JPH09272349A - Riding lawn mower - Google Patents

Abstract

(57) [PROBLEMS] To provide a riding lawn mower that prevents damage to a continuously variable transmission due to vibration transmitted from an engine via a transmission shaft and reasonably transmits power even to a mower. An intermediate case (4) for transmitting power transmitted from an engine (3) to a continuously variable transmission (6) and a mower (M) in a branched manner.
2 is arranged at an intermediate position between the continuously variable transmission 6 and the mower M in a side view, and the engine 3 is provided at an upper position of the intermediate case 42.
An input shaft for inputting power transmitted from the intermediate case 42 is provided, and an output pulley 47 for transmitting the power from the intermediate case 42 to the continuously variable transmission 6 is provided at an upper position of the intermediate case 42,
An output shaft for transmitting power from the intermediate case 42 to the mower M is provided at a lower position of the intermediate case 42.

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 an engine at a front portion of a traveling body having front and rear wheels, a continuously variable transmission at a rear portion, and a mower at an intermediate position between the front and rear wheels so as to be movable up and down. More specifically, the present invention relates to an improvement in technology for transmitting power to a continuously variable transmission and a mower.

[0002]

2. Description of the Related Art Conventionally, there is a riding lawn mower configured as described above, as disclosed in Japanese Patent Laid-Open No. 7-156672. In this conventional example, the attitude in which the input shaft of a continuously variable transmission is projected forward is known. And a pulley that rotates integrally with the input shaft, and the belt is wound around the mid PTO at the lower position and the pulley provided on the coaxial core.
By providing a PTO clutch between the lower pulley and the mid PTO, the power from the engine can be transmitted to the continuously variable transmission, and at the same time, can be transmitted to the mower via the belt transmission system and the PTO clutch. .

[0003]

In the structure of the conventional example, the input shaft of the continuously variable transmission is arranged at a relatively upper position, and the mid PTO with respect to the mower is arranged at a relatively lower position. Therefore, it is possible to secure a wide ascending space of the mower without being hindered by the transmission shaft for the continuously variable transmission, and at the same time, to drive the mower by the driving force from the mid PTO having a height close to that of the mower. There is.

[0004] However, in the structure of transmitting power from the engine directly to the input shaft of the continuously variable transmission as in the conventional example, the portion supporting the input shaft is easily damaged by the vibration of the engine. In particular, in a device including a belt transmission system for transmitting power from the input shaft to the mid PTO as described in the conventional example, the input shaft vibrates while the belt tension is constantly applied to the input shaft. Therefore, the input shaft portion is more likely to be damaged, and there is room for improvement.

An object of the present invention is to rationalize a riding lawn mower in which damage to the input shaft portion of a continuously variable transmission is unlikely to occur and power from an engine is branched and transmitted to the continuously variable transmission and mower. The point is to configure.

[0006]

A first feature of the present invention (Claim 1) is, as described at the beginning, that an engine is provided at a front portion of a traveling machine body having front and rear wheels and a continuously variable transmission is provided at a rear portion thereof. In a riding lawnmower equipped with a mower that can be raised and lowered at an intermediate position between the front and rear wheels, a side view of an intermediate case for branching and transmitting the power transmitted from the engine to the continuously variable transmission and the mower. It is arranged at an intermediate position between the continuously variable transmission and the mower, and is provided with an input shaft, to which power transmitted from the engine is transmitted, at an upper position of the intermediate case in such a manner that the input shaft projects forward. An output pulley for transmitting power from the intermediate case to the continuously variable transmission is provided at an upper position of the case, and an output shaft for transmitting power from the intermediate case to the mower is projected forward at a lower position of the intermediate case. Located that it includes at energized, the action is as follows.

A second feature of the present invention (claim 2) is that the intermediate case is constructed with a built-in clutch mechanism capable of switching between a state in which power is transmitted to the output shaft and a state in which power is not transmitted to the output shaft. And its action is as follows.

[Operation] According to the first feature, the power from the engine is transmitted to the input shaft at the upper position of the intermediate case, and the continuously variable transmission is transmitted from the output pulley at the upper position of the intermediate case via the belt. Since the vibration from the engine is not directly transmitted to the continuously variable transmission, the structure of the belt transmission system makes it difficult to transmit the vibration, so that the intermediate case may vibrate even if the intermediate case vibrates. It becomes difficult to transmit vibration to. Further, power can be transmitted to the mower from a low level near the mower with a short transmission distance. Further, since the intermediate case is arranged at an intermediate position between the continuously variable transmission and the mower, and the input shaft of the intermediate case is arranged at an upper position, the intermediate case itself or the engine to the intermediate case is moved when the mower is moved up and down. It is possible to avoid a phenomenon in which the mower comes into contact with a transmission shaft system that transmits power and to ensure a wide space for raising and lowering the mower above the mower.

