JP2735450B2 - Riding 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 motor for transmitting power to a mower disposed below a vehicle body between a front wheel and a rear wheel via a belt transmission from an engine having an output shaft projecting downward. Related to riding lawn mowers.

[0002]

2. Description of the Related Art Conventionally, the above-mentioned riding lawn mower has been disclosed in
As disclosed in Japanese Patent No. 4920, a mower is suspended from a traveling machine body via a pair of front and rear link mechanisms, and is configured to be able to move up and down by a lift arm for manual operation.

[0003]

Since the mower is suspended from the traveling body via a pair of front and rear links, it is easy to swing back and forth, and a link fulcrum on the traveling body side and an engine are provided. Is different from the distance between the link fulcrum of the mower and the input shaft of the mower, the distance between the output shaft of the engine and the input shaft of the mower changes as the mower moves up and down. Conventionally, swinging of the mower in the front-rear direction due to tension of the belt transmission from the engine to the mower, and loosening of the belt transmission due to a change in the center distance between the output shaft of the engine and the input shaft of the mower. Although it is configured to suppress, since the pair of front and rear links move in the front and rear direction with the adjustment of the mower height by the lift arm, the center distance between the output pulley of the engine and the input pulley of the mower greatly changes. Therefore, there is a disadvantage that the amount of absorption by the tension of the belt transmission increases. SUMMARY OF THE INVENTION It is an object of the present invention to restrict the swing of the mower in the front-rear direction to reduce the change in the amount of tension absorbed by a belt transmission.

[0004]

To achieve the above object, the present invention is characterized in that a restricting link for restricting the position of the mower in the front-rear direction is provided between the traveling body and the mower, and the restricting link is provided. With the pivot point on the traveling body side of the link set near the output pulley of the engine, and with the mower located at an intermediate position in the elevating range, the length is set so that the regulating link has a substantially horizontal posture. It is in the point provided.

[0005]

The swinging motion of the mower is regulated by the regulating link, and the pivot point of the regulating link on the traveling body side is set near the output pulley of the engine. Since the fluctuation of the distance between the shaft and the input shaft on the mower side is reduced, and when the mower is located in the middle of the vertical movement range, the length of the regulating link is set so as to be in a substantially horizontal posture. Even if the mower moves up and down at the lower position, the amount of movement of the mower in the front-rear direction is small, and the change in the amount of absorption of tension during use of the mower can be reduced.

[0006]

As a result of the above structure, the change in the amount of belt tension absorbed due to the vertical movement of the mower can be reduced by a simple structural improvement in which the restricting link is provided, and the uneven rotation of the mower blade can be suppressed. Can be.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows a mid-mounted riding lawn mower,
The riding lawn mower includes a link mechanism at a lower abdomen of a traveling body 5 having a steering handle 1, a driver's seat 2, an engine E, a steering front wheel 3, and a driving rear wheel 4 between front and rear wheels 3, 4. The mower M is mounted to be able to move up and down via R. The mower M is suspended from the body frame 5a by a four-link mechanism R including front and rear operation links 6 and 7 and front and rear links 8 and 9 in a standing posture.
The rear link 7 and the front link 6 to which are attached are linked and connected by a connection link 11.

As shown in FIG. 2, the round bar 1 is attached to the left and right mounting brackets 13, 13 of the cutting blade housing 12 with respect to the rear link 9, and extends over both brackets 13, 13.
4 is provided, and a restriction link 15 for restricting the position of the mower M in the front-rear direction is provided between the left and right substantially central positions of the round bar 14 and the body frame 5a. As shown in FIG. 1, the restriction link 15 is provided on the traveling body 5 of the restriction link 15 so that the distance between the output shaft e of the engine E and the input shaft 16 of the mower M does not change as the mower M moves up and down. The side pivot point a is set near the output shaft e of the engine E, and the length is set so that the regulating link 15 assumes a substantially horizontal posture when the mower M is located in the middle of the elevating range. ing.

The mower M is transmitted from the lower pulley 17a of the engine output shaft e to the mowing blade input shaft 16 of the mower M via a belt transmission device 18. On the other hand, the upper pulley 17b of the engine output shaft e
To continuously variable transmission 19 and belt transmission 20
22 that incorporates forward / reverse switching device 21 via
It is configured to transmit to

As shown in FIG. 3, in the belt continuously variable transmission 19, the pulley 24 on the intermediate shaft 23 side is configured as a split pulley, and the movable pulley piece 24a on the upper side of the split pulley 24 is moved from above. The tension pulley 2 is pressed and urged toward the lower fixed pulley piece 24b side via a spring 24c.
The speed can be increased by forcibly moving the belt 5 in the belt tensioning direction, and the speed can be reduced by relaxing the tension pulley 25.

