Transmission arrangement for a slope mower

Abstract

To provide a transmission structure capable of maintaining durability even when torsion in the lateral direction and displacement in the vertical direction simultaneously act on a V-belt.SOLUTION: A mowing deck 3 is liftably constituted by two pairs of front and rear parallel links 8, 9 having a front end part of a link pivoted on a vehicle body 5 side and a rear end part pivoted on a mowing deck 3 side and having a front upward inclination. The drive shaft 11, the blade shaft 2, and the counter shaft 14 are arranged in this order from the front in a plan view, and the power generation belt 58, the drive belt 10, and the mowing belt 19 are arranged in this order from the top in a plan view, and an imaginary center line L extending between the front and rear support members 1616 and for tilting and rotating the engine base 15 and a belt line A1 when the mowing deck 3 is set at the intermediate position C are substantially parallel to each other in a side view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a blade transmission device for a grass cutter that, when mowing on sloping ground, has an engine that drives the blade shaft in conjunction with the grass cutter body, which is fitted with a grass cutter deck that mounts the grass cutter blade shaft, rotated at an angle relative to the body and rotated to a vertical position, thereby stabilizing the center of gravity of the grass cutter.The device simplifies the transmission mechanism from the drive shaft on the engine side to the blade shaft of the grass cutter deck, allowing for accurate and smooth transmission regardless of whether the engine mounting position is changed or the grass cutter deck is raised or lowered. [Background technology]

[0002] When a lawnmower travels on an inclined mowing surface, a known technology is to tilt the engine mounted on the mowing vehicle body in accordance with the inclination of the vehicle body detected by an inclination sensor, thereby maintaining a reliable transmission state even while twisting the V-belt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-005554 Summary of the Invention [Problem to be solved by the invention]

[0004] In the transmission configuration of the grass cutter described in Patent Document 1, the belt line shifts up and down when the grass cutting deck is lowered, so if the range of lifting and lowering of the grass cutting deck is increased, there is a problem that the durability of the V-belt deteriorates when the grass cutting deck is lowered to perform grass cutting work. [Means for solving the problem]

[0005] The invention described in claim 1 is a mowing deck 3 on which a blade shaft 2 of a mowing blade 1 is mounted, which is attached to a vehicle body 5 that travels on a pair of left and right crawlers 4 via two pairs of front and rear parallel links 8, 9 in a forward ascending inclined form, with the front end of the link pivoted around link shafts 6, 7 on the vehicle body 5 side and the rear end of the link pivoted around link shafts 36, 37 on the mowing deck 3 side so that it can rotate freely up and down; an engine base 15 is provided above the mowing deck 3, and an engine E is mounted on the engine base 15, and the engine E projects downward from the engine base 15. A two-stage drive pulley 12 is attached to the drive shaft 11, which is connected to the engine E. A generator 25 is provided behind the engine E when the drive is by an electric motor, and a hydraulic pump is provided behind the engine E when the drive is by a hydraulic motor. A generator pulley 57 is attached to a generator shaft 56 which protrudes downward from the engine base 15. A counter shaft 14, which has two-stage counter pulleys 13 attached thereto, is erected behind the mowing deck 3 of the blade shaft 2. A blade pulley 17 is attached to the blade shaft 2 which protrudes upward from the mowing deck 3. An upper V-pulley 55 of the drive pulley 12 is attached to the generator shaft 56 which protrudes downward from the engine base 15. and the generator pulley 57, a generator belt 58 is stretched between the lower drive pulley 12b and the upper counter pulley 13a, a drive belt 10 is stretched between the lower pulley 21 of the counter pulley 13 and the blade pulley 17, and a reaping belt 19 having a reaping clutch 20 that can be tensioned and relaxed by a tension pulley 18 is stretched between the lower pulley 21 of the counter pulley 13 and the blade pulley 17, and the engine base 15 is configured to be tiltable and rotatable left and right around support members 16 provided at the front and rear ends of the engine base 15 at positions that are lower than the engine E mounting surface by a predetermined height H and at approximately the center in the left and right directions, The center line L is an imaginary straight line in the front-to-rear direction between the front and rear support members 16, 16, and the intermediate position C of the grass cutting deck 3 is set at a position where the center line L, which is approximately horizontal in a side view, and the belt line A1 of the drive belt 10 are approximately parallel, and the intermediate position C is approximately halfway between the highest and lowest heights of the grass cutting deck 3, and the grass cutting height can be adjusted within the range from the highest to the lowest height of the grass cutting deck 3 by moving the grass cutting deck 3 up and down.This is the configuration of the blade transmission device of a grass cutter.

