Support structure for work vehicle and work vehicle

A support structure includes a shroud having a substantially circular shape from a proximal end covering an outer periphery of a first surface of a heat exchanger to a distal end. A support frame supports the heat exchanger and the shroud to expose the distal end and a second surface of the heat exchanger. The vehicle body frame has an opening. A cooling fan includes a fan rotating shaft and blades to generate cooling air. When the heat exchanger is positioned at the first position facing the cooling fan, the distal end of the shroud covers a circumference of the cooling fan in a radial direction so that cooling air passes through the first and second surfaces. When the support frame is located at a second position where the heat exchanger exposes the opening to an outside of the vehicle frame, the fan rotating shaft and the blades are uncovered.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U. S. C. § 119 to Japanese Patent Application No. 2021-213865, filed Dec. 28, 2021. The contents of this application are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a support structure for a work vehicle and to a work vehicle.

Discussion of the Background

Japanese Patent No. 6767270 discloses a work vehicle including a radiator fan provided in an engine compartment and a radiator provided on a member capable of being opened and closed with respect to the engine compartment.

SUMMARY OF THE INVENTION

According to one aspect of the present disclosure, a support structure for a work vehicle includes a heat exchanger, a shroud, a support frame, and a cooling fan. The heat exchanger has a first surface and a second surface opposite to the first surface in an air-flow direction in which cooling air is configured to pass through the heat exchanger. The shroud includes has a tubular shape extending from a proximal end to a distal end opposite to the proximal end in the air-flow direction. The proximal end covers an outer periphery of the first surface of the heat exchanger. The distal end has a substantially circular shape as viewed in the air-flow direction. The support frame is configured to support the heat exchanger and the shroud to expose the distal end of the shroud and the second surface of the heat exchanger. A vehicle body frame includes a support wall, and has an opening, a part of an outer periphery of the opening being defined by the support wall. The hinge is connected to the support wall and the support frame, and has a hinge rotation axis substantially parallel to a wall surface of the support wall to swing the support frame around the hinge rotation axis. A cooling fan includes a fan rotating shaft having a fan rotation axis around which the fan rotating shaft is configured to rotate, the fan rotating shaft being provided such that the fan rotating shaft passes through the opening and blades provided around the fan rotating shaft in the radial direction with respect to the fan rotation axis and configured to rotate around the fan rotation axis to generate cooling air. When the support frame is positioned at a first position where the heat exchanger faces the cooling fan, the distal end of the shroud is configured to cover a circumference of the cooling fan in the radial direction so that the cooling air passes through the first surface and the second surface of the heat exchanger. When the support frame is located at a second position where the heat exchanger exposes the opening to an outside of the vehicle body frame, the fan rotating shaft and the blades being configured to be uncovered. The hinge rotation axis and fan rotation axis are skew lines. The hinge rotation axis is arranged such that, when the support frame is located at the second position, the hinge rotation axis is arranged so that the hinge rotation axis does not overlap the support wall as viewed from the width direction perpendicular to the hinge rotation axis and the fan rotation axis. A work vehicle according to a second aspect of the present disclosure includes the support structure according to the first aspect.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention will be described below with reference to the accompanying drawings. Similar reference numerals indicate corresponding or identical components in the drawings.

First Embodiment

Referring toFIG.1, a work vehicle1, for example, a small-sized truck loader, includes a support structure100of a heat exchanger7according to a first embodiment of the present invention. A work vehicle1includes a main frame2, a traveling device3, a working device4, and a cabin5. The main frame2supports the traveling device3, the working device4, and the cabin5. In the illustrated embodiment, the traveling device3is a crawler traveling device3. However, the traveling device3is not limited to the crawler traveling device3. The traveling device3may be, for example, a front wheel/rear wheel traveling device, or a traveling device3having a front wheel and a rear crawler. The working device4is provided with an implement (bucket)41at the distal end12of the working device4. A proximal end of the working device4is attached to a rear portion of the main frame2. A working device4includes a pair of arms42for rotatably supporting the implement (bucket)41via a bucket rotational shaft43. Each of the pair of arms42includes a lift link44and a boom45. The lift link44is rotatable about the first pivot pin46with respect to the main frame2. The boom45is rotatable about the second pivot pin47with respect to the lift link44. The working device4further includes a boom cylinder48and at least one implements cylinder49. Each boom cylinder48is rotatably connected to the main frame2and the boom45, and operates the lift link44and the boom45to raise and lower the implement (bucket)41. At least one implements cylinder49is configured to incline the implement (bucket)41. The cabin5is attached to a front portion of the main frame2. The work vehicle1includes a front door51provided at a front portion of the cabin5, a driver's seat52provided inside the cabin5, and an operating device (not illustrated).

