JP7854151B2 - Self-propelled work device - Google Patents

Description

This invention relates to a self -propelled work device.

Conventionally, lawnmowers (working devices) that autonomously travel on slopes to mow grass are known in order to reduce the burden on workers during grass cutting work on slopes. In such working devices, when traveling along a slope along contour lines, the working device's attitude angle tends to point towards the valley side due to the influence of its own weight and gravity. To prevent this from causing the device to deviate from the contour lines or to skid, a configuration is known in which the wheels of the working device are given a camber angle relative to the slope, and the wheels are positioned vertically relative to the slope, causing the wheels to bite into the slope and the working device's attitude angle to point towards the mountain side of the slope (see, for example, Patent Document 1).

Japanese Patent Publication No. 2018-174759

However, the mechanism for creating a camber angle in the wheels as described above is complex, and there was a challenge in manufacturing the mechanism for forming the camber angle. Furthermore, when a camber angle is applied to the wheels, the working device is not parallel to the inclined surface, which could cause the tip of the grass-cutting blade attached to the device to dig into the inclined surface, potentially reducing the efficiency of grass cutting.

This invention has been made in view of the above circumstances, and aims to provide a self-propelled work device that stabilizes the attitude angle of the work device and suppresses lateral slippage with a simple configuration.

To solve the above problems, the invention described in claim 1 is a self-propelled work device comprising: a main body; a running wheel supported by the main body and having a front wheel and a rear wheel ; and a work unit supported by the main body and positioned opposite to the running surface on which the running wheel runs , wherein the running wheel is capable of running on an inclined running surface and is movable in a direction intersecting the inclination direction of the inclined running surface, wherein the outrigger arm comprises: an arm supported by the main body and extending toward the running surface from between the front wheel and the rear wheel positioned on the valley side of the running surface; and an auxiliary wheel provided on the arm and erected toward the running surface on the valley side of the running surface, further on the front side of the running surface than the front wheel and the rear wheel positioned on the valley side of the running surface, and driven in accordance with the movement of the self-propelled work device , wherein the outrigger arm further comprises a length adjustment mechanism that can adjust the length of the arm so that when the auxiliary wheel is in contact with the inclined running surface, the central axis of the auxiliary wheel in a front view is perpendicular to the horizontal plane or inclined toward the mountain side of the inclined running surface .

In a self-propelled work device , auxiliary wheels are positioned vertically on the valley side of the running surface, so that the front and rear wheels are in contact with the running surface at approximately a right angle. As a result, the camber effect of the auxiliary wheels stabilizes the attitude angle of the self-propelled work device on the running surface, allowing it to travel along contour lines and suppressing lateral slippage of the self-propelled work device.

Furthermore, the self-propelled work device , equipped with a length adjustment mechanism, ensures that the auxiliary wheels are securely positioned on the running surface, thereby achieving a camber effect. In addition, lengthening the arm section increases the load distribution on the front and rear wheels on the uphill side, suppressing lateral slippage.

The invention described in claim 2 is characterized by comprising a first angle adjustment mechanism for adjusting at least one of the inclination angle of the arm portion in a plan view and the inclination angle of the main body portion with respect to a front view.

In self-propelled work devices , the variable angle of the arm allows for the placement of the arm and auxiliary wheels while considering the configuration of the front and rear wheels. Therefore, the camber effect of the auxiliary wheels can be utilized regardless of the configuration of the front and rear wheels or the unevenness of the running surface.

The invention described in claim 3 is characterized by comprising a second angle adjustment mechanism that adjusts at least one of the planar inclination angle of the auxiliary wheel and the inclination angle of the main body with respect to the front view.

The self-propelled work device allows for the adjustment of the angle of the auxiliary wheels, enabling the auxiliary wheels to be positioned stably regardless of the unevenness of the running surface.

In the invention described in claim 4 , the auxiliary wheel is characterized in that it has a hard edge portion that protrudes outward from the rotating surface that rotates on the running surface, and that becomes embedded in the running surface when the main body moves in a direction intersecting the inclination direction of the running surface.

By incorporating an edge section, the self-propelled work device can increase the amount the auxiliary wheels bite into the running surface, further improving the effect of suppressing lateral slippage of the self-propelled work device.

