JP2567508B2 - Slewing device for work vehicles for lawn mowing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a descending state in which a traveling device, which is located on the turning center side of a plurality of traveling devices, descends so as to float,
An elevating type grounding body that is movable up and down to rise so as to ground the traveling device and that forms the turning center in the descending state is provided on the vehicle body, and at least the grounding type grounding body of the elevating type grounding body is provided. The present invention relates to a turning device for a work vehicle for lawn mowing, the portion of which is rotatable about a longitudinal axis with respect to the vehicle body.

[Prior Art] In addition to providing an elevating type grounding body on the vehicle body to levitate the traveling device located on the turning center side of the plurality of traveling devices,
A technology in which the grounding part of the lift-type grounding body is configured to be rotatable around the longitudinal axis with respect to the vehicle body, and the lifting center is formed by the lifting-type grounding body in which the traveling device on the turning center side is levitated to turn the vehicle body. As a conventional example, as described in, for example, JP-A-48-35528, in plan view, a quadrangle connecting the ground portions of the four front traveling devices and the two rear traveling devices and the four traveling devices. It has been proposed that an elevating type grounding body is arranged inside and at a substantially central position between the front traveling device and the rear traveling device.

[Problems to be Solved by the Invention]

According to the above-mentioned conventional technique, since the grounding portion of the lifting grounding body is configured to be rotatable around the longitudinal axis with respect to the vehicle body,
It is less likely that the grounding part will rub against the grounding surface while turning the vehicle,
When seen in a plan view, the elevating grounding body is arranged at a substantially central position between the front traveling device and the rear traveling device, which is close to the vehicle body center of gravity. The supporting load of the vehicle body by the type grounding body becomes large and the grounding load of the traveling device becomes small, so that the traveling device easily slips and it is difficult to efficiently turn.

In addition, since the lifting grounding body is placed inside the quadrangle that connects the grounding parts of the four traveling devices, if the vehicle body center of gravity changes due to the difference in the riding position of passengers, the lifting grounding body will levitate. There is also a possibility that the traveling device to be used may change and it may be difficult to turn the vehicle body.

Therefore, when such a conventional turning device is provided in a work vehicle for lawn mowing, there is a problem that the lawn surface is rubbed by the slip of the traveling device and the lawn surface is easily damaged, and the efficiency of lawn mowing work is improved. There is a problem of easy deterioration.

The present invention has been made in view of the above circumstances,
When installing a swivel device on a lawn mowing work vehicle, by devising the arrangement of multiple traveling devices and elevating type grounding bodies, while improving the efficiency of lawn mowing work, damage to the grass surface due to turning of the vehicle body The purpose is to be able to suppress.

[Means for solving the problem]

In order to achieve the above object, a characteristic configuration of a turning device for a lawn mowing work vehicle according to the present invention is such that the plurality of traveling devices are provided with one front wheel for steering and two rear wheels for driving left and right. And wherein the elevating and lowering grounding body is located between the two rear wheels in a position adjacent to a lateral side of the rear wheel to be elevated and lowered so as to elevate and lower one of the two rear wheels, and , Located at a position rearward of the rotation axis of the two rear wheels.

[Work]

A plurality of traveling devices are configured by providing one front wheel for steering and two rear wheels for driving, and between two rear wheels such that one of the two rear wheels is raised and lowered. Since the elevating type grounding body is arranged at a position close to the lateral side of the rear wheel to be raised and lowered, there is little possibility that the elevating type grounding body will collide with other objects and be damaged during the reverse drive.

Also, since the lifting type grounding body is arranged at a position rearward of the rotation axis of the two rear wheels between the two rear wheels, when the lifting type grounding body is lowered, the lifting type grounding body is lowered. The vehicle body is always supported by three front wheels for steering and one rear wheel for driving, and the vehicle can be reliably turned by steering the front wheels and driving the rear wheels.

In particular, since the ground load of the front wheels and the rear wheels can be increased, it is easy to efficiently turn the traveling device in a state where the traveling device is unlikely to slip.

