Work vehicle

Abstract

To provide a work vehicle which includes a heat exchanger cooling structure which efficiently cools, and which can improve cooling performance by the heat exchanger without providing a new structure or lowering the freedom degree of design in the heat exchanger such as an oil cooler and a condenser.SOLUTION: In a cooling air duct 10, an oil cooler 28 is arranged in which a heat exchange part 28a is inclined with respect to a duct shaft center 31 of the cooling air duct 10, and at a machine outside end part 10a of the cooling air duct 10, an end part suction port 10a1 is provided in which an opening surface 10a2 is substantially orthogonal to the duct shaft center 31.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a work vehicle that includes a body on which a work implement is mounted, a prime mover, and a cooling air duct that guides outside air as cooling air toward the prime mover. More specifically, the present invention relates to a heat exchanger cooling structure that can efficiently cool heat exchangers such as oil coolers and condensers without adding a new structure or reducing design freedom, thereby improving the cooling performance of the heat exchanger. [Background technology]

[0002] Conventionally, in working machines such as backhoes, a technique has been known in which a plurality of cover bodies that cover the mounted components form an air passage that supplies outside air from an intake port as cooling air to the radiator of the prime mover, and an oil cooler that cools the working oil of hydraulic equipment and a condenser that cools the refrigerant of an air conditioning unit are arranged in a row within this air passage, and the cooling air to the radiator is used to cool these heat exchangers, thereby promoting cooling of the heat exchangers (see, for example, Patent Document 1).

[0003] Furthermore, in an onion harvester consisting of a work vehicle fitted with working machines such as a digging device and a lifting and transporting device, a technology is known in which an outside air intake duct is placed in the space below the step of the operating section, and fresh cooling air from outside is supplied through this outside air intake duct to the engine radiator from the intake port, thereby promoting radiator cooling (see, for example, Patent Document 2).

[0004] Additionally, in construction machinery in which the exterior body covering the prime mover has a curved surface, and this curved surface is provided with a vent for supplying and exhausting cooling air, and the prime mover is provided with a cooling fan for supplying and exhausting cooling air, a technology is known in which the cooling core (hereinafter referred to as the "heat exchanger"), which is the part that cools the cooling medium or hydraulic oil in a heat exchanger such as a radiator, is tilted toward the fan axis of the cooling fan and positioned along the curved surface of the exterior body, thereby increasing the size of the heat exchanger and improving the cooling performance of the heat exchanger, or by bringing the heat exchanger close to the vent, improving the workability of maintenance work on the heat exchanger (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-20058 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-45820 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-225625 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the heat exchanger cooling structures described in Patent Documents 1 and 2, when a heat exchanger such as an oil cooler or condenser is housed in the outside air intake duct located in the space below the step of the control section, the size of the space is limited by the control section, and the cross-sectional area of ​​the outside air intake duct that can be placed in this space is also small.As a result, even if a heat exchanger such as an oil cooler or condenser is housed in the outside air intake duct and the cooling air for the engine radiator is effectively used to cool the heat exchanger, the area of ​​the heat exchanger's heat exchange section becomes smaller than usual, resulting in a problem of reduced cooling performance by the heat exchanger.

[0007] Furthermore, in the heat exchanger cooling structure described in Patent Document 3, the heat exchange section of the heat exchanger is arranged along the curved surface of the exterior body, which makes it inevitable to increase the area of ​​the vent and limits the placement position of the vent. This necessitates new structures to prevent dust from entering through the large vent and to compensate for the loss of rigidity of the outside air intake duct due to the increased opening area, while reducing design freedom and increasing the number of parts, leading to higher manufacturing costs and reduced maintainability.

[0008] The present invention has been devised in consideration of the above points, and aims to provide a work vehicle equipped with a heat exchanger cooling structure that can efficiently cool heat exchangers such as oil coolers and condensers without requiring the addition of a new structure or reducing design freedom, thereby improving the cooling performance of the heat exchanger. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a work vehicle equipped with a prime mover and a cooling air duct that guides outside air as cooling air toward the prime mover, wherein a heat exchanger is disposed in the cooling air duct with a heat exchange portion that is inclined with respect to the duct axis of the cooling air duct, and an end inlet is provided at the outboard end of the cooling air duct with an opening surface that is approximately perpendicular to the duct axis. Note that "approximately perpendicular" includes the case where the opening surface is perpendicular.

[0010] Furthermore, when a heat exchanger such as an oil cooler is housed within the cooling air duct and the cooling air to the engine's radiator is to be effectively used to cool this heat exchanger, by arranging a heat exchanger in the cooling air duct with its heat exchange section inclined relative to the duct axis of the cooling air duct, it becomes possible to form a heat exchange section in the heat exchanger that is larger than the cross-sectional area of ​​the cooling air duct, thereby efficiently cooling the heat exchanger and reliably improving the cooling performance of the heat exchanger.

[0011] Furthermore, by locating the heat exchanger inside the cooling air duct as described above and providing an end inlet at the outboard end of the cooling air duct, with its opening surface approximately perpendicular to the duct axis, the area of ​​the end inlet is kept to a minimum, eliminating the need for new structures to prevent dust from entering or to enhance the rigidity of the cooling air duct. The end inlet can also be located away from the heat exchanger, increasing design flexibility, thereby reducing manufacturing costs and improving maintainability.

[0012] In addition, in the present invention, an intermediate intake port facing the heat exchange portion is provided in the intermediate portion of the side wall of the cooling air duct.

[0013] In this case, fresh cooling air from outside is supplied to the heat exchanger from two locations: the end inlet and the mid-way inlet, increasing the total volume of cooling air and improving the cooling efficiency of the heat exchanger, thereby further improving the cooling performance of the heat exchanger.