The invention described in claim 5 is characterized in that a plurality of auxiliary wheels are arranged between the front wheel and the rear wheel, which are at least located on the valley side of the running surface.

By equipping a self-propelled work device with multiple auxiliary wheels, the camber effect of the auxiliary wheels can be increased, further improving the lateral slip suppression effect of the self-propelled work device.

The invention described in claim 6 is characterized in that a plurality of arm portions are arranged between the front wheel and the rear wheel, which are at least located on the valley side of the running surface.

The self-propelled work device , with its multiple arm sections, allows for a simplified configuration of the outrigger arms, even when equipped with multiple auxiliary wheels.

The invention described in claim 7 is characterized in that the work unit comprises a grass cutter positioned opposite the running surface.

The self-propelled work device, equipped with outrigger arms, allows the working unit (the mower) to be positioned parallel to the running surface, enabling efficient grass cutting without the mower blades contacting the running surface.

According to this invention, it is possible to provide an outrigger arm and a self-propelled work device equipped with an outrigger arm that stabilize the posture angle of the work device and suppress lateral slippage with a simple configuration.

This is a perspective view showing a self-propelled work device according to the first embodiment of the present invention. This is a top view showing a self-propelled work device according to the first embodiment of the present invention. This is a front view showing a self-propelled work device when installed on a running surface according to the first embodiment of the present invention. This is an explanatory diagram showing a method for moving a self-propelled work device according to the first embodiment of the present invention. This graph shows the relationship between the length of the outrigger arm of a self-propelled work device according to the first embodiment of the present invention and the amount of lateral slip of the self-propelled work device. This is a perspective view showing a self-propelled work device according to a second embodiment of the present invention. This graph shows the relationship between the length of the outrigger arm of a self-propelled work device according to the second embodiment of the present invention and the amount of lateral slip of the self-propelled work device. This is a perspective view of a self-propelled work device according to a third embodiment of the present invention. This is a top view of a self-propelled work device according to a third embodiment of the present invention. This graph shows the relationship between the number of auxiliary wheels of a self-propelled work device according to the third embodiment of the present invention and the amount of lateral slippage of the self-propelled work device.

The following describes an outrigger arm and a self-propelled work device equipped with the outrigger arm according to an embodiment of the present invention, based on Figures 1 to 10. In the drawings, the front-rear direction of the self-propelled work device is denoted as the X direction, the width direction as the Y direction, and the height direction as the Z direction.

(First Embodiment)
The first embodiment of the present invention will be described below with reference to Figures 1 to 5.
As shown in Figures 1 and 2, the self-propelled work device 1 (hereinafter referred to as "work device 1") comprises a main body 11, travel wheels 12, a travel drive unit 13, and outrigger arms 14. As shown in Figure 3, the work device 1 travels on a travel surface F having an inclination angle α. The travel surface F may be, for example, a sloping levee between terraced rice paddies or rice fields, or a bank or embankment of a riverbed. In the following description, the lower side of the inclination on the travel surface F will be referred to as the valley side, and the upper side of the inclination will be referred to as the mountain side.

The main body 11 includes a work unit 110 that performs work while the work device 1 is in motion. The work unit 110 includes a known grass cutter 111 positioned approximately in the center of the work unit 110 in the X and Y directions, facing the travel surface F. The work device 1 cuts the grass growing on the travel surface F using the grass cutter 111 while traveling on the travel surface F.

The running wheels 12 comprise front wheels 121a and 121b supported at both ends in the Z direction of the front end of the main body 11, and rear wheels 122a and 122b supported at both ends in the Z direction of the rear end of the main body 11. The working device 1 moves forward or backward in the X direction by driving the running wheels 12 with the running drive unit 13. The running wheels 12 are, for example, known rubber tires.

The drive unit 13 is mounted on the main body 11. The drive unit 13 comprises a first power supply unit 131 for driving the drive wheels 12 and a second power supply unit 132 for driving the lawnmower 111.

The outrigger arm 14 comprises an arm portion 141, a support portion 142, and an auxiliary wheel 143.

The arm portion 141 has a rectangular parallelepiped shape with one direction being longer when viewed from above. The arm portion 141 is connected to the support portion 142 approximately in the middle of its longitudinal direction and supported by the main body portion 11. When the work device 1 is positioned on the running surface F, the arm portion 141 extends from between the front wheel 121a and the rear wheel 122a, which are positioned on the valley side of the running surface F, toward the valley side of the running surface F.

