JP7571508B2 - Grass cutting machine - Google Patents

Description

The present invention relates to a grass cutting machine capable of mowing grass on slopes.

A conventional grass cutter capable of mowing steep slopes is described in Patent Document 1. In this grass cutter, the engine is configured to be tiltable left and right depending on the angle of inclination of the ground, and a grass cutting deck is provided below it that can be raised and lowered freely. Power is transmitted between the drive pulley 12 and counter pulley 13, and between the counter pulley 13 and blade pulley 17 by a drive belt 10 and a cutting belt 19.

JP 2020-5554 A

In the grass cutter of Patent Document 1, power is transmitted between the drive pulley 12 and the counter pulley 13 by the drive belt 10, which is constantly tensioned. For example, when the grass cutting deck 3 is lowered, the counter pulley 13 is lower than the drive pulley 12, and the belt line of the drive belt 10 becomes inclined (rearward downward inclination) in a side view. The greater the degree of inclination, the greater the load on the drive belt 10. Furthermore, the grass cutter of Patent Document 1 is configured to tilt the engine E to the left and right, and tilting the engine E to the left and right also applies a twisting action to the drive belt 10, which significantly deteriorates the durability of the drive belt 10 and leads to the drive belt 10 breaking in a short period of time. In addition, the continuous use tilt limit angle of a general-purpose gasoline engine with a wet sump system that uses oil stored in the engine crankcase for internal lubrication is usually limited to 20 to 25 degrees, so in order to mow on a slope steeper than this angle, the engine must be tilted toward the mountain so that the engine's inclination is below the tilt limit angle. The objective of the present invention is to provide a mowing machine equipped with an engine left/right tilt mechanism that can mow on slopes steeper than the continuous use limit angle of a general-purpose gasoline engine, which improves the durability of the drive V-belt and protects the engine.

An engine pulley 4 is attached to an engine output shaft 3 that protrudes downward from an engine base 2 on which an engine 1 is mounted, and a mowing device 6 equipped with a grass cutting blade 5 that rotates approximately horizontally is provided below the engine base 2 so as to be movable up and down relative to a vehicle body 7, the engine pulley 4 and a counter pulley 10 provided on the side of the mowing device 6 are disposed spaced apart in the front-to-rear direction, a cutting blade pulley 9 that is attached to a blade shaft 8 of the grass cutting blade 5 is disposed in the front-to-rear intermediate portion between the engine pulley 4 and the counter pulley 10, and power is transmitted between the engine pulley 4 and the counter pulley 10 and between the counter pulley 10 and the cutting blade pulley 9 by V-belts 11, 12, and the engine pulley 4 and the counter pulley 10 and the counter pulley 10 and the cutting blade pulley 9 are configured to be capable of transmission by V-belts 11, 12, and the engine 1 can be automatically tilted in the left-to-right direction of the vehicle body 7 based on the detection results of a front-to-rear inclination angle detection means FB that detects the inclination angle of the vehicle body 7 and a left-to-right inclination angle detection means LR. The tilt angle is set within a range of at least 10 degrees or more, and when traveling on plane H, engine 1 is in an approximately vertical state V with respect to the horizontal direction of vehicle body 7, and when the left and right tilt is in a state where the left and right tilt is from 0 degree to a predetermined mountain side set angle Y, the tilt angle of engine 1 is maintained in the approximately vertical state V with respect to vehicle body 7, and when the predetermined mountain side set angle Y is detected , engine 1 is controlled to tilt toward mountain side KY of inclined surface K, and when traveling on inclined surface K in the contour line direction, if the detection angle of the left and right tilt angle detection means LR is changing in a direction to become steeper, the predetermined mountain side set angle Y for tilting engine 1 toward mountain side KY of inclined surface K and the predetermined valley side set angle T for tilting engine 1 toward valley side KT of inclined surface K are set to different angles if the detection angle of the left and right tilt angle detection means LR is changing in a direction to become gentler, and the predetermined valley side set angle T is set to an angle gentler than the predetermined mountain side set angle Y.

The predetermined peak side set angle Y is set within a range of 5 degrees below the limit angle G of continuous use of the engine 1.

In addition, when the longitudinal inclination angle detection means FB detects a displacement inclination angle that is less than the first set angle X1 and the detection angle of the left/right inclination angle detection means LR is changing in a direction that is becoming steeper, a left/right increasing longitudinal gentle inclination control P1 is executed in which a predetermined mountain side set angle Y is set within a range of 5 degrees below the continuous usable limit angle G of the engine 1, and when the longitudinal inclination angle detection means FB detects a displacement inclination angle that is equal to or greater than the first set angle X1, if the left/right inclination angle detection means LR detects a displacement inclination angle that is equal to or greater than a mountain side inclination set angle y that is gentler than the predetermined mountain side set angle Y, the control is transitioned to a left/ right increasing longitudinal steep inclination control Q1 in which the engine 1 is tilted toward the mountain side KY of the inclined surface K.

In addition, when the longitudinal inclination angle detection means FB detects a displacement inclination angle less than the first set angle X1 and the detection angle of the left/right inclination angle detection means LR is changing in a gentler direction, a left/right decreased longitudinal gentle inclination control P2 is executed to tilt the engine 1 toward the valley side KT of the inclined surface K at a predetermined valley side set angle T that is set at a tilt angle gentler than the predetermined mountain side set angle Y, and when the longitudinal inclination angle detection means FB detects a displacement inclination angle equal to or greater than the first set angle X1, the control is shifted to a left/right decreased longitudinal steep inclination control Q2 that does not tilt the engine 1 toward the valley side KT of the inclined surface K until the left/right inclination angle detection means LR detects a displacement inclination angle equal to or less than the valley side inclination set angle t that is gentler than the predetermined valley side set angle T.

