JPH0123084B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rice transplanter.

In general, rice transplanters must be controlled so that the seedlings can always be planted at a constant depth in the field using the planting claws of the seedling planting device, and the distance between the seedling planting device and the mud surface of the field is constant. .

Conventionally, the seedling planting device is equipped with a float that slides by pressing against the mud surface of the field, and most of the weight of the seedling planting device is supported by the float. By providing a detection element to detect a change in the weight of the seedling planting device and adjusting the supporting force of the seedling planting device according to the detected amount, the distance between the seedling planting device and the mud surface is controlled to a constant value. Ta.

However, the load applied to the float fluctuates due to changes in the hardness of the mud surface, as well as due to a decrease in the amount of seedlings on the seedling platform during rice planting operations, and a change in the center of gravity due to horizontal movement of the seedling platform. Since the distance between the seedling planting device and the planting surface always changes in a complicated manner, it is not possible to accurately control the distance between the seedling planting device and the planting surface, and therefore, there is a problem in that the seedlings cannot be planted at a constant planting depth.

In addition, since floats are used, the faster the planting speed in rice transplanting operation is, the greater the mud pushing by the floats, causing problems such as the already planted seedlings being buried under the mud surface. It was difficult.

The present invention was invented in order to solve the above problems, and its purpose is to reduce the amount of seedlings on the seedling tray and reduce the amount of seedlings placed on the seedling stand, regardless of changes in the hardness of the mud surface in the field. To provide a rice transplanter capable of planting seedlings at a constant planting depth in a field regardless of changes in the center of gravity due to horizontal movement of the table, and also capable of easily performing high-speed planting.

That is, the present invention is configured such that the seedling planting device is connected and supported by the machine body via a support device so as to be movable up and down, and this support device is suspended by a lifting device to carry the entire load of the seedling planting device. On the other hand, a detection device for detecting a planting surface of seedlings is provided in either the machine body or the seedling planting device, and the drive of the lifting device is controlled by a detection signal from the detection device. That is.

Hereinafter, embodiments of the rice transplanter of the present invention will be described based on the drawings.

In the figure, 1 is a fuselage, which is divided into two parts: a front fuselage 2 and a rear fuselage 3. A pair of front wheels 4 and a pair of rear wheels 5 are attached to the front and rear fuselages 2 and 3, respectively. 2 is provided with an operation box 7 with a handle 6 and a seat 8, and the rear body 3 is provided with an engine 9, and the front and rear bodies 2 and 3 are connected by a vertical connecting shaft 10 for free horizontal rotation. The power of the engine 9 is transmitted to the front and rear wheels via a transmission (not shown) for four-wheel drive, and the two vehicle bodies 2 and 3 are connected to the connecting shaft 10 by operating the handle 6. The fuselage 1 is steered by bending it in the horizontal direction via the .

In addition, a seedling planting device 11 is provided in front of the front body 2.
are connected and supported via a support device 12 so as to be movable up and down, and this support device 12 is connected to a lifting device 13.
The seedling planting device 11 is suspended so as to carry the entire load of the seedling planting device 11.

The seedling mounting device 11 includes a main body casing 14,
Three seedling stands 15 are arranged horizontally in each casing and are reciprocally driven by a cross-feeding mechanism (not shown).
A pair of link mechanisms 1 are provided for each seedling table 15.
6, a cylindrical shaft 18 that transmits power to the casing 14, and a bumper 19 connected to the cylindrical shaft 18 and the casing 14. Further, a gear case 20 is provided at the center of the cylinder shaft 18, and the case 20
The power of the engine 9 is transmitted to the input shaft 21 protruding from the input shaft 21, and the power is transmitted to the lateral feed mechanism and the link mechanism 16 to operate the seedling stand 15 and the planting claws 17.

Further, the support device 12 includes a top link 22
and lower links 23, 23 are used, and these links 22, 23,
23 to the front fuselage 2, the main body casing 1
4 to support three points, and the lower link 2
3 and 23, one ends of arms 24 and 24 of the lifting and lowering devices 13 and 13, which will be described later, whose intermediate portions are pivotally supported, are connected in a hanging manner via links 25 and 25.

The lifting and lowering devices 13, 13 use a hydraulic device, and each has a double acting hydraulic cylinder 27 having the arm 24 and a rod 26 connected to the other end of the arm 24, and a 4-port, 3-position, hydraulic cylinder 27.
PR connection/spring center type solenoid switching valve 28
, a flow rate control valve 29 , and a fixed displacement hydraulic pump 3
0, etc., and is attached to the front fuselage 2.

That is, the discharge port of the pump 30 is connected to the pump port P of the switching valve 28 via the flow rate control valve 29, and the two switching ports A and B of the switching valve 28 are connected to chambers on both sides of the piston in the cylinder 27. The return port R of the switching valve 28 and the suction port of the pump 30 are connected to the tank T, and by switching the switching valve 28, the pressure oil of the pump 30 is selectively conducted to both chambers of the cylinder 27, and the arm 24 is connected to the tank T. By driving the lower link 23, the direction of the lower link 23 can be freely changed.

