JP2000351330A - Riding type lawn mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of collision resistance of a rear end part of a vehicle body at the time of turn and front and rear balance in riding type lawn mower of speed differential steering type in which the mower is arranged between a drive rear wheel and a follow-up steering front wheel and a trans mission and an engine are arranged in front of and in the back of the rear wheel, respectively. SOLUTION: HSTs 8 are mounted per a pair of left and right drive wheels 2, 2, a driver's seat is arranged on the front side of an engine 3, and a radiator 25 is arranged between the front and rear of the driver's seat and the engine 3. A guide plate for performing suction of an HST fan 48 from below the engine is provided below the radiator 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a riding lawn mower having a mower at a front portion of a vehicle body, and more particularly to a riding lawn mower provided with a continuously variable transmission mechanism capable of rotating forward and reverse for each of left and right drive wheels. The present invention relates to a riding lawn mower configured to be steered at a difference between left and right driving speeds.

[0002]

2. Description of the Related Art A riding lawn mower of this type has been proposed in Japanese Patent Application No. Hei 10-248987.
It comprises a pair of left and right driven rear wheels, a pair of right and left driven steered front wheels, and a mower disposed between the front and rear of the driven rear wheels and the steered front wheels, and has an HST for each of the left and right rear wheels. The front wheel is driven by the speed difference between the left and right rear wheels, so that the front wheel follows. is there.

[0003]

In the above-mentioned proposed technology, the radiator is disposed further behind the engine disposed behind the rear wheel. Therefore, the radiator is located at the rearmost end of the hood as the vehicle body. It was a part located later. Therefore, when performing a pivot turn that turns around one rear wheel as a fulcrum or a small turn such as the above-mentioned in-situ turn, when the hood that protrudes backward hits an obstacle such as a wall or a grove relatively hard. In, the radiator, which is a weak component in terms of strength, was easily damaged.

[0004] Further, since the engine is generally supported by vibration isolation, the engine and the transmission have a structure in which the engine and the transmission are axially transmitted through a pair of universal joints. The case is arranged at a certain distance from the case. Therefore, the means of positioning the heavy engine in front of the light radiator itself is a preferable means for easily concentrating the mass. It was difficult,
When the size of the engine is increased, such as by replacing it with a diesel engine, the bonnet tends to be further enlarged and the appearance balance tends to deteriorate, leaving room for improvement.

SUMMARY OF THE INVENTION The present invention is directed to a speed differential steerable riding lawnmower having a transmission and a mower in front of a rear wheel and an engine after the rear wheel. It is an object of the present invention to reduce the size of the device and improve the front-back balance.

[0006]

Means for Solving the Problems [Configuration of Claim 1] First
The present invention relates to a riding lawn mower, in which an engine is disposed behind a pair of left and right driving wheels and a mower is disposed on a front side, and a forward / reverse continuously variable reversible continuously mounted is provided for each driving wheel at a front position of the driving wheel. The transmission is configured to transmit the power of the engine to a transmission mechanism, and a driving seat is disposed in front of the engine, and a radiator is disposed between the driving seat and the engine.

According to the first to fifth aspects of the present invention, the radiator is disposed on the front side of the engine, so that the rearmost end in the hood becomes the engine body. Therefore, even if a collision occurs such that the rear end of the bonnet deforms, the surplus of the impact will be received by the relatively strong engine body, and unless the collision is considerable, the bonnet may be damaged. However, functional damage such as crushing of the radiator and the engine cylinder is unlikely to occur.

As described above, since the shaft transmission structure having the universal joint requires a certain longitudinal distance between the engine and the transmission case, it is possible to arrange the radiator at the longitudinal distance. In contrast to the conventional radiator, the bonnet can be made more compact. For example, the bonnet can be arranged at the front and rear positions that are not much different from the conventional one, or can be downsized.

Further, since the radiator is often driven to rotate by a camshaft and is generally arranged at a higher position than the engine, the bonnet shape in a side view is changed so that the height of the bonnet upper surface is on the rear side. It may be in the form of a lower slope or a step which becomes lower as it becomes lower. Therefore, in a side view, the visual connection from the driver's seat arranged at a high position to the hood is improved, and the front-rear balance and the shape balance in appearance are improved.

According to a second aspect of the present invention, in the first aspect, the radiator is located on or substantially on the axis of the driving wheel.

The transmission means from the engine to the transmission case has a construction in which the transmission shaft connected to the crankshaft protrudes forward from the engine. There was a space on the transmission shaft. Therefore, if the radiator arranged at a relatively high position compared to the engine is arranged in the space, that is, on the axis of the drive wheel or almost on the axis, the rearward projection amount of the bonnet by the radiator can be shortened. it can.

