JP2000342039A - Riding lawn mower - Google Patents

Abstract

(57) [Problem] To provide a riding lawn mower in which a lawn mowing device can be freely connected to a vehicle body so as to be able to move up and down in a state in which the lawnmower does not swing easily, and a lifting and lowering operation mechanism is advantageously obtained in terms of structure and the like. A mower deck (21) of a lawnmower (10) is connected to a traveling vehicle body (10) via a pair of left and right front swing links (31) and a pair of left and right rear swing links (32). The left and right front swing links 31 are connected to the traveling vehicle body 10.
Are supported by the left and right body frame portions 11a and 11a, respectively, so as to be vertically swingable. The left and right rear swing links 32 are connected to the left vehicle body frame 1.
1a and the right side of the vehicle body frame portion 11a, and is supported by one rotating shaft 16 located below the driver's seat 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a riding type in which a lawnmower is connected between a front and a rear wheel of a traveling vehicle body having a pair of left and right freely rotatable front wheels and a freely drivable rear wheel, and a driving seat. Related to lawn mowers.

[0002]

2. Description of the Related Art There has been a riding lawn mower described above, for example, as shown in FIG. That is, a front swing link 31 and a rear swing link 32 are provided between front and rear wheels of a traveling vehicle body including the front wheel 1 and the rear wheel 2 so as to be vertically swingable by the vehicle body. The interlocking rod R is connected between the arm part provided to be able to swing integrally and the arm part provided to be able to swing integrally with the rear swing link, and the front swing link 31 and the rear swing link 32 In some cases, the end side is connected to a mower deck 21 of a lawnmower 20 via a chain C. That is, the front swing link 3
By swinging the first or rear swing link 32, the front swing link 31 and the rear swing link 32 swing in conjunction with each other due to the interlocking action of the interlocking rod R, and the lawnmower 20 travels. It goes up and down with respect to the vehicle body.

[0003]

Conventionally, when the vehicle starts running or stops running, the mowing device travels due to the chain connecting the front swing link and the rear swing link to the lawn mowing device. It was easy to swing back and forth and left and right with respect to the body. For this reason, the interval between the front and rear wheels needs to be large in proportion to the size of the lawn mower so that the lawn mower does not hit the front wheel or the rear wheel even if the lawnmower swings back and forth or left and right. SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to raise and lower a lawn mowing device by swinging a front swing link and a rear swing link, and to narrow a front and rear wheel interval in proportion to the size of the lawn mower. It is an object of the present invention to provide a lawn mower in which a mechanism for operating the device to move up and down and a driving unit can be advantageously obtained in terms of strength and structure.

[0004]

The constitution, operation and effect of the invention according to claim 1 are as follows.

[0005] A riding lawn mower in which a lawnmower is connected between the front and rear wheels of a traveling vehicle body having a pair of left and right idle front wheels and a freely drivable rear wheel and a driver seat is provided. A pair of left and right front swing links which are respectively supported on one and the other of the pair of left and right body frame portions of the traveling vehicle body so as to be vertically swingable, and are rotatable over one and the other of the pair of left and right body frame portions. A pair of left and right rear swing links are supported and supported by a single horizontal rotation support shaft located below the driver's seat, and the turf is provided at the free end of the pair of left and right front swing links. The front end side of the mowing device is connected to the free end side of the pair of left and right rear swing links so that the rear end side of the lawn mowing device is relatively rotatable.

[Operation] The body frame portion, the front swing link, the rear swing link, and the lawn mower constitute a four-link mechanism. Thus, if one of the front swing link and the rear swing link is operated to swing with respect to the body frame portion, the other swings in conjunction with the other, and the lawnmower moves up and down with respect to the traveling body. I do. In addition, even if the lawn mowing device swings back and forth or left and right with respect to the body frame due to the flexibility at the connecting portion between the mowing device and the swing link and other connecting portions, the swinging motion is the same as before. The mowing device can be connected to the traveling vehicle body so as to be able to move up and down so as to be smaller than the swing motion caused by the connecting chain.

