JPH1045049A - Crawler belt vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To offset the gravity center of a crawler belt vehicle backward for applying proper load to a front wheel by arranging an engine between the front end and the rear end of a crawler belt. SOLUTION: An engine 11 with a transmission 11a is wholly arranged between the front end and the rear end of a crawler belt 9. The engine 11 is preferably arranged between the center of a rear wheel 6 and an intermediate wheel 7 and, in addition, the ratio of the first distance L1 from the center C of a crankshaft for the engine 11 to the center of the rear wheel 6 to the second distance L2 from the center C of the crankshaft to the center of the middle wheel 7 is most preferable to be about 2:1. The first distance L1 is preferably 30% of a center-to-center distance L3 (a wheel base as the third distance) between the front wheel 5 and the rear wheel 6. Part of the engine 11 is arranged in the loop of the crawler belt 9 in a side view.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a crawler belt type vehicle having a front wheel as a tire and a rear wheel as a crawler.
Half-crawler vehicle).

[0002]

2. Description of the Related Art Conventionally, as a half-crawler vehicle, for example, Japanese Unexamined Patent Publication No. Sho 60-143189, "Vehicle for Rough Terrain"
Technology. The above technology is disclosed in FIG. 2 and FIG.
According to the figure, a front wheel 12 with a balloon tire, a rear wheel 13 with a balloon tire, and an idle wheel 24 are mounted in this order on a body frame 11 (the numbers are cited in the gazette; the same applies hereinafter). In this configuration, a rubber track 27 is stretched over the wheel 13 and the idle wheel 24. The engine 21 is connected to the front wheels 12
And the rear wheel 13.

[0003]

Generally, a half-crawler vehicle that runs on soft ground such as snowy or muddy roads requires a large crawler driving force, so that the engine becomes large and heavy. In half crawler vehicles,
Thus, the mounting position of the heavy engine has a large effect on the wheel load (the weight of the vehicle acting on the wheels).
The running performance on snow is determined by the contact pressure of the front wheel and the contact pressure of the crawler. In particular, when the contact pressure of the front wheel is small, the sinking depth of the front wheel becomes too small. If the sinking depth is too small, the projected area from the side of the part sinking in snow or mud is small,
Steering resistance is also reduced. For this reason, the steering resistance becomes too small, and it becomes difficult to secure sufficient maneuverability on a soft ground.
Also, when the contact pressure of the front wheels is large, the sink depth of the front wheels becomes excessive. If the sinking depth is too large, the resistance to snow and mud will increase, and it will be difficult to improve the turning performance, and it will be particularly noticeable in fresh snow and unexplored ground. For this reason, the influence of the wheel load is a significant factor in determining the contact pressure. Further, in order to travel on a soft ground, it is necessary to reduce the weight of the vehicle.

It is an object of the present invention to improve the running performance of a crawler belt type vehicle on a soft land such as snow or a muddy road.

[0005]

According to a first aspect of the present invention, there is provided an engine driven crawler belt type vehicle having a front wheel as a pneumatic tire and a rear wheel as a crawler. Is disposed between the front end and the rear end.

[0006] By arranging the engine between the front end and the rear end of the crawler belt, the center of gravity of the crawler belt type vehicle can be deviated rearward, so that the wheel weight of the front wheels can be made appropriate. As a result, the traveling performance of the crawler belt type vehicle on soft ground can be improved. Further, since the engine for driving the crawler is disposed between the front end and the rear end of the crawler belt, the driving mechanism between the engine and the crawler can be shortened, and thus the driving mechanism can be reduced in weight.
As a result, the overall weight of the crawler belt type vehicle is reduced, and the running performance on soft ground is improved.

According to a second aspect of the present invention, all or a part of the engine is disposed in a loop of the crawler belt in a side view.

In a side view, in the loop of the crawler belt,
Since all or a part of the engine is arranged, the center of gravity is lowered, and running stability is increased. In addition, since the height of the vehicle around the crawler can be reduced, when a carrier is provided at the rear of the vehicle body, it is easy to load and unload the cargo on the carrier.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a side view of a crawler belt type vehicle according to the present invention. The crawler belt type vehicle 1 is a so-called half crawler vehicle in which front wheels are tires and rear wheels are crawlers.

More specifically, a crawler belt type vehicle 1 includes a front wheel 5 as a drive wheel and a rear wheel 6 as a drive wheel provided on a body frame (vehicle) 4 having a front cabin 2 and a rear carrier 3. And an intermediate wheel 7 as an idle wheel interposed between the front and rear wheels 5 and 6 and an equalizer 8 interposed between the rear and intermediate wheels 6 and 7 are mounted on the left and right sides. This is a four-wheel drive / crawler type vehicle in which a crawler is configured by extending a crawler belt 9 (between wheels) between the vehicle and a middle wheel 7.

The front wheel 5, the rear wheel 6 and the intermediate wheel 7 are provided with rubber pneumatic tires, which are balloon tires. The front wheel 5 has a larger diameter than the rear wheel 6 and the intermediate wheel 7.
The crawler belt 9 is made of a flexible material such as a rubber material, and has a plurality of side guide portions 9a (...) on the inner peripheral surface and on both sides in the width direction with respect to the shoulder portion of the tire.
same as below. ) Is raised, and a predetermined uneven pattern (lag pattern) is formed on the ground plane 9b. The vehicle body frame 4 has an engine 11 with a transmission 11a attached to a rear portion by brackets 4a, 4a.

