JPH0646633A - Lawn mower - Google Patents

Abstract

PURPOSE:To provide a lawn mower efficiently workable in lawn mowing work while safely travelable with narrow width in traveling on the road, also simple in lifting the entire lawn mowing device in a nearly horizontal attitude during lawn mowing work. CONSTITUTION:Three mowers are connected to a supporting frame to be driven by the 1st hydraulic cylinder 11 so as to make vertical motion relatively to the traveling machine body, and the mowers on both left and right sides are respectively supported so as to be free to rock for upward housing by the 2nd and 3rd hydraulic cylinders 43, 44 relatively to the supporting frame; during lawn mowing work, the respective mowers are designed to be in floating mode by the hydraulic cylinders 11, 43, 44 so as to make vertical motion while being in compliance with the surface of the ground, and the hydraulic pressure control for the respective 2nd and 3rd hydraulic cylinders are made by electromagnetically driving type pressurized oil feed on-off valves 50, 52 and oil discharge on-off valves 51, 53 acting 'on' by excitation driving and 'off' by spring force; the respective oil discharge on-off valves 51, 53 are automatically switched to neutrally rocked mode and the respective pressurized oil feed on-off valves 50, 52 is actuated 'on' for a specified time alone interlockingly with the changeover operation of the 1st hydraulic cylinder 11 from its floating mode to risingly driven mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
A plurality of mowers are connected to a support frame that is driven to move up and down by a hydraulic cylinder so that the mower can be moved up and down, and the mowers located on both left and right sides can be stored and swung upward by the second and third hydraulic cylinders with respect to the support frame. A lawnmower, which is supported by support arms pivotally connected to each other, and is configured to set each hydraulic cylinder in a floating state so that each mower moves up and down while following the ground contact during a lawnmower operation.

[0002]

2. Description of the Related Art In the above lawnmower, conventionally, as shown in, for example, Japanese Utility Model Laid-Open No. 2-102925, an elevating link provided on the front side of a machine body is configured to be movable up and down by a hydraulic cylinder for elevating. Three reel mowers are attached to the elevating link, and the left and right reel mowers are configured to be supported by the hydraulic cylinders so that they can be stored and rocked, and the hydraulic control for the hydraulic cylinders for storage is electromagnetically controlled on the pressure oil supply path and the oil discharge path There is a configuration in which an on-off valve is interposed, and these solenoid valves were configured to be controlled to be opened and closed by a dedicated changeover switch.

[0003]

With the above-mentioned structure, since the entire width of the lawnmower is larger than the width of the traveling body in this type of lawnmower, the right and left sides are prevented from obstructing traveling when traveling on the road. The mower is retracted and swung upward to reduce the width of the lawnmower. However,
In the lawnmower having the above structure, for example, when the entire lawnmower is slightly lifted to move over a step of concrete during lawn mowing work, the pressure oil circuit for the lifting cylinder of each mower is neutralized. Since it is necessary to lift and operate the link cylinder after setting to the state, there is a drawback that each operation of the changeover switch and the operation of switching the elevating cylinder are necessary and the operation is troublesome. Therefore, the closing operation of the electromagnetic on-off valve as described above,
Although it is possible to perform it in conjunction with the operation of the lifting cylinder, the electromagnetic on-off valve is a structure in which the opening operation is performed at high speed and quickly because the electromagnetic solenoid is excited and driven, but the closing operation is performed by the spring. There is a drawback that the response is slow compared to the speed of the opening operation. As a result, the neutral return time of each mower cylinder is delayed with respect to the manually switchable link lifting control valve, and the entire lawn mower can be lifted while the left and right mowers are hanging, and the left and right mowers are on the stepped portion. There was a possibility of catching and interfering, and there was room for improvement. The present invention aims to eliminate the above-mentioned problems.

[0004]

According to a characteristic configuration of the present invention, in the lawnmower described at the beginning, the hydraulic control for each of the second and third hydraulic cylinders is opened by excitation drive and closed by spring force. The electromagnetically driven pressure oil supply on / off valve and the oil discharge on / off valve are configured to be operated, and each of the drain oil is interlocked with the switching operation of the first hydraulic cylinder from the floating state to the ascending drive state. The electromagnetic switching valve is automatically switched to a neutral lock state, and an automatic switching means for opening the pressure oil supply switching valve for a predetermined short time is provided.

