JP3340770B2 - Work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lift arm for lifting and lowering a working device, and a position lever located in front of the lift arm for lifting and lowering the working device, above a transmission case at the rear of the machine. Along with
An operation arm interlocked with the lift arm and a hydraulic cylinder that drives and swings the lift arm via the operation arm are housed in the transmission case, and a hydraulic control valve for position control with respect to this hydraulic cylinder is housed near the transmission case. Work vehicle .

[0002]

2. Description of the Related Art As the work vehicle, for example, JP-A-63-
As shown in JP-A-263001, a hydraulic cylinder for driving and swinging a lift arm for a working device elevating operation is provided on an upper portion of a transmission case at a rear portion of a fuselage.
A hydraulic control valve for controlling the position of the hydraulic cylinder is provided in the vicinity of the hydraulic cylinder, and a rotary arm connected to a position lever, a rotary arm operatively connected to a lift arm via a feedback link, and hydraulic control of these rotary arms There has been proposed a structure in which a control valve operation unit such as a balance rocking link that is interlockingly connected to a valve is disposed at a position on one side of the fuselage. Further, for example, Japanese Patent Application Laid-Open No. 60-160803
As shown in the publication, the hydraulic cylinder and the hydraulic cylinder
The operation arm that is pivotally connected to the
And deploy the hydraulic control valve to this hydraulic cylinder and
And inside the mission case below the operating arm
Deployed structures are known.

[0003]

SUMMARY OF THE INVENTION The former of the above conventional construction
In a work vehicle , an operation system such as a position lever and a feedback system such as a feedback link can be collectively arranged on one side of the machine body, which has an advantage that it is advantageous in performing assembly and adjustment. However, since the control valve operating portion was provided so as to protrude largely in front of the cylinder head in which the hydraulic control valve was incorporated, the longitudinal length from the lift arm fulcrum portion to the control valve operating portion became large, The structure was not suitable for a small model with a short front and rear length of the transmission case. And the latter of the above conventional configuration
In the work vehicle, the hydraulic control valve is
By installing inside, transmission of hydraulic oil drainage is performed as it is
The advantage of being able to discharge and return to the case and simplifying the hydraulic piping
Oscillating by a hydraulic cylinder
Operating arm interferes with the hydraulic control valve located below
Hydraulic cylinder and operating arm
Had to be deployed in Then, turn off the hydraulic control valve.
Deployed at a high position that does not interfere with the gear mechanism in the case
The hydraulic cylinder and the operating arm
In the mission case and serial
There is a drawback that the case is enlarged in the vertical direction.

The present invention has been made in view of such a point, and has as its object to reduce the size of a hydraulic operating mechanism.

[0005]

[Means for Solving the Problems]

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

[0006] (Configuration) work vehicle of the invention according to claim 1, the aft body
At the top of the transmission case, there is a
With a hydraulic cylinder that drives and swings the arm
The hydraulic control valve for this hydraulic cylinder is
In the working vehicle provided, the hydraulic cylinder is pivotally connected.
An operating arm connected to drive the lift arm;
Input bevel for differential mechanism located below operating arm
And a gear, with respect to the hydraulic control valve, of the operating arm.
The swing range and the input bevel gear correspond to the hydraulic control valve.
And place them side by side so that they overlap in side view
The operating arm, the input bevel gear, and the
When each hydraulic control valve is located in the mission case
In addition, the axis of the upper rotation drive shaft of the operation arm is
The power bevel gear is provided at a position rearward of the rotation axis of the
The cylinder, the operation arm, and the input bevel gear
While eccentrically arranged on one side from the left and right center of the body,
The hydraulic control valve is disposed at a position opposite to the hydraulic control valve .

(Operation) According to the above configuration, the side-by-side state
The operating arm and the hydraulic control valve
And does not interfere with the
It is arranged in a state of being superimposed in side view. Operation arm
Side-by-side with input bevel gears located below
The hydraulic control valves located in
Because it is arranged in the state, the operation arm, input bevel gear,
Set the hydraulic control valve not only in the vertical
It can be arranged in a reduced size. In addition, input bebe
In the positional relationship between the gear and the operating arm,
Adjust the position of the axis of the upper rotation axis of the arm to the rotation of the input bevel gear.
Since it is deviated backward from the axis of motion,
When the axial center position is located just above the rotation axis.
In comparison, the swing range of the operation arm interferes with the input bevel gear
It can be provided at a lower position within a range not to be. further,
Hydraulic cylinder, operation arm, input bevel gear on one side
On the other side, the hydraulic control valve is placed on the opposite side by the amount of eccentricity.
A large pace is secured, left and right with respect to the center of the aircraft
These devices can be arranged without bias.

