Walk-behind slope mower

Abstract

To provide a mower that has the excellent vehicle body front-rear balance, can perform reciprocating mowing while moving forward and backward, can swing a reaping device from the hand and easily adjust the device to a desired grass mowing height and has the clean mowing track.SOLUTION: Pairs of left and right front wheels 2, 2 and rear wheels 3, 3 are provided at the front and rear of a vehicle body 1. A gearbox G fitted with a prime mover 4 is installed in the middle of the left and right sides of the rear wheels 3, 3. A hammer knife-style reaping device 6 that pivotally supports a reaping blade shaft 5 in the lateral direction is attached to the front part of the gearbox G. The gearbox G, the prime mover 4 and the reaping device 6 are configured to swing in an integrated manner around drive shafts 7, 7 of the rear wheels 3, 3. A swing lever 10 capable of vertically swinging the reaping device 6 is installed on an operation part 9 located at the tip of a handle rod 8 which is extended toward the rear side of the vehicle body 1 and capable of turning and vertically rotating with respect to the vehicle body 1. The mowing height of the grass can be changed by operating the swing lever 10.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a walking type lawn mower capable of vertically swinging a hammer knife type cutting device provided on the lower abdomen of a vehicle body and adjusting the cutting height of grass.

Background Art

[0002] Patent Document 1 describes a lawn mower provided with a cutting device having a horizontally rotating cutting blade in the middle abdomen between the front and rear of the front and rear wheels, and capable of adjusting the cutting height of grass by adjusting the height of the front and rear wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, when a hammer knife type cutting device is provided in a lawn mower, the height of the cutting device itself is higher than that of a rotary knife type having a horizontally rotating cutting blade, and there is a problem that the vehicle height increases when it is provided on the lower abdomen of the vehicle body. In particular, in many small lawn mowers, the cutting device is provided in front of the vehicle body. When a heavy cutting device is provided in front of the vehicle body, reciprocating cutting while moving forward and backward cannot be performed, and there is also a problem that the front-rear weight balance deteriorates. The hammer knife type has the merit that the cut grass is finely pulverized while being cut, so that post-treatment of the cut grass is unnecessary and the cut mark is clean. However, due to the cutting resistance, the cutting device is likely to float upward, and it is necessary to make the structure such that the cutting device is difficult to float upward in order to maintain a clean cut mark. An object of the present invention is to provide a lawn mower having a good front-rear balance of the vehicle body, capable of reciprocating cutting while moving forward and backward, capable of swinging the cutting device from hand, easily adjusting to an arbitrary cutting height of grass, and having a clean cut mark.

Means for Solving the Problems

[0005] The vehicle body 1 is equipped with a pair of front wheels 2,2 and rear wheels 3,3 on the left and right sides. A gearbox G to which a prime mover 4 is attached is provided in the middle of the left and right rear wheels 3,3. A hammer knife type mowing device 6, which pivots a lateral cutting blade shaft 5, is attached to the front of the gearbox G, in the middle of the front and rear between the front wheels 2,2 and the rear wheels 3,3. The gearbox G, prime mover 4, and mowing device 6 are configured to swing integrally around the drive shafts 7,7 of the rear wheels 3,3. An operating section 9 is provided at the tip of a handle rod 8 that extends toward the rear of the vehicle body 1 and is capable of swiveling and vertically rotating relative to the vehicle body 1. A swing lever 10 is provided on the tip of the handle rod 9, which is capable of swinging the mowing device 6 up and down. The mowing height can be changed by operating the swing lever 10.

[0006] Furthermore, the vehicle body 1 is provided with a swing-and-lock mechanism 11 that allows the harvesting device 6 to be swung and locked, and unlocked. The swing lever 10 of the operating unit 9 and the swing-and-lock mechanism 11 are connected by a fixing cable 12 and a swing cable 13. When the handle rod 8 is located at the rear of the vehicle body 1, the operator behind the operating unit 9 can operate the swing lever 10 in the left-right direction to swing and lock the harvesting device 6 via the fixing cable 12. By operating the swing lever 10 in the front-back direction, the harvesting device 6 can be swung up and down via the swing cable 13, allowing the cutting height to be adjusted. [Effects of the Invention]

