JPH0635861Y2 - Movable device of steering lever in loader - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a steering lever in a skid steer loader (hereinafter, simply referred to as a loader) that employs a hydrostatic transmission (hereinafter, referred to as HST) as a drive device. The present invention relates to a movable device capable of adjusting lateral movement of a lever.

[Conventional technology]

The external appearance of the loader equipped with the HST is as shown in FIG. 4, and the drive device of this loader 1 uses the method of transmitting energy by the change of hydraulic pressure as its principle, and drives the hydraulic pump by the engine. The wheels are driven by rotating the hydraulic motor by the hydraulic pressure generated by the hydraulic pump. More specifically, as shown in FIG. 5, a tandem type hydraulic pump 2 formed by arranging two axial piston type pumps 3 coaxially with each other and an engine 4 are provided.
Output shaft 5 is directly connected as a rotary shaft, each axial piston type pump 3 is connected to a hydraulic motor 7 via a high pressure pipe 6, and each hydraulic motor 7 is further connected via a chain final decelerator 8 to the left and right sides. It is connected to the wheel 9 of.
As is generally known, although not shown, the axial piston pump 3 has a plurality of cylinders in a cylinder block which are directly connected to the output shaft 5 of the engine 4 and are rotated on the same circumference. The base end of the piston rod that is arranged in the axial direction and extends from each cylinder is supported by a swash plate via a ball joint.By changing the inclination of the swash plate, the discharge amount of hydraulic fluid and the flow direction can be changed. To do. Especially when the swash plate is perpendicular to the axis,
Since there is no volume change between the piston and the cylinder, the discharge amount becomes zero, which is the so-called neutral state. An orbit motor is adopted as the hydraulic motor 7, and by changing the discharge amount and the flow direction of the axial piston pump 3, the rotation speed and the rotation direction of the wheels 9 on each side together with the hydraulic motor 7 are changed independently. be able to. in this way
The loader 1 equipped with the drive device 10 by the HST can perform a unique driving operation by adjusting the inclination of the swash plate of each axial piston type pump 3.

Then, such a driving operation is performed by a pair of steering levers 20 provided upright on the left and right of the driver's seat. As shown in FIGS. 6 and 7, a bracket 24 is attached to the panel 22.
The steering levers 20 are fixed to the respective rotary shafts 28 rotatably supported via the bearings 26 and the bearings 26, and independent rotary motions of the rotary shafts 28 based on the driving operation are linked. It is transmitted to a trunnion lever 32 for varying the swash plate inclination angle of each axial piston type pump 3 via the mechanism 30.

[Problems to be solved by the invention]

As described above, in the steering device of the loader,
Since the left and right steering levers are independently provided, both hands are always required for the driving operation, and the driver's fatigue level tends to increase.

In addition, the left and right steering lever positions are immovable, which forces drivers of different sizes to have unnatural driving postures, and this further increases the fatigue. Has become.

An object of the present invention is to solve the problem that the steering lever is movable and the movement of the steering lever can be adjusted in the left-right direction so that an optimal lever position can be selectively secured for the driver.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention mounts a steering lever by allowing only a movement in the axial direction with respect to a rotating shaft, and equips the steering lever with locking means for restraining the above-mentioned axial movement. At the same time, the locking means disengages the crimp by engaging a braking piece having a close curved surface that is crimped by a spring bias on the surface of the rotating shaft and the steering lever that is articulated with the braking piece. A new technical measure consisting of the operating lever and

A tubular boss portion formed on the base of the steering lever is fitted to the rotating shaft, and a smooth movement is allowed only in the axial direction due to, for example, a convex strip extending in the axial direction. The locking means that is connected to the steering lever and holds the steering lever at a desired position is provided in a form substantially parallel to the steering lever, and in particular, the operation lever is braked by gripping or releasing the steering lever with the steering lever. It is placed near the steering lever so that the pieces can be disengaged and crimped.

[Action]

In the steering lever turning device described above, the operation lever of the locking means is carried from a normal driving posture, and the movement of the steering lever can be adjusted by a simple operation such that a grip force is applied to the operation lever. If the operation lever is released at the optimum adjustment completion position, the close curved surface of the braking piece will be pressed against the surface of the rotating shaft, and the strong locking action by frictional force will stabilize the steering lever at the adjustment completion position. Can be held.

〔Example〕

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. Since the movable devices related to the left and right steering levers are basically the same, only the one steering lever will be described below including the drawings.

In the figure, 50 is a fixed shaft having both ends fastened to the left and right frames 52, 52, and bearing shafts 54a, 54b are attached to the center and both ends of the fixed shaft 50 to form a pair of left and right rotating shafts. 58, 58 are supported by bearings 56 fitted in the bearing boxes 54a, 54b,
Independent rotation is allowed for each. Steering levers 60, 60, which are bilaterally symmetrical and have a curved rod shape, are fitted on the two rotary shafts 58, 58 via a cylindrical boss portion 60a formed on the base. In the movement adjusting range of the steering lever 60 on the rotating shaft 58, a convex member 61 (not shown), such as a sliding key, extending in the axial direction is fixed.
The steering lever 60 is allowed to move only in the axial direction on the rotary shaft 58 while maintaining the upright state through the tubular boss portion 60a having a groove that slides with this.

