JPH0729775Y2 - Lift arm support structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lift arm support structure for supporting and elevating a working machine in a vehicle equipped with the working machine such as an agricultural work vehicle.

2. Description of the Related Art An example of a conventional lift arm support structure (Japanese Utility Model Laid-Open No. 54-18420) is shown in FIG.

The housing 01 rotatably supports the main shaft 02 through a pair of left and right cylindrical bodies 03 spline-fitted to the main shaft 02 in the left and right cylindrical portions 01a and a bearing metal 04 provided on the outer peripheral surface thereof. There is.

The pair of left and right tubular bodies 03 extend in the respective directions, and the main shaft 02
The crank arm 05, which is spline-fitted at the center of, is positioned centrally.

Lift arms 06 are spline-fitted to both ends of the main shaft 02 protruding left and right from the housing 01, and a disk-shaped stopper 07 for preventing the lift arm 06 from coming off is attached to the main shaft 02 by a bolt 08.
It is fixed on both sides of.

Inner surface of the fitting part of the lift arm 06 and the cylindrical part of the housing 01
A collar 09 is interposed between the outer surface of 01a.

As described above, the crank arm 05 is rotated by the cylindrical body 03.
The left and right lift arms 06 are positioned substantially at the center of 02, and are sandwiched between the housing 01 and the stopper 07 via the collar 09 so as to be positioned at both ends of the main shaft 02.

The force of the hydraulic cylinder is transmitted to the crank arm 05, and when the crank arm 05 swings, the main shaft 02 that is spline-fitted with the crank arm 05 is rotated, and the rotation of the main shaft 02 is also lifted to be spline-fitted with the main shaft 02. By swinging the arm 06, the working machine attached to the lift arm 06 can be moved up and down.

Problems to be Solved If the force of the hydraulic cylinder applied to the crank arm 05 includes a component in the axial direction of the main shaft, the crank arm 05 slides in the axial direction with respect to the main shaft 02, and the crank arm 05 slides. Moves the cylindrical body 03 on which the crank arm 05 has been positioned, and an axial force is applied to the lift arm 06 via the collar 09 and to the spindle itself via the stopper 07.

The lift arm 06 that raises and lowers the work machine may receive an axial force of the main shaft 02 depending on the work situation.
In this case, a force is applied to the crank arm 05 via the collar 09 and the tubular body 03, and at the same time, the main shaft 02 is passed through the stopper 07.
Also, the axial force is applied.

In this way, the axial force received by the crank arm 05 and the lift arm 06 acts on the main shaft 02 as an axial load, and therefore, if a load that is repeatedly applied is applied to the main shaft 02, the wear of the collar 09 is promoted and the collar 09 is accelerated. If it wears, the lift arm 06 and the crank arm 05 will be rocked.

Means and Actions for Solving the Problems The present invention has been made in view of the above point, and its object is to ensure smooth swinging as a structure in which the axial force received by the crank arm and the lift arm is held by the casing. The point is to provide a support structure for a lift arm that enables

That is, the present invention provides a lift arm support structure in which a crank arm is spline-fitted to the center of a main shaft rotatably supported by a casing, and the lift arms are spline-fitted to both ends of the main shaft so as to be spline-fitted to both ends of the main shaft. The casing forms a cylindrical portion between the crank arm and the lift arm to support the main shaft, and a washer is interposed between the inner surface of the cylindrical portion and the side surface of the fitting portion of the crank arm to form a cylinder of the casing. It is a support structure of the lift arm in which a washer is interposed between the outer surface of the portion and the inner surface of the fitting portion of the lift arm.

Since a washer is interposed between the inner side surface of the cylindrical portion of the casing and the side surface of the crank arm fitting portion, even if the crank arm receives an axial force, force is applied to the casing via the washer and Has no force.

Further, since the washer is interposed between the outer surface of the cylindrical portion of the casing and the inner surface of the lift arm fitting portion, even if the lift arm receives an axial force, a force is applied to the casing via the washer and the main spindle No force acts on.

Therefore, the main shaft is always stably supported by the casing, and the crank arm and the lift arm can be swung smoothly at all times.

The washers may be colored.

Embodiment An embodiment according to the present invention shown in FIGS. 2 and 4 will be described below.

This embodiment is an example applied to a work machine lifting device for an agricultural work vehicle, and FIG. 2 is a partial perspective view of the agricultural work vehicle.

A rotary cultivator 53, which is a working machine, is provided behind the rear body 52 between the left and right rear wheels 51 of the work vehicle 50 via a link member.

Bracket 54 protruding rearward from the rear surface of the rear body 52
One end is pivotally attached to the tip of the upper link 55 to extend further rearward, and a pair of left and right lower links 56 pivotally attached to the left and right side surfaces of the rear body 52 extend rearward.
The rotary cultivator 53 is swingably supported up and down by links 55 and 56 of the book.

A working machine lifting device is provided above the rear body 52, and a main shaft 5 is rotatably supported by a casing 1a extending from the hydraulic cylinder 1, and both ends of the main shaft 5 projecting left and right from the casing 1a. The base end of each lift arm 9 is spline-fitted.

The lift arm 9 spline-fitted to the main shaft 5 extends rearward, and a connecting link 57 is installed substantially vertically between the tip of the left lift arm 9 and the lower link 56 therebelow.
A cylinder 58 is suspended from the tip of the right lift arm 9, and a rod 59 extending downward is connected to a lower link 56 below the cylinder.

Therefore, the lift arm 9 is swung by the rotation of the main shaft 5, and the connecting link 57 and the cylinder connected to the lift arm 9 are connected.
By swinging the lower link 56 up and down via the rod 58 and the rod 59, the rotary cultivator 53 can be moved up and down.

A cylinder 58 provided between the right lift arm 9 and the lower link 56 can tilt the rotary cultivator 53 according to the inclination of the ground by adjusting the protruding length of the rod 59.

Lift arm 9 in the lifting mechanism of the working machine as described above
The support structure of is shown in FIGS. 3 and 4.

Reference numeral 1 is a hydraulic cylinder, and a connecting rod 3 extends from a piston 2 that slides inside the hydraulic cylinder.

A main shaft 5 is rotatably supported via a collar 4 inside a casing 1a extending from the hydraulic cylinder 1 and bulging upward.

The main shaft 5 has spline shafts 5a and 5b formed at the center and both ends thereof, and the cylindrical portion 1b formed at the left and right end portions of the casing 1a is a cylindrical portion between the central spline shaft 5a and the end spline shaft 5b. Is supported via a collar 4, and the cylindrical portion
A ring-shaped dust seal 13 is fitted between the main shaft 5 and the inner peripheral surface near the side surface of 1b.

The crank arm 6 is spline-fitted to the central spline shaft 5a of the main shaft 5 at its one end cylindrical portion 6a,
A washer 7 is interposed between the left and right side surfaces of the cylindrical portion 6a and the inner side surfaces of the left and right cylindrical portion 1b of the casing 1a.

The washer 7 may be colored.

The other end of the crank arm 6 is bifurcated, and the end of the connecting rod 3 is sandwiched between the bifurcated portions 6b, and a pivot 8 penetrates both ends to rotatably connect them.

Main shaft 5 protruding outward from the left and right cylindrical portions 1b of the casing 1a
A lift arm 9 is spline-fitted to both end spline shafts 5b at its base end 9a, and a washer is provided between the inner surface of the base end 9a and the outer surfaces of the left and right cylindrical parts 1b of the casing 1a. 10 are installed.

This washer 10 may also be color.

Stop plates 11 are fitted into grooves provided in the circumferential direction at both ends of the main shaft 5 to prevent the lift arm 9 from coming off the main shaft 5.

The stop plate 11 is screwed to the lift arm 9 with a bolt 12,
It swings integrally with the lift arm 9 for smooth movement.

