1. A work vehicle having a vehicle body front part provided with an engine, an engine cooling radiator provided at a vehicle body front side of the engine, a rotary fan provided between the engine and the radiator and which sucks cooling air from a vehicle body front side with respect to the radiator to the radiator, an 10 engine air cleaner, and a prime mover provided at a vehicle body front side with respect to the radiator and including an intake opening which causes the air cleaner to suck engine combustion air, wherein the intake opening opens in a rearward and downward direction of the vehicle body, in a portion where the sucked cooling air by the rotary fan passes through at the vehicle body front side 15 of the radiator.

2. The work vehicle according to claim 1, wherein the intake opening is a rear upward inclined planar opening having an upper end side located toward rear of the vehicle body.

3. The work vehicle according to claim 1 or 2, wherein the air cleaner is provided 20 at a vehicle body front side with respect to the radiator, and a discharge port of the air cleaner is coupled to the engine via an air supply pipe.

TECHNICAL FIELD
The present invention relates to a work vehicle having a vehicle body front part
provided with an engine, an engine cooling radiator provided at a vehicle body
front side of the engine, a rotary fan provided between the engine and the radiator
and which sucks cooling air from a vehicle body front side with respect to the
10 radiator toward the radiator, and a prime mover including an engine air cleaner.
RELATED ART
In the above work vehicle, the intake opening through which the air cleaner sucks
the engine combustion air is provided in a portion where the sucked cooling air by
15 the rotary fan passes through at the vehicle body front side with respect to the
radiator, whereby engine combustion air can be taken from the cooling air sucked
by the rotary fan and before cooling the radiator.
An example of this type includes a tractor disclosed in JP 2012-201159 A. In the
20 tractor disclosed in JP 2012-201159 A, a radiator is disposed in front of an engine,
and a fan is provided behind the radiator. The fan is driven by the engine and
sucks the air outside an engine room to the inside and sends the sucked air from
the front of the radiator to the engine side. An air cleaner and an intake port of
the air cleaner are provided in front of the radiator.
25
SUMMARY
In the above work vehicle, the cooling air is sucked from the vehicle body front
side of the radiator, and the dust is mixed in the cooling air and easily flows near
the intake opening. As a result, in a case where the dust is easily sucked into the
30 air cleaner together with the engine combustion air, maintenance work such as
2
5 filter replacement of the air cleaner needs to be frequently performed.
The present invention provides a work vehicle in which dust is hardly sucked by
an air cleaner while sucking engine combustion air from cooling air before acting
on a radiator.
10
A work vehicle according to the present invention has a vehicle body front part
provided with an engine, an engine cooling radiator provided at a vehicle body
front side of the engine, a rotary fan provided between the engine and the radiator
and which sucks cooling air from a vehicle body front side with respect to the
15 radiator to the radiator, an engine air cleaner, and a prime mover provided at a
vehicle body front side with respect to the radiator and including an intake
opening which causes the air cleaner to suck engine combustion air, wherein the
intake opening opens in a rearward and downward direction of the vehicle body,
in a portion where the sucked cooling air by the rotary fan passes through at the
20 vehicle body front side of the radiator.
According to the present configuration, the intake opening opens in the portion
where the sucked cooling air by the rotary fan passes through at the vehicle body
front side of the radiator. Therefore, the engine combustion air is sucked from
25 the cooling air before acting on the radiator.
According to the present configuration, the intake opening opens in the rearward
and downward direction of the vehicle body. Therefore, even if the dust flows
downward from above, the dust hardly enters the intake opening.
The suction direction at the intake opening is opposite to the opening direction of
30 the intake opening. Meanwhile, the flowing dust mixed in the cooling air has
3
5 dust moving force in the rearward and downward direction of the vehicle body by
composition of moving force in a rear direction of the vehicle body imparted by
the cooling air and moving force in a downward direction of the vehicle body
imparted by gravity. Therefore, suction of the combustion air through the intake
opening is performed in an opposite or nearly opposite direction to the direction
10 of the dust moving force. That is, the dust moving force becomes resistance
against the dust suction through the intake opening, and the dust is hardly sucked
into the intake opening.
Therefore, the dust is hardly sucked by the air cleaner while the engine
15 combustion air can be sucked from the cooling air before acting on the radiator.
In the present invention, it is favorable that the intake opening is a rear upward
inclined planar opening having an upper end side located toward the rear of the
vehicle body.
20 According to the present configuration, the shape of the intake opening can be
made into a flat and simple shape, and the dust can be made hardly sucked at a
low cost.
In the present invention, it is favorable that the air cleaner is provided at a vehicle
25 body front side with respect to the radiator, and a discharge port of the air cleaner
is coupled to the engine via an air supply pipe.
According to the present configuration, temperature rise of the air cleaner due to
heat radiation of the engine can be easily suppressed as compared with the air
30 cleaner being located at vehicle body rear side with respect to the radiator.
