JP7421696B2 - work vehicle - Google Patents

Description

The present invention relates to a work vehicle such as a tractor.

As described in Patent Document 1, a steering device for a working vehicle drives a hydraulic steering device by rotating a steering handle provided in a driver's seat to steer the front wheels and turn the vehicle. In this hydraulic steering device, rotation of a steering shaft rotated by a steering handle is transmitted to an input shaft of the hydraulic steering device, and the front wheels are steered by hydraulic pressure.

Japanese Patent Application Publication No. 2013-6567

In the above-mentioned steering system for a work vehicle, the steering handle is installed approximately in the center of the left and right sides of the machine, and the hydraulic steering system is installed on the side of the engine mounted in the center of the left and right sides of the machine. The rotational transmission from the shaft to the input shaft of the hydraulic steering device is performed in a bent and connected state from the rear to the front and downward, making it difficult to smoothly transmit rotation of the steering handle to the hydraulic steering device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a steering device for a working vehicle in which a rotational operation of a steering handle is smoothly transmitted to a hydraulic steering device so that a comfortable turning operation can be performed.

The above problems of the present invention are solved by the following technical means.

The first invention is
In a work vehicle that performs a steering operation by transmitting rotation of a steering handle (16) provided in front of a driver's seat (15) to a steering hydraulic control unit (70) provided near an engine (3), the engine (3) A support bracket (50) is installed upright on the cylinder block (31) of 3), and the input shaft ( 71) is provided at the left and right center of the engine (3) and protrudes rearward and upward, and connects the input shaft (71) and the handle shaft (16a) of the steering handle (16),
A work vehicle characterized in that a recess (57e) is formed on the side of the mounting bracket (57) to which the support bracket (50) is attached, through which pipes (45a, 45b) passing across the support bracket (50) are passed. be.
The second invention is
The first working vehicle is characterized in that the steering hydraulic control unit (70) is mounted to the mounting bracket (57) so as to be lifted from the recess (57e).
A first invention related to the present invention is a work vehicle in which rotation of a steering handle 16 provided in front of a driver's seat 15 is transmitted to a steering hydraulic control unit 70 provided near an engine 3 for steering operation. A support bracket 50 is erected on the cylinder block 31 of the engine 3, and an input shaft 71 of the steering hydraulic control unit 70 is attached to the rear side of the engine 3 at the left and right center of the engine 3 via a mounting bracket 57. The working vehicle is characterized in that the input shaft 71 is provided in an upwardly protruding state, and the input shaft 71 and the handle shaft 16a of the steering handle 16 are connected.

A second invention related to the present invention is characterized in that a recess 57e is formed on the mounting side of the mounting bracket 57 to which the support bracket 50 is attached, through which the pipes 45a, 45b that cross the support bracket 50 are passed. A working vehicle of the first invention related to .

A third invention related to the present invention is a work vehicle according to a second invention related to the present invention , characterized in that the steering hydraulic control unit 70 is attached to the mounting bracket 57 while floating from the recessed portion 57e. shall be.

According to the first aspect of the present invention, the handle shaft 16a of the steering handle 16 provided at the left and right center of the aircraft body and the input shaft 71 of the steering hydraulic control unit 70 directed rearward and upward at the left and right center of the engine 3 are straight with few bending angles in the front and rear. As a result, the rotation of the steering handle 16 is transmitted to the steering hydraulic control unit 70, resulting in a smooth turning operation. Further, a mounting bracket 57 to which the steering hydraulic control unit 70 is attached is firmly attached to the support bracket 50 with the pipes 45a and 45b being piped through the recessed portion 57e of the mounting bracket 57 on the side surface of the support bracket 50. The rotation is accurately transmitted to the steering hydraulic control unit 70, ensuring reliable travel operation.
According to the second invention, in addition to the effects of the first invention, the steering hydraulic control unit 70 is attached to the rear side of the mounting bracket 57 with its input shaft 71 protruding rearward and upward. The configuration is simplified.
In a first invention related to the present invention , a handle shaft 16a of a steering handle 16 provided at the left and right center of the aircraft body and an input shaft 71 of a steering hydraulic control unit 70 directed rearward and upward at the left and right center of the engine 3 are bent at the front and rear. Since the steering wheel is connected linearly with few angles, the rotation of the steering handle 16 is transmitted to the steering hydraulic control unit 70, resulting in a smooth turning operation.

