JP2022047181A - Work vehicle - Google Patents

Abstract

To provide a work vehicle which enables a drive oil pressure of a hydraulic pump provided near an engine to be transmitted to an oil pressure steering mechanism with a hydraulic circuit rationally connected by pipes to conduct maneuvering safely and securely.SOLUTION: In the work vehicle, an engine 4 is mounted at front parts of vehicle body frames 13, 13 and front wheels 2, 2 are steered by a steering handle 9 erected rearward of the engine 4. Left and right oil pipes 17L, 17R extend from an orbit roll 20 provided at a lower end of the steering handle 9, pass through a guide hole 13H provided at the vehicle body frame 13 via a pipe receiver 18 provided at a side part of the vehicle body frame 13, and are connected to a steering cylinder 62 provided at a lower part of the engine 4.SELECTED DRAWING: Figure 11

Description

The present invention relates to a hydraulic steering device for a work vehicle such as a tractor.

For example, as described in Japanese Patent Application Laid-Open No. 8-230699, the work vehicle is provided with a cockpit in the substantially center of the machine body, and the engine mounted on the front part of the machine body drives the work machine mounted on the front and rear wheels and the rear part of the machine body. By rotating the steering wheel provided in front of the cockpit, the steering mechanism of the front wheels is operated by the hydraulic pressure driven by the engine to steer.

Japanese Unexamined Patent Publication No. 8-230699

The hydraulic steering device in the tractor described in Japanese Patent Application Laid-Open No. 8-230699 operates by supplying the hydraulic pressure generated by the hydraulic pump attached to the engine from the orbit roll at the lower end of the steering to the steering cylinders of the left and right front wheels by hydraulic piping. Although it operates in a turning motion, it is difficult to pipe it safely and easily because it is hydraulically piped to the steering cylinder installed at the bottom of the engine, which gets hot.

An object of the present invention is to provide a work vehicle capable of safe and reliable maneuvering operation by transmitting to a hydraulic steering mechanism by a hydraulic circuit in which the drive hydraulic pressure of a hydraulic pump provided near the engine is rationally piped.

The above-mentioned problem of the present invention is solved by the following technical means.

The invention of claim 1 is in a work vehicle in which an engine 4 is mounted on the front portions of vehicle body frames 13 and 13 and the front wheels 2 and 2 are steered by a steering handle 9 standing at the rear portion of the engine 4. Left and right oil pipes 17L and 17R are connected to the steering cylinder 62 provided at the bottom of the engine 4 through the guide hole 13H provided at the vehicle body frame 13 via the pipe receiver 18 provided at the side of the vehicle body frame 13 from the orbit roll 20 provided at the lower end of the engine 4. It is a work vehicle made up of connecting pipes.

The invention according to claim 1 comprises providing a pipe cover 19 in front of the pipe receiver 18, passing the left and right oil pipes 17L and 17R through the guide holes 13H of the vehicle body frame 13 from the front end of the pipe receiver 18 under the pipe cover 19. The work vehicle described.

The invention according to claim 3 is the work vehicle according to claim 1, wherein the left and right oil pipes 17L and 17R are connected to the steering cylinder 62 through under the belt cover 22 covering the transmission belt to the air-cooled fan of the engine 4.

In the invention of claim 4, a heat source cover 23 that covers the heat source of the engine 4 is provided at the rear of the belt cover 22, and a heater hose 24 that sends hot water from the radiator 42 to the air conditioner is piped through the belt cover 22 and the side portions of the heat source cover 23. The work vehicle according to claim 1, which is started up at the rear of the receiver 18.

In the invention of claim 1, the left and right oil pipes 17L and 17R piped from the orbit roll 20 that opens and closes the valve by the rotation of the steering handle 9 to the steering cylinder 62 are passed over the pipe receiver 18 provided on the side portion of the vehicle body frame 13 to pass the vehicle body frame. Since it is connected to the steering cylinder 62 at the bottom of the engine 4 through the guide hole 13H of 13, it is not affected by the heat of the engine 4.

According to the second aspect of the present invention, the heat influence of the engine 4 is reduced by allowing the left and right oil pipes 17L and 17R to pass from the pipe receiver 18 to the lower side of the pipe cover 19.