In the illustrated embodiment, one of the pair of arms42is provided on the left side of the cabin5. The other of the pair of arms42is provided on the right side of the cabin5. Specifically, one of the boom cylinder48and the boom45is provided on the left side of the cabin5. The other boom cylinder48and the other boom45are provided on the right side of the cabin5.FIG.1shows the left side of the work vehicle1. However, the left and right sides of the work vehicle1are substantially symmetrical.

The work vehicle1further includes an engine6, a heat exchanger7, a shroud10, and a cooling fan20provided at the rear portion of the main frame2. The engine6is configured to provide driving force to the traveling device3and the working device4. The heat exchanger7includes a radiator for cooling the cooling water of the engine6. Preferably, the heat exchanger7includes an oil cooler for cooling a hydraulic fluid used in a hydraulic system (e.g., a boom cylinder and at least one implements cylinder49) of the work vehicle1. The cooling fan20is configured to generate cooling air for cooling the heat exchanger7. The shroud10is configured to cover the outer circumference of the cooling fan20to efficiently send cooling air to the heat exchanger7. The engine6, the heat exchanger7, the shroud10and the cooling fan20are provided between a pair of arms42in the left-right direction of the work vehicle1. The engine6, the heat exchanger7, the shroud10and the cooling fan20are provided between the boom cylinders48in the lateral direction of the work vehicle1.

The work vehicle1further includes a vehicle body frame8and bonnet cover9. The vehicle body frame8includes a room cover that covers the front and peripheral portions of the engine6and the cooling fan20. The bonnet cover9is provided at the rear end of the main frame2and covers an opening82.FIG.2is a partial rear view of the periphery of the bonnet cover9of the work vehicle1. Referring toFIG.2, the bonnet cover9is swingable about a cover rotation axis Axc. InFIG.2, since the hinge91for rotating the bonnet cover9exists on the back side of the bonnet cover9, the hinge91is shown by a dotted line. The vehicle body frame8includes an upper cover89positioned above and forward of the bonnet cover. The upper cover89is openable and closable.

FIG.3is a partial rear view of the work vehicle1when the bonnet cover9is removed. Referring toFIGS.1and3, the vehicle body frame8includes a support wall81and has the opening82having the support wall81as a part of its outer periphery.FIG.4shows the cooling fan20, the shroud10, and the heat exchanger7as viewed from the engine6.FIG.5is a perspective view showing a support structure100of the heat exchanger7according to the first embodiment. InFIGS.3and4, the pair of arms42is not illustrated. Referring toFIGS.3-5, the heat exchanger7includes a first surface71and a second surface72opposite to the first surface71in the thickness direction (air-flow direction) Dt. The cooling air is configured to flow through the heat exchanger7in the air-flow direction Dt. Referring toFIGS.4and5, the shroud10includes a proximal end11covering the outer periphery of the first surface71of the heat exchanger7and a distal end12having a substantially circular shape as viewed in the thickness direction Dt. The shroud10includes a tubular shape extending in the thickness direction Dt from the proximal end11to the distal end12.

The work vehicle1is further provided with a support frame30and a hinge93. The support frame30supports the heat exchanger7and the shroud10to expose the distal end12of the shroud10and the second surface72of the heat exchanger7. As shown inFIGS.3and5, the support frame30is a frame-shaped member that surrounds an outer peripheral surface connecting the first surface71and the second surface72of the heat exchanger7. Referring toFIG.3, the hinge93is connected to the support wall81and the support frame30. The hinge93is configured to swing the support frame30around a hinge rotation axis Axh substantially parallel to the wall surface of the support wall81. More specifically, the hinge93has a hinge rotation axis Axh, extends along the hinge rotation axis Axh, and is attached to the hinge rotation shaft94and the support wall81that can swing together with the support frame30, and includes a shaft support plate95having a through hole through which the hinge rotation shaft94passes. As a result, the support frame30can be opened and closed so that the heat exchanger7can be rotated rearward, and a maintenance operator can perform maintenance work on the heat exchanger7and the engine6.