[0007] The invention described in claim 1 is provided with a pair of front wheels 2,2 and rear wheels 3,3 on the front and rear of the vehicle body 1, a gearbox G to which a prime mover 4 is attached is provided in the middle of the left and right rear wheels 3,3, and a hammer knife type mowing device 6 with a lateral cutting blade shaft 5 pivotally attached to the front of the gearbox G in the middle of the front and rear between the front wheels 2,2 and the rear wheels 3,3, so that the front and rear balance of the vehicle body 1 is good and reciprocating mowing is possible while moving forward and backward. Furthermore, since the gearbox G, prime mover 4 and mowing device 6 are configured to swing integrally around the drive shafts 7,7 of the rear wheels 3,3, the weight of the gearbox G and prime mover 4 is applied in a direction that causes the mowing device 6 to swing downward (towards the ground), so that the mowing device 6 is not easily lifted by the recoil of mowing, and stable driving and mowing work with a clean cut are possible. Furthermore, a swing lever 10 is provided at the tip of a handle rod 8 that extends toward the rear of the vehicle body 1 and is capable of swiveling and vertically rotating relative to the vehicle body 1. This swing lever 10 allows the mowing device 6 to be operated up and down, and the mowing height can be changed by operating the swing lever 10. As a result, the operator can easily adjust the mowing height to any desired level by swinging the mowing device 6 up and down from their hand.

[0008] The invention described in claim 2 is provided with a swing-fixing mechanism 11 on the vehicle body 1 that allows the swing-fixing and release of the mowing device 6. Therefore, when the up-and-down swinging of the mowing device 6 is fixed to the vehicle body 1, the mowing device 6 will not easily lift up due to the resistance of grass cutting, and a clean mowing pattern can be maintained. Furthermore, the swing lever 10 of the operating unit 9 and the swing-fixing mechanism 11 are connected by a fixing cable 12 and a swing cable 13. When the handle rod 8 is located at the rear of the vehicle body 1, the operator behind the operating unit 9 can operate the swing lever 10 in the left-right direction to enable the swing-fixing and release of the mowing device 6 via the fixing cable 12. By operating the swing lever 10 in the front-back direction, the mowing device 6 can be swung up and down via the swing cable 13 to adjust the cutting height. Therefore, by operating a single swing lever 10 at hand, the operator can easily change and adjust the grass cutting height to any height, and the up-and-down swinging of the mowing device 6 relative to the vehicle body 1 can be fixed. [Brief explanation of the drawing]

[0009] [Figure 1] Overall side view. [Figure 2] Overall floor plan. [Figure 3] A side view and a partial top view showing the oscillating operation of the harvesting device. [Figure 4] A side view showing the oscillating operation of the harvesting device. [Figure 5] A partial cross-sectional view showing the vehicle body. [Figure 6] A side view showing the transmission section of the harvesting device. [Figure 7] A partial cross-sectional plan view showing the arrangement of the torque limiter. [Figure 8] A partial cross-sectional view showing the transmission case and harvesting device. [Figure 9] Cross-sectional view of the torque limiter. [Figure 10] A side view showing the lawnmower in an upright position. [Figure 11] Side view showing the handle extension and retraction. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described with reference to the drawings. The lawnmower of the present invention has a pair of front wheels 2,2 and rear wheels 3,3 on the front and rear of a vehicle body 1, the front wheels 2,2 are connected by a front wheel drive shaft 14, a gearbox G with a prime mover 4 mounted on top is provided in the middle of the left and right rear wheels 3,3, and the rear wheels 3,3 are attached to the drive shafts 7,7 of the gearbox G. The prime mover 4 is attached to the upper side of the gearbox G, and the driving force of the prime mover 4 drives all the wheels of the front wheels 2,2 and rear wheels 3,3 via a transmission unit 18, making it a four-wheel drive lawnmower. A fuel tank 47 is located in front of the prime mover 4, a muffler M is provided on the right side, and exhaust gas is discharged J from the exhaust port 65 toward the left side of the vehicle body 1. The fuel tank 47 located in front of the prime mover 4 is formed in a plan view in an L shape with the right side bent toward the rear, and a fuel filler port 60 is provided above the bent part, with a cap 60a attached.