A second invention related to the present invention, in addition to the effects of the first invention related to the present invention , provides a steering system in which the pipes 45a and 45b are connected to the side surface of the support bracket 50 through the recess 57e of the mounting bracket 57. The mounting bracket 57 to which the steering hydraulic control unit 70 is attached is firmly attached to the support bracket 50, and the rotation of the steering handle 16 is accurately transmitted to the steering hydraulic control unit 70, thereby ensuring reliable travel operation.

In a third invention related to the present invention, in addition to the effects of the second invention related to the present invention , a steering hydraulic control unit 70 is mounted on the rear side of the mounting bracket 57 so that its input shaft 71 is directed rearward and upward. Since it is attached in a protruding state, the configuration is simplified.

FIG. 1 is a left side view of a tractor according to an embodiment of the present invention. FIG. 1 is a rear perspective view showing the configuration of an engine and its surroundings according to an embodiment of the present invention. FIG. 2 is a rear perspective view of the engine according to the embodiment of the present invention with some devices and parts removed. FIG. 2 is a rear perspective view of the engine according to the embodiment of the present invention with a cover member removed. It is a rear perspective view of the support bracket etc. which are attached to the engine based on embodiment of this invention. FIG. 2 is a front perspective view of the support bracket and the like according to the embodiment of the present invention, viewed from the front side. FIG. 2 is a rear perspective view showing an enlarged view of the upper part of the engine according to the embodiment of the present invention. FIG. 3 is a rear view of the upper part of the engine with the mounting bracket removed according to the embodiment of the present invention. FIG. 2 is a rear view of the upper part of the engine from which the steering hydraulic control unit according to the embodiment of the present invention is removed.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a tractor 1 that is an example of a work vehicle according to an embodiment of the present invention.

The tractor 1 includes a pair of left and right front wheels 11, 11 and a pair of rear wheels 12, 12 arranged on the left and right sides at the front and rear sides of a vehicle body 2.

An engine 3 is mounted at the front of the vehicle body 2 in a space surrounded by a bonnet 13 that can be opened and closed. The bonnet 13 is configured to cover an upper surface portion, a front portion, and the upper portions of the left and right side portions, which are part of the engine 3.

Further, from the center to the rear of the vehicle body 2, a power transmission device 4 is provided that transmits the rotational power of the engine 3 to both the front wheels 11, 11 and the rear wheels 12, 12, or the latter (rear wheels). The power transmission device 4 includes a clutch mechanism (not shown), a main transmission, a sub-transmission, a forward/reverse switching mechanism, a differential, etc., which are arranged inside the transmission case 40.

In addition, the tractor 1 is provided with a lower link 29 for attaching a working machine such as a rotary tiller (not shown) to the rear of the vehicle body 2 (at the rear of the transmission case 40), and a connecting device such as a link mechanism. A PTO shaft 49 for outputting rotational power is provided in the transmission case 40.

Furthermore, the tractor 1 is provided with a cabin 14 that serves as a cockpit, from the center of the vehicle body 2 to the middle of the rear. Inside the cabin 14, a driver's seat 15 where a driver sits and a steering handle (steering wheel) 16 for steering the front wheels 11, 11 are arranged.

A forward/reverse lever 17 is provided on the handle post 21 below the steering wheel 16 and is operated when switching between forward travel and reverse travel. A throttle lever (not shown) is provided on the opposite side of the handle post 21 from the forward/reverse lever 17, which is operated when adjusting the rotation speed of the engine 3. A meter panel 23 is installed in front of the steering wheel 16, which is attached to the upper end of a handle shaft 16a that is erected on the handle post 21, on which information necessary for steering and the like is displayed. Operation levers such as the main gear shift lever 24 are arranged on the left side of the cockpit 15.

A step floor 22 is provided within the cabin 14 below the cockpit 15 and steering wheel 16. The step floor 22 is provided with operating tools such as a brake pedal 18 and a clutch pedal 19.

