JP3318194B2 - Working device lifting structure of agricultural work machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working device lifting and lowering structure of an agricultural working machine in which a working device is connected to a rear portion of a traveling machine body via a four-link mechanism driven up and down by a hydraulic cylinder so as to be able to move up and down.

[0002]

2. Description of the Related Art A typical example of the above-described lifting and lowering structure of a working device of an agricultural working machine is a raising and lowering structure of a planting device of a rice transplanter. This planting device elevating structure is disclosed in, for example,
As disclosed in Japanese Unexamined Patent Publication No. 642, a hydraulic cylinder is erected over the upper link of the four-link mechanism provided at the rear of the traveling body and the fuselage, and the hydraulic cylinder is extended and the upper link is pushed up. Thus, the planting device (working device) connected to the rear link of the quadruple link mechanism is configured to be driven up.

[0003]

In the above-described lifting structure, a compression load acts on the hydraulic cylinder when the working device is lifted, so that the hydraulic cylinder needs to have a strength that does not buckle against the compression load. In this case, large diameter cylinder cylinders and piston rods were used. Also, the upper link which receives the push-up of the hydraulic cylinder is required to have a considerably large bending strength, so that not only the hydraulic cylinder but also the components of the quadruple link mechanism itself are large and heavy.

An object of the present invention is to reduce the weight and size of a hydraulic cylinder and a four-link mechanism by rationally improving the four-link mechanism and a hydraulic cylinder that drives the four-link mechanism. Another object is to simultaneously and smoothly operate the four-link mechanism vertically.

[0005]

[Means for Solving the Problems]

 [Configuration, operation and effect of the invention according to claim 1]

(Structure) The invention according to claim 1 is a working device lifting / lowering structure of an agricultural working machine in which a working device is movably connected to a rear portion of a traveling machine body via a four-link mechanism driven up and down by a hydraulic cylinder. A hydraulic cylinder is spanned over a fulcrum connecting the upper link and the fuselage side in the quadruple link mechanism and a fulcrum connecting the lower link and the rear vertical link in the quadruple link mechanism, and the hydraulic cylinder is shortened. pulling raised operating the quadruplicate link mechanism by the operation, and adapted to lower operating a quadruplicate link mechanism by extending action of the hydraulic cylinders, low the work device to said rear vertical links
Connects freely to the ring and the rear of the four-link mechanism
Rolling locks between the left and right
The work equipment has been raised to near the upper limit via the locking mechanism.
In the state, the rolling lock mechanism is a roller of the working device.
Mechanically restrains the working operation and the working equipment is close to the upper limit.
The locking function of the rolling lock mechanism
Is configured to be canceled .

(Operation) According to the above configuration, a tensile load acts on the upper link, a compressive load acts on the lower link, a bending load acts on the rear vertical link, and a tensile load acts on the hydraulic cylinder. . Therefore, it is not necessary to consider buckling of the upper link to which only a tensile load is applied. In addition, a small diameter piston rod of a hydraulic cylinder to which only a tensile load is applied is sufficient. In addition, quadruple link mechanism rises
When it is near the rising limit, the circumference of the front and rear
Rolling action is prevented, and
The upward movement will also be inhibited.

(Effect) According to the first aspect of the present invention, only the tensile strength of the upper link to which no compressive load or bending load is applied needs to be considered, so that only a thin or thin member can be used. The hydraulic cylinder on which the hydraulic cylinder operates can be of a small diameter without having to consider the buckling strength, which is effective in reducing the weight and cost of the entire four-link mechanism including the hydraulic cylinder.

[Structure, operation and effect of the invention according to claim 2]

(Structure) According to a second aspect of the invention, in the first aspect of the invention, a pair of upper and lower links in the quadruple link mechanism are independently provided on left and right sides of the hydraulic cylinder, and are independently provided as a pair of left and right. It is characterized in that it is.

(Function) According to the above configuration, the flexibility of the quadruple link mechanism against torsion is increased as compared with the case where the left and right upper links are connected by a stay or the like to increase the strength, and the traveling body from the working device side. It becomes difficult to transmit the external force from the side or the traveling machine side to the working device side. Therefore,
Even if an unreasonable external force or impact acts on the working device, the entire four-link mechanism effectively absorbs this. Conversely, even if the traveling body is inclined due to unevenness of the traveling surface or the like, the movement is absorbed by the four-link mechanism, and it is difficult to transmit the movement to the working device at the rear of the body.

(Effect) According to the second aspect of the invention, the above-mentioned effect of the first aspect of the invention is provided, and even if an unreasonable external force or impact acts on the working device, this is absorbed by the four-link mechanism. Thus, deformation and damage at the connection fulcrum between the quadruple link mechanism and the body can be avoided. Conversely, even if the traveling body slightly shakes or tilts, it is absorbed by the four-link mechanism, and the ground posture of the working device at the rear of the body is easily stabilized.

[Structure, operation and effect of the invention according to claim 3]

(Structure) According to a third aspect of the present invention, in the second aspect, a base boss of the hydraulic cylinder is sandwiched between bosses provided at the roots of the upper links, and these bosses are provided. , A single fulcrum shaft is inserted, and the upper link and the base of the hydraulic cylinder are pivotally connected to the fuselage side.

