JP3378734B2 - Link mechanism for hydraulic control in paddy field vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control link mechanism for raising and lowering a working part such as a planting part in a paddy field working vehicle such as a passenger rice transplanter, and more specifically, a fluctuation of earth pressure acting on a float. Based on the above, the present invention relates to a link mechanism that adjusts the working unit to a constant height with respect to the rice field.

[0002]

2. Description of the Related Art Generally, a passenger rice transplanter is equipped with a lifting control lever which can be operated in a manual operation position and an automatic position,
While controlling the raising and lowering of the planting part by manual operation of the lever,
At the automatic position of the lever, the soil pressure acting on the float of the planting unit is detected, and the planting unit is automatically hydraulically moved up and down to reach the proper planting position.

As such a hydraulic control link mechanism,
Conventionally, for example, a mechanism as shown in FIG. 5 has been used.
That is, the sensing plate 62 is pivotally supported on the front portion of the float 14 by the connecting pin 62a, and the elongated hole 62b is formed in the upper middle portion of the sensing plate 62.
A pin 72 fixed to the Bowden wire 71 is fitted in b. A triangular fulcrum frame 74 is supported by a pin 74a on a bracket 73 fixed to the lower end of the link support frame 55, and a connecting rod 65 extending from the rear portion of the float is connected to one corner of the fulcrum frame 74. The swinging arms 75a and 75b fixed to the rotation fulcrum 75 are integrally connected to the other corners.

Further, the pin 72 is fixed to the tip of one swing arm 75a, and the sensing rod 39 is connected to the tip of the other swing arm 75b. The sensing rod 39 is a hydraulic control not shown. It is connected to the valve. The wire connecting pin 72 and the float connecting pin 62
A spring 76 is stretched between "a" and positions and sets the length between the wire connecting pin 72 and the float connecting pin 62a.

As described above, when the earth pressure acts on the float 14 and the front portion thereof is lifted, the hydraulic control valve is moved to the automatic raising position via the sensing plate 62 and the link mechanisms 75a, 75b, 39 to move up and down. When the link mechanism 8 raises the planting part 10 and, conversely, the earth pressure acting on the float 14 is small and the front part thereof lowers, the hydraulic control valve moves to the automatic lowering position to lower the planting part 10. Thus
The hydraulic control valve is automatically controlled based on the earth pressure acting on the float 14.

[0006]

By the way, according to the above-mentioned conventional link mechanism, the connection fulcrum (point A) between the elevating link mechanism 8 and the link support frame 55 and the rotation fulcrum 7 are provided.
5 (point B) and the length l (ell) are long, the connecting fulcrum (point A) and the pivot fulcrum 75 (point B) and the corresponding connecting fulcrums (A ′ at the front of the machine body). In the parallel link mechanism formed by the point) and the rotation fulcrum (point B '), the length l (L) between AB is likely to change due to the influence of part accuracy and backlash. There is a problem that the position of the rotation fulcrum 75 as a hydraulic pressure sensing point is displaced along with the vertical movement so that the parallel link action is broken and the hydraulic pressure sensing performance is constantly changed.

The present invention has been made to solve the above problems, and an object of the present invention is to accurately transmit the movement of the float to the hydraulic control valve and to make the airframe compact. An object of the present invention is to provide a hydraulic control link mechanism for a paddy field vehicle.

[0008]

According to the present invention, a working unit (10) having a float (14) is attached to a traveling machine body (5) via a lifting link mechanism (8) and a hydraulic cylinder device (1).
9) is lifted and supported by a hydraulic control valve (35) for controlling the hydraulic cylinder device (19),
Further, the hydraulic control valve (35) is connected to the float (14) through a linking means, and the hydraulic control valve is moved by the vertical movement of the float (14) based on the earth pressure fluctuation acting on the float (14). In the paddy field vehicle (1) that controls (35), the linkage means is connected to the float (1
4) a sensing plate (62) connected to the hydraulic control valve (35) and a link mechanism (42, 41, 41) connected to the hydraulic control valve (35).
22a, 22b, 39) and a swing arm (75
a, 75b), and the swing arm (75a, 75b)
b) is a connecting fulcrum (21) of the lifting link mechanism (8)
Is pivotally supported by a pivot fulcrum (75) disposed close to the robot, and the pivot fulcrum (75) and the connecting portion (72) of the sensing plate (62) and the swing arm (75a) are connected to the lifting link. It is characterized in that it is arranged so as to sandwich the connection fulcrum (21) of the mechanism (8).

