embodiment of the present invention will be described with reference to FIGS. That is, the tractor 1 as the work vehicle of the second embodiment is a so-called frame vehicle in which the tractor 1 of the first embodiment is provided with a safety frame, whereas the tractor 1 is a cabin vehicle that covers the control unit with the cabin 57. . Hereinafter, the same components described in the first embodiment are denoted by the same reference numerals in the drawings of the second embodiment, and the description thereof may be omitted.

  Here, the cabin 57 that covers the steering section is mounted on the vehicle body behind the engine 2 via vibration-proof rubber. The cabin 57 includes a front pillar 58 as a pair of left and right front pillars, a rear pillar 59 as a pair of left and right rear pillars, a pair of left and right center pillars 60, and six pillars extending in the vertical direction. A cabin frame is constituted by a rectangular frame-shaped roof frame 61 that connects and fixes the upper ends of 58, 59, and 60, and a lower frame 62 that connects and fixes the lower ends of the columns 58, 59, and 60.

  The left and right door glasses 63 are attached to the cabin frame so as to be openable and closable via hinges 64 provided on the rear side, the front glass 65 is provided on the front side, the rear glass 66 is provided on the rear side, and the door glass 63 is provided. A side glass 67 is provided behind. Further, a fender 69 that covers the upper front side of the rear wheel 12 is extended from the lower end portions of the left and right rear pillars 59 toward the floor 68 that is obliquely below the front.

  Further, an inner roof and an outer roof 70 are attached to the roof frame 61, and the air in the cabin 57 is taken in through the suction port between the inner roof and the outer roof 70, and cooled or warmed by an evaporator or a heater core. An air conditioner unit that blows air from the grille is installed. The air conditioner cooler system is composed of a compressor, a condenser 71, a receiver dryer 72, and the air conditioner unit and piping connecting them, among which the compressor compresses the gaseous refrigerant from the evaporator to provide high temperature and high pressure. To the capacitor 71.

  The gaseous refrigerant cooled by the condenser 71 is sent to the receiver dryer 72 while being changed into a liquid refrigerant. The receiver dryer 72 removes dust, moisture, etc. contained in the refrigerant and accumulates the refrigerant, and sends only the accumulated liquid refrigerant to the expansion valve of the air conditioner unit. Furthermore, the expansion valve cools the cabin 57 by exchanging heat with the evaporator in the form of a mist that easily evaporates the refrigerant and sending it to the evaporator.

  Here, although the compressor is attached to the engine 2, the condenser 71 and the receiver dryer 72 are attached to the radiator bracket 40 in front of the engine 2. More specifically, as shown in FIGS. 11 to 13, the capacitor 71 is provided in front of the intercooler 34 so as to overlap the front surface of the intercooler 34, and is fixed to the base 40a of the radiator bracket 40 so as to stand up and down. Attach to.

  The capacitor mounting stay 73 is fixed to the front ends of the left and right plates 74 attached to the radiator mounting stay 40b via a cushioning material 75 to prevent the capacitor 71 from shaking. The receiver dryer 72 is attached to the front part of the capacitor attaching stay 73 on the right side. Further, a capacitor net 76 is provided on the front side of the capacitor 71, and the capacitor net 76 is detachable from the left and right capacitor mounting stays 73.

  On the other hand, the tractor 1 of the second embodiment is provided with an oil cooler 77 that cools hydraulic oil that intermittently lubricates or lubricates a hydraulic clutch or the like of a traveling transmission provided in the mission case 4. The oil cooler 77 is attached to the radiator bracket 40 in front of the engine 2. More specifically, the oil cooler 77 is provided between the condenser 71 and the battery 53 by effectively utilizing an empty space below the fuel cooler 38, and is mounted on the bracket 78 attached to the base 40a of the radiator bracket 40 in the left-right direction. Install so that it becomes.

  The condenser 71 and the oil cooler 77 are cooled by the air sucked by the cooling fan 47 of the engine 2 in the same manner as the other heat exchangers (the fuel cooler 38, the intercooler 34, and the radiator 46). However, the heat radiation amount of the condenser 71 is particularly large, and accordingly, the exhaust air temperature discharged from the cooling fan 47 becomes high. For this reason, the temperature of the engine 2 that is air-cooled by this exhaust air also increases, the temperature of the surplus fuel discharged from the common rail 31 and the injector 33 of the engine 2 also rises, and the fuel cooler 38 provided on the return side alone increases the temperature of the fuel. It may not be able to be lowered.

