JP4901408B2 - Riding work machine - Google Patents

Description

  The present invention relates to a riding work machine such as a riding mower (riding mower) or a lawn mower used for undergrowth orchards in an orchard. The present invention relates to a riding work machine that can be performed efficiently and quickly.

  As this type of riding work machine, as seen in the following Patent Documents 1, 2, etc., the body frame is divided into a front frame and a rear frame, and both frames are connected by a joint having a pivot or the like. 2. Description of the Related Art An intermediate type (articulate type) that is relatively rotatable in a horizontal plane, that is, has two front wheels or two rear wheels as steering wheels is known.

Further, many of the riding mowers used for undergrowth orchards in orchards have a structure in which the grass cutting part is located between the front and rear wheels by front wheel steering.
As another example of a riding mower (such as a golf course lawn mower) having a different structure, there is known a grass mowing unit disposed in front of the front wheel by rear wheel steering as seen in Patent Document 2 and the like.

Japanese Utility Model Publication No. 60-156921 Japanese Unexamined Patent Publication No. 2000-270651

  However, in the above-mentioned folding type (articulate type) riding work machine, a large load is applied to the joint part connecting the front frame and the rear frame, so that the strength of the joint part must be sufficiently ensured. In addition, because it is a folding type, it is necessary to adopt a complicated structure using hydraulic pressure etc. for the engine power transmission system, etc., resulting in high cost, weight increase, complexity, etc. I was invited.

  In addition, the riding grass mower with the front wheel steering and the grass cutting part between the front and rear wheels (lower side of the center of the vehicle body) has a relatively large minimum turning radius, which is caused by the difference between the wheel turning locus and the grass cutting portion turning locus. There is a problem that uncutting is likely to occur. In addition, since there is a driver's seat directly above the cutting blade, it is difficult to cut grass under the branches of thick fruit trees and the edges of rice fields, and only the part that can actually travel through (the part that can be cut) There was also a problem of becoming.

  Further, as seen in Patent Document 2, rear wheel steering riding mowers (golf lawn mowers, etc.) having a mowing portion disposed in front of the front wheels tend to be longer in total length. Since the tail swing caused by the wheel steering becomes large, it is difficult to control the driving in the orchard where trees are complicated, and the mechanism is complicated, resulting in high costs.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to be able to perform mowing work and the like efficiently, quickly and smoothly while having a relatively simple configuration and effective turning. It is to provide a working machine.

In order to achieve the above-mentioned object, a riding mower according to the present invention basically includes a travel drive system including a prime mover such as an engine, a work drive system, a main frame in which a driver's seat and an operation system are arranged. , and a sub-frame axle of the steering wheel together when it is rotatably supported is linked to integrally rotate in a horizontal plane at the bottom of the main frame, one of the said main frame subframe while the either, provided the rolling member receiving a load on the other, it is characterized by semi-dished or reverse half dish shaped pivoting guide surface member to which the rolling member rolls are provided .

In a preferred embodiment, the front two wheels are drive wheels and the rear two wheels are steering wheels, and the axle of the rear wheel is connected to the subframe so as to be integrally rotatable.
In a more preferred aspect, the pivot center of the axle of the subframe and the steering wheel is offset in the vehicle longitudinal direction from the center of the axle.
The axle of the steering wheel is preferably swingable in a vertical plane around a center pin provided in the subframe.

In another preferred embodiment, the front two wheels are drive wheels and the rear two wheels are steering wheels, and a grass cutting portion is disposed in front of the front two wheels.
In another preferred embodiment, the rear two wheels are steered wheels and driven wheels, one of the rear wheels and the axle are rotated together, and the other of the rear wheels is free to the axle. Clutch means that is rotatably attached and that can arbitrarily contact and separate the other rear wheel and the axle is interposed.

In the riding work machine according to the present invention configured as described above, the following operational effects can be obtained.
(1) Since power transmission can be performed only on the main frame, the structure is simpler, lighter and more compact than the conventional articulated type.
(2) The load from the main frame side is the rotation guide surface member or rolling member provided on the main frame → the rolling member or rotation guide surface member provided on the sub frame → steering wheel (rear two wheels). Therefore, unlike the conventional one, a large load is not applied to the joint portion, and the joint portion (rotation fulcrum) only needs to be strong enough to rotate the subframe and the steering wheel in the horizontal plane. It is possible to simplify the structure and to reduce the cost of parts.
(3) The rear two wheels are used as steering wheels, and the sub-frame to which the rear wheel axle is connected is rotatably supported in a horizontal plane with respect to the main frame, and the sub-frame and the steering wheel axle are rotated. The center of motion is offset forward from the center of the axle, so that the minimum turning radius can be made smaller than that of the front wheel steering, and the trailing phenomenon such as rear wheel steering can be suppressed, Particularly, it is suitable for traveling between trees, and mowing work and the like can be performed efficiently, quickly and smoothly.
(4) When the mowing unit is disposed in front of the front wheels and the rear wheels are steered, the turning radius of the mowing unit is reduced, and uncutting is reduced. Further, the visibility from the driver's seat is high, and the mowing operability is particularly excellent.
(5) Since the mowing part is in front, it is not necessary to pass through as in the prior art, which is advantageous for mowing the back of the branches.
(6) Since there is no mowing portion between the front and rear axles and the rear axle is made to swing in the vertical plane, the running performance on the convex land is improved.
(7) The driver's seat is arranged from the front axle to the center of the vehicle, and the engine is arranged at the rearmost part, so that the overall length can be shortened as compared with a conventional riding mower.

Hereinafter, an embodiment of a riding work machine of the present invention will be described with reference to the drawings.
1 to 6 are respectively a front perspective view, a rear perspective view, a plan view, a rear view, a bottom view, and a main body from which an exterior portion is removed showing an embodiment of a riding work machine (riding mower) according to the present invention. It is a front perspective view of a part.

  In the illustrated example of the riding mower 10, front wheels 14 and 14 as drive wheels are disposed at the front of the vehicle body 12, and rear wheels 16 and 16 as steering wheels are disposed at the rear of the vehicle body 12. A mowing unit 15 having three grass cutting blades arranged side by side in front is arranged. A steering handle 17 is disposed at the front center of the vehicle body 12, a driver seat 18 is provided at the center of the vehicle body 12, and various operation members are arranged around the driver seat 18.

  As shown in FIG. 6, the trunk portion of the vehicle body 12 includes a ladder-shaped main frame 20, and an engine 22 is mounted on the rear portion of the main frame 20. As can be understood by referring to FIG. 7 in addition to FIG. 6, the power of the engine 22 is transmitted to a transmission 25 disposed below the front side of the main frame 20 by a two-stage belt pulley type power transmission mechanism 24. The transmission 25 is transmitted to the front wheels 14 and 14 as traveling driving force and to the mowing unit 15 as mowing power.

  Therefore, in the present embodiment, the main frame 20 is provided with a traveling drive system such as the engine 22 and the transmission 25, a work drive system, a driver's seat, an operation system, and the like.

Further, on the lower side of the rear portion of the main frame 20, an inverted half-plate-shaped rotation guide surface member 27 that serves as a rail on which a roller 47 described later rolls is attached and fixed.
Steering for rotating the axle 60 (axle case 62) of the rear wheels 16, 16 in a horizontal plane on the lower surface of the front end side of the rotation guide surface member 27 in accordance with the steering amount (rotation angle) of the steering handle 17. A turning mechanism 30 is provided.

  The steering rotation mechanism 30 includes a mechanism case portion 32, a steering rotation shaft 33 rotatably disposed in a vertical posture within the mechanism case portion 32, and a rotation posture close to and parallel to the rotation shaft 33. The rotation center shaft 36, the stepped rotation cylindrical shaft 37 that is rotatably fitted to the rotation center shaft 36, and the subframe 40 are provided.

  A sprocket wheel 34b around which a winding transmission chain 34a for rotating the steering rotation shaft 33 is rotated according to the steering amount (rotation angle) of the steering handle 17 is keyed on the upper portion of the steering rotation shaft 33. It is fixedly attached so as to be integrally rotatable by spline coupling or the like. A gear portion 35 for rotating the sub-frame 40 in a horizontal plane is provided at the central portion of the steering rotation shaft 33.

  On the other hand, the rotation center shaft 36 is placed on the bottom plate 32a of the mechanism case portion 32, and sleeves 38 and 39 are fitted on the outer periphery of the upper and lower end portions thereof, and the rotation rotary cylinder shaft 37 and the upper sleeve 38 are fitted. A thrust bearing 41 is interposed therebetween. On the large-diameter stepped portion 37a of the rotating rotary cylinder shaft 37, a cam plate 43 having a generally fan shape (ginkgo leaf shape) in plan view, as can be understood by referring to FIGS. 8 and 9 in addition to FIG. It is fitted and fixed so that it can rotate integrally by press fitting, welding, keying, spline coupling, and the like. A gear portion 45 that meshes with the gear portion 35 is provided over a predetermined angle range on the front side of the cam plate 43 (on the steering rotation shaft 33 side).

  The front portion of the sub-frame 40 is fitted under the large-diameter step portion 37a of the rotating rotary cylinder shaft 37, and is attached and fixed so as to be integrally rotatable by press fitting, welding, keying, spline coupling, or the like. . The sub-frame 40 has an inverted groove shape in cross section and has a rectangular arm shape in plan view. The rear end of the sub-frame 40 protrudes rearward from the rear end of the main frame 20.

  Rollers 47 and 47 as rolling members that receive a load from the main frame 20 side are attached and fixed by welding or the like in the vicinity of the center of the left and right side surfaces of the subframe 40. The rollers 47 are configured to roll around the lower surface outer peripheral end portion of the rotation guide surface member 27.

  A support plate 48 is fixed to the lower surface near the center of the subframe 40 by welding or the like, and the center pin 50 is bridged between the support plate 48 and the front side plate 48 of the subframe 40. Inserted and fixed in a horizontal position. A swing sleeve 52 is rotatably fitted on the center pin 50, and the swing sleeve 52 and an axle case 62 externally inserted on the axle 60 of the rear wheels 16, 16 are arranged in the front and rear of a triangular shape. The connection plates 63 and 64 are connected and fixed.

  On the other hand, the cam plate 43 and the pressing arm mechanism 70 disposed in the vicinity thereof constitute a steering neutral restoring mechanism. As can be understood with reference to FIG. 9, the pressing arm mechanism 70 includes an arm connection holding member 75 attached and fixed to the main frame 20 (the rotation guide surface member 27), and a neutral position where the steering handle 17 is not operated. The first arm 72 having a pressing bearing portion 73 that is in pressure contact with the center (most projecting portion) of the cam surface (outer peripheral end surface) of the cam plate 43, and the first arm 72 cooperate with the first arm 72. In order to form an L-shaped arm, a second arm 74 coupled to the first arm 72 via the arm coupling holding member 75 so as to rotate integrally therewith, and a first arm 72 (press bearing portion 73). A coil spring 76 is provided for pulling the free end side of the second arm 74 to the side in order to urge the cam plate 43 in the pressing direction. The lateral outer end of the coil spring 76 is locked to the main frame 20 (see FIG. 6).

  By the way, when the front wheels 14 and 14 are drive wheels and the rear wheels 16 and 16 are driven wheels as in the present embodiment, the driven wheels are in the trading direction during forward movement, so that straight running stability is obtained. At the time (reverse), the driven wheel is in the leading direction, so the straight running stability is deteriorated. In particular, when the steering angle (cutting angle) is large, the vehicle body tends to be refracted because a force that pushes the joint portion straight by the driving force works.

  Therefore, in the present embodiment, as shown in FIGS. 10 and 11, the axle 60 and the axle 60 can be freely rotated via bearings 66 and 67 between the right rear wheel 16A and the left rear wheel 16B. A supporting axle case 62 is disposed, and the right rear wheel 16A side is configured such that the axle 60 and the hub 81 are fixed by a pin 83 so that the right rear wheel 16A and the axle 60 rotate integrally, and the left The rear wheel 16B is attached to the axle 60 via a free hub 82 so as to be freely rotatable, and a meshing clutch 90 capable of arbitrarily contacting and separating them is interposed between the left rear wheel 16B and the axle 60. .

  The meshing clutch 90 includes a fixed clutch element 91 on the free hub 82 side and a movable clutch element 92 on the axle 60 side. The fixed clutch element 91 is fixed to the free hub 82, and the movable clutch element 92 is Although it is made to rotate integrally with 60, it can be slid in the axial direction. Here, as shown in FIG. 11, when the fixed clutch element 91 and the movable clutch element 92 are separated from each other, the left rear wheel 16B rotates freely regardless of the rotation of the axle 62 and the right rear wheel 16A. can do. On the other hand, when the movable clutch element 92 is moved in the left direction, it engages with the fixed clutch element 91, and the left rear wheel 16B, the axle 60, and the right rear wheel 16B rotate integrally. The movable clutch element 92 is always urged away from the fixed clutch element by an urging means (not shown).

  As a means for moving the movable clutch element 92 to the left and meshing with the fixed clutch element 91, a pusher 95 is slidably provided on the outer periphery of a bearing retainer 68 that is externally fitted and fixed to the left end portion of the axle case 62. It is fitted. The pusher 95 abuts on a bearing 96 (outer race) attached to the outer periphery of the small diameter portion of the movable clutch element 92 and pushes the movable clutch element 92 leftward through the bearing 96. is there. For the movement of the pusher 95, that is, the contact and separation of the clutch 90, for example, a Bowden cable 100 including an inner cable 101 and an outer tube 102 is used as shown in FIG. That is, the inner cable 101 locking metal fitting 97 is fixed to the outer periphery of the bearing retainer 68, and the outer tube locking metal fitting 98 is fixed to the outer periphery of the pusher 95, and the inner cable 101 is pulled, The outer tube 102 is moved forward relatively to the left. 10, the pusher 95 shown in FIG. 10 pushes the movable clutch element 92 to the left via the bearing 96, the fixed clutch element 91 and the movable clutch element 92 are engaged, and the clutch 90 is fastened. The rear wheel 16B, the axle 60, and the right rear wheel 16A rotate integrally, and no differential is generated between them. Therefore, by setting the clutch 90 in the engaged state in conjunction with the reverse drive, straight running stability and the like can be obtained. When the clutch 90 is engaged, the bearings 86 and 87 disposed between the outer periphery of the left end portion of the axle 60 and the free hub 82 are used to produce a differential between the left and right wheels, and each idles independently. However, when it is desired to appropriately adjust the differential amount, the clutch elements 91 and 92 in the clutch 90 may be of a friction type.

  With this configuration, when the steering handle 17 is operated, the steering amount (rotation angle) is transmitted to the steering rotation shaft 33 via the chain 34a and the sprocket wheel 34b, and the steering rotation shaft 33 is steered. It can be rotated according to the amount. When the steering rotation shaft 33 rotates, the rotation is transmitted to the sub-frame 40 via the gear portion 35 → the gear portion 45 of the cam plate 43 → the rotating rotary cylinder shaft 37, and a roller 47 provided on the sub-frame 40, 47 rolls while being pressed against the lower surface of the rotation guide surface member 27, and the sub-frame 40 rotates about the rotation center shaft 36 as a center (fulcrum) O according to the steering amount. As a result, as shown in FIG. 5B, the axle 60 (axle case 62) of the rear wheels 16, 16 also turns with the subframe 40, and steering is performed.

  In the steering neutral restoring mechanism constituted by the cam plate 43 and the pressing arm mechanism 70, the steering handle 17 is operated from the neutral position, and the cam plate 43, the sub frame 40, and the axles of the rear wheels 16, 16 are operated. When 60 (the axle case 62) is rotated in the steering direction, the cam plate 43, the sub-frame 40, and the axles 60 ( A force acts to return the axle case 62) to the neutral position.

  In the riding mower 10 of the present embodiment configured as described above, power can be transmitted only on the main frame 20, so that the structure is simpler, lighter and more compact than the conventional articulated type. .

  Further, since the load from the main frame 20 side is received by the rotation guide surface member 27 provided on the main frame 20 → the roller 47 provided on the sub frame 40 → the steering wheels (rear two wheels 16 and 16), Unlike a thing, a big load is not applied to a joint part, but joint parts, such as the rotating shaft 33 for a steering and the rotating cylinder shaft 37 for rotation, are the intensity | strength which can rotate the sub-frame 40 and the steering wheels 6 and 16 within a horizontal surface. Therefore, the structure of the joint portion can be simplified and the cost of parts can be reduced.

  The operation does not change even if the roller 47 as the rolling member is provided on the main frame 20 and the rotation guide surface member 27 is provided on the subframe 40, and the operation does not change even if a ball is used as the rolling member. .

  Further, the rear two wheels 16 and 16 are steered wheels, and the subframe 40 to which the axle 60 of the rear wheel 16 is connected is supported so as to be rotatable in a horizontal plane with respect to the main frame 20. Further, the center of rotation of the axle 60 of the rear wheels 16 and 16 is offset forward from the center of the axle 60, so that the minimum turning radius can be made smaller than that of the front wheel steering and the rear wheel steering. Such a bottom-swing phenomenon can also be suppressed. In particular, it is suitable for traveling between trees, and mowing work and the like can be performed efficiently, quickly and smoothly.

  In addition, when the mowing unit is disposed in front of the front wheels and the rear wheels are steered, the turning radius of the mowing unit is reduced, and uncutting is reduced. Further, the visibility from the driver's seat is high, and the mowing operability is particularly excellent.