Preferably, the rotation fulcrum (75) and the front
The sensing plate (62) and the swing arm (75a) are connected to each other.
The connection part (72) is arranged at a position substantially symmetrical with respect to the connection fulcrum (21) of the lifting link mechanism (8). (Operation) Based on the above configuration, when the lift control lever is in the automatic position, the hydraulic control valve (35) is automatically controlled based on the earth pressure acting on the float (14). For example, when earth pressure acts on the float (14) and the front portion thereof is lifted, the sensing plate (62) and the swing arms (75a, 75a).
b), sensing member (39), link members (22a, 22)
The hydraulic control valve (35) is moved to the automatic raising position via b), the arm (41), and the linking check link (42) to raise the working unit (10). On the contrary, when the earth pressure acting on the float (14) is small and the front portion of the float (14) is lowered, the control valve (35) is moved to the automatic lowering position to lower the working unit (10).

Therefore, the swing arm (75a, 75
b) is a connection fulcrum (21) of the lifting link mechanism (8)
Is pivotally supported by a rotation fulcrum (75) disposed in close proximity thereto, and the rotation fulcrum (75) and the connecting portion between the sensing plate (62) and the swing arm (75a) are The lifting fulcrum (8) is arranged so as to sandwich the connection fulcrum (21), and the rotation fulcrum (75) and the connection fulcrum (2).
1) is close to the work part (10), the positional deviation of the rotation fulcrum (75) due to the up-and-down movement of the working part (10) is avoided, and the movement of the float (14) accurately moves to the hydraulic control valve (35). Transmitted.

The above-mentioned reference numerals in parentheses are shown for reference to the drawings and do not limit the structure of the present invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. It should be noted that members that are the same as or correspond to those in the above-described conventional example are denoted by the same reference numerals and will be described.

As shown in FIG. 1, the riding rice transplanter 1 has a traveling machine body 5 supported by front wheels 2 and rear wheels 3, and the traveling machine body 5 has an engine 6 at the front portion of its front wheels.
Is mounted, and a driver's seat 9 is arranged so that the seat 7 is positioned in the middle portion between the front and rear wheels, that is, in the center of gravity of the machine. Further, a lifting link mechanism 8 is provided behind the traveling machine body 5.
The planting section 10 is supported movably up and down via the planting section 10, and the planting section 10 is provided with a large number of planters 11, ..., A flow plant 14, and a seedling platform 12 on which mat seedlings can be vertically mounted. ing.

A hydraulic cylinder device 19 is disposed between the front mission case 16 and the elevating link mechanism 8 of the traveling machine body 5, and the hydraulic cylinder device 19 expands and contracts to expand the hydraulic cylinder device 19. The attachment part 10 moves up and down.

That is, as shown in FIGS. 1 and 2,
A hydraulic control valve 35, which is a rotary pool valve, is installed on the seat column 25 below the driver's seat 9.
A play 36 having an elongated hole 36a is fixed to a shaft 35a integral with the spool. An arm 37 is rotatably supported on the shaft 35a, and the pin 32
Extends through the elongated hole 36a so as to abut the arm 37.

The arm 37 is connected to the flow box 14 through a linking means described later, and the hydraulic control valve 35 is controlled by the vertical movement of the float 14 based on the earth pressure fluctuation acting on the float 14. The hydraulic cylinder device 19 is adapted to expand and contract.

Incidentally, as shown in FIG.
Is supported by a rolling shaft (not shown) installed on the link support frame 55 at the rear end of the elevating link mechanism 8 so as to be able to roll in the left-right direction. Further, the float 14 in the planting section 10 is supported by a transmission case 61 at the center of the center thereof via a pantograph mechanism 60 so as to be vertically movable. Further, a sensing plate 62 is provided on the front portion of the float 14.
Are pivotally connected.

