JPH03149404A - hydraulic system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a hydraulic device that moves a hydraulic piston forward and backward with respect to a hydraulic cylinder. [Prior Art and its Problems] As a prior art of this type, In order to move the hydraulic piston forward and backward with respect to the hydraulic cylinder, two oil passages are provided,
There is a system in which the speed of movement of the hydraulic piston relative to the hydraulic cylinder is changed between advancing and retracting, but this structure is extremely complex and expensive.

[Means to solve the problem]

In order to solve the problems of the prior art described above, this invention replaces the hydraulic piston 23g with the hydraulic cylinder 23f.
An automatic flow rate regulator 2 that reduces the flow rate of pressure oil to one side relative to the other side in an oil passage that is moved forward and backward.
This is a hydraulic system equipped with 33.

〔Effect of the invention〕

This invention connects the hydraulic piston 23g to the hydraulic cylinder 23.
It has an extremely simple configuration because an automatic flow rate regulator 23g is provided in the oil passage that moves the pressure oil forward and backward with respect to f, which reduces the flow rate of the pressure oil to one side compared to the flow rate to the other side. The moving speed of the hydraulic piston 23g relative to the hydraulic cylinder 23f can be changed between advancing and retracting.

〔Example〕

About a walking rice transplanter which is an embodiment of the present invention.

This will be explained in detail below.

Reference numeral 1 designates a traveling mission case, and the front end of a cylindrical front frame 4 extending rearward is fixed to the rear side surface with bolts.

2 is a planting transmission case constructed by connecting a central case body 2a and left and right case bodies 2b with a cylindrical case body 2c, and the lower front side of the central case body 2a is connected to the rear end of the front frame 4. It is fixed with a bolt. And, on both sides of the lower part of the central case body 2a and inside each of the left and right case bodies 2b, 2b,
A seedling planting fixture 9 that moves up and down to take out seedlings one by one from a seedling stand 50 to be described later and plant them in the field is mounted on a rotating crank and a swing arm.

Reference numeral 10 denotes a control handle, which is attached to the upper end of a rear frame 4' whose front end is fixed with bolts to the lower rear side surface of the central case body 2a.

Reference numeral 11 denotes an engine, which is fixedly connected to the front part of the running midgemin case 1 with bolts.

12 and 13 are left and right running wheels, running mission case 1
The left and right chain cases 18 and 19 are rotatably attached to bosses 16 and 17 that surround the left and right drive shafts 14 and 15 that protrude from both sides. It is provided. 21・22
are left and right arms that are integrally provided with the bosses 16 and 17 that are provided integrally with the left and right chain cases 18 and 19, respectively.

Reference numeral 7 denotes a hydraulic device comprising a hydraulic cylinder 5 and a hydraulic piston 6 for vertically moving the left and right running wheels 12 and 13.

The base of the hydraulic cylinder 5 is fixed with bolts to the lower rear side surface of the hydraulic case 40 which is fixed with bolts to the surface of the running midgemin case.
The rear end portion is fixed to the upper part of the front support frame 3a, which has a U-shape in plan view and whose lower part is fixed to the front frame 4, with bolts VII. The left and right center portions of a balance device 23 whose front ends are connected to the upper ends of the left and right arms 21 and 22 are pivoted to the rear end portion of the hydraulic screw 1-6 so as to be freely rotatable about #124 vertically. , the left and right running wheels 12 and 13 are configured to move up and down in a contradictory manner.

The balance device 23 has a balance body 23a whose left and right center portions are rotatably supported on the tip of the hydraulic piston 6 by a vertical shaft 24.
and left and right connecting rods 23d and 23e rotatably mounted on the left and right sides of the heavenly body 23a about vertical shafts 23b and 23e.
It is composed of.

The left and right rods 23d and 238 are connected to the left and right arms 21 and 238, respectively.
It is rotatably pivoted to the upper end of 22.

The left rod 23d has a hydraulic cylinder 23f and a hydraulic piston 23. A rolling hydraulic device 23h consisting of a hydraulic piston 23g is provided.
The left rod 2 due to the crowd for the hydraulic cylinder 23f.
3d is configured so that the length of the hydraulic piston 6 can be changed.Here, to explain in more detail the configuration of the rear part of the hydraulic piston 6, the diameter of the rear part of the hydraulic piston 6 is made slightly thinner and a stepped part is formed in the middle part. Then, a stopper washer 41 is applied to the step, a buffer spring 42 is installed between the washer 41 and the receiving member 8, and a stopper washer 44 is attached to the rear end of the hydraulic piston 6 with a bolt 43. Fixed. The receiving member 8 is fitted into the hydraulic piston 6 so as to be slidable in the longitudinal direction of the hydraulic piston 6, and a fitting hole 8a formed at the lower part of the receiving member 8 is fitted onto the guide member 3b described below to prevent rotation around the hydraulic piston 6. is configured to be blocked. Of course.

Since the balance body 23a is rotatably attached to the receiving member 8 about the vertical shaft 24, the balance device 23 can move in the longitudinal direction of the aircraft and rotate around the vertical shaft 24, but it can be moved by hydraulic pressure. It is configured so that the rotation 11+ around the piston 6 does not occur.

The guide member 3b is formed of a round steel bar, and its front part is fixed to the upper part of the front support frame 3a, and its rear part is fixed to the front frame 4.
After the lower part is fixed to the support frame 3C, the lower part is fixed to the upper part of the support frame 3C. The front frame 4, the guide member 3b, the front support frame 3a and the rear support frame 3c form a closed rectangular strong support frame, and the guide member 3b supports the tip of the hydraulic piston 6 via the receiving member 8. It is configured to support.

Therefore, in the hydraulic device 7, the rear end of the hydraulic cylinder 50 is supported by the front support frame 3a, and the tip (rear end) of the hydraulic piston 6 is supported by the guide member 3b. Since a large force does not act on the connecting and fixing part with the base, the hydraulic case 40 and the hydraulic cylinder 5 do not need to be strong, and can be formed of a lightweight case made of aluminum with low wall thickness.

The seedling platform 50 is connected via left and right connectors 26 and 27 to a movable rod 25 that reciprocates left and right by a left and right reciprocating mechanism in the planting transmission case 2, and is connected to the rear frame 4 which is tilted backward and vertically. Above the handle 10, it is supported by vertical support devices 28 and 29 so as to be able to reciprocate from side to side. In addition, the lower support device 29 is integrally formed with a seedling support frame 29a that receives and slides on the lower side of the seedling placed on the seedling stand 50, and has a crescent shape when viewed from the side. The support frame 29a is provided with four seedling dividing openings, and the seedling dividing claws 9a of the seedling planting tool 9 intervene from above into the seedling dividing openings to separate one seedling from the seedling stand 50. It is configured to take out one by one.

A bumper 30 is fixed to both the engine 11 and the traveling transmission case 1 and has a U-shape in plan view.

Reference numerals 31, 32, and 33 are a central leveling float and left and right leveling floats, respectively.The rear portions of each float are supported by shafts 34 and 34, and the front portions are supported by support fittings 31a and 3 fixed on the upper surface of each float.
2a, 33a and the elongated holes 35b of the floating links 35... are connected by pivot pins, so that they are supported in a vertically movable manner.

Reference numeral 36 denotes a pitching hydraulic valve that sends the pressure oil pumped out from inside the traveling mission case 1 by the hydraulic pump 37 to the hydraulic cylinder 5 and returns the pressure oil from the hydraulic cylinder 5 to the inside of the traveling mission case 1. It is provided inside the case 40, and its switching lever 36a is connected to the upper surface of the front part of the central grading float 31 by a rod 36b. The hydraulic valve 36 is configured to be switched.

38 is a hydraulic valve for rolling, and the hydraulic case 4
0, and is used to send pressure oil from the hydraulic bomb 37 to the rolling hydraulic cylinder 23f of the suspension device 23, and to return pressure oil from the hydraulic cylinder 23f into the traveling mission case 1. Linkage switching mechanism 3
9 is connected to the front parts of the left and right leveling floats 32 and 43.

The rolling hydraulic valve 38 is configured to be switched when the difference in vertical movement of the front portions of the left and right leveling floats 32 and 33 exceeds an appropriate range.

Here, the configuration of the linkage switching mechanism 39 will be described.

The bases of left and right pipe materials 48 and 49 are fixed to the left and right sides of the traveling transmission case 1.
・Left and right support rods 51 and 52 are provided so as to pass through the inside of 49.

The bases of the floating links 35, 35 formed of cast aluminum are rotatably supported at the tips of the left and right support rods 51, 52.

