JPH05328816A - Lawn mower - Google Patents

Abstract

PURPOSE:To obtain a rational ground pressure reducing mechanism of reel mower capable of readily dealing with a different measure. CONSTITUTION:A lawn mower 1 is liftably connected through rise and falls links 13 to a traveling machine body in such a way that the lawn mower is changeable from a nonoperating state of floating on the ground to a floating state of ground and following in a ground state by empty weight by drive of a hydraulic cylinder 11. In the floating state, a ground pressure reducing hydraulic circuit for providing the hydraulic cylinder 11 with hydraulic pressure for rise operation not enough to raise the lawn mower 1 is fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lawnmower in which a lawnmower is vertically movable with respect to a traveling machine body.

[0002]

2. Description of the Related Art Generally, during lawnmower operation, the lawn mower is designed so that the weight of the lawn mower can be received and supported by a grounding wheel supported by the lawn mower while keeping track of the weight of the lawn mower to maintain a constant cutting height. When the grounding load is large and the damage to the lawn is severe, a spring is inserted between the lawn mowing device and the traveling machine body, and the entire lawn mowing device is lifted upward by the spring to urge the grounding load. Was configured to reduce.

[0003]

However, in the above-mentioned conventional structure, when the lawnmower has a large weight like a hydraulic motor driven multiple reel mower, the lifting urging spring has a large urging force. Must be configured as a large spring with a large spring on the upper side of the lawn mowing device, and there is a risk that it will come into contact with the branches of a standing tree. When the device is replaced with a new one, it is necessary to replace the spring with one having a different urging force each time, which increases the number of necessary accessory parts, which causes troublesome parts management. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems in a lawnmower of this type by effectively utilizing an elevating hydraulic mechanism that is generally arranged to float the lawnmower above ground in a non-working state.

[0004]

A feature of the present invention is that a traveling machine body is driven by a hydraulic cylinder via an elevating link to switch between a non-working state in which the vehicle is levitated to the ground and a floating state in which the vehicle is grounded to follow its own ground. It is characterized in that the lawnmower is connected to be movable up and down, and in the floating state, there is provided ground pressure reducing means for applying to the hydraulic cylinder an oil pressure on the ascending operation side which is not sufficient to lift the lawnmower.

[0005]

In the non-working state, the lawn mowing device can be greatly floated above the ground by driving the hydraulic cylinder so that the lawn mowing device does not interfere with the traveling of the aircraft. It is possible to continue the lawn mowing work while effectively maintaining a predetermined cutting height while following the ground contact with
At this time, the ground pressure of the lawnmower can be reduced as compared with the case where the lawnmower is grounded by its own weight by applying to the hydraulic cylinder a hydraulic pressure on the rising side that does not lift the lawnmower from the ground. Therefore, the damage to the grass can be effectively suppressed. Moreover, since the ground pressure reducing means is interposed in the hydraulic circuit system, even a lawnmower adopting a working mode in which the lawnmower is connected to the front portion of the traveling body,
There is no need to provide any member on the upper side of the lawnmower.

[0006]

Therefore, the ground pressure can be reduced without mounting an extra member on the outer side of the upper part of the lawnmower, and contact with an external object such as a branch of a standing tree to damage it. The lawn mowing work can now be carried out without causing any adverse effects on the lawn. Moreover, when the lawnmower is replaced with another type having a different weight, there is an advantage that the ground pressure can be easily adjusted by adjusting the hydraulic pressure in the hydraulic circuit system.

[0007]

Embodiments will be described below with reference to the drawings. Figure 1
Shows a riding lawn mower. This lawnmower is configured by connecting a lawnmower 1 to a front portion of a riding type traveling body so as to be able to move up and down. The traveling machine body is provided with a boarding operation unit 2 in the front part of the machine body, a prime mover 3 in the rear part thereof, and a non-steering front left and right front wheel 4 and a steering left and right rear wheel 5 respectively. It is configured as a wheel drive type. The left and right rear wheels 5 are hydraulic cylinders (not shown) based on the operation of the steering wheel 6.
The steering system is configured so as to oscillate by steering, and the drive system is configured so that the rotational peripheral speed becomes higher than the peripheral speed of the front wheels 4 when the steering oscillates by a predetermined angle or more. A hydraulic oil tank 8 is provided on the lower rear side of the left front wheel fender 7, and the hydraulic oil tank 8 is configured to be located closer to the inside of the vehicle than the outer end of the front wheel 4.

