JPH064656Y2 - Cushion device for lowering rotary part of agricultural tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application This invention relates to a cushioning device for lowering a rotary portion of an agricultural tractor.

(B) Conventional Technology Conventionally, the descending speed of the rotary portion connected to the agricultural tractor has been adjusted by finely adjusting the slow return valve provided between the hydraulic actuator and the hydraulic control valve.

(C) Problems to be solved by the invention However, the descent speed adjustment by the slow return valve is
Since the lowering operation is performed over the whole time, it takes time for the rotary part to reach the tilling position, which reduces work efficiency.Therefore, leave the valve wide open and let the operator adjust the lever operation near the end of the descending crop. It is widely practiced to slow down the descending speed, but it is difficult to operate and it is easy to make a mistake.If the rotary part suddenly touches the ground and the plowing pawl is suddenly pulled into the ground, the load on the prime mover will be reduced. However, there was a drawback that the governor could not follow it and caused an engine stall, damage to various parts, and worsen the tillage finish.

(D) Means for Solving the Problem In the present invention, in the rotary part elevating mechanism configured to elevate and lower the rotary part by rotating the hydraulically operated lift arm, the base end part of the lift arm is tapered. The pin is attached so that it can be screwed, and the raising operation lever and the cam plate are connected to the control shaft of the hydraulic control valve for controlling the operation of the lift arm, and the raising operation lever and the cam plate are interlocked. It is possible to change the contact position of the tapered pin with respect to the cam plate, and the tapered pin contacts the cam plate in the vicinity of the end of the lowering operation of the lift arm to operate the control shaft. To provide a rotary part lowering operation cushion device for an agricultural tractor configured to reduce the opening degree of the hydraulic control valve to reduce the lowering speed of the rotary part. It

(E) Action In this invention, a tapered pin is screwed to the base end of the lift arm, and the tapered pin can be screw-adjusted to change the contact position with the cam plate. In the vicinity of the end of the rotary part lowering operation, the opening of the hydraulic control valve is reduced by the contact between the pin and the cam plate, and the throttling effect slows down the rotary part lowering speed only near the end to gently touch the rotary part. It is what makes me.

Further, the operation range of the cam plate can be changed by operating the raising operation lever.

(F) Effect According to this invention, the rotary unit is shortened in the tilling position to improve work efficiency while preventing the engine stall and damage to each component when the rotary unit is in contact with the ground and improving the tillage finish. There is an effect.

Further, since the raising operation lever and the cam plate are connected to the control shaft of the hydraulic control valve so that the raising operation lever and the cam plate can be interlocked, the operation range of the cam plate can be changed by operating the raising operation lever. Therefore, it is possible to make fine adjustments according to the degree of tillage and the soil conditions in the field.

Moreover, since the tapered pin provided on the lift arm can be screw-adjusted to change the contact position with respect to the cam plate, fine adjustment of the position for reducing the descending speed of the rotary portion according to the field conditions can be performed. It can be optimized.

(G) Example To explain the example of the present invention in detail with reference to the drawings, (A) shows an agricultural tractor, in which the power of a prime mover part (1) arranged in the front part is applied to the rear part of the prime mover part (1). It is transmitted to the transmission case (3) that is connected to the rear of the clutch housing (2) through the clutch housing (2) that is connected to the left and right rear wheels (4 ) Drive the same case
A four-wheel drive agricultural tractor (A) is driven by driving the left and right front wheels (6) arranged below the left and right sides of the prime mover (1) through a propeller shaft (5) extending forward from (3). ) Is composed.

At the rear of the tractor (A), a rotary portion (10) is vertically movable via a three-point link type coupling mechanism (9) consisting of a top ring (7) and left and right lower links (8). .

A hydraulic cylinder (11) for raising and lowering the rotary portion (10) is arranged on the upper surface of the mission case (3), and the expansion and contraction operation of the cylinder (11) is linked with the cylinder (11). It is transmitted to the lift arm (12) to vertically move the rear end of the arm (12), and the lift rod (13) is provided between the rear end and the middle part of the left and right lower links (8). The rotary portion (10) is configured to move up and down by expanding and contracting the cylinder (11).

A hydraulic control valve (14) is provided to control the expansion / contraction operation of the hydraulic cylinder (11), and the control shaft (1) of the hydraulic control valve (14) is
5) projects outward from the right side surface of the hydraulic cylinder (11) and is configured to rotate the control shaft (15) to move the hydraulic cylinder (11) back and forth. ), The base end of the raising operation lever (16) erected on the right side of the driver's seat is loosely fitted, and the forward and backward rotation operation of the lever (16) is performed via the disc spring-shaped friction plate (17). It is configured to transmit to the control shaft (15).