2 to 4 show the engine 3 and devices or parts installed near it. 3 and 4 are shown with some of the equipment or parts placed near the engine 3 shown in FIG. 2 removed.

For example, a diesel engine is used as the engine 3. As shown in FIG. 4, etc., this engine 3 includes a cylinder head 32, a cylinder cover 33, etc. provided at the top of a cylinder block 31, and an oil pan 34 provided at the bottom of the cylinder block 31. Further, the engine 3 is provided with a cooling fan 35 and the like at the front of the cylinder block 31, and a flywheel case 36 and the like in which a flywheel connected to the crankshaft is disposed at the rear lower part of the cylinder block 31. ing.

The cylinder block 31 is provided with a plurality of cylinders in which a plurality of pistons connected to a crankshaft (not shown) are arranged to reciprocate. The cooling fan 35 is rotated by a fan belt 38 that is rotated by passing around related parts such as a pulley connected to the crankshaft and an alternator 37. (Figure 4)
In this tractor 1, as shown in FIGS. 2, 3, etc., a plate-shaped support bracket 50 is attached to the rear of the engine 3 in an upwardly erected state.

In addition, in this tractor 1, as shown in FIG. A mounting bracket 57 is provided on the rear side of the bracket 50, and a steering hydraulic control unit 70 is mounted on the mounting bracket 57.

First, as shown in FIGS. 5, 6, etc., the support bracket 50 includes a main body 51 that is a substantially rectangular flat plate having a required length and width and long in the vertical direction, and a left and right end of the main body 51. The bracket has a plate-shaped left side plate part 52A and a right side plate part 52B that are bent rearward at an almost right angle.

When the body portion 51 is attached, the surface facing the forward direction of the tractor 1 becomes the front surface 51a, and the surface facing the backward direction of the tractor 1 becomes the rear surface 51b. Both the left side plate part 52A and the right side plate part 52B have a shape in which the upper part thereof protrudes more rearward than the lower part. Further, the support bracket 50 has a concave or U-shaped cross section when viewed from the upper end side.

In addition, the support bracket 50 has a lower part 51c of the main body 51 screwed with fixing screws 9Na into a fixing part 55 having four screw holes on the mounting surface formed on the rear surface of the cylinder head 32 in the upper part of the engine 3. It is stopped and fixed.

At this time, the support bracket 50 is attached with the upper part 51b of the main body 51 protruding upward from the upper part of the engine 3 (for example, the cylinder cover 33), as shown in FIGS. 2, 3, etc.

Next, the mounting fixture 56 for installing the exhaust gas treatment device 60 includes annular holding portions 56a and 56b that are arranged independently on the left and right and hold the exhaust gas treatment device 60, as shown in FIG. 6 and the like. It is comprised of an attachment fixing part 56c that supports the holding parts 56a and 56b and is attached and fixed to the front side of the support bracket 50.

The holding parts 56a and 56b are designed to hold the outer peripheral surface of the exhaust gas treatment device 60, which has a substantially cylindrical appearance, in a tightened state by adjusting the tightening screw. Further, the attachment fixing portion 56c is fixed to the central upper portion 51d side of the front surface 51a of the main body portion 51 of the support bracket 50 with four sets of bolts and nuts 9Nb.

The exhaust gas treatment device 60 is a device that purifies the exhaust gas exhausted from the engine 3, which is a diesel engine. A device is used that has a structure in which the two are connected in series to allow exhaust gas to pass through. DOC performs processing to oxidize harmful components in exhaust gas and render them harmless. The DPF performs a process of collecting particulate matter contained in exhaust gas.

Further, as shown in FIGS. 2, 3, etc., the exhaust gas treatment device 60 is attached to the support bracket 50 via the attachment device 56 so as to be located above the engine 3.

As shown in FIG. 7 etc., the exhaust gas treatment device 60 in this embodiment is configured such that exhaust gas discharged through an exhaust manifold (not shown) of the engine 3 is used for exhaust gas via the exhaust turbine section 42B of the supercharger 42. is taken in from the connecting pipe 43. Furthermore, the exhaust gas treated by the exhaust gas treatment device 60 is discharged from the exhaust pipe 44 and then exhausted from the exhaust muffler 48 (FIG. 1), as shown in FIG. 7 and the like. .