That is, when the traveling device on the turning center side is levitated by the elevating grounding body, the weight of the vehicle body is divided and supported by three locations, one front wheel, one rear wheel, and the elevating grounding body. As the grounding body is located closer to the center of gravity of the vehicle, the supporting load by the lifting grounding body increases and the supporting load by the front wheels and the rear wheels decreases. Since the lift-type grounding body is arranged on the rear side at a position far from the center of gravity of the vehicle, the support load by the lift-type grounding body is reduced and the support load by the front wheels and the rear wheels is increased. It can be increased.

〔The invention's effect〕

Therefore, while preventing damage to the lifting grounding body, when the traveling device on the turning center side is levitated by the lifting grounding body,
Since the vehicle can be reliably turned by a traveling device with a large ground load, the efficiency of lawn mowing work can be improved and the slip on the turf surface of the traveling device accompanying the turning of the vehicle can be reduced. It is possible to suppress damage to the turf surface due to the turning of the.

〔Example〕

Hereinafter, an embodiment in the case where the present invention is applied to a small work vehicle for lawn mowing will be described with reference to the drawings.

As shown in FIGS. 3 and 4, a single front wheel (1F) steered by an electric motor (M ₁ ) is attached to the front part of the vehicle body (V), and the rear part of the vehicle body (V) is attached. A pair of left and right driving rear wheels (1L) and (1R) are attached to the. That is, the single front wheel (1F) and a pair of left and right driving rear wheels (1F)
L) and (1R) correspond to multiple traveling devices.

A rotary blade (2) for lawn mowing, which is rotationally driven by the engine (E), is attached to the lower center of the vehicle body (V). Although not described in detail, the engine (E)
Will also be used as a drive source for the pair of left and right drive rear wheels (1L), (1R). Further, the pair of left and right driving rear wheels (1L) and (1R) are not provided with a differential device, and are driven to rotate left and right simultaneously. Further, a transmission is not provided, and only forward / backward switching and stop operation can be switched. Therefore, the vehicle speed is the engine (E)
It will be adjusted by increasing or decreasing the number of rotations.

Three steering control sensors (S ₁ ), (S ₂ ), (S) for steering the front wheel (1F) based on the presence or absence of uncut grass on the front of the vehicle body (V). ₃ ) are mounted side by side in the lateral direction of the vehicle body. However, the left and right sensors (S ₁ ) and (S ₃ ) are located behind the front wheel (1F), and the center sensor (S ₂ ) is located ahead of the front wheel (1F). Has been done.

The steering control sensors (S ₁ ), (S ₂ ), and (S ₃ ) will be described below. As shown in FIG. 5, they are so-called photointerrupter-type sensors. Based on whether or not the light transmitted between the light source and the light receiver, which are arranged facing each other with a gap in the direction, is blocked by the uncut grass, the place where the sensor is attached is the uncut land (A). It is possible to discriminate whether there is an existing cut land (B). However, since the detection signals of the steering control sensors (S ₁ ), (S ₂ ), and (S ₃ ) are intermittent depending on the density of the grass, for example, processing such as integration of the detection signals By performing the above, the binary information indicating only the state of either the uncut land (A) or the already cut land (B) is converted.

Further, three sensors are arranged in the lateral direction of the vehicle body because the boundary (L) between the uncut land (A) and the already cut land (B).
In order to automatically travel along the boundary (see FIG. 6), it is determined which of the left and right directions is deviated from the boundary, or when the vehicle body (V) is automatically traveled, the end of the work stroke is This is so that it can be determined whether or not it has reached.

If the explanation is added, as shown in FIG. 6, the lawnmower work vehicle has an uncut land (A) surrounded by the already cut land (B) as a work range, and the uncut land (A). ) And the already cut ground (B) along the boundary (L) from one end side to the other end side of the work site, and as it reaches the end, it turns to the uncut side and adjoins it. By repeating the reverse of the work process of (1) to perform so-called reciprocal traveling, the lawn mowing work within a predetermined range is automatically performed.