[0006] The invention as set forth in claim 2 is configured such that the blade transmission device of the brush cutter has an engine mounting surface 67 provided in front of the engine base 15, the engine mounting surface 67 being lower by a predetermined height T than the rear of the engine base 15.

[0007] The crawler 4 is driven by a motor mounted on the vehicle body 5, causing the mower to travel and mow. Driven by the engine E, the drive shaft 11 is rotated, and the blade 1 of the mowing deck 3 is rotated via the drive belt 10, counter shaft 14, mowing belt 19, mowing clutch 20, etc., allowing mowing work to be performed. When the mowing clutch 20 operates to the transmission-off position, the rotation transmission of the mowing belt 19 stops, stopping the rotation of the blade 1 and stopping the mowing operation.

[0008] When performing grass cutting work, the grass cutting deck 3 is raised or lowered to the desired height, the cutting clutch 20 is operated to the transmission-on position, and the grass cutting work can be performed by driving and rotating the cutting belt 19, blade shaft 2, and blade 1 from the counter shaft 14.

[0009] During such mowing work, if the surface on which the mowing is being performed is significantly inclined to the left or right, this is detected by an inclination sensor or by manual operation, etc., so that the mounting position of the engine E is always maintained vertically regardless of the left or right inclination of the vehicle body 5, or the position is controlled to an angle that does not exceed the engine E's operating limit inclination angle, thereby preventing further inclination and oscillation of the mowing machine body or rollover, preventing deviation in the mowing operation, and maintaining stability in the mowing operation.

[0010] When the engine E is tilted and rotated to the left or right of the mower to change and control the mounting posture, the engine base 15 on which the engine E is mounted is rotated around a support shaft 16 along the center line L toward the uphill side of the slope in accordance with the left or right tilt posture of the vehicle body 5, and the posture is controlled.

[0011] In this type of transmission, the mowing clutch 20 that transmits power to the blade shaft 17 is configured to engage and disengage the clutch by tensioning and loosening the mowing belt 19 between the counter shaft 21 and the blade shaft 17 with a tension pulley 18. Therefore, even if the mowing deck 3 is raised or lowered, or even if the engine E is tilted or rotated, the belt clutch 20 can smoothly, accurately, and easily engage and disengage the clutch.

[0012] The mowing deck 3 is raised and lowered relative to the vehicle body 5 via parallel links 8, 9 in a forward upward inclination form supported by two pairs of link shafts 6, 7 at the front and rear of the vehicle body 5, and the mowing deck 3 can be raised and lowered while maintaining a substantially horizontal posture in the fore-and-aft direction. An intermediate position C is set approximately halfway between the highest and lowest heights of the mowing deck 3, and at this intermediate position C, the belt line A1 of the drive belt 10 stretched between the lower drive pulley 12b of the drive shaft 11 and the upper pulley 21 of the counter shaft 14 is set to be substantially parallel in a side view to an imaginary center line L in the fore-and-aft direction, which extends between the front and rear support members 16, 16 and serves as a pivot point for the left-right tilt of the engine base 15.

[0013] When the mowing deck 3 is lowered below the intermediate position C to perform mowing power transmission, the drive belt 10 between the drive shaft 11 and counter shaft 14 rotates downward and toward the front due to the parallel links 8, 9 in a forward ascending inclination configuration as the mowing deck 3 descends. Similarly, when the mowing deck 3 is raised above the intermediate position C to perform mowing power transmission, the drive belt 10 between the drive shaft 11 and counter shaft 14 rotates upward and toward the rear as the mowing deck 3 rises. Therefore, vertical deviation of the belt line of the drive belt 10 and changes in spacing are absorbed and mitigated, ensuring accurate and stable power transmission. [Effects of the Invention]