[0007] The portion supporting the front swing link of the traveling vehicle body is located near the feet of the driver. For this reason, when one support shaft is supported over one and the other of the left and right vehicle body frame portions, and the left and right front swing links are supported by the support shaft, the support shaft moves below the foot in the lateral direction of the vehicle body. As a result, the shape of the footrest space tends to be complicated due to the support shaft.
Even when the floor plate is provided above the support shaft, the shape of the upper surface of the floor plate tends to be complicated due to the support shaft. That is, the footrest space or floor surface is likely to be difficult to use, for example, it is difficult to place a foot or to walk. On the other hand, since the left and right front swing links are separately supported by the left and right vehicle body frame portions, a support shaft for the left front swing link and a support shaft for the right front swing link are provided. Separate support shafts and support them separately on the left and right body frame parts, eliminating the support shaft that passes under the feet and the floor plate in the lateral direction of the vehicle, making the footrest space and the floor plate simple in shape The swing link is swingably supported by the vehicle body.

Since the left and right rear swing links are supported by a single rotating support shaft supported over the left body frame portion and the right body frame portion, the left body frame is separated from the left and right separate support shafts. The rear swing link is supported while the support shaft is supported by the left and right body frame parts, and the rear swing link is firmly supported, as compared to supporting the rear swing link and the right body frame part separately. It is swingably supported by the body frame. Also, by connecting an operating mechanism for raising and lowering the lawn mower to the vehicle body to the rotating support shaft, the operating force of the operating mechanism is transmitted to the left and right rear swing links by the rotating support shaft, and the left swing If the left and right rear swing links are swung at a stroke while keeping the movement of the moving link and the right rear swing link from shifting, the mowing device may be tilted to the left or right. It can be raised and lowered smoothly so that it does not occur. Since the rotation support shaft is located below the driver's seat, it is possible to prevent the footrest space and floor plate for the rotation support shaft from having a complicated shape.

[Effect] Therefore, the lawn mower can be moved up and down with respect to the vehicle body by swinging the front swing link or the rear swing link. In addition, the lawnmower is less likely to swing back and forth and left and right than before, and the distance between the front and rear wheels is smaller than the size of the lawnmower, so that the entire lawn mower can be made compact so that it can be easily operated or handled.
In addition, the driving unit is formed in a state in which it is easy to use, for example, the foot is easy to put on or walk, so that driving and getting on and off can be performed easily. Furthermore, the rear swing link is firmly supported by the vehicle body and the lawn mower is firmly supported. With a relatively simple operation structure that only requires connection, the mower can be smoothly lifted and lowered to obtain an excellent condition in terms of structure and operation.

The construction, operation and effect of the invention according to claim 2 are as follows.

[0011] In the configuration according to the first aspect of the present invention, the lawn mower is connected to one of the pair of left and right front swing links and the rear swing link and the lawn mowing device. A long connecting hole is provided for connecting the rocking link and the lawnmower in a state in which it is allowed to move in the vertical direction of the vehicle body.

[Operation] When a pushing force is applied to the lawn mowing device, such as when the wheel enters the recessed portion or the lawn mowing device climbs over the raised portion, the lawn mowing device moves with respect to the swing link for the connecting slot. Work while reducing the impact force applied to the lawn mower from the ground side.

[Effect] The impact force applied to the lawn mower colliding with the ground is reduced, and the lawn mower is hard to swing back and forth or left and right. It is easier to avoid.

The structure, operation and effect of the invention according to claim 3 are as follows.

[0015] [Structure] In the structure of the invention according to claim 1 or 2, a lifting operation mechanism is connected to the rotating shaft, and the rotating shaft is rotated by the lifting operation mechanism to form a pair of right and left rear swing links. By swinging the
The pair of left and right front swing links are swung together with the rear swing link so that the lawn mowing device can be raised and lowered with respect to the traveling vehicle body.

[Operation] When the raising / lowering operation mechanism is operated, the rotation support shaft is rotated, and the left and right rear swing links are swung at once so that the movement of the two swing links does not shift. The swing link is linked with the rear swing link via the lawn mowing device, and swings together with the rear swing link, so that the lawn mowing device moves up and down.