The arm portion 141 is equipped with a length adjustment mechanism 144 for adjusting its longitudinal length L1. The length adjustment mechanism 144 may be a mechanism that automatically adjusts the length by driving a power source such as a motor, as in a known linear actuator, or it may be a mechanism that adjusts the length manually, as in a known ball screw.

The support portion 142 is placed between the front wheel 121a and the rear wheel 122a on the main body portion 11 and supports the arm portion 141.

The arm section 141 includes a third power supply unit 145 that drives the length adjustment mechanism 144. The third power supply unit 145 may be built into the arm section 141 or into the support section 142. Alternatively, the length adjustment mechanism 144 may be driven by the first power supply unit 131 or the second power supply unit 132.

The auxiliary wheels 143 are mounted on the arm portion and, when the work device 1 moves in a direction intersecting the inclination direction of the running surface F, they make contact with the running surface F on the valley side of the running surface F, closer to the valley side than the front wheels 121a and rear wheels 122a, which are positioned on the valley side of the running surface F, and are driven in accordance with the movement of the work device 1. The auxiliary wheels 143 are known rubber tires, similar to those of the running wheels 12.

The configuration for driving the auxiliary wheels 143 may be one where it is connected to either the first power supply unit 131 or the second power supply unit 132, or a power supply unit for driving the auxiliary wheels 143 may be provided in the driving unit 13.

The auxiliary wheel 143 is rotatably connected to the valley-side tip 141a of the arm portion 141. The auxiliary wheel 143 may be configured to control its rotation using a control motor that adjusts the rotation speed on the outrigger arm 14, or it may be provided as a passive mechanism that rotates in accordance with the rotation of the running wheel 12. The auxiliary wheel 143 may also be a wheel that rotates without power due to the frictional force with the ground when the work device 1 is moved.

The working device 1 may further include a mechanism for adjusting the orientation of the running wheels 12 and auxiliary wheels 143 in a plan view, thereby changing the direction of movement of the working device 1. After the working device 1 has traveled on the running surface F in one direction, the user may directly carry and move it to the uphill or downhill side of the running surface F.

The work device 1 may further include a housing that covers the work section 110 from above, without affecting the movement of the work device 1 or the driving of the arm section 141 and the brush cutter 111.

The method for mowing grass on the travel surface F using the work device 1 will be explained. As shown in Figure 4, the work device 1 moves in a direction perpendicular to the inclination direction of the travel surface F when viewed from above during operation.

The work device 1 enters the travel surface F from the mountain side, and as shown in Figures 3 and 4, positions the arm portion 141 toward the valley side, with the front wheels 121a and rear wheels 122a facing the direction of travel of the work device 1.

The length adjustment mechanism 144 is driven to adjust the longitudinal length L1 of the arm portion 141, causing the mountain-side surface 143a of the lower end of the auxiliary wheel 143 to make contact with the running surface F. At this time, the auxiliary wheel 143 is positioned either approximately perpendicular to the reference surface F1 (horizontal plane) of the running surface F, or tilted toward the mountain side (tilted to the left in Figure 3).

In the above state, the grass cutter 111 is driven along the contour lines, and the work device 1 is advanced while cutting the grass on the travel surface F. After completing the forward movement, the work device 1 is moved to the valley side, and the grass cutting work is carried out to the lower end of the travel surface F using the same procedure. The movement of the work device 1 may also be started from the valley side of the travel surface F. The movement of the work device 1 may be remotely controlled or autonomously driven.

Next, the operation and effects of the outrigger arm 14 and work device 1 according to the above-described embodiment of the present invention will be explained with reference to the drawings.

