Technical Field
[0001]
The present invention relates to a paddy field work machine, such as a riding-type
rice transplanter and a riding-type direct seeder, and, in particular, to a configuration for
lifting and lowering a work device on a rear portion of a machine body.
10
Background Art
[0002]
As disclosed in Patent Literature 1, a riding-type rice transplanter, which is an
example of a paddy field work machine, includes a float that is liftably supported by a lower
15 portion of a work device and configured to contact and follow a paddy field surface, a height
sensor mounted on the work device, and a rod connected to the float and the height sensor.
This configuration allows a work height from the float (paddy field surface) to the
work device to be detected by the height sensor and the work device to be lifted and lowered
so that the work height becomes equal to a preset height that is set in advance.
20
Citation List
Patent Literature
[0003]
Patent Literature 1
25 Japanese Unexamined Patent Application Publication, Kokai, No. 2013-59267
Summary of Invention
Technical Problem
[0004]
30 When the paddy field work machine travels, mud and water are scattered rearward
from the machine body. Thus, there is room for improvement in making mud and water
scattered rearward less likely to adhere to the height sensor.
The present invention provides a paddy field work machine that supports a work
device by a rear portion of a machine body and aims at making mud and water scattered
35 rearward from the machine body less likely to adhere to a height sensor.
Solution to Problem
[0005]
A paddy field work machine of the present invention includes a work device, a
3
lifting and lowering mechanism, a float, a height sensor, a link mechanism, and a control
section. The work device is held by a rear portion of a machine body in such a manner as to
be capable of being lifted and lowered and configured to supply material to a paddy field
surface. The lifting and lowering mechanism is capable of lifting and lowering the work
5 device with respect to the machine body. The float is held by a lower portion of the work
device in such a manner as to be capable of being lifted and lowered and configured to
contact and follow the paddy field surface. The height sensor is located at a portion of the
work device rearward of a front end portion of the float in a side view. The link mechanism
is connected to the float and the height sensor. The link mechanism is configured to transmit
10 lifting and lowering operation of the float with respect to the work device to the height
sensor so that the height sensor detects a work height from the float to the work device. The
control section is configured to operate the lifting and lowering mechanism in accordance
with a detection value of the height sensor so that the work height becomes equal to a preset
height that is set in advance.
15 [0006]
According to the present invention, the float and the height sensor are located on
the work device on the rear portion of the machine body, and with the link mechanism
connected to the float and the height sensor, the height sensor is located rearward of the
front end portion of the float and is spaced rearwardly apart from the machine body.
20 Thus, even if mud and water are scattered rearward from the machine body, the
mud and water are unlikely to adhere to the height sensor. This prevents a decrease in the
durability of the height sensor that is otherwise caused by the adhesion of mud and water.
[0007]
In the present invention, the link mechanism may preferably include a swingable
25 member and a connection member. The swingable member is held by the work device in
such a manner as to be swingable about a support axis extending in a left-right direction.
The swingable member includes a first portion that extends forward from the support axis
and is connected to the float and a second portion extending upward from the support axis.
The connection member extends in a front-back direction and connects to an input portion
30 of the height sensor and the second portion.
[0008]
According to the present invention, the link mechanism, which is connected to the
float and the height sensor, includes the swingable member and the connection member.
When the work height of the work device changes with respect to the float, which contacts
35 and follows the paddy field surface, the swingable member of the link mechanism swings
about the support axis in accordance with the change, causing the connection member to
move forward and backward. This transmits the lifting and lowering operation of the float
with respect to the work device to the height sensor, so that the height sensor detects the
4
work height from the float to the work device.
[0009]
According to the present invention, the swingable member includes the second
portion, which extends upward from the support axis. The connection member extending in
5 the front-back direction is connected to the input portion of the height sensor and the second
portion of the swingable member. The second portion of the swingable member allows the
height sensor to be located at a relatively high position from the float (paddy field surface),
which is advantageous in inhibiting mud and water from adhering to the height sensor.
[0010]
10 In the present invention, the input portion may preferably extend downward from
the height sensor, and a lower portion of the input portion may preferably be connected to a
rear portion of the connection member.