According to the second feature, the mower can be driven and stopped by operating the clutch mechanism, and the clutch mechanism can be protected by the intermediate case.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, an engine 3 is arranged at the front of a traveling body including a front wheel 1 that can be steered and a rear wheel 2 that is driven, and a steering handle is provided at the center of the body. 4 with the driver's seat 5 at the rear
And a hydrostatic stepless transmission 6 for transmitting power to the rear wheels 2 below the rear position of the machine body. Further, the mower M is moved up and down to an intermediate position between the front wheels 1 and the rear wheels 2. A riding lawn mower is freely prepared.

The engine 3 is of a diesel type and is supported by a pair of left and right body frames 7 constituting a traveling body via an elastic material (not shown) such as rubber. A radiator fan 8, a radiator 9, and a battery 10 are disposed on the vehicle, and a muffler 11 is disposed on a front position of the engine 3;
It has. Further, a steering gear mechanism 14 that is linked to the front wheels 1 (the linkage is not described in detail) is provided at the lower end portion of the handle shaft 13 that is connected to the steering handle 4, and further, the stepless step is provided at the right front portion of step 15. A shift pedal 16 and a brake pedal 17 for shifting the transmission 6 are provided.

The step 15 and the rear fender 18 are formed as an integral body, and the front end of the integral body is connected to the body frame 7 so as to be swingable around a lateral support shaft 19, and The rear end portion is elastically supported by the body frame 7 via a pair of left and right suspension springs 20, and the driver seat 5 is supported at an intermediate position between the left and right rear fenders 18. As described above, since the system for supporting the driver's seat 5 with respect to the body frame 7 is elastically supported via the suspension spring 20, a good ride quality is exhibited.

A resin fuel tank 21 and a reserve tank 22 are arranged below the driver's seat 5, and an elevating lever 23 for raising and lowering the mower M is arranged on the right side of the driver's seat 5. There is.

As shown in FIG. 3, the mower M has three blades 26 mounted in the cutting blade housing 25 so as to be rotatable around its longitudinal axis, and the blade 26 at the center position.
The rotary shaft 26A is provided with an input shaft 27 which is interlocked with an upper portion of the rotary shaft 26A via a gear (not shown) and projects rearward. A drive pulley 28 is provided at an upper position of the rotary shaft 26A. 28 and the rotation axis 26 of the other two blades 26
The endless belt 29 is wound around the drive pulley 28 provided in A, and the three blades 26 can be simultaneously driven by the power transmitted to the input shaft 27.

Further, the cutting blade housing 25 of the mower M is provided with a roller 30 at the front part and a gauge wheel 31 at the rear part, and the mower M is supported by the machine body frame 7 via a link mechanism L so as to be vertically movable. ing. This link mechanism L
A pair of left and right main links 34 interposed between a support plate 32 on the front part of the machine body frame 7 and a bracket 33 on the rear part of the cutting blade housing, and swingable around a lateral axis 35 in the middle part of the main links 34. One end of the cutting blade is supported by the machine frame 7 and the other end is composed of a balance piece 38 supported on the upper surface of the cutting blade housing via a link piece 36 and a bracket 37. Lifting link 3 that connects with bracket 33 at the rear of the housing
9 is mechanically linked to the elevating lever 23, so that the elevating lever 23 can be manually moved up and down.

As shown in FIG. 1, the continuously variable transmission 6 is integrally formed at a rear position of a transmission case 41 containing a differential device (not shown) for the rear wheels 2, and the continuously variable transmission 6 is provided. The transmission power is transmitted to the transmission case 41 directly. Also, the power from the engine 3 is transmitted to the continuously variable transmission 6 at an intermediate position between the transmission case 41 and the mower M in a side view and substantially below a connecting portion between the step 15 and the rear fender 18.
And an intermediate case 42 for branching and transmitting to the mower M.

