JP2018204498A - Working vehicle - Google Patents

Abstract

To satisfy a requirement that a disadvantage such as a freeze of a water component caused by the adhesion of the water component to a throttle valve should be avoided without causing a cost increase by the complication of a constitution.SOLUTION: A blowby gas reduction passage 32 for reducing a blowby gas discharged from an engine to a middle part of an intake path 26 is connected to a down-stage side of a circulation direction rather than an air cleaner 28 of the intake path 26, an inclined passage part 36 taking a downward inclined posture so as to be positioned in a lower position as progressing toward the down-stage side of the circulation direction, and having a drain part 37 at the lowest end part is arranged at a point at the down-stage side of the circulation direction of a reduction passage connecting point Q to which the blowby gas reduction passage 32 of the intake path 26 is connected, and a throttle valve 30 is arranged in a position which is substantially the same in a height with the reduction passage connecting point Q, or in a position higher than that position, and at the down-stage side of the circulation direction of the inclined passage part 36.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a work vehicle equipped with an engine.

  In a conventional work vehicle, an intake passage for taking in combustion air of the engine extends from the front of the vehicle body to the rear of the vehicle body, and an air cleaner is provided at a position near the rear side of the engine in the middle of the intake passage. A substantially horizontal intake passage is provided between the air cleaner and the intake intake port of the engine, and a throttle valve is provided in the middle (see, for example, Patent Document 1).

  Although not described in Patent Document 1, the blow-by gas reduction passage for reducing the blow-by gas discharged from the engine to the intake passage is connected to a position near the throttle valve in the middle of the route from the air cleaner to the engine. (For example, refer to Patent Document 2).

JP 2017-13690 A JP 2011-185181 A

  In the above-described conventional configuration, the blow-by gas discharged from the engine is reduced to a position close to the throttle valve, so that moisture contained in the blow-by gas may adhere to the throttle valve. In a cold region, the water adhering to the throttle valve may freeze in this way, and the throttle valve may not be operated satisfactorily.

  By the way, as a configuration for preventing icing as described above, a configuration in which the engine cooling water is circulated and supplied to the throttle valve to raise the temperature is conceivable. Therefore, there is a disadvantage that the structure is complicated and the cost is increased.

  Therefore, it has been desired to avoid disadvantages such as water adhering to the throttle valve and freezing without causing an increase in cost due to a complicated configuration.

The characteristic configuration of the work vehicle according to the present invention is:
Engine,
An intake passage through which combustion air flows from the outside air inlet toward the engine;
An air cleaner for removing dust contained in the combustion air;
A throttle valve for adjusting an intake amount of the combustion air by the engine;
A blow-by gas reduction passage for reducing the blow-by gas discharged from the engine to a middle portion of the intake passage;
The blow-by gas reduction passage is connected to the lower side in the flow direction than the air cleaner of the intake passage,
The lower part in the flow direction of the reduction passage connecting part to which the blow-by gas reduction passage of the intake passage is connected has a downwardly inclined posture so that the lower side in the flow direction is positioned lower, and the drainage part at the lowermost end part An inclined path section with
The throttle valve is provided on the lower side in the flow direction of the inclined path portion and at a position substantially the same as or higher than the connection position of the reduction passage.

  According to the present invention, the moisture contained in the blow-by gas that is reduced to the intake passage through the blow-by gas reduction passage is in the inclined path portion that is located on the lower side in the flow direction of the reduction passage connection portion to which the blow-by gas reduction passage is connected. Then, the flow is guided downward, that is, toward the lower side in the flow direction. And it is discharged | emitted from the drain part provided in the lowest end part to the exterior of an intake passage. Further, the blow-by gas reduction position and the throttle valve can be separated by an amount corresponding to the inclined path portion provided between the blow-by gas reduction passage and the throttle valve.

  Accordingly, it is possible to prevent moisture from entering the throttle valve and avoid disadvantages such as moisture adhering to the throttle valve and freezing even when used in cold regions.

  In the present invention, it is preferable that a resonator is provided on the downstream side in the flow direction with respect to the lowermost end portion of the inclined path portion.

  According to this configuration, by providing the resonator, the noise generated by the intake action can be suppressed to a low level. The resonator is silenced by a resonance action, and its inside is formed in a hollow shape. By providing a resonator on the lower side in the flow direction than the lowermost end portion of the inclined path portion, moisture remaining without being discharged from the discharge portion can be temporarily stored in the resonator and enter the throttle valve. Can be prevented.

1 is an overall side view of a multipurpose vehicle. 1 is an overall plan view of a multipurpose vehicle. It is a top view of a drive part. It is a side view of an intake device.

Hereinafter, an example of an embodiment according to the work vehicle of the present invention will be described with reference to the drawings.
In the description of the present embodiment, the front-rear direction and the left-right direction are described as follows unless otherwise specified. That is, the direction indicated by the arrow F in FIGS. 1 to 4 is “front”, the direction indicated by the arrow B in FIGS. 1 to 4 is “rear”, the direction indicated by the arrow R in FIGS. The direction indicated by the arrow L in 2 and 3 is “left”.

〔overall structure〕
1 and 2 show a multipurpose vehicle as an example of a work vehicle. This multi-purpose vehicle is a vehicle that is used for multi-purpose applications such as cargo transportation and recreation. The multipurpose vehicle is provided with a pair of left and right front wheels 1 that can be steered and driven, and a pair of right and left rear wheels 2 that can be driven. A driving unit 3 is provided at the front and rear center of the vehicle body. A loading platform 4 is provided behind the operation unit 3. A driving portion 5 is provided below the loading platform 4. A bonnet 6 that can be opened and closed is provided in front of the driving unit 3. An engine cooling radiator 8 and the like are disposed in the space inside the bonnet 6.

  The driver 3 is provided with a driver seat 9 on which a driver sits, an auxiliary seat 10 on which a passenger can sit, a steering wheel 11 for performing a steering operation, and a gear shifting operation. The shift lever 12 is provided. The steering wheel 11 and the speed change lever 12 are disposed on a driving panel 13 positioned in front of the driver seat 9.

  The loading platform 4 is configured to be switchable between a loading state in which a load can be placed and a dumping state in which the load can be discharged. The loading platform 4 can be in a dumped state in which the front end portion is raised by swinging around the horizontal axis so that the load can be discharged from the rear end side. The state change of the loading platform 4 can be performed, for example, by driving a hydraulic actuator.

  As shown in FIG. 1, the prime mover 5 houses a water-cooled gasoline engine 14 (hereinafter referred to as an engine), a transmission case 16 that houses a belt-type continuously variable transmission mechanism 15, and a gear-type transmission mechanism 17. A mission case 18 and the like are provided.

  As shown in FIG. 4, the engine 14 is arranged so that the crankshaft is along the left-right direction of the vehicle body and the cylinder head 19 is in an obliquely backward inclined posture. The engine 14 is configured as a two-cylinder type. The transmission case 16 is connected and supported on the side of the engine 14 and the transmission case 18. The transmission case 18 is connected and supported on the rear side of the engine 14.

  The engine 14, the transmission case 18, etc. are supported by the body frame 20. Although not described in detail, the vehicle body frame 20 is configured in a frame shape including a plurality of frame bodies extending in the front-rear direction and a plurality of frame bodies extending in the lateral direction.

  The prime mover 5 is provided with an intake device 21 that introduces external air into the engine 14 and an exhaust device 22 that exhausts exhaust from the engine 14. As shown in FIG. 2, the intake device 21 and the exhaust device 22 are arranged separately on the left and right sides.

  The exhaust device 22 includes an exhaust pipe 23 through which exhaust exhausted from the engine 14 flows, and a muffler 24 that can reduce exhaust noise. The exhaust pipe 23 extends from the engine 14 toward the front of the body and then bends, bypasses the side of the engine 14 and extends toward the rear of the body. The exhaust pipe 23 is disposed so as to pass above the transmission case 16. Two exhaust pipes 23 are extended from the rear end of the engine 14, joined at the front end of the muffler 24, and then connected to the muffler 24. Exhaust gas whose exhaust noise has been reduced by the muffler 24 is discharged outward from an exhaust port 25 at the rear of the vehicle body.

[Intake device]
Next, the intake device 21 will be described.
As shown in FIGS. 2 to 4, the intake device 21 includes an intake pipe 27 that constitutes an intake passage 26 through which combustion air introduced into the engine 14 flows, an air cleaner 28 that removes dust from the air, an intake air Resonator 29 that silences the sound, throttle valve 30 that changes and adjusts the supply amount of combustion air to the engine 14, an intake branch section 31 that branches the intake passage 26 to each cylinder of the engine 14, and blow-by gas discharged from the engine 14 Is provided with a blow-by gas reduction passage 32 or the like for returning the air to the middle of the intake passage 26.

  As shown in FIG. 2, the intake pipe 27 extends in the front-rear direction from the vehicle body front side to the vehicle body rear end. An end portion of the intake pipe 27 on the vehicle body front side is located in a space inside the bonnet 6, and an outside air intake port 33 for taking in air from the outside is formed at this end portion. The intake pipe 27 extends rearward from the outside air intake port 33, passes through the space inside the bonnet 6 and the lower part of the operating unit 3, and extends to the air cleaner 28, and from the air cleaner 28 to the rear end of the vehicle body. An intermediate intake portion 27 </ b> B extending to the located resonator 29 and an engine intake portion 27 </ b> C extending from the resonator 29 to the intake inlet 34 of the engine 14 are provided.

  The air cleaner 28 is located in the prime mover 5 on the right lateral side of the upper portion of the engine 14 and is arranged in a state where the longitudinal direction of the air cleaner 28 is along the left-right direction of the vehicle body. The air cleaner 28 is supported by a bracket 35. Although not described in detail, the bracket 35 is supported by the vehicle body frame 20.

  As shown in FIG. 4, the intermediate intake portion 27 </ b> B of the intake pipe 27 is provided with an inclined path portion 36 that is in a downward inclined posture so as to be positioned at a lower position on the lower side in the flow direction. A drainage portion 37 that discharges moisture present inside the intake pipe 27 to the outside is provided at the lowermost end portion of the inclined path portion 36. A lowermost end portion of the inclined path portion 36 is connected to a lower end side portion of the resonator 29.