[0011]
According to the present invention, in the case in which the connection member is
15 connected to the input portion of the height sensor and the second portion of the swingable
member, the input portion of the height sensor extends downward from the height sensor.
Thus, the position of the height sensor is higher than the swingable member by the
amount that the input portion of the height sensor extends downward. This allows the height
sensor to be located at a relatively high position from the float (paddy field surface), which
20 is advantageous in inhibiting mud and water from adhering to the height sensor.
[0012]
The present invention may further preferably include a spring support and a tension
spring. The spring support is located rearward of the swingable member. The tension spring
is connected to the first portion and the spring support. Urging force of the tension spring
25 urges the float downward with respect to the work device via the swingable member.
[0013]
The paddy field work machine may be provided with a spring that urges the float
downward with respect to the work device.
According to the present invention, the tension spring is connected to the first
30 portion of the swingable member and extends rearward from the first portion of the
swingable member. Thus, the tension spring is located at a relatively low position in a
compact manner. Since the tension spring is located at a low position, the tension spring
hardly affects the arrangement of the height sensor.
[0014]
35 The present invention may further preferably include a preset height changing
section and an interlock portion. The preset height changing section is capable of changing
the preset height by vertically changing a support position of the float with respect to the
work device. The interlock portion is configured to lower the position of the support axis
5
with respect to the work device as the preset height is raised by operation of the preset height
changing section and to raise the position of the support axis with respect to the work device
as the preset height is lowered by operation of the preset height changing section.
[0015]
5 The paddy field work machine, such as a riding-type rice transplanter, may include
a preset height changing section that is capable of changing the preset height by vertically
changing a support position of the float with respect to the work device. In the riding-type
rice transplanter, the planting depth of seedlings by the seedling planting device is changed
by changing the preset height from the float (paddy field surface) to the seedling planting
10 device (work device).
[0016]
According to the present invention, as the preset height is changed by the operation
of the preset height changing section, the position of the support axis of the swingable
member is changed in the same manner as the support position of the float. Thus, even if
15 the preset height is changed, the vertical positional relationship between the float and the
support axis of the swingable member is changed little.
In contrast, since the height sensor is located on the work device, when the support
position of the float is changed by the preset height changing section, the vertical positional
relationship of the float and the support axis of the swingable member with respect to the
20 height sensor changes.
[0017]
According to the present invention, since the connection member is connected to
the input portion of the height sensor and the second portion of the swingable member, even
when the vertical positional relationship of the float and the support axis of the swingable
25 member with respect to the height sensor is changed as described above, the abovedescribed change in the vertical positional relationship is absorbed by the swinging of the
connection member about the connection point with the second portion of the swingable
member and the swinging of the connection member about the connection point with the
input portion of the height sensor.
30 Thus, even when the support position of the float is changed by the preset height
changing section, the lifting and lowering operation of the float with respect to the work
device is appropriately transmitted to the height sensor, allowing the height sensor to
appropriately detect the work height from the float to the work device.
[0018]
35 The present invention may further preferably include a spring support, a tension
spring, and a spring interlock portion. The spring support is located rearward of the
swingable member. The tension spring is connected to the first portion and the spring
support. Urging force of the tension spring urges the float downward with respect to the
6
work device via the swingable member. The spring interlock portion is configured to change
the position of the spring support in the front-back direction in response to the operation of
the preset height changing section, so that the urging force of the tension spring is
maintained constant.
5 [0019]
The paddy field work machine may include a spring that urges the float downward
with respect to the work device.
According to the present invention, the tension spring is connected to the first
portion of the swingable member and extends rearward from the first portion of the
10 swingable member. Thus, the tension spring is located at a relatively low position in a
compact manner. Since the tension spring is located at a low position, the tension spring
hardly affects the arrangement of the height sensor.
[0020]
According to the present invention, when the preset height is changed by the
15 operation of the preset height changing section as described above, so that the position of
the support axis of the swingable member, to which the tension spring is connected, is
changed, the position of the spring support is changed in the front-back direction by the
spring interlock portion, so that the change in the fore-and-aft spacing between the first
portion of the swingable member and the spring support is kept little and the urging force
20 of the tension spring is maintained constant.
Thus, even when the preset height is changed, so that the support position of the
float is vertically changed, the float contacts and follows the paddy field surface in a stable
manner.
