JP3318195B2 - 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. In addition, it is common that a suspension spring is interposed between the hydraulic cylinder and the upper link so that the planting device is allowed to slightly move up and down even when the expansion and contraction of the hydraulic cylinder is stopped. is there.

[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.

Further, in the above configuration, when an impact external force acts on the working device, the impact force first acts on the suspension spring via the quadruple link mechanism, so that the suspension spring has a cushioning function. There is a possibility that a part of the link member may be deformed by an external force before exerting the force, and in order to avoid this, it is necessary to further increase the rigidity of the quadruple link mechanism.

The present invention is intended to reduce the weight of the hydraulic cylinder and the four-link mechanism by rationally improving the four-link mechanism and the hydraulic cylinder that drives the four-link mechanism. The main purpose is to improve the performance.

[0006]

[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 vertically 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 rear vertical link and a pair of left and right lower links in the quadruple link mechanism. The quadruple link mechanism is lifted and raised by the shortening operation of the cylinder, and the quadruple link mechanism is lowered by the elongating operation of the hydraulic cylinder, and a supporting member is provided on the fulcrum side connecting the rear vertical link and the lower link. Concatenate
And a suspension spring is provided between the support member and the hydraulic cylinder, and a rear suspension at the lower link is provided.
Boss, lower boss at rear vertical link, and suspension
At the left and right rear ends of the support member for receiving the pension spring
It is characterized in that the provided boss is pivotally connected by a single fulcrum shaft .

(Action) 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. The suspension spring, so are to instrumentation Bei between the fulcrum and the hydraulic cylinder for connecting the rear vertical link and a lower link that the working device is connected to and supported, when an impact to the external force is exerted on the working device, An external force acts on the suspension spring without bending the link component. In addition, the hydraulic cylinder load
Connects the rear vertical link and the lower link via the support member
Act on the supporting fulcrum
When the load of the Linda is concentrated on the middle of the fulcrum shaft
Large bending load acts on the fulcrum shaft
Can be avoided. Also, the rear vertical link and the lower
The fulcrum connecting the link and the fulcrum of the support member are configured separately.
Then, it is predicted that bending or torsion will occur between the fulcrums.
However, if a single fulcrum shaft is pivotally connected,
And twisting can be avoided.

(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. In addition, the suspension spring that acts on the fulcrum effectively exerts a cushioning function to prevent deformation and breakage of the quadruple link mechanism. I was able to make it high. In addition, bend or pry at the fulcrum
To ensure that the four-link mechanism is always smooth
Can be activated.

[0010]

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.

[0011] As shown in FIG .
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.

[0012] Specifically, as shown in FIG. 3, the upper link 7 is for the strip plate material sheet thickness are formed in parallel with the left and right fixed intervals in vertical position toward the right and left, left and right 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 a single-acting hydraulic cylinder that operates in a shortened manner by the supply of pressurized oil. The front end of the cylinder cylinder 2a has a fulcrum shaft 11 at the 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

Further, at a 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 elevating structure of the present invention is constructed as described above, by shortening operated by supplying pressurized oil to the hydraulic cylinder 2 by operating the control valve (not shown), raising the quadruplicate 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.

[0016] Here, considering the load acting on each part of quadruplicate link mechanism 3 in FIG. 8, a tensile load in the upper link 7, the compressive load on the lower link 8, 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,
The fulcrum shaft 14 can be a small diameter shaft.

Between the rear end of the lower link 8 in the four-link mechanism 3 and the front part of the planting device 4, the rolling operation of the planting device 4 when the four-link mechanism 3 is raised is mechanically limited. A rolling lock mechanism 20 is provided. That is, as shown in FIGS. 4 and 5, 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.

[0018] According to the elevation regulating mechanism 20 having the above structure, so that the quadruplicate link mechanism 3 As the is raised, rear extension part 8c of the lower link 8 swings upward about the pivot axis 14 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 close to close contact, and as a result, The rolling operation of the planting device 4 around the longitudinal axis X is prevented from being restrained, and further ascending operation is also prevented from being 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 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]

 Reference Signs List 1 traveling machine body 2 hydraulic cylinder 2c base end boss 3 quadruple link mechanism 4 working device 7 upper link 8 lower link 8b boss 9 rear vertical link 9b boss 15 support member 15a boss 17 suspension spring P1 fulcrum P4 fulcrum

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

Claims (1)

(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 bridged between a fulcrum connecting the link and the body side and a fulcrum connecting the rear vertical link and the pair of left and right lower links in the four-link mechanism, and the four-link mechanism is shortened by the hydraulic cylinder. To raise and lower the four-link mechanism by the extension operation of the hydraulic cylinder, and to support the fulcrum connecting the rear vertical link and the lower link.
A suspension spring between the support member and the hydraulic cylinder; and a rear boss in the lower link and a rear vertical rib.
Lower boss and suspension spring catch
Bosses provided on the left and right rear ends of the support member
The work equipment lifting and lowering structure of the agricultural work machine that is pivotally connected at the fulcrum shaft .