(Effect) Therefore, according to the invention of claim 1, the operation arm
System, input bevel gear, and hydraulic control valve in the transmission case
With the operation arm and input bevel gear
And the hydraulic control valves are arranged side by side, and the operation arm
And the hydraulic control valve, and the input bevel gear and the hydraulic control valve.
Since they are arranged so that they overlap when viewed from the side,
Not only in the up-down direction but also in the front-back direction
The size can be reduced. In addition to this,
Input the position of the upper rotation drive shaft to the rotation axis of the input bevel gear
Input the operation arm by deviating more backward
Lower the operation arm position without interfering with the bevel gear
Can be installed in the transmission case.
The driver's seat is located above and
Also make the ground clearance relatively small for stability and livability.
This is effective in configuring an excellent driving unit. In addition,
Only the case can be downsized vertically
Operation arm and hydraulic control valve
It can be arranged in a width dimension.
While suppressing the size increase in the horizontal direction,
This is effective for downsizing the case in the width direction.
You.

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

(Structure) The work vehicle according to the second aspect of the present invention includes
At the top of the transmission case, there is a
Arm and the lift arm
When a position lever for raising and lowering the working device is provided
Both, an operation arm interlocked with the lift arm and
Oil that drives and swings the lift arm via its operating arm
The pressure cylinder is installed in the transmission case, and
Control valve for position control of hydraulic cylinders
In the work vehicle in which the position lever is provided,
Arm for setting the position of the lift arm linked to the motor
And a feedback interlocked with the lift arm
Rotating arms and connecting these rotating arms to a hydraulic control valve.
And a balance swing link that is dynamically connected to the transmission case.
Inside each of the hydraulic cylinders
Overlap in the hydraulic Shea Linda and the lateral side view in
And the swing range of the operation arm is
Sideways so as to overlap with the hydraulic control valve in side view
And the two pivoting arms and the balance swinging
Position the arm forward of the fuselage with respect to the operation arm.
In addition, the two rotating arms, the balance swing link, and
The operation arm can swing back and forth around the horizontal axis of the fuselage.
The hydraulic cylinder and the operating arm connected thereto are eccentrically arranged on one side from the left and right center of the fuselage, and the two rotating arms and the balance Dynamic links are deployed
And features.

(Operation) According to the above configuration, the mission
In the case, a hydraulic cylinder and
The moving arm and the balance swinging link are arranged side by side,
The operation arm and the hydraulic control valve are arranged side by side behind these
It is arranged in a state. With such a configuration,
Make effective use of the front, rear, left and right spaces in the case
To reduce the dead space.
I am doing it. In addition, machines that are arranged side by side
The combination of instruments is located on the front side in the transmission case.
Hydraulic cylinder with a relatively large left and right width and
Left and right by being provided to be able to swing back and forth around the axis
Combination of side-by-side arrangement of small rotating arms
On the rear side in the transmission case,
Hydraulic control valve with large right width and swing back and forth around the horizontal axis of the aircraft
The operation door with a small left and right width
To adopt a combination that arranges
Therefore, when arranging things with wide left and right width side by side
The space occupied in the horizontal direction can be reduced compared to
Wear. Hydraulic cylinder, both rotating arms and balance swinging ring
And are arranged side by side, so when viewed from the side
It is possible to arrange to overlap, the operation arm
And the hydraulic control valve are arranged side by side, so the side
It is possible to arrange them so that they overlap in view.
Therefore, install these devices without overlapping in the vertical direction
Occupies less space in the vertical direction than when
Wear. In addition, the eccentricity of the hydraulic cylinder and the operation arm can expand the space for disposing the hydraulic control valve and the like at the opposite side, and can also increase the hydraulic cylinder and the operation arm, the hydraulic control valve and the rotation arm, and the like. Can be arranged on the left and right in a well-balanced manner.

(Effect) Therefore, according to the second aspect of the invention,
Equipment is arranged evenly across the front, back, left and right inside the case
And side-by-side sets focusing on the left and right width of each device
Occupied space in the front, back, left, right, up and down directions
A short length of front-rear
Can be demonstrated on small models with
I came to be able to. Also, in the upper part of the transmission case, it is possible to arrange control valves and other components within the limited horizontal width without any difficulty, making it possible to further reduce the size in the horizontal direction, which is effective for application to small machines. Becomes

[0013]

Embodiments will be described below with reference to the drawings. FIG.
Fig. 1 shows a riding cultivator as an example of a working vehicle. This tiller has a three-point link mechanism 1
And the rotary tillage device 2 is connected so as to be able to move up and down freely. The transmission system is configured to transmit the power of the engine mounted on the front of the fuselage to the front and rear wheels via the transmission case 4, and the tilling device 2 is driven via a power take-off shaft.
The transmission system is configured to drive the motor. A driving seat 8 is provided between the left and right rear wheel fenders 7 and 7, and a hydraulic cylinder 9 disposed below the driving seat 8 and above a rear portion of the transmission case 4 is driven to swing around a horizontal axis. The left and right lower links 11, 11 of the three-point link mechanism 1 are lifted up and down by a pair of left and right lift arms 10, 10 to drive up and down the tilling apparatus 2.