4
5 BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a right side view illustrating the entire tractor;
FIG. 2 is a plan view illustrating the entire tractor;
FIG. 3 is a right side view illustrating a prime mover;
FIG. 4 is a plan view illustrating the prime mover;
10 FIG. 5 is a front view illustrating the prime mover; and
FIG. 6 is a longitudinal sectional side view illustrating an intake opening.
DETAILED DESCRIPTION
Hereinafter, a case in which an embodiment of the present invention is applied to
15 a tractor as an example of a work vehicle will be described with reference to the
drawings. FIG. 1 is a right side view illustrating the entire tractor. The
direction [F] illustrated in FIGS. 1 and 2 is defined as a front direction of a
traveling vehicle body 1 and the direction [B] in FIGS. 1 and 2 is defined as a rear
direction of the traveling vehicle body 1. The direction [L] in FIG. 2 is defined
20 as a left direction of the traveling vehicle body 1 and the direction [R] in FIG. 2 is
defined as a right direction of the traveling vehicle body 1.
As illustrated in FIGS. 1 and 2, the tractor includes the traveling vehicle body 1
equipped with a pair of right and left front wheels 2 in a steerable and drivable
manner and equipped with a pair of right and left rear wheels 3 in a drivable
25 manner. The prime mover 4 is provided in a front part of the traveling vehicle
body 1. The prime mover 4 is provided with an engine 5, an engine hood 6 that
covers the engine 5, and the like. A driving section 7 is provided in a rear part of
the traveling vehicle body 1. The driving section 7 is provided with a driver’s
seat 8 and a steering wheel 9 for steering the front wheels 2. A link mechanism
30 10 is provided at the rear part of the traveling vehicle body 1 in an up-down
5
5 operable manner.
The tractor constitutes, for example, a riding-type cultivator by coupling a rotary
cultivator (not illustrated) to the rear part of the traveling vehicle body 1 via the
link mechanism 10 in an up-down operable manner.
As illustrated in FIG. 1, a vehicle body frame 11 of the traveling vehicle body 1 is
10 constituted by a front transmission case 12 having a front part coupled with the
engine 5 and a rear part of a clutch housing 5a provided at the rear of the engine 5,
a rear transmission case 13 having a front part coupled with a rear part of the front
transmission case 12, and a front frame 14 having a rear part coupled with a lower
part of the engine 5 and the front part of the front transmission case 12. As
15 illustrated in FIGS. 3 and 6, the front frame 14 includes a pair of right and left
inner frame members 14a having rear parts coupled with lower parts at both
lateral sides of the engine 5, outer frame members 14b coupled with the front part
of the front transmission case 12 and front parts of the inner frame members 14a
at lateral outsides of the right and left inner frame members 14a, and a front frame
20 member 14c having a rear part coupled with the front parts of the right and left
inner frame members 14a. The rear wheels 3 are drivably supported on both
lateral side parts of the rear transmission case 13. Power from the engine 5 is
transmitted to the front wheels 2 and the rear wheels 3 via the front transmission
case 12 and the rear transmission case 13. The right and left front wheels 2 are
25 supported by the front frame 14 via a front wheel drive case 15. Front wheel
power output from the front transmission case 12 is transmitted to the right and
left front wheels 2 via the front wheel drive case 15.
As illustrated in FIGS. 3 and 4, the prime mover 4 is provided with an engine
cooling radiator 16, an engine air cleaner 17, and an engine exhaust muffler 18, in
30 addition to the engine 5 and the engine hood 6. An engine fuel tank 19 is
6
5 provided above the engine 5. The fuel tank 19 is covered by a heat shielding
member 20 from below, above, and lateral sides. Heat radiation of the engine
and the exhaust muffler to the fuel tank 19 is suppressed by the heat shielding
member 20.
The engine 5 is supported on the rear part of the front frame 14. The radiator 16
10 is provided at a vehicle body front side with respect to the engine 5 and is
supported by the front frame 14 and a pair of right and left post members 21.
That is, a lower part of the radiator 16 is supported by the front parts of the right
and left inner frame members 14a of the front frame 14. Support arms 21a
extends rearward from upper parts of the right and left post members 21. Upper
15 parts of the radiator 16 are supported by the right and left post members 21 via the
support arms 21a. The right and left post members 21 are supported by the front
frame member 14c via a support plate 22. The radiator 16 and the engine 5 are
coupled via an upper hose 16a and a lower hose (not illustrated). A dust filter 23
is provided at a front surface side of the radiator 16.
20 A rotary fan 24 is provided between the engine 5 and the radiator 16. A fan
shroud 25 that covers the rotary fan 24 from an outer peripheral side is supported
by the radiator 16. A rotation support shaft 24a of the rotary fan 24 is supported
by a rotation support part 5b of the engine 5 in a relatively non-rotatable manner.
The rotation support part 5b is interlockingly coupled to an output shaft (not
25 illustrated) of the engine 5 via an endless belt 26.
