mower

Abstract

To provide a self-traveling sulky mower that includes a side cutter that does not damage stems of trees and reap thin nursery plants, and smoothly opens / closes the side cutter.SOLUTION: A self-traveling sulky mower comprises: a motor 4, an opening / closing arm 5 that rotates via driving of the motor 4, and a damper D connecting the opening / closing arm 5 with the tip of a side cutter SC above a sub cutter SB; a bumper 7b ahead of the side cutter SC in an open state K; a pair of parallel link arms 7h, 7h behind the bumper 7b, configured such that the bumper 7b moves backward almost horizontally when an obstacle such as a tree J hits the bumper 7b; energization means 8 for energizing the bumper 7b to rotate forward; and detection means 9 for detecting movement of the bumper 7b. The side cutter SC is configured as to be automatically openable and closable by normally and reversely rotating the opening / closing arm 5 in accordance with the detection state of the detection means 9.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a self-propelled riding lawn mower for mowing weeds in orchards, fallow fields, etc., and more particularly to an opening and closing configuration of a side cutter in the operation of mowing grass around trees.

Background Art

[0002] When mowing the grass around trees, a self-propelled riding lawn mower provided with a sub-cutter or a side cutter protruding laterally from the vehicle body abdomen is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, when mowing the grass around trees, a configuration is known in which a side cutter is brought into contact with the trunk of a tree, and the side cutter is rotated backward against the biasing force of a damper (such as a spring cylinder), and mowing is performed while rubbing the contact portion against the trunk of the tree. However, when the biasing force of the damper is strong, there is a problem that the side cutter may damage the tree, or when the side cutter comes into contact with a thin seedling or the like, the side cutter may mow without rotating backward to avoid contact. Also, when the biasing force of the damper is weak, there is an inconvenience that the side cutter rotates backward due to the resistance of the grass that needs to be mowed. An object of the present invention is to provide a self-propelled riding lawn mower provided with a side cutter that can smoothly open and close the side cutter, does not damage the trunk of a tree, and can reduce the amount of thin seedlings being mowed.

Means for Solving the Problems

[0005] A self-propelled riding lawn mower is provided with a pair of left and right front wheels 2, 2 and rear wheels 3, 3 at the front and rear of the vehicle body 1, and a main cutter MC and a sub-cutter SB are provided at the front and rear intermediate portion between the front wheels 2, 2 and the rear wheels 3, 3. A side cutter SC that can be opened and closed toward the side of the vehicle body 1 is provided around the sub-cutter SB. Above the sub-cutter SB, a motor 4, an opening and closing arm 5 that rotates by driving the motor 4, and a damper D that connects the opening and closing arm 5 and the tip of the side cutter SC are provided. At the front portion of the side cutter SC in the open state K, a bumper 7b in front of the side cutter SC and along the front edge Sf of the side cutter SC, and a pair of parallel link arms 7h, 7h configured such that when an obstacle such as a tree J contacts the bumper 7b, the bumper 7b moves substantially horizontally rearward, an urging means 8 that urges the bumper 7b to rotate forward, and a detection means 9 that detects the movement of the bumper 7b are provided. The opening and closing arm 5 is rotated forward and backward according to the detection state of the detection means 9, and the side cutter SC is configured to be automatically opened and closed.

[0006] Further, for opening and closing the side cutter SC, a changeover switch 10 that can be switched between an automatic opening and closing mode AM and a manual opening and closing mode MM, and a manual opening and closing switch 11 that allows an operator to electrically open and close the side cutter SC in the manual opening and closing mode MM are provided.

Advantages of the Invention

[0007] In the invention according to claim 1, since a motor 4, an opening and closing arm 5 that rotates by driving the motor 4, and a damper D that connects the opening and closing arm 5 and the tip of the side cutter SC are provided above the sub-cutter SB, when the front portion of the side cutter SC contacts an obstacle such as a tree J during grass cutting operation at high speed, the damper D contracts and the side cutter SC rotates rearward, so that damage to the side cutter SC can be avoided and the impact force when contacting the tree can also be reduced.