[0014] The engine E, which transmits the blade shaft 2 of the mowing deck 3 that rises and falls relative to the vehicle body 5, is configured to be tiltable and rotatable left and right around a support member 16 that runs along the center line L of the mower body 5, so that the left and right tilting posture of the engine E can be controlled symmetrically with respect to the center line L of the vehicle body 5, allowing mowing work to be performed with approximately the same operating feel on ground that slopes down to the left and on ground that slopes down to the right relative to the direction of mowing travel. In particular, when the mowing deck 3 is raised or lowered above or below the intermediate position C relative to the vehicle body 5 via the parallel link 8, 9 mechanism, the belt line of the drive belt 10 stretched between the lower drive pulley 12b of the drive shaft 11 and the upper counter pulley 13a of the counter shaft 14 is shifted in the vertical direction, and when the engine base 15 tilts and rotates from this state, the drive belt 10 is also twisted. However, the rotation of the parallel links 8, 9 operates to bias the counter shaft 14 and the counter pulley 13 to a position slightly rearward and upward or slightly forward and downward, thereby absorbing and alleviating excessive tension and slack in the drive belt 10 and preventing the drive belt 10 from coming off the drive pulley 12 and counter pulley 13, allowing for smooth tension transmission and power transmission of the blade shaft 2, and enabling stable transmission and mowing work.

[0015] In addition, to change the transmission force of the blade shaft 2 on the mowing deck 3, there is a mowing clutch 20 that engages and disengages the transmission rotation of this blade shaft 2.The mowing clutch 20 in this invention engages and disengages the transmission by tensioning and loosening the mowing belt 19 that is stretched between the counter pulley 13 on the counter shaft 14 aligned along the center line L and the blade pulley 17 on the blade shaft 2 with a tension pulley 18, and this allows for stable mowing work to be performed without being affected by the up and down movement of the mowing deck 3 or fluctuations in the up and down tilt of the engine E.

[0016] Furthermore, since the engine base 15 is configured to tilt and rotate left and right around the support members 16, 16 above the counter pulley 13, a predetermined amount of rotation space is required between the counter pulley 13 and the engine base 15. In this space, the generator belt 58 transmission between the upper pulley 55 of the drive shaft 11 and the generator 25 or the generator pulley 57 of the hydraulic pump is arranged, and the generator belt 58, drive belt 10, and harvesting belt 19 are arranged and transmitted in this order from top to bottom, so the height of the engine base 15 can be configured low, and the vehicle body 5 can be maintained in a stable state with a low center of gravity.

[0017] Furthermore, the intermediate position C of the mowing deck 3 is set to a position where the center line L, which is approximately horizontal when viewed from the side, and the belt line A1 of the drive belt 10 are approximately parallel, so the vertical deviation of the drive belt 10 is approximately equal when the mowing deck 3 is at its highest height and when it is at its lowest height, and even if the lifting range of the mowing deck 3 is increased, the increase in vertical deviation can be suppressed, thereby improving the durability of the drive belt 10.

[0018] Furthermore, because an engine mounting surface 67 that is lower by a predetermined height T than the rear is provided in front of the engine base 15, even when the mowing deck 3 is in the intermediate position C and the belt line A1 of the drive belt 10 that is stretched between the lower drive pulley 12b of the drive shaft 11 and the upper pulley 21 of the counter shaft 14 and the imaginary center line L that is a straight line in the front-to-rear direction that spans the front and rear support members 16, 16 and serves as the fulcrum for the left-to-right tilt rotation of the engine base 15 are approximately parallel in a side view, clearance can be secured above the counter pulley 13, so the maximum height of the mowing deck 3 can be set high, which means that the lifting range of the mowing deck 3 can be increased. Furthermore, by lowering the mounting position of the heavy engine E, the center of gravity can be lowered, improving stability on slopes. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. [Figure 2] FIG. 10 is a partial side view showing the change in the belt transmission mechanism caused by the lifting and lowering of the mowing deck. [Figure 3] FIG. 4 is a side view of the mower showing the attachment state of the mowing deck by the parallel links and the lifting and lowering operation. [Figure 4] FIG. 4 is a plan view of the brush cutter showing the belt transmission mechanism of the blade shaft. [Figure 5] FIG. 4 is a partial plan view showing a belt transmission mechanism and an operating mechanism of the mowing clutch. [Figure 6] FIG. 2 is a plan view of the brush cutter showing the generator transmission mechanism. [Figure 7] FIG. 4 is a front view showing the tilting and rotating state of the engine relative to the vehicle body when traveling on an inclined surface. [Figure 8] FIG. 4 is a front view showing the left and right tilt rotation states of the engine relative to the vehicle body. [Figure 9] FIG. [Figure 10] FIG. 2 is a block diagram of a controller for performing grass cutting work using a grass cutter. [Figure 11] FIG. 10 is a plan view of a transmitter that transmits a control signal to a controller that causes the grass cutter to perform grass cutting work. [Figure 12] FIG. 2 is a plan view showing the cooling configuration using fans on the top of the generator. DETAILED DESCRIPTION OF THE INVENTION

