JP3176646U - Tilt-type steering unit - Google Patents

Abstract

A steering unit having a tilt function is configured to easily set a precise angle of a column shaft in accordance with an operator's working state.
A base portion 14 fixed to a cab floor X of a work vehicle is provided, and a column shaft 10 is supported by a base portion 14 at a base end side so that the front end side can be rotated back and forth, and a lock cylinder 12a. Is provided between the base portion 14 and the intermediate portion of the column shaft 10 and includes a lock mechanism 12 that fixes the standing angle of the column shaft 10. The operator can lock the column shaft 10 by pressing the operation lever 12 b of the lock mechanism. In the tilt type steering unit 1A, which is released and the column shaft 10 is urged in the standing direction and the distal end is freely rotatable, and is brought into a locked state by returning the pressing, the operation lever 12b is attached to the base portion 14 side. In addition, the pedal 122 has a height from the floor surface X that can be operated from the ankle point while the operator puts his heel on the floor.
[Selection] Figure 1

Description

  The present invention relates to a steering unit having a tilt function in the front-rear direction, and more particularly to a tilt-type steering unit standing on a driver's cab floor of a wheeled work vehicle such as a hydraulic excavator.

  In a work vehicle such as a hydraulic excavator, a wheel traveling type vehicle generally uses a steering device provided with a handle at the end of a column shaft for steering during traveling. It is necessary to set the standing angle of the column shaft, which is the axis of this steering device, to an angle that can ensure an optimum driving position according to the physique of the operator. In a work vehicle such as a construction machine, a plurality of levers for operating the machine are provided in the cab, and the handle may get in the way when getting on and off and operating.

  Therefore, as described in Japanese Patent Laid-Open No. 10-181614, as in the steering unit 1B for a construction machine shown in FIG. 6, the column having the handle 31 side pivotable back and forth and the lower end pivotally supported on the floor side. A tilting type equipped with a lock mechanism 32 for fixing or releasing the fixing of the shaft 30 at an arbitrary angle by a lock means (clamping means) 32a by operating an operation lever 32b is widely adopted.

  The steering unit 1B operates the operation lever 32b to unlock the lock means 32a, thereby making the front end of the column shaft 30 rotatable in the front-rear direction so that the operator holds the handle 31 and makes any desired After the angle is changed, the column shaft 30 can be set to a desired angle by fixing the column shaft 30 again by operating the operation lever 32b. Even when the handle 31 gets in the way when getting on and off, or operating, by releasing the lock, the handle 31 can be tilted forward to secure a wide space in front of the operator.

  However, the steering unit 1B needs to reach to the middle portion of the column shaft 30 in order to operate the operation lever 32b, which forces the operator to bend forward and be extremely cramped. For this reason, if the lever is operated in a forward bent position after the driving position is determined, the angle of the column shaft 30 once determined is likely to shift and it becomes difficult to set the optimal angle.

  Further, a work vehicle such as a hydraulic excavator needs to be able to secure a front lower view in order to perform excavation work or the like. As shown in the front view of the steering unit 1B in FIG. Since the locking mechanism 32 having the operation lever 32b and the locking means 32a protrudes laterally and occupies a relatively large space in the middle portion, the operator's work view is greatly blocked.

  On the other hand, as described in JP-A-11-334605 and a steering unit 1C shown in FIG. 5, a lock mechanism 42 having an operation lever 42b is provided on the lower end side of the column shaft 40, and the operator A is in a sitting posture. A method of operating the operation lever 42b with a foot has been proposed, and the driving position can be set without forcing the operator A to be cramped.

  In this steering unit 1C, a lock cylinder 42a also serving as a lock means is provided so as to urge the column shaft 40 forward via the link means, and the column shaft 40 is automatically raised by a lock release operation. The operator A can set the angle of the column shaft 40 with one hand while operating the operation lever 42b. Further, since the lock mechanism 42 is on the lower end side of the column shaft 40, the hindrance to visibility is relatively small.