Although not shown in detail in the drawings, the flow rate control valve 29 includes a DC input terminal 31, an electromagnetic coil 32 electrically connected to the terminal 31, and a spool 33. The valve opening is controlled from zero by moving the valve.

Therefore, on both sides of the bumper 19 of the seedling planting device 11, there are detecting devices 34, 34 for detecting the planting surface of the seedlings.
is provided, and the driving of the lifting and lowering devices 13, 13 is controlled by the detection signals from the detection devices 34, 34.

The detection device 34 forms a sled-shaped contact member 35 that contacts the mud surface of the field, and also
One end of the arm 36 is fixed to the front end of the arm 36, the middle part of the arm 36 is pivotally supported on the bumper 19, and the other end facing above the bumper 19 from the pivot part is connected to the bumper 19.
A tension spring 37 is provided between the contact member 35 and the contact member 35 to lightly press the contact member 35 against the mud surface. Further, a resistor 38 is provided at the pivot point of the bumper 19 of the arm 36, as schematically shown in FIG. The resistor 38 connects a single electrical resistance wire 40 wound into a coil inside an insulating case 39 to the arm 36.
Arranged in a circumferential manner around the pivot point of
A movable conductor 41 is provided which is insulated from the arm 36 and rotates together with the arm 36, and the tip of the conductor 41 is pressed against the resistance wire 40 so that it can slide freely.
The detection terminals T, T are pulled out from one end and the conductor 41, and the distance L between the main body casing 14 of the seedling planting device 11 and the seedling planting surface is detected by the electric resistance _R1 between both terminals T, T. It will be accomplished.

Further, a drive control circuit 42 for the lifting device 13 having a detection resistor R ₁ of the detection device 34 is formed, and the output of the circuit 42 is transmitted to the flow rate control valve 29.
The input terminal 31 of and the coil C ₁ of the electromagnetic switching valve 28,
This is done so that it is input to C ₂ .

The drive control circuit 42 includes the detection resistor R ₁ ,
a Wheatstone bridge 43 consisting of a regulating resistor R ₂ , constant resistors R ₃ , R ₄ and a battery E ₁ ;
input terminal and first and second output terminals 44, 45 from
It consists of an amplifier 46 and a switching circuit 47. Then, based on the time when the distance L between the seedling planting device 11 and the seedling planting surface, and therefore the detection resistor _R1 , is at a desired set value, the output of the bridge 43 is adjusted to be zero at the reference time. By adjusting the resistor _R2 , a positive or negative control voltage is outputted from the bridge 43 according to the amount by which the interval L increases or decreases from the set value, and these outputs are amplified by the amplifier 46. This is done to selectively output the amplified positive or negative control voltage from the first or second output terminals 44, 45. Further, the positive or negative control voltage thus output is selectively inputted to the coils C ₁ and C ₂ of the switching valve 28,
Further, the switching circuit 47 always switches the voltage to only positive (or negative) and inputs it to the input terminal 31 of the flow rate control valve 29.

By the way, the lifting device 13 has a cylinder 27.
It is also possible to manually force the operation. That is, the flow control valve 29 in the hydraulic circuit
A switching valve 48 having a coil C ₃ is provided in parallel with the coil C 3 . In addition, a manual changeover switch 49, 49 which is interlocked with each other and has two changeover terminals is formed, and an operation switch in which the movable contact piece 51 can be switched between three positions, a neutral terminal and two changeover terminals, by an operation rod 50. 52, one of the switching terminals of the switching switches 49, 49 is interposed between the two output lines of the amplifier 46, and each switching terminal of the operation switch 52 is connected to the other switching terminal. , and a battery E ₂ is connected between the movable contact piece 51 and the ground, and
Although not shown, both switching terminals of the operating switch 52 are connected to the coil _C3 .

In addition, 53 is a spare seedling stand installed in the rear fuselage 3;
4 is a relief valve.

Therefore, in the above configuration, when performing rice planting operation, if the distance L between the main body casing 14 of the seedling transplanting device 11 and the seedling planting surface, and thus the detection resistance R ₁ is at the desired setting value, The control voltage output from the amplifier 46 becomes zero, and the flow control valve 29
The valve opening is controlled to zero, the switching valve 28 is turned off, the rod 26 of the cylinder 27 is held at the set protrusion amount, and the seedling planting device 11 is suspended by the arm 24 and placed on the seedling planting surface. The distance L between the two is maintained at the set value.

Further, when the distance L between the main body casing 14 and the planting surface increases or decreases from the set value, the first and second output terminals 44 and 45 of the amplifier 46 A control voltage is selectively outputted from the switching valve 28, and the coil _C1 or _C2 is excited to switch the switching valve 28, and the opening degree of the flow rate control valve 29 is opened in accordance with the control voltage.
In this way, oil with a flow rate corresponding to the control voltage selectively flows into the chambers on both sides of the piston of the cylinder 27, the amount of protrusion of the rod 26 is decreased or increased from the set value, and the arm 24 is moved counterclockwise or clockwise. being swayed,
The lower link 23 moves up and down, and the distance L is controlled to a set value.