As shown in FIG. 2, the sensing plate 62 has a lower end pivotally supported on the float 14 by a connecting pin 62a, and an elongated hole 62b formed near the upper end thereof. A Bowden wire 71 is fixed to the upper end portion of the sensing plate 62, and a pin 72 fixed to the inner 71b of the wire 71 is fitted in the elongated hole 62b.

In the present embodiment, the linking means are link mechanisms 42, 41, 22a, 2 connected to the sensing plate 62 connected to the float 14 and the hydraulic control valve 35.
It is characterized in that it is composed of swinging arms 75a and 75b for connecting 2b and 39 .

That is, the link mechanism is composed of a continuous swing link 42 connected to the arm 37 on the hydraulic control valve 35 side.
And an arm 41 that is connected to the continuous check link 42 by a pin 46 and is pivotally attached (44) to the frame 40.
And the driver's seat 9 connected by the arm 41 and the pin 41a.
Pivot 17 of lower link support 18 and lower link 8b
Link members 22b, 2 which can swing integrally around the
2a and a sensing member 39 connected to each other via a pin 47 provided on the link members 22b, 22a. The sensing member 39 and the sensing plate 62 have a rotation fulcrum 75.
Are connected via swinging arms 75a and 75b that rotate around.

The sensing member 39, as shown in FIG.
A hole 2 fitted at one end into the pin 47 of the link member 22a
8, a plate 39a having a long hole 29 at the other end, and a pin 30 planted in the middle, a pin 31 planted at one end, and a pin 32 connected to the swing arm 75b at the other end.
And a plate 39b in which is planted, and a spring 33 is mounted between the pins 30 and 31.

The link member 22a has a large hole 24 formed in the center thereof, and the pivot support portion 17 and the pin 47 are provided at substantially symmetrical positions with the hole 24 sandwiched therebetween. It has a pivot part 17 and has a long hole 20 at the other end.
Is formed into an arm shape. Then, the fixed link 27 is inserted into the hole 24 of the link member 22a,
Further, restriction members 26a, 26b for restricting the rotation of the link members 22a, 22b are attached at appropriate positions on the periphery. The link member 22b and the arm 41 are
The pin 41a attached to the arm 41 and the long hole 2
They are connected via 0.

A pin 43 is planted in the intermediate portion of the linking link 42, and a spring 45 is stretched between the pin 43 and the frame 40 side.
The continuous check link 42 is always urged in the lowering direction (of the planting section 10).

Further, in this embodiment, the swing arms 75a and 75b are connected to the connecting fulcrum 2 of the lifting link mechanism 8.
While pivot at pivot point 75 which is arranged close to 1, and the pivoting fulcrum 75, the sensing plate 62 and the swing arm 75
The connecting portion 72 with a is a fulcrum for connecting the lifting link mechanism 8.
It is characterized in that it is arranged with 21 in between.

As shown in FIG . 4, the swing arm 75 is
Each of a and 75b is formed of a fork-shaped arm that is swingable as a unit around the rotation fulcrum 75. 2 and 3
As shown in FIG. 5, the swing arms 75a, 75b are connected by the connecting plates 23, 23 attached to the horizontal shaft 21 as a connecting fulcrum connecting the left and right lower links 8b, 8b at the rear part of the elevating link mechanism 8. It is arranged close to the horizontal axis 21. The connecting plate 23 is rotatable around the horizontal shaft 21.
Are supported by the swing arm 75a, 75b.
The dynamic fulcrum 75 is located at a position close to the horizontal axis 21, and
It is rotatably supported on the tip of the connection plate 23.

Then, as shown in FIG. 2, the sensing plate 62 and the swing arm 75a are connected to each other by the sensing plate 62.
The pin 72 as a connecting portion fitted in the long hole 62b of the
The pin 72 and the rotation fulcrum 75 are arranged at substantially symmetrical positions with the horizontal shaft 21 connecting the lower links 8b, 8b interposed therebetween.
For this reason, the swing arm 75a is curved in an arc shape so as not to contact the horizontal shaft 21.

Further, the sensing member 39 is connected to the tip of the swing arm 75b through the pin 32, while a spring 76 is stretched between the wire connecting pin 72 and the float connecting pin 62a. The spring 76 stretches the inner wire 7lb to position and set the working length of the sensing plate 62, which is the length between the wire connecting pin 72 and the float connecting pin 62a.

