Lawn grass reaping apparatus

Abstract

To provide a lawn grass reaping apparatus which prevents breakage of a reaping part, damage to a tree trunk part and unintended reaping of thin seedlings, etc., and does not repeat opening and closing operations even when a machine body is stopped while the reaping part abuts on an obstacle.SOLUTION: A lawn grass reaping apparatus is characterized in that a reaping part 2 provided on the outside of a traveling vehicle body 1 is constituted so as to be openable and closable by driving means 3; the reaping part 2 includes a contact part 4, and the reaping part 2 is operated in the direction of a closed state H when detecting means 6a detects contact of the contact part 4 with an obstacle; the reaping part 2 is operated in the direction of an open state K when the detecting means 6b detects the release of the contact of the contact part 4 with the obstacle; and control is performed so that the opening and closing operations of the reaping part 2 is stopped when both the detecting means 6a and 6b are in a non-detecting state N.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lawn grass cutting device. [Background technology]

[0002] Conventionally, there has been known a self-propelled brush cutter equipped with an openable sub-cutter unit on the side of the machine body, as disclosed in the following Patent Document 1. This conventional technology is configured to close the sub-cutter unit inward using a contact sensor and an actuator, thereby preventing the sub-cutter unit from being damaged by coming into contact with an obstacle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-315417 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not disclose what to do if the sub-cutter unit comes into contact with an obstacle and stops traveling during the closing operation. In this case, the closing operation causes the sub-cutter unit to disengage from the obstacle, the contact sensor goes into a non-detecting state, and the sub-cutter unit transitions to the opening operation, where it comes into contact with the obstacle again. In other words, there is the problem that the sub-cutter unit repeatedly opens and closes unstably. The present invention has been made in consideration of the above-mentioned problem, and aims to provide a lawn mower that prevents damage to the cutting unit, damage to tree trunks, and unintentional cutting of thin saplings, and that does not repeatedly open and close even if the machine is stopped while the cutting unit comes into contact with an obstacle. [Means for solving the problem]

[0005] In the grass cutting device extending outward from the traveling vehicle body 1, the cutting unit 2 is configured to be able to open and close between an open state K in which it is deployed outward and a closed state H in which it is stored inward by a driving means 3, and a contact part 4 is provided in front of the cutting unit 2 in the open state K, and the contact part 4 is configured to rotate backward when it comes into contact with an obstacle such as a tree J while traveling, and is equipped with a biasing means 5 that returns the contact part 4 to the front when it is released from contact with the obstacle, and a contact state P in which the contact part 4 has rotated backward is detected. The grass cutting device is configured to have a detection means 6a that detects the contact state P when the contact part 4 is in contact with the driving means 3, and a detection means 6b that detects the released state C when the contact part 4 has returned to the front, and when the detection means 6a detects the contact state P, the driving means 3 operates the cutting part 2 in the direction of the closed state H, and when the detection means 6b detects the released state C, the driving means 3 operates the cutting part 2 in the direction of the open state K, and when both the detection means 6a and the detection means 6b are in the non-detection state N, the opening and closing operation of the cutting part 2 is controlled to stop.

[0006] According to the invention described in claim 1, when the detection means 6a detects the contact state P, the drive means 3 controls the cutting unit 2 to move in the direction of the closed state H, so that even if the cutting unit 2 comes into contact with an obstacle, such as a tree J, the trunk is not damaged and damage to the cutting unit 2 can be prevented. In addition, since the contact unit 4 is configured to rotate backward when it comes into contact with an obstacle, the impact force when it comes into contact with an obstacle can be reduced. [Effects of the Invention]

[0007] Furthermore, when the detection means 6b detects the release state C, the drive means 3 controls the movement of the cutting unit 2 in the direction of the open state K, so that when the cutting unit 2 is released from contact with the obstacle, the cutting unit 2 is quickly deployed outward, thereby preventing any grass from being left uncut. In addition, the contact portion 4 is configured to return forward by the biasing means 5, so that the cutting unit 2 can smoothly prepare for contact with the next obstacle.