[0014] Furthermore, even if dust accumulates at either the end suction port or the intermediate suction port, causing it to become clogged and stop functioning, the pressure inside the cooling air duct is reduced, increasing the amount of cooling air coming from the other suction port, compensating for the air volume and minimizing the decrease in the cooling efficiency of the heat exchanger.

[0015] In addition, by providing an intake port midway, the distance to the heat exchanger can be shortened to less than the cross-sectional size of the cooling air duct, making it easier to access the heat exchanger and improving the workability of maintenance work such as inspecting, cleaning, and washing the heat exchanger.

[0016] In particular, if this mid-way intake port is provided on the lower side wall of the cooling air duct, when the engine is stopped after work is completed, the cooling fan that was being driven by the engine to suck air will stop, the negative pressure inside the cooling air duct will be released, and dust that has adhered to the mid-way intake port, dust filter, etc. will automatically fall and be removed, further improving the workability of maintenance work.

[0017] In addition, the present invention is such that at least one of the end suction port and the intermediate suction port is provided with an air volume adjusting section for adjusting the volume of outside air taken in.

[0018] In this case, even if the wind speed at the end inlet and the wind speed at the middle inlet differ greatly, the air volume adjustment unit balances the wind speeds at both inlets. This eliminates the problem of dust concentrating and clogging the inlet with the faster wind speed, which reduces the total opening area of ​​the inlets and increases the wind speed at the inlet with the slower wind speed, causing it to become clogged and blocking both inlets. This allows a stable volume of cooling air to be supplied to the heat exchanger, increasing the cooling efficiency of the heat exchanger and further improving the cooling performance of the heat exchanger.

[0019] In addition, in the present invention, the air volume adjustment section has an air volume restricting body in which a plurality of openings are formed.

[0020] In this case, the amount of outside air taken in through the intake port can be adjusted simply by changing the shape, size, number, and position of the opening formed in the air flow restrictor, allowing the air flow adjustment unit to be formed with a simple configuration, reducing the cost and number of parts and enabling a reduction in manufacturing costs.

[0021] The present invention also includes a separating and rectifying device that divides the air passage from the end suction port to the motor into a first air passage that communicates from the end suction port to the heat exchanger, and a second air passage that communicates directly from the end suction port to the motor.

[0022] In this case, the cooling air from the end intake port is separated into a first cooling air that passes through a first air passage and is supplied to a heat exchanger such as an oil cooler or condenser, and a second cooling air that passes through a second air passage and is supplied directly to a radiator near the engine, so that the first cooling air and the second cooling air do not interfere with each other and maintain constant wind direction and volume.

[0023] As a result, the heat exchanger located midway through the air path acts as a resistor to the cooling air flowing within a single air path, causing the entire cooling air to become turbulent and resulting in large fluctuations in air direction and volume, whereas both the first cooling air and the second cooling air are in a laminar flow state, resulting in more stable air direction and volume, thereby increasing the cooling efficiency of the heat exchanger and further improving the cooling performance of the heat exchanger.

[0024] In addition, the present invention provides a flow rectifier in which the separating and rectifying unit has a flow rectifier that extends parallel to the duct axis from near the side of the heat exchange unit toward the side wall of the cooling air duct, and a gap is provided on the end inlet side of the flow rectifier to partially communicate between the first air path and the second air path.

[0025] In this case, the straightening vane is parallel to the duct axis and acts as almost no resistance to the cooling air flowing through the air duct, so cooling air can be supplied to both the first air duct and the second air duct with a stable direction and volume without becoming turbulent.

[0026] Furthermore, the first air passage is provided on one side of the rectifying plate, and the second air passage is provided on the other side, so that a separated rectifying device can be formed with a simple configuration, and the cost and number of parts can be reduced, thereby reducing manufacturing costs.

[0027] In addition, the first cooling air that flows through the first air passage and collides with the heat exchange section can easily merge with the second cooling air flowing through the second air passage through the gap on the end inlet side of the straightening plate, allowing the first cooling air to be quickly discharged without stagnating near the heat exchange section, and cooling air to be continuously supplied to the heat exchanger, thereby increasing the cooling efficiency of the heat exchanger and further improving the cooling performance of the heat exchanger.

[0028] The present invention also includes a maintenance structure that allows access to the inside of the cooling air duct through the mid-way intake port.

[0029] In this case, the maintenance structure makes it easy to perform maintenance via an intermediate intake port close to the heat exchanger, improving the ease of maintenance work such as inspecting, cleaning, and washing the air volume adjustment unit and heat exchanger.

[0030] In addition, in the present invention, the maintenance structure has a detachable structure for detachably covering the air volume adjusting portion at the midway air inlet.

[0031] In this case, the detachable structure consisting of fasteners etc. allows the air volume adjustment unit to be detached quickly and easily at the start and end of maintenance work, further improving the workability of maintenance work such as inspecting, cleaning and washing the air volume adjustment unit and heat exchanger.

[0032] In addition, the present invention provides a maintenance structure having a rotating part that rotates one side part of the heat exchanger located near the mid-way suction port around the other side part that is farther from the mid-way suction port than the one side part, thereby moving the one side part away from the mid-way suction port to open the mid-way suction port, and a locking part that locks the one side part to maintain the open state.