According to the third aspect of the present invention, even if the transmission belt transmitted to the air-cooled fan of the engine 4 becomes loose, it is safe to prevent the belt cover 22 from coming into contact with the left and right oil pipes 17L and 17R connected to the steering cylinder 62.

According to the fourth aspect of the present invention, the heater hose 24 that sends hot water from the radiator 42 to the air conditioner is protected by the belt cover 22 and the heat source cover 23 and is connected to the air conditioner at the rear of the pipe receiver 18, so that the air conditioner operates reliably without any trouble.

It is a side view of the tractor which is a work vehicle which concerns on embodiment of this invention. It is explanatory drawing which shows the front area of the engine room of the tractor. It is explanatory drawing which shows the front area of the engine room in the state which the battery of the tractor is removed. It is explanatory drawing which shows the arrangement state of the hose which connects a cooler of the tractor and an engine. It is explanatory drawing which shows the arrangement state of the hose in the vicinity of the steering cylinder of the tractor. It is explanatory drawing which looked at the engine room of the tractor from diagonally below. It is a right side view in the engine room where a part of the tractor is omitted. It is explanatory drawing which shows an example of the harness wiring structure on the left side of the engine of the tractor. It is explanatory drawing of the harness guide which guides the harness of the tractor. It is explanatory drawing which shows the state which attached the cover to the EGR apparatus of the tractor. It is the upper right enlarged perspective view of the rear part of the engine of the tractor. It is a lower right perspective view of the engine of the tractor. It is the upper right perspective view of the rear part of the engine of the tractor. It is a right enlarged perspective view of the engine of the tractor.

Hereinafter, embodiments of the work vehicle disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

First, the overall configuration of the tractor, which is the work vehicle according to the embodiment, will be described with reference to FIG. FIG. 1 is a side view of the tractor.

A tractor is an agricultural tractor that works while running on its own in a field or the like. Further, the tractor can perform a predetermined work while the operator (also referred to as a worker) is on board and travels in the field.

In the following, the front-rear direction of the tractor refers to the straight-ahead direction of the tractor. The forward direction of the tractor is to move in the direction from the driver's seat 8 toward the steering wheel 9 in the straight direction of the tractor, and the opposite is the reverse (backward) direction. The front and rear of the tractor are based on the forward direction.

Further, the left-right direction is a direction horizontally orthogonal to the front-back direction. Here, the left and right are defined toward the "front" side in the front-rear direction. That is, when the operator arrives at the driver's seat 8 and faces forward, the left hand side is "left" and the right hand side is "right". Further, the vertical direction is a direction orthogonal to the front-rear direction and the left-right direction. Therefore, the front-back direction, the left-right direction, and the up-down direction are orthogonal to each other in three dimensions.

As shown in FIG. 1, the tractor includes a front wheel 2 and a rear wheel 3 as a drive device, and a connecting portion 7 for connecting a working machine to form a traveling vehicle body 1. Further, the traveling vehicle body 1 includes an engine 4, a bonnet 6 accommodating the engine 4, and a cabin 11 having a control unit. These are assembled on a pair of left and right body frames 13 that are the main frames of the traveling vehicle body 1. A step 12 for raising and lowering the cabin 11 is arranged between the front wheel 2 and the rear wheel 3. The bonnet 6 is provided so as to be openable and closable at the front portion of the traveling vehicle body 1, and covers the engine 4 in a closed state.

The front wheels 2 are a pair of left and right wheels, are located at the front portion of the traveling vehicle body 1, are rotatably connected to the axle 2a, and function as steering wheels. The rear wheels 3 are a pair of left and right wheels, are located at the rear of the traveling vehicle body 1, and are rotatably connected to the axle 3a.

In the present embodiment, the four-wheel drive (4WD) traveling device in which the front wheels 2 and the rear wheels 3 are both driving wheels is used, but only the rear wheels 3 may be used as driving wheels. The tractor may have a crawler-type track instead of the rear wheel 3 as a traveling device.

The engine 4 is a drive source for a tractor and is a heat engine such as a diesel engine or a gasoline engine. The power (rotational power) transmitted from the engine 4 covered by the bonnet 6 is appropriately decelerated by a transmission (transmission mechanism) (not shown) to the front wheels 2 and the rear wheels 3 and the PTO (Power Take-off) shaft (not shown). Be transmitted.