In other words, if the sensor located on the cut side out of the _three steering control sensors (S ₁ ), (S ₂ ), and (S ₃ ) arranged in the vehicle width direction detects the uncut area (A). By steering to the already-mowed side, and when the central sensor detects the already-mowed land (B), it steers to the unmowed side, so that the three steering control sensors (S ₁ arranged in the lateral direction of the vehicle body). ), (S ₂ ) and (S ₃ ), only one sensor at the end located on the side of the cut ground detects the cut ground (B), and the other two sensors are not cut. The state where the ground (A) is detected, that is, the vehicle body (V)
The vehicle automatically travels while maintaining the state of being properly along the boundary (L) between the uncut land (A) and the already cut land (B).

Also, the boundary (L) between the uncut land (A) and the already cut land (B)
When the vehicle travels from one end side to the other end side of the work range along the line, when the end of the work range is reached, the surroundings become the already-cut land (B). Therefore, the three steering control sensors ( All of S ₁ ), (S ₂ ), and (S ₃ ) will detect the cut land (B). Therefore, when all the three steering control sensors (S ₁ ), (S ₂ ), and (S ₃ ) detect the cut land (B), it is determined that the end of one work stroke has been reached. In order to move to the next adjacent work stroke, it is turned to the uncut land side.

By the way, when reaching the end of the work stroke and turning toward the next work stroke, the driving rear wheel on the turning center side is levitated and only the driving rear wheel on the outside of the turning is turned on. is there.

To add a further explanation, as shown in FIGS. 1 to 3, the left and right pair of driving rear wheels (1L), (1R) inside the vehicle body,
In other words, between the left and right rear wheels (1L) and (1R), the two rear wheels (1L) and (1R) are adjacent to the side of the rear wheel (1L or 1R) to be raised and lowered. At the rear side of the axis of rotation of, the one of the two rear wheels (1L) and (1R), which is located on the turning center side, descends so as to levitate, and the rear wheel An elevating type grounding body (3) is attached, which can be raised and lowered so as to rise so as to come into contact with the ground, and which forms a turning center in the lowered state. However, there are two lifting and lowering type grounding bodies (3), one for turning right and the other for turning left, and either one is used depending on the turning direction.

The two left and right elevating grounding bodies (3) have the same structure on the left and right, and the left side structure will be described below.

As shown in FIG. 1, a bolt portion (4) rotatably mounted on a vehicle body (V) about a longitudinal axis and an externally fitted bite of the bolt portion (4), V) a nut part (5) that is moved up and down, and the nut part (5)
On the other hand, the grounding part (6) is attached to the lower end of the nut part (5) so as to be rotatable around the longitudinal axis. In the figure, (7) is a pin for preventing the nut (5) from rotating, and although not described in detail, the fixing member (8) on the vehicle body (V) side
On the other hand, the nut portion (5) is restricted only in rotation about the axis of the vertical axis, and is locked in a vertically movable state.
Further, (9) is a bearing for reducing sliding resistance between the nut portion (5) and the grounding portion (6).

Although not described in detail, the gear (10) attached to the tip of the nut portion (5) is driven in the forward and reverse directions by an actuator (not shown) such as an electric motor, so that the nut portion (5) Since the grounding portion (6) attached to it is moved up and down, it is possible to switch between a state in which the rear wheel outside the grounding body (3) is in contact with the vehicle body (V) and a state in which it is raised. is there.

A control configuration for automatically traveling the work vehicle will be described. As shown in FIG. 7, information on the three steering control sensors (S ₁ ), (S ₂ ), and (S ₃ ) is used. Based on the steering control means for controlling the steering by controlling the differential of the steering electric motor (M ₁ ), the three steering control sensors (S ₁ ), (S ₂ ), Based on the information in (S ₃ ), it is determined whether or not the end of the work stroke has been reached, and power transmission between the engine (E) and the drive rear wheels (1L), (1R) is turned on and off. A control device using a microcomputer, which constitutes a traveling control means for controlling the operation of a clutch actuator (11) for operating a clutch (not shown) and an actuator (M ₂ ) for raising and lowering the grounding body (3). (12) is provided.