[0008] Furthermore, if the contact portion 4 comes into contact with an obstacle and the traveling vehicle body 1 is stopped while the reaping portion 2 is moving in the direction of the closed state H, the contact portion 4 is pressed against the obstacle by the biasing means 5, while the reaping portion 2 moves in a direction away from the obstacle, so that the contact portion 4 relatively returns forward and the detection means 6a enters a non-detecting state. However, when both the detection means 6a and the detection means 6b are in the non-detecting state N, the opening and closing operation of the reaping portion 2 is controlled to stop, so the opening and closing operation of the reaping portion 2 stops before the detection means 6b detects it. This prevents the reaping portion 2 from repeating an unsteady opening and closing operation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an overall plan view of a riding brush cutter. [Figure 2] FIG. 2 is an overall plan view showing the transmission configuration of the riding brush cutter. [Figure 3] FIG. [Figure 4] FIG. 10 is a plan view showing a rotation state of the side cutter portion. [Figure 5] FIG. 10 is a plan view showing a rotation state of the side cutter portion. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 4 is a schematic plan view showing the automatic opening and closing configuration of the side cutter unit. [Figure 9] FIG. 10 is a plan view of the side cutter portion showing the damper in an extended and retracted state. [Figure 10] FIG. 10 is a plan view showing the locking mechanism of the side cutter unit. [Figure 11] FIG. 3 is a schematic plan view showing the positional relationship between the traveling vehicle body and the reaping unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described with reference to the drawings. A riding brush mower embodying the present invention has a pair of left and right front wheels 7, 7 and rear wheels 8, 8 at the front and rear of a traveling body 1. A seat 9 for an operator is located in the center of the traveling body 1 between the front wheels 7, 7 and the rear wheels 8, 8. A handlebar 10 for steering the front wheels 7, 7 is located in front of the seat 9, and steps S are formed at the operator's feet. A brake pedal 11 and an accelerator pedal 12, which the operator operates with his or her feet, are located on the steps S on the left and right sides of the handlebar 10. An engine 13 is located behind the seat 9, and the top of the engine 13 is covered by an engine cover 14. The engine 13 is a vertical type with an output shaft 15 protruding downward. Two engine pulleys 15p, one above the other, are attached to the output shaft 15, and drive the engine and the main cutter MC via a V-belt 16a. The driving force is transmitted to an HST (hydraulic continuously variable transmission) 17 by a V-belt wound around an engine pulley 15p and an HST pulley, and is then transmitted to rear wheels 8, 8 via a transmission T to which the HST 17 is integrally attached.

[0011] A large-diameter main cutter MC is provided below the seat 9, a sub-cutter SB with a smaller diameter than the main cutter MC is provided to the left front of the main cutter MC, and a side cutter SC with approximately the same diameter as the sub-cutter SB is provided to the left rear of the sub-cutter SB. Cutting blades 18 are attached to the sub-cutter SB and side cutter SC, and the side cutter unit SU consisting of the sub-cutter SB and side cutter SC can be opened and closed by moving approximately horizontally between an open state K in which it is deployed outward from the traveling body 1, and a closed state H in which it is stored inward along the side of the traveling body 1.

[0012] Next, the power transmission configuration from the engine 13 to the main cutter MC, sub cutter SB, and side cutter SC will be described. The large-diameter main cutter MC is entirely covered by a cutting cover 19 and rotates around a main rotating shaft 20, the sub cutter SB rotates around a sub rotating shaft 21, and the side cutter SC rotates around a side rotating shaft 22. The sub cutter SB and side cutter SC are entirely covered by a cutting cover 23, and two stages of main pulleys 20p and sub pulleys 21p, as well as one stage of side pulley 22p, are attached to the upper parts of the main rotating shaft 20, the sub rotating shaft 21, and the side rotating shaft 22, respectively. A counter shaft 24 is provided on the top surface of the cutting cover 19, diagonally rearward and to the left of the main rotating shaft 20, and two stages of counter pulleys 24p are attached to the counter shaft 24. The driving force of the output shaft 15 of the engine 13 is transmitted from the engine pulley 15p via the V-belt 16a to the main pulley 20p, from the main pulley 20p via the V-belt 16b to the counter pulley 24p, from the counter pulley 24p via the V-belt 16c to the sub-pulley 21p, and from the sub-pulley 21p to the side pulley 22p via the V-belt 16d. These transmissions cause all cutters to rotate clockwise in a plan view. The V-belts 16a and 16b are provided with tension clutch mechanisms 25a and 25b that can turn the power transmission on and off. The tension clutch mechanisms 25a and 25b are configured so that the operator can turn the power transmission on and off by tightening or loosening the V-belts 16a and 16b by operating the main clutch lever 26 or the sub-clutch lever 27 back and forth.