[Effect] With a relatively simple operation structure in which the lifting operation mechanism is simply connected to the rotation support shaft of the rear swing link,
By swinging the right and left rear swing links and the front swing link, the lawn mower can be smoothly moved up and down.

The structure, operation and effect of the invention according to claim 4 are as follows.

[Structure] In the structure of the invention according to any one of claims 1 to 3, an urging means for applying an upward urging force to the rear swing link is attached to the rotary support shaft.

[Operation] When the lawn mowing device is raised, a biasing means applies a rising biasing force to the left and right rear swing links via the rotating support shaft, and the biasing force is used as an auxiliary force for the lifting operation. The lifting operation is performed while reducing the lifting operation force applied by the lifting operation mechanism.

[Effect] When raising the lawn mower, the upward operation can be easily performed using the urging force of the urging means as an auxiliary force.

The structure, operation and effect of the invention according to claim 5 are as follows.

[Structure] In the structure of the invention according to any one of claims 1 to 4, the pair of left and right front swing links are connected to a connecting point of the front swing link to a vehicle body frame and to a lawn mower. It has a length adjustment unit that changes the distance from the connection point.

[Advantage] When the length adjusting portions of the left and right front swing links are adjusted, the distance between the connection point of each front swing link to the vehicle body frame and the connection point to the lawn mower changes. Then, the lawn mowing device swings up and down with respect to the vehicle body around the connecting point to the rear swing link as the swing center, and the connecting posture of the lawnmower to the vehicle body changes. By providing the rear swing link with a length adjusting section and adjusting the length adjusting section to adjust the connection point interval of the rear swing link, the lawn mower can also swing the connecting point to the front swing link. It swings up and down with respect to the car body as the center of motion, and the connection posture of the lawnmower with respect to the car body changes.However, obstacles when operating the length adjustment unit such as the rear wheel fender are located near the rear swing link. In many cases, there are vehicle body parts that are apt to be damaged, which makes it difficult to perform an adjusting operation. On the other hand, in the case of the front swing link, since there are relatively few vehicle body parts near the front swing link, the connecting position of the lawnmower can be adjusted by operating the length adjusting unit relatively easily and easily.

[Effect] In the event that there is a problem in the connection posture of the lawn mowing device due to a manufacturing or assembling error of the oscillating link, or due to work or storage reasons, or a change in the connection posture is required. Change the connection position of the front swing link to change the connection position of the lawnmower to the desired position, and move the lawn mower up and down smoothly without rattling or twisting, or to the desired connection position. Can be adjusted to rise. In addition, in performing this adjustment, the length adjustment section can be easily and easily operated at the front portion of the vehicle body, which is not easily affected by operation obstacles, and can be quickly performed.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a pair of left and right front wheels 1, 1 is provided at a front end portion so as to freely rotate, and a pair of left and right rear wheels 2, 2 can be driven to a rear end side. A driving unit having an engine 3 located slightly rearward of the axle center of the rear wheel 2 is provided at a rear portion of the traveling vehicle body 10 provided for the vehicle body 1.
A driving unit having a driving seat 4 located slightly forward of the axle center of the rear wheel 2 and a driving unit floor plate 6 supported on the front end side of the traveling vehicle body 10 is provided on the front side of the driving unit of the rear wheel 2. A lawn mowing device 20 having a mower deck 21 and the like is connected between the front and rear wheels of the vehicle body 10 via a link type connecting mechanism 30 so as to be lifted and lowered. It is configured to transmit rotational power to the lawnmower 20 via the rotating shaft 7 to constitute a riding lawn mower.