  In order to confirm such an effect, as shown in FIG. 12, it is actually the same size (vehicle width) as the riding mower 10 of the present embodiment [the present invention machine: FIG. 12 (A)]. Etc.), a conventional riding mower 10 ′ having a structure in which the grass cutting portion 15 ′ is located between the front wheels 14 ′, 14 ′ and the rear wheels 16 ′, 16 ′ by steering the front wheels [conventional machine: FIG. 12 (B)]. The minimum turning radius Ra of the present invention was about 1600 mm, while the minimum turning radius Ra ′ of the conventional machine was about 2000 mm. The residual cutting diameter Da was about 1400 mm, whereas the residual cutting diameter Da ′ during turning of the conventional machine was about 1700 mm, demonstrating the above-described effects.

In addition to the above effects, the mowing part is in front, so there is no need to pass through as in the prior art, which is advantageous for mowing behind the branches.
Further, since there is no mowing portion between the front and rear axles, and the rear axle 60 swings in the vertical plane with the center pin 50 as a center (fulcrum) (see FIG. 4), it runs on a convex land. Sexuality etc. become high.

  Furthermore, since the driver's seat 18 is disposed from the front wheels 14 and 14 to the center of the vehicle body and the engine 22 is disposed at the rearmost portion, the overall length can be shortened compared to a conventional riding mower.

1 is a front perspective view showing an embodiment of a riding work machine according to the present invention. The rear perspective view showing one embodiment of the riding work machine concerning the present invention. The top view which shows one Embodiment of the riding work machine which concerns on this invention. The rear view which shows one Embodiment of the riding work machine which concerns on this invention. The bottom view which shows one Embodiment of the riding work machine which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The front perspective view of the basic | foundation part which removed the exterior part which shows one Embodiment of the riding work machine which concerns on this invention. The partial notch expansion side view which shows the principal part of one Embodiment of the riding work machine which concerns on this invention. The lower perspective view which shows the principal part of one Embodiment of the riding work machine which concerns on this invention. The upper perspective view which shows the principal part of one Embodiment of the riding work machine which concerns on this invention. The notch enlarged view of the rear-wheel currently used by one Embodiment of the riding work machine which concerns on this invention. The notch enlarged view of the left rear wheel used by one Embodiment of the riding work machine which concerns on this invention. The figure used for description of the effect of the riding work machine which concerns on this invention.

Explanation of symbols

10 Riding machine (Riding mower)
12 Car body 14 Front wheel 15 Mowing part 16 Rear wheel 17 Steering handle 18 Driver's seat 20 Main frame 22 Engine 27 Rotation guide surface member 30 Steering rotation mechanism 33 Rotating steering shaft 36 Rotating central shaft 37 Rotating rotating cylindrical shaft 40 Sub Frame 43 Cam plate 47 Roller (rolling member)
50 Center Pin 60 Axle 62 Axle Case 90 Engagement Clutch 91 Fixed Clutch Element 92 Movable Clutch Element 95 Pusher

Claims (6)

Traveling drive system including a prime mover such as an engine, a working drive system, the driver's seat and a main frame operating system is Zaisa distribution, the steering wheel together when it is rotatably supported in a horizontal plane at the bottom of the main frame comprising a subframe axle is integrally rotatably connected to a,
Wherein the main frame and one of said sub-frame is provided with a rolling member receiving a load on the other, the semi-dish-like or inverse half dish shaped pivoting guide surface member to which the rolling member rolls Riding work machine characterized by being provided.   The riding work machine according to claim 1, wherein the front two wheels are driving wheels and the rear two wheels are steering wheels, and the axle of the rear wheels is connected to the subframe so as to be integrally rotatable. .   The riding work machine according to claim 1 or 2, wherein a rotation center of the axle of the sub-frame and the steering wheel is offset in a vehicle longitudinal direction from a center of the axle.   The riding according to any one of claims 1 to 3, wherein the axle of the steered wheel is swingable in a vertical plane around a center pin provided in the subframe. Work machine.   The riding according to any one of claims 1 to 4, wherein the front two wheels are driving wheels and the rear two wheels are steering wheels, and a mowing portion is disposed in front of the front two wheels. Work machine.   The rear two wheels are steered wheels and are driven wheels, one of the rear wheels and the axle rotate together, and the other rear wheel is attached to the axle so as to be freely rotatable. The riding work machine according to any one of claims 1 to 5, wherein clutch means capable of arbitrarily contacting and separating them is interposed between the other of the rear wheels and the axle. .

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