Therefore, the possibility of collision with an obstacle at the rear end of the bonnet during a small turn is reduced by the amount that the rear end position of the bonnet is moved forward, and even if the engine becomes large due to the use of diesel or large displacement, etc. There is an advantage that the engine can be increased in size without increasing the amount of rear projection of the hood, for example, the amount of rear projection of the hood can be kept unchanged, as compared with the above-mentioned proposed technology.

According to a third aspect of the present invention, in the first or second aspect, the projected area of the radiator in the front-rear direction is:
It is characterized in that it is larger than the projected area of the engine in the front-rear direction.

According to the third aspect of the present invention, the size of the cross section of the bonnet can be made smaller at the rear part than at the front part of the bonnet, so that the side view can be obtained. In both the plan view and the plan view, the visual connection from the driver's seat to the hood is improved, and the front-back balance and the shape balance in appearance are improved. Further, the heat radiation area of the radiator can be made sufficiently large, and good engine cooling performance can be obtained.

[Structure of Claim 4] The fourth invention is characterized by the first to third aspects.
In the invention, the driver's seat is provided on the continuously variable transmission mechanism and at a position near the front of the radiator.

According to the fourth aspect of the present invention, a substantially L-shaped driver's seat in a side view is provided in front of the radiator and at a position above the useless transmission mechanism. Since the radiator is arranged after the backrest, and the continuously variable transmission mechanism is located close to each other under the seating portion, it is possible to collectively arrange each part without leaving unnecessary space or at least. In addition, the driver's seat can be moved closer to the drive wheels in the front-rear direction, so that the phenomenon that the driver's seat is swung during a small turn such as a turn on the spot is suppressed.

In other words, the driver's seat can be arranged close to the center of rotation while being adapted to the space formed by the radiator and the continuously variable transmission mechanism. A good rational body layout is now available.

[Structure of Claim 5] A fifth aspect of the present invention relates to the first to fourth aspects.
In the invention, the continuously variable transmission mechanism capable of rotating in the forward and reverse directions is constituted by an HST, an HST fan for cooling the HST is provided, and a partition member for sucking the HST fan from below the radiator is provided. There is a feature.

According to the fifth aspect of the present invention, the continuously variable transmission mechanism capable of normal and reverse rotation is HST, so that acceleration and deceleration and normal and reverse rotation can be performed smoothly, and the cooling air is sucked from the lower part of the radiator. By doing so, it is possible to prevent the exhaust heat of the radiator from being taken into the HST. In other words, although the HST fan and the radiator are arranged relatively close to each other, there is an advantage that the HST can be efficiently cooled by eliminating or reducing the influence of the exhaust heat of the radiator.

According to a sixth aspect of the present invention, in a riding lawn mower, an engine is provided behind a pair of left and right drive wheels.
In addition, a mower is arranged on the front side, and the power of the engine is transmitted to a continuously variable transmission mechanism provided for each drive wheel at a position on the front side of the drive wheel, and a driver seat is arranged on the front side of the engine, The fuel tank and the battery are separately arranged on the left and right sides of the driver's seat.

According to the sixth aspect of the present invention, the fuel tank and the battery, which are heavy objects among the components of the vehicle body, are arranged on the left and right sides of the driver's seat. While reducing the deviation of the left-right balance, the drive wheels can be brought closer to the drive wheels in the front-rear direction, so that they can be centrally arranged with other mechanical devices such as a continuously variable transmission mechanism, and the mass can be concentrated. Since the fuel tank and battery are also relatively bulky parts, they are not arranged before and after the driver's seat, so that the driver's seat can be made closer to the driving wheels in the front-rear direction, and the driver's seat can be used when making small turns such as turning on the spot. Is suppressed.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a riding lawn mower in which a mower is mid-mounted on the lower abdomen between the front and rear wheels. Drive rear wheel, 3 is the engine,
4 is a mission case, 5 is a mower, 6 is a driver's seat, 7
Is a lifting link mechanism for suspending the mower 5, and F is a body frame. This lawn mower has an HST for each of the left and right rear wheels 2, 2.
(An example of a continuously variable transmission mechanism capable of rotating forward and reverse) 8 is provided,
The front wheel 1, 1 follows the drive speed difference between the left and right rear wheels 2, 2, and is configured as a speed difference steering system.