In addition to the mower deck 21, the lawn mower 20 includes a plurality of rotary mowing blades 22 arranged in the mower deck 21 in the vehicle body lateral direction, and a gauge wheel attached to the front and rear sides of the mower deck 21. 23 are provided. That is, the lowering operation of the link type coupling mechanism 30 causes the lawnmower 20 to move downward with respect to the traveling vehicle body 10 to travel the vehicle body. Then, each of the plurality of rotary mowing blades 22 is rotated around the vertical axis of the vehicle body by the driving force from the engine 3, and the mounting height of the gauge wheel 23 to the mower deck 21 or the travel of the lawn mowing device 20. The lawn mowing is performed at the mowing height determined by the lifting height of the vehicle body 10.

As shown in FIG.
Are a pair of left and right vehicle body frame parts 11a
11a, a front connecting frame portion 11b connecting the front end portions of the left and right body frame portions 11a, 11a, and a rear connecting frame portion connecting the rear end portions of the pair of left and right body frame portions 11a, 11a. 11c, a pair of right and left rear main frame portions 12a, 12a having a front end connected to the rear connection frame portion 11c of the front body frame 11, and The rear body frame 12 is provided with a seat support frame portion 12b and the like extending over the front end portions of the left and right rear main frame portions 12a, 12a. The left and right body frame portions 11a of the front body frame 11 are end portions of a grooved sheet metal material which is bent and formed such that both end portions are in the vehicle front-rear direction and a middle portion is in the vehicle lateral direction when viewed in the vehicle vertical direction. Prepared and connected rear frame 11c of front body frame 11
Is formed in the middle part of the bent groove type sheet metal material. Left and right rear main frame portions 12 of the rear body frame 12
a is made of a plate-shaped sheet metal material arranged so that the width direction is the vehicle body vertical direction and the sheet thickness direction is the vehicle body width direction, and the seat support frame portion 12b is a groove-shaped or plate-shaped sheet metal material. Created in combination.

The front wheel support 13 that supports the left front wheel 1 so as to freely rotate is connected to one end, and the front wheel support 13 that supports the right front wheel 1 so as to freely rotate is connected to the other end. An intermediate portion of a front wheel support frame 14 that supports the left front wheel 1 at one end and the right front wheel 1 at the other end so as to freely rotate is connected to the front connection frame portion 11b of the front body frame 11. is there. Both the front wheel support 13 on the left front wheel 1 and the front wheel support 13 on the right front wheel 1 are mounted on the boss 14a of the front wheel support frame 14 by the axle center 1 of the front wheel 1.
caster shaft core 13a shifted in the horizontal direction with respect to a
Are connected so that they can freely rotate around. Thus, the left and right front wheels 1, 1 are supported by the front end of the traveling vehicle body 10 via the front wheel support 13 and the front wheel support frame 14, and the mounting direction of the left and right front wheels 1, 1 with respect to the front wheel support frame 14 is around the caster shaft center 13a. It is a caster wheel that changes freely.

The transmission 6 is provided with a pair of continuously variable transmissions for transmitting the rotational output of the engine 3 to the left rear wheel 2 and the right rear wheel 2 respectively. Both the continuously variable transmission for transmitting power to the left rear wheel 2 and the continuously variable transmission for transmitting power to the right rear wheel 2 are driven by a hydraulic pump driven by the engine 3 and pressure oil from the hydraulic pump. It is configured as a hydrostatic stepless transmission comprising a hydraulic motor that outputs rotational power to the wheel 2. By changing the swash plate angle of the hydraulic pump, the rear wheel 2 is moved forward or backward. When the vehicle is driven or power transmission is stopped to stop rear wheel drive, and the vehicle is driven to either the forward side or the reverse side, the transmitted rotational power can be continuously changed. That is, both when the rear wheel 2 is driven to the forward side and when the rear wheel 2 is driven to the reverse side, the drive can be performed with the stepless speed change.