[0013] The side cutter unit SU attached to the cutting cover 19 of the main cutter MC can be raised and lowered integrally with the cutting cover 19 to adjust the grass cutting height. Two pairs of parallel link rods 28a, 28b connect the cutting cover 19 to the traveling body 1 above it, and the main cutter MC and side cutter unit SU can be raised and lowered integrally by moving an elevation rod 29 attached to the parallel link rods 28b up and down, and the cutting height can be adjusted with a cutting height adjustment lever 30 attached to an operating section on the left side of the seat 9. The lifting and lowering drive for this cutting height adjustment can be performed by means of a manual lever, actuator, motor, etc.

[0014] The side cutter unit SU can be raised and lowered around a swing shaft 31 in the front-to-rear direction to mow the grass while adjusting the cutting surfaces of the sub cutter SB and side cutter SC to match the slope or undulations of the ground. Above the sub cutter SB, a motor 33 and a gearbox G that reduces the drive of the motor 33 are attached to a rotating frame 32 provided on the top of the cutting cover 23, and an opening / closing arm 35 that rotates together with the output shaft 34 is provided on the output shaft 34 of the gearbox G. The opening / closing arm 35 and the tip of the side cutter unit SU are connected by a damper D, and the driving force of the motor 33 is transmitted via the gearbox G to rotate the opening / closing arm 35 forward and backward, thereby rotating the side cutter unit SU about the sub-rotating shaft 21 and opening and closing between an open position K and a closed position H.

[0015] In front of the side cutter SC in the open position K, a bumper 36b is provided along the front edge Sf of the cutting cover 23, and a pair of parallel link arms 36h, 36h are provided behind the bumper 36b. A spring 37 is provided to bias the bumper 36b so that it rotates forward. If an obstacle such as a tree J strikes the bumper 36b from the front during forward mowing, the bumper 36b moves approximately horizontally backward against the biasing force of the spring 37. One end of the spring 37 is hooked to a biasing arm 38a that rotates together with the parallel link arm 36h at the tip of the side cutter unit SU, and the other end of the spring 37 is hooked to a threaded rod 40 attached to a stay 39 provided on the top surface of the cutting cover 23. The tension of the spring 37 can be adjusted by changing the position of the threaded rod 40 with a nut 41.

[0016] A leaf spring 42h is attached to the middle portion of the urging arm 38a, and a leaf spring 42k is attached to the tip portion of the urging arm 38b. When the bumper 36b moves approximately horizontally rearward, the urging arms 38a and 38b rotate, causing the leaf spring 42k to disengage from the switch 43k and turn it OFF. When the leaf spring 42h then activates the switch 43h to turn it ON, the motor 33 rotates in the reverse direction and rotates the side cutter unit SU around the sub-rotation shaft 21 toward the closed state H. When an obstacle such as a tree J is removed from the bumper 36b, the urging force (tension) of the spring 37 rotates the bumper 36b approximately horizontally forward, and the leaf spring 42h disengages from the switch 43h and turns it OFF. When the leaf spring 42k then activates the switch 43k to turn it ON, the motor 33 rotates forward and rotates the side cutter unit SU toward the open state K. Reference numeral 44 denotes a rotation stopper against which the biasing arm 38a abuts before the bumper 36b abuts against an obstacle such as a tree J, and against which the parallel link arm 36h abuts when the bumper 36b moves substantially horizontally rearward.