[0033] In this case, one side of the heat exchanger can be rotated around the other side and locked, allowing the suction port to be left open midway, making it possible to form a maintenance structure with a simple configuration, reducing the cost and number of parts and thereby reducing manufacturing costs. [Effects of the Invention]

[0034] According to the present invention, in a work vehicle that has a frame on which a work implement is mounted, which includes a prime mover and a cooling air duct that directs outside air as cooling air toward the prime mover, it is possible to provide a heat exchanger cooling structure that can efficiently cool heat exchangers such as oil coolers and condensers without providing a new structure or reducing design freedom, and that can improve the cooling performance of the heat exchanger. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a right side view showing the overall configuration of an onion harvester equipped with a work vehicle according to the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] This is also a rear view. [Figure 6] FIG. [Figure 7] These are explanatory diagrams of an air volume adjustment section using a circular hole, where Figure 7(a) is an oblique view of an air volume restriction body with a circular hole formed therein, Figure 7(b) is an oblique view of a cooling air duct with the air volume restriction body attached, and Figure 7(c) is a bottom view of the same. [Figure 8]These are explanatory diagrams of an air flow adjustment section using slit-shaped holes, where Figure 8(a) is an oblique view of an air flow restriction body with slit-shaped holes formed therein, Figure 8(b) is an oblique view of a cooling air duct with the air flow restriction body attached, and Figure 8(c) is a bottom view of the same. [Figure 9] FIG. 10 is a perspective view of a cooling air duct with an inlet in an open state. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, an embodiment of the present invention relating to a work vehicle will be described with reference to the drawings to facilitate understanding of the present invention. The direction indicated by arrow F in FIG. 1 is the front of the work vehicle 1 according to the present invention, and the positions and directions of the various members described below are all based on this forward direction F.

[0037] First, the overall configuration of an onion harvester 3, which is an example of agricultural machinery in which a work implement 2 consisting of a plurality of work devices is attached to the body 1a of a work vehicle 1 to which the present invention is applied, will be described with reference to Figures 1 to 3.

[0038] This onion harvester 3 is equipped with a work vehicle 1 having a crawler-type traveling device 4, which is a self-propelled traveling device, extending in the fore-and-aft direction at the bottom, and a work machine 2 having multiple work devices connected in series from the front F to the rear of the body 1a of this work vehicle 1.

[0039] In the work vehicle 1, an engine 6, which is the prime mover that mainly drives the crawler-type traveling device 4 and the work machine 2, is mounted at the front of the running machine base 5 of the body 1a, and to the right R of this engine 6, on the extension portion 5a extending from the running machine base 5, a cabin 8 is mounted. The cabin 8 has an operating section 7 inside where an operator sits in the driver's seat 7a and performs driving and work operations.

[0040] A cooling air duct 10 with an outboard end 10a open to the outside is located in the space below the step 9 of the control section 7. The end suction port 10a1 of the outboard end 10a is covered by a rotary screen 29 that rotates to remove dust from the suction surface.

[0041] Furthermore, near the engine 6, a fuel tank 45 for the engine 6 is installed on the left, and a radiator 11 for air-cooling the cooling water for the engine 6 is installed upright on the right R, and the inboard end 10b of the cooling air duct 10 is connected to the lower half of this radiator 11.

[0042] In addition, a cooling fan 12 is interposed between the radiator 11 and the engine 6, and is rotated by the engine to draw outside air into the engine 6.

[0043] As a result, when the engine 6 is driven by fuel from the fuel tank 45, the cooling fan 12 rotates in the suction direction, and outside air, from which dust has been removed by the rotary screen 29, is sucked in as fresh cooling air from the end inlet 10a1 at the outboard end 10a. This cooling air is then supplied to the lower half of the radiator 11 near the engine 6 via the cooling air duct 10, thereby efficiently cooling the radiator 11.

[0044] In addition, in the work machine 2, from the front F of the engine 6 to the upper U, there are provided a digging device 13 having approximately the same width as the machine body 1a, and a lifting and conveying device 15 for lifting up the onions dug up by this digging device 13, and a scraping device 14 is interposed between the digging device 13 and the lifting and conveying device 15.

[0045] From above U to the rear of the engine 6, a sorting and conveying device 16 is provided which takes over the onions lifted by the lifting and conveying device 15 and conveys them rearward, and sorts the onions by size during this conveying process.

[0046] At the start of the sorting and conveying device 16, pebbles and small onions being conveyed leak down the trough 17 and fall into the front receiving box 18, and at the midpoint of the conveying process, defective onions are picked up by an operator standing on a work step 21 that protrudes outward from the traveling machine base 5 and dropped from the trough 19 into the rear receiving box 20.

[0047] At the end of the sorting and conveying device 16, onions that fall are larger than the standard size and fall into a container 25 placed on a fork 24 that can be raised and lowered, and are stored therein.

[0048] As a result, onions dug up at the front F of the machine body 1a are sorted by size and quality during transportation after being lifted up, and are stored in storage areas such as receiving boxes 18, 20, and containers 25, allowing the work from digging up the onions to sorting and storing them to be carried out reliably and quickly.

[0049] In addition, in the work machine 2, the aforementioned digging device 13, scraping device 14, and lifting and transporting device 15 are raised and lowered by hydraulic cylinders 26, and further, of these, the digging device 13 and scraping device 14 can be tilted in addition to being raised and lowered by hydraulic cylinders 27, allowing their height above the ground to be adjusted.

[0050] The fork 24 can be raised and lowered by a hydraulic cylinder 22 and a lifting guide 23 protruding from the rear end of the traveling machine base 5.

[0051] These hydraulic devices such as the hydraulic cylinders 22, 26, and 27 in the work machine 2 are driven by hydraulic oil supplied under pressure by a hydraulic pump (not shown) driven by the engine 6 in the work vehicle 1.

[0052] The hydraulic oil used to drive these hydraulic devices is stored in a hydraulic oil tank (not shown), and the hydraulic oil in this hydraulic oil tank is cooled by an oil cooler 28, which will be described in detail later.

[0053] This allows the hydraulic oil to be kept at an appropriate oil temperature, preventing problems that occur as the oil temperature rises, such as a decrease in the dynamic viscosity of the hydraulic oil, which can result in a deterioration in power transmission performance such as operating accuracy and responsiveness, a shortened service life due to deterioration caused by oxidation, hardening of the oil seal due to high temperatures and resulting in oil leakage, and a decrease in lubricity which can lead to wear and seizure.