(Operation) According to the above structure, the base end of the hydraulic cylinder is pivotally connected to the fuselage side by a common fulcrum shaft in a state where it is sandwiched and positioned by the boss of the upper link from the left and right. And the load acting on the hydraulic cylinder is concentrated on one axis.

(Effect) According to the third aspect of the present invention, the above-mentioned effect of the second aspect of the present invention is provided, and it is anticipated that the upper link and the base end of the hydraulic cylinder are pivotally connected by another shaft. A phenomenon in which bending or twisting does not needlessly act on each fulcrum can be avoided, and the four-link mechanism can be operated smoothly.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall side view of a riding rice transplanter as an example of an agricultural work machine. This rice transplanter is provided with a four-link mechanism 3 which is driven up and down by a hydraulic cylinder 2 at the rear of a traveling machine body 1 driven by four-wheel drive, and a four-row planting device ( (Working device) 4 is connected.

As shown in FIG. 2, the four-link mechanism 3
An upper link 7 whose front end is pivotally connected via a fulcrum P1 to a pair of left and right vertical frame portions 6 erected at the rear of the body frame 5 of the traveling body 1; A pair of left and right lower links 8 pivotally connected via P2, and a rear vertical link 9 pivotally connected to the rear ends of the upper link 7 and the lower link 8 via fulcrums P3 and P4. The planting device 4 is connected to and supported by a boss 10 provided at a lower portion of the rear vertical link 9 so as to be able to roll around the longitudinal axis X.

More specifically, as shown in FIG. 3, the upper link 7 is formed by arranging strip plate members in parallel in a vertical position in which the plate thickness is directed to the left and right at predetermined intervals on the left and right sides. The fulcrum shaft 11 is disposed between the vertical frame portions 6.
Are linked by Each lower link 8 is made of a square pipe material. As shown in FIG. 4, bosses 8a welded and fixed to the respective front ends are connected to fulcrum shafts 12 provided in a cantilever shape on the right and left rear portions of the body frame 5. ing. Also,
The rear vertical link 9 is formed by a sheet metal processing member having a U-shaped cross section opened rearward, and the boss 10 is fixed to the lower end thereof by welding, and is fixed through the upper end of the rear vertical link 9. The boss 9a and the boss 7a welded and fixed to the rear end of the upper link 7 are connected by a fulcrum shaft 13, and the boss 8b welded and fixed to the rear of the left and right lower links 8 and the lower part of the rear vertical link 9. And a boss 9b welded to the boss 9b.

The hydraulic cylinder 2 is of a single-acting type that is shortened by supply of pressurized oil. The front end of the cylinder cylinder 2a has a fulcrum shaft 11 at a connecting point between the upper link 7 and the vertical frame 6. They are shared and pivotally connected. That is, as shown in FIG. 4, the boss 7b is fixed to the front ends of the left and right upper links 7 so as to penetrate, and the base boss 2c of the cylinder cylinder 2a is sandwiched between the two bosses 7a. In this state, a single fulcrum shaft 11 is inserted through the left and right bosses 6a fixed to the vertical frame 6, the left and right bosses 7b of the upper link 7, and the base boss 2c of the cylinder tube 2a. -ing

At the fulcrum P4 at which the lower link 8 and the rear vertical link 9 are pivotally connected, the left and right ends of a support member 15 formed by bending a band plate material into a trapezoidal shape in plan view are connected to the fulcrum shaft 1.
4 for pivotal connection. Here, bosses 15a are provided on both left and right ends of the support member 15, and the boss 15a is connected to the boss 8b of the lower link 8 and the rear vertical link 9
Boss 9b. A piston rod 2b extending rearward from a cylinder cylinder 2a of the hydraulic cylinder 2 is slidably inserted into the center of the support member 15, and the piston rod 2b
Support washer 16 and support member 1 attached to the penetrating end of
A suspension spring 17 made of a compression coil spring is interposed between the suspension spring 17 and an intermediate portion of the fifth spring. A bush 18 made of a bearing metal or plastic is provided at the center of the support member 15 to slide the piston rod 2b with low resistance. The spring washer 1
The position 6 can be adjusted by a nut 19 mounted on the piston rod 2b, and the cushion function of the suspension spring 17 can be adjusted by this adjustment.

The lifting structure of the present invention is configured as described above. By operating a control valve (not shown) to supply hydraulic oil to the hydraulic cylinder 2 and shorten it, the four-link mechanism 3 is pulled up. The planting device 4 can be raised,
By draining the oil from the hydraulic cylinder 2 and performing the free extension operation, the quadruple link mechanism 3 can be swung down and the planting device 4 can be lowered by its own weight. Further, even in the neutral state where the shortening operation of the hydraulic cylinder 2 is stopped, the four-way link mechanism 3 is allowed to slightly move up and down within the elastic flexibility range of the suspension spring 17.