[0021]
25 The present invention may further preferably include at least one support frame
and a work portion. The support frame extends in a left-right direction at a portion of the
work device rearward of the front end portion of the float. The work portion is configured
to supply the material to the paddy field surface. The work portion is coupled to the support
frame and extends rearward from the support frame. The height sensor is located rearward
30 of the at least one support frame in a side view.
[0022]
The paddy field work machine may be configured to improve the rigidity of the
entire work device with the support frame located in the work device to extend in the leftright direction and with the work portion that supplies material to the paddy field surface
35 coupled to the support frame and extending rearward. With this configuration, the support
frame may be located at a portion of the work device rearward of the front end portion of
the float.
[0023]
7
According to the present invention, with the above-described configuration, the
height sensor is located rearward of the support frame in a side view, so that the height
sensor is spaced rearwardly apart from the machine body, which is advantageous in making
mud and water unlikely to adhere to the height sensor.
5 [0024]
In the present invention, the at least one support frame may preferably include right
and left support frames. The paddy field work machine may preferably be configured to be
in an in-operation state in which the right and left support frames extend in the left-right
direction with a central end portion of the right support frame, which central end portion is
10 located at a laterally central position of the work device, facing a central end portion of the
left support frame, which central end portion is located at a laterally central position of the
work device, with an interval, and an at-rest state in which the right and left support frames
extend in the front-back direction and are located next to each other in the left-right direction.
The paddy field work machine may preferably include a switching mechanism that is
15 capable of switching the work device between the in-operation state and the at-rest state.
The link mechanism may preferably be located between the central end portions of the right
and left support frames in the in-operation state in a plan view.
[0025]
The paddy field work machine may be configured in such a manner that the work
20 device includes right and left support frames and to be capable of switching between the inoperation state, in which the right and left support frames extend in the left-right direction
with the right and left support frames facing each other, and the at-rest state, in which the
right and left support frames are arranged next to each other in the left-right direction with
the right and left support frames extending in the front-back direction. Since the lateral width
25 of the work device is reduced in the at-rest state of the work device, it is advantageous in
carrying or storing the paddy field work machine.
[0026]
According to the present invention, in the in-operation state of the work device, the
central end portion of the right support frame and the central end portion of the left support
30 frame face each other with an interval to provide a space in the vicinity of the laterally
central portion of the work device.
[0027]
According to the present invention, since the link mechanism is located between
the central end portions of the right and left support frames in the in-operation state of the
35 work device in a plan view, the link mechanism is located in the vicinity of the laterally
central portion of the work device without difficulty. Thus, the link mechanism is connected
to the float in the vicinity of the laterally central portion of the work device without difficulty,
and the structure is easily achieved that detects the work height in accordance with the float
8
in the vicinity of the laterally central portion of the work device.
[0028]
In the present invention, the support frame may preferably be attached to one of
the central end portions of the right and left support frames. The height sensor and the link
5 mechanism may preferably be held by the support member.
[0029]
According to the present invention, in arranging the link mechanism between the
central end portions of the right and left support frames in the in-operation state of the work
device in a plan view as described above, the height sensor and the link mechanism are held
10 by the support member attached to the central end portion of one of the right and left support
frames. This stabilizes the position of the height sensor and the link mechanism.
[0030]
According to the present invention, in the at-rest state, the support frames may
preferably extend in the front-back direction so that the central end portions of the support
15 frames are located rearward of end portions of the support frames opposite to the central
end portions.
[0031]
According to the present invention, when the work device is set to the at-rest state,
the central end portions of the support frames are located at the rear (further from the rear
20 portion of the machine body). Thus, an operator can perform maintenance work on the
height sensor and the link mechanism without being affected by the machine body.
Brief Description of Drawings
[0032]
25 FIG. 1 is a left-side view of a riding-type rice transplanter.
FIG. 2 is a plan view of the riding-type rice transplanter.
FIG. 3 is a plan view of a seedling planting device in an in-operation state.
FIG. 4 is a plan view of the seedling planting device in an at-rest state.
FIG. 5 is a plan view of a center float, a height sensor, a link mechanism, and their
30 surrounding structure when the seedling planting device is in the in-operation state.