[0054] With the above-mentioned configuration, in the work vehicle 1, the body 1a to which the work implement 2 is attached is equipped with an engine 6 as a prime mover and a cooling air duct 10 that directs outside air as cooling air toward a radiator 11 near the engine 6.When an operator sits in the driver's seat 7a in the cabin 8 and starts the engine 6, power is transmitted to the crawler-type traveling device 4, causing it to become driven, and the onion harvester 3 begins to travel.At the same time, power is also transmitted to and driven by the digging device 13, raking device 14, lifting and transporting device 15, and sorting and transporting device 16 that make up the work implement 2, causing work from digging up the onions to sorting and storing them to begin.

[0055] At the same time, hydraulic cylinders 22, 26, 27 are extended and retracted by hydraulic oil from the engine-driven hydraulic pump, and each device 13, 14, 15 of the work machine 2 is set to the appropriate height and inclination, thereby carrying out onion harvesting work.

[0056] Next, the arrangement of the oil cooler 28, which is a heat exchanger that cools the hydraulic oil, will be described with reference to FIGS.

[0057] The oil cooler 28 is housed in the cooling air duct 10 described above. Here, the cooling air duct 10 is a rectangular tube in cross section with an axis (hereinafter referred to as the "duct axis") 31 passing through the center of its cross section in the left-right direction, and is composed of an outer peripheral wall 30 consisting of upper and lower side walls 30a and 30b and front and rear side walls 30c and 30d, and an air passage 32 through which outside air passes is formed within the space surrounded by this outer peripheral wall 30.

[0058] An inboard end portion 10b is provided at the left end of this outer peripheral wall 30, while an outboard end portion 10a is provided at the right end of the outer peripheral wall 30. As described above, outside air is drawn in through the end inlet 10a1 of the outboard end portion 10a, passes through the air passage 32, and flows into the lower half of the radiator 11 through the end outlet 10b1 of the inboard end portion 10b, thereby air-cooling the cooling water of the engine 6.

[0059] Of these, the end suction port 10a1 is formed so that its opening surface 10a2 is approximately perpendicular to the aforementioned duct axis 31, and as shown in Figure 5, the area of ​​the end suction port 10a1 can be set smaller than in the case of the opening surface 10a3 which is inclined with respect to the duct axis 31.

[0060] An oil cooler 28 is disposed within the cooling air duct 10 having such a configuration.

[0061] The oil cooler 28 is, for example, a structure in which multiple plates are stacked, with multiple narrow oil passages through which hydraulic oil flows formed between the gaps, and heat dissipation fins interposed between the plates where no multiple oil passages are formed. Of course, this structure is only one example, and the present invention is not necessarily limited to this.

[0062] Of these plates, the exposed part of the outermost shell is the heat exchange section 28a, and when the low-temperature outside air that has passed through the air passage 32 in the cooling air duct 10 as described above collides with this heat exchange section 28a, the working oil in the oil passage is air-cooled via the heat dissipation fins, and heat exchange takes place.

[0063] Furthermore, the aforementioned multiple oil passages are connected to each other to form a single communication passage, one end of which is connected to an oil supply hose 33 and the other end to a drain hose 34, with both hoses 33, 34 extending from the front side surface 28d of the oil cooler 28 and connected to the aforementioned hydraulic oil tank.

[0064] As a result, hydraulic oil that has been used in hydraulic equipment such as the hydraulic cylinders 22, 26, and 27 and has become hot is stored in the hydraulic oil tank, and then supplied to the oil cooler 28 through the oil supply hose 33 and air-cooled.The oil is then returned to the hydraulic oil tank again through the drain hose 34, thereby restoring the temperature of the hydraulic oil in the hydraulic oil tank to normal.

[0065] The oil cooler 28 is held by being inserted from above U into a holding frame 35 that is rectangular in plan view.

[0066] Here, below the upper wall 30a of the cooling air duct 10, a stay base 36a of a U-shaped pivot support stay 36 that opens downward when viewed from the right side is provided extending in the front-to-rear direction, and this stay base 36a is fastened and fixed to the underside of the upper wall 30a by front and rear bolts 38, 38.

[0067] Hanging portions 36b and 36c hang down from the front and rear ends of stay base 36a, and outer end 35a of holding frame 35 is rotatably supported between hanging portions 36b and 36c.

[0068] The oil cooler 28 inserted into such a holding frame 35 is allowed to rotate around the outer part 28b of the oil cooler 28 that is closer to the end inlet 10a1 of the cooling air duct 10, thereby forming a rotating part 39.

[0069] On the other hand, a fixing stay 37 that is L-shaped when viewed from the right side is fixed to the rear edge corner of the lower wall 30b of the cooling air duct 10.

[0070] The lower retaining portion 40 is formed by fastening the inner portion 28c of the oil cooler 28, which is farther away from the end suction port 10a1 than the aforementioned outer portion 28b, to the stay portion 37a protruding forward F from this fixed stay 37 in a detachable manner using a bolt 41.

[0071] As a result, the inner part 28c of the oil cooler 28 can be rotated counterclockwise 42 in rear view around its outer part 28b by the rotating part 39 provided on the upper wall 30a of the cooling air duct 10, and then fastened to the lower engaging part 40 provided on the lower wall 30b of the cooling air duct 10, so that the oil cooler 28 can be set in an inclined position diagonally outward and upward.

[0072] As a result, the heat exchange section 28a of the oil cooler 28 is also inclined at a predetermined angle relative to the duct axis 31, so that the area of ​​the heat exchange section 28a can be increased and the heat dissipation area can be expanded compared to when the heat exchange section 28a is approximately perpendicular to the duct axis 31.