As shown in Figures 1 to 4, by operating the outrigger arm 14, the mountain-side surface 143a of the auxiliary wheel 143 is driven into the running surface F, and the auxiliary wheel 143 is mounted so that it is approximately perpendicular to the reference plane F1 of the running surface F or inclined toward the mountain side. At this time, as shown in Figure 3, the axis L2 of the auxiliary wheel 143 in a front view is inclined by a camber angle β with respect to a virtual line L3 perpendicular to the running surface F. In the above state, the front wheels 121a, 121b and rear wheels 122a, 122b of the working device 1 are erected so that they are approximately perpendicular to the running surface F or inclined toward the mountain side. The working device 1 is supported by the auxiliary wheel 143 in an inclined state with respect to the running surface F. When the working device 1 is driven in this state, the working device 1 is positioned without sliding laterally toward the valley side of the running surface F due to the driving surface 143a of the auxiliary wheel 143 being driven into the ground and the camber angle β of the auxiliary wheel 143. Furthermore, when the work device 1 is driven with the auxiliary wheels 143 mounted so as to be inclined toward the mountain side of the running surface F, the front wheels 121a and rear wheels 122a on the valley side will spin freely due to the camber angle β of the auxiliary wheels 143, but will not slip sideways toward the valley side. Hereafter, the amount of displacement of the work device 1 toward the valley side relative to the running surface F will simply be referred to as "sideways slip amount".

With the above configuration, the outrigger arm 14 can maintain a state in which the running wheels 12 are erected so as to be approximately perpendicular to the reference plane F1 or inclined towards the uphill side, by tilting the auxiliary wheels 143 by a camber angle β on the running surface F. With this configuration, the posture angle of the work device 1 is horizontal to the running surface F or directed towards the uphill side of the running surface F, increasing the load acting on the front wheels 121b and rear wheels 122b on the uphill side of the running surface F. As a result, the work device 1 can be stably positioned on the inclined running surface F, the amount of lateral slippage towards the downhill side of the running surface F is suppressed, and the work device 1 can stably travel along the running surface F in line with the contour lines.

The outrigger arm 14 allows for adjustment of the length L1 of the arm portion 141 using the length adjustment mechanism 144. This ensures that the auxiliary wheels 143 are positioned approximately perpendicular to the reference plane F1 of the running surface F, or tilted towards the mountain side, thereby enabling the camber effect of the auxiliary wheels 143 to be achieved.

The outrigger arm 14, by increasing the length L1 of the arm portion 141 using the length adjustment mechanism 144, increases the load acting on the front wheel 121b and rear wheel 122b on the mountain side of the work device 1, thereby suppressing lateral slippage of the work device 1. For example, as shown in Figure 5, increasing the length of the arm portion 141 reduces the amount of lateral slippage of the work device 1. In Figure 5, the dashed line L4 indicates the lower limit of the amount of lateral slippage of the work device 1 when the work device 1 is driven on the running surface F without the outrigger arm 14 and with the running wheels 12 tilted by a camber angle β. From the amount of lateral slippage of the work device 1 in this embodiment and the dashed line L4, it can be seen that by arranging the auxiliary wheels 143 with the outrigger arm 14 in the above configuration, lateral slippage of the work device 1 can be reliably suppressed.

The outrigger arm 14 reduces the amount of lateral slippage of the work device 1 by increasing the rotational speed of the auxiliary wheels 143. In other words, the outrigger arm 14 can suppress the amount of lateral slippage of the work device 1 not only through the effect of the engagement of the mountain-side surface 143a of the auxiliary wheels 143 and the camber angle β of the auxiliary wheels 143, but also by increasing the rotational speed of the auxiliary wheels 143.

According to the work device 1, the above effect is achieved by attaching the outrigger arm 14 to the main body 11. Therefore, by attaching the outrigger arm 14 to an existing work device, even an existing work device that slides sideways can be made to move forward along the contour lines of an inclined travel surface F. Furthermore, since the outrigger arm 14 can be attached to and used with various types of work devices, it offers excellent versatility.

The work device 1, using the outrigger arms 14, allows the travel wheels 12 to be positioned approximately perpendicular to the travel surface F or tilted towards the mountain side, without requiring a camber angle on the travel wheels 12. Therefore, efficient grass cutting can be performed without contact between the blades and other components of the grass cutter 111 and the travel surface F.

(Second Embodiment)
A second embodiment of the present invention will be described below with reference to Figures 6 and 7. In the following description, components that are common to those already described will be denoted by the same reference numerals, and redundant explanations will be omitted.

As shown in Figure 6, the auxiliary wheel 143 is made of a known metal material, and multiple edge portions 143c are formed at regular intervals in the rotational direction on the rotating surface 143b that rotates on the running surface F.

