JPH08301015A - Movable raising-lowering ladder device - Google Patents

Abstract

PURPOSE: To incline a ladder so as to be easily raised and lowered from a cab by arranging an actuating part in a ladder main body, and displacing it to a working position obliquely inclining outward and downward and a housing position becoming vertical along a car body. CONSTITUTION: A bracket 16 is fixed to the upper end of a ladder main body 13, and this bracket 16 is rotatably and pivotally fixed to a bracket 17 having a pin hole fixed to the reverse side on the projecting end of a fender 12 through a pin 10. A bracket 18 in which a pin hole is bored is also fixed to the reverse side of the uppermost stage step 13a of the ladder main body 13, and the tip of a rod 14a of a hydraulic cylinder 14 is pivotally fixed by a pin 19 through the pin hole of this bracket 18. The rod 14a of its hydraulic cylinder 14 is elongated, and the ladder main body is displaced to a housing position, and its rod 14a is reduced, and the ladder main body 13 is displaced to a working position. Therefore, the ladder main body 13 can be inclined so as to be easily raised and lowered from a cab 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel loader and other articulated vehicles and other vehicles, and a movable lifting and lowering ladder device in which a cabin lifting and lowering ladder is mounted between front and rear wheels.

[0002]

2. Description of the Related Art Most of conventional ladders for raising and lowering articulated vehicles such as wheel loaders have a frame for mounting a rudder body 1 on a main frame 3 of a vehicle below a side of a cab 2 as shown in FIGS. It is fixed via 4 and is fixed in a state of being lowered almost vertically from the fender 5.

[0003]

However, this conventional fixed ladder for raising and lowering the earthmoving vehicle is installed in a small space between the front and rear tires 6 and 7 in relation to the position of the cab. , The step width is narrow, and it can not be tilted to prevent it from protruding outside the vehicle,
It was almost vertical and had the drawback of being difficult to move up and down. On the other hand, when the vehicle is running, there is a problem in that it cannot be stored compactly, and thus it is easy to come into contact with an external obstacle. Therefore, it is an object of the present invention to provide a movable lifting ladder device in which the ladder can be tilted so that it can be easily lifted up and down from the cab, and stored during traveling to avoid contact with an external obstacle. To do.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides means for making a lifting ladder movable so that it can be folded and stored below a vehicle fender. It is characterized by trying to solve the problem. That is, the invention of claim 1 is an articulated vehicle in which a frame having a front wheel and a frame having a rear wheel are flexibly connected to each other, and in a ladder device in which a ladder for raising and lowering a cabin is attached between the front wheel and the rear wheel. , The ladder main body is displaceably attached to a use position inclined downwardly and outwardly and a storage position substantially vertical along the vehicle body, and the ladder main body is displaced to the use position or the storage position. The technical means is to provide an operating part. The invention of claim 2 is not limited to an articulated vehicle, but is a vehicle having the above-mentioned ladder device, in which the actuating portion is actuated by starting the engine of the vehicle to displace the rudder main body to the retracted position, and by stopping the engine. The technical means of providing an operating portion control means for activating the operating portion to displace the ladder main body to the use position is taken.

It is preferable that the operating portion control means is provided with a manual switch for displacing the ladder main body to a use position during engine startup. Further, an alarm device may be provided which detects an alarm when the parking brake of the vehicle is released with the manual switch being operated and the ladder main body being in the use position and generating an alarm.

[0006]

According to this movable lifting / lowering ladder device, the operating portion is actuated so that the ladder main body is slanted downward to the use position and the storage position is substantially vertical along the vehicle body. It is possible to displace it, which makes it easy to move up and down from the cab in the use position, and since the ladder body does not project outward in the storage position, it is possible to effectively prevent contact with external obstacles. In addition, by providing the operating part control means, the operating part is controlled in conjunction with the engine start of the vehicle to displace the ladder main body to the storage position, and the operating part is controlled in conjunction with the engine stop to use the ladder main body. It can be displaced into position. If the user wants to use the ladder even while the engine is being started, a manual switch can be provided to control the operating unit so that the ladder body is in the use position. Further, in the case where the manual switch is provided, if the parking brake is released while the switch is still being operated, an alarm is issued from the alarm device to inform the operator that the ladder body is at the use position. You can

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the movable lifting ladder device of the present invention is applied to a wheel loader will be described below with reference to the drawings. Here, the wheel loader is shown as an example of a known articulated vehicle in which a frame having front wheels and a frame having rear wheels are flexibly connected.

FIGS. 1 to 4 show a movable lifting / lowering ladder device of a wheel loader according to this embodiment. The movable lifting / lowering ladder device is a lifting / lowering position portion from a cab 11 of a vehicle body. A rudder main body 13 rotatably pivoted to the lower part of the fender 12 and an actuating part having a base end pivotally pivoted to the lower part of the fender 12 and a tip end fixed to an intermediate part of the rudder main body 13. The hydraulic cylinder 14 is shown as an example, and the operating unit control means 15 (see FIG. 5) having an electric circuit configuration for controlling the expansion / contraction operation of the hydraulic cylinder 14 is provided.

