JP2012136083A - Tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tractor 100 that is capable of preventing the decrease in the efficiency of cooling a heat exchanger.SOLUTION: The tractor includes: an engine room 20 surrounded by a hood 8 having an outside air inlet 8a in a front end; a plurality of heat exchangers 30 disposed in the engine room 20 between the outside air inlet 8a and an engine 2 arranged at the rear of the engine room 20; and a shielding plate 28 disposed below the plurality of heat exchangers 30 so as to cover all lower surfaces of the engine room 20 in the front more than the engine 2.

Description

  The present invention relates to a tractor, and more particularly, to an arrangement of a heat exchanger such as an intercooler or an oil cooler.

  Conventionally, a tractor in which a cooling fan and a radiator for cooling engine cooling water are arranged in front of an engine room in which the engine is housed is known. In such a tractor, a heat exchanger such as an intercooler that cools air compressed by an engine supercharger or an oil cooler that cools hydraulic oil of a hydraulic device is accommodated in an engine room. For example, it is like patent document 1.

  The tractor of Patent Document 1 is configured to be hollow so that the lower part of the front frame that holds the equipment in the engine room communicates with the outside, and an oil cooler is disposed below the radiator and inside the front frame. Yes. As a result, the outside air sucked by the cooling fan passes through the oil cooler as cooling air and is then discharged out of the engine room through the cavity at the lower part of the front frame.

  However, in the technique of Patent Document 1, since the lower surface of the engine room communicates with the outside, depending on the operating state of the tractor, the cooling air heated by passing through a radiator and a heat exchanger such as an oil cooler again There is a case where it flows back into the engine room. Therefore, there has been a problem that the cooling efficiency of the heat exchanger decreases.

JP 2001-163064 A

  This invention is made | formed in view of the subject which concerns, and it aims at provision of the tractor which can prevent the fall of the cooling efficiency of a heat exchanger.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, the engine room surrounded by a bonnet having an outside air introduction port at the front end portion, and the engine room, which is located in the engine room and disposed behind the outside air introduction port and the engine room. A plurality of heat exchangers, and a shielding plate disposed below the plurality of heat exchangers so as to cover all lower surfaces of the engine room ahead of the engine.

  3. The heat exchanger according to claim 2, wherein the plurality of heat exchangers are arranged so that a radiator disposed in front of the engine, an intercooler disposed in front of the radiator, and the intercooler are arranged vertically below the intercooler. And an oil cooler for a hydraulic continuously variable transmission.

  According to a third aspect of the present invention, an auxiliary outside air inlet is formed in the vicinity of the outside air inlet in the shielding plate.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, since the lower part of the plurality of heat exchangers is shielded by the shielding plate, the engine air or the cooling air discharged to the outside after being heated by cooling the heat exchanger , It does not flow into the engine room again from below the engine room. Thereby, it can prevent that the cooling efficiency of a heat exchanger falls.

  In claim 2, the intercooler as the heat exchanger and the oil cooler for the hydraulic continuously variable transmission are arranged side by side so as to overlap in the flow direction of the outside air sucked from the outside air inlet. The number of heat exchangers to be arranged is reduced, and the number of heat exchangers through which outside air passes as cooling air can be reduced. Thereby, it can prevent that the cooling efficiency of a heat exchanger falls.

  In Claim 3, the auxiliary | assistant external air introduction port is formed in the position close | similar to the oil cooler for hydraulic continuously variable transmissions arrange | positioned under the intercooler, and the thermal radiation efficiency of the radiator 31 located in the backmost surface is improved. be able to. Thereby, it can prevent that the cooling efficiency of a heat exchanger falls.

The side view which showed the whole structure of the tractor which concerns on one Embodiment of this invention. Schematic which shows the structure of the hydraulic continuously variable transmission which is the continuously variable transmission of the tractor which concerns on one Embodiment of this invention. The perspective view which shows the inside of the engine room of the tractor which concerns on one Embodiment of this invention. Schematic which shows the connection of the several heat exchanger of the tractor which concerns on one Embodiment of this invention. The perspective view which shows the flow of the cooling air in the engine room of the tractor which concerns on one Embodiment of this invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

First, the whole structure of the tractor 100 which is one Embodiment of the working vehicle which concerns on this invention is demonstrated using FIG.1 and FIG.2.
In the following description, the front / rear / left / right / up / down directions are defined with the arrow X direction as the forward direction of the tractor 100 and the arrow Y direction as the left direction of the tractor 100.