Reference numeral 62 denotes a locking means provided in parallel with the steering lever 60 in order to restrain the axial movement of the steering lever 60, and the locking means 62 has a handle 64a at its tip and an intermediate portion. Is a lever-shaped operation lever 64 pivotally supported above the steering lever 60, and on the other hand, has a close-fitting curved surface 66a that can be crimped to the surface of the rotating shaft 58 at the tip, and the middle part of the steering lever 60 A plate-like braking piece 66 that is also pivotally supported at a lower position is provided, and the base ends of the operating lever 64 and the braking piece 66 are articulated by a connecting rod 70 via crevasses 68, 68, respectively, so that they can be finely adjusted. Has been done. Reference numeral 72 is a tension coil spring stretched between the vicinity of the base end of the braking piece 66 and the steering lever 60, and the dense curved surface 66a is pressure-bonded to the surface of the rotating shaft 58 to give frictional resistance to the interface. It is a thing. In this case, the densely curved surface 66a may be covered with a resin film or the like having a large friction coefficient to further enhance the locking action by the densely curved surface 66a.
Further, although not shown, a suitable number of saw-toothed annular grooves are formed in the axial direction of the rotating shaft 58, and mechanical restraining means such as engaging the braking piece 66 with this is used together. May be.

The rotating shaft 58 is a lever 7 that is planted on the rotating shaft 58.
4, a joint 76, a rod 78, and a series of link type transmission mechanisms 80, which are interlocked with a trunnion lever 82 for varying the swash plate inclination angle of the axial piston type pump 84. Along with the configuration of the neutral device 86 of the steering lever 60 with the built-in, it does not go out of the conventionally known range.

The steering lever by the device of the present invention as described above
When the 60 is moved to a desired position, the hand holding the steering lever 60 is slightly shifted downward and the handle 64a of the operation lever 64 is brought, and a grip force is applied to this to bring the operation lever 64 into operation. Is rotated in the P arrow direction. This rotation resists the urging force of the tension coil spring 72 through the connecting rod 70 and the braking piece.
Since 66 is rotated in the direction of the arrow Q, the pressure-bonding or locking action of the close-fitting curved surface 66a against the surface of the rotary shaft 58 is released, and the steering lever 60 is guided on the rotary shaft 58 by the guide of the protrusion 61. It can be moved to any position left or right.
After that, when the driver releases the operating lever 64 that was brought in at the optimum adjustment completion position selected by the driver, the braking piece 66 and the operating lever 64 both return in the opposite arrow direction by the biasing force of the tension coil spring 72. The tightly curved surface 66a again presses against the surface of the rotating shaft 58, and the steering lever 60 is stably held at the adjustment completion position by the strong locking action by the frictional force.

It is needless to say that the steering lever 60 is fitted to the rotating shaft 58 by the protrusion 61 so as not to rotate relative to it, so that the pump control can be performed by operating the lever as in the conventional case.

[Effect of device]

Since the movable device of the steering lever in the hydrostatically driven skid steer loader according to the present invention has the above-described structure and operation, the optimum steering lever position for each driver can be selected at any time by simple hand operation.
It is extremely effective in alleviating the overwork problem of the driver, which has been neglected due to the two-handed operation and the special running mode. Moreover, since the free movement of the steering lever is strongly restrained by the frictional force of the locking means,
Vibrations and noises unique to the lever due to machine base vibrations are also effectively prevented.

[Brief description of drawings]

1 is a front view corresponding to the BB cross section of FIG. 2 showing an embodiment of the device of the present invention, FIG. 2 is a side view of the AA cross section of FIG. 1, and FIG. FIG. 4 is a side view showing a connection relationship with a pump, FIG. 4 is a side view of a general loader, FIG. 5 is a schematic explanatory view of a drive device by HST, and FIG. 6 is a front view showing a mounting state of a conventional steering lever. ,
FIG. 7 is a side view of the same. 58 ... Rotating shaft, 60 ... Steering lever 61 ... Projection element, 62 Locking means 64 ... Operating lever, 66 ... Brake piece 66a ... Dense curved surface, 72 ... Tension coil spring 82 ... Trunnion lever 84 ... Axial piston type pump

Claims (1)

[Scope of utility model registration request] 1. A hydraulic pump and a hydraulic motor are controlled by operating a rotary shaft that cooperates with each of a pair of steering levers and a trunnion lever that is interlockingly connected to the rotary shaft via a transmission system. In the hydrostatically driven skid steer loader that allows the wheels to be driven independently,
The steering lever is fitted so as to allow only movement in the axial direction with respect to the rotating shaft, and the steering lever is provided with locking means for restraining the axial movement.
The locking means includes a braking piece having a close curved surface which is pressed against the surface of the rotating shaft by spring bias, and an operating lever which is connected to the braking piece and grips the steering lever together to release the pressing force. A movable device of a steering lever in a loader comprising: