JPH0310805Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a horizontal control mechanism for a rice transplanter equipped with a hydraulic cylinder for rolling control that follows the planting field and maintains the planting area horizontally.

"Prior Art" Conventionally, a closed center type hydraulic switching valve has been used to control the operation of this hydraulic cylinder, and when this hydraulic switching valve is in a neutral position, the hydraulic cylinder is held fixed at that state position. be done.

``Problem that the invention seeks to solve'' For this reason, the neutral range of the hydraulic switching valve becomes a dead zone, and even if the planting area is tilted from side to side, it will not be adjusted horizontally and will remain tilted. However, there were drawbacks such as variations in planting depth between the left and right sides. Another method to solve this problem was to eliminate the neutral range of the switching valve, but this had the disadvantage of being too sensitive and causing hunting phenomena, making it impractical.

"Means for Solving the Problem" Therefore, the present invention provides an open center type hydraulic switching valve for controlling the operation of the double-acting hydraulic cylinder for rolling control, and when the switching valve is in the neutral position, the cylinder It is configured so that it is in a free operating state.

"Function" According to the present invention, when a small inclination from left to right occurs in the planting part within the neutral range of the switching valve, the cylinder freely expands and contracts to support the buoyancy of the float and the float. The horizontality of the planting area is maintained by the restoring force of the link, and therefore, regardless of whether the neutral range of the switching valve is wide or narrow, stable planting work can be performed with a constant planting depth.

"Embodiment" An embodiment of the present invention will be described below in detail based on the drawings.

Figure 1 is a hydraulic circuit diagram showing the main parts, Figure 2 is a side view of the whole, and Figure 3 is a plan view of the same. In the figure, 1 is the engine, 2 is the transmission case, 3 is the planting transmission case, 4 is a planting drive case; 5 is a paddy wheel supported on both sides of the transmission case 2 via a swing case 6; 7 is the engine 1 and each case 2;
10 is a steering handle connected to the rear end of the drive case 4, and 11 is a float that supports the fuselage via a support ring 8 and a buffer member 9; and a seedling stand for two rows of low front and rear height of the planting part 13 which is provided along the upper part of the handle 10 and reciprocated from side to side; 14 is a seedling stand which is attached to the drive case 4 via the planting arm 15; 11 is a planting claw for taking out and planting one seedling; 16, 16 is the float 7;
Left and right ground pressure detection floats are rolling sensors installed on both sides of the front of the float 7, and 17 is a pitching sensor installed on the top surface of the float 7, which is a roller for detecting the height of the support for the aircraft. The structure is such that the seedlings are taken out one by one from the mounting table 11 using the planting claws 14 and successively planted in the field.

As shown in FIGS. 4 and 5, the left and right swing cases 6, 6 are connected to the piston rod 19 of the pitching control hydraulic cylinder 18, which is fixedly installed above the transmission case 2. A swing plate 22 is connected to a fixed plate 20 via a pivot 21, and a rolling control hydraulic cylinder 23 and a piston rod 24 are interposed between these plates 20 and 22, and are integrally connected to the swing cases 6, 6. Both left and right ends of the swing plate 22 are connected to the swing arms 25, 25 through swing rods 26, 26, and the wheels 5, 5 are raised and lowered simultaneously by the expansion and contraction of the piston rod 19, so that the wheels 5, 5 move the aircraft body. While adjusting the support height, the left and right support heights of the machine body by the left and right wheels 5, 5 are varied by the expansion and contraction operation of the piston rod 24, so that the horizontal inclination of the machine body, that is, the planting section 13 is adjusted. ing.

Further, a hydraulic switching valve 27 for controlling the operation of the pitching control hydraulic cylinder 18 is provided on one side of the transmission case 3, and this switching valve 27 is connected to the pitching sensor 17. The end is supported on the rotation fulcrum shaft 28 so as to be able to swing up and down, and the switching arm 31 of the switching valve 27 is connected via a rod 30 to a swinging plate 29 that is integrally connected to the arm 17a, thereby adjusting the support height of the aircraft. Changes in the vertical inclination of the front part of the float 7 due to changes in the height of the float 7 are detected via the sensor 17 and
is configured to operate.

As shown in FIG. 6, a rotary hydraulic switching valve 32 for controlling the operation of the rolling control hydraulic cylinder 23 is fixedly installed on the base frame 33 of the engine 1, and a sensor that integrally connects the left and right rolling sensors 16, 16. The intermediate portion of the arm 34 is swingably supported by the rotating spool 35 of the switching valve 32 via a transmission shaft 36 and a bearing 37, so that the relative positional relationship with the rolling sensor 16 changes as the aircraft tilts from side to side. The switching valve 32 is operated via the rotating spool 35 when the switching valve 32 is opened.

By the way, as shown in FIG. 1, the hydraulic cylinder 23 is connected to a hydraulic pump 38 via a hydraulic switching valve 32.The switching valve 32 is of an open center type so that the spool 35 of the valve 32 is in the neutral position. When in this position, the pump port P, tank port T, and cylinder ports A and B are communicated with each other so that the piston rod 24 of the cylinder 23 can be freely expanded and contracted.

Incidentally, reference numeral 38 denotes side floats that are arranged on both left and right sides of the rear end portion of the float 7 as necessary.