The tractor 100 is equipped with various work machines (such as a rotary) and performs various work using the worn work machines.
As shown in FIG. 1, a tractor 100 is configured such that a body frame 1 is arranged with a longitudinal direction as a longitudinal direction, and is connected to an engine 2 at a rear portion thereof. A transmission case 9 that houses a part of the power transmission mechanism of the tractor 100 is connected to the rear portion of the engine 2 with the longitudinal direction being the front-rear direction. The front part of the body frame 1 is supported by a pair of left and right front wheels 4 via a front axle, and the rear part of the transmission case 9 is supported by a pair of left and right rear wheels 5 via a rear axle.

  Then, after the power of the engine 2 is shifted by the power transmission mechanism, it can be transmitted to a work implement such as a tillage device (not shown) mounted on the transmission case 9 via the work implement mounting device 3. Further, hydraulic oil pumped by a hydraulic pump (not shown) driven by the power of the engine 2 is supplied to a work machine such as a front loader (not shown) mounted on the body frame 1 and the transmission case 9 and the work machine mounting device 3. It is possible. In this way, various working machines are driven by transmitting the power of the engine 2.

  Further, after the power of the engine 2 is shifted by the power transmission mechanism, it can be transmitted to the pair of left and right front wheels 4 via the front axle, and can be transmitted to the pair of left and right rear wheels 5 via the rear axle. Is done. When the power of the engine 2 is transmitted, the pair of left and right front wheels 4 and the pair of left and right rear wheels 5 are rotationally driven, and the tractor 100 travels.

  In the upper part of the transmission case 9, a driving operation unit 6 is provided for an operator to get on and operate the tractor 100, and is covered with the cabin 7. Further, an engine room 20 covered with a hood 8 having an outside air inlet 8a at the front end and an outlet 8b on both sides of the rear is formed in front of the cabin 7. In the engine room 20, the engine 2, a plurality of heat exchangers 30 and the like are arranged.

  Hereinafter, the transmission case 9 and the hydraulic continuously variable transmission (hereinafter simply referred to as “HST10”) 10 will be described with reference to FIG.

  The transmission case 9 is configured by connecting a plurality of substantially cylindrical members having a rectangular cross section. The transmission case 9 is arranged with its longitudinal direction as the front-rear direction (see FIG. 1).

  As shown in FIG. 2, the HST 10 forms a part of the power transmission mechanism and continuously changes the rotational power generated by the engine 2. The HST 10 is disposed in the transmission case 9. The HST 10 mainly includes a pump input shaft 11, a charge pump 12, a variable displacement hydraulic pump 13, a closed circuit oil passage 14, a fixed displacement hydraulic motor 15, a motor output shaft 16, an actuator 17, and the like. However, the hydraulic motor 15 may be a variable displacement type, and the movable swash plate of the hydraulic motor 15 or the movable swash plate of both the hydraulic pump 13 and the hydraulic motor 15 may be controlled.

  The pump input shaft 11 transmits the rotational power of the flywheel 21 rotated by the engine 2. One end of the pump input shaft 11 is linked to the flywheel 21.

  The charge pump 12 supplies hydraulic oil. The charge pump 12 is interlocked with the other end of the pump input shaft 11. The rotational power of the flywheel 21 is transmitted to the charge pump 12 via the pump input shaft 11. The charge pump 12 is rotated by the rotational power transmitted by the pump input shaft 11, and supplies hydraulic oil in the transmission case 9, which also serves as an oil tank, to the closed circuit oil passage 14.

The hydraulic pump 13 discharges hydraulic oil. The other end of the pump input shaft 11 is linked to the hydraulic pump 13 via the charge pump 12. The rotational power of the flywheel 21 is transmitted to the hydraulic pump 13 via the pump input shaft 11. The hydraulic pump 13 is rotated by the rotational power transmitted by the pump input shaft 11 and discharges hydraulic oil.
The hydraulic pump 13 includes a movable swash plate 13a. By adjusting the inclination angle of the movable swash plate 13a by the actuator 17, the discharge amount and the discharge direction of the hydraulic oil can be changed.