Further, as shown in FIG. 1, the cabin 11 is provided in the upper part of the traveling vehicle body 1, and the steering wheel provided inside is operated by the driver's seat 8, which is the driver's seat, or by the driver. It is equipped with a steering wheel 9 that can steer the front wheels 2. The steering handle 9 is erected on a dashboard 10 having a display unit (meter panel) for displaying various information on the upper surface. The control unit is provided with various levers such as a main shift lever, an auxiliary shift lever, a forward / backward advance lever, and an accelerator lever (not shown) in the vicinity of the steering handle 9. Further, a brake pedal, a tilt pedal, an accelerator pedal, a clutch pedal, and the like (not shown) are provided in the lower front portion of the cockpit 8.

Although the control unit of the tractor according to the present embodiment is provided in the cabin 11, it may be an open type without the cabin 11.

By the way, the engine 4 includes an EGR (Exhaust Gas Recirculation) system 5 that returns a part of the exhaust gas to the intake side of the engine 4. The EGR system 5 is provided to reduce nitrogen oxides (NOx) in the exhaust gas and improve fuel efficiency.

FIG. 2 is an explanatory view showing a front area of the engine room. Further, FIG. 3 is an explanatory diagram showing a front region of the engine room in a state where the battery 61 is removed from FIG. 2. The engine room is formed inside the bonnet 6.

As shown in FIG. 2, in the front region of the engine room, a base plate 14 is provided on a pair of left and right front and rear long vehicle body frames 13, 13, and a battery 61 and a cooler are provided on the base plate 14 from the front. The fuel cooler 15 and the condenser 41 and the radiator 42 are arranged.

The fuel cooler 15 is for cooling fuel such as light oil in order to improve the combustion state of the engine 4, and is arranged between the battery 61 and the condenser 41. The condenser 41 cools the refrigerant of an air conditioner (not shown). The radiator 42 cools the cooling water of the engine 4.

In the present embodiment, as shown in FIG. 3, as the fuel cooler 15, the first fuel cooler 151 and the second fuel cooler 152 arranged in parallel in the width direction of the machine body are provided. The first fuel cooler 151 is provided on the side where fuel is supplied to the engine 4 from a fuel tank (not shown), and the second fuel cooler 152 returns surplus fuel from the fuel supplied to the engine 4 to the fuel tank. It is located on the side.

Since the cooling mechanism has the above-mentioned layout in the front region of the engine room, the limited space in the engine room can be effectively used. Further, since the fuel cooler 15 is provided with the first fuel cooler 151 and the second fuel cooler 152, the fuel temperature can be maintained within a desired temperature range, and a predetermined fuel temperature standard can be satisfied. can.

As shown in FIG. 3, a hose insertion hole 140 is formed behind the battery mounting space in the base plate 14. That is, a plurality of hoses 16 connected to and extended to each of the first fuel cooler 151 and the second fuel cooler 152 are inserted through the hose insertion holes 140 and extended downward to the base plate 14. Then, the hose 16 is arranged toward the engine 4 side, that is, toward the rear of the machine body. In this way, the hose 16 is arranged inside the left and right body frames 13 and 13 without protruding outward.

In this way, the hose 16 extending from the fuel cooler 15 is passed through the hose insertion hole 140 and pulled out from the engine room where the temperature is high to the outside where the temperature is relatively lower than the inside of the engine room. It prevents the fuel cooled by the engine from unnecessarily rising in temperature. Further, since the hose 16 does not protrude to the outside of the vehicle body frames 13 and 13, the appearance is not impaired.

Further, the arrangement mode of the hose 16 will be described more specifically with reference to FIGS. 4 to 7. FIG. 4 is an explanatory diagram showing a wiring state of the hose 16 connecting the cooler (fuel cooler 15) and the engine 4. FIG. 5 is an explanatory diagram showing a wiring state of the hose 16 in the vicinity of the steering cylinder. Further, FIG. 6 is an explanatory view of the engine room viewed from diagonally below, and FIG. 7 is a right side view of the engine room with a part omitted.