[0017] 6, a non-detection state N in which neither switch 43h nor switch 43k is activated is provided between a state in which bumper 36b comes into contact with an obstacle such as a tree J and moves rearward, causing leaf spring 42h to activate switch 43h, and a state in which bumper 36b is released from contact with an obstacle such as a tree J and moves forward, causing leaf spring 42k to activate switch 43k. In the non-detection state N, motor 33 is stopped, thereby controlling side cutter unit SU to stop opening and closing.

[0018] As shown in Figure 10, a lock mechanism L is provided that allows the opening / closing arm 35 to be fixed in rotation or freely rotated. The pin of this lock mechanism L can be inserted and removed from a lock hole 45 to switch the opening / closing arm 35 between a fixed rotation state and a freely rotating state. When the operator grips a lock release lever 46, the pin of the lock mechanism L is removed from the lock hole 45 of the opening / closing arm 35 via a wire 47, placing the side cutter unit SU in a freely rotating state. In this state, by holding the lock fixing lever 48 of the lock release lever 46 in the unlocked state, the side cutter unit SU can be opened or closed by driving the motor 33. The lock mechanism L fixes the rotation of the side cutter unit SU in an open state K, a closed state H, or an intermediate position. When the side cutter unit SU is fixed in the open state K or an intermediate position, the damper D expands and contracts to open or close the side cutter unit SU when an obstacle such as a tree J hits the side cutter unit SU from in front of it. When the side cutter unit SU is fixed in the closed state H position, even if the side cutter unit SU swings due to vibrations during travel or the like, the side cutter unit SU will not gradually rotate in the opening direction, and the side cutter unit SU can be securely held in the closed state H position, without putting a strain on the gears and shafts of the drive system that open and close the side cutter unit SU.

[0019] The operating section on the left side of the seat 9 is provided with a changeover switch 49 which can be switched between an automatic opening / closing mode AM in which the side cutter unit SU can be opened and closed automatically, and a manual opening / closing mode MM in which the side cutter unit SU can be opened and closed manually, and a manual opening / closing switch 50 which allows the operator to electrically open and close the side cutter SC in the manual opening / closing mode MM.

[0020] Next, the automatic opening / closing rotation of the side cutter unit SU will be described. As shown in FIG. 5, first, the lock release lever 46 is gripped to set the lock mechanism L to a freely rotating state. When a tree J abuts against the bumper 36b provided in front of the side cutter unit SU in the open position K while traveling forward, the bumper 36b moves approximately horizontally rearward against the biasing force (tension) of the spring 37. This causes the biasing arms 38a and 38b to rotate, disengaging the leaf spring 42k attached to the biasing arm 38b from the switch 43k and turning it OFF. Next, the leaf spring 42h attached to the biasing arm 38a activates the switch 43h, turning it ON. This causes the motor 33 to rotate in the reverse direction, rotating the opening / closing arm 35 via the gearbox G. The side cutter unit SU, connected via the damper D, moves in the closing direction and rotates to the intermediate position K1. Further forward movement of the traveling vehicle body 1 from this state causes the side cutter unit SU to further close and rotate to the intermediate position K2. If the traveling vehicle body 1 is moved further forward from this state, the bumper 36b is released from contact with the tree J, and the bumper 36b moves substantially horizontally forward due to the biasing force of the spring 37, while the leaf spring 42h disengages from the switch 43h and turns OFF. The leaf spring 42k then activates the switch 43k to turn ON, causing the motor 33 to rotate forward and rotate the side cutter unit SU in the opening direction. If the switch 43h is turned OFF and then the switch 43k is turned ON while the side cutter unit SU is rotating in the closing direction with the switch 43h turned ON, that is, while the motor 33 is rotating in the reverse direction, the rotation direction of the motor 33 changes to forward rotation, causing the side cutter unit SU to rotate in the opening direction.