[0005]

[Function] During lawn mowing work, a plurality of mowers arranged in parallel enables efficient work with a sufficiently large mowing width, and the mowers on the left and right sides are independently grounded to the mowers on the center side. Since it can be moved up and down by following it, you can work with less cutting residue while following the unevenness of the grass. Further, when traveling on the road or the like, the mowers on the left and right sides can be greatly lifted and retracted to reduce the width of the machine body for safe traveling. When all mowers are slightly lifted to move and run in a non-working state, when the first hydraulic cylinder is operated to move up, the respective solenoid valves for drainage are automatically switched to the neutral lock state. As a result, the second and third hydraulic cylinders are automatically switched from the floating state to the neutral lock state, and the mowers on the left and right sides are fixed relative to the support frame, and the mowers are integrated. Will be operated ascending. At this time, when each of the drainage electromagnetic on-off valves is switched to the neutral lock state, it takes time due to the operation by the spring force, and the pressure oil leaks from the storage cylinders of the left and right mowers, and the left and right mowers are likely to fall. At the same time, by opening the pressure oil supply on-off valve for a short period of time at the same time, the pressure oil is replenished, and the downward descent of the left and right mowers can be effectively prevented. The whole can be lifted.

[0006]

Therefore, the lawn mowing work can be performed efficiently with a sufficiently large cutting width regardless of the unevenness of the lawn and there is little uncut residue, and the safety of road traveling can be secured while the lawn mowing work is being performed. The lifting drive of each mower can be handled with only one operation, and the operability can be improved, and moreover, the plurality of mowers can be lifted and operated efficiently in a substantially horizontal state. It has become possible to provide a lawn mower capable of preventing the harmful effects of interfering with a hanging step or the like and damaging it.

[0007]

Embodiments will be described below with reference to the drawings. Figure 1
Shows a riding lawn mower. This lawnmower is constructed 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 left and right front wheel 4 and a left and right steerable rear wheel 5 respectively driven to It is a wheel drive type. The left and right rear wheels 5 are steered by the steering cylinder 6a 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 over a predetermined angle. 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 so as 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 first hydraulic cylinder 11. More specifically, as shown in FIGS. 3 to 5, a pair of left and right elevating links 13, 13 pivotally supported on the front portion of the machine body frame 12 of the traveling machine body so as to be vertically swingable about the horizontal axis X1 is provided. A lift arm 14 which is rotationally driven by a hydraulic cylinder 11 is configured so that it 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. A support frame 16 having a substantially T-shape in plan view is connected to the front ends of the elevating links 13 and 13 by means of retaining pins to prevent the support frame 16 from coming off. A central first reel mower 9a is supported at the front end of the support frame 16 so as to be freely swingable around the front-rear axis and the horizontal axis, and is fixedly extended laterally from the middle of the front-rear direction of the support frame 16. Pair of brackets 17, 18
Swinging arms 19 and 20 which can swing up and down about the front-rear axis Y1 are pivotally connected to both left and right sides of the swinging arms 19 and 20.
The left and right second and third reel mowers 9b and 9c are supported at the tip of the shaft so as to freely swing about the front-rear axis and the horizontal axis. As shown in FIG. 8, the swing support structure of the reel mowers 9a, 9b, 9c includes a front-back support shaft 21 that is fitted in a support frame 16 or a support portion such as a pivot boss portion of the swing arms 19, 20. A tubular member 22 is fitted on the cylindrical member 22 so as to be rotatable relative to the tubular member 22, and a left and right support shaft 23 having a horizontal axis X2 intersecting the axis Y2 of the front and rear support shaft 21 at one point is projectingly provided on the tubular member 22. A horizontal tubular portion 26 is attached to the shaft 23 to a cover case 24 of the reel mower via a connecting tool 25 so as to be rotatable relative to the shaft 23 so as to swing forward, backward, leftward and rightward 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. Further, the connecting points of the swing arms 19 and 20 to the second and third reel mowers 9b and 9c are biased toward the inside of the machine so that the left and right center of gravity of each mower is located, and the first reel mower 9a is operated by the hydraulic motor 10a. In consideration of weight, the compression spring 30 pulls up and urges the weight to balance the left and right weights. Further, as shown in FIG. 7, the reel blades of the reel mowers 9a, 9b, 9c are manually rotatable from the outside of the case by a detachable rotary handle H.
The sharpness can be adjusted safely.