  The closed circuit oil passage 14 guides the hydraulic oil discharged by the hydraulic pump 13. The closed circuit oil passage 14 is connected in communication with the charge pump 12 and the hydraulic pump 13. The closed circuit oil passage 14 includes a neutral valve 14 a and a high-pressure relief valve 14 b, and hydraulic oil is supplied from the oil tank 19 by the charge pump 12.

  The hydraulic motor 15 is rotated by hydraulic fluid that is pumped. The hydraulic motor 15 is connected in communication with the closed circuit oil passage 14. The hydraulic motor 15 is rotated by the hydraulic oil guided by the closed circuit oil passage 14. In other words, the power output from the hydraulic pump 13 is transmitted to the hydraulic motor 15 by the hydraulic oil pumped through the closed circuit oil passage 14.

  The motor output shaft 16 transmits the rotational power of the hydraulic motor 15. One end of the motor output shaft 16 is linked to the hydraulic motor 15, and the other end of the motor output shaft 16 is linked to the differential device 5a. The rotational power of the hydraulic motor 15 is transmitted to the differential device 5a via the motor output shaft 16. The transmitted rotational power is distributed to the left and right by the differential 5a and transmitted to the pair of left and right rear wheels 5 through the rear axle.

  The HST 10 changes the traveling speed and the traveling direction of the tractor 100 by adjusting the rotation speed and the rotation direction of the hydraulic motor 15 by operating the actuator 17 by the operation tool 6 a provided in the driving operation unit 6. be able to. In this embodiment, the HST 10 is adjusted by the actuator 17, but is not limited to this, and may be configured to be operated by the operation tool 6 a connected to the HST 10 via a wire or a lever. Good. Further, the hydraulic continuously variable transmission is not limited to the HST, and any hydraulic transmission may be used as long as it has a configuration for transmitting power via hydraulic pressure.

  Below, the cooling fan 22, the several heat exchanger 30, the shielding board 28, etc. which are arrange | positioned in the engine room 20 are demonstrated using FIG.3 and FIG.4.

  As shown in FIG. 3, the cooling fan 22 as a blower sucks outside air into the engine room 20 as cooling air, and cools the heat exchanger 30 and the engine 2 to the outside of the engine room 20. To be discharged. The cooling fan 22 is rotatably supported in front of the engine 2 so as to blow in the direction of the engine 2. The cooling fan 22 is driven by rotational power from the crankshaft of the engine 2. The cooling fan 22 sucks outside air from the outside air inlet 8 a of the bonnet 8 as cooling air, and discharges the cooling air from the discharge port 8 b formed in the hood 8 on the left and right sides of the engine 2 and from below the body frame 1. Arranged as possible.

  The plurality of heat exchangers 30 are disposed on the upper side of the body frame 1 in front of the engine 2 in the engine room 20. The plurality of heat exchangers 30 include a radiator 31, an intercooler 32, and HST oil coolers 33 and 33 that are oil coolers for a hydraulic continuously variable transmission.

The radiator 31 cools the circulating cooling water of the engine 2 and has a substantially rectangular parallelepiped shape. The radiator 31 is disposed in front of the cooling fan 22 so that the heat dissipation surface faces the cooling fan 22 in close proximity.
As shown in FIG. 4, the radiator 31 is connected to a water jacket 2 a of the engine 2 disposed behind the radiator 31 via a cooling water pipe 23 so that the cooling water can be circulated between the radiator 31 and the engine 2. Composed.

As shown in FIGS. 3 and 4, the intercooler 32 cools the intake air compressed by the supercharger 24 attached to the engine 2. The intercooler 32 is configured in a substantially rectangular parallelepiped shape in which the vertical width is set to substantially half the vertical width of the radiator 31. The intercooler 32 is disposed above the engine room 20 so that the rear heat dissipation surface faces the front heat dissipation surface of the radiator 31. A substantially cylindrical air filter 27 through which the engine 2 sucks outside air is disposed in front of the intercooler 32.
As shown in FIG. 4, the intercooler 32 is connected to the intake manifold 25 of the engine 2 and the supercharger 24 via the intake pipe 26. That is, the intercooler 32 is connected between the intake manifold 25 and the compressor of the supercharger 24 via the intake pipe 26.