As shown in FIG. 3 and the like, a left traveling lever 8a linked to the operating portion of the continuously variable transmission of the left rear wheel 2 includes:
The right traveling lever 8b of the right rear wheel 2, which is linked to the operation section of the continuously variable transmission, is provided separately on the left side and the right side on the front end side of the driving seat 4 of the driving section. That is, the left traveling wheel 8 is operated to swing forward and backward by shifting the continuously variable transmission by swinging the left traveling lever 8a in the front-rear direction of the vehicle body, or to stop and operate the right rear traveling wheel. The right rear wheel 2 is driven or shifted to the forward side or the reverse side by operating the lever 8b in the vehicle longitudinal direction to shift the continuously variable transmission, and the stop operation is performed. When the left and right rear wheels 2 and 2 are driven at the same speed to the forward side or the reverse side by operating the left traveling lever 8a and the right traveling lever 8b in this manner and the speed is changed, the left and right front wheels 1 and 1 are contacted by the ground and the rear wheel 2. For propulsion, the vehicle is mounted in a straight forward or straight backward direction, and the vehicle body travels forward or backward while traveling at a variable speed. When the left and right rear wheels 2, 2 are driven forward or backward at different speeds, or when one of the left and right rear wheels 2, 2 is driven forward and the other is driven backward, the left and right front wheels 1, 1 are brought into contact with the ground. For the propulsion by the rear wheel 2, it turns around the caster shaft core 13a to be in the mounting direction for the lateral running, and the speed difference is determined by the speed difference between the left and right rear wheels 2, 2 and the driving direction. And the direction is changed by the turning radius determined by the driving direction. The left and right traveling levers 8a and 8b are used to open the front of the seat 4 when the driver sits on the driver's seat 4 or when the driver leaves the driver's seat 4, as shown by a two-dot chain line in FIG. 4 is retracted to the lateral outside from the front.

As shown in FIG. 2 and the like, the link type linking mechanism 30 is connected to the front body frame 11 of the traveling body 10.
A pair of left and right front swing links 31 and 31 separately located on both lateral outer sides of a front end of the vehicle body, and a pair of right and left rear swing links separately located on both lateral outer sides of a rear end of the front body frame 11. 32, 32.

As shown in FIGS. 1, 2 and 5, etc., a pair of left and right front swing links 31, 31 is provided with a boss portion 31a formed by welding a cylindrical body to the base end side thereof. A connecting portion 31b formed by welding a yoke is provided on the free end side. A boss portion 31a on the base end side of the left front swing link 31 is provided with a cylindrical body at the front end portion of the left body frame portion 11a of the pair of left and right body frame portions 11a of the front body frame 11. Is connected to the boss portion 11d formed by welding by a connecting shaft 15 extending in the lateral direction of the vehicle body and passing through the boss portions 31a and 11d. Connection part 31b on the free end side of left front swing link 31
Are a pair of left and right front connection brackets 24 erected at the front end of the mower deck 21 on the upper surface side of the mower 20.
The front connecting bracket 24 is connected to the left front connecting bracket 24 so as to be relatively rotatable by a front connecting pin 33 in a vehicle body sideways direction that penetrates the connecting bracket 24 and the connecting portion 31b. Boss 31a on the base end side of right front swing link 31
Is a right body frame portion 11 of the pair of left and right body frame portions 11a, 11a of the front body frame 11.
A boss 11d formed by welding a cylindrical body to the front end of a
The two bosses 31a and 11d are connected to each other by a connecting shaft 15 extending in the lateral direction of the vehicle body and inserted through the boss portions 31a and 11d. The connecting portion 31b on the free end side of the right front swing link 31 is connected to the lawn mower 2
0 of the pair of left and right front connection brackets 24 of the mower deck 21.
The connecting bracket 24 and the connecting portion 31b are rotatably connected to each other by a front connecting pin 33 which is oriented laterally to the vehicle body. The connection shaft 15 connecting the left front swing link 31 to the left body frame portion 11a is separate from the connection shaft 15 connecting the right front swing link 31 to the right body frame portion 11a. Created on the connection axis. A pair of left and right rear swing links 32, 32 is provided with a boss 32a formed by welding a tubular body to the base end side thereof, and a connecting portion 32b formed by welding a yoke to each free end side thereof. It is. The boss portion 32a on the base end side of the left rear swing link 32 is provided on the rear end portion of the left body frame portion 11a of the pair of left and right body frame portions 11a of the front body frame 11. The boss portion 11e formed by welding the body and the boss portion 11e formed by welding a cylinder to the rear end of the right body frame portion 11a are rotatably attached to each other and below the front end of the driver's seat 4. The boss portion 11 of the vehicle body frame portion 11a on the left side of the one body-side horizontal rotation support shaft 16 disposed so as to be positioned at
e, it is externally fitted to the end of the support shaft protruding laterally outward from the vehicle body, and is locked so as to be integrally rotated by a connecting bolt and to be prevented from coming off. The connecting portion 32b on the free end side of the left rear swing link 32 is a left side of a pair of left and right rear connecting brackets 25, 25 erected at the rear end portion on the upper surface side of the mower deck 21 of the lawnmower 20. The connecting bracket 25 and the connecting portion 3
2b is connected rotatably relative to the vehicle by a rear connecting pin 34 facing the vehicle sideways. Right swing link 32
The base end side boss portion 32a of the rotation support shaft 16 is externally fitted to a shaft end portion protruding outward from the vehicle body from the boss portion 11e of the right body frame portion 11a of the rotation support shaft 16 and integrally rotated by a connection bolt, In addition, it is locked so as not to come off. The connecting portion 32 b on the free end side of the right swing link 32 is connected to the mower deck 21 of the lawn mower 20.
Of the left and right pair of rear connection brackets 25, 25, the connection bracket 2
5 and the connecting portion 32b are connected to each other by a rear connecting pin 34 facing the vehicle sideways so as to be relatively rotatable.