FIG. 6 is a front view of the center float, the height sensor, the link mechanism, and
their surrounding structure when the seedling planting device is in the in-operation state.
FIG. 7 is an exploded perspective view of the center float, the height sensor, and
the link mechanism.
35 FIG. 8 is a schematic diagram illustrating how lifting and lowering of the seedling
planting device are controlled.
FIG. 9 is a left-side view of the center float, the height sensor, the link mechanism,
and their surrounding structure illustrating the state in which a preset height (preset planting
9
depth) is set to the minimum height (deepest).
FIG. 10 is a left-side view of the center float, the height sensor, the link mechanism,
and their surrounding structure illustrating the state in which the preset height (preset
planting depth) is set to the maximum height (shallowest).
5
Description of Embodiments
[0033]
FIGs. 1 to 10 show a 10-row planting riding-type rice transplanter, which is an
example of a paddy field work machine. In FIGs. 1 to 10, F indicates the front direction, B
10 indicates the back direction, U indicates the up direction, D indicates the down direction, R
indicates the right direction, and L indicates the left direction.
[0034]
(General Arrangement of Riding-Type Rice Transplanter)
As shown in FIGs. 1 and 2, the riding-type rice transplanter includes a machine
15 body 30 including right and left front wheels 1 and right and left rear wheels 2. A link
mechanism 3 and a hydraulic cylinder 4 (corresponding to a lifting and lowering
mechanism), which lifts and lowers the link mechanism 3, are provided on the rear portion
of the machine body 30. A seedling planting device 5 (corresponding to a work device) is
supported by the rear portion of the link mechanism 3.
20 [0035]
With the above configuration, the seedling planting device 5, which plants
seedlings (corresponding to material) on a paddy field surface G, is supported by the rear
portion of the machine body 30 in such a manner as to be capable of being lifted and lowered.
The seedling planting device 5 can be lifted and lowered with respect to the machine body
25 30 by the hydraulic cylinder 4.
[0036]
(General Arrangement of Seedling Planting Device, Fertilizer Applicator, and Chemical
Sprayer)
As shown in FIGs. 1 and 2, the seedling planting device 5 includes, for example,
30 five planting transmission cases 6 (corresponding to a work portion), rotary cases 7, planting
arms 8, a center float 9 (corresponding to a float), four floats 10, and a seedling tray 11. The
planting transmission cases 6 are located at predetermined intervals in the left-right direction.
Each rotary case 7 is rotatably supported by the right portion or the left portion of one of the
planting transmission cases 6. The planting arms 8 are supported by both ends of each rotary
35 case 7.
[0037]
A fertilizer applicator 12 is supported by the rear portion of the machine body 30
and the seedling planting device 5. The fertilizer applicator 12 includes, for example, a
10
hopper 13, a feeder 14, a blower 15, a ditching machine 16, and a hose 17.
[0038]
A driver’s seat 18 is supported by the rear portion of the machine body 30. The
hopper 13, which stores fertilizer, and the feeder 14 of the fertilizer applicator 12 are located
5 on a portion of the machine body 30 behind the driver’s seat 18. The blower 15 is located
on the left outer side of the feeder 14. The ditching machine 16 is attached to the center float
9 and the floats 10. The hose 17 is connected to the feeder 14 and the ditching machine 16.
[0039]
In the seedling planting device 5, the planting arms 8 (rotary cases 7) are drivingly
10 rotated while the seedling tray 11 is cross-fed, so that the planting arms 8 pick seedlings
from the bottom portion of the seedling tray 11 to plant (supply) the seedlings to the paddy
field surface G.
[0040]
In the fertilizer applicator 12, the fertilizer in the hopper 13 is fed by the feeder 14
15 and supplied to the ditching machine 16 through the hose 17 by the carrier air of the blower
15. Thus, while ditches are formed in the paddy field surface G by the ditching machine 16,
the fertilizer is supplied to the ditches in the paddy field surface G from the ditching machine
16.
[0041]
20 A chemical sprayer 28 is supported by a support frame 29 coupled to the planting
transmission case 6 at the center. A chemical agent such as herbicide is sprayed from the
chemical sprayer 28 to the paddy field surface G rearward of the seedling planting device 5.