As shown in FIGS. 7 and 8, the body frame F
An upper frame 13 supporting the driver's seat 6 is mounted on a main frame f including a rear frame 11 supporting the diesel-type water-cooled engine 3 and the transmission case 4 and a front frame 12 suspending the mower 5. Are connected and integrated. The rear frame 11 includes a pair of left and right plate frame members 9, a rear end horizontal frame 14 connecting them at a rear end, and an intermediate horizontal frame 15 connecting front and rear middle.

The front frame 12 is connected to a square pipe member 10 bent in a front open U shape in a plan view and welded to the front ends of the left and right plate frame members 9 and 9 and the left and right front end portions thereof. The front end horizontal frame 16 is provided. The upper frame 13 straddles a pair of left and right rear vertical frames 18, 18 erected from the plate frame member 9 near the rear axle 17 in the front-rear direction, the front end of the plate frame member 9, and the rear end of the square pipe member 10. A pair of left and right front vertical frames 19 and 19 erected in a state, a pair of left and right upper and front frames 20 and 20 connecting the rear vertical frame 18 and the front vertical frame 19,
Upper horizontal frames 21, 22 before and after connecting these upper horizontal frames 20, 20
It is comprised including.

A downwardly facing U-shaped plate bracket 53 is fixed to the front side of the front end horizontal frame 16. As shown in FIG. 3, a corner provided with the front wheels 1 at the left and right ends of the plate bracket 53 is provided. A front wheel support frame 54 made of a pipe is swingably supported on a rolling fulcrum P which coincides with the left and right center C of the vehicle body in the left and right direction. The rolling limit of the front wheels 1 and 1 is, for example, the front wheel support frame 54 and the plate bracket upper surface 5.
It is determined by contact with 3a, and can be rolled freely within a predetermined range. The front wheel 1 has a bearing bracket 5
A caster wheel is supported by the front wheel support frame 54 so as to be rotatable about a vertical rotation axis X via the center wheel 5.

The engine 3 is supported on four brackets 23 at the front, rear, right and left by projecting inwardly from the left and right plate frame members 9 by rubber mounts or the like. The suction cooling fan is mounted on the front side of the engine 3. 24, before that radiator 2
5 are arranged. The radiator 25 includes a pair of left and right brackets 26 projecting inward from the left and right plate frame members 9,
As shown in FIG. 6, a transmission shaft 27 for interlocking the engine 3 and the transmission case 4 is provided immediately below the transmission shaft 27 with a pair of universal joints (not shown). The radiator 25 is mounted at a position almost directly above the rear axle 17 in a side view, although slightly skewed rearward. Immediately before the radiator 25, a dustproof net 30 for preventing foreign matter from being sucked is disposed.

The radiator 25 is located at a position higher than the engine 3 and has a projected area in the front-rear direction.
Is larger than the projected area in the front-rear direction, the hood 29 has a shape that is narrowed in both the plan view and the side view despite the muffler 28 being disposed on the engine 3. Is set. In this case, the projected area of the engine 3 is a single engine that does not include auxiliary equipment such as the muffler 28 and a fuel injection device (not shown).

As shown in FIGS. 3 to 5, the transmission case 4 has a bifurcated shape in which a rear axle case 32 is bolted to both left and right sides of a center case 31 to which engine power is input. The center case 31 has casing portions 31 of HST8 and HST8 on the left and right sides of the input case portion 31a.
b, 31b are integrated with each other to distribute the power input to the input shaft 33 to the left and right HSTs 8, 8.
PTO shaft 34 protruding forward for mower 5 drive
And The rear axle case 32 transmits the output of the HST 8 to the rear wheel 2 via a gear reduction mechanism (not shown), and the left and right rear axle cases 32, 32 are located below the left and right plate frame members 9, 9. The transmission case 4 is mounted and supported on the rear frame 11 by being bolted at a location straddling the recessed location.

As shown in FIGS. 1 and 2, the driver's seat 6
The fuel tank 35 is provided on the upper frame 13 below the rear wheel fender 50 on the left side thereof, and the battery 36 is provided below the rear wheel fender 50 on the right side thereof. A pair of left and right speed change levers 37, 37, which are operated by the left and right hands, are provided on the right and left sides of the unit, and are oscillated back and forth. A space is provided between the back surface of the backrest 6a of the driver seat 6 and the front surface of the hood 29 so that cooling air for the radiator can be taken in from the front end of the hood 29 sufficiently and sufficiently.

On the right side of the driver's seat 6, a PTO clutch on / off lever (not shown) for interrupting power to the mower 5 is provided.
And a hand accelerator lever (not shown). An elevating lever 40 for elevating and lowering the mower 5 manually is provided on the right side of the front of the driver seat 6, and a parking brake lever 41 is provided on the left side. A clutch lever (not shown) for traveling is arranged behind the driver's seat 6.