Next, as shown in FIG. 2 or 9, the mounting bracket 57 on which the steering hydraulic control unit 70 is installed is a left mounting side plate portion that is a left and right mounting side plate portion that is arranged facing each other with an interval left and right. The side plate portion 57a and the right mounting side plate portion 57b are connected to the left and right mounting side plate portions 57a and 57b at their upper and lower ends, and the left mounting side plate portion 57a and the right mounting side plate are connected to each other at their upper and lower ends. It is comprised of upper and lower attachment and fixing parts 57c and 57d that attach and fix the upper and lower ends of the part 57b to the rear surface side of the support bracket 50.

The left and right mounting side plates 57a and 57b, which are the left and right mounting side plates, form a concave portion 57e through which the exhaust gas mixing pipe 45a and exhaust gas return pipe 45b that cross the support bracket 50 are passed, and protrude toward the rear side. A part of the steering hydraulic control unit 70 is attached to the inclined part diagonally downward toward the rear with a left mounting side plate part 57a and a right mounting side plate part 57b, which are left and right mounting side plate parts. The structure is such that it can be clipped and attached with fixing screws. Further, the upper and lower mounting fixing parts 57c and 57d are fixed to the lower side of the rear surface 51b of the main body part 51 of the support bracket 50 with four sets of bolts and nuts 9Nd, as shown in FIG. 5 and the like.

As the steering hydraulic control unit 70, a hydraulic steering auxiliary device such as Orbit Roll (registered trademark) is used, for example. The steering hydraulic control unit 70 is fixed between the left and right mounting side plates 57a and 57b, which are the left and right mounting side plates of the mounting bracket 57, and between inclined portions that slope downward toward the rear.

As shown in FIG. 2, the steering hydraulic control unit 70 has a handle shaft 16a of the steering wheel 16 connected to an input shaft 71 that projects rearward and upward through a universal joint, and a plurality of hydraulic pipes. 73 is connected to a hydraulic pump (not shown). The tractor 1 is connected to a hydraulic pump that operates a steering cylinder 75, and is steered by adjusting the direction of the front wheels 11, 11 by a tie rod 76 that is displaced by the operation of the steering cylinder 75.

In addition, in this tractor 1, as shown in FIGS. 2, 3, etc., a rotation support bracket 28 is provided on the upper part of the support bracket 50 to rotatably support the bonnet 13 that covers at least a portion of the engine 3. It is provided.

As shown in FIG. 5, FIG. 6, etc., the rotation support bracket 28 includes plate-shaped left and right support body parts 28a and 28b arranged at a required interval left and right, left and right support body parts 28a, Left and right plate-shaped mounting surfaces 28c and 28d are continuously provided so as to approach the outer surfaces of the left side plate 52A and right side plate 52B of the support bracket 50 from the lower part of the support bracket 50, respectively, and the left and right support body parts 28a, 28b, and bearing portions 28f provided at the upper ends of the left and right support body portions 28a, 28b, respectively.

The bearing portion 28f is configured with a support shaft or a bearing hole depending on the configuration of the rotational attachment portion of the bonnet 13.

The rotation support bracket 28 connects the left and right mounting surfaces 28c and 28d to two sets of upper and lower bolts and nuts 9Nd through screw holes provided at the upper ends of the left side plate 52A and right side plate 52B of the support bracket 50. It can be installed by fixing each with.

The rotation attachment portion of the bonnet 13 is attached to the bearing portions 28f of the left and right support body portions 28a, 28b of the rotation support bracket 28. As a result, the bonnet 13 is rotated so as to lift the front part of the bonnet upward about the bearing part 28f, as illustrated by the two-dot chain line in FIG. 1, and opened. Can be done.

In the tractor 1 described above, the exhaust gas treatment device 60 is installed on the front side of the support bracket 50 attached to the rear of the engine via the mounting fixture 56, and the exhaust gas treatment device 60 is installed on the rear side of the support bracket 50 via the mounting bracket 57. Since the steering hydraulic control unit 70 is installed, there is no need to separately prepare dedicated mounting parts for installing the exhaust gas treatment device 60 and the steering hydraulic control unit 70 near the engine 3. is efficiently arranged near the engine 3.