Thus, the pair of left and right front swing links 31 of the link type coupling mechanism 30 are respectively provided at the front end of the left body frame 11a of the traveling vehicle body 10 and the front end of the right body frame 11a. Separately, the connecting shaft 15 is supported so as to be able to swing up and down by using the connecting shaft 15 as a support shaft.
0 of the mower deck 21 with the front body frame 11
And a pair of left and right rear swing links 3
The mower deck 2 and 32 are vertically swingably supported by a pair of left and right rear end portions of the vehicle body frame 11a of the traveling vehicle body 10 via one rotating shaft 16. The rear end 21 is connected to the front body frame 11 so as to be able to move up and down. Therefore, the front vehicle body frame 11 of the traveling vehicle body 10, the front swing link 31,
Rear swing link 32 and mower deck 2 of lawnmower 20
1 constitutes a quadruple link mechanism.

As shown in FIG. 4, a sector-shaped support shaft gear 4 is connected to a portion of the rotary support shaft 16 located on the inner side of the vehicle body frame portion 11a on the right side of the vehicle body frame portion 11a.
1, a fan-shaped lever gear 42 meshing with the support shaft gear 41, and a support shaft 4 having one end connected to the lever gear 42 so as to be integrally rotatable and supporting the lever gear 42.
A raising / lowering operation for raising / lowering the lawn mower 20 with respect to the traveling vehicle body 10 by a raising / lowering lever 44 which is connected to the other end side of the driving unit 3 so as to be integrally rotatable and is located on the right side of the driving unit. A mechanism 40 is configured. The operation lever 4
4 has a lock pin 45 slidably supported in the direction of the stem of the operation lever 44, and a plurality of notches 46a to which the lock pin 45 is engaged and disengaged. The lifting mechanism 40 is provided with a lock mechanism for fixing the operation lever 44 to a predetermined operation position by a lock member 46 supported by the vehicle body frame 11a.

A free end side of an operation arm 47 whose base end is integrally rotatably connected to a center portion of the rotation support shaft 16 in the longitudinal direction, and left and right rear main frame portions of the rear body frame 12. Spring support 4 supported by a connecting frame 12c connected between the 12a and 12a
A gas spring 49 is attached to the portion 8.
The gas spring 49 is provided with the spring receiver 48.
A cylinder tube 49a having one end connected to the cylinder tube 49a so as to be relatively rotatable, one end slidably fitted inside the cylinder tube 49a, and the other end connected to the operation arm 47.
And a cylinder rod 49b connected to the cylinder tube 49a so as to be relatively rotatable, and a gas or the like filled in the cylinder tube 49a. The charged gas projects the cylinder rod 49b from the cylinder tube 49a. Side, and the urging force causes the rotation shaft 16 to rotate.
The left and right rear swing links 32,
32 is urged so that the lawnmower 20 rises with respect to the traveling vehicle body 10. Running the lawn mower 20 on the vehicle body 10
, The cylinder rod 49b of the gas spring 49 is slid to the side where it enters the cylinder tube 49a. Thereby, the gas spring 49 enables the lowering operation of the lawnmower 20.