Furthermore, after detecting a displacement tilt angle of equal to or greater than the first set angle X1 from a state of left/right increasing front/rear steep tilt control P1 or left/right decreasing front/rear steep tilt control P2, and transitioning to a state of left/right increasing front /rear steep tilt control Q1 or left/right decreasing front/rear steep tilt control Q2, the state of left/right increasing front/rear steep tilt control Q1 or left/ right decreasing front/rear steep tilt control Q2 is maintained until the front/rear tilt angle detection means FB detects the second set angle X2.

In addition, the predetermined mountain side setting angle Y and mountain side inclination setting angle y, and the predetermined valley side setting angle T and valley side inclination setting angle t, at which the engine 1 starts to tilt between the substantially vertical state V and the maximum left/right inclination state VM relative to the horizontal direction of the vehicle body 7, are configured to be set at multiple inclination angles.

The invention described in claim 1 is a grass cutting machine in which power is transmitted between the engine 1 and the grass cutting blade 5 by a V-belt and the engine 1 can be automatically tilted to the left and right of the vehicle body 7, the engine pulley 4 and the counter pulley 10 provided on the side of the cutting device 6 are arranged at a distance from each other in the front-to-rear direction, a cutting blade pulley 9 attached to the blade shaft 8 of the grass cutting blade 5 is arranged midway between the engine pulley 4 and the counter pulley 10, and power is configured to be transmitted between the engine pulley 4 and the counter pulley 10, and between the counter pulley 10 and the cutting blade pulley 9 by V-belts 11, 12. Therefore, the engine pulley 4 is arranged at the front of the vehicle body 7 and the counter pulley 10 is arranged at the rear of the vehicle body 7, and the axial distance between the engine pulley 4 and the counter pulley 10 can be made long, and when the cutting device 6 is raised and lowered, the inclination angle of the V-belt 11 in side view is gentler than when the axial distance between the engine pulley 4 and the counter pulley 10 is short, thereby reducing the burden on the V-belt 11. In addition, the specified mountain side set angle Y is set within a range where the left and right displacement inclination angle is at least 10 degrees, and when traveling on flat surface H, the engine 1 is in an approximately vertical state V with respect to the horizontal direction of the vehicle body 7, and the inclination angle of the engine 1 is maintained in the approximately vertical state V from this left and right inclination of 0 degrees until the specified mountain side set angle Y is detected, and when the specified mountain side set angle Y is detected, the engine 1 is controlled to tilt toward the mountain side KY of the inclined surface K, so that there is no twisting of the V-belt 11 due to the tilting of the engine 1, the overload condition is mitigated, and durability is improved. In addition, when traveling on an inclined surface K in the contour direction, a predetermined mountain side set angle Y for tilting the engine 1 toward the mountain side KY of the inclined surface K when the detection angle of the left-right inclination angle detection means LR is changing in a direction to become steeper, and a predetermined valley side set angle T for tilting the engine 1 toward the valley side KT of the inclined surface K are set to different angles when the detection angle of the left-right inclination angle detection means LR is changing in a direction to become gentler, and the predetermined valley side set angle T is set to an angle that is gentler than the predetermined mountain side set angle Y. Therefore, hysteresis control is performed which sets a difference between the angle at which the engine 1 tilts toward the mountain side KY of the inclined surface K and the angle at which it tilts toward the valley side KT, and the engine 1 does not repeat frequent tilting operations while traveling on an inclined surface K near the predetermined set angle.

In the invention described in claim 2, the specified mountain side set angle Y is set within a range of 5 degrees below the limit angle G at which the engine 1 can be continuously used. Therefore, the engine 1 maintains a substantially perpendicular state V with respect to the vehicle body 7 until the engine 1 reaches an inclination close to the limit angle G at which the engine 1 can be continuously used, thereby reducing the time that the V-belt 11 is twisted and significantly improving the durability of the V-belt 11.

In the invention described in claim 3 , when the longitudinal inclination angle detection means FB detects a displacement inclination angle less than a first set angle X1 and the detection angle of the left/right inclination angle detection means LR is changing in a direction to become steeper, a left/right increased gentle longitudinal inclination control P1 is executed in which a predetermined mountain side set angle Y is set within a range of 5 degrees less than the continuous usable limit angle G of the engine 1, and when the detection angle of the longitudinal inclination angle detection means FB detects a displacement inclination angle equal to or greater than the first set angle X1, if the left/right inclination angle detection means LR detects a displacement inclination angle equal to or greater than a mountain side inclination set angle y which is gentler than the predetermined mountain side set angle Y, a left/ right increased longitudinal inclination control P2 is executed in which the engine 1 is tilted toward the mountain side KY of the inclined surface K. Since the control transitions to steep tilt control Q1, during left/right increasing front/rear gentle tilt control P1 when the tilt of the engine 1 in the fore/aft direction is less than the first set angle X1, the engine 1 maintains an approximately vertical position V with respect to the vehicle body 7 and the V-belt 11 is less twisted, and when the tilt of the engine 1 in the fore/aft direction is equal to or greater than the first set angle X1, the control switches to tilting the engine 1 toward the mountain side KY of the inclined surface K before it reaches the specified mountain side set angle Y. Therefore, when tilting the engine 1 toward the mountain side KY, tilt control that takes into consideration the load balance on the V-belt 11 and the engine 1 is possible, and the durability of the V-belt 11 and the engine 1 can be improved in a well-balanced manner.