Therefore, during rice planting operation, if the interval L increases or decreases by a small amount from the set value, the switching valve 28 is instantaneously switched in response to the increase or decrease, but at this time the flow rate control valve 29 , the valve opening is controlled from zero to a small valve opening commensurate with the small increase or decrease, and a small amount of oil selectively flows into one of the chambers on both sides of the piston of the cylinder 27, and the rod 26 is relatively By moving slowly and accurately by an amount commensurate with the small increase or decrease, the distance L can be adjusted accurately without so-called excessive control.

Further, when the interval L increases or decreases significantly from the set value, the switching valve 28 is switched in accordance with the increase or decrease, and the flow control valve 29 changes the valve opening degree from zero to the aforementioned significant increase or decrease. The valve opening is immediately controlled to a large degree commensurate with the weight loss, a large amount of oil selectively flows into one of the chambers on both sides of the piston of the cylinder 27, and the rod 26 responds well over a travel distance commensurate with the large increase and weight loss. The distance L can be controlled to the set value immediately by being moved reliably.

That is, during rice planting operation, no matter how much the distance L changes from the set value, the rod can be reliably moved by the amount of movement commensurate with the amount of change, and the distance L can be reliably controlled to the set value. .

In addition, when rice transplanting operation is performed, the amount of seedlings on the seedling platform 15... decreases and the weight gradually decreases, and the seedling platform 15...
Although the center of gravity applied to the main body casing 14 constantly fluctuates in the lateral direction due to the lateral feeding of the seedling planting device 11, since the entire load of the seedling planting device 11 is carried by the lifting device 13, the distance L does not fluctuate due to the fluctuation. Instead, the interval L is always kept at the set value.

Furthermore, even if the intervals L, L on both sides of the main body casing 14 change rapidly, the detection device 3
4 and 34, each of these changes is detected, and each lifting device 13, 13 is controlled separately,
The distances L and L are controlled to set values, and the so-called main casing 14 is controlled in such a way that it tilts laterally and is always parallel to the mud surface.

Further, even if the front wheels 4, 4 fall into a deep place or run up on a high place, and the distances L, L change suddenly, the seedling planting device 11 will not be able to move the lifting device 1.
3 and 13, the attitude is immediately controlled, and the distances L and L are both controlled to set values.

Therefore, the seedlings planted by each planting claw 16 can always be planted at a constant depth on the mud surface of the field.

Moreover, since the detection devices 34, 34 detect the planting surface using the contact members 35, 35 that lightly press against the mud surface, the mud will not be pressed even when running at high speed, and high-speed planting is possible. be.

Furthermore, when performing the rice transplanting operation as described above, if it becomes necessary to lift the seedling transplanting device 11 high or lower it back to its original position, this can be easily done by operating the operating switch 52 and operating rod 50. .

In addition, the planting depth of seedlings can be freely changed using the adjustment resistance _R2 .

In the above explanation, two cylinders 27 are used, but the number may be increased or decreased as appropriate.
4 is provided on the bumper 19, but it may be provided at any arbitrary location on the seedling planting device 11 or the body 1.

In addition, in the above explanation, the detection device 34 for the seedling planting surface
As shown in FIG. When a light beam is projected from a light emitting part onto a seedling planting surface, reflected by the surface, and received by a light receiving part, a device configured to detect the projection angle may also be used. A sensor is used to detect the time it takes for ultrasonic waves to reflect off the seedling planting surface and return, and a capacitive sensor is used to detect the capacitance between the seedling planting surface and the seedling planting surface. You may also use the one you prefer.

As described above, the present invention supports the seedling planting device on the machine body via the support device so that it can move freely up and down, and is suspended by the lifting device to carry the entire load. A detection device for detecting the planting surface of the seedlings is provided, and the drive of the lifting device is controlled by the detection signal from the device. Planting is no longer affected by changes in surface hardness or planting speed, and is no longer affected by changes in the center of gravity due to a decrease in the amount of seedlings on the seedling platform or by horizontal movement of the seedling platform. It is possible to always accurately detect the distance between the seedling planting device and the planting surface regardless of the planting speed, and to reliably control the drive of the seedling planting device by the lifting device to always maintain the distance as set. Now possible, with a certain planting depth,
Moreover, since it is not equipped with a float, the mud pushing caused by the float can be eliminated, and rice planting can be carried out at high speed without disturbing the planted seedlings.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the present invention, Fig. 2 is a partially enlarged front view thereof, and Fig. 3 is an explanatory diagram combining an electric circuit and a hydraulic circuit to explain drive control of a lifting device. be. DESCRIPTION OF SYMBOLS 1... Airframe, 11... Seedling planting device, 12... Support device, 13... Lifting device, 34... Detecting device.

Claims (1)

[Claims] 1 The seedling planting device is connected and supported by the machine body via a support device so as to be movable up and down, and this support device is suspended by a lifting device to carry the entire load of the seedling planting device, while the machine body A rice transplanter characterized in that a detection device for detecting a planting surface of seedlings is provided in either of the rice transplanter and the seedling planting device, and the drive of the lifting device is controlled by a detection signal from the detection device.