At the front end of the machine body, there is provided a lock mechanism R for suspending and fixing the entire lawnmower 1 in a state in which it is greatly raised. That is, as shown in FIGS. 3 and 5, a lock pin 28 that is slidable left and right by a lever 27 that can be operated from the control unit 2 is provided at the front end of the machine body, and the lock pin 28 supports the support frame of the lawnmower 1. The suspension hook 31 formed in 16 is locked to prevent the lawnmower 1 from descending. The lock pin 28 is kept in a locked state by a spring 29 so as not to come off due to vibration.

As shown in FIGS. 6 and 7, the reel mowers 9a, 9b and 9c each support a standing roller 32 for standing up fallen grass 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 constructed so as to extend over the left and right support members 34, 34 and alternately has a small diameter portion and a large diameter portion formed at predetermined intervals so as to exert the action of causing fallen grass. The rear roller 33 is erected and supported over the left and right supports 36, 36. or,
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 support members 36, 36 and the left and right support members 34, 34 are integrally connected by a round pipe-shaped connecting member 41, respectively, and the cutting height can be integrally moved up and down by a screw type height adjusting mechanism 42 to change the cutting height. It is configured as follows. The connecting tool 41 has its front and rear ends bent in a sled shape so as not to damage the grass.

The rocking arms 19 and 20 are horizontally and laterally projected by the second and third hydraulic cylinders 43 and 44, which are vertically arranged between the brackets 17 and 18, respectively. The oscillating arms 19 and 2 are configured so as to oscillate and drive in the swaying storage posture, and are moved toward the storage posture.
During the upward swing of 0, a stopper 45 in a fixed position is brought into contact with the horizontal tubular portion 26 to increase the upward tilt angle of the reel mower and increase the storage amount. The stopper 45 is composed of a rotating roller having a concave shape so as to smoothly act on the cylindrical horizontal tube portion 26. In addition, the second and third hydraulic cylinders 43 and 44
The electromagnetic hydraulic control valve block V1 is mounted and fixed on the mounting plate 46 which is mounted and fixed on the brackets 17 and 18, and the hydraulic motor 10b for rotating the second and third reel mowers 9b and 9c. , 10c are arranged slightly behind the bracket 17 on the inner side of the body of the respective reel mowers 9b, 9c, and the second and third reel mowers 9 are provided.
The support frame 16 and the bracket 17 located in the center of the left and right between b and 9c are effectively inserted into the recessed space. The hydraulic control valve block V2 for the rotary driving hydraulic motors 10a, 10b, 10c of the reel mowers is also mounted and fixed on the mounting plate 46.

FIG. 9 shows a hydraulic circuit. Pressure oil from a hydraulic pump P1 driven by an engine is supplied to the first hydraulic cylinder 11 via a steering valve mechanism V3 and a manually operated three-position switching valve 47, while the switching valve 47 is in a neutral position or a lowered position. Second, when
The lifting hydraulic circuit is configured to supply pressure oil to the hydraulic control valve block V1 for the third hydraulic cylinders 43 and 44. The hydraulic control valve block V1 is composed of five electromagnetic valves, and each electromagnetic valve is switched by the control device 48 based on the operation of the two changeover switches SW1 and SW2 provided on the side of the seat of the boarding operation unit 2. It is configured to be performed. That is, the pressure oil is the first solenoid valve 49 and the second solenoid valve 50.
Is supplied to the second hydraulic cylinder 43 via the third hydraulic valve 43, and the oil discharged from the second hydraulic cylinder 43 is discharged via the third electromagnetic valve 51. Further, pressure oil is supplied to the third hydraulic cylinder 44 via the first electromagnetic valve 49 and the fourth electromagnetic valve 52, and drain oil from the third hydraulic cylinder 44 is discharged via the fifth electromagnetic valve 53. A hydraulic circuit is configured. Each of the second to fifth electromagnetic valves 50 to 53 is an open / close valve that is excited and driven to open, and closed by a spring force. Each of the changeover switches SW1 and SW2 is provided in a three-position changeover type of ascending, neutral, and descending, and the control device 48 operates an electromagnetic on-off valve so that the left and right second and third oil cylinders 43 and 44 are correspondingly moved up and down. It controls turning on and off. More specifically, when the first changeover switch SW1 is operated to the raised position, the first electromagnetic valve 49 and the second electromagnetic valve 50 are opened, and when it is operated to the lowered position, the third electromagnetic valve 51 is opened. Similarly, the second
When the changeover switch SW2 is operated to the raised position, the first electromagnetic valve 49 and the fourth electromagnetic valve 52 are opened, and when it is operated to the lowered position, the fifth electromagnetic valve 53 is opened.

