JP3359669B2 - Work vehicle drive - Google Patents

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 suitably 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 swing body is attached to a lower traveling body, and a work machine such as a bucket at the tip is operated by a boom or an arm mounted on the upper swing body to perform a predetermined work. I try to make it. In such a working vehicle, generally, an engine is mounted on an upper revolving structure, and a hydraulic pump is driven by the engine to obtain hydraulic pressure for operating a working machine, and an output shaft of the traveling hydraulic pump is connected to a revolving shaft. And is extended to a lower traveling body, which is transmitted to a wheel axle via a reduction gear or the like to obtain a traveling force.

[0003] Further, this type of working vehicle is provided with an overhang frame, such as a rough terrain crane or the like, in which a rear frame of a lower traveling body, particularly a rear frame is extended from a rear wheel, and a drive unit such as an engine is mounted on the overhang frame, or 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 a side of a lower frame, such as an aerial work vehicle equipped with a telescopic fork.

By the way, in a structure in which a drive unit is incorporated in the upper revolving unit, the cooling device of the driving device is generally arranged on a side or a rear portion of the revolving unit.
Further, when an engine is mounted on the rear overhang portion of the lower traveling body such as a rough terrain crane, a cooling device is mounted on the side overhang portion. This is because the fan that constitutes the cooling device is driven by the engine and the cooling fluid flows out of the engine, so that the cooling device must be attached to the engine. Normally, the fan is configured so as to ventilate the exhaust air, and the cooling air is blown out of the machine.

[0005]

However, work vehicles traveling on general roads are increasingly required to operate at higher speeds, and accordingly, it is necessary to increase the cooling capacity of engine cooling water. . On the other hand, in the arrangement of the conventional cooling device, since the structure pays attention to the cooling capacity at the time of work, when the speed of the vehicle is increased, the horsepower only at the time of traveling increases, so the cooling at the time of traveling is performed. A means for improving the efficiency is required separately. For example, a conventional wheeled excavator requires about 80 hp at the time of work and at most about 110 hp at the time of traveling, so it was not necessary to pay much attention to cooling efficiency.
When traveling on a general road at 50 km / h or more, the required horsepower at the time of traveling must exceed 140 horsepower.
Therefore, there is a problem that the conventional working vehicle is restricted from being a high-speed vehicle in terms of cooling efficiency.

The present invention focuses on the above-mentioned conventional problems, and in a working vehicle having an upper revolving structure mounted on a lower traveling structure, a special cooling means is separately provided while having a structure having extremely high stability at high speed traveling. It is an object of the present invention to provide a drive device for a work vehicle that can significantly improve cooling efficiency without providing facilities and thereby enable high-speed traveling on general public roads.

[0007]

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

[0008]

According to the above construction, in a work vehicle equipped with an upper revolving structure, a drive unit including an engine can be arranged in the lower traveling structure with a midship, and both the vehicle length and the vehicle width can be shortened and the center of gravity can be reduced. Thus, the working vehicle can be driven at high speed with improved running stability. When traveling the work vehicle, since the cooling device is arranged in front of the lower traveling body in the traveling posture, traveling wind can be introduced,
In addition, since the suction ventilation is performed by the suction fan, the engine can be efficiently cooled without providing a separate cooling unit.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a working vehicle driving apparatus according to an embodiment of the present invention.

FIGS. 1 to 3 are schematic structural views of a working vehicle equipped with a drive device according to an embodiment. The work vehicle includes a lower traveling body 10 and an upper revolving body 12 attached to an upper portion of the lower traveling body 10.
Is provided with a working device 14 and a driver's cab 16 which are mounted so as to be able to descend. The working device 14 is a revolving superstructure 1
2, an arm 20 attached to the tip of the boom 18, and a bucket 22 provided at the tip of the arm 20. In particular, in this work vehicle, the boom 18 is connected to the first boom 18a and the second boom 1
8b, so that the folded and retracted state is substantially within the range of the revolving unit 12, and is set so as not to protrude from the front and rear ends of the frame of the lower traveling unit 10. Then, both the booms are formed in a bell crank shape, and the bent portion of the first boom 18a is attached to the revolving body 12 at a position slightly forward of the center of rotation by the support pin 23 so as to be able to be lowered, and one end of the first boom 18a is hydraulically connected. It is pivotally connected via a cylinder 24 to the rear end of the second boom 18b. The hydraulic cylinder 24 is moved to the second
The boom 18b is operated so as to stand up with respect to the first boom 18a. Further, a hydraulic cylinder 26 is provided for connecting the bent portion of the second boom 18b and the revolving unit 12, and the first boom 18a is operated in the upright direction by extending the hydraulic cylinder 26. Therefore, the working device 14 is configured to have a low height even in the stowed state, and is set so that the center of gravity of the working vehicle is low.