  An engine side intake portion 27 </ b> C of the intake pipe 27 is connected to an upper portion of the resonator 29. The engine side intake portion 27C is provided with a throttle valve 30 on the upper side in the flow direction, and an intake branch portion 31 on the lower side in the flow direction. The connection location to the resonator 29 and the intake inlet 65 of the engine 14 are set to substantially the same height, and the engine-side intake portion 27C extends in the front-rear direction in a substantially horizontal posture.

  The intake branch section 31 passes through the air cleaner 28 and is purified, and then the air supplied in a state in which the intake air amount is adjusted by the throttle valve 30 is branched into two systems to each cylinder of the engine 14. Supply to the combustion chamber.

  The blow-by gas reduction passage 32 is connected to the lower side in the flow direction than the air cleaner 28 and to the upper side in the flow direction from the inclined path portion 36 in the intermediate side intake portion 27B of the intake pipe 27. A location where the blow-by gas reduction passage 32 is connected to the intermediate intake portion 27 </ b> B of the intake pipe 27 is supported by the engine 14 via a bracket 38. That is, as shown in FIG. 4, the support member 39 is fixed to the rear portion of the engine 14, and the support member 39 extends rearward. A bracket 38 is connected to a rear upper side portion of the support member 39, and an upper portion of the bracket 38 is connected to a flange portion 40 provided in an intermediate intake portion 27 </ b> B of the intake pipe 27.

  The blow-by gas leaking into the crankcase from the gap between the piston and the cylinder (cylinder) of the engine 14 is reduced into the intake passage 26 through the blow-by gas reduction passage 32 and supplied again to the engine 14 through the intake passage 26. Burns in the combustion chamber.

  As shown in FIGS. 3 and 4, since the inclined path portion 36 is provided at the lower side in the flow direction of the reduction passage connecting portion Q to which the blowby gas reduction passage 32 is connected in the intake passage 26, it is included in the blowby gas. The water is guided down the inclined path portion 36 and is discharged to the outside from the drainage portion 37 at the lowermost end. Further, since the reduction passage connection point Q and the throttle valve 30 are separated from each other, there is little possibility that moisture contained in the blow-by gas enters the throttle valve 30.

[Another embodiment]
(1) In the above embodiment, the resonator 29 is connected to the lowermost end portion of the inclined path portion 36. However, instead of this configuration, the resonator 29 is provided on the upstream side of the inclined path portion 36. Alternatively, it may be provided upstream of the air cleaner 28. Moreover, it is good also as a structure which is not provided with such a resonator 29. FIG.

(2) In the above embodiment, the air cleaner 28 is arranged such that the longitudinal direction of the air cleaner 28 is along the lateral direction of the vehicle body. However, instead of this configuration, the longitudinal direction of the air cleaner 28 is the longitudinal direction of the body. It may be arranged along.

(3) In the above embodiment, the outside air intake port 33 of the intake pipe 27 is illustrated in the space formed in the bonnet 6, but instead of this configuration, for example, the intake pipe 27 outside air intake ports 33 may be located at locations where air containing relatively little dust is present, such as a rear portion of the driver seat 9 of the driver 3.

(4) In the above embodiment, the power source provided with the gasoline engine 14 is shown. However, instead of this configuration, a configuration including a diesel engine may be used, or a configuration using both the engine and the electric motor for traveling may be used. Alternatively, a configuration including only an electric motor may be used.

(5) In the above embodiment, the belt-type continuously variable transmission mechanism 15 is exemplified, but instead of this configuration, for example, instead of the belt-type continuously variable transmission mechanism 15, a hydrostatic type A continuously variable transmission may be provided.

(6) In the above-described embodiment, a configuration in which two people can get on the driving unit is possible, but a configuration in which three or more people can get on is also possible.

  The present invention can be applied to a work vehicle equipped with an engine.

14 Engine 26 Air intake passage 28 Air cleaner 29 Resonator 30 Throttle valve 32 Blow-by gas reduction passage 33 Outside air intake 36 Inclined passage portion 37 Drainage portion Q Reduction passage connection point

Claims (2)

Engine,
An intake passage through which combustion air flows from the outside air inlet toward the engine;
An air cleaner for removing dust contained in the combustion air;
A throttle valve for adjusting an intake amount of the combustion air by the engine;
A blow-by gas reduction passage for reducing the blow-by gas discharged from the engine to a middle portion of the intake passage;
The blow-by gas reduction passage is connected to the lower side in the flow direction than the air cleaner of the intake passage,
The lower part of the flow direction of the intake passage connected to the blow-by gas return passage of the intake passage is inclined downward so as to be positioned at a lower position in the lower direction of the flow direction, and a drainage portion at the lowermost end. An inclined path section with
A work vehicle in which the throttle valve is provided at a position on the lower side in the flow direction of the inclined path portion and at a position substantially the same as or higher than the connection position of the return path.   The work vehicle according to claim 1, wherein a resonator is provided on a lower side in the flow direction than a lowermost end portion of the inclined path portion.

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