JP2585498B2 - Mid-mount lawn mower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact mid-mount lawn mower equipped with an engine at a rear portion.
The present invention relates to a muffler arrangement structure that contributes to downsizing of an engine mounting portion.

[0002]

2. Description of the Related Art Japanese Patent Application No. 3-33 filed earlier by the present application.
In No. 3099, a small mid-mount type with the same ease of handling as a walk-behind lawnmower in order to reduce the operator's labor in mowing work in a relatively small area suitable for a walk-behind lawn mower Lawn mowers have been proposed.

[0003]

In the above-mentioned proposed technology, it is disclosed that a muffler is simply arranged in an engine hood. However, in this case, the radiant heat of the muffler heats up the inside of the engine bonnet or reduces the heat. There is a concern that the hood will be enlarged to avoid this. The object of the present invention is to improve the arrangement structure of the muffler,
An object of the present invention is to provide a compact driving unit suitable for a small lawn mower by preventing a remarkable rise in temperature in an engine bonnet and suppressing an increase in the size of the bonnet.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to an airframe in which a control section is mounted at the front and a longitudinal axis engine is mounted at the rear. A transmission gear is disposed at a rear position of the rear axle located below the engine, and a mower arrangement space is provided in front of the rear axle and below the body frame. The muffler for the engine is arranged by dropping it down to the state below the fuselage frame through the notch formed in the fuselage frame at the position below the engine, and further, a wind guide cover for guiding the engine cooling air to the outer periphery of the muffler is provided. A mid-mount lawn mower is constituted.

[0005]

[Function] In order to construct a compact mid-mount lawn mower with a small overall length, it is desirable to arrange the rear wheel, mower and front wheel as close to each other as possible. Is advantageous in terms of downsizing and small turning by shortening the distance between the front and rear axes.
The body frame by the sheet metal member can be easily configured in a flat shape with a short vertical width, which can contribute to lowering the body height and lowering the center of gravity, and the upper and lower spaces are clearly separated by the body frame, This also makes it easier to secure the space for arranging the mower. And, since the muffler of the engine mounted on the fuselage frame is dropped down from the notch of the fuselage frame and arranged, and a wind guide cover is provided so that the engine cooling air reaches the outer periphery of the muffler, Despite the muffler being located below, the radiant heat can be dissipated and the inside of the engine bonnet is prevented from becoming hot, and the rear axle and mower at the lower position of the engine are located because the transmission is located behind the rear axle. The empty space between the space for installation and the space for space can be effectively used as the space for muffler arrangement. In addition, with this muffler arrangement structure, the muffler arrangement space in the engine hood can be omitted, which contributes to downsizing of the hood.

[0006]

As a result, the mid-mount lawn mower, whose compactness has been promoted by effective use of the space by dropping the muffler and downsizing of the engine bonnet, has been improved despite the downsizing of the engine hood. Temperature rise is suppressed, and it is possible to realize such a state that adverse effects due to heat are unlikely to occur, such as overheating is likely to occur or fuel filling efficiency is reduced.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows a cross-sectional view of a mid-mount lawn mower.
FIG. 2 is an overall side view, wherein 1 is a front steering wheel, 2 is a driving rear wheel, A is a driving unit, B is a steering unit, C is a transmission unit, 3 is a mower, and 4 is a body frame. The prime mover A includes a longitudinal axis type engine 5, an engine hood 6, a muffler 7, an air cleaner 8, a carburetor 9, and the like, and is mounted on the body frame 4. As shown in FIG. 1, the body frame 4 has a cross-sectional shape formed by left and right channel portions 4a, 4a and a plane portion 4b that integrates them, and has a lateral width extending to the left and right of the body. It is composed of a sheet metal member. The control section B includes a front panel 11 having a handle 10, a step floor 12, and a driver's seat 1.
The driving seat 13 is located immediately in front of the engine 5, and the battery 15 and the fuel tank 1 are provided inside a floor cover 14 that covers a lower portion of the driving seat 13.
6 is deployed. The transmission portion C protrudes downward from an HST (hydrostatic continuously variable transmission, corresponding to a transmission) 18 disposed on the rear side of the rear axle 17, an input shaft 19 of the HST 18, and the body frame 4. It comprises a first belt interlocking mechanism 21 extending over the crankshaft 20, a second belt interlocking mechanism 23 extending over the crankshaft 20 and the mowing shaft 22 of the mower 3, etc., and the rear axle 17, the differential mechanism 24, and the like. Is H
It is integrally provided in a casing 18a that houses ST18. The casing 18a is suspended from and supported by a sub-frame 25 fixed to the rear lower surface of the body frame 4, and is substantially closed by left and right side walls 25a, 25a of the sub-frame 25, a rear wall 25b, and the casing 18a. A first belt interlocking mechanism 21 is provided in the space.

Next, the arrangement structure of the muffler 7 will be described. As shown in FIGS. 1 to 3, the forced air-cooled engine 5 is mounted in a horizontal upright position with a cylinder head 5a facing left, and a cylindrical muffler 7 is disposed immediately below the cylinder head 5a in a front-rear direction. It is set up. This position is a space that does not interfere with the casing 18a, the first belt interlocking mechanism 21, and the space S for arranging the mower.
The muffler 7 is dropped into the body frame 4 in a state where most of the muffler 7 is located inside the sub-frame 25 by passing through the notch 26 formed in the flat portion 4b. The muffler 7 is covered with a wind guide cover 27 having a shape composed of the front and rear walls 27a, 27a and the right curved side wall 27b. As a result, the cooling exhaust air that has cooled the cylinder head 5a is exhausted. Of the sub-frame 25, and is discharged out of the machine from an air outlet 28 formed in the left side wall 25a of the sub-frame 25. Further, an exhaust pipe 7A of the muffler 7 is formed so as to protrude laterally through the exhaust port 28 so that the exhaust gas discharged from the exhaust outlet 7a flows in the lateral direction of the machine body along with the cooling exhaust air.

[Another embodiment] As shown in FIG.
A extends rearward from the rear surface of the muffler 7, and an exhaust outlet 7 a is provided to exhaust rearward from the opening of the rear wall 25 b of the subframe 25, and includes left and right walls 27 b, 27 b and a front wall 27 a. A configuration in which the air guide cover 27 is provided to guide the cooling exhaust air to the rear may be used.

[0010] In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a partially cutaway rear view of a rear part of an aircraft.

FIG. 2 is a side view of a mid-mount lawn mower.

FIG. 3 is a partial plan view of a rear part of the lawn mower showing a structure of a muffler part.

FIG. 4 is a side view of the lawn mower showing another structure of the muffler mounting portion.

[Explanation of symbols]

 4 Airframe 5 Engine 7 Muffler 17 Rear axle 18 Transmission 26 Notch 27 Wind guide cover B Control section

Claims (1)

(57) [Claims] 1. An airframe (4) on which a control section (B) is provided at the front and a longitudinal axis engine (5) is mounted and deployed at the rear is formed by a sheet metal member having a lateral width extending to the right and left of the airframe. A rear axle (1) located below the engine (5).
7) A traveling transmission (18) is arranged at the rear side position, and a mower arrangement space (S) is provided in front of the rear axle (17) and below the body frame (4). A state in which a muffler (7) for the engine (5) is provided below the engine frame (4) at a position below the engine (5) through a notch (26) formed in the airframe frame (4). A mid-mount lawn mower provided with a wind guide cover (27) for guiding engine cooling air to the outer periphery of the muffler (7).