In the case of this embodiment, the ladder main body 13 is made of a ladder having three steps, and a bracket 16 having a pin hole is fixed to the upper end of the ladder main body 13, and this bracket 16 is attached to the fender 12. Is rotatably pivoted through a pin 10 to a bracket 17 with a pin hole fixed to the back side of the projecting end. A bracket 18 having pin holes is also fixed to the back side of the uppermost step 13a of the ladder main body 13, and the tip of the rod 14a of the hydraulic cylinder 14 is pin 19 through the pin hole of the bracket 18. Is pivoted through. The base end of the hydraulic cylinder 14 on the side opposite to the rod 14a portion is the fender 1
It is pivotally attached via a pin 21 to a bracket 20 with a pin hole that is fixed to the lower surface of the vehicle frame 2 side.

In the hydraulic cylinder 14, as shown in FIG.
The coil spring 2 is provided inside the hollow cylinder body 14b.
2 is built in, and always urges the rod 14a in a direction to push it outward. That is, the rod 14a
The coil spring 22 is housed in a compressed state between the base end portion 14c and the inner wall base end portion of the cylinder body 14b.

A small pump 24, which is driven by an engine E of the vehicle, is connected to the hydraulic cylinder 14 via an electromagnetic valve 23, and a hydraulic pressure is applied between the tip of the inner wall of the cylinder body 14b and the base end 14c of the rod 14a. This is what happens. Further, the solenoid valve 23 in the illustrated example is normally biased to the illustrated free position, and has a structure in which it is switched to an operating position for supplying pressure oil in a direction of contracting the hydraulic cylinder 14 by excitation. Reference numeral 30 in the drawing denotes a main pump that is driven by the engine E together with the small pump 24, and is a main circuit S of the hydraulic system of the wheel loader.
Is supplying pressure oil to.

Therefore, when the engine E is stopped, the solenoid valve 23 is in the free position and the hydraulic pressure by the small pump 24 is not applied, so that the base end portion 14c of the rod 14a is moved to the cylinder by the urging force of the coil spring 22. The rod 1 is pushed toward the tip of the inner wall of the body 14b.
The main portion 4a is pushed out from the tip of the cylinder body 14b, and as a result, the ladder body 13 is displaced to the use position in which the ladder body 13 is obliquely lowered and inclined outward.

On the other hand, the starter switch 25 is the solenoid valve 23.
The starter switch 25 is turned on to supply power to the solenoid valve 23. Therefore, when the engine E is started by turning on the starter switch 25, the electromagnetic valve 23 is excited and switched to the operating position in conjunction with this, and pressure oil from the small pump 24 is added to the inside of the cylinder body 14b.

As a result, the coil spring 22 is pushed and contracted, the rod 14a is drawn into the cylinder body 14b, and the fender 12 is folded with the ladder body folded.
It is designed to be stored underneath. Accordingly, when the engine of the vehicle is started, the hydraulic cylinder 14 is extended to displace the ladder main body 13 to the storage position, and when the engine is stopped, the hydraulic cylinder 14 is contracted to displace the ladder main body 13 to the use position.

In the actuating unit control means 15, the starter switch 25 may be directly connected to the solenoid valve 23, but in this embodiment, two toggle switches 27 and 28 are further connected to the starter switch 25 and the solenoid valve 23. It is provided between. One of the two toggle switches 27 and 28 is installed inside the cab, and the other is installed at a position accessible from the ground. When at least one of the toggle switches 27 and 28 is turned off, the starter switch 2
Even when 5 is turned on, power is not supplied to the solenoid valve 23,
The solenoid valve 23 remains in the free position, the hydraulic cylinder 14 remains extended, and the ladder body 13 is held in the use position.

Further, in this embodiment, the OFF terminal sides of the two toggle switches 27 and 28 are electrically connected to the alarm device 29 via the limit switch 26. The limit switch 26 is attached to a release lever (not shown) of the parking brake, and the alarm device 29 is attached inside the cab.

Therefore, when the parking brake is released while either of the toggle switches 27 and 28 is off, the limit switch is turned on, and the parking brake is released while the ladder body 13 is not housed. Alarm device 2 indicates that
It is caused by 9.

The operation of the lifting ladder device having the above structure will be described. When the engine E is stopped, the main portion of the rod 14a is pushed outward by the elastic force of the hydraulic cylinder 14, and the ladder main body is displaced and held at the use position. In this case, for example, the rod 14
By making the length of a appropriately long, the ladder main body 13
Can be tilted and fixed to the outside of the vehicle at an appropriate angle so that it can be easily moved up and down.

