JP2020168119A - Wheelchair - Google Patents

Abstract

To provide a wheelchair capable of speeding up the motion of a hydraulic cylinder installed in the wheelchair and capable of taking measures to meet inability of a power unit.SOLUTION: The wheelchair includes: main stairs pivotally installed in a bodywork; sub-stairs that are freely slidable along the main stairs; an auxiliary step pivotally installed in the sub stairs; a tilt cylinder 6 that makes the main stairs undulate; a slide drive cylinder 11 that drives the sub-stairs in a direction projecting from the main stairs; a rotary drive cylinder 36 that rotates the auxiliary stairs; power units 51A, 51B that become a hydraulic fluid supply source; and hydraulic circuits 60A, 60B that selectively supply the hydraulic fluid from the power units to any one of the tilt cylinder, slide drive cylinder, and a rotary drive cylinder. To the hydraulic circuits, accumulators 70A,70B are connected and, there is a structure that can supply the hydraulic fluid from the accumulators selectively to any one of the tilt cylinder, slide drive cylinder, and the rotary drive cylinder.SELECTED DRAWING: Figure 5

Description

The present invention relates to a ladder vehicle equipped with a ladder in a vehicle, and more particularly to a ladder vehicle suitable for sending personnel to an aircraft, a low-rise building, or the like, and for rescue or evacuation.

Traditionally, ladder vehicles with telescopic ladders have been used for firefighting activities, rescue, etc. Examples of this type of ladder vehicle include the following Patent Document 1 and the following Patent Document 2 proposed by the applicant.

Japanese Unexamined Patent Publication No. 2003-310779 JP-A-2017-209234

By the way, there is a ladder wheel having a structure in which an auxiliary step is provided on the tip side of a multi-stage ladder that expands and contracts by a sliding operation. In this case, a tilt cylinder that undulates the multi-stage ladder with respect to the upper side of the vehicle body, a slide drive cylinder that expands and contracts the multi-stage ladder by sliding operation, and rotation for horizontally deploying and storing the auxiliary step. The drive cylinders are configured to be driven by a power unit, but recently, in an emergency situation, when it is desired to drive those cylinders quickly, or measures against inoperability due to a failure of the power unit are required.

The present invention has been made in recognition of such a situation, and an object of the present invention is to provide a ladder vehicle capable of speeding up the operation of a hydraulic cylinder provided in a ladder vehicle and taking measures against inoperability of a power unit. ..

One aspect of the present invention is a ladder wheel. This ladder car has a main ladder whose ends are freely undulating on the car body.
A sub-ladder that is slidably attached along the main ladder and can project toward the tip of the main ladder,
An auxiliary step pivotally attached to the tip of the secondary ladder,
A tilt cylinder that raises and lowers the main ladder with respect to the vehicle body,
A slide drive cylinder that drives the sub-ladder in a direction protruding from the main ladder,
A rotation drive cylinder that rotates the auxiliary step,
The power unit that serves as the hydraulic oil supply source and
A hydraulic circuit that selectively supplies hydraulic oil from the power unit to any of the tilt cylinder, the slide drive cylinder, and the rotation drive cylinder is provided.
An accumulator that stores hydraulic oil at a predetermined accumulator is connected to the hydraulic circuit, and hydraulic oil from the accumulator can be selectively supplied to any of the tilt cylinder, the slide drive cylinder, and the rotation drive cylinder. It is characterized by that.

It is preferable to supply one or both of the hydraulic oil from the power unit and the hydraulic oil stored in the accumulator to the hydraulic circuit.

There are a plurality of sets of the main ladder, the sub-ladder, and the auxiliary step, and the tilt cylinder, the slide drive cylinder, the rotation drive cylinder, the power unit, the hydraulic circuit, and the accumulator are provided corresponding to each set. It is good to have.

When one set of power units becomes inoperable, hydraulic oil may be supplied from the other set of power units or accumulators.

It should be noted that any combination of the above components and a conversion of the expression of the present invention between methods, systems and the like are also effective as aspects of the present invention.