[0008] Further, at the front part of the side cutter SC in the open state K, a bumper 7b in front of the side cutter SC and along the front edge Sf of the side cutter SC, and on the rear side of the bumper 7b, a pair of parallel link arms 7h, 7h configured such that when an obstacle such as a tree J contacts the bumper 7b, the bumper 7b moves substantially horizontally backward, biasing means 8 for biasing the bumper 7b to rotate forward, and detection means 9 for detecting the movement of the bumper 7b are provided. Since the opening and closing arm 5 is configured to rotate forward and backward according to the detection state of the detection means 9 and the side cutter SC can be automatically opened and closed, no matter which part of the bumper 7b the trunk of the tree J contacts, the detection means 9 can be detected with the same stroke of substantially the same pressing force, the opening and closing operation of the side cutter SC can be performed smoothly and accurately, and the horizontal movement load of the bumper 7b can be easily adjusted by adjusting the tensile load of the biasing means 8.

[0009] Furthermore, even if a large load that expands and contracts the damper 7b is not applied to the side cutter SC portion, the side cutter SC rotates backward by the driving force of the motor 4. Therefore, even if the bumper 7b contacts the tree J, the side cutter SC can be rotated backward to avoid it without damaging the tree J. By adjusting the biasing means 8 to increase the sensitivity of the horizontal movement of the bumper 7b, the inconvenience of inadvertently cutting immature seedlings and the like can be reduced.

[0010] According to the invention described in claim 2, for opening and closing the side cutter SC, a changeover switch 10 that can be switched between an automatic opening and closing mode AM and a manual opening and closing mode MM, and a manual opening and closing switch 11 that enables an operator to electrically open and close the side cutter SC in the manual opening and closing mode MM are provided. Therefore, according to the thickness of the tree, the type of mowing grass, and the density, the automatic opening and closing and manual opening and closing operations of the side cutter SC can be selected. Even when mowing grass around thin seedlings where the bumper 7b does not move or when it is not desired to bring the side cutter SC into contact with the tree J or seedlings, the side cutter SC can be electrically opened and closed by operating the manual opening and closing switch 11, and inadvertently cutting thin seedlings can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0012] Next, embodiments of the present invention will be described with reference to the drawings. The lawn mower of the present invention is provided with a pair of left and right front wheels 2, 2 and rear wheels 3, 3 before and after the vehicle body 1. A seat 15 on which the operator sits is provided at the center of the vehicle body 1 between the front wheels 2, 2 and the rear wheels 3, 3. A handle 16 capable of steering the front wheels 2, 2 is provided in front of the seat 15, and a step P is formed at the feet. A brake pedal 46 and an accelerator pedal 47 that the operator operates with the feet are provided on the step P on the left and right sides of the handle 16. An engine 17 is arranged behind the seat 15, and the upper part of the engine 17 is covered with an engine cover 18. The engine 17 is of a vertical type with an output shaft 19 protruding downward, and the upper and lower two-stage engine pulleys 19p attached to the output shaft 19 drive the traveling and the main cutter MC via a V-belt. The traveling drive is transmitted to the HST (hydrostatic continuously variable transmission) 22 by a V-belt wound around the engine pulley 19p and the HST pulley, and is transmitted to the rear wheels 3, 3 via a transmission T integrally attached to the HST 22.

[0013] Below the sheet 15, there is a large-diameter main cutter MC, a sub-cutter SB with a smaller diameter than the main cutter MC in front of the left side of the main cutter MC, and a side cutter SC that can rotate around the sub-rotation axis 26 of the sub-cutter SB. Cutting blades 24 are attached to the side cutter SC and the sub-cutter SB. The side cutter unit SU composed of the sub-cutter SB and the side cutter SC is configured to be able to open and close the entire side cutter SC by moving substantially horizontally between an open state K protruding to the side of the cutting cover 23 and a closed state H closing along the side of the vehicle body 1.

[0014] Next, the transmission configuration from the engine 17 to the main cutter MC, the sub-cutter SB, and the side cutter SC will be described. The large-diameter main cutter MC is entirely covered by the cutting cover 23 and rotates around the main rotation axis 25. The sub-cutter SB rotates around the sub-rotation axis 26, and the side cutter SC rotates around the side rotation axis 27. Upper and lower two-stage main pulleys 25p, sub-pulleys 26p, and a single-stage side pulley 27p are attached to the upper parts of the main rotation axis 25, the sub-rotation axis 26, and the side rotation axis 27 respectively. A counter shaft 28 is provided on the upper surface of the cutting cover 23 diagonally behind the left side of the main rotation axis 25, and upper and lower two-stage counter pulleys 28p are attached to the counter shaft 28. The drive of the output shaft 19 of the engine 17 is transmitted from the engine pulley 19p to the main pulley 25p via the V-belt 29, from the main pulley 25p to the counter pulley 28p via the V-belt 30, from the counter pulley 28p to the sub-pulley 26p via the V-belt 31, and from the sub-pulley 26p to the side pulley 27p via the V-belt 32. With these transmissions, all the cutters are configured to rotate clockwise in a plan view. Tension clutch mechanisms 33, 34 that can engage and disengage the transmission are provided on the V-belt 29 and the V-belt 30. The tension clutch mechanisms 33, 34 are configured such that the operator can move the main clutch lever 35 or the sub-clutch lever 36 back and forth to tighten or loosen the V-belts 29, 30 and engage or disengage the transmission.

