JP2530336Y2 - Dusting prevention control device for working vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to an anti-dusting control device for a working vehicle such as an agricultural tractor.

[Problems to be Solved by the Related Art and the Invention] Generally, in this type of working vehicle, when the working unit set at the upper limit position is lowered to the working height,
For example, when the working unit is a rotary cultivator, the tilling reaction force of the tilling blade acts to exert a forward force on the fuselage, thereby causing the fuselage to undergo a so-called dusting action of being strongly pushed forward. There is. Therefore, in order to avoid the above-described problem, there is a method in which dusting prevention is performed by reducing the lowering speed of the working unit to the anti-dusting speed before the working unit reaches the working height.

However, in the past, since the anti-dusting mechanism was built in the hydraulic cylinder for lifting and lowering the working unit, it was difficult to adjust the anti-dusting speed and the anti-dusting control start position, and therefore, when the working unit was replaced, Even when working using the same working unit, the work depth is shallow,
When field conditions and the like change, it is difficult to perform optimal anti-dusting control corresponding to individual work conditions, which has been a problem.

[Means for Solving the Problems] The present invention has been conceived in view of the above-described circumstances and has an object to provide a control device for preventing dusting of a work vehicle that can eliminate these disadvantages. Then, the flow rate of oil discharged from the hydraulic cylinder for lifting and lowering the working unit, which causes the lift arm to swing up and down,
In a working vehicle provided with an anti-dusting control mechanism for limiting the work unit descent speed by restricting at a stage before the work unit reaches the work height, the anti-dusting control mechanism includes:
An adjusting lever provided to be adjustable to adjust the flow rate of the discharged oil to adjust the anti-dusting speed; a poppet provided to be movable to restrict the flow rate of the discharged oil; and moving the poppet. A casing provided with an operating pin movably provided is mounted on one side in the left-right direction of the hydraulic housing, while a plate for moving the poppet interfering with the operating pin is provided on one side of the hydraulic housing. The connecting rod connecting the plate and the responsive body that responds to the swing of the lift arm is adjustable in length so that the anti-dusting control start position can be adjusted, and the hydraulic housing can be moved in the left-right direction. It is characterized by being arranged so as to correspond to one side.

According to the present invention, it is possible to easily adjust the optimum anti-dusting control in accordance with the working conditions.

Next, an embodiment of the present invention will be described with reference to the drawings.
In the drawings, 1 is a traveling body of an agricultural tractor,
A rotary tilling type working unit 2 is attached to a rear portion of the traveling machine body 1 via a lifting link mechanism 3. The working unit 2 is vertically moved up and down by a lift arm 5 that swings in conjunction with an expansion / contraction operation of a hydraulic cylinder 4 (single action type) described later. Reference numeral 6 denotes a lifting operation lever for operating the hydraulic cylinder 4.

Reference numeral 7 denotes a hydraulic housing in which the hydraulic cylinder 4 and the like are integrally assembled. A support shaft 5a of the lift arm 5 is rotatably and horizontally passed through a rear end of the hydraulic housing 7. However, an operating arm 5b is fixedly provided at an intermediate portion of the support shaft 5a. The operating arm 5b contacts the cylinder rod 4a of the hydraulic cylinder 4 and is swung by the hydraulic operation. The lifting arm 5 swings up and down, and the working unit 2 moves up and down as described above.

On the other hand, reference numeral 8 denotes a control valve housed in the hydraulic housing 7. The control valve 8 supplies oil supplied from a hydraulic pump (not shown) to the hydraulic cylinder 4 in accordance with the operation of the elevating operation lever 6. The expansion and contraction of the hydraulic cylinder 4 is controlled by switching between a raised state in which the hydraulic cylinder 4 is fed, a lowered state in which oil in the hydraulic cylinder 4 is discharged to a hydraulic tank (not shown), and a neutral state. Also,
Reference numeral 9 denotes a flow control valve interposed between the hydraulic cylinder 4 and the control valve 8. The flow control valve 9 limits the flow rate of oil discharged from the hydraulic cylinder 4 to reduce the lowering speed of the working unit 2. In this case, the lowering speed can be adjusted by changing the flow rate of the discharged oil by operating the adjusting unit 9a.