Reference numerals 53 and 54 are connectors with left and right adjustment devices made of thick iron plates, and their bases are fixed to the shaft ends of left and right support rods 51 and 52, respectively, with bolts 51a and 52a, and each of them has left and right support rods 51 and 52, respectively. It is provided to rotate together with the rods 51 and 52.

The distal ends of the left and right adjusting device connecting devices 53 and 54 are formed into a U-shape, and the floating links 35 and 35 are inserted into the U-shape, respectively, so that the rotation adjusting devices 53a and 54a can be connected to each other. The screw portions 53b and 54b are inserted into the screw holes 35a and 35a of the floating links 35 and 35, respectively. Furthermore, 53c/54
c is a lock bolt, and 53d-54d are spring washers.

However, when the VA movement adjusters 53a, 54a and the rotation are adjusted, the left and right swing links 35, 35 are adjusted to move in the vertical direction with respect to the left and right adjustment device connecting devices 53, 54. Idle link 35/35
The installation is configured so that the posture can be changed, and when the left and right leveling floats 32 and 33 move up and down, the left and right support rods 51 are attached via floating links 35 and 35 and connectors 53 and 54 with left and right adjustment devices. - 52 is provided so that it can rotate in the E direction. In addition, the connectors 53-54 with left and right adjustment devices are
It is provided so as to be located outside the floating links 35, 35, so as to protect the aluminum floating links 35, 35.

Reference numerals 55 and 56 denote left and right interlocking arms, the bases of which are fixed to the bases of the left and right support rods 51 and 52, respectively, and are provided to protrude from the notches 1a-la of the traveling transmission case l, respectively.

57 and 58 have left and right interlocking arms 55 and 5 at their lower ends, respectively.
The right rod is inserted into engagement holes 55a and 56a formed at the rear end of the balance body 59, and its upper end is slidably inserted into left and right cylindrical bodies 60 and 61 fixed to both left and right ends of the balance body 59, respectively. It is provided. 62a and 63a are lower springs provided externally to the left and right rods 57 and 58, respectively,
The lower end is a catch seat 57 fixed to the left and right rods 57 and 58, respectively.
b, 58b, and the upper ends thereof are the left and right cylinders 6 of the balance body 59.
It is provided in contact with the lower surface of 0.61.

62b and 63b are upper springs that are fitted onto the left and right rods 57 and 58, respectively, and their upper ends are attached to the left and right rods 57 and 58, respectively.
The lower ends thereof are provided in contact with the upper surfaces of the left and right cylindrical bodies 60 and 61 of the balance body 59, and are in contact with the seats 57c and 58c fixed to the balance body 58, respectively. And these springs 62a, 63a,
The vertical movement of the left and right interlocking arms 55 and 56 is transmitted to the balance body 59 via 62b and 63b. The balance body 59 has a cooperating shaft 64 fixed in its center, and the rotary shaft 6
4 is inserted into a cylindrical body 65 fixed to the valve case 40, and the lower end of a swing arm 66 is fixed to the tip thereof. and,
The upper end of the swing arm 66 is connected to the rolling hydraulic valve 38.
is engaged with the tip of the spool 38a, and the balance body 59
When the spool 38a rotates about the rotation axis G4FA, the spool 38a is configured to be switched to the lower direction.

However, due to the upward movement of the left and right leveling floats 32 and 33, the rolling hydraulic valve 38 is switched by each of the above members, but when both the left and right leveling floats 32 and 33 move upward by the same amount.

Left and right springs 62a, 63a, 6 are provided on both the left and right sides of the balance body 59.
Since the same force acts through 2b and 63b, the balance body 5
9 does not rotate and the rolling hydraulic valve 38 cannot be switched.If there is a difference in the amount of upward movement of the left and right soil leveling floats 32 and 33, for example, if the left leveling float 32 has a larger amount of upward movement, the balance body 59 As the force pushing up the left side increases, the rolling hydraulic valve 38 removes pressure oil from the front chamber 23f of the rolling hydraulic cylinder 23f, and releases the pressure oil from the rear chamber 23f.
Pressure oil is sent to the left connecting rod 23d to shorten the length of the left connecting rod 23d, and the left running wheel 12 is switched to the downward movement side. On the other hand, if the right leveling float 33 has a larger upward movement, the force pushing up the right side of the balance body 59 will increase, and the rolling hydraulic valve 38 will cause the rolling hydraulic cylinder 2 to move upward.
The configuration is such that pressure oil is sent to the front chamber 23f1 of 3f, pressure oil is removed from the rear chamber 23f3, the length of the left connecting rod 23d is lengthened, and the left traveling wheel 12 can be switched to the side that moves upward.