In the invention described in claim 4 , when the longitudinal inclination angle detection means FB detects a displacement inclination angle less than the first set angle X1 and the detection angle of the left/right inclination angle detection means LR is changing in a gentler direction, a left/right decreased longitudinal gentle inclination control P2 is executed to tilt the engine 1 toward the valley side KT of the inclined surface K at a predetermined valley side set angle T set at a tilt angle gentler than the predetermined mountain side set angle Y, and when the longitudinal inclination angle detection means FB detects a displacement inclination angle equal to or greater than the first set angle X1, the control is switched to a left/right decreased longitudinal steep inclination control Q2 which does not tilt the engine 1 toward the valley side KT of the inclined surface K until the left/right inclination angle detection means LR detects a displacement inclination angle equal to or less than the valley side inclination set angle t which is gentler than the predetermined valley side set angle T. Therefore, even when the engine 1 is tilted toward the valley side KT, tilt control taking into consideration the load balance on the V-belt 11 and the engine 1 is possible, and the durability of the V-belt 11 and the engine 1 can be improved in a well-balanced manner.

In the invention described in claim 5 , after detecting a displacement tilt angle of a first set angle X1 or more from a state of left/right increasing front/rear gentle tilt control P1 or left/right decreasing front/rear gentle tilt control P2, and transitioning to a state of left/right increasing front/rear steep tilt control Q1 or left/ right decreasing front/rear steep tilt control Q2, the state of left/right increasing front/rear steep tilt control Q1 or left/ right decreasing front/rear steep tilt control Q2 is maintained until the front/rear tilt angle detection means FB detects the second set angle X2. Therefore, once the mode of left/ right increasing front/rear steep tilt control Q1 or left/right decreasing front/rear steep tilt control Q2 is entered, the mode does not return to the mode of left/right increasing front/rear gentle tilt control P1 or left/right decreasing front/ rear gentle tilt control P2 , and the mode of left/right increasing front /rear steep tilt control Q1 is maintained until the tilt angle becomes equal to or less than the second set angle X2 set at an angle gentler than the first set angle X1. Alternatively, control in the mode of left/right reduced steep front/rear tilt control Q2 is maintained, so that even if the tilt angle continues to be near the first set angle X1, the engine 1 does not tilt frequently, and the load on the engine 1 and the V-belt 11 is reduced, while the operating time of each part for tilting the engine 1 is also reduced, thereby reducing the failure rate.

In the invention described in claim 6 , the specified mountain side set angle Y and mountain side inclination set angle y, and the specified valley side set angle T and valley side inclination set angle t, at which the engine 1 begins to tilt between the approximately vertical state V and the maximum left and right inclination state VM with respect to the horizontal direction of the vehicle body 7, are set at multiple stages of inclination angles, so that when the inclination angle reaches the specified mountain side set angle Y or the specified valley side set angle T, the engine 1 does not suddenly tilt to the maximum inclination state VM or the approximately vertical state V, making it possible to finely control the tilt of the engine 1, and in particular, it is possible to minimize the state of the maximum inclination state VM, in which the load on the V-belt 11 is heavy.

FIG. 4 is a partial rear view showing the engine in a tilted state. FIG. 4 is a partial rear view showing the engine in a tilted state. FIG. 11 is a rear view showing engine tilt control relative to the angle of the inclined surface. FIG. 11 is a rear view showing engine tilt control relative to the angle of the inclined surface. 4 is a cross-sectional side view showing the state of the V-belt when the reaping device is raised and lowered. FIG. FIG. Overall floor plan. FIG. 4 is an overall cross-sectional side view showing the lifting and lowering configuration of the reaping device. Block diagram of the controller. FIG. 4 is a development view showing the engine tilting state relative to the inclined surface and the vehicle body angle. FIG.

Based on the drawings, the grass cutting machine is equipped with a pair of left and right crawlers 20 made mainly of rubber material, and at the rear of the vehicle body 7 that runs, a travel motor M that drives the crawlers 4, a transmission case 21, and a controller 22 are provided. At the front, an engine 1 that drives the grass cutting blade 5 of the mowing device 6 is mounted. At the front and rear center, a battery 23 for starting the engine 1, a fuel tank 24, a battery 25 for driving the travel motor M, and an alternator 26 for charging this battery 25 are arranged on the engine base 2. At the upper part of the vehicle body 7, a guard frame 28 is provided in an arch-shaped form between the guard pipes 27 at the front and rear ends, and a cover 29 is provided to cover the upper part of each mounted device except for the engine 1. The grass cutting machine of the present invention can be wirelessly controlled, and the controller 22 is equipped with a receiver that receives control signals from a transmitter on the operator's side for driving and charging control, a front-rear inclination angle detection means FB that detects the inclination angle of the vehicle body 7, and a left-right inclination angle detection means LR. The longitudinal inclination angle detection means FB and the lateral inclination angle detection means LR use a single three-axis acceleration sensor to detect the inclination angle of the vehicle body 7.

The crawlers 20 are hung on the end wheels 32, intermediate wheels 33, rear end wheels 32a at the rearmost end, drive sprockets 34, and idle rollers 35 at the front end, which are arranged in the front-rear direction of the left and right track frames 31 attached to the support legs 30 that stand upright from the left and right ends of the vehicle body 7. The left and right travel motors M transmit rotation of the sprocket shafts 36 via the transmission gears of the transmission case 21, and the left and right crawlers 20 can be rotated to run or steer.