[0020] As shown in the drawings, the brush cutter is equipped with a pair of left and right travel crawlers 4 made primarily of rubber, and is mounted at the upper rear end of the vehicle body 5. The travel motor M that drives the crawlers 4, a transmission case 22, and two controllers 23 (top and bottom) for traveling, mowing, and other operations are mounted at the front end. The front end is equipped with an engine E for driving the blade shaft 2 of the mowing deck 3. The front and rear center sections are equipped with a battery 24a for starting the engine E, a fuel tank 26, a battery 24b for driving the motor M, a generator 25 for charging the battery 24b, and a rectifier box 101. A fan 97 that operates in conjunction with the generator 25 is mounted on the top surface of the generator 25 and is covered from above by a fan cover 98. Guard frames 28 are mounted at the front and rear of the upper section of the vehicle body 5, forming an arch shape and covering guard pipes 27 at the front and rear ends and the middle section of the vehicle body 5. A cover 29 is provided to protect the upper sides of the various mounted equipment.

[0021] The crawlers 4 are hung on end rollers 32, intermediate rollers 33, and a drive sprocket 34 at the rear end, which are arranged in the front-to-rear direction of left and right track frames 31 attached to support legs 30 that stand upright from both the left and right ends of the vehicle body 5.The left and right traveling motors M transmit rotation of the sprocket shafts 35 via transmission gears in the transmission case 22, thereby rotating the left and right crawlers 4 and enabling the vehicle to travel or steer.

[0022] At the bottom of the vehicle body 5, at the interval (tread portion) between the right crawlers 4, 4, a mowing deck 3, on which a blade shaft 2 of a blade 1 for cutting grass is mounted, is pivotally and detachably attached to the rear ends of parallel links 8, 9 that move up and down by link shafts 36, 37. The front ends of these parallel links 8, 9 are rotatable about lateral link shafts 6, 7 that are attached to bearing brackets formed at the front ends of both the left and right sides of the vehicle body 5. The rear ends of the four left and right parallel links 8, 9 are pivotally attached by link shafts 36, 37 to the rear ends of the four left and right parallel links 8, 9, and the mowing deck 3 is raised and lowered, maintaining a position parallel to the ground to be mowed, via lift links 39, by the rotation of a lift arm 38 that is rotated by the extension and contraction of an electric cylinder 50. At the highest height of the mowing deck 3, the upper surface of the ceiling of the mowing deck 3 is close to the bottom of the vehicle body 5, and is set to be at the upper limit of the mowing height. Furthermore, when the mowing deck 3 is lowered to its lowest height, the mowing height of the grass cut by the blade 1 rotating inside the mowing deck 3 is at its lowest position, and if gauge wheels are attached to the front and rear ends of the mowing deck 3, this minimum mowing height position can be maintained on the ground. Furthermore, guard chains 102 are attached to the frame at the front and rear of the mowing deck 3. The guard chain 102 has a rubber plate on the mowing deck 3 side, and a chain hanging on the outside so as to follow the rubber plate, which can effectively prevent stones and other objects from flying about that are forcefully ejected from the mowing deck 3 during mowing work.