Therefore, in this tractor 1, a plurality of devices or components can be efficiently arranged on one support bracket 50 attached near the engine 3, and the number of attached parts can be reduced.

Further, in this tractor 1, since the rotation support bracket 28 of the bonnet 13 is provided on the upper part of the support bracket 50, a dedicated bracket configured to be directly attached near the engine 3 is used as the rotation support bracket 28. It is possible to make it smaller compared to . As a result, in the tractor 1, in addition to reducing the number of attached parts, it is also possible to make the attached parts smaller.

Furthermore, the mounting device 56 in this embodiment includes a fixing member 58 that is attached and fixed to the upper part of the engine 3, as shown in FIGS. 3, 5, 6, etc.

As shown in FIGS. 5, 6, etc., the fixing member 58 includes a substantially horizontal support portion 58a that supports the attachment fixing portion 56c of the attachment device 56 from below, and a left support portion 58a that is suspended from the left end of the support portion 58a. It is a member having a shape having a fixing part 58b and a right fixing part 58c hanging from the right end of the support part 58a. The support portion 58a is joined and fixed to an attachment fixing portion 56c of the attachment device 56. The left fixing portion 58b is positioned and fixed to, for example, the left side surface of the cylinder head 32 using a stud 58e or a fixing screw (not shown). The right fixing portion 58c is fixed, for example, to the right side surface portion of the cylinder cover 33 by being screwed with a fixing screw.

As a result, in the tractor 1, the exhaust gas treatment device 60 is installed in a state above the engine 3 on the plate-shaped support bracket 50, which is attached with the upper part protruding above the upper part of the engine 3. Despite this, the mounting device 56 and the fixing member 58 of the exhaust gas treatment device 60 work together to function as a reinforcing member to prevent the support bracket 50 from falling.

As a result, in the tractor 1, the support bracket 50 is kept in a stable state without fear of falling, and the exhaust gas treatment device 60 can be arranged in a stable state.

Further, as shown in FIGS. 2, 3, etc., the support bracket 50 in this embodiment is a part (for example, a rear end portion) of left and right side covers 80A and 80B that cover left and right side portions of the engine 3, respectively. A mounting jig 59 for mounting is provided.

The left and right side covers 80A and 80B are used to discharge heat from the left and right side portions of the engine 3 that are not covered by the bonnet 13, and to prevent hands or the like from accidentally approaching the engine 3 while it is running. It is something.

As shown in FIG. 3, the side covers 80A and 80B are composed of a breathable cover member 81 having a shape corresponding to the area to be covered, and a holding member 82 that holds the cover member 81 in a desired shape. has been done. As the cover member 81, for example, punched metal or the like is applied.

As shown in FIGS. 7, 8, etc., the mounting jig 59 is a support arm portion having a predetermined shape that connects and supports the rear end portions of the side covers 80A, 80B and the side portions of the support bracket 50. a fixing part that fixes one end of the support arm to a part of the holding member 82 inside the rear end of the side covers 80A, 80B by screwing or the like; and a fixing part that fixes the other end of the support arm to the side of the support bracket 50. The left side plate part 52A and the right side plate part 52B have attachment parts attached to the outside of the lower part with bolts and nuts. The support arm portion is composed of a round bar-shaped member.

As a result, in the tractor 1, even around the side surface of the engine 3, parts of the side covers 80A and 80B can be easily positioned via the mounting jig 59 that is attached to the side surface of the support bracket 50. Can be installed.

Further, as shown in FIG. 5, FIG. 6, FIG. A lifting hole 53 is provided for hooking a lifting member used when lifting the engine 3 during periods such as the above.

Examples of the lifting member include hooks, wires, chains, and the like. The lifting hole 53 is set to conditions that match the shape and dimensions of the member to be lifted. As this lifting hole 53, a vertically elongated hole that is long in the vertical direction is formed.