At the bottom of the vehicle body 7, the mowing device 6, which has the blade shaft 8 of the grass cutting blade 5 that cuts grass mounted between the left and right crawlers 20, 20, is pivotally attached to the rear ends of the parallel links 37, 38 that move up and down by link pins 39, 40 so as to be detachable. The parallel links 37, 38 are attached at their front ends to be freely rotatable around the link shaft 42 of the bearing brackets 41 provided at the front ends of both the left and right sides of the vehicle body 7, and are pivotally attached to the rear ends of the four left and right parallel links 37, 38 by link pins 39, 40. The mowing device 6 is raised and lowered while maintaining a parallel posture to the ground via the lift links 45 by the rotation of the lift arm 44, which is rotated by the expansion and contraction of the electric cylinder 43, and grass can be cut at any height.

The above-mentioned harvesting device 6 has a vertical blade shaft 8 rotatably mounted in the center, a grass cutting blade 5 attached to the lower end of the blade shaft 8, and a cutting blade 46 pivoted to the outer periphery of the grass cutting blade 5. A cutting blade pulley 9 is attached to the upper end of the blade shaft 8 above the harvesting deck 47 of the harvesting device 6, and two upper and lower counter pulleys 10 are attached to a counter shaft 49 arranged behind the cutting blade pulley 9. A V-belt 12 is wound between the lower pulley groove of the counter pulley 10 and the cutting blade pulley 9, and a tension pulley 48 is tensioned and relaxed on the rotating outer periphery of the V-belt 12 to transmit power from the counter shaft 49 to the blade shaft 8, making it possible to perform cutting. 6, a clutch arm 51 of the tension pulley 48 is pivotally mounted on a pivot shaft 50 on the upper surface of the mowing deck 47, and an operating wire 52 connected to an operating arm 53 is operated by an electric cylinder 54 to tension or release the tension pulley 48 to the V-belt 12. A brake arm 55 is rotatably provided on the upper surface of the mowing deck 47 around the cutting blade pulley 9, and engages and slides into the V-groove of the cutting blade pulley 9 to brake the rotation of the blade shaft 8. An operating wire 58 connects the electric cylinder 54 and the operating arm 57, and the electric cylinder 54 can be operated to brake and release the brake on the cutting blade pulley 9. Therefore, when the electric cylinder 54 is extended, the tension pulley 48 tensions the V-belt 12 and the brake arm 55 moves away from the V-groove portion of the blade pulley 9, and when the electric cylinder 54 is contracted, the tension pulley 48 relaxes the V-belt 12 and the brake arm 55 slides into the V-groove portion of the blade pulley 9, applying a braking force to the blade shaft 8 and quickly stopping the inertial rotation of the blade 46.

The engine base 2 has trapezoidal brackets 59 formed at the front and rear ends of the bottom to reinforce the support structure for the engine 1, etc., and the electric cylinder 19 provided between the bracket 59 and the vehicle body 7 is extended and retracted to pivot the engine base 2 around a support member 60 at the left and right center of the vehicle body 7 so that it can rotate left and right. Support metals 62 are provided at the left and right center positions of horizontal bars 61 at the front and rear of the vehicle body 7, and the support member 60 of the bracket 59 is fitted and supported between these front and rear support metals 62, 62, allowing the engine base 2 to rotate freely left and right over an appropriate angle. The left and right rotation of the engine base 2 is controlled based on the detection results of left and right inclination angle detection means LR and front and rear inclination angle detection means FB, which detect the inclination angle of the grass-cutting ground.

The output shaft 3 of the engine 1 protrudes downward from the engine base 2, and two engine pulleys 4, one above the other, are attached to the output shaft 3. An alternator 26 is disposed behind the engine 1, and a pulley 63 is attached to the shaft 26a of the alternator 26. A V-belt 64 is wound between the upper pulley groove of the engine pulley 4 and the pulley 63. When the engine 1 is started, the alternator 26 rotates, allowing the battery 25 (lithium ion battery) for driving the travel motor M to be charged. The battery 23 for starting the engine 1 is charged from a regulator provided on the engine 1. A V-belt 11 is wound between the lower pulley groove of the engine pulley 4 and the upper pulley groove of the counter pulley 10 on the harvesting deck 47, and a tension arm 66 pivoted to a tension shaft 65 in front of the engine pulley 4 is pulled by a spring 68, so that a tension pulley 67 pivoted to the tip of the tension arm 66 is constantly tensioned from the outer periphery of the V-belt 11 to transmit power.

The V-belt 11 is wound between the engine pulley 4 on the engine base 2 side, which is arranged at a distance from the front and rear of the vehicle body 7, and the counter pulley 10 on the harvesting device 6 side. When the harvesting device 6 is raised and lowered, the belt line between the engine pulley 4 and the counter pulley 10 shifts in the vertical direction. Furthermore, when the engine base 2 is tilted left and right, the engine pulley 4 tilts and the V-belt 11 becomes twisted. In grass cutting work, if the harvesting device 6 is lowered to cut the grass short, the cutting resistance increases, and if the cutting blade 46 comes into contact with soil or stones on the ground, the load on the V-belt 11 becomes even greater. When the V-belt 11, which is already under such a heavy load, is twisted due to the tilt of the engine pulley 4, the load on the V-belt 11 increases and its durability is significantly reduced. On the other hand, many general-purpose gasoline engines (wet sump type that stores oil in the crankcase) are limited to a continuous inclination angle of 25 degrees or less, and since engines limited to an inclination of 25 degrees or less cannot be used on slopes exceeding 25 degrees, it is necessary to tilt the engine 1 toward the mountain side KY of the inclined surface K so that the angle is 25 degrees or less. Some gasoline engines are dry sump type (a method in which oil is stored in a large-capacity separate tank and supplied to the engine by a pump) and can handle inclinations of 45 degrees or less, but they require a separate engine oil tank and a pump to supply oil, which are very expensive and require space to install the oil tank, so wet sump type gasoline engines are often used for grass cutting machines.