As shown in FIG. 3, the HST oil coolers 33 and 33 cool the hydraulic oil of the HST 10. The HST oil coolers 33 and 33 are configured in a substantially rectangular parallelepiped shape in which the vertical width is set to approximately half the vertical width of the radiator 31. The HST oil coolers 33 and 33 are arranged in the engine room 20 such that the rear heat radiation surface faces the front heat radiation surface of the radiator 31. In order to improve the cooling efficiency, the HST oil coolers 33 and 33 are arranged such that a plurality (two in this embodiment) of the HST oil coolers 33 face each other in the front-rear direction. The HST oil coolers 33 and 33 do not overlap with the intercooler 32 which is another heat exchanger in the flow direction of the outside air sucked into the engine room 20 as cooling air (in a side view of the engine room 20). It is arranged below the intercooler 32. Strictly speaking, the HST oil coolers 33 and 33 are arranged so that the cooling air passage portions thereof do not overlap the cooling air passage portions of the intercooler 32.
As shown in FIG. 4, the HST oil coolers 33 and 33 are connected to the HST 10 (transmission case 9) via an oil supply pipe 18.
The capacities of the HST oil coolers 33 and 33 and the intercooler 32 are determined by the output of the engine 2 and the amount of hydraulic oil used. Is achieved.

  The shielding plate 28 shields the outside air flowing into the engine room 20 from below the body frame 1. The shielding plate 28 is formed of a plate-like member, and is arranged in close contact with the upper side of the body frame 1 with the plate surface as the vertical direction. The shield plate 28 is formed in substantially the same shape as the lower surface opening of the bonnet 8 when viewed from above, and is configured to cover the entire lower surface of the engine room 20 ahead of the radiator 31. On the other hand, a battery storage portion 29 is formed at the front end of the machine body frame 1 and is formed in a box shape having an upper surface opened to store the battery 29b. Therefore, a battery housing hole 28 a is formed in a portion of the shielding plate 28 that overlaps the opening of the battery housing portion 29.

  The front-rear direction of the opening portion of the battery storage unit 29 is configured to be larger than the front-rear direction width of the battery 29 b. Therefore, by placing the battery 29b behind the battery housing hole 28a and placing it in the battery housing portion 29, a gap is formed in the battery housing portion 29 in front of the battery 29b. In addition, a through-hole 29a is formed in front of the bottom surface of the battery storage unit 29 so as to communicate with the outside of the apparatus. Thus, the shielding plate 28 is configured to be able to flow into the engine room 20 using the gap in front of the battery 29b in the battery housing hole 28a as the auxiliary outside air introduction port 28b and the outside air flowing from the through hole 29a as the cooling air.

  Next, the mode of the cooling air flow will be described with reference to FIG.

  As shown in FIG. 5, when the cooling fan 22 is rotationally driven by the rotational power from the engine 2, the outside air is introduced from the outside of the machine into the engine room 20 by the cooling fan 22, and the shielding plate The air is sucked through 28 auxiliary outside air inlets 28b (see white arrow A). The outside air flowing into the engine room 20 flows as cooling air toward the cooling fan 22 behind the engine room 20.

  In the engine room 20, a part of the cooling air flows from the outside air inlet 8 a and bypasses the air filter 27, passes through the intercooler 32 (see white arrow B), and then passes through the radiator 31. A part of the cooling air flows from the outside air introduction port 8a and bypasses the air filter 27, passes through the HST oil coolers 33 and 33 (see white arrow C), and then passes through the radiator 31. Further, the cooling air flowing in from the through hole 29a on the bottom surface of the battery housing portion 29 mainly passes through the HST oil coolers 33 and 33 so as to bypass the battery from the auxiliary outside air introduction port 28b (see white arrow D). ) And then passes through the radiator 31.