[0021] When a tree J abuts against the bumper 36b provided in front of the side cutter unit SU and the switch 43h is turned ON, the traveling vehicle 1 is stopped while the side cutter unit SU is rotating in the closing direction. As the side cutter unit SU rotates, it moves away from the tree J. However, because the bumper 36b is pressed against the tree J by the biasing force of the spring 37, the bumper 36b moves forward relatively, and the leaf spring 42h disengages from the switch 43h and turns OFF. This results in the non-detection state N, and the side cutter unit SU stops rotating. When the traveling vehicle 1 is moved forward or backward from this state, the switch 43h or switch 43k turns ON as the bumper 36b moves, and the motor 33 rotates forward or backward, causing the side cutter unit SU to begin opening or closing.

[0022] Figure 8 shows a configuration in which the limit arm 51 is rotated and the motor 33 is rotated forward, reverse, and stopped by turning two limit switches ON and OFF. When the changeover switch 49 is in the automatic opening / closing mode AM and the side cutter unit SU is in the open position K, the limit arm 51 turns the open limit switch 52k ON. In this state, if an obstacle such as a tree J comes into contact with the bumper 36b and the bumper 36b moves backward, the switch 43h turns ON, the motor 33 rotates in the reverse direction, rotating the opening / closing arm 35 and the limit arm 51. When the side cutter unit SU is in the closed position H, the close limit switch 52h turns ON and the rotation of the motor 33 stops. Next, when the bumper 36b is released from contact with an obstacle such as a tree J and moves forward, the switch 43k turns ON, the motor 33 rotates forward, rotating the opening / closing arm 35 and the limit arm 51, and when the side cutter unit SU reaches the open state K, the open limit switch 52k turns ON, and the rotation of the motor 33 stops.

[0023] When the traveling vehicle body 1 is traveling forward and an obstacle abuts the side cutter unit SU, if the speed at which the obstacle rotates the side cutter unit SU in the closing direction is faster than the speed at which the side cutter unit SU is rotated in the closing direction by the drive of the motor 33, the force of the obstacle attempting to close the side cutter unit SU is absorbed by the contracting action of the damper D. Also, if the speed at which the obstacle rotates the side cutter unit SU in the closing direction is slower than the speed at which the side cutter unit SU is rotated in the closing direction by the drive of the motor 33, the switch 43h repeatedly turns ON and OFF as the bumper 36b moves, so the side cutter unit SU gradually closes while repeatedly rotating and stopping. When the bumper 36b is completely released from its abutment with the obstacle, the bumper 36b moves forward, the switch 43h turns OFF, and then the switch 43k turns ON, causing the side cutter unit SU to rotate in the opening direction to the open position K.

[0024] The side cutter unit SU can also be opened or closed by the operator operating the manual open / close switch 50. When the selector switch 49 is set to the manual open / close mode MM and the manual open / close switch 50 is tilted left or right from the center position, the motor 33 rotates and the side cutter unit SU can be opened or closed manually. In this embodiment, when the side cutter unit SU is in the open state K, the open limit switch 52k is ON. If the manual open / close switch 50 is tilted to the right in this state, the motor 33 rotates in the reverse direction and the side cutter unit SU can be rotated in the direction of the closed state H. If the manual open / close switch 50 is kept tilted to the right, the closed state H is reached, the close limit switch 52h is turned ON, and the rotation of the motor 33 stops. Conversely, when the side cutter unit SU is in the closed state H, if the manual open / close switch 50 is turned to the left, the motor 33 will rotate in the forward direction, and the side cutter unit SU will be rotated in the direction of the open state K. If the manual open / close switch 50 is kept turned to the left, the side cutter unit will enter the open state K, the open limit switch 52k will be turned ON, and the rotation of the motor 33 will stop. Furthermore, if the manual open / close switch 50 is released or the manual open / close switch 50 is returned to the center position, the driving of the motor 33 will stop at that position even if the side cutter unit SU is in the middle of rotating to open or close, and if the manual open / close switch 50 is turned to the right or left, the side cutter unit SU can be opened or closed manually again.

