JPH06135245A - Drive device for work vehicle - Google Patents

Abstract

PURPOSE:To increase stability at the time of high speed travel and improve drastically cooling efficiency without equipping a special cooling means specially and by this, realize high speed travel on a general public road. CONSTITUTION:The frame of a lower part travel body 10 is formed by a section U type frame, and a drive unit 30 whose main body is an engine 40, is mounted by locating it between a turning axis portion 36 and a travel front wheel axle 38 at the U type frame inside. The cooling efficiency of a cooling device including a radiator 52 in a travel state is improved by especially arranging the radiator 52 at the travel front portion of the lower part travel body 10 and fitting a cooling fan 54 so as to be able to suck and send air.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a work vehicle, and more particularly to a drive device for a work vehicle in which a cooling device is preferably arranged so as to improve cooling efficiency.

[0002]

2. Description of the Related Art In a conventional work vehicle such as a power shovel, an upper revolving structure is attached to a lower traveling structure, and a boom or arm mounted on the upper revolving structure operates a working machine such as a bucket at the tip to perform a predetermined work. I am trying to make it. In such a work vehicle, an engine is generally mounted on an upper revolving structure, a hydraulic pump is driven by this engine to obtain hydraulic pressure for operating a working machine, and the output shaft of the traveling hydraulic pump is used as a revolving shaft portion. And extends to the lower traveling body, and this is transmitted to the wheel axle via a speed reducer or the like to obtain traveling force.

Further, a work vehicle of this type is provided with an overhang frame in which a rear frame of a lower traveling body, particularly a rear frame, is extended from a rear wheel, such as a rough terrain crane, and a drive unit such as an engine is mounted on the overhang frame. It is known that an overhang frame is provided on a side portion of a lower frame and a drive unit such as an engine is mounted on the side frame of a lower frame like a work vehicle equipped with a telescopic fork.

By the way, in the structure in which the drive unit is incorporated in the upper revolving structure, the cooling device of the driving device is generally arranged on the side or rear of the revolving structure.
Further, even when an engine is mounted on the rear overhang portion of a lower traveling body such as a rough terrain crane, a cooling device is mounted on the side overhang portion to cope with the problem. This is because the fan that constitutes the cooling device is driven by the engine and the cooling fluid flows out of the engine, and the configuration attached to the engine cannot be avoided. In addition, the fan is usually configured to ventilate the exhaust air, and the cooling air is blown out of the machine.

[0005]

[Problems to be Solved by the Invention] However, work vehicles running on general roads are required to have higher speeds in the future, and it is necessary to increase the cooling capacity of engine cooling water accordingly. . On the other hand, with the conventional cooling device arrangement, the structure focuses on the cooling capacity during work, so when the vehicle speed is increased, the horsepower increases only when the vehicle is running. A separate means for improving efficiency is required. For example, in the conventional wheel type power shovel, about 80 horsepower is required for work and 110 horsepower at the time of running, so it is not necessary to give much importance to cooling efficiency.
When traveling on an ordinary road at a speed of 50 km / h or more, the required horsepower for traveling must exceed 140 horsepower.
Therefore, in the conventional work vehicle, there is a problem that the high speed vehicle is limited in terms of cooling efficiency.

Focusing on the above-mentioned conventional problems, the present invention has a structure in which a work vehicle having an upper revolving structure mounted on a lower traveling structure has extremely high stability during high-speed traveling, and a special cooling means is separately provided. It is an object of the present invention to provide a drive device for a work vehicle that can significantly improve cooling efficiency without installing any equipment and thus can drive a public road at high speed.

[0007]

In order to achieve the above object, a drive device for a work vehicle according to the present invention comprises an upper revolving structure including a work machine, an arm and a boom for driving the work machine, and an upper revolving structure. In a working vehicle including a lower traveling body that supports a revolving structure via a revolving shaft portion and travels, a frame of the lower traveling body is formed by a U-shaped cross-section frame, and the revolving shaft portion in the U-shaped frame. And a drive unit mainly composed of an engine, which is located between the front wheel axle and the front wheel axle of the vehicle, a radiator is arranged on the front surface of the traveling portion of the lower traveling body, and a cooling fan is attached so that suction air can be blown. .