Considering the loads acting on each part of the quadruple link mechanism 3 in FIG. 8, the upper link 7 receives a tensile load, the lower link 8 receives a compressive load, and the rear vertical link 9
, And a tensile load acts on the hydraulic cylinder 2. Therefore, it is not necessary to consider the buckling of the upper link 7 to which only the tensile load is applied, and it is possible to sufficiently withstand the band plate material as described above, and the piston rod 2b of the hydraulic cylinder 2 to which only the tensile load is applied has a small diameter. Will be enough. Further, since the loads acting on the left and right ends of the support member 15 act near the end of the fulcrum shaft 14, a large bending load is not applied to the fulcrum shaft 14,
Fulcrum shaft 14 requires only the axis of the small diameter.

Between the rear end of the lower link 8 in the quadruple link mechanism 3 and the front part of the planting device 4, the rolling operation of the planting device 4 when the quadruple link mechanism 3 is raised is mechanically limited. A rolling lock mechanism 20 is provided. That is, as shown in FIGS. 6 and 7 , brackets 22 are provided on the left and right sides of a frame plate 21 provided at the front of the planting device 4, and the upper end fitting 23 a of the restraining rod 23 inserted through the bracket 22 is attached to the lower part. The rear extension 8c of the link 8 is connected to the front and rear elongated holes 24 and pins 25 via pins 25, and a pair of coil springs 26 and 27 are externally fitted to the restraining rod 23 above and below the bracket 22. The upper coil spring 26 has its upper end received and supported by a spring receiving washer 28 fixed to the restraining rod 23, and the lower coil spring 27 has its lower end received and supported by a spring receiving washer 29 whose position can be adjusted.

According to the rolling lock mechanism 20 having the above structure, the rear extension 8c of the lower link 8 swings upward about the fulcrum shaft 14 as the quadruple link mechanism 3 is raised. When the restraining rod 23 is lifted up and becomes close to the ascending limit of the quadruple link mechanism 3, as shown in FIG. 7, the left and right restraining rods 23 compress the lower coil spring 27 to close contact with the lower spring. The rolling operation of the planting device 4 around the longitudinal axis X is prevented from being restrained, and further upward movement is also prevented from being restrained. In addition, the pin 25 is displaced in the front-rear direction with the raising / lowering operation of the quadruple link mechanism 3, but this displacement is absorbed by the long hole 24 formed in the front-end bracket 23a of the restraining rod 23 in the front-rear direction. Restraint rod 23
The penetration angle with respect to the bracket 22 is substantially constant, thereby preventing the restraining rod 23 from being twisted at the portion where the four-link mechanism 3 is moved up and down at the portion where the bracket 22 is inserted.

[Brief description of the drawings]

FIG. 1 is an overall side view of a rice transplanter.

FIG. 2 is a side view of a quadruple link mechanism.

FIG. 3 is a plan view of a quadruple link mechanism.

FIG. 4 is a longitudinal rear view showing a front fulcrum of the quadruple link mechanism.

FIG. 5 is a plan view of a suspension mechanism.

FIG. 6 is a side view of a rolling lock mechanism.

FIG. 7 is a longitudinal rear view showing a rear fulcrum and a rolling lock mechanism of the quadruple link mechanism.

FIG. 8 is a schematic side view of a quadruple link mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling body 2 Hydraulic cylinder 2c Base end boss 3 Quadruple link mechanism 4 Working device 7 Upper link 8 Lower link 9 Rear vertical link 20 Rolling lock mechanism P1 Support point P4 Support point

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A01B 63/10 A01C 11/02 320

Claims (3)

(57) [Claims] 1. A work equipment lifting / lowering structure of an agricultural work machine in which a work equipment is connected to a rear part of a traveling machine body via a four-link mechanism driven up and down by a hydraulic cylinder so as to be movable up and down. A hydraulic cylinder is erected across the fulcrum connecting the link and the fuselage side and the fulcrum connecting the lower link and the rear vertical link in the four-link mechanism, and the four-link mechanism is raised and raised by the shortening operation of the hydraulic cylinder. Activating the hydraulic cylinder to lower the four-link mechanism by the extension operation of the hydraulic cylinder, and linking the working device to the rear vertical link in a freely rotatable manner.
At the same time,
Rolling lock mechanism interposed between left and right parts of industrial equipment
When the working equipment is raised to near the upper limit, the low
A ring lock mechanism mechanically controls the rolling operation of the work equipment.
Work equipment is lowered below the upper limit.
Then, the locking function of the rolling lock mechanism is released.
A lifting / lowering structure for a working device of an agricultural working machine, wherein the working device is configured as follows . 2. The lifting / lowering structure for a working device of an agricultural working machine according to claim 1, wherein the upper link in the quadruple link mechanism is provided as a pair of left and right independently positioned on the left and right sides of the hydraulic cylinder. 3. An upper link and a hydraulic cylinder, wherein a base boss of the hydraulic cylinder is sandwiched between bosses provided at the roots of the upper links, and a single fulcrum shaft is inserted through these bosses. 3. The structure of claim 2, wherein the base is pivotally connected to the machine body.