[0025] In addition to the above-described embodiment, the present invention may be configured as follows. In the above-described embodiment, the side cutter unit SU, which corresponds to the cutting unit 2, is provided on the left side of the traveling body 1, near the center between the front and rear. However, the installation position of the cutting unit 2 may be on the right side, or diagonally forward or diagonally rearward of the traveling body 1 as shown in FIG. 11 , and is not particularly limited as long as it does not interfere with the cutting transmission or opening / closing rotation of the cutting unit 2. Furthermore, in addition to the above-described embodiment, a motor may be provided in the cutting unit 2 to transmit the cutting power. In addition, the drive means 3 for opening and closing the cutting unit 2 may be selected from a motor, a cylinder, or the like, depending on the installation position and configuration of the cutting unit 2. Furthermore, a plurality of cutting units 2 may be provided on a single traveling body 1.

[0026] In the above embodiment, the side cutter unit SU is configured to be rotatable about the sub-rotation shaft 21 of the sub-cutter SB, thereby enabling the side cutter unit SU to be opened and closed, but the configuration for opening and closing the reaping section 2 is not limited to this. For example, the reaping section 2 may be divided, with one part not operating to open and close, and the other part operating to open and close.

[0027] The reaping method is not limited to the rotary type as in the above embodiment, but may be a hammer knife type. Furthermore, the configuration of the reaping unit 2 is not limited to the side cutter unit SU as in the above embodiment, but may be in the form of an attachment that can be attached to a traveling vehicle such as a tractor. Furthermore, the traveling method of the traveling vehicle 1 is not limited to wheels, but may be crawlers, for example.

[0028] The contact portion 4 may be installed in front of the cutting unit 2 in the outwardly deployed open state K, and the installation position and range in the left-right direction are not limited. For example, the contact portion 4 may be installed across the entire left-right width of the cutting unit 2, or may be installed from approximately the center of the left-right width to the end. Also, multiple contact portions 4 may be installed for one cutting unit 2. The configuration of the contact portion 4 is not limited to the parallel link configuration in the above embodiment, but if a parallel link is used, the bumper 36b can be rotated rearward with the same amount of force even if the position or angle at which an obstacle such as a tree J hits the bumper 36b changes.

[0029] In the above embodiment, the output shaft of the motor 33 and the output shaft 34 of the gearbox G are disposed at approximately the same position in a plan view, but the positions of the output shaft of the motor 33 and the output shaft of the gearbox G may be disposed at different positions in a plan view, and further, the output shaft of the motor 33 may directly rotate the opening / closing arm 35 without going through the gearbox G. The driving means 3 is not limited to the motor 33, and may be, for example, a hydraulic cylinder or an air cylinder. In addition, the installation position of the driving means 3 is not limited to above the reaping unit 2, and may be provided on the traveling body 1, for example. [Explanation of symbols]

[0030] 1 Running vehicle 2 Reaping section 3. Driving means 4 Contact area 5. Actuation means 6b Detection Methods 6h Detection Method C open state H Closed J Tree K Open state N Non-detection state P Contact status

Claims

[Claim 1] In this grass cutting device, which extends outward from the traveling vehicle body (1), the cutting section (2) is configured to be able to open and close by a drive means (3) between an open state (K) in which it is deployed outward and a closed state (H) in which it is stored inward. A contact part (4) is provided in front of the cutting section (2) in the open state (K), and the contact part (4) is configured to rotate backward when it comes into contact with an obstacle such as a tree (J) while traveling. A biasing means (5) is provided to return the contact part (4) to the front when the contact with the obstacle is released, and the contact state (P) in which the contact part (4) has rotated backward is detected. The lawn grass cutting device is provided with a detection means (6a) and a detection means (6b) for detecting a released state (C) in which the contact part (4) has returned to the front, and when the detection means (6a) detects the contact state (P), the driving means (3) operates the cutting part (2) in the direction of a closed state (H), and when the detection means (6b) detects the released state (C), the driving means (3) operates the cutting part (2) in the direction of an open state (K), and when both the detection means (6a) and the detection means (6b) are in a non-detection state (N), the opening and closing operation of the cutting part (2) is controlled to stop.

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