As shown in FIG. 4, this intermediate case 42 is
Is supported by the body frame 7 via a horizontal support plate 43 that is connected and fixed to the left and right members of the body frame 7, and is provided with an input shaft 44 that projects forward at an upper position. Is provided with an intermediate shaft 46 in a vertical posture in which power from the input shaft 44 is transmitted via a bevel gear mechanism 45. An output pulley 47 for transmitting power to the continuously variable transmission 6 is provided at an upper end of the intermediate shaft 46, and an airframe. A power take-off pulley 48 for transmitting power to external devices is provided integrally with the pulley. Further, the input shaft 4 is provided inside the intermediate case 42.
The large-diameter gear 50 that meshes with the small-diameter gear 49 provided in 4 is arranged below the small-diameter gear 49, and the output shaft transmitted via the electromagnetic clutch 51 to transmit the power from the large-diameter gear 50 to the mower M. 52 is provided so as to project forward. The electromagnetic clutch 51 is installed in the intermediate case 42, and is electrically operated so that the power from the intermediate case 42 is transmitted to the mower M by the entering operation and the power to the mower M is shut off by the disengaging operation to stop the mower M. It is constructed so that it can be turned on and off.

An output shaft 3A (see FIG. 1) is formed in the engine 3 so as to project rearward, and the output shaft 3A is formed.
A transmission shaft 55 is interposed between the input shaft 44 of the intermediate case 42 and the intermediate case 42 via a universal joint 54.
Further, the continuously variable transmission 6 has an input pulley 56 and a cooling fan 58 formed on a vertically oriented input shaft 56, and the endless belt 5 extends between the input pulley 57 and the output pulley 47.
9 is wound. A drive shaft 61 is interposed between the input shaft 27 of the mower M and the output shaft 52 via a universal joint 60.

With this configuration, the power from the engine 3 is transmitted to the input shaft 44 above the intermediate case 42 via the power transmission shaft 55 at the time of work, so that the power transmission shaft 55 can be obtained.
Is placed at a higher position, and the mower M is placed above the mower M.
It is possible to secure a wide space for raising and lowering the
By forming a system for transmitting power from the lower part of the intermediate case 42 to the mower M, power can be transmitted from an appropriate height close to the mower M. Further, since the intermediate case 42 is supported by the machine body frame 7 and the system for transmitting power from the intermediate case 42 to the continuously variable transmission 6 is constituted by a belt, the vibration from the engine 3 is transmitted to the continuously variable transmission 6. The damage of the continuously variable transmission 6 can be reduced by avoiding the phenomenon of direct transmission. Further, when the machine body is provided with an external device such as a grass collecting device or a ground working device, the external device The external device can be driven by winding the belt around the input pulley (not shown) and the power take-off pulley 48 of the intermediate case 42.

[Other Embodiments] In the present invention, instead of the electromagnetic clutch built in the intermediate case, a wet multi-plate type clutch which is turned on and off by hydraulic pressure, or a manually operated bite type clutch is used. It is possible to implement by providing a chain type transmission system composed of a chain and a sprocket instead of the transmission system composed of the small diameter gear and the large diameter gear built in the intermediate case.

[0021]

Accordingly, a riding lawn mower that is less likely to cause damage to the input shaft portion of the continuously variable transmission and can reasonably branch the power from the engine to the continuously variable transmission and the mower is rational. (Claim 1). Further, the clutch mechanism having high durability can be used to perform work by arbitrarily controlling the mower (claim 2).

[Brief description of drawings]

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

FIG. 2 is an overall plan view of the riding lawn mower.

FIG. 3 is a plan view showing a transmission system.

FIG. 4 is a side view of the longitudinal side surface of the intermediate case and the transmission system.

[Explanation of symbols]

 1, 2 front and rear wheels 3 engine 6 continuously variable transmission 42 intermediate case 44 input shaft 47 output pulley 51 clutch mechanism 52 output shaft

Claims (2)

[Claims] 1. A riding lawn mower having an engine at a front portion of a traveling machine body having front and rear wheels, a continuously variable transmission at a rear portion, and a mower vertically movable at an intermediate position between the front and rear wheels. An intermediate case, which branches and transmits the power transmitted from the engine to the continuously variable transmission and the mower, is arranged at an intermediate position between the continuously variable transmission and the mower in a side view, and an upper portion of the intermediate case. An input shaft to which power transmitted from the engine is input is provided in a position so as to project forward, and an output pulley for transmitting power from the intermediate case to the continuously variable transmission is provided at an upper position of the intermediate case. A riding lawn mower provided with an output shaft for transmitting power from the intermediate case to the mower at a lower position of the intermediate case in a posture of protruding forward. 2. The riding lawn mower according to claim 1, wherein the intermediate case has a built-in clutch mechanism capable of switching between a state in which power is transmitted to the output shaft and a state in which power is not transmitted to the output shaft.