[0008]

According to the above construction, in a work vehicle having an upper revolving structure, the drive unit including the engine can be arranged in a midship on the lower traveling structure while the vehicle length and the vehicle width can be shortened to achieve a low center of gravity. Therefore, it is possible to improve traveling stability and drive the work vehicle at high speed. When the work vehicle is traveling, since the cooling device is arranged in the front part of the lower traveling body in the traveling posture, traveling wind can be introduced,
Moreover, since the suction fan blows the air, it is possible to efficiently cool the engine without providing a separate cooling means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of a drive device for a work vehicle according to the present invention will be described in detail below with reference to the drawings.

1 to 3 are schematic configuration diagrams of a work vehicle equipped with a drive device according to an embodiment. This work vehicle includes a lower traveling body 10 and an upper revolving superstructure 12 attached to an upper portion of the lower traveling body 10.
A work device 14 and a driver's cab 16 which are mounted so as to be elevated are provided in the. The working device 14 is a revolving structure 1.
2, a boom 18 supported by the armature 2, an arm 20 attached to the tip of the boom 18, and a bucket 22 provided at the tip of the arm 20. Particularly in this work vehicle, the boom 18 is connected to the first boom 18a and the second boom 1
It is configured by pin connection with 8b so that the folded and stored state is substantially within the range of the revolving structure 12 and does not project from the front and rear ends of the frame of the lower traveling structure 10. Then, both booms are formed in a bell crank shape, and the bent portion of the first boom 18a is attached to the revolving structure 12 so that it can be lifted up and down by the support pin 23 at a position slightly forward of the revolving center, and one end of the first boom 18a is hydraulically moved. It is pivotally attached to the rear end of the second boom 18b via a cylinder 24. This hydraulic cylinder 24 is moved to the second position by contraction operation.
The boom 18b is operated so as to stand upright with respect to the first boom 18a. Further, a hydraulic cylinder 26 that connects the bent portion of the second boom 18b and the revolving structure 12 is provided, and by extending this hydraulic cylinder 26, the first boom 18a is operated in the upright direction. Therefore, the working device 14 is configured to have a low height even in the retracted state, and the center of gravity of the working vehicle is set to be low.

In such a construction, in the embodiment, the drive unit 30 is mounted on the lower traveling body 10 supporting the revolving superstructure 12. That is,
As shown in FIG. 3, the undercarriage 10 is a revolving structure 1
A frame 34 having a U-shaped cross section is provided on the lower surface side of the second mounting surface 32, and the drive unit 30 is mounted inside the U-shaped frame 34. In this case, the drive unit 30 is arranged in the longitudinal direction of the vehicle between the turning shaft portion 36 penetrating the turning body mounting surface 32 and the drive axle 38 of the front wheels, and particularly on the front side. The engine 40 and the transmission 42 are arranged, and the turning shaft 36
The hydraulic pump 43 is disposed on the left side portion and the hydraulic motor 44 is disposed on the right side portion so as not to interfere with the vehicle (see FIG. 2). Also, the engine 4
Since 0 can be arranged so as to overlap the front wheel drive axle 38, the drive axle 38 is an independent suspension system that does not require an axle, and the revolving structure mounting surface 32 protruding from the side portion of the U-shaped frame 34 is provided. A suspension 46 supporting the drive axle 38 is provided between the side edge flanges.
The differential gearbox 48 is installed on the axle.
Also, a constant velocity joint 50 is provided to distribute the power to the left and right. Further, since the differential gear box 48 interferes with the engine 40 when it is arranged at the center of the axle, in the embodiment, the differential gear box 48 is laterally offset and the engine 40 is offset in the opposite direction.
Both are prevented from interfering with each other, and the engine 40 can be arranged to be overlapped on the axle.