[0073] That is, in a work vehicle 1 equipped with an engine 6 as a prime mover and a cooling air duct 10 that guides outside air as cooling air toward the engine 6 on a machine body 1a on which a work implement 2 is mounted, an oil cooler 28 that is a heat exchanger in which a heat exchange section 28a is inclined with respect to a duct axis 31 of the cooling air duct 10 is disposed in the cooling air duct 10, and an end suction port 10a1 whose opening surface 10a2 is substantially perpendicular to the duct axis 31 is provided at an end 10a of the cooling air duct 10 outside the machine, so that an oil cooler is disposed in the cooling air duct 10 When accommodating a heat exchanger such as oil cooler 28 and effectively utilizing the cooling air to radiator 11 of engine 6 to cool this heat exchanger, by arranging oil cooler 28 in cooling air duct 10 so that heat exchange section 28a is inclined with respect to duct axis 31 of cooling air duct 10, it becomes possible to form heat exchange section 28a in oil cooler 28 that is larger than the cross-sectional area of ​​cooling air duct 10, thereby efficiently cooling oil cooler 28 and reliably improving the cooling performance of oil cooler 28.

[0074] Furthermore, by arranging the oil cooler 28 inside the cooling air duct 10 as described above and providing the end suction port 10a1, whose opening surface 10a2 is approximately perpendicular to the duct axis 31, at the outboard end 10a of the cooling air duct 10, the area expansion of this end suction port 10a1 is kept to a minimum, eliminating the need for a new structure to prevent dust from entering or to supplement the rigidity of the cooling air duct 10, and also allowing the end suction port 10a1 to be located at a distance from the oil cooler 28, increasing design freedom. This makes it possible to reduce manufacturing costs and improve maintainability.

[0075] Next, the structure of the cooling air duct 10 will be described with reference to FIGS.

[0076] As shown in FIGS. 4 to 6, a lower wall 30b of the outer peripheral wall 30 that constitutes the cooling air duct 10 has an intermediate intake port 30e opened at a midpoint in the left-right direction.

[0077] The intermediate suction port 30e has a rectangular shape in a plan view, is opened below and faces the heat exchange portion 28a of the oil cooler 28, and is covered with a dust removal screen 43.

[0078] This dust removal screen 43 is formed by a frame body 43a that is detachably fastened to the underside of the edge of the suction port 30e midway with multiple bolts 46, and a microporous filter body 43b that covers a window portion 43a1 within this frame body 43a.

[0079] As a result, in addition to the cooling air drawn in from the aforementioned end inlet 10a1, cooling air is also drawn in from the intermediate inlet 30e, increasing the total volume of cooling air. Even if one of the screens 29 and 43 becomes clogged with dust, the pressure inside the cooling air duct 10 is reduced, increasing the volume of air from the other inlet.

[0080] Furthermore, the distance from the intermediate suction port 30e to the heat exchanger 28a can be set shorter than the distance from the end suction port 10a1.

[0081] In addition, if the intermediate suction port 30e is formed in the lower wall 30b in this way, as soon as the engine 6 stops, dust adhering to the lower surface of the dust screen 43 and the like automatically falls down by its own weight.

[0082] In other words, if an intermediate intake port 30e facing the heat exchange section 28a is provided in the intermediate portion of the lower wall 30b, which is the side wall of the cooling air duct 10, fresh cooling air from outside will be supplied to the oil cooler 28, which is a heat exchanger, from two locations, the end intake port 10a1 and the intermediate intake port 30e, thereby increasing the total volume of cooling air and improving the cooling efficiency of the oil cooler 28, thereby further improving the cooling performance of the oil cooler 28.

[0083] Furthermore, even if dust accumulates at either the end suction port 10a1 or the intermediate suction port 30e, causing clogging and making it unable to function, the pressure inside the cooling air duct 10 is reduced, increasing the amount of cooling air from the other suction port, thereby compensating for the air volume and minimizing the decrease in the cooling efficiency of the oil cooler 28.

[0084] In addition, by providing an intake port 30e midway, the distance to the oil cooler 28 can be shortened to less than the cross-sectional size of the cooling air duct 10, making it easier to access the oil cooler 28 and improving the workability of maintenance work such as inspection, cleaning, and washing of the oil cooler 28.

[0085] In particular, if this intermediate intake port 30e is provided on the lower wall 30b, which is the lower side wall of the cooling air duct 10, when the engine 6, which is the prime mover, is stopped after work is completed, the cooling fan 12, which was drawing air by engine drive, stops, the negative pressure inside the cooling air duct 10 is released, and dust that has adhered to the intermediate intake port 30e and the dust removal screen 43, which is a dust filter, etc., automatically falls and is removed, further improving the workability of maintenance work.

[0086] As shown in FIGS. 6 and 7, an air flow restrictor 44 is provided on a frame 43a of a dustproof screen 43 that covers the midway air inlet 30e.

[0087] This air flow restricting body 44 is composed of an upper plate portion 44a that is rectangular in plan view and four side plate portions 44b that hang down from the four sides of this upper plate portion 44a, and fixed stays 44b1, 44b1 extend horizontally from the lower ends of the left and right side plate portions 44b, 44b.

[0088] The left and right fixing stays 44b1 are provided with a plurality of bolt holes, and the frame 43a of the dust screen 43 is also provided with bolt holes (not shown).

[0089] As a result, the bolt holes of the fixing stays 44b1·44b1 are aligned with the bolt holes of the frame body 43a, and the fixing stays 44b1·44b1 are fastened to the frame body 43a with a plurality of bolts 47, so that the air flow restricting body 44 is removably attached to the upper surface of the dust screen 43.