The bracket 75c connected (fixed) to the rear part of the swing arms 75a and 75b is planted via the plate 64 , the connecting rod 65 and the rod arm 66 .
It is connected to the depth adjusting lever 68. The plate
64 is a link support as shown in FIGS. 2, 3 and 4.
The pivot pin 64c is attached to the metal fitting 63 fixed to the frame 55.
It has a plate piece 64b that is rotatably supported,
One end of the plate piece 64b is inserted through the plate piece 64a.
While being connected to the bracket 75c,
The other end of the rate piece 64b is connected to a planting depth adjusting lever 68 via a connecting rod 65 and a rod arm 66.

Further, in the present embodiment, the rotation fulcrum 7
5, a connecting portion between the sensing plate 62 and the swing arm 75a
72 is substantially symmetrical with respect to the horizontal axis 21 of the lifting link mechanism 8.
It is characterized by being placed in a position .

As described above, the swing arm 75a,
The tip side of one arm 75a in 75b is pin 7
2 is connected to the sensing plate 62, and the tip end side of the other arm 75b is connected to the sensing member 39 via a pin 32 . Also, as mentioned above,
The fulcrum 75 and the pin 72 serve as the horizontal axis 2 of the lifting link mechanism 8.
They are arranged at substantially symmetrical positions with the 1 in between .

[0031]

Further, in the present embodiment, as shown in FIG. 3, the link structure from the hydraulic control valve 35 to the float 14 is arranged on the inner side of the lower links 8b, 8b on the left and right sides of the body.

That is, the hydraulic control valve 35 is outside the lower link 8b in a plan view, and
It is possible to install an important hydraulic link inside the fuselage by installing it at almost the same height. By doing so, the influence of the external force of the elevating and lowering link mechanism is reduced, the deformation of the hydraulic link is prevented, and the lower link 8b, which is the main frame of the machine body, is provided. I am less. Similarly, by configuring the hydraulic link near the center of the machine body, it is possible to reduce the influence of left-right balance.

Next, the operation of the above-described embodiment will be described.

When the lift control lever is operated to the automatic position,
Based on the earth pressure acting on the float 14, the swing arm 75
The hydraulic control valve 35 is controlled by the continuous check link 42 via a and 75b. That is, when the planting part 10 is in the proper planting position, the control plate 36 is in the fixed position via the arm 37 and the pin 32, and the hydraulic control valve 35 is held to hold the planting part 10 in that position. To do.

From this state, when the planting part 10 rises with respect to the rice field and the earth pressure acting on the float 14 decreases, the front part of the float 14 descends, and the movement is detected by the sensing plate 62.
And the pin 7 positioned at a predetermined position of the long hole 62b.
2 is transmitted as rotation in the counterclockwise direction (FIG. 2) to the swing arm 75a, and the swing arm 75b is also rotated in the same direction via the swing fulcrum 75 to press the sensing member 39.

The pressing force at this time causes the link members 22a and 22b to rotate counterclockwise about the pivotal support portion 17, and accordingly the arm 41 to rotate clockwise about the fulcrum 44, and further the continuous drafting link. 42 is moved clockwise around the fulcrum 44. The movement of the link 42 causes the arm 37 to rotate clockwise about the shaft 35a, and the pin 32 is in contact with the arm 37, so that the control plate 36 is integrated with the arm 37 via the pin 32. Rotates to the lowered position, and the hydraulic control valve 35 is
Switching to drain the oil in the hydraulic cylinder device 19,
The cylinder device is contracted to lower the planting part 10.

On the contrary, when the planting part 10 descends and the earth pressure acting on the float 14 increases, the front part of the float 14 is lifted, and the movement is detected by the sensing plate 62 and the swing arm 7.
5a, 75b, sensing member 39, link members 22a, 22
b and the arm 41, the continuous check link 42 is set as a fulcrum 44
In contrast, the arm 37 is rotated counterclockwise by rotating counterclockwise, and the control plate 36 is integrated with the arm 37.
Rotate to the raised position.

As a result, the hydraulic control valve 35 is switched to send pressure oil to the hydraulic cylinder device 19, and the rod of the cylinder device 19 is extended to raise the planting portion 10 to the proper position.