  At this time, as described above, the intercooler 32 and the HST oil coolers 33 and 33 are arranged vertically so as not to overlap each other. Accordingly, most of the cooling air flowing into the engine room 20 passes through the radiator 31 after passing through either the intercooler 32 or the HST oil coolers 33 and 33. That is, the cooling air that has flowed into the engine room 20 does not pass through both the intercooler 32 and the HST oil coolers 33 and 33 to reach the radiator 31. That is, the cooling air that has passed through the intercooler 32 and has been warmed by heat exchange does not pass through the radiator 31 after having passed through the HST oil coolers 33 and 33 and has been further warmed by heat exchange.

  In addition, since the intercooler 32 and the HST oil coolers 33 and 33 are arranged so as not to overlap each other in the flow direction of the cooling air, the passage resistance of the cooling air passing through the engine room 20 is reduced in the engine room 20. It is substantially the same regardless of the position, and the flow of cooling air does not concentrate on a specific part.

  After passing through the intercooler 32 or the HST oil coolers 33 and 33 in the engine room 20, the cooling air heated to a high temperature by passing through the radiator 31 flows to the rear side of the engine 2, (Refer to the gray arrow E) or the discharge port 8b (refer to the gray arrow F) of the bonnet 8 to the outside of the machine. At this time, the cooling air flowing below the engine 2 is shielded by the shielding plate 28 even if it flows into the engine room 20 from below the body frame 1.

  As described above, the engine room 20 surrounded by the bonnet 8 having the outside air introduction port 8 a at the front end, and the engine 2 located between the outside air introduction port 8 a and the engine room 20 in the engine room 20. A plurality of heat exchangers 30, and a shielding plate 28 disposed below the plurality of heat exchangers 30 so as to cover the entire lower surface of the engine room 20 in front of the engine 2. is there.

  With this configuration, since the lower portions of the plurality of heat exchangers 30 are shielded by the shielding plate 28, the temperature of the engine 2 is increased after cooling the hot air of the engine 2 or cooling the plurality of heat exchangers 30. The cooling air discharged outside does not flow into the engine room 20 again from below the engine room 20. Thereby, it can prevent that the cooling efficiency of the several heat exchanger 30 falls.

  In addition, the plurality of heat exchangers 30 are disposed so as to be lined up and down with the intercooler 32 below the intercooler 32, the radiator 31 disposed in front of the engine 2, the intercooler 32 disposed in front of the radiator 31. The HST oil coolers 33 and 33, which are oil coolers for a hydraulic continuously variable transmission, are configured.

  By configuring in this way, the intercooler 32 that is a heat exchanger and the HST oil coolers 33 and 33 are arranged side by side so as to overlap in the flow direction of the outside air sucked from the outside air inlet 8a. Thus, the number of heat exchangers arranged can be reduced, and the number of heat exchangers through which outside air passes as cooling air can be reduced. Thereby, it can prevent that the cooling efficiency of the several heat exchanger 30 falls.

  The shielding plate 28 is formed with an auxiliary outside air introduction port 28b in the vicinity of the outside air introduction port 8a.

  By configuring in this way, by forming the auxiliary outside air inlet 28b at a position close to the HST oil coolers 33, 33 disposed below the intercooler 32, the heat radiation efficiency of the radiator 31 located at the rearmost surface is improved. Can be improved. Thereby, it can prevent that the cooling efficiency of the several heat exchanger 30 falls.

2 Engine 8 Bonnet 8a Outside air inlet 20 Engine room 28 Shield plate 30 Multiple heat exchangers 100 Tractor

Claims (3)

An engine room surrounded by a hood having an outside air inlet at the front end;
A plurality of heat exchangers disposed in the engine room between the outside air inlet and an engine disposed behind the engine room;
A tractor comprising: a shielding plate disposed below the plurality of heat exchangers so as to cover the entire lower surface of the engine room ahead of the engine. The plurality of heat exchangers are:
A radiator disposed in front of the engine;
An intercooler disposed in front of the radiator;
The tractor according to claim 1, comprising: an oil cooler for a hydraulic continuously variable transmission disposed below the intercooler so as to line up with the intercooler. In the shielding plate,
The tractor according to claim 1 or 2, wherein an auxiliary outside air introduction port is formed in the vicinity of the outside air introduction port.

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