[0011] A hammer-knife type cutting device 6 is provided on the front side of the gearbox G, pivoting a lateral cutting blade shaft 5. These cutting devices 6, the gearbox G, and the prime mover 4 are configured to swing integrally around the drive shafts 7, 7. The left side of the vehicle body 1 between the drive shaft 7 and the front wheel drive shaft 14 is connected by a gate-shaped frame pipe 17 when viewed from the side, and the right side is connected by a gate-shaped transmission case 16 when viewed from the side, which has a chain 15 inside. A connecting base 20 is provided in front of the prime mover 4, connecting the frame pipe 17 and the transmission case 16 from left to right. A handle base 21 is erected upward from the center of the connecting base 20, and a handle rod 8 is provided at the upper end of the handle base 21, extending upward towards the rear of the vehicle body 1. As shown in Figures 1 and 2, the handlebar rod 8 can rotate up and down at appropriate angles, and can also swivel approximately 120 degrees to the left and right (240 degrees total) from the rearward-facing side of the vehicle body 1 in a plan view. Furthermore, as shown in Figure 11, its length can be adjusted by extending and retracting, allowing the handlebar rod 8 to be adjusted to any position and length according to the usage conditions. The extension and retraction mechanism of the handlebar rod 8 involves inserting the inner pipe 8u into the outer pipe 8s welded to the upper end of the handlebar base 21, and extending and retracting by sliding the inner pipe 8u within the outer pipe 8s. V is a handlebar lock mechanism; when the lock is released, the inner pipe 8u can extend and retract, and when locked, the sliding of the inner pipe 8u is fixed.

[0012] The inner pipe 8u of the handlebar 8 is configured to protrude forward from the front end of the outer pipe 8s when the handlebar 8 is retracted to its shortest length, allowing the vehicle body 1 to stand upright as shown in Figure 10. Note that when the vehicle body 1 is upright with a full tank of fuel, fuel may leak from the cap 60a of the fuel filler port 60 of the fuel tank 47. However, when the vehicle body 1 is upright, the fuel filler port 60 is located at the top of the fuel tank 47, so fuel will not leak if the fuel level E is lower than the fuel filler port 60. The shape of the fuel tank 47 is not limited to the L-shape of this embodiment; any shape in which the fuel filler port 60 is positioned at the upper end of the fuel tank 47 when the vehicle body 1 is upright is acceptable.

[0013] A transmission pulley 23 is attached to the tip of a cutter blade transmission shaft 22 that protrudes from the front of the gearbox G toward the right side. Power is transmitted between the transmission pulley 23 and a cutter blade pulley 24 attached to the right tip of a cutter blade shaft 5 arranged in parallel with the cutter blade transmission shaft 22 by a V-belt 25. As shown in Fig. 6, the V-belt 25 can transmit power from the cutter blade transmission shaft 22 to the cutter blade shaft 5 and cut by rotating a tension pulley 26 provided between the transmission pulley 23 and the cutter blade pulley 24 from the inside of the V-belt 25 to tighten the V-belt 25 outward or loosen it by rotating it inward.

[0014] The cutter blade shaft 5 is pivotally supported by the left and right side plates of a cutter blade cover 27, and a cutter blade K is attached to a plurality of cutter blade bases 28 provided on the cutter blade shaft 5. Scattering covers 38 are provided on the front and rear sides of the cutter blade cover 27 of the cutting device 6 to prevent grass, gravel, etc. from scattering. In the walking-type slope mower of this embodiment, regardless of the front-rear traveling direction, the front side of the rotation area of the cutter blade K is configured to rotate in the upper direction. However, when traveling forward, the front side of the rotation area of the cutter blade K can be rotated in the upper direction, and when traveling backward, the rear side of the rotation area of the cutter blade K can be reversely rotated in the upper direction.

[0015] An operation unit 9 is provided at the tip of a handle rod 8, allowing an operator to change the cutting height, move the handle rod 8 up and down, adjust the turning, adjust the telescopic length of the handle rod 8, switch the forward and backward movement of the travel, change the travel speed, engage and disengage the cutter blade clutch, and operate the accelerator of the prime mover 4 at hand. 29 is a handle lever. When grasped, the up-and-down rotation and turning lock of the handle rod 8 are released via a turning cable 62 and an up-and-down cable 63, enabling the operator to freely adjust the up-and-down height and turning position of the operation unit 9 of the handle rod 8. 30 is a telescopic lever of the handle rod 8. When grasped, the lock of the handle lock mechanism V is released, allowing the handle rod 8 to be telescoped for length adjustment. 31 is a forward-backward switching lever. The center is in the neutral position. When viewed from the rear of the operation unit 9 and operated to the right, the clutch 31k in the gearbox G can be switched to move forward, and when operated to the left, it can be switched to move backward.