Reference numeral 10 denotes an anti-dusting device which is detachably attached to one side surface of the hydraulic housing 7 in the left-right direction. The anti-dusting device 10 is piped to be interposed between the hydraulic cylinder 4 and the flow control valve 9 in a hydraulic mechanism. ing. This is a cylindrical case body 1 that is mounted on one side in the left-right direction of the hydraulic housing 7 in a state facing up and down.
1, a plug 12 that closes the upper opening of the case body 11, a speed adjusting lever 13 whose lower end penetrates the plug 12 vertically in a threaded manner, and a pin 14 at the lower end of the speed adjusting lever 13. 15 that can be moved up and down
Actuating pin 16 that fits vertically into the lower opening 11
Are arranged in a straight line in the up-down direction.To be more specific, the case body 11 is formed with a step portion 11a having a different inner diameter at the top and bottom, and furthermore, a step portion 11a is formed. A first oil port 11b and a second oil port 11c are formed in upper and lower portions. Also,
The poppet 15 is formed in a hollow shape, and an engaging hole 15a is formed on a side surface of the poppet 15 for loosely engaging the pin 14.The bottom of the poppet 15 further projects downward by an inclined surface 15b. It is formed in a mountain shape. And this slope 15
b is opposed to the step 11a of the case body 11 with a small gap A.

On the other hand, 17 is a connecting rod, and the connecting rod 17 is
It is disposed opposite to one side in the left-right direction of the hydraulic housing 7, its rear end is pivotally attached to one end of the support shaft 5 a, and the front end is swingable on one side in the left-right direction of the hydraulic housing 7. Pivotally attached to the plate 18 which is pivotally supported, the plate 18 is displaced in the front-rear direction as the working unit 2 moves up and down, causing the plate 18 to swing. And a contact pin 18a that interferes with the contact.

Next, the operation of the anti-dusting device 10 shown in FIGS. 6A, B and C will be described. First, when the raising / lowering operating lever 6 is operated to the ascending side when the working unit 2 is at the lowering position, the oil sent through the control valve 8 flows into the anti-dusting device 10 from the second oil port 11c. But this oil is poppet
15 is pushed up to flow from the first oil port 11b to the hydraulic cylinder 4 to extend the hydraulic cylinder 4, whereby the working unit 2 is raised at a constant speed.

On the other hand, when the raising / lowering operation lever 6 is moved to the lower side while the working unit 2 is at the upper position, the control valve 8 is switched to discharge the oil in the hydraulic cylinder 4 and the first oil port 11
Oil flows into the anti-dashing device 10 from b. At this time, since the contact pin 18a of the plate 18 pushes the operating pin 16 up, the poppet 15 is also pushed up, so that the gap A is widened. Nine or more oil discharges are allowed. In this state, the working unit 2 descends at a normal speed that is not decelerated. However, as the working unit 2 continues to descend, the operating pin 16 and the poppet 15 are displaced as the connecting rod 17 is gradually displaced forward.
Moves down. And when the poppet 15 reaches the lower limit position,
The upward movement of the poppet 15 is regulated by the pressure of the oil flowing into the hollow portion, and only the discharge of oil from the preset gap A is allowed (less than the allowable discharge amount of the flow control valve 9). Thus, the lowering speed of the hydraulic cylinder 4 becomes slower, and the lowering speed of the working unit 2 is reduced to the anti-dusting speed.

Further, according to this embodiment, the anti-dusting speed and the anti-dusting control start position can be freely set and adjusted by adjusting the length adjusting turnbuckle 17a provided at an intermediate portion between the speed adjusting lever 13 and the connecting rod 17. You can do it. That is, when the speed adjusting lever 13 is turned, the speed adjusting lever 13 moves up and down under the guidance of the plug 12 to which the screw is screwed, whereby the poppet 15 moves up and down to change the gap A, thereby lowering the working unit. The discharge flow rate during operation changes to adjust the anti-dusting speed. Further, the timing at which the poppet 15 reaches the lower limit position can be set and adjusted by adjusting the length of the connecting rod 17 by the turnbuckle 17a to set the anti-dusting control start position.

In the embodiment of the present invention configured as described above, the anti-dashing device 10 and the connecting rod 17 can be easily assembled only by performing a simple process of drilling a screw hole in the hydraulic housing 7. After being assembled, the anti-dusting speed can be adjusted by operating the speed adjusting lever 13, and the anti-dusting control start position can be freely set and adjusted by changing the rod length by the turnbuckle 17a.