The forward / reverse switching device 21 is configured to be able to switch between forward and reverse only when the belt continuously variable transmission 19 is at the lowest speed. As shown in FIG. 4, the tension pulley 25 of the belt continuously variable transmission 19, the speed change pedal 26 of the control unit, and the forward / reverse switching lever 27 are formed by a cam plate member 28 that can swing and displace about the axis Z, and The forward operation groove Wf and the reverse operation groove W formed on the cam plate member 28 are formed.
r and a switching groove Wk connecting the two grooves.
A cam mechanism 30 comprising an arm member 29 capable of oscillating and oscillating around a shaft center Y having a pin-shaped engaging portion 29a engaged with the V-shaped operation groove W, and moving forward and backward. When the switching lever 27 is in the forward position, the engaging portion 29a is in the forward operation groove Wf, and the speed change operation from the lowest speed to the highest speed can be performed by depressing the speed change pedal 26.
Is in the reverse position, the engaging portion 29a is located in the reverse operation groove Wr, so that the speed change operation from the lowest speed to the intermediate speed can be performed, and at the same time, the stepless transmission of the belt continuously variable transmission 19 is released at the lowest speed. Only forward / reverse switching lever 27
Are linked so that the switching operation can be performed. In the above-described continuously variable transmission 19, it is attempted to return to the 0th speed only by the belt continuous tension force.
When 6 is released, the tension force of the belt continuously is small,
Since there is a case where super-deceleration appears due to difficulty in increasing the speed, a return spring 31 for the cam plate member 28 is provided to prevent this.

As shown in FIG. 1, an engine cleaner such as an air cleaner 33, a carburetor 34, and a muffler 35 are disposed in a bonnet 32 covering the engine E, and an exhaust pipe 36 of the engine E is provided.
A muffler cover 37 is provided in a state where the carburetor 34 and the exhaust pipe 36 of the engine E are partitioned so that the carburetor 34 is not heated by radiant heat from the engine. After the engine cooling air sucked from the intake port 39 cools the cylinder head 40 of the engine E, it is guided by the muffler cover 37 to cool the muffler 35, and then the opening 41 at the rear of the body frame 5a.
From the outside. As shown in FIG. 5, a muffler cover portion 37a immediately below the carburetor 34 has a double wall structure through which engine cooling exhaust air can pass, and the radiant heat of an exhaust pipe 36 is
It is configured to reduce the heating of the carburetor 34 by the double wall structure. As shown in FIG. 1, an engine inspection opening 42 provided at a lower portion of the cylinder head 40 is closed by a cover 43 so that the engine cooling exhaust air is easily guided to the muffler cover 37.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a partially broken side view showing the entire riding lawn mower.

FIG. 2 is a perspective view showing a mounting structure of a restriction link.

FIG. 3 is a longitudinal sectional view of the belt continuously variable transmission.

FIG. 4 is a schematic diagram showing an interlocking state of an operation system.

FIG. 5 is a perspective view of a driving unit.

[Explanation of symbols]

 Reference Signs List 3 front wheel 4 rear wheel 5 traveling body 8 front link 9 rear link 15 regulating link 18 belt transmission device a pivot point e engine output shaft E engine M mower R quadruple link mechanism

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Minoura 64 Ishizukitamachi, Sakai City, Osaka Prefecture Inside the Kubota Sakai Works (72) Inventor Kazuaki Kurohara 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Corporation Inside the factory (72) Inventor Seiya Harada 64, Ishizukita-cho, Sakai City, Osaka Prefecture Inside the Kubota Sakai Factory (72) Inventor Mikio Yuki 64, Ishizukita-machi, Sakai City, Osaka Prefecture Inside the Kubota Sakai Factory (72) Inventor Hiroyuki Ogasawara 64 Ishizukita-cho, Sakai-shi, Osaka, Japan, inside Kubota Sakai Factory (72) Inventor Shogo Murakawa 64, Ishizukita-machi, Sakai-shi, Osaka, Japan Inside Kubota Sakai Factory, Inc. (72) Inventor Akio Matsui, Osaka, Japan 64 Ishizu-Kitacho, Sakai City Inside Kubota Sakai Works (56) References Open to the public: Sho 63-45138 (JP, U)

Claims (1)

(57) [Claims] 1. A belt disposed on a lower abdomen of a traveling body (5) between a front wheel (3) and a rear wheel (4) in a substantially horizontal direction from an engine (E) having an output shaft protruding downward. A mower (M) to which power is input via a transmission (18) is arranged, and the mower (M) is interposed between a front part and a rear part thereof and the traveling body (5). A riding lawn mower suspended from the traveling body (5) so as to be able to ascend and descend through a four-link mechanism (R) composed of front and rear links (8) and (9) in a posture, A restriction link (15) for restricting the position of the mower (M) in the front-rear direction is provided between the traveling body (5) and the mower (M).
With the pivot point (a) on the traveling body side of the regulation link (15) set near the output shaft (e) of the engine (E),
Further, a riding lawn mower having a length set so that the regulating link (15) has a substantially horizontal posture when the mower (M) is located at an intermediate position in a vertical range.