As shown in FIG. 6, the lifting link mechanism 7 is
A pair of front and rear arms 44, 45 provided between the front frame 12 and the cutting blade housing 43 are provided on the left and right, and a rotating shaft 46 for interlockingly connecting the left and right rear arms 45, 45;
Gear interlocking mechanism 4 extending over operation shaft 40a of elevating lever 40
7 is provided. That is, when the lifting lever 40 is pivoted upward, the mower 5 is lifted, and when the lifting lever 40 is pivoted downward, the mower 5 is lowered.

As shown in FIG. 5, H for cooling HST 8
An ST fan 48 is provided, and a guide plate (an example of a partition member) 49 for sucking air into the HST fan 48 from below the radiator 25 is provided. That is, an HST fan 48 for the left and right HSTs 8 and 8 is provided on the input shaft 33 of the center case 31, and a guide plate 49 descending from below the radiator 25 is attached so as to suck air from the space below the engine 3.

That is, the cooling air of the HST 8 is sucked from below the engine 3 into a front exhaust structure, and the cooling air from the radiator 25 is sucked from behind the driver's seat 6 and exhausted from the rear surface of the hood 29 to a rear exhaust structure. The provision of the guide plate 49 prevents interference of exhaust heat with each other.

[Another Embodiment] As the continuously variable transmission mechanism 8 capable of rotating in the normal and reverse directions, a friction type continuously variable transmission mechanism using a disc (C
VT). Further, a combination structure in which the belt continuously variable transmission and the forward / reverse switching mechanism are linked so as to be operated in an interlocked manner so that the speed can be changed by a single operation of a single lever or the like is also possible.

A rear lawn mower having a structure in which a rear frame 11 is extended rearward, a caster wheel 1 is disposed at a rear end thereof, and a mower 5 having a front driving wheel and a rear steering wheel is front-mounted. Is also good.

[Brief description of the drawings]

FIG. 1 is a side view of a riding lawn mower.

FIG. 2 is a plan view of a riding lawn mower.

FIG. 3 is a plan view showing a configuration of a lower part of the vehicle body;

FIG. 4 is a front view showing the vicinity of a mission case and a driver seat.

FIG. 5 is a side view of a partially cutaway view showing a structure of a rear portion of the vehicle body.

FIG. 6 is an enlarged side view of a main part showing the elevating structure of the mower.

FIG. 7 is a side view showing the structure of the vehicle body frame.

FIG. 8 is a plan view showing the structure of the vehicle body frame.

[Explanation of symbols]

 Reference Signs List 2 drive wheel 3 engine 5 mower 6 driver's seat 8 continuously variable reversible transmission mechanism 25 radiator 35 fuel tank 36 battery 48 HST fan 49 partition member

Continuing on the front page (72) Inventor Hironori Dobashi 64 Ishizukita-cho, Sakai City, Osaka, Japan Inside Kubota Sakai Works, Ltd. (Reference) 2B083 AA02 BA12 BA18 CA28 DA02 DA08 EA19 GA06 HA13 HA16 HA19 3D038 AA10 AB05 AC04 AC10

Claims (6)

[Claims] An engine is provided behind a pair of left and right drive wheels.
And a mower disposed on the front side to transmit power of the engine to a forward / reverse continuously variable transmission mechanism provided for each drive wheel at a position on the front side of the drive wheel; And a radiator is disposed between the driver seat and the engine before and after the driver seat. 2. The radiator is mounted on an axis of the drive wheel.
2. A riding lawn mower according to claim 1, wherein the riding lawn mower is located substantially on the axis. 3. The projection area of the radiator in the front-rear direction is:
The riding lawn mower according to claim 1 or 2, wherein the area is larger than a projected area of the engine in the front-rear direction. 4. The passenger according to claim 1, wherein the driver's seat is disposed on the continuously variable transmission mechanism capable of rotating forward and reverse and at a position near the front of the radiator. Type mower. 5. The continuously variable transmission mechanism capable of rotating forward and reverse is HST
5. An HST fan for cooling the HST is provided, and a partition member for sucking air into the HST fan from below the radiator is provided. Riding lawn mower according to the paragraph. 6. An engine is provided behind the pair of left and right drive wheels.
And a mower disposed on the front side to transmit power of the engine to a forward / reverse continuously variable transmission mechanism provided for each drive wheel at a position on the front side of the drive wheel; A ride-on lawn mower in which a driver's seat is arranged and a fuel tank and a battery are separately arranged on the left and right sides of the driver's seat.