[0015] The side cutter unit SU attached to the cutting cover 23 of the main cutter MC can be lifted and lowered integrally with the cutting cover 23 to adjust the cutting height of the grass. Two pairs of parallel link rods 40 and 41 connect between the cutting cover 23 and the vehicle body 1 above it, and by moving the lifting rod 42 provided on the parallel link rod 41 up and down, the main cutter MC and the side cutter unit SU can be lifted and lowered integrally, and the cutting height can be adjusted by the cutting height adjustment lever 43 on the side of the seat 15. For the lifting drive for this cutting height adjustment, means using a manual lever, actuator, motor, etc. can be used.

[0016] The side cutter unit SU can perform grass cutting work by undulating and swinging around the rocking shaft 44 in the front - rear direction so that the cutting surfaces of the sub - cutter SB and the side cutter SC follow the slope and undulation of the ground. Above the sub - cutter SB of the cutting cover 55 of the side cutter SC, a motor 4 and a gearbox G for reducing the drive of the motor 4 are attached to the rotating frame 50 provided on the cutting cover 55. An opening - closing arm 5 that rotates together with the output shaft 51 is provided on the output shaft 51 of the gearbox G. The opening - closing arm 5 and the tip of the side cutter SC are connected by a damper D. The driving force of the motor 4 rotates the opening - closing arm 5 forward and backward via the gearbox G, thereby rotating the side cutter SC around the sub - rotation shaft 26, and the side cutter SC and the opening - closing arm 5 are configured to be openable and closable between the open state K and the closed state H. Note that although the output shaft of the motor 4 and the output shaft 51 of the gearbox G are arranged at the same position in plan view, they may be arranged at different positions in plan view, and further, the output shaft of the motor 4 may directly rotate the opening - closing arm 5 without passing through the gearbox G.

[0017] In front of the side cutter SC in the open state K, there is a bumper 7b along the front edge Sf of the side cutter SC, and a pair of parallel link arms 7h, 7h are provided on the rear side of the bumper 7b. A spring 52 is provided to urge the bumper 7b to rotate forward. When a tree J, an obstacle, etc. come into contact with the front of the bumper 7b during the forward mowing operation, the bumper 7b moves substantially horizontally backward against the biasing force of the spring 52. One end of the spring 52 is hung on an urging arm 53 that rotates together with the parallel link arm 7h on the tip side of the side cutter SC, and the other end side of the spring 52 is hung on a threaded rod 57 attached to a stay 56 provided on the upper surface of the cutting cover 55 of the side cutter SC. The tension of the spring 52 can be adjusted by changing the position of the threaded rod 57 with a nut 58.

[0018] A leaf spring 54 is attached to the middle part of the urging arm 53. When the bumper 7b rotates backward, the urging arm 53 also rotates. When the leaf spring 54 actuates the switch 60, the motor 4 rotates, and the side cutter SB rotates toward the closed state H around the sub-rotation shaft 26. When the tree J or the obstacle disengages from the bumper 7b, the bumper 7b rotates substantially horizontally forward by the biasing force (tension) of the spring 52, and at the same time, the switch 60 is turned off, and the motor 4 is rotated to rotate the side cutter SC toward the open state K. Reference numeral 59 is a rotation stopper that contacts the urging arm 53 before the bumper 7b contacts the tree J or the like, and the parallel link arm 7h contacts when the bumper 7b moves substantially horizontally backward.