  However, although the steering unit 1C is a system in which the operation lever 42b is operated with a foot, as shown in the figure, since the operation portion is at a relatively high position away from the floor board, the operator A is in a posture in which one leg is lifted. The operation will be performed. Therefore, when the standing angle of the column shaft 40 is set in detail while operating the operation lever 42b, lifting the foot as shown in the figure forces the operator A to have an unnatural posture. Precise setting becomes difficult. In addition, when the operator A is in a standing posture for work, the posture becomes more unstable because one leg stands when the angle of the column shaft 40 is changed.

JP-A-10-181614 Japanese Patent Laid-Open No. 11-334605

  The present invention is intended to solve the above-described problems. For a steering unit of a work vehicle having a tilt function in the front-rear direction, a precise angle of the column shaft corresponding to various work conditions of the operator. It is an object to make setting easy.

  Therefore, the present invention includes a base portion that is fixed to the floor surface of the cab of the work vehicle, and the base end side of the base shaft in a state where the column shaft having the handle is rotatable within a predetermined range in the front-rear direction. A fluid pressure cylinder is supported between the base part and the middle part of the column shaft, and is installed at an arbitrary angle with respect to the floor surface of the column shaft. A locking mechanism for fixing is provided at a predetermined position, and when the operator depresses the operation lever of the locking mechanism, the lock is released and the column shaft is urged in the upright direction so that the front end side can be rotated freely. In the tilt type steering unit where the standing angle is locked by returning it, the operation lever is attached to the base part side, and the operation part allows the operator to place his / her foot on the floor surface. It is ankle while only the height from the floor surface operable in the previous movement, and shall be characterized in that.

  In this way, in the tilt type steering unit that sets the angle of the column shaft by operating the operation lever, the standing angle can be operated by operating the operation lever from the ankle down so that a delicate touch can be exerted with the heel on the floor. By adopting a configuration for releasing the fixing, the angle of the column shaft can be easily adjusted without impairing other work operations regardless of the operator's sitting posture / standing posture.

  Further, if the fluid pressure cylinder is a lock cylinder having a function of locking and unlocking an internal piston at an arbitrary position and constitutes a part of the lock mechanism, the column shaft can be formed as a relatively compact structure. It has a lock mechanism capable of realizing an accurate lock position while making it difficult to obstruct the field of view on the base end side, and makes it easy to perform precise angle adjustment.

  Further, in the tilt type steering unit provided with the lock cylinder, the operation lever has a pedal type operation portion, and the operation by the operation portion is transmitted to the lock cylinder side by sliding of the wire inserted through the tubular body. Then, it becomes possible to perform a delicate operation with the same touch as the brake operation of the vehicle while increasing the degree of freedom of arrangement of the operation lever and the lock cylinder.

  Furthermore, the tilt type steering unit described above connects the operator's steering operation to the steering operation transmission means on the work vehicle side via a universal joint provided on the column shaft base end side, and the base portion is connected to the cab floor. If fixed to the surface and used in common as a steering device for multiple types of work vehicles, the assembly process of the work vehicle can be simplified and the cost can be reduced by using a general-purpose unit. The above-described operation can be easily realized while contributing.

  According to the present invention, the angle of the column shaft can be adjusted by an operation from the ankle to the tip with the heel attached, and the precise angle setting of the column shaft can be easily performed according to various working conditions of the operator. It is.

The side view which shows embodiment of this invention. The side view for demonstrating an effect | action of the steering unit of FIG. The side view for demonstrating an effect | action of the steering unit of FIG. The front view for demonstrating an effect | action of the steering unit of FIG. The side view which shows a prior art example. The side view which shows a prior art example. The front view of the steering unit of FIG.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a side view of a steering unit 1A according to the present embodiment. The steering unit 1A is a unit that is fixedly installed on the floor of a driver's seat of a wheeled work vehicle such as a hydraulic excavator, and can be used in common with a plurality of types of work vehicles. It is provided as a general-purpose steering unit that constitutes a steering device for a vehicle simply by fixing and mounting.