The grass cutting machine of the present invention can be displaced and tilted 20 degrees on each side in the left and right direction based on a state V in which the engine 1 is approximately vertical to the horizontal direction of the vehicle body 7 (a state in which the left and right tilt is 0 degrees), and can accommodate an inclined surface K angle of 45 degrees or less on either side, combined with a limit angle G of 25 degrees for continuous use of the engine 1. The left and right tilt angles of the engine 1 can be tilted and stopped at multiple inclination angles of 7 degrees, 14 degrees, and 20 degrees in the left and right direction based on the state V in which the engine 1 is approximately vertical to the horizontal direction of the vehicle body 7. If the front-rear tilt angle detection means FB or the left and right tilt angle detection means LR detects a tilt angle of 40 degrees, the LED lamps 69 on the upper side of the cover 29 flash, and if it detects an even steeper tilt of 45 degrees, the LED lamps 69 continue to flash and a warning buzzer sounds to alert the operator to the possibility of the vehicle body 7 tipping over. In addition, in the grass cutting machine of the present invention, when the longitudinal inclination angle detection means FB detects a 45 degree displacement inclination angle in the longitudinal direction and when the left-right inclination angle detection means LR detects a 45 degree displacement inclination angle in the left-right direction, the moving vehicle body 7 is stopped temporarily, and control is performed with consideration given to preventing overturning. In order to make the stopped vehicle body 7 move again, the forward/reverse stick 91 of the transmitter 74 is returned to the neutral position once if the longitudinal inclination angle detection means FB detects a 45 degree displacement inclination angle, and the turning stick 92 of the transmitter 74 is returned to the neutral position once if the left-right inclination angle detection means LR detects a 45 degree displacement inclination angle, and then the moving vehicle can be started again by operating it again. In FIG. 7, 70 is a recoil starter for starting the engine 1, 71 is an emergency stop switch, 72 is an hour meter, 73 is a throttle lever for adjusting the rotation speed of the engine 1, and 80 is a battery remaining amount meter.

Based on the development diagram of Figure 10, an example will be described in which the left side of the vehicle body 7 is low and in a leftward downward direction. When the vehicle body 7 is traveling laterally (in the contour direction) on the inclined surface K in a leftward downward direction, if the detection angle of the left-right inclination angle detection means LR is changing in a direction that becomes steeper, among the settings of the predetermined mountain side set angle Y for each left-right stage, the first stage predetermined mountain side set angle Y1 is set to a leftward downward 22 degrees, which is close to the 25 degrees of the continuous usable limit angle G of the engine 1, the second stage predetermined mountain side set angle Y2 is set to a leftward downward 30 degrees, and the third stage predetermined mountain side set angle Y3 is set to a leftward downward displacement inclination angle of 36 degrees. If the detected displacement angle of the left-right inclination angle detection means LR is less than 22 degrees leftward, the engine 1 is maintained in a substantially vertical state V with respect to the vehicle body 7, and when the left-right inclination angle detection means LR detects 22 degrees leftward, the engine 1 is tilted 7 degrees from the substantially vertical state V with respect to the vehicle body 7 toward the mountain side KY of the inclined surface K. When the left/right inclination angle detection means LR detects a leftward downward angle of 30 degrees at the specified mountain side set angle Y2, the engine 1 is tilted a further 7 degrees toward the mountain side KY of the inclined surface K to 14 degrees, and when the left/right inclination angle detection means LR detects a leftward downward angle of 36 degrees at the specified mountain side set angle Y3, the engine 1 is tilted a further 6 degrees toward the mountain side KY of the inclined surface K to 20 degrees (the maximum inclination angle of the engine 1).

Furthermore, when the vehicle body 7 is traveling laterally (in the contour direction) on an inclined surface K with its left side downward, for example, if the detection angle of the left-right inclination angle detection means LR changes from a left-side downward angle of 40 degrees to a gentler angle, then of the settings of the predetermined valley side set angle T for each left-side stage, the predetermined valley side set angle T3 for the third stage is set to a left-side downward angle of 34 degrees which is gentler than the predetermined mountain side set angle Y3, and similarly for the predetermined valley side set angles T2 and T1, the predetermined valley side set angle T2 for the second stage is set to a left-side downward angle of 27 degrees which is gentler than the predetermined mountain side set angle Y2, and the predetermined valley side set angle T1 for the first stage is set to a left-side downward angle of 20 degrees which is gentler than the predetermined mountain side set angle Y1. When the left-right inclination angle detection means LR detects a leftward descent of 34 degrees at the specified valley side set angle T3, the engine 1 stops at an angle tilted 6 degrees toward the valley side KT from a state inclined 20 degrees toward the mountain side KY with respect to the vehicle body 7 (the same inclination state as a state inclined 14 degrees toward the mountain side KY with respect to the vehicle body 7). When the inclination angle of the inclined surface K becomes gentler and the left-right inclination angle detection means LR detects a leftward descent of 27 degrees at the specified valley side set angle T2, the engine 1 is tilted another 7 degrees toward the valley side KT of the inclined surface K (the same inclination state as a state inclined 7 degrees toward the mountain side KY with respect to the vehicle body 7). When the inclination angle of the inclined surface K becomes gentler from this state and the left-right inclination angle detection means LR detects a leftward descent of 20 degrees at the specified valley side set angle T1, the engine 1 is tilted 7 degrees toward the valley side KT of the inclined surface K (the same state as the approximately vertical state V with respect to the vehicle body 7).