Here, the configuration of the hydraulic cylinder 23f of the rolling hydraulic system ""iR23h will be explained in more detail based on the second W4. 231 and 23j are cuffs for supplying and discharging pressure oil, and are provided on the side walls of the cylindrical cavity 23. Reference numeral 23m denotes a mover provided to be able to slide inside the cavity 23, and when pressure oil is supplied from the oil row 23j, it moves upward under the pressure of the pressure oil and moves the ball 2.
3n is pushed up against the spring 23p to open the oil passage 23q. 23r is an oil passage pipe connecting the cuff 23i and the cuff chamber 23f□. 23S is a hexagonal pillar-shaped mover as an automatic flow rate regulator provided so as to be able to slide inside the cylindrical cavity 23,
The space between the outer surface and the cavity 23t is configured to allow oil to move freely, and a throttle oil passage 23s' is also formed inside the space.

However, the front chamber 23 of the rolling hydraulic cylinder 23f
When the pressure oil of f1 is removed and pressure oil is sent to the rear chamber 23ft to shorten the length of the left connecting rod 23d and move the left running wheel 12 downward, pressure oil is supplied to the cuff 23i, and the pressure oil is supplied to the cuff 23i. The ball 23n is pushed up against the spring 23p and the oil passage 2
3 (1 is connected. Then, the pressure oil flows through the oil passage pipe 23r.
Push the mover 23g backward through the
The oil is supplied to the rear chamber 23f through the outside and inside throttle oil passages 2:l1g, and moves the hydraulic piston 23K forward. At this time, the oil in the front chamber 23f4 is discharged from the cuff 23j. Therefore, since the pressure oil is supplied to the rear chamber 23f3 through the outside of the mover 23S, the left running wheel 12 can be moved down quickly.

Conversely, the rear chamber 23f of the rolling hydraulic cylinder 23f
When removing the pressure oil from the cuff 23j and feeding pressure oil into the front chamber 23f1 to increase the length of the left connecting rod 23d and moving the left traveling wheel 12 upward, the pressure oil supplied from the cuff 23j is transferred to the front chamber 23f.
1, the hydraulic piston 23g is moved backward, the mover 23m is moved upward, and the ball 23n is moved to the spring 23P.
Push up against the pressure to open oil passage 23q. Then, the hydraulic piston 23g tries to move rearward, so the rear chamber 2
The pressure of 3f2 increases and pushes the mover 23g forward and the front part of the mover 23s comes into close contact with the wall surface, so the discharged oil is transferred to the mover 2.
The oil in the rear chamber 23f8 is discharged from the program 23i only through the throttle oil passage 23s'' of the slider 23s. The left running wheel 12 slowly moves upward.

Reference numerals 32b to 33b are sensitivity adjustment forces integrally formed by extending the support fittings 32a and 33a forward. 32 is moved upward so that when the top surface of the sensitivity adjustment marker 32b and the top surface of the floating link 35 match in the vertical direction, the rotation adjustment tool 53a is switched so that 38 is switched and the left traveling wheel 12 starts to move downward. The time of adjustment is the standard sensitivity of the left leveling float 32, and. With the left and right leveling floats 32 and 33 suspended in the air, when the right leveling float 33 is moved upward and the top surface of the sensitivity adjustment marker 33b matches the top surface of the floating link 35 in the vertical direction, 38 is switched. The configuration is such that the standard sensitivity of the right leveling float 33 is set when the rotation adjuster 54a is adjusted so that the left running wheel 12 starts to move upward.

Reference numeral 67 denotes a hydraulic lever for manually switching the pitching hydraulic valve 36, which is connected to the switching lever 36a of the pitching hydraulic valve 36 via an operating wire 68, and is configured to be operable in the 2-1 direction. has been done.

When this hydraulic lever 67 is operated in two directions, the pitching hydraulic valve 36 enters an automatic control state that is switched by the vertical movement of the central leveling float 31. When the hydraulic lever 67 is operated in the E direction, the pitching hydraulic valve 36 is moved from the hydraulic cylinder 5 to the hydraulic piston. 6 extends rearward, and the left and right wheels 12 and 13 are switched to the side where they both descend.