The rotating surface 143b of the auxiliary wheel 143 is composed of a flat surface, and the auxiliary wheel 143 is formed in a rectangular shape when viewed from the front. Due to this configuration, the mountain-side surface 143a of the auxiliary wheel 143 that contacts the running surface F extends approximately perpendicular to or inclined toward the mountain side with respect to the reference surface F1 of the running surface F. Because of the rectangular shape of the auxiliary wheel 143 when viewed from the front, the mountain-side surface 143a of the auxiliary wheel 143 bites deeper into the running surface F than the auxiliary wheel 143 according to the first embodiment.

The edge portion 143c is a rigid projection that protrudes outward and can be embedded in the running surface F when the work device 1 moves along the running surface F. The material of the edge portion 143c may be a known metal material or a rigid plastic material such as FRP.

The edge portion 143c may be a straight line extending in a direction perpendicular to the rotation direction of the rotating surface 143b, or it may be formed in a V-shape extending upward in the Z direction.

With the above configuration, the outrigger arm 14 can further dig the auxiliary wheel 143 into the running surface F via the mountain-side surface 143a, embedding it in the ground, thereby further improving the anti-skid effect of the work device 1. For example, as shown in Figures 5 and 7, by providing the auxiliary wheel 143 with an edge portion 143c, the amount of skidding of the work device 1 can be suppressed more effectively than with an auxiliary wheel 143 without an edge portion 143c.

The edge portion 143c should be designed to allow the auxiliary wheel 143 to bite into the running surface F, thereby suppressing the amount of lateral slippage of the work device 1. The edge portion 143c may also have a wing-like or paddle-like shape, for example, by attaching rubber material to the rotating surface 143b, thereby propelling the auxiliary wheel 143 without generating resistance in its direction of travel.

The outrigger arm 14, equipped with an edge portion 143c, allows the mountain-side surface 143a of the auxiliary wheel 143 to easily bite into the running surface F when the working device 1 vibrates due to the crank's vibration mechanism while in operation. Therefore, lateral slippage of the working device 1 can be easily suppressed even while it is in operation.

(Third Embodiment)
A third embodiment of the present invention will be described below with reference to Figures 8 to 10. In the following description, components that are common to those already described will be denoted by the same reference numerals, and redundant explanations will be omitted.

As shown in Figures 8 and 9, the working device 1 is equipped with two outrigger arms 14a and 14b between the front wheel 121a and the rear wheel 122b. The outrigger arms 14a and 14b have the same configuration.

With the above configuration, the outrigger arms 14a and 14b have multiple contact points with the running surface F, each with a camber angle β, due to the two auxiliary wheels 143, 143. This configuration allows the lateral slip suppression effect of the work device 1 due to the camber angle β to be evenly distributed in the X direction, further suppressing the amount of lateral slip of the work device 1. For example, as shown in Figure 10, when there are two auxiliary wheels 143, lateral slip of the work device 1 is almost nonexistent.

The outrigger arms 14a and 14b have multiple contact points between the auxiliary wheels 143 and the running surface F. This results in multiple axis points in a plan view relative to the running surface F, preventing deviations in the direction of movement during travel, bringing the travel direction of the work device 1 closer to one direction (straight line), and further stabilizing the travel.

Furthermore, the provision of outrigger arms 14a and 14b ensures that each auxiliary wheel 143 can be reliably positioned at the desired angle, even when the length of each arm portion 141 required to make contact with the running surface F differs, for example, when the running surface F has irregularities.

The embodiments of the outrigger arm and the self-propelled work device equipped with the outrigger arm according to the present invention have been described above. However, the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention.

The outrigger arm 14 may be configured to include at least one of the following: an angle adjustment mechanism for adjusting the tilt angle of the arm portion 141 in a plan view with respect to the Y direction, and an angle adjustment mechanism for adjusting the tilt angle of the arm portion 141 in a front view with respect to the Y direction. By configuring the arm portion to have a variable angle, the arm portion and auxiliary wheels can be positioned considering the configuration of the front and rear wheels, and the camber effect of the auxiliary wheels can be achieved regardless of the configuration of the front and rear wheels.