The crawler belt type vehicle 1 has a contact surface pressure of the tire of the front wheel 5 of 0.1 to 0.15 kg / cm.
² , while the contact pressure of the crawler belt 9 is set in the range of 0.04 to 0.05 kg / cm ² .

When the crawler belt type vehicle 1 is running on a soft ground such as snow, the contact surface pressure of the tire of the front wheel 5 is set to 0.1.
If it is smaller than 1 kg / cm ² , the sink depth of the front wheel tire becomes too small. If the sinking depth is too small, the projected area from the side of the part sinking in snow, mud, or the like is small, and the steering resistance is also small. For this reason, the steering resistance becomes too small, and it becomes difficult to secure sufficient maneuverability on a soft ground. Also,
If the contact pressure of the tire of the front wheel 5 is larger than 0.15 kg / cm ² , the sink depth of the front wheel tire becomes excessive. If the sinking depth is too large, the resistance to snow and mud will increase, and it will be difficult to improve the turning performance, and it will be particularly noticeable in fresh snow and unexplored ground.

On the other hand, when the contact pressure of the crawler belt 9 is set to 0.1.
If it is smaller than 0.4 kg / cm ² , the sink depth of the crawler belt 9 will be too small, and the contact pressure will be 0.05 kg / cm ^2.
If it is larger than cm ² , the sinking depth of the crawler belt 9 will be excessive. If the sinking depth of the crawler belt 9 is too small or too large, the running resistance on the running road surface becomes large, so that it is difficult to improve the running performance, and it is particularly remarkable on fresh snow and unexplored ground.

Therefore, it is preferable that the contact surface pressure of the tire of the front wheel 5 and the contact surface pressure of the crawler belt 9 be set in the above ranges. In order to set the contact pressure in such a range, the engine 11 with the transmission 11a
The whole is disposed between the front end and the rear end of the crawler belt 9. The engine 11 includes a center of the rear wheel 6 and an intermediate wheel 7.
And a first distance L ₁ from the center C of the crankshaft of the engine 11 to the center of the rear wheel 6, and from the center C of the crankshaft to the center wheel 7. the ratio of the second distance L ₂ to the center, about 2: it is most preferred to be set to 1. In addition, the first
Distance L ₁ is preferably in a proportion of about 30% of L ₃ (wheelbase as a third distance) center-to-center distance between the rear wheel 6 and the front wheels 5. Further, a part of the engine 11 with the transmission 11a is disposed in the loop of the crawler belt 9 in a side view (in this figure). The reason for setting the engine 11 in this manner will be described later.

The carrier 3 is integrally mounted on the upper rear part of the body frame 4. 14 is a muffler, 15 is a passenger seat, 16 is a steering handle, 17 is a change lever, 18 is an accelerator pedal, 19 is a brake pedal, 21 is a side brake, and 22 is a front fender.

FIG. 2 is a plan view of the crawler belt type vehicle according to the present invention, showing a state where the cabin 2 and the carrier 3 are removed. The carrier 3 is shown by imaginary lines in FIG. The vehicle body frame 4 includes a front suspension 25, a steering device 30, and a front wheel drive device 40 at a front portion, and a rear suspension device 50 and a rear wheel drive device 60 at a rear portion.

The steering device 30 includes a tie rod 31 for transmitting a steering force of the steering handle 16 indicated by an imaginary line, and tie rod ends 3 at both ends of the tie rod 31.
Knuckle arms 33, 33 connected to the knuckle arms 33, 33 and the support shafts 5a, 5 of the front wheels 5, 5.
and a king pin 34, 34, etc., which are connected to

The front wheel drive unit 40 includes a propulsion shaft 41 extending from the front of the transmission 11a,
, The differential 42 and the front wheel 5,
Left and right drive shafts 43, 4 connected to the 5 support shafts 5a, 5a.
Consists of three. Reference numeral 44 denotes a gear box interposed in the middle of the propulsion shaft 41. The gear box 44 has a built-in transmission mechanism for shifting the front wheels 5 and a clutch mechanism for turning on / off power transmission to the front wheels 5.

In the rear suspension device 50, a pair of left and right swing arms 51, 51 are attached to the rear part of the body frame 4 so as to be vertically swingable. Swing tube (connecting member) between
The sub-beams 53, 53 are attached to both ends of the swinging tube 52 so as to be able to swing up and down, and these sub-beams 53, 53 extend forward in the running direction, and intermediate wheel support shafts 54, 54 are provided at their front ends. Are rotatably mounted, and the intermediate wheels 7, 7 are attached to the distal ends of the intermediate wheel support shafts 54, 54, respectively.
Further, it is suspended by oil dampers 55. The oil dampers 55 will be described in detail with reference to FIG. Reference numeral 59 denotes a swingable cross rod, which is a combination of the left sub beam 53 and the right sub beam 53.