[0090] Furthermore, the upper plate portion 44a has a large number of holes 44a1 that are circular in plan view, and the cooling air sucked in from the intake port 30e along the way is supplied to the heat exchange section 28a of the oil cooler 28 only through these holes 44a1.

[0091] As a result, an air volume adjusting section 50 is formed by such an air volume restricting body 44 and a dust removal screen 43, etc., which can easily and freely change the volume of cooling air supplied to the heat exchange section 28a simply by changing the shape, size, number, position, etc. of these holes 44a1.

[0092] As shown in FIG. 8, the air flow restrictor 49 may be configured similarly to the air flow restrictor 44 by being composed of an upper plate 49a and four side plate portions 49b, with a slit-shaped hole 49a1 formed in the upper plate portion 49a in a planar view, and the size, number, position, etc. of the hole, including its shape, are determined by the appropriate air volume of cooling air required for the oil cooler 28 and the relationship with the amount of outside air drawn in from the end inlet 10a1 and the intermediate inlet 30e, and are not particularly limited.

[0093] That is, if at least one of end suction port 10a1 and mid-suction port 30e is provided with airflow adjusters 50 and 51 that adjust the amount of outside air taken in, even if the air speed at end suction port 10a1 and the air speed at mid-suction port 30e differ greatly, the airflow speeds at both suction ports 10a1 and 30e are balanced by airflow adjusters 50 and 51. This eliminates the problem of dust concentrating and clogging the suction port with the faster airflow speed, which in turn reduces the total opening area of ​​suction ports 10a1 and 30e, causing the suction port with the slower airflow speed to also increase and become clogged, resulting in the blockage of both suction ports. This allows a stable volume of cooling air to be supplied to oil cooler 28, which serves as a heat exchanger, thereby increasing the cooling efficiency of oil cooler 28 and further improving the cooling performance of oil cooler 28.

[0094] Furthermore, when the air volume adjustment units 50 and 51 have air volume restriction bodies 44 and 49 in which a plurality of openings, that is, holes 44a1 and 49a1, are formed, the amount of outside air taken in from the intermediate air inlet 30e can be adjusted simply by changing the shape, size, number, position, etc. of the holes 44a1 and 49a1 formed in the air volume restriction bodies 44 and 49. This allows the air volume adjustment units 50 and 51 to be formed with a simple configuration, which reduces the cost and number of parts and enables a reduction in manufacturing costs.

[0095] As shown in FIGS. 6, 7, and 9, a flow straightening plate 48 is provided extending from the vicinity of the front side surface 28d of the oil cooler 28 toward the lower wall 30b of the cooling air duct 10.

[0096] The straightening plate 48 has a triangular shape when viewed from the front, and its bottom is bent forward to form a fixing stay 48a, which is fastened and fixed onto the lower wall 30b of the cooling air duct 10.

[0097] Furthermore, by extending the straightening plate 48 parallel to the duct axis 31, it acts almost as little resistance to the cooling air flowing through the air passage 32 from the end inlet 10a1 to the radiator 11.

[0098] As a result, a separation rectifier 52 that divides the air passage 32 into a first air passage 32a that connects from the end suction port 10a1 to the oil cooler 28, which is the heat exchanger, and a second air passage that connects from the end suction port 10a1 directly to the radiator 11, is formed by such a plate-shaped rectifier plate 48.

[0099] Furthermore, a gap 56 is provided on the end inlet 10a1 side of the straightening plate 48, and through this gap 56, first air passage 32a and second air passage 32b are partially in communication with each other.

[0100] This allows the first cooling air 53 that flows through the first air passage 32a and collides with the heat exchange section 28a of the oil cooler 28 to easily merge with the second cooling air 54 flowing through the second air passage 32b through the gap 56 on the end intake port 10a1 side of the straightening plate 48.

[0101] In other words, when a separating and rectifying device 52 is provided that separates air passage 32 from end suction port 10a1 to radiator 11 near engine 6 into first air passage 32a that connects end suction port 10a1 to heat exchanger 28a, and second air passage 32b that connects end suction port 10a1 directly to radiator 11, the cooling air from end suction port 10a1 is separated into first cooling air 53 that passes through first air passage 32a and is supplied to heat exchangers such as oil cooler 28 and condenser, and second cooling air 54 that passes through second air passage 32b and is supplied directly to radiator 11 near engine 6, and therefore the first cooling air 53 and second cooling air 54 do not interfere with each other and the wind direction and air volume are kept constant.

[0102] As a result, the oil cooler 28 located midway through the air path 32 acts as a resistor to the cooling air flowing within the single air path 32, causing the entire cooling air to become turbulent and resulting in large fluctuations in air direction and volume, whereas the first cooling air 53 and the second cooling air 54 are both in a laminar flow state, resulting in more stable air direction and volume, thereby increasing the cooling efficiency of heat exchangers such as the oil cooler 28 and radiator 11 and further improving the cooling performance of the heat exchangers.

[0103] Furthermore, the separating and rectifying unit 52 has a rectifying plate 48 that extends parallel to the duct axis 31 from near the front side surface 28d, which is the side surface of the heat exchange section 28a, toward the lower wall 30b, which is the side wall of the cooling air duct 10, and when a gap 56 that partially connects the first air passage 32a and the second air passage 32b is provided on the side of the end inlet 10a1 of this rectifying plate 48, the rectifying plate 48 is parallel to the duct axis 31 and acts as almost no resistance to the cooling air flowing within the air passage 32, so that cooling air can be supplied to both the first air passage 32a and the second air passage 32b in a stable direction and at a stable volume without becoming turbulent.

[0104] In this way, the first air passage 32a is provided on one side of the rectifying plate 48 and the second air passage 32b is provided on the other side, so that the separation rectifying plate 52 can be formed with a simple configuration, and the cost and number of parts can be reduced, thereby reducing manufacturing costs.