The present embodiment is configured as described above, and when the height of the rice field relative to the machine body changes due to changes in the unevenness of the tiller during rice planting work, the sensors 16 and 17 are adjusted in proportion to this. The switching valves 27 and 32 are switched as appropriate, and when the ground pressure changes as the height of the planted field changes and the front part of the float 7 swings up and down, the pitting sensor 17 detects this and telescopes the hydraulic cylinder 18 via the switching valve 27 to control both wheels 5,
Adjustment of the support height by 5 is performed at the same time. On the other hand, when the rolling sensor 16 detects a change in the height of the planted field due to the left and right tilt of the machine body, the hydraulic cylinder 23 is expanded and contracted via the switching valve 32, and the height of the left and right machine body supported by both wheels 5, 5 is adjusted. are adjusted to different states to maintain the machine body, that is, the planting section 13 horizontally with respect to the planting field.

During such work, when the rolling sensor 16 is in a dead zone, that is, when the switching valve 32 is in the neutral position as shown in FIG. It is able to expand and contract freely, and even if the body, that is, the planting section 13, tilts slightly to the left or right under such conditions, the buoyancy of the float 7 and the restoring force of the link 8 will keep the body level. maintained. Therefore, regardless of whether the neutral range of the switching valve 32 is wide or narrow, stable work can always be carried out with a constant planting depth.

7 to 8 show another example of a modified structure, in which rolling sensors 16a, 16a are provided in the planting part of a riding rice transplanter, and 39 in the figure is a moving rice transplanter. 40 is an engine mounted on the base frame 41; 42 is a transmission case connected to the rear end of the base frame 41;
Reference numeral 43 denotes a swing case connected to the left and right sides of the rear end of the transmission case 42, 44 and 45 front and rear wheels for driving in rice fields, 46 a driver's seat, 47 a steering handle, and 48 three points at the rear of the aircraft body 39. A planting section for multi-row planting connected and supported via a link mechanism 49, 5
0 is a seedling stand provided in the planting section 48, 51 is a planting claw,
52 is a float, and left and right rolling sensors 16a, 16a are supported on both left and right sides of a main frame 54 that is integrally fixed to the planting case 53. The sensor 16a is a sensor arm 5 which is a spool.
An open center type 3-position 4-port hydraulic switching valve 32a, 3 is fixedly supported on the frame 54 side via 5.
A compression spring 56 is interposed between the frame 54 and the sensor 16a, and the sensor 16a is normally grounded to the rice field by the spring force of the spring 56.
The frame 54 and the sensor 16a
The switching valve 32a is configured to be operated to switch the switching valve 32a whose height has changed.

It also includes two left and right hydraulic cylinders 23a, 23a for rolling control whose operation is controlled by the switching valves 32a, 32a, respectively, and piston rods 24a, 24 of these cylinders 23a, 23a.
a to both left and right sides of the main frame 54,
It is configured so that the rolling control of the planting portion 48 is performed by the expansion and contraction operations of the piston rods 24a, 24a. And left and right hydraulic cylinders 2
3a and 23a are connected to the hydraulic pump 38 via switching valves 32a and 32a, and as in the previous embodiment, when the switching valves 32a and 32a are in the neutral position, the ports P, T, A, and B are brought into communication. Each piston rod 24a, 24a is configured to freely expand and contract. Therefore, even in the case of this configuration, the switching valve 32
a, 32a are in the neutral position, even if the planting section 48 is slightly tilted to the left or right, the left and right piston rods 24a, 24a can freely expand and contract, and due to the buoyancy of the float 52, etc., the planting section 48 can be moved. The level is maintained.

"Effect of the invention" As is clear from the above embodiments, the present invention has a double-acting hydraulic cylinder 2 for rolling control that follows the planting field and maintains the planting parts 13 and 48 horizontally.
3, 23a, an open center type hydraulic switching valve 32, 32a for controlling the operation of the cylinders 23, 23a is provided, and the switching valve 32,
When the cylinder 32a is in the neutral position, the cylinders 23, 23
Since the cylinders 23, 23a are in a free operating state, even if the planting parts 13, 48 are slightly tilted from side to side within the neutral range of the switching valves 32, 32a, the cylinders 23, 23a are free to operate. The planting portions 13 and 48 are maintained horizontally by the buoyancy of the floats 7 and 52 and the restoring force of the links 8 that support the floats 7 and 52. Regardless of whether the neutral range of 32a is wide or narrow, it is possible to perform a stable planting operation with a constant left and right planting depth at all times.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram of the main parts showing an embodiment of the present invention, Fig. 2 is an overall side view, Fig. 3 is a plan view of the same,
FIG. 4 is a partially enlarged plan view, FIG. 5 is a side view of the same, FIG. 6 is a front view of the same, and FIGS. 7 and 8 are explanatory diagrams showing other examples of modified structures. 13, 48... Planting part, 23, 23a... Hydraulic cylinder, 32, 32a... Hydraulic switching valve.

Claims (1)

[Scope of utility model registration request] In a structure equipped with double-acting hydraulic cylinders 23, 23a for rolling control to follow the planting field surface and maintain the planting parts 13, 48 horizontally, an open center hydraulic switching valve 32 controls the operation of the cylinders 23, 23a. , 32a, and the switching valve 3
When the cylinders 2 and 32a are in the neutral position, the cylinders 23,
1. A horizontal control mechanism for a rice transplanter, characterized in that the horizontal control mechanism for a rice transplanter is configured such that 23a is in a freely operating state.