The lawnmower 1 is, as shown in FIG.
One reel mower 9a is provided in the center part on the front side, and two reel mowers 9b, 9c are provided in parallel behind it and hydraulic motors 10a, 10b, 10 are provided respectively.
It is configured to be rotationally driven by c, and the whole is configured to be lifted and lowered by the hydraulic cylinder 11. More specifically, as shown in FIG. 3 to FIG. 5, a pair of left and right lifting links 13, 13 pivotally supported on the front part of the machine body frame 12 of the traveling machine body so as to be vertically swingable around the horizontal axis X1 is used as a hydraulic cylinder. A lift arm 14 which is rotationally driven by 11 can be driven up and down through an elongated hole interchange 15 and can be freely retracted upward by an amount corresponding to the elongated hole in a grounded state. This lifting link 1
A support frame 16 having a substantially T-shape in plan view is provided at the front end portions of the reference numerals 3 and 13.
It is connected with the insertion pin to prevent it from coming off. A central first reel mower 9a is provided at the front end of the support frame 16.
Is supported so as to freely swing around the front-rear axis and the horizontal axis, and the front-rear axis Y1 is provided on the left and right sides of a pair of brackets 17 and 18 fixedly extending in the left-right lateral direction from the front-rear midway portion of the support frame 16. Swing arms 19 and 2 that can swing up and down around
0 is pivotally connected, and the left and right second and third reel mowers 9b and 9c are supported by the tip ends of the swing arms 19 and 20 so as to be freely swingable around the longitudinal axis and the lateral axis. As shown in FIG. 9, the swing support structure of each reel mower 9a, 9b, 9c has a support frame 16 or swing arms 19, 2 as shown in FIG.
Front and rear facing support shaft 2 that is internally fitted to a support portion such as a 0 pivot support boss portion
1. A tubular member 22 is fitted on the outer surface of the tubular member 22 so as to be rotatable relative to the tubular member 22.
2 is a horizontal axis X intersecting with the axis Y2 of the front and rear support shaft 21 at one point
Left and right support shafts 23 having two are provided in a projecting manner, and a horizontal cylindrical portion 26 fixedly attached to each of the left and right support shafts 23 via a connecting tool 25 is attached to a cover case 24 of the reel mower so as to be relatively rotatable.
It is structured so that it can swing back and forth and left and right to follow the ground contact.
The horizontal tubular portion 26 is arranged so as to be located in front of the machine body with respect to the center of gravity of each reel mower in a side view.

As shown in FIGS. 6 and 7, the reel mowers 9a, 9b and 9c each support a standing roller 32 for standing up fallen turf over the entire cutting width in the front part and a cylindrical rear roller in the rear part. 33 is supported. The upright roller 32 is configured such that a small diameter portion and a large diameter portion are alternately formed at predetermined intervals on a support shaft 35 that is laid across the left and right support members 34, 34 so as to exert the action of causing fallen grass. , Left and right sides 32
A is made of iron, and the central side 32b is made of synthetic resin. The rear roller 33 has a ferrous wheel body 33a on both left and right sides of a support shaft 37 which is provided over the left and right support members 36, 36.
And a synthetic resin cylindrical body 33b are externally fitted over the ring bodies 33a to reduce the weight. As shown in FIG. 8, a fixed blade 39 is attached to a support member 38 which is erected and extended over the right and left side walls of the cover case 24, and a cut portion made of a synthetic resin material having an oblique guide surface is provided above the support member 38. A turf guide member 40 is provided.
Further, each of the rollers 32 and 33 is configured to be integrally movable up and down relative to the cover case 24. That is, the left and right supports 36, 36 and the left and right support members 34, 34
Each of them is integrally connected by a connecting tool 41, and is vertically moved by a screw type height adjusting mechanism 42 so that the cutting height can be changed.

The swinging arms 19 and 20 have a working posture in which they are projected laterally and a retracting posture in which they are swung upward by hydraulic cylinders 43 and 44 which are vertically arranged between the brackets 17 and 18, respectively. When the swing arms 19 and 20 are oscillated upward, the stopper 45 in a fixed position contacts the horizontal tubular portion 26 during the upward swing of the swing arms 19 and 20. It is configured so that the upward tilt angle is increased to increase the storage amount. The stopper 45 is composed of a hollow roller so as to smoothly act on the cylindrical horizontal tube portion 26.
The electromagnetic hydraulic control valve block V1 for the hydraulic cylinders 43, 44 is mounted and fixed on the mounting plate 46 mounted and fixed over the brackets 17, 18, and the second and third reel mowers 9b. , 9c for driving the rotary drive motors 10b, 10c of the reel mowers 9b, 9c slightly rearward of the brackets 17 on the inner side of the body of the reel mowers 9b, 9c. The support frame 16 and the bracket 17, which are located at, are effectively inserted into the recessed space. In addition, the hydraulic motor 10 for driving the rotation of each reel mower
The hydraulic control valve block V2 for a, 10b and 10c is also mounted and fixed on the mounting plate 46.