That is, the lawn mower 20 is connected to the traveling body 10
In raising and lowering the lock member 45, the lock pin 45 is disengaged from the notch 46a of the lock member 46 by pressing the lock release button 45a protruding from the head of the operation lever 44, and the lock pin 45 is removed from the slot 46b. The lock mechanism enters the unlocked state. Thus, while operating the lock mechanism in the unlocked state, the operation lever 44 is operated.
Is pivoted around the axis of the support shaft 43 with respect to the lock member 46, which also serves as a member that rotatably supports the support shaft 43. Then, the lever gear 42 rotates around the axis of the support shaft 43 due to the lever operation force, and the support gear 41 is rotated by the lever gear 42 to rotate the rotary support shaft 16. The swing links 32 are operated to swing downward or upward with respect to the vehicle body frame 11a. Then, the left and right front swing links 3
1, 31 are rear swing links 32 via the mower deck 21.
, And swings in the same direction as the rear swing link 32 together with the rear swing link 32, and the lawnmower 20 moves up and down with respect to the traveling vehicle body 10. Lawn mowing equipment 2
0, the ascending operation is assisted by the ascending force of the gas spring 49, and the operation lever 44
The operation can be performed while the operation force applied to the device is relatively light.
When the lawnmower 20 is at a predetermined raised position or lowered position,
The pressing operation of the lock release button 45 a is released, and the lock pin 45 is moved to the lock spring 4 located inside the operation lever 44.
The lock member 46 is caused to enter any one of the plurality of notches 46a by the operation force 5b. Then
The locking mechanism locks the operating lever 44 so that the operating lever 44 is not operated downward by the weight of the lawnmower 20, so that the lever is locked.
0 can be locked to the operated lifting height.

As shown in FIGS. 4 and 5, a length adjusting portion 35 is provided at the base end side of each of the pair of left and right front swing links 31, 31. The length adjusting portion 35 is a screw cylinder portion 35a formed by welding a screw cylinder to a vehicle body side link portion having the boss portion 31a of the front swing link 31.
And a screw shaft portion 35b provided on a lawn mowing side link portion having the connecting portion 31b of the front swing link 31. That is, the length of the front swing link 31 is changed by relatively rotating the screw shaft portion 35b and the screw tube portion 35a to adjust the length of the screw shaft portion 35b entering the screw tube portion 35a and connecting the screw shaft portion 35b. And the front swing link 3
And a mower deck 2 of the lawnmower 20 as a connection point to the vehicle body frame 11a.
The distance D between the front connection pin 33 and the shaft center of the front connection pin 33 as a connection point with respect to 1 is changed. The screw shaft portion 35b is provided with a lock nut 36 for fixing the adjusted length of the front swing link 31 so as not to be changed by vibration or the like.

That is, the left and right front swing links 31, 31
By operating each length adjusting section 35 to change the connection point interval D, the mower deck 21 swings up and down with respect to the vehicle body with the connection point to the rear swing link 32 as the swing center, The connection posture of the lawnmower 20 with respect to the vehicle body can be adjusted.

As shown in FIG. 4, the left and right pair of front connection brackets 24, 24 and the left and right pair of rear connection brackets 25,
Each of the 25 has a connecting slot 24a, 25a. Each of the connection slots 24a, 25a is connected to the connection pin 3
3 and 34 are slidably inserted into the lawn mower 2
0 allows the front swing link 31 and the rear swing link 32 to move up and down in the vehicle body vertical direction within a stroke range determined by the length of the connecting long holes 24a and 25a. 31 and rear swing link 32
And are connected.