[0016] Reference numeral 32 is a shift lever for changing the traveling speed. By operating it in the front-back direction, the change arm 32c in the gearbox G can be switched to high speed or low speed. Reference numeral 33 is a cutter blade clutch lever for engaging and disengaging the transmission to the cutter blade K. By operating this cutter blade clutch lever 33 in the front-back direction, the tension pulley 26 is rotated via the cable 330 and the tension arm 260 to tighten or loosen the V-belt 25, thereby engaging and disengaging the transmission from the cutter blade drive shaft 22 to the cutter blade shaft 5. Reference numeral 34 is the accelerator lever of the prime mover 4. When this accelerator lever 34 is gripped and rotated toward the grip 8g side, the rotational speed of the prime mover 4 increases. When it rises above a predetermined rotational speed, the centrifugal clutch 35 is engaged, and the drive of the prime mover 4 is transmitted to the transmission path in the gearbox G.

[0017] FIG. 3 and FIG. 4 show a mechanism in which the mowing device 6 integrally swings up and down about the drive shaft 7 together with the gearbox G and the prime mover 4. The operation panel 36 of the operation unit 9 forms a sliding guide 37 for sliding the swing lever 10. By sliding and rotating the swing lever 10 back and forth along the sliding guide 37, the mowing device 6 can be swung up and down via the swing cable 13. The sliding guide 37 is formed with a plurality of locking portions 37a for locking the swing lever 10. By locking the swing lever 10 to each of the locking portions 37a, the mowing height of the mowing device 6 can be swung up and down in steps.

[0018] L represents the state where the swing lever 10 is rotated to its furthest forward position, setting the cutting height of the harvesting device 6 to its lowest point, while H represents the state where the swing lever 10 is rotated to its furthest rear position and locked to the locking part 37a, setting the cutting height of the harvesting device 6 to its highest point. The swing lever 10 can rotate forward and backward around the forward and backward swing axis 40, and can also rotate left and right around the release rotation axis 41. Therefore, when the swing lever 10 is rotated from the fixed position Y to the released position X around the release swing shaft 41, the fixed cable 12 is pulled, and the swing fixing mechanism 11 that fixes the harvesting device 6 and the vehicle body 1 is released. In this state, when the swing lever 10 is rotated in the forward and backward direction around the forward and backward swing shaft 40, the harvesting device 6, together with the prime mover 4 and gearbox G, swings up and down around the drive shaft 7 via the swing cable 13. By rotating the swing lever 10 from the released position X to the fixed position Y and to an appropriate locking part 37a and locking it, the swing fixing mechanism 11 fixes the swinging of the harvesting device 6 and the vehicle body 1.

[0019] Furthermore, Figures 3 and 4 show a swing-fixing mechanism 11 in which, when the swing lever 10 is rotated toward the release position X, the engagement between the fixing hole 45 and the fixing pin 42 of the rotating plate 44, which rotates around the pivot axis 43 against the biasing force of the spring 46 via the fixing cable 12, is released, and when the swing lever 10 is returned to the fixed position Y, the fixing hole 45 and the fixing pin 42 engage again. It is sufficient if the up-and-down swing of the harvesting device 6 is fixed relative to the vehicle body 1 after the harvesting device 6 has been adjusted to an arbitrary cutting height.

[0020] Rear wheels 3,3 are provided at the ends of the left and right drive shafts 7, and front wheels 2,2 are provided at the left and right ends of the front wheel drive shaft 14, which is provided parallel to the drive shaft 7. Between the drive shaft 7 and the front wheel drive shaft 14, a gate-shaped transmission case 16 is provided that covers the upper part of the harvesting device 6 in a side view, and the driving system is a four-wheel drive type in which power is transmitted from the right drive shaft 7 to the front wheel drive shaft 14 via a chain 15 inside the transmission case 16. The frame 1a of the vehicle body 1 is composed of a transmission case 16 equipped with a chain 15 that drives the front wheel drive shaft 14 from one of the left and right drive shafts 7,7 of the rear wheels 3,3 of the gearbox G, and a frame pipe 17 on the other side, forming a lattice-shaped frame 1a in a plan view. The transmission case 16 is composed as part of the frame 1a, and there is no need to provide a separate frame member, and together with the frame pipe 17 on the other side it forms a lattice-shaped frame 1a in a plan view, so it is possible to construct a strong and inexpensive vehicle body 1. Furthermore, since the transmission case 16 and the upper part of the frame pipe 17 are connected by the connecting base 20, an even more robust frame 1a can be constructed.