The rear wheel drive device 60 includes a propulsion shaft 61 extending from a rear portion of the transmission 11a.
And a left and right drive shaft 64, 64 connected to the differential device 63, and rear wheels 6, 6 connected to both ends of the drive shaft 64. is there. The differential device 63 and the drive shafts 64, 64 are arranged concentrically with the rocking tube 52, and are connected to the rocking tube 52 so as to be rockable, thereby forming a part of the rear suspension device 50. . The swing tube 52 is configured to rotatably support the drive shafts 64, 64 inserted therein.

FIG. 3 is a side view of the rear suspension device according to the present invention. The rear suspension device 50 includes a front end portion and a rear end portion of a sub beam 53 on oil carriers (shock absorbers) 55, 55 on a rear carrier 3. The part is suspended. By the way, the sub-beam 53 is configured so that the tension of the crawler belt 9 (see FIG. 1) can be adjusted. Specifically, the sub beam 53 is attached to the front side surface of the beam member 56 suspended by the oil dampers 55, 55 so that the beam extension portion 57 can be slid forward and backward, and furthermore, the beam member 56 and the beam extension portion 57 are turnbuckled. The slide buckle 58 adjusts the tension of the crawler belt 9 with a slide-adjustable connection. The beam extension 57
Has an intermediate wheel support shaft 54 at the front.

Next, the results of experiments on the running performance of the crawler belt type vehicle 1 will be described. FIG. 4 is a graph showing the running performance of a crawler belt type vehicle. The horizontal axis represents the vehicle weight ratio W (%) acting on the front wheels with respect to the total vehicle weight, and the vertical axis represents the running performance of the vehicle. The running performance is determined by the driver's operation feeling. The conditions of the crawler belt type vehicle 1 are as follows. (1) Total vehicle weight (total weight) of crawler belt type vehicle 1 = about 500 kg (2) Weight of engine 11 with transmission 11a = about 50 kg (3) Tire diameter of front wheel 5 = 33 inches (838 mm) (4) Front wheel 5 Tire width of 12 inches (305 mm) (5) Tire diameter of rear wheel 6 and intermediate wheel 7 = 500 mm (6) Center distance between front wheel 5 and rear wheel 6 = 2050 mm (7) Rear wheel 6 and intermediate wheel 7 And the center-to-center distance = 900 mm. (8) The width of the crawler belt 9 = 400 mm. The running condition of the crawler belt type vehicle 1 is a flat fresh snow area.

According to the experimental results, the vehicle weight ratio W was 30
When it was set to ４０40%, it was found that the running performance was the highest in a fresh snow area. Note that the vehicle weight ratio W is 30 to 40.
When it was set to%, it was found that the running performance was sufficiently high even when driving in a snowy or muddy place. In order to set the vehicle weight ratio W to 30 to 40%, it is preferable to set the dimensional ratio and the like of the crawler belt type vehicle 1 as follows. (A) first distance L ₁ / third distance L ₃ = 0.3 (B) first distance L ₁ : second distance L ₂ = 2: 1 (C) middle wheel 7 and rear wheel 6 Load distribution = 4: 6

In the above embodiment, the crawler belt 9 is not limited to a flexible crawler belt made of a flexible material, but may be a rigid crawler belt.
Further, the engine 11 may be all or partly disposed in the loop of the crawler belt in a side view.

[0026]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect of the present invention, since the engine is disposed between the front end and the rear end of the crawler belt, the center of gravity of the crawler belt type vehicle is biased backward, so that the wheel weight of the front wheels can be made appropriate. . As a result, the traveling performance of the crawler belt type vehicle on soft ground can be improved. Further, since the engine for driving the crawler is disposed between the front end and the rear end of the crawler belt, the driving mechanism between the engine and the crawler can be shortened, and thus the driving mechanism can be reduced in weight. As a result, the overall weight of the crawler belt type vehicle is reduced, and the running performance on soft ground is improved. .

According to a second aspect of the present invention, the whole or a part of the engine is disposed in the loop of the crawler belt in a side view, so that the center of gravity is lowered and the running stability is increased. In addition, since the height of the vehicle around the crawler can be reduced, when a carrier is provided at the rear of the vehicle body, it is easy to load and unload the cargo on the carrier.

[Brief description of the drawings]

FIG. 1 is a side view of a crawler belt type vehicle according to the present invention.

FIG. 2 is a plan view of a crawler belt type vehicle according to the present invention.

FIG. 3 is a side view of the rear suspension device according to the present invention.

FIG. 4 is a graph showing the traveling performance of a crawler belt type vehicle.

[Explanation of symbols]

1: Crawler belt type vehicle, 5: front wheel, 6: rear wheel, 7 ...
Middle wheel, 9 crawler belt, 11 engine, 11a
…transmission.

Claims (2)

[Claims] 1. An engine driven crawler belt type vehicle having a front wheel as a pneumatic tire and a rear wheel as a crawler, wherein the engine is disposed between a front end and a rear end of the crawler belt. Crawler belt type vehicle. 2. The crawler belt type vehicle according to claim 1, wherein all or a part of the engine is disposed in a loop of the crawler belt in a side view.