At the rear of the driver's seat 8, a fall prevention frame 36 formed in a loop shape when viewed from the front is provided upright. The fall prevention frame 36 is, as shown in FIG. A U-shaped upper frame portion 36c is detachably inserted and connected to upper ends of left and right lower frame portions 36a and 36b which are separately attached and fixed to side surfaces. The left and right lower frames 36a, 36
The upper ends of b are connected to each other by a connection frame 36d and reinforced.

As shown in FIGS. 5 and 6, the left and right rear wheel fenders 7 and 7 are provided with various operation levers 12 to 15 operable in the front-rear direction. The lever guide portion 16 at the position where the fender 7 is to be formed is integrally formed with the fender 7. That is, a fender 7 formed of a sheet metal material has a long hole 1 having both ends bulging in an arc shape.
7 is formed by punching, and the left and right straight edge portions are bent downward to form the lever guide portion 16. In addition, the lever guide part 1 in each operation lever
A resin-made soundproof tube 18 is externally fitted to the sliding contact with the tube 6.

As shown in FIG. 1, the hydraulic cylinder 9
Is an operating arm in which a hydraulic piston 20 is provided on the inner surface of the cylinder case 19, and a rear upper portion of the transmission case 4 is formed as a cylinder case 19, and is pivotally connected to the distal ends of the piston rod 21 and the piston rod 2. The rotation drive shaft 23 of the lift arms 10, 10 supported on the cylinder case 19 around the axis of the horizontal axis via 22 is configured to rotate. The operation arm 22 is configured to limit the ascending operation limit of the lift arms 10 and 10 by a slightly elastically deformable plate member 24 attached to the inner wall of the transmission case 4. As shown in FIG. 2, the operation arm 22 is fitted around the rotation drive shaft 23 at the center position in the left and right direction so as to be freely rotatable integrally, and the swing end side is bent and formed to one side, and the hydraulic cylinder 9 and the hydraulic cylinder 9 are formed. Eccentric to the horizontal side from the left and right center of the fuselage, and the hydraulic cylinder 9
Also, it is eccentrically arranged from the left and right center of the fuselage to one side.
The hydraulic control valve 25 for the hydraulic cylinder 9
Are provided in a state opposite to the eccentric direction of the hydraulic cylinder 9 so as to enter the inside of the transmission case 4.
In other words, a hydraulic pressure is applied to the lower surface side of the mounting portion 19 a formed in the cylinder case 19 at a position near the lateral side of the pivot connection point between the piston rod 21 and the operation arm 22 operated in accordance with the driving of the hydraulic cylinder 9. Apply control valve 25,
The hydraulic control valve 25 is attached and fixed from below by an insertion bolt 26. The hydraulic control valve 25 is provided with a rear wheel differential mechanism 27.
In this case, the input bevel gear 27a, which is arranged to be deviated from the left and right center position of the fuselage, is arranged so as to be deviated to the opposite side to avoid the interference with the drive gear mechanism in the transmission case 4, and to clear the empty space in the transmission case 4. They are used effectively.

The operation of the position lever 12 disposed on the side of the driver's seat 8 causes the position lever 1 to move.
2 at the anti-aircraft level corresponding to the operation position 2
Is provided with a position control mechanism for controlling the position. As shown in FIGS. 3 and 4, the spool 28 of the hydraulic control valve 25
Is configured to be slid along the body longitudinal direction, and is pushed forward and backward with the rotation of the rotation arm 12a of the position lever 12 and the lift arm 10 held at an arbitrary operation position by the disc spring 29. The rotation operation shaft 30a of the feedback link 30 to be pulled is
Each of the rotary operation shafts 12 is supported so as to be rotatable around a horizontal axis in the vicinity of a side of the hydraulic cylinder 9 where the hydraulic control valve 25 is disposed.
A balance swinging link 33 in which rotating arms 31 and 32 attached to a and 30a are pivotally supported at both ends is provided at a lateral position of the hydraulic cylinder 9 in a vertical posture. The intermediate fulcrum portion of the balance swinging link 33 and the valve spool 28 are pivotally connected by a relay link 34 in a vertical position in which the balance is rotated around a horizontal axis. The intermediate portion of the relay link 34 is supported by a bracket 35 attached to the front side surface of the hydraulic control valve 25 so as to be rotatable about a horizontal axis X.