69 is a clutch lever for planting, and a hydraulic lever 67
Similarly, when the hoe is operated in two directions, the clutch is connected for planting in the planting transmission case 2, and the seedling planting tool 9 reciprocates up and down, and the seedling platform 50 reciprocates left and right. However, when the clutch is operated in the E direction, the clutch is disengaged and the seedling planting tools 9 and the seedling stand 50 are stopped.

Reference numeral 45 denotes a transmission shaft, which is provided to transmit power from the traveling transmission case 1 to the planting transmission case 2.

46 is a bonnet that flies over the top of the aircraft, and 47 is a spare seedling stand.

Here, the preliminary seedling mounting table 47 will be explained in detail.

Reference numerals 80 and 80 are left and right guide rails made of pipe steel, the front and rear ends of which are fixed to the fuselage.
The left and right guide rail sections 80a-QOa are formed in an inclined shape with a lower front end and a higher back end, and left and right guide rollers aob and 80b are provided at the rear ends of the guide rail sections 80a and 80a.

Note that 80c is a stopper that stops the moving table 81 described later from moving forward, and 80d is a stopper that stops the moving table 81 described later from moving backward.

Reference numeral 81 denotes a moving table, and the left and right guide rail portions 80a and 81 are movable tables.
Left and right upper and lower rollers 81a and 8 engage with 80a from above and below.
1a, and the left and right rail portions 81b and 81b guided by the left and right guide rollers 80b and 80b, and the left and right rail portions 81b.
・Front and rear horizontal frames 81c and 81e that connect and fix 81b
It is composed of. The horizontal frame 81c on the rear side of the body is provided with three locking holes 81d, and the base of the grip handle 81θ is fixed thereto.

Reference numeral 82 denotes a preliminary seedling mounting section, which is connected to the horizontal frames 81c and 8.
Front and rear lower frames 82a, 82a have engagement grooves formed to be able to slide left and right by engaging with the front and rear frames 82a, and a vertical frame 8 whose base is fixed to the front and rear lower frames 82a, 82a.
2b, 82b and connecting plates 82c, 82c that connect the upper parts of the vertical frames 82b, 82b, and a picture frame 82d made of an iron rod that supports the preliminary seedlings.
. is fixed on the lower frame 82a and the connecting plate 82c. In addition, 82e is a fixed bottle,
The locking hole 81d provided in the horizontal frame 81c...
By engaging with , the preliminary seedling platform 82 can be fixed at the center position on the left and right sides of the machine body and at positions offset to the left and right.

When the holding handle 81a is held and pulled toward the rear of the machine, the spare seedling platform 47 moves toward the rear of the machine along the left and right guide rails 80, making it easy to take in and take out seedlings. Therefore, an operator who is doing rice planting work behind the control handle 10 can easily place seedlings on the preliminary seedling platform 47 or take seedlings from the preliminary seedling platform 47 and place them on the seedling platform. 50
It can be supplied to When the seedling supply work is finished, hold the grip handle 81a and push the machine forward again to move the spare seedling platform 47 to the left and right guide rails 80 and 8.
0 to the front of the aircraft, making it easy to maneuver the aircraft with good visibility in front of the aircraft.

Reference numeral 90 denotes a fertilization device, which includes a middle fertilization tank 90a and a left and right fertilization tank 90 provided below the preliminary seedling platform 47.
b, 90c, a trencher 90d provided in the lateral vicinity of the front of the seedling planting position of the central soil leveling float 31 and left and right leveling floats 32, 33, a middle fertilizer tank 90a, and a left and right fertilizer tank. The granular fertilizer metering feed device 90θ provided at the bottom of the 90b and 90c, respectively, and each of the above-mentioned groove cultivators 9
0d...-, and a fertilization pipe 90f that connects between. In addition, 1! is placed on the top of the middle fertilizer tank 90a and the left and right fertilizer tanks 90b and 90c. i body 90K...
・ are each provided so that they can be opened and closed with hinges 90h. Then, a bin 82e for fixing the preliminary seedling mounting stand 47 is provided.
from the locking hole 81d in the center, move the spare seedling resting part 82 to a position offset to the left and right of the machine body, insert the bottle 82e into the locking hole 81d provided on the left and right, and insert the preliminary seedling resting part 82.
is fixed in a position offset to the left and right. Then, there will be no preliminary seedling mounting section 82 above either the middle fertilizer tank 90a or the left and right fertilizer tanks 90b and 90c, so open each lid 90g of the fertilizer tank and enter the tank. can be easily supplemented with granular fertilizer. Once the fertilizer has been replenished, the preliminary seedling loading section 82 is again moved to the center position of the machine and fixed. This ensures that the left-right balance of the machine is good, allowing seedling planting work to be carried out with good running performance of the machine. can.