Next, when the engine E is started by the starter switch 25, the solenoid valve 23 is switched, and the main portion of the rod 14a is pulled into the cylinder body 14b by the pressure oil from the small pump 24, and the ladder body is folded. It is put in a closed state and stored under the fender 12. When it is desired to get on and off while the engine E is still running, the solenoid valve 23 is switched by turning off one of the two toggle switches 27 and 28, and the small pump 24
The hydraulic pressure from is released, and as a result, the coil spring 2
The rod 14a is extended by the elastic force of 2 and the ladder main body 13
Is returned to the up and down position.

Forgetting to turn off either one of the toggle switches 27 or 28, when the parking brake release lever is moved in order to start the vehicle with the ladder main body 3 in the up / down position, the limit switch 26 The alarm device 29 provided in the cab generates an alarm as a result.
Notify that the ladder body 3 is still in the up / down position.

In the above embodiment, the structure in which the hydraulic cylinder is used as the actuating portion to tilt the ladder main body has been described, but the structure may be such that a guide rail is provided and the ladder main body is slid and inclined. Alternatively, a configuration may be employed in which a ladder main body that is inclined is provided in advance, and the ladder main body is moved in parallel to the use position and returned to the storage position. For displacement (reciprocating movement) of the ladder body, a fluid pressure cylinder, a motor-driven link, or other known reciprocating device can be used. Further, it goes without saying that the circuit for controlling the operating unit is not limited to the above-mentioned embodiment.

[0022]

According to the movable lifting / lowering ladder device of the present invention, the ladder main body can be tilted to be lifted and placed outside the vehicle, or can be stored inside the fender of the vehicle. As a result, it is possible to easily move up and down from the cab, and it is possible to prevent contact with external obstacles during traveling as much as possible. Furthermore, by interlocking the movement of the ladder main body to the folded storage position with the start of the engine, it is possible to avoid the trouble that the vehicle runs with the ladder main body protruding outward. In this way, by folding the ladder body so that it can be stored, the step width of the ladder body can be widened, especially in articulated vehicles, and the height of the first step of the ladder body can be set lower than the conventional one. By doing so, it is possible to make the inclination of the ladder main body in the ascending / descending position gentle.

[Brief description of drawings]

FIG. 1 is a side view of a movable lifting / lowering ladder device according to an embodiment of the present invention.

FIG. 2 shows a movable lifting ladder device in FIG.
It is the front view seen from the (a) line.

FIG. 3 shows a movable lifting ladder device in FIG.
(B) It is the rear view seen from the line direction.

FIG. 4 is a perspective view of a movable lifting ladder device.

FIG. 5 is a circuit diagram showing an example of operation control means for a hydraulic cylinder.

FIG. 6 is a plan view for explaining a conventional ladder device for raising and lowering an earthmoving vehicle.

FIG. 7 is a perspective view of a conventional ladder device for raising and lowering an earthmoving vehicle.

[Explanation of symbols]

 11 ... Cab 12 ... Fender 13 ... Ladder main body 14 ... Hydraulic cylinder 14a ... Rod 14b ... Cylinder main body 14c ... Base end 15 ... Actuator control means 16 ... Bracket 17 ... Bracket with pin hole 18 ... Bracket 19 ... Pin 20 ... Pin Bracket with hole 21 ... Pin 22 ... Coil spring 23 ... Solenoid valve 24 ... Small pump 25 ... Starter switch 26 ... Limit switch 27, 28 ... Toggle switch 29 ... Alarm

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masato Fujita Inventor Masato Fujita 4-10-1 Yoga, Setagaya-ku, Tokyo Inside New Caterpillar Mitsubishi Corp. (72) Inventor Shuji Yoshimura 4-10-1 Yoga, Setagaya-ku, Tokyo Inside New Caterpillar Mitsubishi Corporation

Claims (4)

[Claims] 1. A ladder device comprising a ladder for raising and lowering a cabin between a front wheel and a rear wheel of a vehicle, wherein the vehicle is an articulated vehicle in which a frame having a front wheel and a frame having a rear wheel are flexibly connected. The ladder main body is displaceably attached to a use position in which the ladder main body obliquely descends outward and a storage position that is substantially vertical along the vehicle body, and the ladder main body is used or stored. A movable lifting and lowering ladder device characterized in that it is provided with an actuating portion for displacing it to a position. 2. A ladder device comprising a ladder for raising and lowering a cabin between a front wheel and a rear wheel of a vehicle, wherein the rudder body has a use position in which the ladder main body descends obliquely toward the outside, and a rudder main body is substantially along the vehicle body. It is displaceably attached to a vertical storage position and is provided with an operating portion for displacing the ladder main body to a use position or a storage position. A movable lifting / lowering ladder device, characterized in that it is provided with an operating part control means for displacing and activating the operating part by stopping the engine to displace the ladder main body to a use position. 3. The movable lifting / lowering ladder apparatus according to claim 2, wherein the operating section control means has a manual switch for returning the ladder main body to a use position during engine startup. 4. An alarm device is provided, which detects when the parking brake of the vehicle is released while the ladder main body is in the use position by operating the manual switch and generates an alarm. The movable lifting ladder device according to claim 3.