[0023] The mowing deck 3 has a vertical blade shaft 2 rotatably mounted in the center, and the center of a blade stay 40, with the blade 1 disposed on the outer periphery, is attached to the lower end of this blade shaft 2. On the upper side of the mowing deck 3, a blade pulley 17 in the form of a V-pulley is attached to the upper end of the blade shaft 2, which engages with a mowing belt 19 made of a V-belt with a V-shaped cross section and guides its rotation.

[0024] A counter shaft 14 is rotatably erected above the mowing deck 3, just behind the blade shaft 2 and parallel to the blade shaft 2, and a V-pulley-type counter pulley 13 is provided on this counter shaft 14, with an upper counter pulley 13a at its upper end and a lower pulley 21 at its lower end. A V-belt-type mowing belt 19 is stretched between the lower pulley 21 of the counter shaft 14 and the blade pulley 17 of the front blade shaft 2, and power transmission from the counter shaft 14 to the blade shaft 2 can be switched on and off by tensioning and loosening a tension pulley 18 on the rotating outer periphery of the mowing belt 19. A clutch arm 41 of the tension pulley 18 is pivotally mounted on a pivot shaft 42 on the upper surface of the mowing deck 3 at the outer periphery of the lower pulley 21, and an operating wire 43 connected to this clutch arm 41 is connected to an operating arm 45 which is rotated about an arm shaft 46 by an electrically extended and retracted mowing clutch 20 and an electric cylinder 44 for braking the blade shaft 2, and the extension and retraction of this electric cylinder 44 engages and disengages the mowing clutch 20 by the tension pulley 18 (see Figures 4 and 5).

[0025] In addition, a brake arm 47 is rotatably mounted around an arm shaft 48 on the upper surface of the mowing deck 3 around the blade pulley 17. The brake arm 47 fits into and slides against the V-groove portion of the blade pulley 17 to brake the rotation of the blade shaft 2, and is connected to an operating arm 45, which is rotated around the arm shaft 46 by the electric cylinder 44, by an operating wire 49. By pushing and rotating the electric cylinder 44, the operating arm 45 can be rotated from the cut-off position b of the mowing clutch 20 to the on position a, pulling the wire 43 and tensioning the tension pulley 18 and clutch arm 41 of the mowing clutch 20 against the mowing belt 19, thereby placing the mowing clutch 20 in a transmission-on position. Also, at this time, when the operating arm 45 is rotated from the brake position f to the brake release position e, the operating wire 49 is pulled, causing the brake arm 47 to rotate around the arm shaft 48, and the brake shoe 47s, which is fitted and pressed against the V-pulley groove of the blade pulley 17, is moved away from the outside in the radial direction, releasing the braking force and allowing smooth transmission of cutting power by the cutting belt 19 from the counter shaft 14 to the blade shaft 12.

[0026] Furthermore, the mowing clutch 20 and brake arm 47, which are operated via the electric cylinder 44, operating arm 45, operating wires 43, 49, clutch arm 41, brake arm 47, etc., are operated by shortening the electric cylinder 44 and rotating the operating arm 45 from clutch-on position a to clutch-off position b, so that the mowing clutch 20 moves away from the mowing belt 19 via the operating wires 43, 49 to a transmission-released position, and the brake shoe 47s of the brake arm 47 slides into contact with the V-groove portion of the blade pulley 17 of the blade shaft 2, putting the blade shaft 2 into a braking state.

[0027] The engine base 15 has trapezoidal bracket arms 51 formed on the front and rear edge portions of its bottom, which reinforce the support structure for the engine E and the like, and also facilitate the setting of a range of left and right rotation around a support member 16 on the center line L of the vehicle body 5. A support metal 53 is provided at the center position in the width direction of horizontal beams 52 extending from left to right at the front and rear of the vehicle body 5, and the support member 16 provided at the central lower end of the bracket arm 51 is fitted and supported between these front and rear support metals 53, so that the engine base 15, which is normally positioned in a horizontal position in the left-right direction, can rotate freely left and right over an appropriate range of angle θ with respect to a vertical line Y of the vehicle body 5. The rotation of the engine base 15 is controlled by an inclination sensor S1 that detects the left and right inclination angle α of the ground being mowed as the vehicle body 5 travels, and an electric cylinder 54 that rotates the engine base 15 left and right relative to the vehicle body 5. The effective left and right angle θ ranges are preset to several angles (for example, the control angle θ is 10°, 18°, 25°), and angle control is performed manually or automatically, so that the mounting position of the engine E on the sloping ground to be mowed can always be maintained in a vertical position Y or below the angle within the allowable range of inclination of the engine E. In addition, a gas damper 103 is provided on the engine base 15, and the gas damper 103 always applies pressure in the direction pressing the electric cylinder 54, so that rattles are less likely to occur in the engine base 15 or other peripheral parts. When the engine base 15 tilts, the gas damper also expands and contracts in accordance with the expansion and contraction of the electric cylinder 54, and the pressure is constantly applied, so that the components around the engine base 15 are less likely to become loose or be damaged.