[0019] As shown in Fig. 9, a lock mechanism L is provided that can select between rotationally fixing and freely rotating the opening / closing arm 5. By inserting and removing the pin of this lock mechanism L into and from the lock hole 5a of the opening / closing arm 5, it is possible to switch between the rotationally fixed state and the freely rotating state of the opening / closing arm 5. When the operator grips the unlocking lever 62, the pin of the lock mechanism L is pulled out from the lock hole 5a of the opening / closing arm 5 via the wire 64, and the side cutter SC enters the freely rotating state. By holding the lock fixing lever 63 of the unlocking lever 62 in the unlocked state in this state, the side cutter SC can be opened and closed by driving the motor 4. The lock mechanism L is for fixing the rotation of the side cutter SC in the open state K, the closed state H, or an intermediate position therebetween. When the side cutter SC is fixed in the open state K or the intermediate position, if a tree J or an obstacle contacts the side cutter SC from the front, the side cutter SC opens and closes due to the expansion and contraction of the damper D. When the side cutter SC is fixed in the closed state H position, even if the side cutter SC swings due to running vibrations during movement, the side cutter SC will not gradually rotate in the opening direction, and it is possible to reliably hold the side cutter SC in the closed state H position, without imposing a burden on the gears and shafts of the drive system path from the motor 4 to the side cutter SC.

[0020] On the operation part on the left side of the seat 15, there is a changeover switch 10 that can be switched between an automatic opening / closing mode AM in which the side cutter SC can be automatically opened and closed and a manual opening / closing mode MM in which the side cutter SC can be manually opened and closed, and a manual opening / closing switch 11 that allows the operator to electrically open and close the side cutter SC in the manual opening / closing mode MM.

[0021] Next, the automatic opening and closing rotation of the side cutter SC will be described. As shown in FIG. 5, first, grasp the unlocking lever 62 to put the locking mechanism L in a freely rotatable state. When a tree J or the like contacts the bumper 7b provided on the front side of the side cutter SC in the open state K during forward travel, as the bumper 7b moves substantially horizontally in the direction approaching the side cutter SC (rearward), the biasing arm 53 rotates against the biasing force of the tension spring 52. When the leaf spring 54 attached to the biasing arm 53 turns the switch 60 to the ON state, the motor 4 rotates the opening and closing arm 5 via the gearbox G, and rotates the side cutter SC connected via the damper D to the intermediate position K1. When the vehicle body 1 further moves forward from this state, the side cutter SC further rotates to the intermediate position K2 in the closing direction. When the vehicle body 1 is further advanced from this state, the tree J is released from the contact state with the bumper 7b, and the bumper 7b moves horizontally away from the side cutter SC by the biasing force of the tension spring 52, and the switch 60 is turned off, so that the motor 4 starts rotating and rotates the side cutter SC in the opening direction.

[0022] Fig. 7 shows a configuration in which the limit arm 66 is rotated to turn the motor 4 forward, reverse, and stop by turning on and off two limit switches. When the switching switch 10 is in the automatic opening / closing mode AM and the side cutter SC is in the open state K, the limit arm 66 turns on the open limit switch 67k. In this state, when a tree J or the like abuts on the bumper 7b and the bumper 7b moves rearward, the switch 60 turns on, and the motor 4 rotates reversely to rotate the opening / closing arm 5, and the side cutter SC can be rotated in the closing direction via the damper D. When the obstacle such as the tree J is released from abutting on the bumper 7b and the bumper 7b moves substantially horizontally by the biasing force of the spring 52 and the switch 60 turns off, the motor 4 rotates forward to rotate the opening / closing arm 5, and the side cutter SC can be rotated in the opening direction via the damper D. Therefore, in the automatic opening / closing mode AM, when the switch 60 turns on, the motor 4 rotates reversely to rotate the opening / closing arm 5 and the limit arm 66, and when the closed limit switch 67h turns on, the rotation of the motor 4 stops. Conversely, when the switch 60 turns off, the motor 4 rotates forward to rotate the opening / closing arm 5 and the limit arm 66, and when the open limit switch 67k turns on, the rotation of the motor 4 stops. If the motor 4 is rotating reversely when the side cutter SC is rotating in the closing direction, and the switch 60 turns off in this state, the rotation direction of the motor 4 changes to forward rotation, and it is configured to rotate the side cutter SC in the opening direction.

[0023] When the speed at which the side cutter SC is rotated in the closing direction by the drive of the motor 4 is slower than the speed at which the side cutter SC is rotated in the closing direction when the vehicle body 1 moves forward and the side cutter SC contacts an obstacle such as a tree J, the force attempting to close the side cutter SC is absorbed by the contracting action of the damper D. Also, when the speed at which the side cutter SC is rotated in the closing direction by the drive of the motor 4 is faster than the speed at which the side cutter SC is rotated in the closing direction when the vehicle body 1 moves forward and the side cutter SC contacts an obstacle such as a tree J, depending on the ON or OFF state of the switch 60 as the bumper 7b moves, the motor 4 is rotated forward and backward to rotate the side cutter SC for opening and closing to avoid the tree J. When the bumper 7b is completely released from the contacting state with the tree J, the bumper 7b moves in the direction away from the side cutter SC, the switch 60 becomes the OFF state, the motor 4 is rotated in the direction in which the side cutter SC opens, and the side cutter SC is rotated to the open state K.