In such a configuration, in the embodiment, a drive unit 30 is mounted on the lower traveling body 10 supporting the revolving body 12. That is,
The undercarriage 10 is, as shown in FIG.
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 disposed between the turning shaft portion 36 penetrating through the turning body mounting surface 32 and the drive wheel axle 38 of the front wheel in the longitudinal direction of the vehicle, and particularly, on the front side. The engine 40 and the transmission 42 are arranged, and the transmission 42
The hydraulic pump 43 is disposed on the left side and the hydraulic motor 44 is protruded on the right side toward the rear of the vehicle so as not to interfere (see FIG. 2). Engine 4
The drive axle 38 is an independent suspension system that does not require an axle so that the revolving body mounting surface 32 projects from the side of the U-shaped frame 34 in order to be able to be disposed overlapping with the front wheel drive axle 38. A suspension 46 is provided to support the drive axle 38 between the side flanges.
A differential gear box 48 is provided on the axle.
And a constant velocity joint 50 to distribute power to the left and right. Further, if the differential gear box 48 is arranged at the center of the axle, it interferes with the engine 40. Therefore, in the embodiment, the differential gear box 48 is offset right and left, and the engine 40 is offset in the opposite direction.
The two are prevented from interfering with each other, and the engine 40 can be arranged to overlap on the axle.

A radiator 52 is further provided 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
0, and a cooling fan 54 is arranged between them. The cooling fan 54 is driven by the engine 40 and the like , and is configured to suction and blow air to the radiator 52. The radiator 52 naturally allows the engine cooling water to flow, and cools the cooling water by heat exchange by forcibly introducing the traveling wind, thereby causing the engine 4 to cool.
Recirculate to zero.

In the driving device for a working vehicle according to the above-described embodiment, the driving unit 30 including the engine 40 is mounted inside the lower traveling body 10, so that the lower traveling body 1 has a flat upper surface.
0, which not only has a large effect of improving the visibility, but also can be used as the lower traveling body 10 common to various types of work vehicles. Also, the relatively heavy ones such as the engine 40 and the transmission 42
0 is disposed near the center of the travel becomes a highly stable structure, the public roads as well as being able to travel at 50k m / h or more, the undercarriage of the running power instead of taking from the upper rotating body 12 side The driving efficiency is directly taken in from the driving unit 30 in the vehicle 10, and the efficiency at the time of traveling can be improved from about 70% in the past to 90% or more.

As a result, the running air can be introduced into the cooling device including the radiator 52 and the cooling fan 54 arranged at the front end of the lower running body 10 to cool the cooling water, and the cooling capacity of the cooling water can be reduced. Can increase. Therefore, as the speed of the work vehicle increases, the cooling capacity can be increased by taking in the traveling wind. In particular, the cooling capacity corresponding to the increase in the running horsepower accompanying the high speed traveling can be provided.

[0015]

As described above, according to the drive apparatus for a work vehicle according to the present invention, the frame of the lower traveling body is formed by a U-shaped frame in section, and the turning shaft portion in the U-shaped frame is provided. A drive unit mainly consisting of an engine is mounted between the axle and the front axle, and a radiator is arranged on the front of the lower traveling body and a cooling fan is attached to the lower traveling body so that it can suction and blow air. While having a structure with extremely high stability during running, the cooling efficiency can be greatly improved without special equipment for special cooling means, thereby enabling high speed running on general public roads.

[Brief description of the drawings]

FIG. 1 is a side view of a working vehicle equipped with a drive device according to an embodiment.

FIG. 2 is a plan view showing a configuration of a lower traveling body.

FIG. 3 is a side view of the configuration.

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lower traveling body 12 Upper revolving superstructure 14 Working device 16 Operator's cab 18 Boom 20 Arm 22 Bucket 23 Support pin 24, 26 Hydraulic cylinder 30 Drive unit 32 Revolving superstructure mounting surface 34 U-shaped frame 36 Revolving shaft part 38 Driving 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60K 11/00-11/08 B60K 5/00-5/04 B62D 21/18

Claims (1)

(57) [Claims] 1. A work vehicle comprising a work machine, an upper revolving body provided with an arm and a boom for driving and operating the same, and a lower traveling body which travels while supporting the upper revolving body via a revolving shaft portion. The frame of the lower traveling body is formed by a U-shaped frame in section, and a drive unit mainly including an engine is mounted between the turning shaft portion and the traveling front wheel axle in the U-shaped frame, A driving device for a working vehicle, wherein a radiator is arranged on a front portion of a traveling portion of a lower traveling body, and a cooling fan is attached so as to be able to suction and blow air.