[0028] An engine E is mounted on the front of the engine base 15, and at the rear thereof are mounted batteries 24a, 24b for starting the engine E and driving the motor M, a fuel tank 26, a generator 25, etc., which are arranged and attached so that the overall vehicle weight is distributed symmetrically on the left and right sides of the support member 16. The drive shaft 11 of the engine E protrudes vertically downward at the front of the engine base 15, and this drive shaft 11 is formed with pulleys with upper and lower V-shaped belt grooves, and a drive belt 10 is wound between the lower drive pulley 12b and the upper counter pulley 13a of the counter pulley 13 at the rear of the mowing deck 3, with a tension pulley 60 tensioned to constantly transmit rotation. Furthermore, a virtual longitudinal straight line extending between the front and rear support members 16, 16 at the bottom of the engine base 15 is set as a center line L, which is located at the lateral center of the brush cutter body 5. This center line L and a belt line A1 at the vertical center of the drive belt 10 at the intermediate position C of the mowing deck 3 are set parallel and at approximately the same height in a side view. An upper V-pulley 55 for driving the generator 25 is provided above the drive pulley 12. A generator belt 58 is stretched between the upper V-pulley 55 and a generator pulley 57 attached to a generator shaft 56 of the generator 25 mounted at the rear of the upper V-pulley 55, and a tension pulley 59 is tensioned to constantly transmit rotation. A rotating shaft 99 that rotates in conjunction with the generator shaft 56 is provided vertically on the top surface of the generator 25. A fan 97 is attached to the rotating shaft 99 and is covered from above by a fan cover 98. The fan cover 98 has multiple intake holes on the top surface and exhaust holes on the side, and is open on the bottom surface. When the generator shaft 56 and the rotating shaft 99 are driven by power transmitted from the engine E, the fan 97 rotates, generating cooling air 100 downward and in the circumferential direction of the fan 97. The cooling air 100 generated downward flows along the side of the generator 25, thereby cooling the generator 25. Meanwhile, the cooling air 100 generated from the side of the fan cover 98 in the circumferential direction of the fan 97 blocks heat transmitted from the engine E and cools the batteries 24a, 24b, fuel tank 26, and the like, which are located around the generator 25. In addition, the cooling air 100 generated in the circumferential direction stirs the air inside the cover 29, thereby lowering the ambient temperature inside the cover 29.

[0029] Furthermore, the engine E is mounted on an engine mounting surface 67 in front of the engine base 15, which is set at a position that is lower by a predetermined height T than the mounting surfaces of the generator 25 and the fuel tank 26. In order to make the belt line A1 and the center line L parallel to each other at the intermediate position C, the lower drive pulley 12b and the upper counter pulley 13a must be at approximately the same height. In order to increase the lifting range of the mowing deck 3, it is necessary to ensure clearance with the engine base 15, which is located above the counter pulley 13, when the mowing deck 3 is at its highest height. Therefore, the height of the upper counter pulley 13a at the intermediate position C is positioned below the end of the drive shaft 11 of the engine E. In this case, it is not preferable to position the lower drive pulley 12b below the end of the drive shaft 11 of the engine E in order to make the belt line A1 parallel to the center line A1, as this increases the load on the drive shaft 11. Therefore, as described above, by setting the engine mounting surface 67 in front of the engine base 15 low, it is possible to lower the mounting position of the engine E itself, position the lower drive pulley 12b low, and ensure clearance above the counter pulley, thereby increasing the lifting range of the mowing deck 3. Furthermore, by mounting the engine E, which is a heavy object, in a low position, it is possible to improve running stability on slopes.