In these engine 1 tilt controls, the tilt angle at which the engine 1 starts to tilt varies depending on the angle detected by the longitudinal tilt angle detection means FB. When the lateral tilt is changing in a steeper direction, if the longitudinal tilt angle detection means FB detects a tilt angle less than a first set angle X1 (in this embodiment, the longitudinal displacement tilt angle is set to 10 degrees), the left/right increasing /front/rear gentle tilt control P1 mode is executed. In the left/right increasing gentle front/rear tilt control P1 mode, among the settings of the predetermined mountain side set angle Y for each stage in the left/right direction when traveling sideways with the vehicle body 7 in a downward leftward position on an inclined surface K, the predetermined mountain side set angle Y1 for the first stage is set to 22 degrees downward to the left, which is close to the continuous usable limit angle G of the engine 1, and until the predetermined mountain side set angle Y1 is detected to be 22 degrees downward to the left, the engine 1 maintains a substantially vertical state V (a state in which the left/right tilt angle is 0 degrees) with respect to the vehicle body 7, and when the predetermined mountain side set angle Y1 of 22 degrees downward to the left is detected, the engine 1 is tilted by 7 degrees from the 0 degree state of the substantially vertical state V toward the mountain side KY of the inclined surface K, and the predetermined mountain side set angle Y2 of 30 degrees downward to the left is set. When this is done, the engine 1 is tilted a further 7 degrees toward the mountain side KY to 14 degrees, and when the specified mountain side set angle Y3 reaches 36 degrees downward to the left, tilt control is executed to tilt the engine 1 a further 6 degrees toward the mountain side KY to 20 degrees. However, when the front-to-rear tilt angle detection means FB detects the first set angle X1 or more, a transition is made to a left-right increased front-to-rear steep tilt control Q1 mode in which, of the settings of the mountain side tilt set angle y for each stage in the left-right direction, the first stage mountain side tilt set angle y1 is set to 5 degrees downward to the left, the second stage mountain side tilt set angle y2 is set to 13 degrees downward to the left, and the third stage mountain side tilt set angle y3 is set to 18 degrees downward to the left . Therefore, when the angle detected by the left-right inclination angle detection means LR is less than 5 degrees downward to the left, the engine 1 is maintained in an approximately vertical state V with respect to the vehicle body 7, but if a downward angle of 5 degrees to the left is detected, the engine 1 is tilted 7 degrees from the approximately vertical state V toward the mountain side KY of the inclined surface K, and if the left-right inclination angle detection means LR detects a downward angle of 13 degrees to the left, the engine 1 is tilted a further 7 degrees toward the mountain side KY of the inclined surface K to 14 degrees, and if the left-right inclination angle detection means LR detects a downward angle of 18 degrees to the left, the engine 1 is tilted a further 6 degrees toward the mountain side KY of the inclined surface K to 20 degrees (the maximum inclination angle of the engine base 2), and even if the inclination angle detected by the left-right inclination angle detection means LR is a gentle angle, tilting of the engine 1 toward the mountain side KY is started, and tilt control is performed to protect the engine 1.

Similarly, when the vehicle body 7 is traveling sideways on an inclined surface K in a downward leftward state, for example, if the angle detected by the left-right inclination angle detection means LR is changing from a downward left angle of 40 degrees to a gentler direction, the longitudinal inclination angle detection means FB executes the left- right reduced longitudinal gentle inclination control P2 mode in the case of an inclination angle less than the first set angle X1 (in this embodiment, the longitudinal displacement inclination angle is set to 10 degrees), and among the settings of the predetermined valley side set angle T for each stage in the left-right direction, if the third stage predetermined valley side set angle T3 is detected as a downward left angle of 34 degrees, which is a gentler inclination angle than the predetermined mountain side set angle Y3, the engine 1 is started up to the valley side KT of the inclined surface K. Similarly, for the predetermined valley side set angles T2, T1, when the predetermined valley side set angle T2 becomes 27 degrees downward to the left and the predetermined mountain side set angle T1 becomes 20 degrees downward to the left, the engine 1 is controlled to tilt toward the valley side KT, but when the longitudinal inclination angle detection means FB detects the first set angle X1 or more, a transition is made to a left/right decreased longitudinal steep inclination control Q2 mode in which, of the settings of the valley side inclination set angle t for each stage in the left/right direction, the third stage valley side inclination set angle t3 is set to 16 degrees downward to the left, the second stage valley side inclination set angle t2 is set to 9 degrees downward to the left, and the first stage valley side inclination set angle t1 is set to 2 degrees downward to the left. Therefore, when the left-right inclination angle detection means LR detects a valley side inclination setting angle t3 of 16 degrees downward to the left, the engine 1 is tilted from the maximum left-right inclination state VM in which the engine 1 is inclined 20 degrees toward the mountain side KY of the inclined surface K relative to the vehicle body 7 to 14 degrees, which is tilted 6 degrees toward the valley side KT; when the left-right inclination angle detection means LR detects a valley side inclination setting angle t2 of 9 degrees downward to the left, the engine 1 is tilted a further 7 degrees toward the valley side KT of the inclined surface K to 7 degrees; and when the left-right inclination angle detection means LR further detects a valley side inclination setting angle t1 of 2 degrees downward to the left, the engine 1 is tilted a further 7 degrees toward the valley side KT of the inclined surface K to an approximately vertical state V (left-right inclination angle is 0 degrees).