  Further, the steering unit 1A is provided with an annular handle 11 on the front end side, and the column shaft 10 that transmits a steering operation by turning around the axis rotates the front end side in a predetermined range in the front-rear direction ( It is also a tilt type steering unit that can be turned) and can be fixed by adjusting the standing angle with respect to the floor surface X to an angle desired by the operator.

  The column shaft 10 is inserted into a shaft pipe 15 made of steel pipe so as to be rotatable in the circumferential direction, and a pin 14a is provided on the base portion 14 side via a support pipe 16 in which the base end side of the shaft pipe 15 is inserted. It is pivotally supported, and the distal end side can be freely rotated in the front-rear direction with the base portion 14 fixed to the floor surface X side. Specifically, it is about 60 to 85 degrees with respect to the floor surface X. It stands and leans forward and backward. The circumferential rotation that is the steering operation of the column shaft 10 is transmitted in the vertical direction by the universal joint 13 from the state where the axis is inclined, and is connected to the steering operation transmission means (power steering mechanism portion) of the work vehicle. It is like that.

  The base portion 14 has a plurality of fixing holes (not shown) for removably fixing to the floor mounting position of the work vehicle with bolts and nuts in the flange 14b on the bottom side. Further, a lock cylinder 12a is installed between the lower rear surface of the base portion 14 and the lower rear surface of the intermediate portion of the shaft pipe 15. In this installation, the proximal end side of the lock cylinder 12a protrudes from the side surface of the shaft pipe 15. It is pivotally attached to the bracket 15c, and the piston rod 121 on the tip side is pivotally attached to the bracket 14c protruding from the side surface of the base portion 14.

  In the lock cylinder 12a, gas is filled in a pressure chamber formed between a front end surface of a piston (not shown) and a cylinder inner surface on the front end side, and the sliding of the piston is normally locked by a lock means. It becomes a state. Then, by depressing the pedal 122 which is the operation portion of the operation lever 12b, the lock is released by the pulling operation of the wire member 12c connected to the lock means by the wire inserted through the tube, and the piston is generated by the elastic repulsive force of the gas. The rod 121 is biased so as to protrude downward, and the front end side of the column shaft 10 inserted into the shaft pipe 15 is also rotatable and biased in the standing direction.

  Next, the operation of the steering unit 1A will be described in detail with reference to FIGS.

  FIG. 2 is a side view for explaining a case where the operator A adjusts the angle of the steering unit 1 </ b> A while sitting on the seat 50. For example, when the angle of the column shaft 10 of the steering unit 1A falls too far toward the operator A and the handle 11 is too close, the operator A grips the handle 11 with his hand and steps on the pedal 122 of the operation lever 12b with the toe of the right foot. In this case, the height and the operation angle of the pedal 122 from the floor surface X are configured such that the operator A can operate with the heels of the feet attached, so that the operation can be performed only by the movement from the ankle to the tip. It has become.

  By depressing the pedal 122, the wire base end side of the wire member 12c connected to the pedal 122 on the diagonal side is pulled up based on the lever principle, and the wire inserted through the tubular body slides and the lock cylinder 12a The tip side connected to the locking means is pulled, the locked state is released and the internal piston becomes slidable, and the piston rod 121 is urged to protrude downward by the elastic repulsive force of gas.

  Then, the shaft pipe 15 pivotally attached to the side surface of the intermediate portion on the base end side of the lock cylinder 12a is released from the fixed state, and the distal end side is rotatable back and forth, and is urged in the standing direction, and is inserted into the column shaft. 10 is also in a state in which the tip side is pivotable back and forth and is urged in the standing direction. Therefore, the operator A can adjust the angle while moving the handle 11 to a desired position even with one hand, and can continue other operations with the remaining hands, while keeping the back on the seat 50. It is possible to operate with an easy posture.