[0030] In the abdominal section of the brush cutter body 5, the drive shaft 11 and the generator shaft 56 of the generator 25 hang down from the upper side of the engine base 15, and the upper end of the blade shaft 2 protrudes from the upper side of the mowing deck 3 at the bottom, and the counter shaft 14 is erected in a parallel arrangement with a front-to-rear distance on the center line L in the fore-to-aft direction. When the height of the mowing deck 3 is set to the intermediate position C, the upper counter pulley 13a of the counter shaft 14 is at approximately the same height as the lower drive pulley 12b at the lower end of the drive shaft 11, and the drive belt 10 stretched between the lower drive pulley 12b and the upper counter pulley 13a is configured to be stretched in a substantially horizontal manner from front to back. In this state, the drive belt 10, the mowing belt 19, and the generator belt 58 are stretched horizontally and parallel to each other. In addition, when the drive shaft 11, blade shaft 2, and counter shaft 14 are arranged side by side in a plan view, all of the shafts may be aligned with the center line L, but the drive shaft 11 does not necessarily have to be arranged in the center position of the left and right of the vehicle body 5, and may be offset to the left or right depending on the arrangement of the drive shaft 11 of the engine E, and when a pair of left and right blade shafts 11 are provided, the blade shafts 11 may be arranged to be distributed to the left and right of the center line L in a plan view.

[0031] The drive belt 10, which is a V-shaped belt stretched between the lower drive pulley 12b and the upper counter pulley 13a, has a tension pulley 60 provided near the outer periphery of the lower drive pulley 12b to constantly tension the drive belt 10 in a power transmission mode. The tension pulley 60 is rotatably provided at the tip of a tension arm 92 pivoted on a pivot shaft 91 of the upper engine base 15, and tensions the drive belt 10 by a spring 93. The tension pulley 60 presses against the back surface of the V-shaped drive belt 10 and is configured as a flat pulley (roll shape). The vertical height of the pulley 60 is formed slightly wider than the contact and rolling width of the drive belt 10. This causes the drive belt 10 to be slightly biased up and down when the mowing deck 3 is raised and lowered, and even if the engine base 15 swings left and right, the drive belt 10 is unlikely to come off or derail.

[0032] 9, 62 is a fuel filler lid, which is provided on the fuel filler port of the cover 29. 63 is a fuel filler cap for the fuel tank 26, 68 is a power switch, 64 is an emergency stop switch, 65 is an hour meter, and 66 is a throttle lever.

[0033] To control the mowing travel of the mower, the input side of the controller (having a CPU) 23 is provided with a receiver 71 that receives transmissions from a radio transmitter (transmitter) 70, an inclination sensor S1 that detects the left and right inclination angle of the body 5, a left and right traveling motor M, and temperature sensors S2, S3, and S4 that detect the temperature of the generator 25, as well as a variable resistor R1 for the engine tilt cylinder, a variable resistor R2 for the mowing height electric cylinder, a variable resistor R3 for the mowing clutch electric cylinder, a variable resistor R4 for the choke electric cylinder, etc. (see Figure 10).

[0034] Also, on the output side of the controller 23, various warning lights 72, an error display unit 73 that also serves as a battery remaining amount meter, etc. are provided. Also provided are an electric cylinder 54 that tilts the engine E, an electric cylinder 50 for adjusting the mowing height, an electric cylinder 44 that engages and disengages the mowing clutch 20, an electric cylinder 69 that performs choke operation, etc. Furthermore, respective control circuits 74, 75 of the motors M that drive the drive sprockets 34 of the left and right crawlers 4 are provided.