FIG.6is a top view of the rear portion of the work vehicle1when the upper cover89is removed. InFIG.6, the engine6is not illustrated. As shown inFIG.6, the hinge rotation axis Axh is provided on the opposite side of the cover rotation axis Axe with respect to the opening82. That is, the bonnet cover9and the support frame30are configured to open on opposite sides, respectively. Therefore, the bonnet cover9and the support frame30form double doors opening from the center, and the second surface72can be covered by the bonnet cover9. Referring toFIGS.2and3, the bonnet cover9has a plurality of air holes92in a portion opposed to the second surface72when rotated to a position at which the bonnet cover9covers the second surface72. After cooling the heat exchanger7and the engine6, the outside air sucked in through an air hole92(not illustrated) of the upper cover89is discharged through the air hole92of the upper cover89.

Further, as shown inFIGS.5and6, the support frame30has a roller32at its lower end, and the roller32rolls on the bottom wall83of the vehicle body frame8when the maintenance worker moves the support frame30, so that the maintenance worker can easily move the support frame30. Further, since the support frame30is supported by the bottom wall83through the rollers32during operation of the work vehicle1, it is suppressed that a large load is applied to the hinge93for a long time.

Referring toFIGS.3to5, the cooling fan20includes a fan rotating shaft21and a plurality of blades22. The fan rotating shaft21has and extends along a fan rotation axis Axf around which the fan rotating shaft21is configured to rotate, the fan rotating shaft21being provided such that the fan rotating shaft21passes through the opening82. As shown inFIG.3and the like, fan rotation axis Axf and hinge rotation axis Axh are skew lines. Preferably, when the fan rotation axis Axf is projected onto the surface including the rotation axis Axh, the projected line is orthogonal to the hinge rotation axis Axh. However, when the fan rotation axis Axf is projected onto the surface including the hinge rotation axis Axh, the projected line is orthogonal to the hinge rotation axis Axh. The plurality of blades22are provided around the fan rotating shaft21in the radial direction with respect to the fan rotation axis Axf. The cooling fan20is configured to rotate the plurality of blades22around the fan rotation axis Axf to generate cooling air.

Further, referring toFIG.6, when the support frame30is positioned on the first position P1at which the heat exchanger7faces the cooling fan20, the distal end12of the shroud10is configured to cover a circumference of the cooling fan20in the radial direction so that the cooling air passes through the first surface71and the second surface72. As shown inFIG.6andFIG.7to be described later, when the support frame30is positioned at a second position P2where the heat exchanger7exposes the opening82to an outside of the vehicle body frame8, the fan rotating shaft21and the plurality of blades22are configured to be uncovered. As shown in the enlarged view of area A inFIG.6, the support frame30includes a connecting member31connected to the hinge rotation shaft94. This connecting member31includes a notch31C for preventing contact with the hinge93and the support wall81during rotation. Further, the hinge93is configured such that a hinge rotation axis Axh is arranged so that the hinge rotation axis Axh does not overlap with the support wall81as viewed from the width direction Dw perpendicular to the fan rotation axis Axf. Specifically, as shown in the enlarged view of region A inFIG.6, the hinge rotation axis Axh is located behind the rear end81RE of the support wall81. In the present embodiment, the hinge rotation axis Axh, the fan rotation axis Axf, and the width direction Dw are substantially perpendicular to each other.

As a result, the heat exchanger7, the support frame30, and the shroud10can be rotated 90 degrees or more around the hinge rotation axis Axh. That is, the orientation of the support frame30at the second position P2is obtained by rotating 90 degrees or more about the hinge rotation axis Axh from the orientation of the support frame30at the first position P1. InFIG.6, the heat exchanger7, the support frame30and the shroud10at the first position P1are shown by a solid line, and the support frame30and the shroud10at the second position P2are shown by two-dot chain lines. the support frame30at the second position P2is shown by a one dot chain line. The second position as illustrated indicates a position obtained by rotating 90 degrees from the first position P1. Therefore, the heat exchanger7, the support frame30, and the shroud10can be further rotated about the hinge rotation axis Axh than the illustrated second position P2.

FIG.7is a perspective view as seen from the rear when the heat exchanger7, the support frame30, and the shroud10are arranged at the second position P2. InFIG.7, the upper cover89is opened forwardly. As shown inFIG.7, when the support frame30is positioned at the second position P2, the fan rotating shaft21and the plurality of blades22are exposed. Therefore an internal space opposite to the opening82with respect to the cooling fan20is accessible through a gap between the opening82and the plurality of blades22.