[0021] Each wheel A is provided with a first torque limiter T1 that, if an excessive torque exceeding a predetermined level is applied to the wheel A, cuts off the torque transmission between the wheel A and the drive shaft 7 or the front wheel drive shaft 14. Figure 9 shows the first torque limiter T1 (ball type) of the present invention. The wheel A is pivotally supported on the drive shaft 7 or the front wheel drive shaft 14 via the first torque limiter T1. A spring groove 54 is formed in the drive shaft side boss 51 into which a spring 53 and a steel ball 52 are fitted. The drive shaft side boss 51 is inserted into the drive shaft 7 or the front wheel drive shaft 14 and secured with a C-type retaining ring 55. A ball pocket 50a is provided on the inner circumference of the wheel side flange 50, and the steel ball 52 is fitted into the ball pocket 50a by the biasing force of the spring 53. If excessive torque is applied to the driven wheel A, the engagement of the steel ball 52 with the ball pocket 50a of the wheel-side flange 50 is released, thus preventing excessive torque that could damage the drive shaft 7 and the front wheel drive shaft 14. Furthermore, the drive shaft 7 in the gearbox G is equipped with a friction plate type second torque limiter T2, and when the sum of the torques applied to all wheels A exceeds the set torque of the second torque limiter T2, the second torque limiter T2 is activated, and the transmission to the wheels A is cut off all at once.

[0022] In this embodiment, the operating torque of the first torque limiter T1 is set to 7 kg / m, and the operating torque of the second torque limiter T2 is set to 18 kg / m. That is, the operating torque of the second torque limiter T2 is set higher than the operating torque of the first torque limiter T1 installed on each wheel A, so that when the load applied to each wheel A is less than 7 kg / m, and the sum of the loads applied to each wheel A is 18 kg / m or more, the second torque limiter T2 activates, and the transmission to the wheels A is shut off all at once. If the operating torque of the first torque limiter T1 on each wheel A is 7 kg / m and there is no second torque limiter T2, the maximum torque applied to each wheel A will be less than 7 kg / m, and the sum of the torques applied to the transmission path will be approximately 28 kg / m, so the transmission path in the gearbox G must have sufficient strength to withstand this maximum torque. Furthermore, if the chain 15 inside the transmission case 16 breaks and the sprocket S locks inside the transmission case 16, the excessive output torque from the prime mover 4 is directly applied to the transmission path, causing damage to the transmission path. Also, if the operating torque of the second torque limiter T2 is set to 18 kg / m and there is no first torque limiter T1, once the second torque limiter T2 is activated, the transmission to all wheels A is cut off, making it impossible to drive, resulting in poor off-road capability. Therefore, by providing both the first torque limiter T1 and the second torque limiter T2, both of these problems can be solved. [Explanation of Symbols]

[0023] 1. Vehicle body 2 Front wheels 3 Rear wheels 4. Engine 5 Cutting blade shaft 6 Reaping device 7 Drive shaft 8 handles 9 Control section 10. Swivel lever 11. Swivel-locking mechanism 12 Fixed Cables 13. Oscillating Cable G Gearbox

Claims

1. The vehicle body (1) is equipped with a pair of front wheels (2), (2) and rear wheels (3), (3) on the left and right sides, a gearbox (G) to which a prime mover (4) is attached is mounted in the middle of the left and right rear wheels (3), (3), a hammer knife type cutting device (6) with a lateral cutting blade shaft (5) pivotally attached is mounted in the middle of the front and rear of the gearbox (G) between the front wheels (2), (2) and the rear wheels (3), (3), and these gearbox (G), prime mover (4), and cutting device (6) are connected. A walking-type slope mower characterized in that the rear wheels (3), (3) are configured to swing integrally around the drive shafts (7), (7), and an operating section (9) is provided at the tip of a handle rod (8) that extends toward the rear of the vehicle body (1) and is capable of swiveling and vertically rotating relative to the vehicle body (1), and the mowing device (6) is operated by a swing lever (10) that is provided at the tip of the operating section (9), and the mowing device (6) is operated by swinging the swing lever (10) up and down, thereby changing the mowing height of the grass.

2. The walking-type slope mower according to claim 1, wherein the vehicle body (1) is provided with a swing-fixing mechanism (11) that allows the mowing device (6) to be swing-fixed and released, and the swing-fixing mechanism (11) is connected to the swing lever (10) of the operating unit (9) by a fixing cable (12) and a swing cable (13), and when the handle rod (8) is located at the rear of the vehicle body (1), the operator at the rear of the operating unit (9) can operate the swing lever (10) in the left-right direction to swing-fix and release the mowing device (6) via the fixing cable (12), and by operating the swing lever (10) in the front-back direction, the mowing device (6) can be swinged up and down via the swing cable (13) to adjust the mowing height.

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