JPH09294408A - Structure for lifting and lowering working device of farm working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out lightening and cost reduction of a quadruple link mechanism containing a hydraulic cylinder in a working device lifting and lowering structure of a farm working machine and make operation of the quadruple link mechanism smooth. SOLUTION: A hydraulic cylinder 2 is installed over a support P1 connecting an upper link 7 to a machine body side in a quadruple link mechanism 3 and a support P4 connecting a lower link 8 to a rear vertical link 9 in the quadruple link mechanism 3, and the quadruple link mechanism 3 is pulled up and raised by shortening operation of the hydraulic cylinder 2 and the quadruple link mechanism 3 is lowered by stretching operation of the hydraulic cylinder 2 and the upper links 7 are situated on right and left both sides of the hydraulic cylinder 2, and a pair of right and left upper links 7 are independently provided and base end boss 2c of the hydraulic cylinder 2 is nipped between bosses provided in the root part of both upper links 7 and a single support shaft 11 is inserted over these bosses, and the upper link 7 and the base of the hydraulic cylinder 2 are pivoted and connected to the machine side.

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, Japanese Patent Laid-Open No. 8-70.
As disclosed in Japanese Laid-Open Patent Publication No. 642, a hydraulic cylinder is installed over the upper link of a four-link mechanism provided at the rear part of the traveling machine body and the machine body, and the hydraulic cylinder is extended to push up the upper link. Thus, the planting device (working device) connected to the rear link of the four-link mechanism is configured to be driven upward.

[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.

The main object of the present invention is to reduce the weight and size of the hydraulic cylinder and the four-link mechanism by rationally improving the four-link mechanism and the hydraulic cylinder for driving the four-link mechanism. At the same time, another purpose is to smoothly and vertically move the four-link mechanism.

[0005]

[Means for Solving the Problems]

 [Structure, Action and Effect of Invention According to Claim 1]

(Structure) The invention according to claim 1 is a working device lifting structure for an agricultural working machine in which a working device is movably connected to a rear portion of a traveling machine body through a four-link mechanism which is driven to move up and down by a hydraulic cylinder. A hydraulic cylinder is installed over a fulcrum that connects the upper link and the fuselage side in the four-link mechanism and a fulcrum that connects the lower link and the rear vertical link in the four-link mechanism and shortens the hydraulic cylinder. It is characterized in that the quadruple link mechanism is pulled up and raised by the operation, and the quadruple link mechanism is lowered by the extension operation of the hydraulic cylinder.

(Operation) According to the above construction, a tensile load is applied to the upper link, a compressive load is applied to the lower link, a bending load is applied to the rear vertical link, and a tensile load is applied to 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.

(Effect) According to the invention of claim 1,
The upper link, which is not subject to compressive or bending loads, needs only to consider the tensile strength, so a thin or thin member is sufficient, and a hydraulic cylinder that only tensile load acts on does not need to consider buckling strength. This is effective for weight reduction and cost reduction of the entire 4-link mechanism including the hydraulic cylinder.

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

(Structure) In the invention according to claim 2, in the invention according to claim 1, a pair of upper and lower links of the quadruple link mechanism are independently provided on both left and right sides of the hydraulic cylinder. It is characterized by being

(Operation) According to the above construction, the four link mechanism has a greater flexibility in torsion as compared with the case where the left and right upper links are connected by stays or the like to increase the strength, and the traveling machine body from the working device side is increased. Side, or the external force from the traveling machine side to the working device side becomes difficult to be transmitted. Therefore,
Even if an external force or impact is applied to the work device, the entire four-link mechanism effectively absorbs this. On the contrary, even if the traveling machine body is inclined due to the unevenness of the traveling surface or the like, the movement is absorbed by the four-link mechanism and is difficult to be transmitted to the working device at the rear part of the machine body.

(Effect) According to the invention of claim 2,
In addition to providing the above effect of the invention described in claim 1,
Even if an undesired external force or impact is applied to the work device, this is absorbed by the quadruple link mechanism, and it is possible to avoid deformation or damage at the fulcrum of connection between the quadruple link mechanism and the machine body or the like. On the contrary, even if the traveling machine body is slightly shaken or tilted, it is absorbed by the quadruple link mechanism, and the ground posture of the work device at the rear of the machine body is easily stabilized.

[Structure, Action and Effect of the Invention According to Claim 3]

(Structure) In the invention according to claim 3, in the invention according to claim 2, the base end boss of the hydraulic cylinder is sandwiched between the bosses provided at the root portions of the both upper links, and these bosses are sandwiched. The upper link and the base of the hydraulic cylinder are pivotally connected to the fuselage side by inserting a single fulcrum shaft over.

(Operation) According to the above configuration, the base end of the hydraulic cylinder is pinched and positioned from the left and right by the bosses of the upper links, and is pivotally connected to the body side by the common fulcrum shaft. And the load acting on the hydraulic cylinder is concentrated on one axis.

(Effect) According to the invention of claim 3,
In addition to providing the effect of the invention described in claim 2,
It is possible to avoid the phenomenon that the bending and twisting that would be expected when the upper link and the base end of the hydraulic cylinder are pivotally connected by another axis would unnecessarily act on each fulcrum, and the four-link mechanism operates smoothly. Can be made.