[0024] The side cutter SC can also be opened and closed by the operator operating the manual opening and closing switch 11. When the changeover switch 10 is set to the manual opening and closing mode MM and the manual opening and closing switch 11 is tilted from the central position to the left or right, the motor 4 rotates and the side cutter SC can be manually opened and closed. For example, when the side cutter SC is in the open state K, the open limit switch 67k is in the ON state. In this state, if the manual opening and closing switch 11 is tilted to the right, the motor 4 rotates reversely and the side cutter SC can be rotated in the closing direction. If the state where the manual opening and closing switch 11 is tilted to the right is continued, the close limit switch 67h becomes the ON state and the rotation of the motor 4 stops. Conversely, when the side cutter SC is in the closed state H, if the manual opening and closing switch 11 is tilted to the left, the motor 4 rotates forward and the side cutter SC can be rotated in the opening direction. Also, when the hand is released from the manual opening and closing switch 11 or the manual opening and closing switch 11 is returned to the central position, even if the side cutter SC is in the middle of opening and closing rotation, the drive of the motor 4 stops at that position.

[0025] As shown in FIGS. 1 and 2, a caster wheel 70 is provided at the tip of the side cutter SC to prevent the tip of the side cutter SC from hanging down due to its own weight. The caster wheel 70 rotates about the caster shaft 72 of the caster rod 71, the caster rod 71 rotates about the rod shaft 73, an arm 74 is welded to the caster rod 71, and the tip of the arm 74 and the side of the cutting cover 23 (non-rotating side not associated with the opening and closing rotation of the side cutter SC) are connected by a rod 75. With this configuration, when the side cutter SC is rotated from the open state K toward the closed state H, the caster wheel 70 rotates away from the vehicle body 1, and the caster wheel 70 does not contact the vehicle body 1 or the rear wheel 3 even in the fully closed state H of the side cutter SC. Also, when the side cutter SC in the closed state H is rotated toward the open state K, the caster wheel 70 rotates toward the vehicle body 1, and the caster wheel 70 can prevent the side cutter SC from hanging down without protruding laterally beyond the tip of the side cutter SC.

Explanation of Signs

[0026] 1 Vehicle body 2 Front wheel 3 Rear wheel 4 Motor 5 Opening and closing arm 7b Bumper 7h Parallel link arm 8 Biasing means 9 Detection means 10 Switching switch 11 Manual opening and closing switch AM Automatic opening and closing mode D Damper H Closed state J Tree K Open state MC Main cutter MM Manual opening and closing mode SB Sub-cutter SC Side cutter

Claims

1. A self-propelled riding lawn mower having a pair of left and right front wheels (2), (2) and rear wheels (3), (3) provided on the front and rear of a vehicle body (1), a main cutter (MC) and a sub-cutter (SB) provided at a front-rear intermediate portion between the front wheels (2), (2) and the rear wheels (3), (3), and a side cutter (SC) provided around the sub-cutter (SB) and capable of opening and closing toward the side of the vehicle body (1). In the self-propelled riding lawn mower, a motor (4) is provided above the sub-cutter (SB), an opening and closing arm (5) that rotates by driving of the motor (4), and a damper (D) that connects the opening and closing arm (5) and the tip of the side cutter (SC) are provided. At the front portion of the side cutter (SC) in the open state (K), a bumper (7b) in front of the side cutter (SC) and along the front edge (Sf) of the side cutter (SC), and a pair of parallel link arms (7h), (7h) configured such that when an obstacle such as a tree (J) contacts the bumper (7b), the bumper (7b) moves substantially horizontally rearward, an urging means (8) for urging the bumper (7b) to rotate forward, and a detection means (9) for detecting the movement of the bumper (7b) are provided. The opening and closing arm (5) is rotated forward and backward according to the detection state of the detection means (9), and the side cutter (SC) is configured to be automatically opened and closed.

2. The self-propelled riding lawn mower according to claim 1, further comprising a changeover switch (10) capable of switching between an automatic opening and closing mode (AM) and a manual opening and closing mode (MM) for opening and closing the side cutter (SC), and a manual opening and closing switch (11) that enables an operator to electrically open and close the side cutter (SC) in the manual opening and closing mode (MM).

Images