Next, the tilting state of the engine 1 according to the change of the left-right inclination angle and the front-rear inclination angle during grass cutting work will be described. For example, when the vehicle body 7 is traveling laterally on the slope K in a left-right downward direction with the left side of the body 7 lowered, and the left-right inclination angle detection means LR detects, for example, a left-right downward inclination of 33 degrees (a left-right downward inclination in the range of 30 degrees or more of the predetermined mountain side set angle Y2 and less than 36 degrees of the predetermined mountain side set angle Y3), and the front-rear inclination angle detection means FB detects, for example, a front-rear downward inclination of 8 degrees (a front-rear downward inclination of less than 10 degrees set at the first set angle X1), the left-right increased , front-rear gentle inclination control P1 mode is executed, and the engine 1 is in a state of inclination of 14 degrees toward the mountain side KY of the slope K based on the approximately vertical state V. From this state, the left and right inclination angles become gentler while the detection angle of the front-rear inclination angle detection means FB remains in a state of less than 10 degrees downward toward the front set at the first set angle X1, and when the detection angle of the left and right inclination angle detection means LR detects a left downward angle of 27 degrees of the specified valley side set angle T2, the engine 1 tilts from a state inclined at 14 degrees toward the mountain side KY toward the valley side KT by 7 degrees (a state inclined at 7 degrees toward the mountain side KY with the approximately vertical state V as the reference), and the left and right inclination angles become further gentler, and from this state, when the detection angle of the left and right inclination angle detection means LR detects a left downward angle of 20 degrees of the specified valley side set angle T1 while the front-rear inclination angle detection means FB remains in a state of less than 10 degrees downward toward the front set at the first set angle X1, the engine 1 tilts from a state inclined at 7 degrees toward the mountain side KY with the approximately vertical state V as the reference to a tilt of 0 degrees of the approximately vertical state V. When the detection angle of the left/right inclination angle detection means LR detects a leftward downward angle of 27 degrees, which is the specified valley side set angle T2, and the engine 1 is inclined at 7 degrees toward the mountain side KY based on the approximately vertical state V, and the detection angle of the front/rear inclination angle detection means FB remains in a state where the front downward angle is less than the first set angle X1, which is the 10 degree forward downward angle, the engine 1 will not start tilting until it detects a leftward downward angle of 30 degrees, which is the specified mountain side set angle Y2.

In addition, for example, when the vehicle body 7 is traveling laterally on the slope K in a leftward downward direction with the left side of the body 7 being low, and the left/right inclination angle detection means LR detects a leftward inclination of 33 degrees (a leftward inclination of 30 degrees or more at the predetermined mountain side set angle Y2 and less than a leftward inclination of 36 degrees at the predetermined mountain side set angle Y3), and the front/rear inclination angle detection means FB detects a frontward inclination of 8 degrees (a frontward inclination of less than 10 degrees set at the first set angle X1), the engine 1 is inclined from a state in which it is inclined 14 degrees toward the mountain side KY of the slope K with respect to the substantially vertical state V, When the detection means FB reaches 10 degrees forward downward as set by the first set angle X1, the left and right tilt angle is already inclined to 13 degrees forward downward as set by the mountain side tilt set angle y2 and 18 degrees forward downward as set by the mountain side tilt set angle y3, so that the control shifts to left and right increased front and rear steep tilt control Q1, and the engine 1 is tilted from a state inclined at 14 degrees toward the mountain side KY to a state inclined at 20 degrees based on the substantially vertical state V, thereby preventing problems such as seizure and uneven wear caused by the engine 1 being inclined to the limit angle G or more. Note that, during the execution of the left and right increased front and rear gentle tilt control P1 while traveling on a left downward slope, if the first set angle X1 reaches 10 degrees forward downward, the control shifts to left and right increased front and rear steep tilt control Q1, and once the control shifts to left and right increased front and rear steep tilt control Q1, the control does not return to left and right increased front and rear gentle tilt control P1 until the detection angle of the front and rear tilt angle detection means FB detects 5 degrees forward downward as set by the second set angle X2 (in this embodiment, the front and rear displacement tilt angle is set to 5 degrees). Furthermore, while the left/right increasing front/rear gentle incline control P1 is being executed when traveling on a right downward slope, if the front downward or rear downward displacement incline angle of the first set angle X1 becomes 10 degrees or more, the control switches to the left/right increasing front/rear steep incline control Q1, and once the control switches to the left/right increasing front/rear steep incline control Q1, it does not return to the left/right increasing front/rear gentle incline control P1 until the detection angle of the front downward or rear downward displacement incline angle detection means FB detects 5 degrees which is set as the second set angle X2.

The controller 22 is provided for controlling the mowing and running of the mower, and a receiver 75 is provided in the controller 22 for receiving transmissions from the radio transmitter 74. The controller 22 also includes a left/right tilt sensor 76 for the left/right tilt angle detection means LR of the vehicle body 7, a front/rear tilt sensor 77 for the front/rear tilt angle detection means FB of the vehicle body, a temperature sensor 78 for the running motor M, an alternator temperature sensor 79, etc. (See Figure 9) The radio 74 has a signal transmission/reception antenna I, and on the top center surface is a slide switch 90 for turning the power on and off, and on both sides of this are a forward/reverse stick 91 for forward/rear running by operating it forward/rear, and a turning stick 92 for turning the direction of turning by operating it left/right. An LCD display 93 is provided on the bottom of the top surface of the radio 74, which can display the running status and working status of the mower, errors, etc. On one side of this, there is a touch sensor 94 for the LCD display 93, and in the upper center there is a speed dial 95 that can adjust the maximum speed as desired, and a cutting height dial 96 that can adjust the height at which the grass is cut as desired. On the left side, there are a cutting clutch switch 97 that turns the cutting clutch 18 on and off, and a changeover switch 98 for switching various operations and operations between automatic and manual, and on the right side, there is a start button 99 for the engine 1, an engine stop switch 100, etc.