[0035] The transmitter 70 has a signal transmission / reception antenna P, a power switch 76 on the lower upper surface, a forward / reverse lever 77 that can be rotated forward and backward to move the mower forward and backward, and a swing lever 78 that can be rotated left and right to control the direction of travel and swing. An LCD display 79 is provided on the top of the transmitter 70 to display the mower's running status, working status, errors, etc. An operation dial 80 for operating the LCD display 79 is provided on the lower right. Also provided in the upper center are a dial 81 that can adjust the maximum speed and a dial 82 that adjusts the mowing height. To the right of these are a mowing clutch lever 83 that engages and disengages the mowing clutch 20, and an eco switch 90 that switches the engagement and disengagement of the mowing clutch 20 and the engine E. An engine stop lever 87 and an engine start switch 86 are provided on the upper right. Meanwhile, the left side is equipped with a maintenance switch 94 that switches between automatic and manual tilt control of the engine base 15, and furthermore, a choke switch 95 and other devices are located on the upper left. The start switch 86 rotates the starter while it is pressed, and stops the starter if it is held down for five seconds or more. The starter does not rotate when the engine stop lever 87 is in the stop position. By operating the dial 82 that adjusts the cutting height, the maintenance switch 94, and the choke switch 95, the electric cylinder 50, 54, or 69 can be extended or retracted to raise or lower the mowing deck 3, change the tilt of the engine E, or operate the choke. [Explanation of symbols]

[0036] 1 blade 2 blade shaft 3. Grass-cutting deck 4. Crawler 5. Body 6 Link shaft 7 Link shaft 8 Parallel Link 9 Parallel link 10 Drive belt 11 Drive shaft 12 Drive pulley 12b Lower drive pulley 13 Counter pulley 13a Upper counter pulley 14 Counter shaft 15 engine base 16 Support member 17 Blade pulley 18 Tension pulley 19 Harvesting Belt 20 Reaping Clutch 21 Lower pulley 25 Generator 36 Link shaft 37 Link shaft 55 Upper V pulley 56 Power generating shaft 57 Power generating pulley 67 Engine mounting surface A1 Beltline C Intermediate position E-Engine H specified height L Centerline Medium motor T specified height

Claims

【Request Item 1】 A mowing deck (3) on which a blade shaft (2) of a mowing blade (1) is mounted is attached so as to be able to move up and down relative to a vehicle body (5) which travels on a pair of left and right crawlers (4) via two pairs of front and rear parallel links (8, 9) in a forward ascending inclined form, the front ends of the links being pivotally supported around link shafts (6, 7) on the vehicle body (5) side and the rear ends of the links being pivotally supported around link shafts (36, 37) on the mowing deck (3) side, and an engine base (15) is provided above the mowing deck (3), and an engine (E) is mounted on the engine base (15) and protrudes downward from the engine base (15). A two-stage drive pulley (12) is attached to the drive shaft (11), and a generator (25) is provided behind the engine (E) when the drive is by an electric motor, and a hydraulic pump is provided when the drive is by a hydraulic motor. A generator pulley (57) is attached to a generator shaft (56) protruding downward from the engine base (15). A counter shaft (14) having two-stage counter pulleys (13) attached thereto is erected behind the mowing deck (3) of the blade shaft (2). A blade pulley (17) is attached to the blade shaft (2) protruding upward from the mowing deck (3). An upper V-pulley ( A V-belt (58) is stretched between the lower drive pulley (12b) and the upper counter pulley (13a), a drive belt (10) is stretched between the lower pulley (21) of the counter pulley (13) and the blade pulley (17), and a reaping belt (19) having a reaping clutch (20) that can be tensioned and relaxed by a tension pulley (18) is stretched between the lower pulley (21) of the counter pulley (13) and the blade pulley (17). The engine base (15) is mounted on a support member (16) at a predetermined height (H) lower than the engine (E) mounting surface at the front end and rear end of the engine base (15) and in a left-right inclined circle. a center line (L) that is an imaginary straight line in the front-to-rear direction extending between the front and rear support members (16), (16), and a position where the center line (L), which is in a substantially horizontal state in a side view, and the belt line (A1) of the drive belt (10) are substantially parallel to each other, is set as an intermediate position (C) of the grass mowing deck (3), the intermediate position (C) being approximately halfway between the highest and lowest heights of the grass mowing deck (3), and the grass mowing height can be adjusted within the range from the highest to the lowest height of the grass mowing deck (3) by raising and lowering the grass mowing deck (3).

2. 2. The blade transmission device for a grass cutter according to claim 1, wherein an engine mounting surface (67) is provided in front of the engine base (15) and is lower by a predetermined height (T) than the rear of the engine base (15).

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