[0042]
(Configuration for Switching Seedling Planting Device between In-Operation State and At25 Rest State)
As shown in FIG. 6, a support frame 19 is provided that is frame-shaped as viewed
from the front. The support frame 19 includes, for example, an upper portion 19a and a
lower portion 19b, which are located to extend in the left-right direction, right and left
vertical portions 19c, which couple the upper portion 19a to the lower portion 19b, and a
30 bracket 19d, which is coupled to the lower portion 19b. The bracket 19d of the support frame
19 is supported by a vertical link 3a (refer to FIG. 1) on the rear portion of the link
mechanism 3 to be able to roll about an axis P3 extending in the front-back direction.
[0043]
As shown in FIGs. 3 and 6, a right support arm 20 (corresponding to a switching
35 mechanism) is supported by the right portions of the upper portion 19a and the lower portion
19b of the support frame 19 in such a manner as to be swingable about an axis P1 extending
in the up-down direction. A left support arm 20 (corresponding to the switching mechanism)
is supported by the left portions of the upper portion 19a and the lower portion 19b of the
11
support frame 19 in such a manner as to be swingable about an axis P1 extending in the updown direction.
[0044]
As shown in FIG. 3, right and left support frames 21 and 22 are provided, and a
5 coupling portion 23 is coupled to each of the right and left support frames 21 and 22. The
coupling portion 23 of the right support frame 21 is supported by the end portion of the right
support arm 20 in such a manner as to be swingable about an axis P2 extending in the updown direction. The coupling portion 23 of the left support frame 22 is supported by the end
portion of the left support arm 20 in such a manner as to be swingable about an axis P2
10 extending in the up-down direction.
[0045]
Three of the planting transmission cases 6 are coupled to the right support frame
21 and extend rearward from the right support frame 21. The center float 9 and two of the
floats 10 are supported by the right support frame 21. Two of the planting transmission cases
15 6 are coupled to the left support frame 22 and extend rearward from the left support frame
22. Two of the floats 10 are supported by the left support frame 22.
[0046]
As shown in FIGs. 5, 8, 9, and 10, in the seedling planting device 5, the right and
left support frames 21 and 22 are located to extend in the left-right direction at a portion
20 rearward of front end portions 9a and 10a of the center float 9 and the floats 10 in a side
view and a plan view.
[0047]
The state shown in FIGs. 1, 2, and 3 is an in-operation state A1. In this state, the
left end portion of the right support frame 21, which left end portion is a central end portion
25 21a located at a laterally central position of the seedling planting device 5, faces the right
end portion of the left support frame 22, which right end portion is a central end portion 22a
located at a laterally central position of the seedling planting device 5, with an interval, and
the right and left support frames 21 and 22 are located to extend in the left-right direction.
[0048]
30 The in-operation state A1 of the seedling planting device 5 is switched to an at-rest
state A2 as described below.
The seedling tray 11 is separated at a boundary between a right portion 11a
including six rows and a left portion 11b including four rows. The right portion 11a of the
seedling tray 11 belongs to the right support frame 21. The left portion 11b of the seedling
35 tray 11 belongs to the left support frame 22.
[0049]
Subsequently, the right and left support arms 20 are allowed to swing rearward
about the axis P1 while swinging the right support frame 21 counterclockwise in FIG. 3
12
about the axis P2 and the left support frame 22 clockwise in FIG. 3 about the axis P2.
[0050]
This allows the seedling planting device 5 to be set to the at-rest state A2 in which
the right and left support frames 21 and 22 extend in the front-back direction and are located
5 next to each other in the left-right direction as shown in FIG. 4.
[0051]
In the at-rest state A2 of the seedling planting device 5, the support frames 21 and
22 are located to extend in the front-back direction so that the central end portions 21a and
22a of the support frames 21 and 22 are located rearward of end portions 21b and 22b of the
10 support frames 21 and 22 opposite to the central end portions 21a and 22a.
[0052]
(Configuration for Supporting Center Float and Floats)
As shown in FIGs. 5 to 8, right and left fulcrum frames 25 and 26 are provided.
The right fulcrum frame 25 is supported by the lower portions of the three planting
15 transmission cases 6 coupled to the right support frame 21 to be rotatable about an axis P4
extending in the left-right direction. The left fulcrum frame 26 is supported by the lower
portions of the two planting transmission cases 6 coupled to the left support frame 22 to be
rotatable about the axis P4 extending in the left-right direction.