As shown in FIG. 4, the hose 16 extending from the fuel cooler 15 passes above the reinforcing frame 130 located below the hose insertion hole 140 (see FIG. 3) and steers the front wheel 2 which is the steering wheel. The steering cylinder 62 is arranged so as to pass between the steering cylinder 62 and the crank pulley 44 provided in the engine 4. In FIGS. 4 to 7, reference numeral 43 indicates a radiator fan that is rotated via the belt by the rotation of the crank pulley 44.

A hose cover 64 is disposed between the hose 16 and the crank pulley 44. The hose cover 64 is composed of a plate spanned between the axle brackets 63 and 63 attached to the left and right vehicle body frames 13 and 13, and also functions as a reinforcing material for the axle brackets 63 and 63.

Further, as shown in FIGS. 5 and 6, a guide member 65 formed by a round bar is erected between the left and right vehicle body frames 13 and 13 so as to be located between the engine 4 and the steering cylinder 62. .. Then, the hose 16 is arranged so as to pass between the guide member 65 and the hose cover 64 (see FIG. 4).

With such a configuration, the hose 16's wiring area is limited, and the hose 16's wiring mode can be stabilized.

Further, as shown in FIGS. 4 and 7, a relay pipe 45 that relays the hose 16 and connects to the engine 4 is arranged in the lower part of the right side wall of the engine 4. The relay pipe 45 is composed of a first pipe 451 extending in a straight line and a second pipe 452 bent into a substantially L shape.

As shown in the figure, the first pipe 451 and the second pipe 452 are arranged side by side in two rows in the vertical direction with the first pipe 451 facing up.

In the present embodiment, the first fuel is attached to the other end (right end in the figure) of the first pipe 451 whose one end (left end in the figure) is connected to the fuel tank (not shown) via a fuel filter (not shown). The hose 16a connected to the IN side of the cooler 151 is connected. On the other hand, at the other end (right end in the figure) of the second pipe 452, which is located below the first pipe 451 and one end (left end in the figure) is connected to the fuel pump 48 (see FIGS. 4 and 7). , The hose 16b connected to the OUT side of the first fuel cooler 151 is connected.

Further, the first pipe 451 and the second pipe 452 are attached to the pipe support bracket 46 fixed to the side surface of the axle bracket 63. With such a configuration, it is possible to prevent interference with a working machine attached to the front side of the tractor, such as a front loader.

In this way, by using the relay pipe 45, the length of the hose 16 can be shortened, and the cost can be reduced. Further, the second pipe 452 can be composed of the same parts, and the types of parts can be reduced.

By the way, it is preferable that the first pipe 451 and the second pipe 452 are made of the same material as the fuel cooler 15. By doing so, apart from the fuel cooler 15, it is possible to contribute to lowering the temperature of the fuel even outside the engine room.

Further, the hose 16 and the relay pipe 45 connected between the fuel filter (not shown) and the fuel pump 48 (see FIGS. 4 and 7) are as low as possible than the suction port of the fuel pump 48 of the engine 4. It is desirable to arrange it so that it is in a position. It is possible to prevent the formation of air pools inside the hose 16 and the like, and to prevent rotational fluctuations when the pooled air is sucked into the injection pump.

The above-mentioned hose 16 is arranged on the right side of the engine 4, but the hoses and harnesses arranged on the left side of the engine 4 may be arranged along the axle bracket 63. When the axle bracket 63 is provided with the front loader mounting portions 49, 49 (see FIGS. 4 and 7), the wiring may be arranged below and inside the front loader mounting portions 49, 49. By arranging in this way, it is possible to stably maintain an orderly arrangement mode without getting in the way when the front loader is attached.

The hoses and harnesses described above can be arranged along a guide mounted above the front loader mounting portion, for example. In this case, it is preferable to provide a cover that covers the hoses and harnesses arranged along the guide. By pressing from the outside, it is possible to arrange the lines in an orderly manner. At this time, if the power steering hose (not shown) is routed through a hole provided on the side surface of the axle bracket 63, swelling at the time of route arrangement can be suppressed.

FIG. 8 is an explanatory diagram showing an example of a harness wiring structure on the left side of the engine 4. FIG. 9 is an explanatory diagram of a harness guide that guides the harness. As an example of the harness wiring structure on the left side of the engine 4, as shown in FIGS. 8 and 9, a gutter-shaped holder 47 having a bottom surface 471 and left and right side surfaces 472 and having a substantially U-shaped cross section is shown. Is attached along the axle bracket 63. Then, hoses and harnesses are arranged inside the holder 47.