Reference numerals 70 and 71 are left and right seedling markers for adjusting the distance between the machine body and the already planted seedlings. Red synthetic resin balls 70a and 71a are fixed to one end of each, and a coiled spring part 70b is attached to the middle part.
- 71b is formed, and locking portions 70c and 71c are provided at the other end. And each coiled spring part 70b, 71b
With the bolts 72 and 72 passed through the left and right leveling floats 3
It penetrates through 2 and 33 and is fixed with nuts 73... Locking projections 74 and 75 are integrally formed on the upper surfaces of the left and right leveling floats 32-33, respectively, and by locking the locking portions 70c and 71c with the locking projections 74 and 75, the left and right The configuration is such that the positions of seedling markers 70 and 71 can be set. and.

Since the coiled spring parts 70b and 71b are formed in the middle, when the balls 70a and 71a hit another hard object, the balls 70a and 71a move to retreat due to their elasticity, preventing them from breaking. It can be prevented.

Reference numerals 76 and 77 are left and right line drawing markers, which are used to draw lines on the field scene at the positions where the left and right centers of the machine body pass through in the next step.

Reference numeral 78 is a center marker, which is used by the operator to steer the aircraft in accordance with the line drawn on the field scene by the left and right line markers 76 and 77.

After putting the walk-behind rice transplanter with the configuration shown above into the paddy field, granular fertilizer is put into the middle fertilizer tank 90a and left and right fertilizer tanks 9ob and 90c, and the seedlings are placed on the preliminary seedling stand 47 and the seedling stand 50. affl is accommodated and each rotating part is driven by the engine 11, the rotation of the running wheels 12 and 13 propels the aircraft with the central leveling float 31 and left and right leveling floats 32 and 33 in contact with the soil surface of the paddy field.

When the seedling planting clutch lever is driven in two directions, the seedling planting tools 9 arranged in parallel in the left and right directions move vertically in an elliptical planting trajectory, and are reciprocated left and right. The seedlings on the seedling platform 50 are divided one by one through the seedling dividing opening and are successively planted on the soil surface leveled by the respective soil leveling floats 31, 32, and 33.

At this time, the granular fertilizer is applied to each fertilizer tank 90a, 90b, 9.
A fixed amount of granular fertilizer is dispensed from 0c by a fixed quantity dispensing device 90e, and is embedded in a groove formed on the side of the seedlings to be planted in the field by each trencher 90d, and the seedlings are planted. The work and fertilization work are carried out at the same time.

Next, during such seedling planting work, the hydraulic lever 6
7 in two directions, the left and right traveling wheels 12 and 13 are automatically controlled to move up and down when the plowing surface changes, such as becoming shallower or deeper.

The control state at that time will be explained in detail below.

First, when the plowing platform becomes deeper in the front-rear direction, the left and right traveling wheels 12 and 13 sink deeper from the soil surface, so that the soil leveling floats 31, 32, and 33 are all pushed upward. When the central leveling float 31 reaches a certain level (when it is pushed up towards the machine body beyond the appropriate range for seedling planting work), the switching lever 3 of the hydraulic switching valve 36
6a is switched from the central leveling float 31 via the rod 36b to the side from which the piston 6 of the hydraulic device 7 projects, so that the piston 9. Tenryo device 23. Left and right arm 2
1・22. The left and right running wheels 12 and 13 are moved down via chain cases 18 and 19.

Then, the traveling wheels 12 and 13 gradually come into strong contact with the tiller, and the aircraft floats up.

When the ground pressure of each of the ground leveling floats 31, 32, and 33 decreases to a proper state, the hydraulic switching valve 36 becomes a neutral state, and the downward movement of the traveling wheels 12, 13 is stopped.

When the tiller becomes shallower in the front-rear direction, the situation is the opposite of the above, and the soil leveling floats 31, 32, and 33 tend to float and move downward from the machine body, so the switching lever 36a is switched and the piston 6 is retracted into the hydraulic cylinder 5. In rare cases, the traveling wheels 12 and 13 move upward. Then, when a proper grounding condition is achieved, the hydraulic switching valve 36 returns to neutral. Therefore, the left and right running wheels 12 and 13 move up and down in response to changes in the depth of the tiller, so that the seedlings are always planted at the appropriate depth.