As a result, the front wheel 1 and the rear wheel 2 may enter the recessed portion of the ground or the gauge wheel 2 of the lawnmower 20.
3 and the mower deck 21, the obstacle climbing roller 26 provided on the front end side of the mower deck 21 rides on a raised portion or the like, and a pushing force is applied to the lawn mower 20.
Rises with respect to the front swing link 31 and the rear swing link 32 due to the connection long holes 24a and 25a of the front connection bracket 24 and the rear connection bracket 25, thereby reducing the impact force applied to the lawn mower 20 from the ground side. You can work while planning.

[Alternative Embodiment] Instead of providing the connecting long holes 24a and 25a in the front connecting bracket 24 and the rear connecting bracket 25, the connecting portion 31b of the front swing link 31 and the rear swing link 32 is provided. The connection pins 33 and 34 may be embodied by providing a connection slot in which the connection pins 33 and 34 are slidably inserted. Also in this case, when an operation force acts on the lawn mower 20 from the ground side,
The lawn mowing device 20 includes a front swing link 31 and a rear swing link 32.
And work can be performed while reducing the impact force applied to the lawn mower 20.

Instead of the gas spring 49, a coil spring or a combination of a coil spring and a gas spring is used to connect the rear swing link 32 to the lawn mowing apparatus 2.
The gas springs 49 and the coil springs may be collectively referred to as biasing means 49.

[Brief description of the drawings]

FIG. 1 is a side view of the entire riding lawn mower.

FIG. 2 is a plan view of a vehicle body and a coupling mechanism.

FIG. 3 is a front view of an operation unit.

FIG. 4 is a side view of a coupling mechanism and a lifting operation mechanism.

FIG. 5 is a plan view of a left portion of the coupling mechanism.

FIG. 6 is a side view of an entire conventional riding lawn mower.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 front wheel 2 rear wheel 4 driver's seat 10 traveling body 11a body frame 16 rotating support shaft 20 lawn mower 24a, 25a connecting long hole 35 length adjusting unit 40 elevating operation mechanism 49 biasing means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiyuki Ezaki 64 Ishizukita-cho, Sakai-shi, Osaka F-term in Kubota-Sakai Works (reference) 2B083 AA02 BA12 BA18 CA28 GA01 HA01 HA60

Claims (5)

[Claims] 1. A riding lawn mower in which a lawnmower is connected between front and rear wheels of a running vehicle body having a pair of left and right idle front wheels and a freely drivable rear wheel, and a driving seat. A pair of left and right front swing links that are vertically swingably supported by one and the other of the pair of left and right body frame portions of the traveling vehicle body, and are rotatable over one and the other of the pair of left and right body frame portions. And a pair of left and right rear swing links supported by a single rotational support shaft that is located below the driver's seat and that is lateral to the vehicle body, and is provided at the free ends of the pair of left and right front swing links. A riding lawn mower wherein a front end of the lawn mower is connected to a free end of the pair of left and right rear swing links and a rear end of the lawn mower is relatively rotatably connected. 2. The one of the pair of left and right front swing links and rear swing links and the lawnmower allows the lawnmower to move in the vehicle body vertical direction with respect to the swing link. 2. The riding lawn mower according to claim 1, further comprising a connecting slot for connecting the rocking link and the lawn mower in a state. 3. An up-down operation mechanism is connected to the rotation support shaft, and the up-down operation mechanism rotates the rotation support shaft to swing a pair of right and left rear swing links, thereby forming a pair of left and right front swing links. 3. The riding lawn mower according to claim 1, wherein the rocking link is rocked together with the rear rocking link so that the lawn mowing device is moved up and down with respect to the traveling vehicle body. 4. The rotating shaft is provided with an urging means for applying an upward urging force to the rear swing link.
A riding lawn mower according to any one of the preceding claims. 5. A pair of left and right front swing links each having a length adjusting portion for changing an interval between a connecting point of the front swing link to a vehicle body frame and a connecting point to a lawn mower. A riding lawn mower according to any one of Items 1 to 4.