In this embodiment, the lift arm support structure is as described above, and the lift arm 9 is provided with a washer 10 through a casing.
The crank arm 6 is axially positioned by the outer surfaces of the left and right cylindrical portions 1b of the casing 1a, and the crank arm 6 is inserted through a washer 7 into the casing.
Axial positioning is performed by the inner surface of the cylindrical portion 1b of 1a.

When the piston 2 of the hydraulic cylinder 1 slides, the connecting rod 3
The crank arm 6 swings via the
The rotation of the main shaft 5 spline-fitted to the crank arm 6 causes the main shaft 5 and the lift arms 9 spline-fitted at the left and right ends of the main shaft 5 to swing up and down, thereby rotating the rotary tiller. The machine 53 can be moved up and down.

Normally, the force applied from the connecting rod 3 to the crank arm 6 is a force in a direction perpendicular to the axial direction of the main shaft 5, but it may include a slight axial force component. On the other hand, it slides slightly in the axial direction, and a force acts on the inner surface of the cylindrical portion 1b of the casing 1a via the washer 7.

Therefore, no axial force is applied to the main shaft 5.

Further, depending on the working condition of the rotary cultivator 53, a force in the axial direction of the main shaft 5 may be applied to the lift arm 9. For example, when a leftward force is applied to the lift arm 9 in FIG. Causes a force to act on the outer surface of the right cylindrical portion 1b of the casing 1a via the washer 10, and conversely when a rightward force is applied to the lift arm 9, the left lift arm 9 causes the washer 10 to move to the casing 1a. A force is applied to the outer surface of the left cylindrical portion 1b, and in any case, the force applied in the axial direction of the lift arm 9 acts on the casing 1a via the washer 10.

As described above, since the axial force applied to the crank arm 6 and the lift arm 9 is received by the casing 1a, it does not act on the main shaft 5, so that the swinging of the crank arm 6 and the lift arm 9 does not cause rattling. It always goes smoothly.

Even if the washers 7 and 10 are worn to some extent, the axial force of the crank arm 6 and the lift arm 9 is always received by the casing 1a, so that smooth movement is guaranteed for a long period of time.

Effect of the Invention According to the present invention, since all the axial force of the main shaft applied to the lift arm and the crank arm is received by the casing via the washer, the main shaft is not affected and the lift arm and the crank arm are always affected. The movement of can be performed smoothly.

[Brief description of drawings]

FIG. 1 is a sectional view showing a conventional lift arm support structure, FIG. 2 is a partial perspective view of an agricultural work vehicle equipped with a lifting device according to an embodiment of the present invention, and FIG. 3 is a lift in the lifting device. FIG. 4 is a side sectional view showing an arm support structure, and FIG.
It is a IV-IV sectional view. 1 ... Hydraulic cylinder, 1a ... Casing, 1b ... Cylindrical part, 2 ... Piston, 3 ... Connecting rod, 4 ... Collar, 5 ... Main shaft, 5a ... Central spline shaft, 5b ... End spline Shaft, 6 ... Crank arm, 6a ... Cylindrical part,
7 ... washer, 8 ... axis, 9 ... lift arm, 9a
…… Base end, 10 …… washer, 11 …… stop plate, 12 …… bolt, 13 …… dust seal, 50 …… agricultural work vehicle, 51 …… rear wheel, 52 …… rear body, 53 …… rotary Cultivator, 54 ……
Bracket, 55 …… upper link, 56 …… lower link, 57 …… connecting link, 58 …… cylinder, 59 …… rod.

Claims (1)

[Scope of utility model registration request] 1. A lift arm support structure in which a crank arm is spline-fitted in the center of a main shaft rotatably supported by a casing, and the lift arms are spline-fitted to both ends of the main shaft so that the lift arms are spline-fitted at both ends of the main shaft. ,
A casing forms a cylindrical portion between the crank arm and the lift arm to support the main shaft, and a washer is interposed between the inner surface of the cylindrical portion and the side surface of the fitting portion of the crank arm,
A support structure for a lift arm, characterized in that a washer is interposed between the outer surface of the cylindrical portion of the casing and the inner surface of the fitting portion of the lift arm.