Thereby, in the tractor 1, there is no need to separately provide a dedicated lifting attachment part for hooking a member for lifting the engine 3, and the number of attachment parts can be reduced. Incidentally, in this engine 3, as shown in FIG. 4, a lifting attachment part 85 in which a lifting hole is formed is provided at the front part of the engine 3 so as to protrude upward from the top of the engine 3. ing.

Further, as shown in FIG. 4, etc., the engine 3 in this embodiment reduces the amount of oxygen by returning a part of the exhaust gas to the air supply side and mixing it in, thereby reducing the generation of nitrogen oxides (Nox). An exhaust gas recirculation (EGR) 45 is provided.

As shown in FIG. 4 and the like, the exhaust gas recirculation device 45 is provided to connect an intermediate position of the intake manifold 47 and an EGR cooler 45c that cools the exhaust gas to be returned. In FIG. 4, reference numeral 45b is an exhaust gas return pipe that branches off from the exhaust manifold (not shown), passes through the EGR valve 45v, and connects to the EGR cooler 45c, and reference numeral 45a carries the returned exhaust gas midway through the intake manifold 47. This is a pipe that mixes exhaust gas by pouring it into the location.

A bellows portion 46 is provided between the exhaust gas return pipe 45b and the exhaust gas mixing pipe 45a to absorb stress caused by thermal expansion and vibration. The EGR cooler bellows portion 46 has a bellows-like appearance with a diameter larger than that of the exhaust gas return pipe 45b and the exhaust gas mixing pipe 45a, and is disposed close to the rear surface of the cylinder head 32.

The support bracket 50 in this embodiment is attached to be located between the rear surface of the cylinder head 32 and the exhaust gas recirculation device 45, as shown in FIGS. 5 to 8, and so on. In order to prevent the bellows portion 46 from interfering with the rear surface 51b of the main body portion 51, an interference avoidance opening (escape portion) 54 is provided in a portion of the main body portion 51 that faces the bellows portion 46.

The interference avoidance opening 54 in this embodiment is formed as a horizontally long rectangular hole from the viewpoint of ensuring the strength of the lower part of the support bracket 50. The interference avoidance opening 54 may have any shape as long as it can avoid interference with the bellows portion 46, and may have another opening shape.

Furthermore, as shown in FIG. 4 and the like, the engine 3 in this embodiment is provided with a crankcase purification device (CCV: Closed Crankcase Ventilation) 90 that purifies exhaust gas from the crankcase.

Therefore, as shown in FIGS. 8 and 9, a plate-shaped mounting bracket 91 for installing the crankcase purification device 90 is attached to the lower part of the left side surface portion 52a of the support bracket 50 using bolts and nuts 9Ne. It is fixed and installed. At least a portion of the crankcase purifying device 90 is fixed to a mounting bracket 91 by screws.

In addition, in the above embodiment, a configuration example using DOC and DPF is shown as the exhaust gas treatment device 60, but the exhaust gas treatment device 60 is not limited to this. It may be constructed by applying a selective catalytic reduction (SCR) catalyst that purifies the nitrogen oxides contained.

3 Engine 15 Cockpit 16 Steering handle 16a Handle shaft 31 Cylinder block 45a Exhaust gas mixing pipe 45b Exhaust gas return pipe 50 Support bracket 57 Mounting bracket 57a Left mounting side plate 57b Right mounting side plate 57e Recess 70 Steering hydraulic control unit 71 input shaft

Claims (2)

In a work vehicle that performs a steering operation by transmitting rotation of a steering handle (16) provided in front of a driver's seat (15) to a steering hydraulic control unit (70) provided near an engine (3), the engine (3) A support bracket (50) is installed upright on the cylinder block (31) of 3), and the input shaft ( 71) is provided at the left and right center of the engine (3) and protrudes rearward and upward, and connects the input shaft (71) and the handle shaft (16a) of the steering handle (16),
A work vehicle characterized in that a recess (57e) is formed on the side of the mounting bracket (57) to which the support bracket (50) is attached, through which a pipe (45a, 45b) passing across the support bracket (50) is passed . The work vehicle according to claim 1 , wherein the steering hydraulic control unit (70) is attached to the mounting bracket (57) so as to be lifted from the recess (57e).

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