The rotary fan 24 is rotationally driven by the engine 5 to send air rearward. Air
outside the engine hood 6 is sucked through an intake part 6a (see FIG. 3) of the
engine hood 6 to a vehicle body front-side place of the radiator 16 in the engine
hood due to suction force generated by the blowing of the rotary fan 24, whereby
30 cooling air generated by the suction of the air is sucked into the radiator 16
7
5 through the dust filter 23. Engine cooling water in the radiator is cooled by heat
exchange with the cooling air, and the engine 5 is cooled by the cooled cooling
water.
As illustrated in FIGS. 3, 4, and 5, the air cleaner 17 is provided at a vehicle body
10 front side with respect to the radiator 16 and is supported by a support member 27.
An attachment part 27a of the support member 27 is coupled to the right and left
post members 21. The air cleaner 17 is supported by the right and left post
members 21 via the support member 27. A discharge tube part 17a is installed in
a protruding manner in a lateral side part of the air cleaner 17, and an opening of
15 the discharge tube part 17a constitutes a discharge port 17b of the air cleaner 17.
The discharge port 17b is coupled to an intake part 5c of the engine 5 via an air
supply pipe 28. The air supply pipe 28 is arranged to pass in a front-rear
direction above a lateral one end part of the radiator 16.
20 As illustrated in FIGS. 3 and 5, an intake duct 29 extends from an intake tube part
17c installed in a protruding manner in the air cleaner 17 to the vicinity of the
front surface of the radiator 16, and an extended end opening of the intake duct 29
constitutes the intake opening 30. As illustrated in FIGS. 3, 5, and 6, the intake
opening 30 opens in a rearward and downward direction of the vehicle body in a
25 portion where the sucked cooling air by the rotary fan 24 passes through at the
vehicle body front side of the radiator 16. The intake opening 30 is formed into
a rear upward inclined planar opening having an upper end side located toward the
rear of the vehicle body.
As intake force of the engine 5 acts on the air cleaner 17 via the air supply pipe 28,
30 suction force F is generated in the intake opening 30 as illustrated in FIG. 6. As
8
5 a result, engine combustion air is sucked from the cooling air at the vehicle body
front side of the radiator 16 into the air cleaner 17 through the intake opening 30.
As illustrated in FIG. 6, moving force f1 in a rear direction of the vehicle body is
imparted by the cooling air and moving force f2 in a downward direction of the
10 vehicle body is imparted by gravity to flowing dust a mixed with the cooling air,
so that the dust a has dust moving force r in a rearward and downward direction of
the vehicle body by composition of the moving force f1 and the moving force f2.
Since the intake opening 30 opens in the rearward and downward direction of the
vehicle body, the direction of action of the suction force F of the intake opening
15 30 becomes opposite or nearly opposite to the direction of the dust moving force r,
and the dust moving force r becomes resistance against dust suction through the
intake opening 30. As a result, suction of the engine combustion air through the
intake opening 30 is performed in a state where the dust is hardly sucked. The
engine combustion air sucked by the air cleaner 17 undergoes dust removal
20 treatment by a dust filter (not illustrated) provided in the air cleaner 17, and the
dust-removed engine combustion air is sucked into the engine 5 via the air supply
pipe 28.
The exhaust muffler 18 is provided in a lateral side place of the fuel tank 19 above
25 the engine 5. As illustrated in FIG. 4, an exhaust pipe 31 extends from a front part
of the exhaust muffler 18 toward a lateral outside of the engine hood 6. As
illustrated in FIG. 1, the exhaust pipe 31 is arranged to be vertically oriented along
an up-down direction of the vehicle body on the lateral outside of the engine hood
6.
30 [Another Embodiment]
9
5 (1) In the above embodiment, the example in which the air cleaner 17 is provided
at the vehicle body front side with respect to the radiator 16 has been described.
However, the air cleaner 17 may be provided at a vehicle body rear side with
respect to the radiator 16.
(2) In the above embodiment, the example in which the intake opening 30 is
10 formed into the planar opening has been described. However, an intake opening
having a stepped shape in which a step is formed between an upper end side part
and a lower end side part may be adopted.
The present invention can be applied to various types of work vehicles such as
mowers and rice transplanters besides tractors.

WE CLAIM:-
1. A work vehicle having a vehicle body front part provided with an engine, an
engine cooling radiator provided at a vehicle body front side of the engine, a
rotary fan provided between the engine and the radiator and which sucks cooling
air from a vehicle body front side with respect to the radiator to the radiator, an
10 engine air cleaner, and a prime mover provided at a vehicle body front side with
respect to the radiator and including an intake opening which causes the air
cleaner to suck engine combustion air, wherein the intake opening opens in a
rearward and downward direction of the vehicle body, in a portion where the
sucked cooling air by the rotary fan passes through at the vehicle body front side
15 of the radiator.
2. The work vehicle according to claim 1, wherein the intake opening is a rear
upward inclined planar opening having an upper end side located toward rear of
the vehicle body.
3. The work vehicle according to claim 1 or 2, wherein the air cleaner is provided
20 at a vehicle body front side with respect to the radiator, and a discharge port of the
air cleaner is coupled to the engine via an air supply pipe.