Claim 1
A paddy field work machine, comprising:
a work device held by a rear portion of a machine body in such a manner as to be
5 capable of being lifted and lowered and configured to supply material to a paddy field
surface;
a lifting and lowering mechanism capable of lifting and lowering the work device
with respect to the machine body;
a float held by a lower portion of the work device in such a manner as to be capable
10 of being lifted and lowered and configured to contact and follow the paddy field surface;
a height sensor located at a portion of the work device rearward of a front end
portion of the float in a side view;
a link mechanism connected to the float and the height sensor, the link mechanism
being configured to transmit lifting and lowering operation of the float with respect to the
15 work device to the height sensor so that the height sensor detects a work height from the
float to the work device; and
a control section configured to operate the lifting and lowering mechanism in
accordance with a detection value of the height sensor so that the work height becomes
equal to a preset height that is set in advance.
20
Claim 2
The paddy field work machine according to claim 1, wherein
the link mechanism includes:
a swingable member held by the work device in such a manner as to be swingable
25 about a support axis extending in a left-right direction, the swingable member including:
a first portion that extends forward from the support axis and is connected
to the float; and
a second portion extending upward from the support axis; and
a connection member extending in a front-back direction and connected to an input
30 portion of the height sensor and the second portion.
Claim 3
The paddy field work machine according to claim 2, wherein
the input portion extends downward from the height sensor, and a lower portion of
35 the input portion is connected to a rear portion of the connection member.
Claim 4
The paddy field work machine according to claim 2 or 3, further comprising:
23
a spring support located rearward of the swingable member; and
a tension spring connected to the first portion and the spring support,
wherein urging force of the tension spring urges the float downward with respect
to the work device via the swingable member.
5
Claim 5
The paddy field work machine according to any one of claims 2 to 4, further
comprising:
a preset height changing section that is capable of changing the preset height by
10 vertically changing a support position of the float with respect to the work device; and
an interlock portion configured to lower the position of the support axis with
respect to the work device as the preset height is raised by operation of the preset height
changing section and to raise the position of the support axis with respect to the work device
as the preset height is lowered by operation of the preset height changing section.
15
Claim 6
The paddy field work machine according to claim 5, further comprising:
a spring support located rearward of the swingable member;
a tension spring connected to the first portion and the spring support, wherein
20 urging force of the tension spring urges the float downward with respect to the work device
via the swingable member; and
a spring interlock portion configured to change the position of the spring support
in the front-back direction in response to the operation of the preset height changing section,
so that the urging force of the tension spring is maintained constant.
25
Claim 7
The paddy field work machine according to any one of claims 1 to 6, further
comprising:
at least one support frame extending in a left-right direction at a portion of the work
30 device rearward of the front end portion of the float; and
a work portion configured to supply the material to the paddy field surface, the
work portion being coupled to the support frame and extending rearward from the support
frame,
wherein the height sensor is located rearward of the at least one support frame in a
35 side view.
Claim 8
The paddy field work machine according to claim 7, wherein
24
the at least one support frame includes right and left support frames,
the paddy field work machine is configured to be in:
an in-operation state in which the right and left support frames extend in
the left-right direction with a central end portion of the right support frame, which central
5 end portion is located at a laterally central position of the work device, facing a central end
portion of the left support frame, which central end portion is located at a laterally central
position of the work device, with an interval, and
an at-rest state in which the right and left support frames extend in the
front-back direction and are located next to each other in the left-right direction,
10 the paddy field work machine includes a switching mechanism that is capable of
switching the work device between the in-operation state and the at-rest state, and
the link mechanism is located between the central end portions of the right and left
support frames in the in-operation state in a plan view.
15 Claim 9
The paddy field work machine according to claim 8, wherein
the support member is attached to one of the central end portions of the right and
left support frames, and
the height sensor and the link mechanism are held by the support member.
20
Claim 10
The paddy field work machine according to claim 9, wherein
in the at-rest state, the support frames extend in the front-back direction so that the
central end portions of the support frames are located rearward of end portions of the support
25 frames opposite to the central end portions.