Referring toFIGS.6and7, a part (proximal end11) of the shroud10(proximal end11), which is closer to the support wall81than the fan rotating shaft21in the width direction Dw when the support frame is positioned at the first position P1, has a notch13recessed toward the first surface71.FIG.8is a cross-sectional view of the vicinity of the notch13by a plane parallel to the width direction Dw and passing through the fan rotation axis Axf. InFIG.8, a region22R schematically shows a region through which the plurality of blades22pass when they rotate. The shroud10includes an extended region14located on the opposite side of the notch13with respect to the fan rotation axis Axf, and covers the outside in the radial direction with respect to the fan rotation axis Axf of the cooling fan20. When the shroud10includes the extended region14, the tip of the shroud10passes through the path R0shown in the figure and comes into contact with the plurality of blades22. In the present embodiment, the shroud10is configured to do not contact the plurality of blades22by the notch13having a configuration in which the extended region14is removed, so that the tip of the notch13passes through the path R1when the support frame30is rotated.

FIG.9is an enlarged perspective view of the vicinity of the shroud10when the support frame30is located at the second position P2. Referring toFIGS.5and9, the heat exchanger7further includes a first connection port PT1for connecting with a pipe TU1through which a liquid, which is a refrigerant or a working fluid, flows. The heat exchanger7further includes a second connection port PT2for connecting with a pipe TU2through which a liquid as a refrigerant or a working oil flows. The heat exchanger7includes a first swivel joint SJ1provided at a position closer to the hinge rotation axis Axh than a first connection port PT1and a second swivel joint SJ2provided at a position closer to the hinge rotation axis Axh than a second connection port PT2. A heat exchanger7includes a pipe TU1which connects a first connection port PT1and a first swivel joint SJ1and through which the liquid flows, a pipe TU2which connects a second connection port PT2and a second swivel joint SJ2and through which the liquid flows, a pipe TU3which connects the first swivel joint SJ1and a third connection port CT1which is a source or destination of the liquid, and a pipe TU4which connects the second swivel joint SJ2and a fourth connection port CT2which is a source or destination of the liquid. The third connection port CT1is, for example, a connection port of the hydraulic oil tank. The fourth connection port CT2is, for example, a connection port to the engine6configured to rotate the cooling fan20. The pipes TU1and TU2may be referred to as a first pipe. The pipes TU3and TU4may be referred to as second pipe.

FIG.5shows a support structure100of the heat exchanger7when the support frame30is located at the first position P1of the heat exchanger7. Referring toFIG.5, the distance DJ1between the first swivel joint SJ1and the hinge rotation axis Axh in an additional radial direction Dr with respect to the hinge rotation axis Axh (inFIG.5, the additional radial direction Dr is the same as the width direction Dw) is shorter than the distance DT1in the additional radial direction Dr between the first connection port PT1and the hinge rotation axis Axh. The additional radial direction Dr is perpendicular to the hinge rotation axis Axh. The distance DJ2in the additional radial direction Dr between the second swivel joint SJ2and the hinge rotation axis Axh is shorter than the distance DT2in the additional radial direction Dr between the second connection port PT2and the hinge rotation axis Axh. When the first connection port PT1and the third connection port CT1are connected to each other by one pipe without providing the first swivel joint SJ1, it is necessary to bend the pipe by about 90 degrees so that the pipe does not interfere with the cooling fan20. When the second connection port PT2and the fourth connection port CT2are connected by one pipe without providing the second swivel joint SJ2, it is necessary to bend the pipe by 90 degrees or more so that the pipe does not interfere with the cooling fan20. By utilizing the first swivel joint SJ1and the second swivel joint SJ2, it is possible to improve the flexibility of the pipe arrangement. In particular, large bending of the pipe for routing is inhibited.

Effect of First Embodiment

In the support structure100of the heat exchanger7according to the first embodiment, when the support frame30is located at a second position P2where the heat exchanger7exposes the opening82to the outside of the vehicle body frame8, the fan rotating shaft21and the plurality of blades22are exposed. Therefore, when the member provided with the heat exchanger7is opened, access to the engine compartment is facilitated by utilizing the gap between the opening82and the plurality of blades22. In addition, since the notch13is configured such that the extended region14is removed, the shroud10does not come into contact with the plurality of blades22when the support frame30rotates.