  Then, the operator A releases the depression of the operation lever 12b when the column shaft 10 has an angle just right for him. Then, the pulling force by the wire member 12c to the lock cylinder 12a is released, and the lock shaft is again locked to fix the standing angle of the column shaft 10.

  The column shaft 10 automatically moves slowly in the standing direction by the above-described unlocking operation. When the standing shaft angle is fixed, a precise angle is operated while operating with a delicate touch similar to the brake operation of the vehicle. Setting can be performed in a relatively short time. That is, since the pedal 122 is operated only by the forward movement from the ankle attached with the heel to the floor surface X, a fine adjustment can be performed.

  In addition, even when the handle 11 gets in the way when the operator A gets out of the driver's seat from this sitting position or operates other operation levers, if the column shaft 10 is similarly fixedly released, Since a large space can be created in front of the operator A by automatically standing up to the maximum angle with respect to the floor surface X, it is easy to get on and off and work.

  Referring to FIG. 3 for explaining the case where the operator A adjusts the angle of the steering wheel in the standing posture, the pedal 122 of the steering unit 1A can be operated on the toe side with the foot of the foot attached even in this posture. And the operating angle. In this case, the merit of the operation from the ankle to the tip becomes more remarkable than the case shown in FIG. That is, it is not necessary to lift the foot into the air and become unstable on one foot, and fine adjustment can be easily performed.

  FIG. 4 shows a front view of the steering unit 1A as viewed from the operator side. As can be seen from the figure, the shaft pipe 15 inserted through the column shaft 10 from the bottom of the handle 11 to the base part 14 has almost no protrusion, and the lock mechanism 12 is compact on the base part 14 side. Compared with the conventional steering units 1B and 1C of FIGS. 5 to 7 described above, the field of view on the lower front side is hardly obstructed.

  As described above, with respect to the steering unit of a work vehicle having a tilt function in the front-rear direction, the present invention makes it possible to easily set the precise angle of the column shaft corresponding to the various work conditions of the operator. It was.

  1A Steering unit, 10 Column shaft, 11 Handle, 12 Lock mechanism, 12a Lock cylinder, 12b Operation lever, 12c Wire member, 14 Base part, 121 Piston rod, 122 Pedal

Claims (4)

A base part fixed to the floor of the cab of the work vehicle is provided, and a base end side is supported by the base part in a state in which a column shaft having a handle is rotatable in a predetermined range in the front-rear direction, A fluid pressure cylinder that exerts an urging force in the protruding direction of the piston rod is installed between the base part and the intermediate part of the column shaft, and the standing angle of the column shaft with respect to the floor surface is fixed at an arbitrary angle. The lock mechanism is provided at a predetermined position, and when the operator depresses the operation lever of the lock mechanism, the lock is released, and the column shaft is urged in the upright direction so that the front end side can be freely rotated. In the tilt type steering unit in which the standing angle is locked by returning
The operation lever is attached to the base portion side, and the operation portion of the operation lever is a height from the floor surface that can be operated by a forward movement from the ankle while an operator keeps a footpad on the floor surface. Tilt-type steering unit characterized by that.   2. The fluid pressure cylinder according to claim 1, wherein the fluid pressure cylinder is a lock cylinder having a function of locking and unlocking an internal piston at an arbitrary position, and constitutes a part of the lock mechanism. Tilted steering unit.   3. The operation lever according to claim 2, wherein the operation lever has a pedal-type operation unit, and an operation by the operation unit is transmitted to the lock cylinder side by sliding of a wire inserted through a tubular body. Tilted steering unit.   The tilt type steering unit according to claim 1, 2 or 3 connects the steering operation of the operator to the steering operation transmission means on the work vehicle side through a universal joint provided on the column shaft base end side. A tilt type steering unit that is used in common as a steering device for a plurality of types of work vehicles by fixing and attaching the base portion to a floor surface of a cab.

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