As described above, when the working unit 2 descends, the descending speed is reduced to the anti-dusting speed at the stage before reaching the working height when the working unit 2 descends, and the working unit 2 receives the dusting action. The anti-dashing mechanism is not provided in the hydraulic cylinder as in the prior art, but is mounted on one side in the left-right direction of the hydraulic housing 7 and connected to the connecting rod 17 to swing the lift arm 5. Since the operation is performed based on the movement, the setting and adjustment of the anti-dusting speed and the anti-dusting control start position can be easily performed by operating the speed adjusting lever 13 provided in the anti-dusting device 10 and changing the rod length by the turn buckle 17a. be able to. Therefore, replacing the working unit 2,
Further, in the work using the same work unit 2, when the work depth is shallow, field conditions, and the like are changed, it is possible to finely adjust the anti-dusting speed and the anti-dusting control start position in accordance with the work conditions. By being able to concentrate on one side of the hydraulic housing 7 in the left-right direction, it is easy to adjust to the optimal anti-dusting control corresponding to each work condition, and highly accurate work can be performed efficiently.

In addition, in this case, the anti-dashing device 10 and the connecting rod 17 can be easily assembled simply by forming a screw hole on one side in the left-right direction of the hydraulic housing 7 so that the size can be reduced. It can contribute to simplification of the structure.

[Effects] In summary, since the present invention is configured as described above, when the working unit descends, the descending speed is reduced to the anti-dusting speed at a stage before reaching the working height, and the dusting effect is obtained. The anti-dashing control mechanism is designed such that the casing provided with the adjusting lever, the poppet, and the operating pin is mounted not on the hydraulic cylinder but on one side in the left-right direction of the hydraulic housing. A plate that interferes with the pin, and a connecting rod whose length can be adjusted to connect the plate and a responding body that responds to the swing of the lift arm, are arranged on one side in the left-right direction of the hydraulic housing. The members can be compactly arranged on one side in the left-right direction of the hydraulic cylinder, so that the structure can be simplified.

In addition, the adjustment of the anti-dusting speed and the adjustment of the start position of the anti-dusting control can be performed on one side in the left and right direction of the same hydraulic housing. As a result, the working part is replaced or the working depth is reduced in the work using the same working part. The work of adjusting the anti-dusting speed and the anti-dusting control start position, which is performed in the case where the depth is shallow, changes in field conditions, or the like, can be concentrated on one side in the left and right direction of the hydraulic housing, thereby improving workability. In addition, highly accurate adjustment work can be performed efficiently.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an anti-dusting control device for a working vehicle according to the present invention. FIG. 1 is an overall side view of an agricultural tractor, FIG. 2 is a side view of a hydraulic housing, FIG. FIG. 3 is a plan view of the same, FIG. 4 is a schematic explanatory view showing a main part of the hydraulic mechanism, FIG. 5 is a longitudinal sectional view of the anti-dusting device, and FIGS. It is an operation explanatory view showing the state of each part at the time of operation (normal speed) and at the time of descent operation (dusting prevention speed). In the figure, 1 is a traveling body, 2 is a working unit, 4 is a hydraulic cylinder,
5 is a lift arm, 7 is a hydraulic housing, 10 is an anti-dusting device, 11 is a case body, 13 is an adjusting lever, 15 is a poppet, 16 is an operating pin, 17 is a connecting rod, and 18 is a plate.

Claims (1)

(57) [Scope of request for utility model registration] The working unit descends by restricting the flow rate of oil discharged from the working unit elevating hydraulic cylinder, which causes the lift arm to swing up and down, when the working unit is lowered at a stage before the working unit reaches the working height. In a working vehicle provided with an anti-dusting control mechanism for reducing the speed, the anti-dusting control mechanism is provided with an adjusting lever that is adjustably provided to adjust the flow rate of the discharged oil to adjust the anti-dusting speed. ,
A casing provided with a poppet movably provided to limit the flow rate of the discharged oil and an operating pin movably provided to move the poppet, which is assembled to one side in the left-right direction of the hydraulic housing. On the other hand, a connecting rod is provided on one side of the hydraulic housing so as to be capable of swinging a poppet for interfering with the operating pin and for moving the poppet, and connecting the plate with a responsive body responsive to the swing of the lift arm. Wherein the length is freely adjustable so that the start position of the anti-dusting control can be adjusted, and is disposed so as to face one side in the left-right direction of the hydraulic housing.