During the lawn mowing work, the hydraulic cylinders 11, 43, 44 are connected to the reel mowers 9a,
9b and 9c are configured to be set in a floating state so as to move up and down while following the ground contact, and in conjunction with the switching operation of the first hydraulic cylinder 11 from the floating state to the ascending drive state, the second and the second hydraulic cylinders are connected. The control device 48 is provided with automatic switching means A for automatically switching the three hydraulic cylinders 43 and 44 to the neutral lock state in the form of a control program. More specifically, the operation lever 54 of the three-position switching valve 47
Is provided with a detection switch SW3 for detecting that the switch is operated from the lowered position to the raised position. When the detection operation output of the detection switch SW3 is given to the control device 48, the control device 48 causes the changeover switches SW1 and SW2 to operate. Despite both being set to the lowered position, the third solenoid valve 5
The first and fifth solenoid valves 53 are closed to switch the second and third hydraulic cylinders 43 and 44 to the neutral lock state, and at the same time, the first, second and fourth solenoid valves 49, 50 and 52 are each set to a predetermined short time. Control is performed so that the opening operation is performed for a time (for example, about 0.3 seconds). This is because the switching speed to the closing operation by the spring force is slower than the switching speed by the excitation drive, and the timing delay causes the second and third reel mowers 9b and 9c to move to the first reel mower 9a. This is because it is possible to prevent the state of being slightly lowered, and to be able to drive the entire lawnmower to rise in a substantially horizontal posture.

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 mower lifting mechanism.

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

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

FIG. 8 is an exploded perspective view of a mower support mechanism.

[Fig. 9] Hydraulic circuit diagram

[Explanation of symbols]

 9a, 9b, 9c mower 11 first hydraulic cylinder 16 support frame 19, 20 swing arm 43 second hydraulic cylinder 44 third hydraulic cylinder 50, 52 solenoid valve for supplying pressure oil 51, 53 solenoid valve for discharging oil A Automatic switching means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Samejima 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Junji Miyata 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co. (72) Inventor Yasuhiro Oshima 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. (72) Minor Kyotani 64, Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. A first hydraulic cylinder (1) for a traveling vehicle body.
1) A plurality of mowers (9a), (9b) and (9c) are connected to a support frame (16) which is driven to move up and down by movability, and the mowers (9) located on both left and right sides.
B) and (9c) are pivotally connected to the support frame (16) by second and third hydraulic cylinders (43) and (44) so that they can be stored and pivoted upward. Two
0), each hydraulic cylinder (11), (43), (44) moves up and down while mowers (9a), (9b), (9c) follow the ground contact during lawnmower work. A lawnmower configured to be set in a floating state in order to achieve the above, wherein the second and third hydraulic cylinders (4
Electromagnetically driven pressure oil supply on / off valves (50) and (52) and an oil drain on / off valve (51) that hydraulically control 3) and (44) respectively are opened by excitation drive and closed by spring force. ), (5
3) and the first hydraulic cylinder (1
Interlocking with the switching operation from the floating state to the ascending drive state in 1), the drainage solenoid on-off valves (5
A lawn mower equipped with automatic switching means (A) for automatically switching (1) and (53) to a neutral lock state and opening the pressure oil supply on-off valves (50) and (52) for a predetermined short time. .