FIG. 10 shows a lifting hydraulic circuit. While the pressure oil from the hydraulic pump 47 is supplied to the entire first hydraulic cylinder 11 for lifting and lowering through the three-position switching valve 48 of the manual switching type, when the switching valve 48 is in the neutral position or the raising operation position, A hydraulic circuit is configured to supply pressure oil to the second and third hydraulic cylinders 43 and 44 for raising and lowering the second and third reel mowers 9b and 9c. Then, in a floating work state in which each reel mower freely moves up and down while following the ground contact by its own weight, each hydraulic cylinder 11, 43,
There is provided a ground pressure reducing means A for applying a hydraulic pressure on the ascending operation side, which is not sufficient to lift the lawnmower 1, with respect to 44. More specifically, the first oil passage L for supplying and discharging hydraulic oil to and from the first hydraulic cylinder 11 is provided on the lower side of the flow passage of the switching valve 48.
1 and a second oil passage L2 which serves as a flow passage for pressure oil from the hydraulic pump 47 in the floating state, and a variable throttle valve 49 for changing and adjusting the discharge oil flow rate in the first oil passage L1 and rising. A check valve 50 that allows the flow of the working pressure oil is arranged in parallel. Then, a check valve 51 that allows only the flow of pressure oil from the second oil passage side to the lower side of the second oil passage L2 and the intermediate portion between the variable throttle valve 49 and the hydraulic cylinder 11 of the first oil passage L1. Is installed. By doing so, in the floating state, the pressure oil from the hydraulic pump 47 flows from the switching valve 48 to the second oil passage L2,
The oil is drained to the hydraulic oil tank 8 via the check valve 51 and the variable throttle valve 49. As a result, back pressure is applied to the hydraulic cylinder 11 by the variable throttle valve 49 due to the throttling action, and the hydraulic pressure on the ascending operation side acts.
This hydraulic pressure on the operating side can be changed and adjusted by manually adjusting the throttle amount of the variable throttle valve 49. Further, the control valve block V1 for the second and third hydraulic cylinders 43, 44 is 5
It is composed of individual electromagnetic control valves, and is constructed so that the pressure oil from the switching valve 48 is supplied to the pump port P of this control valve block, and is discharged from the tank port T to the hydraulic oil tank 8. The variable throttle valve 52 is provided in the oil discharge passage L3 connecting to the hydraulic oil tank 8. In the floating state, the main first solenoid valve 53 is switched to the oil discharge side, and the second and third oil discharge valves are used. Since the solenoid valves 54 and 55 are set in the fluidized state, the pressure oil from the hydraulic pump 47 flows from the pump port P to the hydraulic oil tank 8 via the first solenoid valve 52 and the oil discharge passage L3 and is drained. However, in the oil passage on the hydraulic cylinder side, a back pressure is generated by the throttling action of the variable throttle valve 52, and this pressure acts as the hydraulic pressure on the ascending side. Moreover, this hydraulic pressure on the operating side can be changed and adjusted by manually adjusting the throttle amount of the variable throttle valve 52. The check valve 51 and the variable throttle valve 49 constitute a ground pressure reducing means A for the first hydraulic cylinder 11, and the variable throttle valve 52 constitutes the second and third hydraulic cylinders 4.
A ground pressure reducing means A for 3, 44 is constructed. Since the force in the lifting direction of the reel mower as described above is applied to the horizontal tubular portion 26 located on the front side of the center of gravity of each reel mower, each reel mower is biased upward in the forwardly raised state, Standing roller 32
As a result, it becomes possible to suppress shaving and damage to the grass.

It should be noted that reference numerals are added to the claims for facilitating the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

[Figure 1] Overall side view of the lawn mower

[Figure 2] Overall plan view of the lawn mower

[Fig. 3] Side view of the lawnmower

FIG. 4 is a plan view of the lawnmower.

FIG. 5 is a front view of a storage operation unit.

FIG. 6 is a side view of the reel mower.

FIG. 7 is a partially cutaway plan view of the reel mower.

FIG. 8 is a side view of a fixed blade mounting portion.

FIG. 9 is a perspective view of a reel mower support mechanism.

[Fig. 10] Hydraulic circuit diagram

[Explanation of symbols]

 1 Lawn mowing device 11 Hydraulic cylinder 13, 13 Lifting link A Ground pressure reducing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Okura 64, Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Junji Miyata, 64, Ishizukita-machi, Sakai City, Osaka Prefecture (72) Inventor Minoru Fukuda 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Inventor Kazuo Samejima 64, Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd.

Claims (1)

[Claims] 1. An elevating link (13), (1
By driving the hydraulic cylinder (11) through 3), the lawn mowing device (1) is connected so that it can be moved up and down by switching between a non-working state in which it floats above ground and a floating state in which it follows the ground in its own weight grounding state. At
A lawn mower equipped with a ground pressure reducing means (A) for applying a hydraulic pressure on the ascending side to lift the lawnmower (1) to the hydraulic cylinder (11).