Second Embodiment

FIG.10shows a support structure110of a heat exchanger according to a second embodiment. InFIG.10, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the support structure110of the heat exchanger7according to the second embodiment, since the hinge rotation axis Axh defined by the hinge rotation shaft94can slide up to Axh_out shown inFIG.8, the tip of the notch13passes through the path R2when the support frame30rotates, even if the shroud10aaccording to the present embodiment includes the extended region14(even if there is no notch13), so that the shroud10adoes not come into contact with the plurality of blades22.

Thus, inFIG.10, the support structure110includes a hinge93awith a shaft support plate95ahaving a slot96through which the hinge rotation shaft94passes. The slot96extends in a guide direction Dg intersecting with the hinge rotation axis Axh. More specifically, the guide direction Dg is perpendicular to the hinge rotation axis Axh. The shaft support plate95ahas a support surface97extending in the guide direction Dg. The support frame30afurther includes a connecting member31aconnected to the hinge rotation shaft94. The connecting member31ahas a contact surface33slidably in contact with the support surface97.

As shown inFIG.8, when the hinge rotation shaft94is located at one end of the slot96(Axh inFIG.8), the support frame30ais configured to swing around the hinge rotation axis Axh to contact the plurality of blades22. When hinge rotation shaft94is located at the other end (Axh_out in the figure) that is opposite to one end of slot96, and the support frame30ais configured to swing around the hinge rotation axis Axh (Axh_out in the figure) without contacting the plurality of blades22. Therefore, when the support frame30ais moved to the second position P2, the hinge rotation axis Axh is located at the position Axh_out in the figure. Therefore, the hinge rotation axis (Axh_out in the figure) is arranged so that when the support frame30ais positioned at the second position P2, the hinge rotation axis (Axh_out in the figure) does not overlap with the support wall81as viewed from the width direction Dw. When the support frame30ais positioned at the first position P1, the hinge rotation shaft94is positioned such that the hinge rotation axis Axh corresponds to the hinge rotation axis Axh inFIG.8.

Effect of Second Embodiment

The support structure110of the heat exchanger according to the second embodiment has a hinge93aincluding a shaft support plate95ahaving a slot96through which the hinge rotation shaft94passes. The slot96extends in a guide direction Dg intersecting with the hinge rotation axis Axh. When the hinge rotation shaft94is located at one end (Axh in the figure) of the slot96, the support frame30acan be brought into contact with the plurality of blades22by swinging the support frame30aaround the hinge rotation axis Axh. When the hinge rotation shaft94is located at the other end (Axh_out in the figure) opposite to the one end of the slot96and the support frame30ais swung around the hinge rotation axis (Axh_out in the figure), the support frame30adoes not contact with the plurality of blades22. Therefore, it is not necessary for the shroud10ato provide the notch13. As a result, when the support frame30ais located at the first position P1, the shroud10acan completely cover the periphery of the plurality of blades22, so that the cooling efficiency of the heat exchanger7can be improved. Further, since the hinge rotation shaft94can be slid to the position of Axh_out and the support frame30acan be largely rotated, the engine compartment can be easily accessed through the gap between the opening82and the plurality of blades22.

As used herein, “comprising” and its derivatives are non-limiting terms that describe the presence of a component, and do not exclude the presence of other components not described. This also applies to “having”, “including” and their derivatives.

The terms “member,” “part,” “element,” “body,” and “structure” may have multiple meanings, such as a single part or multiple parts.

Ordinal numbers such as “first” and “second” are simply terms used to identify configurations and do not have other meanings (e.g., a particular order). For example, the presence of the “first element” does not imply the presence of the “second element”, and the presence of the “second element” does not imply the presence of the “first element”.

Terms such as “substantially”, “about”, and “approximately” indicating degrees can mean reasonable deviations such that the final result is not significantly altered, unless otherwise stated in the embodiments. All numerical values described herein may be interpreted to include words such as “substantially,” “about,” and “approximately.”

In the present application, the phrase “at least one of A and B” should be interpreted to include only A, only B, and both A and B.

In view of the above disclosure, it will be apparent that various changes and modifications of the present invention are possible. Therefore, the present invention may be carried out by a method different from the specific disclosure of the present application without departing from the spirit of the present invention.