1 Engine 2 Engine base 3 Output shaft 4 Engine pulley 5 Grass cutting blade 6 Mowing device 7 Vehicle body 8 Blade shaft 9 Mowing blade pulley 10 Counter pulley 11 V-belt 12 V-belt FB Front-rear inclination angle detection means G Limit angle H Plane K Inclined surface KY Mountain side KT Valley side LR Left-right inclination angle detection means M Travel motor P1 Left-right increase front-rear gentle inclination control P2 Left-right decrease front-rear gentle inclination control Q1 Left-right increase front-rear steep inclination control Q2 Left-right decrease front-rear steep inclination control T Predetermined valley side setting angle t Valley side inclination setting angle V Approximately vertical state VM Maximum inclination state X1 First setting angle X2 Second setting angle Y Predetermined mountain side setting angle y Mountain side inclination setting angle

Claims (6)

An engine pulley (4) is attached to an engine output shaft (3) that protrudes downward from an engine base (2) on which an engine (1) is mounted, and a mowing device (6) equipped with a grass-cutting blade (5) that rotates approximately horizontally is provided below the engine base (2) so as to be freely raised and lowered relative to a vehicle body (7). The engine pulley (4) and a counter pulley (10) provided on the mowing device (6) are disposed spaced apart in the front-to-rear direction, and a cutting blade pulley (9) that is attached to a blade shaft (8) of the grass-cutting blade (5) is disposed in the front-to-rear intermediate portion between the engine pulley (4) and the counter pulley (10). In a grass cutting machine in which a V-belt (11), (12) is used to transmit power between a lower pulley (10) and a blade pulley (9), and an engine (1) can be automatically tilted in the left-right direction of a vehicle body (7) based on the detection results of a front-rear inclination angle detection means (FB) and a left-right inclination angle detection means (LR) which detect the inclination angle of the vehicle body (7), a predetermined mountain side set angle (Y) is set within a range of left-right displacement inclination angles of at least 10 degrees, and when traveling on a flat surface (H), the engine (1) is set in a substantially vertical state (V) with respect to the horizontal direction of the vehicle body (7), and when the left-right inclination is in a state of 0 degrees or less than the predetermined mountain side set angle (Y), the inclination angle of ... 7 ), and controls the engine (1) to tilt toward the mountain side (KY) of the inclined surface (K) when a predetermined mountain side set angle (Y) is detected, and when traveling on the inclined surface (K) in the contour line direction, the predetermined mountain side set angle (Y) for tilting the engine (1) toward the mountain side (KY) of the inclined surface (K) when the angle detected by the left/right inclination angle detection means (LR) is changing in a direction to become steeper, and the predetermined valley side set angle (T) for tilting the engine (1) toward the valley side (KT) of the inclined surface (K) when the angle detected by the left/right inclination angle detection means (LR) is changing in a direction to become gentler are set to different angles, and the predetermined valley side set angle (T) is set to an angle gentler than the predetermined mountain side set angle (Y) . 2. A grass cutting machine according to claim 1, wherein the predetermined mountain side set angle (Y) is set within a range of 5 degrees below the continuous usable limit angle (G) of the engine (1). 3. The grass cutting machine according to claim 1, wherein when the longitudinal inclination angle detection means (FB) detects a displacement inclination angle less than a first set angle (X1) and the angle detected by the left/right inclination angle detection means (LR) is changing in a direction to become steeper, a left/right increasing longitudinal gentle inclination control (P1) is executed in which a predetermined mountain side set angle (Y) is set within a range of 5 degrees below a continuous usable limit angle (G) of the engine (1), and when the longitudinal inclination angle detection means (FB) detects a displacement inclination angle of the first set angle (X1) or more, if the left/right inclination angle detection means (LR) detects a displacement inclination angle of the first set angle (X1) or more, the grass cutting machine transitions to a left/right increasing longitudinal steep inclination control (Q1) in which the engine (1) is tilted toward the mountain side (KY) of the inclined surface (K) and controlled. 3. The grass cutting machine according to claim 1, wherein, when the front-rear inclination angle detection means (FB) detects a displacement inclination angle less than a first set angle (X1) and the angle detected by the left-right inclination angle detection means (LR) is changing in a gentler direction, a left-right reduced front-rear gentle inclination control (P2) is executed in which the engine (1) is tilted toward the valley side (KT) of the inclined surface (K) at a predetermined valley -side set angle (T) that is set at a tilt angle gentler than the predetermined mountain-side set angle (Y), and when the front-rear inclination angle detection means (FB) detects a displacement inclination angle equal to or greater than the first set angle (X1), the grass cutting machine is switched to a left-right reduced front-rear steep inclination control (Q2) in which the engine (1) is not tilted toward the valley side (KT) of the inclined surface (K) until the left-right inclination angle detection means (LR) detects a displacement inclination angle equal to or less than a valley-side inclination set angle ( t ) that is gentler than the predetermined valley-side set angle (T). 5. A grass cutting machine as claimed in claim 3 or 4 , characterized in that after detecting a displacement inclination angle of a first set angle (X1) or more from a state of left /right increasing front/ rear steep inclination control (P1) or left/ right decreasing front/rear steep inclination control (P2) to a state of left/right increasing front/rear steep inclination control (Q1) or left/right decreasing front/rear steep inclination control (Q2), the state of left /right increasing front/rear steep inclination control (Q1) or left/ right decreasing front/rear steep inclination control (Q2) is maintained until the front/rear inclination angle detection means (FB) detects a second set angle ( X2 ). The grass cutting machine according to claim 4 or 5, characterized in that the predetermined mountain side set angle (Y) and mountain side inclination set angle (y) at which the engine (1) begins to tilt between a substantially vertical state (V) and a maximum left and right inclination state (VM) relative to the horizontal direction of the vehicle body (7), and the predetermined valley side set angle (T ) and valley side inclination set angle (t ) are set at a plurality of inclination angle stages.

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