A radiator 52 is further installed at the front end of the frame on the lower traveling body 10 on which the drive unit 30 is mounted, and the radiator 52 and the engine 4 are also installed.
It has a structure in which a cooling fan 54 is arranged between 0 and 0. The cooling fan 54 is driven by the engine 40, and is configured to suck and blow air to the radiator 52. As a matter of course, the radiator 52 allows the engine cooling water to flow therethrough, and the cooling water is cooled by the heat exchange by the forced introduction of the running wind to cool the engine 40.
Recycle to.

In the drive system for a working vehicle of the above embodiment, the drive unit 30 including the engine 40 is mounted inside the lower traveling body 10, so that the lower traveling body 1 having a flat upper surface is used.
It can be set to 0, and not only the effect of improving the visibility is large, but it can be used as the lower traveling body 10 common to various work vehicles. In addition, a comparatively heavy object such as the engine 40 and the transmission 42 is the undercarriage 1.
It is arranged near the center of 0 and has a structure with excellent running stability, and can run on public roads at 50 k / m or more, and the running power is not taken in from the upper revolving structure 12 side but the lower traveling structure 10 It can be directly taken in from the drive unit 30 inside and the efficiency during traveling can be improved to 90% or more from what was conventionally about 70%.

As a result, it is possible to cool the cooling water by introducing traveling air into the cooling device composed of the radiator 52 and the cooling fan 54 arranged at the front end portion of the lower traveling body 10 to cool the cooling water. Can be increased. Therefore, it is possible to increase the speed of the work vehicle and increase the cooling capacity by taking in the traveling wind, and in particular, it is possible to provide the cooling capacity commensurate with the increase in the running horsepower accompanying the high speed running.

[0015]

As described above, according to the drive system for a working vehicle according to the present invention, the frame of the lower traveling body is formed by a U-shaped cross-section frame, and the turning shaft portion in the U-shaped frame. The drive unit mainly composed of the engine is mounted between the front wheel axle and the front wheel axle, and the radiator is placed on the front traveling portion of the undercarriage and the cooling fan is attached so that suction air can be blown. It is possible to significantly improve the cooling efficiency without providing any special cooling means separately while allowing the structure to have extremely high stability during traveling, and thus to enable high-speed traveling on general public roads.

[Brief description of drawings]

FIG. 1 is a side configuration diagram of a work vehicle equipped with a drive device according to an embodiment.

FIG. 2 is a plan configuration diagram of a lower traveling body.

FIG. 3 is a side view of the same configuration.

FIG. 4 is a plan view and a side view of a main part of a drive unit.

FIG. 5 is an explanatory diagram of a power train of a drive unit.

[Explanation of symbols]

 10 Lower Traveling Body 12 Upper Revolving Body 14 Working Device 16 Driver's Cab 18 Boom 20 Arm 22 Bucket 23 Support Pins 24, 26 Hydraulic Cylinder 30 Drive Unit 32 Revolving Body Mounting Surface 34 U-Shaped Frame 36 Slewing Shaft 38 Drive Axle 40 Engine 42 Transmission 43 Hydraulic Pump 44 Hydraulic Motor 46 Suspension 48 Differential Gear Box 50 Constant Velocity Joint 52 Radiator 54 Cooling Fan

Claims (1)

[Claims] 1. A work vehicle comprising an upper revolving structure including a working machine, an arm and a boom for driving the working mechanism, and a lower traveling structure that supports the upper revolving structure via a revolving shaft portion and travels. A frame of the lower traveling body is formed by a U-shaped cross-section frame, and a drive unit mainly composed of an engine is mounted between the turning shaft portion and the front wheel axle of the traveling in the U-shaped frame, and A drive device for a work vehicle, characterized in that a radiator is disposed on a traveling front surface of a lower traveling body, and a cooling fan is attached so as to be capable of sucking and blowing air.