[0105] In addition, the first cooling air 53 that flows through the first air passage 32a and collides with the oil cooler 28, which is the heat exchanger, can pass through the gap 56 on the side of the end inlet 10a1 of the straightening plate 48 and easily merge with the second cooling air 54 flowing through the second air passage 32b.This allows the first cooling air 53 to be quickly discharged without stagnating near the oil cooler 28, allowing cooling air to be continuously supplied to the oil cooler 28, increasing the cooling efficiency of the oil cooler 28 and further improving the cooling performance of the oil cooler 28.

[0106] Next, a maintenance structure for inspecting, cleaning, washing, etc., the heat exchangers such as the radiator 11 and oil cooler 28 and the surrounding areas will be described with reference to FIGS.

[0107] As mentioned above, an intermediate intake port 30e having a rectangular shape in a plan view is opened in the middle of the lower wall 30b of the cooling air duct 10, and a dust removal screen 43 is removably fastened to the underside of the edge of this intermediate intake port 30e.

[0108] An air flow restrictor 44 is detachably attached to the frame 43a of the dustproof screen 43 from above.

[0109] Furthermore, the oil cooler 28 is set in an inclined position diagonally outward and upward by a rotating portion 39 provided on the upper wall 30a of the cooling air duct 10 for rotating the oil cooler 28 around the outer portion 28b, and a lower engaging portion 40 provided on the lower wall 30b of the cooling air duct 10 for engaging the inner portion 28c of the oil cooler 28.

[0110] In addition to this configuration, an upper locking portion 58 is formed above the lower locking portion 40. In this upper locking portion 58, a U-shaped winding grip 57 that opens downward when viewed from the right side is fixed to the underside of the upper wall 30a of the cooling air duct 10 by a fixing device 61, and two winding portions 57a that can easily be plastically deformed extend from this winding grip 57.

[0111] The maintenance structure 60 is made up of the above-described intermediate suction port 30e, the detachable dust screen 43, the rotating part 39 for changing the position of the oil cooler 28, the lower retaining part 40, the upper retaining part 58, etc.

[0112] When performing maintenance work using this maintenance structure 60, first loosen the aforementioned bolts 46, remove the dust removal screen 43 with the air flow restrictor 44 of the air flow adjustment unit 50 still attached to its upper surface from the intermediate suction port 30e, and open the intermediate suction port 30e.

[0113] In this case, air volume adjustment unit 50 is detachably attached to midway suction port 30e via dust removal screen 43 using a simple attachment / detachment structure such as bolts 46 and 47, and air volume adjustment unit 50 can be attached to and detached from midway suction port 30e in a short time and without much effort.

[0114] When maintenance work is to be performed separately on the dust screen 43 and the air flow restrictor 44 , the bolts 47 are loosened and the air flow restrictor 44 is removed from the top surface of the dust screen 43 .

[0115] Next, the bolt 41 is loosened, and the inner portion 28c located near the midway suction port 30e is removed from the fixed stay 37.

[0116] Then, by pushing up the inner portion 28c through the intermediate suction port 30e, the inner portion 28c is rotated and raised in the clockwise direction 59 in rear view around the outer portion 28b, which is farther from the intermediate suction port 30e than the inner portion 28c, and the oil cooler 28 is placed in an approximately horizontal position.

[0117] This opens the intermediate suction port 30e, allowing easy access to the inside of the cooling air duct 10, particularly to the oil cooler 28 located close to the intermediate suction port 30e. At the same time, the inner portion 28c rises to the vicinity of the upper locking portion 58, and the fuel supply hose 33 extending from the front side surface 28d of the oil cooler 28 also rises to the vicinity of the winding grip 57 of the upper locking portion 58.

[0118] Therefore, with the oil cooler 28 maintained in an approximately horizontal position, the winding portion 57a ​​of the winding grip 57 is wound around the fuel supply hose 33 to prevent the inner portion 28c from descending, and the oil cooler 28 can be maintained in an approximately horizontal position.

[0119] In this approximately horizontal position, the lower half of the radiator 11 is completely exposed to the cooling air duct 10, so that visual inspection of the radiator 11, cleaning of the filter with a vacuum cleaner, and cleaning with a high-pressure cleaning water spray can be effectively performed through the intermediate intake port 30e.

[0120] In other words, when a maintenance structure 60 is provided that allows access to the cooling air duct 10 through the intermediate intake port 30e, this maintenance structure 60 makes it easy to perform maintenance through the intermediate intake port 30e that is close to the oil cooler 28, which is a heat exchanger, and improves the workability of maintenance work such as inspecting, cleaning, and washing the air volume adjustment unit 50 and heat exchangers such as the radiator 11 and oil cooler 28.

[0121] Furthermore, when the maintenance structure 60 has a detachable structure that detachably covers the air volume adjustment units 50 and 51 at the mid-way air intake port 30e, the detachable structure consisting of fasteners such as bolts 46 and 47 allows the air volume adjustment unit 50 to be detached quickly and easily at the start and end of maintenance work, further improving the workability of maintenance work such as inspecting, cleaning, and washing the air volume adjustment unit 50 and heat exchangers such as the radiator 11 and oil cooler 28.

[0122] In addition, when the maintenance structure 60 has a rotating part 39 that rotates the inner part 28c, which is one side part of the oil cooler 28, which is a heat exchanger, located near the intermediate suction port 30e, around the outer part 28b, which is the other side part that is farther from the intermediate suction port 30e than the inner part 28c, thereby moving the inner part 28c away from the intermediate suction port 30e and opening the intermediate suction port 30e, and an upper locking part 58 that is a locking part that locks the inner part 28c to maintain the open state, the inner part 28c of the oil cooler 28 can be rotated and locked around the outer part 28b, opening the intermediate suction port 30e, and the maintenance structure 60 can be formed with a simple configuration, and the cost and number of parts can be reduced, thereby reducing manufacturing costs.