[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. In this rice transplanter, a four-link mechanism 3 driven and moved up and down by a hydraulic cylinder 2 is provided at the rear part of a traveling body 1 that travels 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 is used.
Is an upper link 7 whose front end is pivotally connected through a fulcrum P1 to a pair of left and right vertical frame parts 6 standing on the rear part of the machine body frame 5 of the traveling machine body 1, and front and left fulcrum points of the left and right body frames 5 It consists of a pair of left and right lower links 8 pivotally connected to each other via P2, and a rear longitudinal 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 rotatably connected to and supported by a boss portion 10 provided at the lower portion of the rear vertical link 9 such that the planting device 4 can be rolled 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 posture in which the plate thickness is directed to the left and right at a constant left and right intervals. The fulcrum shaft 11 is arranged between the vertical frame portions 6.
Are linked by Further, each lower link 8 is made of a square pipe material, and as shown in FIG. 4, bosses 8a welded and fixed to respective front end portions are connected to a fulcrum shaft 12 which is cantilevered on the left and right rear portions of the body frame 5. ing. Also,
The rear vertical link 9 is composed of a sheet metal working member having a U-shaped lateral cross-section that opens rearward, and the boss portion 10 is welded and fixed to the lower end of the rear vertical link 9 and fixed to the upper end of the rear vertical link 9 by penetration. The boss 9a and the boss 7a welded and fixed to the rear end of the upper link 7 are connected by the fulcrum shaft 13, and the boss 8b welded and fixed to the rear of the left and right lower links 8 and the lower portion of the rear vertical link 9 are connected. The boss 9b, which is welded and fixed to, is connected by a fulcrum shaft 14.

The hydraulic cylinder 2 is of a single-acting type which is shortened by the supply of pressure oil, and the front end of the cylinder 2a has a fulcrum shaft 11 at the connecting point between the upper link 7 and the vertical frame 6. Shared and pivotally connected. That is, as shown in FIG. 4, the bosses 7b are fixed by penetrating the front ends of the left and right upper links 7, and the base end boss 2c of the cylinder tube 2a is sandwiched between the bosses 7a so that the bosses 7c can be moved in the left-right direction. The positioning is performed, and in this state, the single fulcrum shaft 11 is inserted across 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 end boss 2c of the cylinder tube 2a. -ing

At the fulcrum P4 which pivotally connects the lower link 8 and the rear vertical link 9, the left and right ends of a support member 15 formed by bending the strip material into a trapezoidal shape in plan view are 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
It is sandwiched and positioned by the 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 elevating structure of the present invention is constructed as described above, and the control valve (not shown) is operated to supply the pressure oil to the hydraulic cylinder 2 to perform the shortening operation, thereby pulling up the four-link mechanism 3. 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 load acting on each part of the four-link mechanism 3 in FIG. 8, a tensile load is applied to the upper link 7, a compressive load is applied to the lower link 8, and a rear vertical link 9 is used.
Is applied to the hydraulic cylinder 2, and a tensile load is applied to 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. In addition, since the loads acting on both the left and right ends of the support member 15 act near the ends of the fulcrum shaft 14, a large bending load is not applied to the fulcrum shaft 14,
The fulcrum shaft 14 can have a small diameter.

Between the rear end of the lower link 8 of 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 lifted is mechanically restricted. A rolling lock mechanism 20 is provided. That is, as shown in FIG. 4 and FIG. 5, brackets 22 are provided on the left and right of a frame plate 21 provided in the front part of the planting device 4, and the upper end fittings 23 a of the restraint rods 23 inserted through the brackets 22 are attached to the lower part. The rear extension 8c of the link 8 is connected to the front and rear long holes 24 and the pins 25 via pins 25, and a pair of coil springs 26 and 27 are externally fitted to the check 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 elevating / lowering mechanism 20 having the above-described structure, the rear extension 8c of the lower link 8 swings upward about the fulcrum shaft 14 as the four-link mechanism 3 is lifted. When the check rod 23 is pulled up and is near the rising limit of the quadruple link mechanism 3, the check rods 23 on the left and right compress the lower coil springs 27 as shown in FIG. The rolling operation around the front-rear axis X of the planting device 4 is restrained, and further upward movement is restrained. The pin 25 is displaced in the front-rear direction in accordance with the raising / lowering operation of the quadruple link mechanism 3, and this displacement is caused by the front-rear slot 2 formed in the upper end fitting 23a of the restraining rod 23.
4, the penetration angle of the restraining rod 23 with respect to the bracket 22 becomes substantially constant, and as a result, the restraining rod 23
Is prevented from being twisted at the insertion portion of the bracket 22.

[Brief description of drawings]

[Figure 1] Overall side view of 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 portion.

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 four-link mechanism.

[Explanation of symbols]

 1 traveling machine 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 P1 fulcrum P4 fulcrum

Claims (3)

[Claims] 1. A working device elevating structure for an agricultural work 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, and an upper part of the four-link mechanism is provided. A hydraulic cylinder is installed over the fulcrum that connects the link and the fuselage side and the fulcrum that connects the lower link and the rear vertical link in the quadruple link mechanism, and the quadruple link mechanism is pulled up by the shortening operation of the hydraulic cylinder. A work device lifting structure for an agricultural work machine configured to be operated and to lower the four-link mechanism by extending the hydraulic cylinder. 2. The working device lifting structure for an agricultural work machine according to claim 1, wherein the upper links of the four-link mechanism are independently provided on the left and right sides of the hydraulic cylinder in pairs. 3. The base link boss of the hydraulic cylinder is sandwiched between the bosses provided at the roots of the both upper links, and a single fulcrum shaft is inserted across these bosses to form the upper link and the hydraulic cylinder. The working device lifting structure for an agricultural working machine according to claim 2, wherein the base portion of the above is pivotally connected to the body side.