  Therefore, in the second embodiment, as shown in FIG. 10, a second fuel cooler 79 is provided on the suction side for supplying fuel from the fuel tank 23 to the supply pump 30 and the like, and the fuel temperature is set to Celsius by the fuel cooler 79. The temperature is lowered to about 50 degrees or less to prevent damage to the electromagnetic pump 36, the supply pump 30, and the like. The second fuel cooler 79 is provided in a flow path between the prefilter 35 and the electromagnetic pump 36, and water in the fuel is removed by the segmenter 25, and impurities are removed to some extent by the prefilter 35. Cool the fuel.

  Further, the suction-side fuel cooler 79 is provided in front of the front surface of the return-side fuel cooler 38 as shown in FIGS. 11 to 13, so that it can be easily removed and attached as necessary. To. More specifically, the fuel cooler mounting bracket 51 for mounting the lower side of the fuel cooler 38 on the return side includes left and right upper mounting portions 51a mounted on the mounting portion S of the auxiliary device mounting stay 40c, as shown in FIG. A lower attachment portion 51b for attaching the lower side of 38 is provided, and a second fuel cooler attachment portion 51c is provided in advance between the upper attachment portion 51a and the lower attachment portion 51b.

  The second fuel cooler mounting portion 51c is provided with left and right bolts 51d that are forwardly fixed, and the left and right bolts 51d are mounted with mounting portions provided at the lower portion of the second fuel cooler 79 so as to be nuts. Screw on and attach. Therefore, the second fuel cooler 79 can be attached also as the bracket 51 of the return-side fuel cooler 38 to reduce the cost.

  In addition, the second intake-side fuel cooler 79 only needs to slightly lower the fuel cooled down by the fuel stored in the return-side fuel cooler 38 and the fuel tank 23 to an allowable temperature. Along with this, the intake-side fuel cooler 79 may be a small one with less heat dissipation than the return-side fuel cooler 38, so that it is provided in front of the return-side fuel cooler 38 to return the taken-in air (outside air). It is possible to effectively cool it by applying it first without being blocked by the side fuel cooler 38.

  In the embodiment described above, the entire surplus fuel returned from the engine 2 to the fuel tank 23 is cooled by the fuel cooler 38 on the return side, but only the surplus fuel in the common rail 31 and the injector 33 that become high temperature is returned to the fuel on the return side. The cooler 38 may be used for cooling, or only the surplus fuel in the common rail 31 and the injector 33 that are at a high temperature is cooled by the fuel cooler 38 on the return side, and this is returned to the suction side of the supply pump 30 and the electromagnetic pump 36. Also good.

  Furthermore, a suction-side fuel cooler 79 may be provided in the flow path between the main filter 37 and the supply pump 30. Alternatively, the fuel coolers 38 and 79 are attached to the auxiliary equipment mounting stay 40c as air-cooled heat exchangers, but an oil cooler 77 may be attached instead of this, and the present invention is limited to the above-described embodiment. is not.

1 Tractor (work vehicle)
2 Engine 5 Bonnet 23 Fuel tank 38 Return-side fuel cooler (air-cooled heat exchanger)
40 Radiator bracket 40c Auxiliary device mounting stay 46 Radiator 48 Air cleaner 53 Battery 79 Suction side fuel cooler (air-cooled heat exchanger)

Claims (5)

  An engine auxiliary device including a radiator for cooling the engine is disposed on a radiator bracket provided in front of the engine, and in a work vehicle in which the engine and the auxiliary device are covered with a bonnet, a battery is provided at a front portion of the radiator bracket. In addition, a radiator is provided at the rear, and an auxiliary equipment mounting stay is erected at an intermediate portion between the battery and the radiator, and an air cleaner that constitutes engine auxiliary equipment is provided above the auxiliary equipment mounting stay. A work vehicle characterized in that an air-cooled heat exchanger is attached below the heat exchanger so that the heat exchanger can effectively exchange heat at a high position avoiding the battery.   The work vehicle according to claim 1, wherein the air-cooled heat exchanger is a fuel cooler that cools engine fuel.   The work vehicle according to claim 2, wherein the fuel cooler is a cooler on a return side that cools surplus fuel returning from the engine to the fuel tank.   The said fuel cooler is made into the cooler of the return side which cools the surplus fuel which returns from an engine to a fuel tank, and the cooler of the suction side which cools the fuel supplied to an engine from a fuel tank, The Claim 2 characterized by the above-mentioned. Work vehicle.   The work vehicle according to claim 4, wherein the suction-side fuel cooler is provided in front of the return-side fuel cooler.