[0123] As described above, the work vehicle according to the present invention is equipped with a heat exchanger cooling structure that can efficiently cool heat exchangers such as oil coolers and condensers without requiring the addition of a new structure or reducing design freedom, thereby improving the cooling performance of the heat exchanger.

[0124] Although the present invention has been described through the above-mentioned embodiments, the present invention is not limited to these. Furthermore, the above-mentioned effects are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the present embodiments.

[0125] For example, the present invention can take the following forms. (1) A work vehicle is provided with a body on which a work implement is mounted, the body being provided with a prime mover and a cooling air duct that guides outside air as cooling air toward the prime mover, A heat exchanger having a heat exchange section inclined with respect to the duct axis of the cooling air duct is disposed in the cooling air duct, and an end suction port having an opening surface substantially perpendicular to the duct axis is provided at the end of the cooling air duct outside the aircraft. A work vehicle characterized by: (2) An inlet port facing the heat exchanger is provided in the middle of the side wall of the cooling air duct. The work vehicle according to (1) above. (3) At least one of the end suction port and the intermediate suction port is provided with an air volume adjustment unit that adjusts the amount of outside air taken in. The work vehicle according to (2) above. (4) The airflow adjusting unit has an airflow restricting body in which a plurality of openings are formed. The work vehicle according to (3) above. (5) A separating and rectifying device is provided that divides the air passage from the end suction port to the motor into a first air passage that communicates from the end suction port to the heat exchanger and a second air passage that communicates directly from the end suction port to the motor. The work vehicle according to any one of (2) to (4) above, (6) The separating and rectifying unit has a rectifying plate extending parallel to the duct axis from the vicinity of the side surface of the heat exchange unit toward the side wall of the cooling air duct, and a gap is provided on the end inlet side of the rectifying plate to partially communicate between the first air passage and the second air passage. The work vehicle according to (5) above. (7) A maintenance structure is provided that allows access to the inside of the cooling air duct through the intermediate intake port. The work vehicle according to any one of (2) to (6) above, (8) The maintenance structure has a detachable structure that detachably covers the air volume adjusting unit at the midway air inlet. The work vehicle according to (7) above. (9) The maintenance structure has a rotating part that rotates one side part of the heat exchanger located near the mid-way suction port around another side part that is farther from the mid-way suction port than the one side part, and separates the one side part from the mid-way suction port to open the mid-way suction port, and a locking part that locks the one side part to maintain the open state. The work vehicle according to (7) or (8) above. [Explanation of symbols]

[0126] 1 Work vehicle 1a aircraft 2 Work equipment 4 Crawler-type running device (running device) 6 Engine (prime mover) 10 Cooling air duct 10a Outboard end 10a1 End suction port 10a2 opening surface 11 Radiator 28 Oil cooler (heat exchanger) 28a Heat exchange section 28b Outer part (other side) 28c Inner part (one side) 28d Front side (side of heat exchanger) 30b Lower wall (side wall of cooling air duct) 30e Mid-way suction port 31 Duct axis 32 Wind path 32a 1st wind path 32b 2nd wind path 39 Rotating part 44·49 Air flow restrictor 44a1・49a1 hole (opening) 48 Rectifier plate 50·51 Air volume adjustment part 52 Separation rectifier 52 56 Gap 58 Upper locking part (locking part) 60 Maintenance Structure

Claims

1. A work vehicle is provided with a vehicle body to which a work implement is attached, the vehicle body being provided with a prime mover and a cooling air duct that guides outside air as cooling air toward the prime mover, A heat exchanger having a heat exchange section inclined with respect to the duct axis of the cooling air duct is disposed in the cooling air duct, and an end suction port having an opening surface substantially perpendicular to the duct axis is provided at the end of the cooling air duct outside the aircraft. A work vehicle characterized by:

2. An inlet port facing the heat exchanger is provided in the middle of the side wall of the cooling air duct.

2. The work vehicle according to claim 1.

3. At least one of the end suction port and the intermediate suction port is provided with an air volume adjustment unit that adjusts the amount of outside air taken in.

3. The work vehicle according to claim 2.

4. The airflow adjusting unit has an airflow restricting body in which a plurality of openings are formed.

4. The work vehicle according to claim 3.

5. A separating and rectifying device is provided that divides the air passage from the end suction port to the motor into a first air passage that communicates from the end suction port to the heat exchanger and a second air passage that communicates directly from the end suction port to the motor.

5. The work vehicle according to claim 2, wherein the work vehicle is a vehicle having a plurality of shafts.

6. The separating and rectifying unit has a rectifying plate extending parallel to the duct axis from the vicinity of the side surface of the heat exchange unit toward the side wall of the cooling air duct, and a gap is provided on the end inlet side of the rectifying plate to partially communicate between the first air passage and the second air passage.

6. A work vehicle according to claim 5.

7. A maintenance structure is provided that allows access to the inside of the cooling air duct through the intermediate intake port.

5. The work vehicle according to claim 2, wherein the work vehicle is a vehicle having a plurality of shafts.

8. The maintenance structure has a detachable structure for detachably covering the air volume adjusting unit at the midpoint of the air intake port.

8. A work vehicle according to claim 7.

9. The maintenance structure has a rotating part that rotates one side part of the heat exchanger located near the mid-way suction port around another side part that is farther from the mid-way suction port than the one side part, and separates the one side part from the mid-way suction port to open the mid-way suction port, and a locking part that locks the one side part to maintain the open state.

8. A work vehicle according to claim 7.

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