Next, based on the flowchart shown in FIG. 8, the turning process for reaching the end of the work stroke and turning toward the next work stroke will be described.

The three steering control sensors (S ₁ ), (S ₂ ), (S ₃ ).
When it is determined that all of the trees have reached the end of one work stroke by detecting the cut land, the vehicle temporarily stops traveling.

Then, one of the two grounding bodies (3), which is on the inside of the turn, is lowered to raise the driving rear wheel on the inside of the turn (see FIG. 2).

Next, the front wheel (1F) is steered in the turning direction at the maximum steering amount to start driving the rear wheels (1L), (1R) to turn the grounded body (3) on the grounded side. As a center, the vehicle body (V) is turned 180 degrees to the next work stroke side, that is, to the uncut land side and stopped. Whether or not the vehicle body (V) has turned 180 degrees is determined based on the driving time of the rear wheels (1L) and (1R), for example.

When the vehicle body (V) turns 180 degrees and stops, the grounded grounding body (3) is lifted to move the pair of left and right driving rear wheels (1).
Both L) and (1R) are returned to the grounded state, the processing for turning is completed, and the traveling for the next work stroke is started.

[Other Embodiments] In the above embodiment, the drive rear wheels (1L) and (1R) are not provided with a differential device, so that the other side, which is grounded, is driven to turn even if one of them is levitated. Although the case where it is possible to do so is illustrated, for example, when a differential device is provided, a brake is provided so that it can be operated separately on the left and right sides so that the rotation on the floating side can be stopped, and it is driven on the grounded side. Power may be transmitted.

Further, in the above embodiment, the traveling device is provided with a single front wheel (1F) for steering and two driving rear wheels (1L), (1R), but it is configured as a four-wheel system. The specific configuration of the traveling device can be changed in various ways, such as by providing a crawler type traveling device.

Further, in the above embodiment, the work vehicle is configured for lawn mowing,
Although the case where the vehicle is automatically driven is illustrated, it may be in a form of boarding and artificially manipulating, or in a form of remotely controlling by radio or the like, and the present invention is applicable to various work vehicles, Various changes can be made to the specific configuration of each unit.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a turning device for a work vehicle according to the present invention,
FIG. 1 is an enlarged rear view of the lifting grounding body, FIG. 2 is a schematic rear view of the vehicle body, FIG. 3 is the same plan view, FIG. 4 is the same side view, and FIG.
FIG. 6 is a front view of the same, FIG. 6 is an explanatory view of a work mode, FIG. 7 is a block diagram of a control configuration, and FIG. 8 is a flow chart of control operation. (1F) …… Front wheel (travel device), (1L) …… Rear wheel (travel device), (1R) …… Rear wheel (travel device), (3) …… Elevating grounding body, (6) …… Grounding part, (V) ... Vehicle body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Suzuki 64, Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Katsumi Ito, 64, Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Manufacturing Co., Ltd. In-house (56) Reference JP-A-48-35528 (JP, A)

Claims (1)

(57) [Claims] 1. A descent state in which a traveling device of a plurality of traveling devices (1F), (1L), (1R) located on the turning center side descends so as to levitate, and the traveling device is grounded. An up-and-down grounding body (3) which can be raised and lowered to rise and which forms the turning center in the lowered state.
Is provided on the vehicle body (V), and at least the grounding portion (6) of the lifting-type grounding body (3) is configured to be rotatable about the longitudinal axis with respect to the vehicle body (V). A turning device for a working vehicle, wherein the plurality of traveling devices are provided with one front wheel (1F) for steering and two rear wheels (1L), (1R) for driving left and right, The lifting type grounding body (3) is provided with the two rear wheels (1L),
As one of the (1R) is moved up and down, at a position close to the lateral side of the rear wheel (1L or 1R) to be lifted between the two rear wheels (1L), (1R), and , A turning device for a work vehicle for lawn mowing, which is arranged at a position rearward of the rotational axis of the two rear wheels (1L) and (1R).