When the position lever 12 is moved up or down, the balance swing link 33 is swung about the axis of the rotary operation shaft 30a of the feedback link 30, and the relay link 34 is thereby supported. By swinging around X, the valve spool 28 is operated to a position corresponding to the operation direction, and the lift arm 10 is moved up and down. As a result, the feedback link 30 is pushed and pulled,
The rotation arm 30a of the feedback link 30 rotates to lift the lift arm 10 to a position corresponding to the lever operation position.
Is lifted and lowered, mechanical feedback control is performed so as to return the valve spool 28 to the neutral position, and the position control is performed so that the tillage device 2 has an anti-machine height corresponding to the lever operation.

In the claims, reference numerals are provided to facilitate comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a side view of a hydraulic control valve disposition portion.

FIG. 2 is a front view of a hydraulic control valve disposition portion.

FIG. 3 is a front view of a position control link mechanism.

FIG. 4 is a side view of the relay link.

FIG. 5 is a plan view of the driving unit.

FIG. 6 is a sectional view of a lever guide section.

FIG. 7 is a rear view showing the mounting structure of the overturn prevention frame.

FIG. 8 is an overall side view of a riding type tiller.

[Explanation of symbols]

 4 Transmission Case 9 Hydraulic Cylinder 10 Lift Arm 12 Position Lever 22 Operating Arm 25 Hydraulic Control Valve 28 Spool 31 Rotating Arm 32 Rotating Arm 33 Balance Swing Link 34 Relay Link

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-123420 (JP, A) JP-A-59-88008 (JP, A) JP-A-57-202205 (JP, A) 68705 (JP, U) Japanese Utility Model 4-108455 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) A01B 63/10 B60K 20/02

Claims (2)

(57) [Claims] 1. Above the transmission case (4) at the rear of the fuselage
A lifting arm (10) for lifting and lowering the working device.
A hydraulic cylinder (9) that oscillates is provided, and
Hydraulic control valve for this hydraulic cylinder (9) in the vicinity of
A work vehicle provided with (25), wherein the lift truck is pivotally connected to the hydraulic cylinder (9).
Operating arm (22) for driving the arm (10) and its operation
Input mechanism for the differential mechanism located below the operation arm (22).
A bell gear (27a) is connected to the hydraulic control valve (25).
Then, the swing range of the operation arm (22) and the input
The bell gear (27a) and the hydraulic control valve (25)
And placed side by side so that they overlap in side view,
The operation arm (22), the input bevel gear (27
a) and each of the hydraulic control valves (25)
The operation arm is located in the case (4).
The axis of the upper rotation drive shaft (23) of (22) is
The hydraulic cylinder (9), the operating arm (22),
The input bevel gear (27a) is set at a position
Eccentrically to the side
A work vehicle provided with the hydraulic control valve (25). 2. On a transmission case (4) at the rear of the fuselage.
A lifting arm (10) for lifting and lowering the working device;
The work is located in front of the lift arm (10).
A position lever (12) for raising and lowering the device is provided.
Operation in conjunction with the lift arm (10)
Via the arm (22) and its operating arm (22)
Hydraulic cylinder that drives and swings lift arm (10)
(9) is installed in the mission case (4), and
Position control oil for the hydraulic cylinder (9)
A work vehicle having a pressure control valve (25) therein, the lift being operatively connected to the position lever (12).
A rotating arm (31) for setting an arm position, and the lift
A feedback loop interlocked with the arm (10)
Moving arm (32), these rotating arms (31), (3
2) Linking the hydraulic control valve (25 ) with the hydraulic control valve (25)
(33) is provided in the transmission case (4).
In the horizontal position on the side of the hydraulic cylinder (9), respectively.
Overlap with the hydraulic cylinder (9) in side view.
And the operating arm (22) is
Swing range of the hydraulic control valve (25) and side view
Side by side so that they overlap each other.
(31), (32) and the balance swing link (33)
Is located on the forward side of the fuselage with respect to the operation arm (22).
And the two rotating arms (31), (32),
The balance swing link (33) and the operation arm (2
2) is provided so as to be able to swing back and forth around the horizontal axis of the fuselage, and the hydraulic cylinder (9) and the operating arm (22) connected to the hydraulic cylinder (9) are arranged eccentrically to one lateral side from the left and right center of the fuselage, A work vehicle in which the two rotating arms (31) and (32) and the balance swing link (33) are arranged at a position opposite to an eccentric side of a hydraulic cylinder .