On the other hand, on the front upper surface of the mission case (3), the main transmission lever
(18) is erected, and the right end of the shift shaft (19) of the main transmission (3 '), which is interlocked with the base end (18-1) of the main transmission lever (18) on the left side, is connected to the case (3). ) Projection (19-1) to the outside from the right side
When the main transmission lever (18) is operated to the reverse position (R) by connecting the claw clutch (20) to the protruding portion (19-1) in series, engage the clutch (20), The operating lever (2) provided between the clutch (20) and the control shaft (15) of the hydraulic control valve (14).
1), through the interlocking mechanism (M) consisting of the interlocking rod (22) and the passive lever (23), the operation operation to the reverse position of the main speed change lever (18) is transmitted to the control shaft (15), (15) is rotated to extend the hydraulic cylinder (11) to raise the rotary part (10).

When the main transmission lever (18) is moved to a position other than reverse, the interlocking mechanism (M) operates in the opposite direction to the above, but the pawl clutch (20) is disengaged and the rear end of the interlocking rod (22). The control shaft (15) holds the rotary portion (10) at a high position by holding the lifted position of the control shaft (15) by the long hole (22-1) and the friction plate (17) provided in the rotary portion (10). In order to lower it, the lowering lever (29) is operated to the lowering position.

On the rear side of the boss (23-1) of the passive lever (23), the cam plate (24)
Is extended in the rear direction, and the cam plate (24) has the rear end (24-1).
Is bent upward, and a substantially triangular projecting portion (25) is formed in the upward direction at the inner curved edge of the cam plate (24) on the upper surface of the middle portion thereof.

On the other hand, on the right end side surface of the base end part (12-1) of the lift arm (12),
The pin support plate (26) is hung vertically downward.
At the lower end of 6), a tapered pin (27) having a gradually increasing diameter is screwed from the right side so as to be screw-adjustable in the axial direction of the pin (27).

Then, when the rotary portion (10) is operated downward, that is, when the lift arm (12) is rotated downward and reaches the vicinity of its end,
The pin (27) slides forward while contacting the upper edge of the rear end (24-1) of the cam plate, rides on the substantially triangular projecting portion (25), and pushes down the cam plate (24). Control Axis (15) for Hydraulic Control Valve (14)
Is rotated to decrease the opening of the hydraulic control valve (14), and the throttle effect reduces the descending speed near the end of the descending operation of the rotary part (10), so that the rotary part (10) is gently moved. It is a landing.

Therefore, the increase in power consumption of the rotary part (10) becomes gradual, the governor follows this increase to prevent stalling, and also to prevent damage to each part due to impact load,
This is to improve the tillage finish.

The start timing of the deceleration operation and the degree of deceleration can be adjusted by adjusting the screwing of the tapered pin (27) to the pin support plate (26).

A contact plate (16-1) is connected to the raising operation lever (16), and the raising operation lever (16) is operated by contact between the contact plate (16-1) and the passive lever (23). The rotary part (10) can be moved up by the lever (16).

In the figure, (28) shows a stopper bolt for limiting the downward movement of the cam plate, and (30) shows an auxiliary lever.

[Brief description of drawings]

FIG. 1 is a side view showing a main part of the structure of the present invention. FIG. 2 is a plan view of the same. FIG. 3 is a shift pattern diagram of the main shift lever. FIG. 4 is an overall side view of an agricultural tractor having the structure of the present invention. (10): Rotary part (12): Lift arm (12-1): Base end part (14): Hydraulic control valve (15): Control shaft (16): Raising lever (24): Cam plate (27) : Tapered pin

Claims (1)

[Scope of utility model registration request] 1. A rotary end lifting mechanism configured to lift and lower a rotary part (10) by rotating a hydraulically operated lift arm (12), and a base end part (12-1) of the lift arm (12). ), A taper-shaped pin (27) is attached so that the screw can be adjusted, and a lift control lever (16) is attached to the control shaft (15) of the hydraulic control valve (14) for controlling the operation of the lift arm (12). )
And the cam plate (24) are connected in series so that the raising operation lever (16) and the cam plate (24) can be interlocked, and the tapered pin (2
The contact position of 7) with respect to the cam plate (24) can be freely changed, and moreover, in the vicinity of the end of the lowering operation of the lift arm (12),
The tapered pin (27) abuts on the cam plate (24) so that the control shaft
A rotary part lowering operation cushion device for an agricultural tractor configured to operate (15) and reduce the opening degree of the hydraulic control valve (14) to reduce the lowering speed of the rotary part (10).