In addition, if there is little difference in the depth of the tiller in the front and back direction of the machine,
Due to the action of the buffer spring 42 attached to the piston 6, the left and right traveling wheels 12 and 13 simultaneously move up and down, thereby maintaining the aircraft body in a proper state. That is, when the depth of the tiller changes in the longitudinal direction of the machine body to an extent that cannot be corrected by the buffer spring 42, the pitching control device is activated.

Next, let us explain the case where the plow depth is different on the left and right sides. First, when the left side is deeper and the right side is shallower.

Naturally, the aircraft will lean to the left with the grounding point of the right running wheel 13 as the origin. Then, the left leveling float 3
The ground pressure of the right ground leveling float 33 becomes larger than that of the right leveling float 33, causing it to move upward, and conversely, the right leveling float 33 moves downward. Therefore, the rolling hydraulic valve 38 is switched, pressure oil is removed from the front chamber 23f1 of the rolling hydraulic cylinder 23f, and pressure oil is sent to the rear chamber 23f, and the left connecting rod 23d.
Since the length of is shortened, the left traveling wheel 12 is moved downward.

Then, when the body is in a proper state with respect to the mud surface, the rolling hydraulic valve 38 becomes neutral.

Further, when the left tiller is shallow and the right tiller is deep, the machine body leans to the right with the grounding point of the left traveling wheel 12 as the origin. Then, the ground pressure of the right leveling float 33 becomes greater than the grounding pressure of the left leveling foot 32 and moves upward, and conversely, the left leveling float 32 moves downward. Therefore, the rolling hydraulic valve 38 is switched and pressure oil is sent to the front chamber 23f1 of the rolling hydraulic cylinder 23f and the rear chamber 23f.
Since the pressure oil No. 3 is removed and the length of the left connecting rod 23d becomes longer, the left traveling wheel 12 is moved upward. Then, when the body is in a proper state with respect to the mud surface, the rolling hydraulic valve 38 becomes neutral. Therefore, the left running wheel 12 moves up and down in response to changes in the depth of the tiller in the left-right direction of the machine body, so that the seedlings are always planted at an appropriate depth. In addition, since a slider 23s with an automatic throttling action is provided in the oil path of the hydraulic cylinder 23f that moves this left running wheel 12 up and down, the up and down movement of this left running wheel 12 is faster than the downward movement. The movement becomes slower and proper rolling control is achieved.

In addition, if there is little difference in the depth of the tiller in the left and right direction of the machine,
Due to the action of the balance device 23, the left and right traveling wheels 12 and 13 move up and down in a contradistinct manner, and the aircraft body is maintained in a proper state. That is,
When there is a difference in the depth of the tiller in the left-right direction of the machine to an extent that cannot be corrected by the balance device 23, the rolling control device is activated.

The rolling control device exhibits better running performance when its operating sensitivity is adjusted according to field conditions (hardness), but this sensitivity adjustment can be done by using the left and right rotation adjusters 53a and 54a. This can be easily done by simply adjusting the rotation, allowing for appropriate sensitivity adjustment. Also, when adjusting the sensitivity, the sensitivity can be adjusted very easily if the adjusting operation is performed while observing the positional relationship between the top surface of the tips of the hs variable adjustment markers 32b and 33b and the top surface of the floating link 35. Furthermore, the connectors 53 and 54 with left and right adjustment devices.

Since it is provided so as to be located outside the floating links 35, 35, the aluminum floating links 35, 35 can be protected.

[Brief explanation of the drawing]

The figures show a walk-behind rice transplanter which is an embodiment of the present invention. Figure 1 is a side view, Figure 2 is a plan view of main parts, and Figure 3
Fig. 4 is a side view of the main part, Fig. 5 is a rear view of the main part, Fig. 6 is a hydraulic circuit diagram, Fig. 7 is a partially sectional side view of the main part, and Fig. 8 is A of Fig. 7. It is an arrow sectional view. In the figure, symbols 12 and 13 are left and right running wheels, 23° is a hydraulic piston, 23f is a hydraulic cylinder, and 235 is an automatic flow rate regulator.

Claims (1)

[Claims] (1) An automatic flow rate regulator 23s that reduces the flow rate of pressurized oil to one side relative to the flow rate to the other side in the oil passage that moves the hydraulic piston 23g back and forth with respect to the hydraulic cylinder 23f.
Hydraulic system equipped with.