The outrigger arm 14 may include at least one of the following: an angle adjustment mechanism for adjusting the tilt angle of the auxiliary wheel 143 in a plan view with respect to the Y direction, and an angle adjustment mechanism for adjusting the tilt angle of the auxiliary wheel 143 in a front view with respect to the Y direction. By configuring the angle of the auxiliary wheel 143 to be variable, the auxiliary wheel 143 can be stably erected without being affected by irregularities on the running surface F.

Furthermore, the outrigger arm 14 may be configured to include either an angle adjustment mechanism for the arm portion 141 or an angle adjustment mechanism for the auxiliary wheel 143.

The working device 1 according to each of the above embodiments is equipped with four wheels: left and right front wheels 121a, 121b and left and right rear wheels 122a, 122b. However, it may also be configured as a three-wheeled device by omitting, for example, the front wheel 121a or rear wheel 122a located on the valley side of the running surface F.

The work device 1 according to the first and second embodiments described above is equipped with one outrigger arm 14, and the work device 1 according to the third embodiment is equipped with two outrigger arms 14a and 14b. However, the work device 1 may also be configured to be equipped with three or more outrigger arms 14.

In each of the above embodiments, the auxiliary wheel 143 is provided as a tire-shaped wheel, but it may also be configured in a way other than a wheel, for example, as a known crawler (caterpillar).

In the third embodiment described above, auxiliary wheels 143 are connected to two arm sections 141, 141, but the configuration is not limited to the above. For example, the configuration of the outrigger arm 14 may be simplified by connecting multiple auxiliary wheels 143 to a single arm section 141.

The outrigger arms 14 in each of the above embodiments are provided on a work device 1 equipped with a brush cutter 111, but they may also be provided on work devices that travel on slopes other than those described above. For example, they may be provided on a slope cleaning device or on a space exploration robot that traverses slopes made of soft ground such as the lunar surface.

1. Self-propelled work device (work device)
11 Main body 12 Driving wheels 14, 14a, 14b Outrigger arms 110 Working section 111 Brush cutter 121a, 121b Front wheels 122a, 122b Rear wheels 141 Arm section 143 Auxiliary wheels 143c Edge section 144 Length adjustment mechanism F Driving surface

Claims (7)

The main body and
Supported by the main body, the running wheels include front and rear wheels,
A working section supported by the main body and positioned opposite the running surface on which the running wheels travel,
A self-propelled work device comprising , wherein the traveling wheels are capable of traveling on an inclined traveling surface, and the device is capable of moving in a direction intersecting the inclination direction of the inclined traveling surface,
Supported by the main body, an arm portion extends from between the front wheel and the rear wheel, which are positioned on the valley side of the running surface, toward the running surface,
Auxiliary wheels are provided on the arm portion and are erected on the running surface at a point on the running surface side of the running surface that is closer to the running surface than the front wheels and rear wheels which are positioned on the running surface side, and are driven in accordance with the movement of the self-propelled work device.
Equipped with outrigger arms ,
The outrigger arm further includes a length adjustment mechanism that allows adjustment of the length of the arm portion so that, when the auxiliary wheel is in contact with the inclined running surface, the central axis of the auxiliary wheel in a front view is perpendicular to the horizontal plane or inclined toward the uphill side of the inclined running surface.
Self-propelled work device . The device includes a first angle adjustment mechanism for adjusting at least one of the inclination angle of the arm portion in a plan view and the inclination angle of the main body portion with respect to a front view.
The self-propelled work device according to claim 1. The device is equipped with a second angle adjustment mechanism that adjusts at least one of the inclination angle of the auxiliary wheel in a plan view and the inclination angle of the main body with respect to a front view.
A self-propelled work device according to claim 1 or 2 . The auxiliary wheel has a hard edge portion that protrudes outward from the rotating surface that rotates on the running surface, and which becomes embedded in the running surface when the main body moves in a direction intersecting the inclination direction of the running surface.
A self-propelled work device according to any one of claims 1 to 3 . The auxiliary wheels are arranged in multiple locations between the front wheel and the rear wheel, which are positioned at least on the valley side of the running surface.
A self-propelled work device according to any one of claims 1 to 4 . The aforementioned arm portions are arranged in multiples between the front wheel and the rear wheel, which are positioned at least on the valley side of the running surface.
A self-propelled work device according to any one of claims 1 to 5 . The work unit includes a grass cutter positioned opposite the running surface.
A self-propelled work device according to any one of claims 1 to 6 .