In the above, the swing arms 75a, 75b
Since the rotation fulcrum 75 of is arranged close to the horizontal shaft 21 connecting the left and right lower links 8b, 8b, the planting portion 1
An advantage that the vertical movement of the float 14 due to the fluctuation of the earth pressure acting on the float 14 is sensed as it is and the sensing performance is maintained without the rotation fulcrum 75 serving as a hydraulic pressure sensing point being displaced even when 0 is moved up and down. Have.

The regulating member 26a is a fixed link 27.
The upper limit position is determined by abutting against the fixed link 27, and the lower limit position is determined by abutment with the fixed link 27. Furthermore, the swing arm 7
The position of the rotation fulcrum 75 of 5a and 75b is positioned by operating the planting depth adjusting lever 68.

[0042]

As described above, according to the present invention,
A working unit having a float is lifted and supported by a hydraulic cylinder device via a lift link mechanism on the traveling machine body,
A hydraulic control valve for controlling the hydraulic cylinder device is provided, the hydraulic control valve is further connected to the float through a linking means, and the float is moved up and down based on a fluctuation in earth pressure acting on the float. In a paddy field vehicle that controls a hydraulic control valve, the linking means includes a swinging arm that connects a sensing plate connected to a float and a link mechanism connected to the hydraulic control valve, The arm is pivotally supported by a rotation fulcrum arranged in proximity to the connection fulcrum of the elevating and lowering link mechanism, and the rotation fulcrum and the connecting portion between the sensing plate and the swing arm are connected to the connecting and fulcrum of the elevating and lowering link mechanism. By arranging them sandwiched, the dimensional variation of the rotation fulcrum due to the lifting operation of the working unit is reduced, and therefore the movement of the float is accurately transmitted to the hydraulic control valve. It can be. Further, the sensing rod from the float and the pivot can be connected in the shortest distance, and the size of the machine can be reduced. Furthermore, since the rotation fulcrum of the swing arm is provided around the connection fulcrum of the elevating link mechanism, variations due to the machine body are reduced.

[0043]

[Brief description of drawings]

FIG. 1 is a side view of a riding rice transplanter to which the present invention is applied.

FIG. 2 is a diagram showing an overall configuration of a hydraulic control link mechanism according to the present invention.

FIG. 3 is a plan view of FIG.

FIG. 4 is an exploded perspective view of FIG.

FIG. 5 is a side view of a float portion of a conventional hydraulic control link mechanism.

[Explanation of symbols]

1 Passenger rice transplanter 5 traveling aircraft 8 lifting link mechanism 8a Lower Link 10 planting department 14 float 17 pivotal branch 19 Hydraulic cylinder device 21 Horizontal axis 22 Link members 23 Connection plate 35 Hydraulic control valve 39 Sensing member 40 frames 41 Arm 42 Link Link 55 Link support frame 62 Sensing play 75 rotation fulcrum 75a, 75b swinging arm

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Publication 8-11010 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) A01C 11/02

Claims (2)

(57) [Claims] 1. A traveling machine body is provided with a hydraulic control valve for controlling the hydraulic cylinder device, the working part having a float being lifted and lowered by a hydraulic cylinder device via a lifting link mechanism, and the hydraulic control valve is further provided. In a paddy work vehicle in which the hydraulic control valve is controlled by vertically moving the float based on earth pressure fluctuations acting on the float by connecting the float to the float. It comprises a swing arm that connects the connected sensing plate and a link mechanism connected to the hydraulic control valve, and the swing arm is pivotally supported by a rotation fulcrum arranged in proximity to the connection fulcrum of the lifting link mechanism. In addition, the rotation fulcrum and the connecting portion between the sensing plate and the swing arm are arranged with the connecting fulcrum of the elevating link mechanism interposed therebetween. Link mechanism for hydraulic control in paddy work vehicle. 2. The swing fulcrum, the sensing plate and the rocker
The link mechanism for hydraulic control in a paddy work vehicle according to claim 1 , wherein a connecting portion with the moving arm is arranged at substantially symmetrical positions with respect to a connecting fulcrum of the lifting link mechanism.