As shown in FIG. 9, since the holder 47 is divided into two parts in the front and rear of the pipe receiver 18 and the pipe cover 19, it is easy to handle at the time of manufacturing or when attaching to the axle bracket 63. The wiring structure using the holder 47 can be applied not only to the left side of the engine 4 as shown in the figure but also to the hoses and harnesses on the right side.

FIG. 10 is an explanatory diagram showing a state in which the cover is attached to the EGR system 5. The EGR system 5 shown in FIG. 1 becomes extremely hot. Therefore, the EGR system 5 is covered with the EGR cover 500. Specifically, the valve cover 510 covering the EGR valve 51 constituting the EGR system 5 and the cooler cover 520 covering the EGR cooler 52 are integrally attached via the connecting plate 530 to form the EGR cover 500. There is.

By providing the EGR cover 500, it is possible to prevent various hoses and harnesses including the hose 16 from directly touching the EGR valve 51 and the EGR cooler 52 and being damaged by heat. In addition, it is possible to prevent a worker or the like from touching and getting burned.

11 to 14 show hydraulic piping of the orbit roll 20 provided at the lower end of the steering handle 9 and the steering cylinder 62 for steering the left and right front wheels 2 and 2.

Pressure oil from a hydraulic pump (not shown) is supplied to the orbit roll 20 fixed to the vehicle body frame 13 by the mounting bracket 21 at the rear of the engine 4, and the engine 4 is supplied from the orbit roll 20 with the right oil pipe 17R and the left oil pipe 17L. Hydraulic oil is supplied to the steering cylinder 62 of the steering mechanism provided at the lower part.

The left and right oil pipes 17L and 17R are placed on a pipe receiver 18 attached to the side of the left body frame 13, bend from the front end under the pipe cover 19, and further turn right to pass through the guide hole 13H of the left body frame 13L. It is connected to the steering cylinder 62 through the lower side of the belt cover 22 surrounding the transmission belt of the cooling fan.

On the left side surface of the engine 4, a heat source cover 23 that covers the EGR valve 51 and the EGR cooler 52 is provided on the belt cover 22 so as not to conduct heat to the left and right oil pipes 17L and 17R.

Further, a heater hose 24 that circulates hot water from the condenser 41 and the radiator 42 to the air conditioner (not shown) in the cabin 11 passes under the belt cover 22 and the heat source cover 23, and rises upward behind the pipe receiver 18. There is.

2 Front wheel 4 Engine 9 Steering handle 13 Body frame 13H Guide hole 17L Left oil pipe 17R Right oil pipe
18 Pipe receiver 19 Pipe cover 20 Orbit roll 22 Belt cover 23 Heat source cover 24 Heater hose 62 Steering cylinder

Claims (4)

The engine (4) is mounted on the front of the vehicle body frames (13) and (13), and the front wheels (2) and (2) are steered by the steering handle (9) standing at the rear of the engine (4). In the work vehicle, the guide hole (13H) provided in the vehicle body frame (13) from the orbit roll (20) provided at the lower end of the steering handle (9) via the pipe receiver (18) provided on the side portion of the vehicle body frame (13). ), A work vehicle in which the left and right oil pipes (17L) and (17R) are connected to the steering cylinder (62) provided at the bottom of the engine (4). A pipe cover (19) is provided in front of the pipe receiver (18), and the left and right oil pipes (17L) are inserted into the guide holes (13H) of the vehicle body frame (13) from the front end of the pipe receiver (18) under the pipe cover (19). The work vehicle according to claim 1, which is made through (17R). The work vehicle according to claim 1, wherein the left and right oil pipes (17L) and (17R) are connected to the steering cylinder (62) by passing under the belt cover (22) covering the transmission belt to the air-cooled fan of the engine (4). .. A heat source cover (23) that covers the heat source of the engine (4) is provided at the rear of the belt cover (22), and a heater hose (24) that sends hot water from the radiator (42) to the air conditioner is attached to the belt cover (22) and the heat source cover (22). The work vehicle according to claim 1, wherein the work vehicle is started up at the rear portion of the pipe receiver (18) through the side portion of 23).

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