According to the ladder wheel according to the present invention, by adding an accumulator to a hydraulic circuit that selectively sends hydraulic oil from a power unit to any of a plurality of hydraulic cylinders, the operation of each hydraulic cylinder can be speeded up. It is possible to drive each hydraulic cylinder when the power unit cannot operate, which in turn improves reliability.

A side view of an embodiment of a ladder vehicle according to the present invention, in which a state when the ladder is not used is shown by a solid line J and a state when the ladder is used is shown by a solid line K. In the embodiment, a plan view showing a developed state of an auxiliary step. In the embodiment, an enlarged side view showing an auxiliary step and a rotation drive mechanism for rotating the auxiliary step. The same enlarged plan view. The hydraulic circuit diagram for operating each hydraulic cylinder in embodiment. The front view which shows an example of the remote control switch for instructing the operation of each hydraulic cylinder in an embodiment. The procedure for using the ladder wheel shown in the embodiment, (A) is the horizontal deployment operation of the auxiliary step, (B) is the state after the auxiliary step is deployed, and (C) is the state where all the handrails are erected. (D) is an explanatory diagram showing a tilt (elevation) operation of the main ladder, (E) a slide extension operation of the secondary ladder, and (F) an explanatory view showing an expansion operation of the auxiliary step to an arbitrary position. The storage procedure for enabling the ladder vehicle to travel as shown in the embodiment, (A) is a rotation operation to a parallel position of the auxiliary step, (B) is a slide contraction operation of the auxiliary ladder, and (C) is. The operation of lowering the main ladder horizontally, (D) is the horizontal retracted state of the main ladder, (E) is the state in which all the handrails are tilted down, (F) is the rotation and retracting operation of the auxiliary step, and (G) is. Explanatory drawing which shows each runnable state in which the main ladder, the secondary ladder, and the auxiliary step are stored.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, processes, etc. shown in the drawings are designated by the same reference numerals, and redundant description will be omitted as appropriate. Moreover, the embodiment is not limited to the invention but is an example, and all the features and combinations thereof described in the embodiment are not necessarily essential to the invention.

In FIGS. 1 to 4, the vehicle 1 has a rectangular parallelepiped frame-shaped vehicle body frame 2, and the end portions of a pair (s) of main ladders 3 are pivotally attached to the upper side portions 2a of the vehicle body frame 2 by pins 4. (Attachable to rotate). The height of the upper side portion 2a of the vehicle body frame 2 is higher than that of the cabin 5 having the driver's seat. A tilt cylinder 6 is provided between the main ladder 3 and the lower part of the vehicle body frame 2. That is, the main body 6a of the tilt cylinder 6 is pivotally attached to the lower part of the vehicle body frame 2 by a pin 7, and the tip of the piston rod 6b of the tilt cylinder 6 is pivotally attached to the main ladder 3 by a pin 8. The tilt cylinder 6 drives the main ladder 3 from the state of the solid line J in FIG. 1 parallel to the upper side portion 2a to a state in which the main ladder 3 is raised at a predetermined angle, and when the tilt cylinder 6 is contracted, the main ladder 3 and the main ladder 3 are driven. The upper side portion 2a becomes parallel, and when extended, the main ladder 3 rotates around the pin 4 as a fulcrum, and rises at a predetermined angle α with respect to the upper side portion 2a as shown by the solid line K in FIG. A staircase 9 is fixed to the vehicle body frame 2 for raising and lowering between the lower portion and the upper side portion 2a of the vehicle body frame 2.

A sub-ladder 10 is slidably provided in parallel on each main ladder 3. A slide drive cylinder 11 is provided between the main ladder 3 and the sub ladder 10. That is, the main body 11a of the slide drive cylinder 11 is pivotally attached to the main ladder 3 with a pin, and the tip of the piston rod 11b of the slide drive cylinder 11 is pivotally attached to the rear end of the auxiliary ladder 10 with a pin. The sub-ladder 10 is supported by a roller (not shown) provided on the main ladder 3 so as to smoothly slide inside the main ladder 3. When the slide drive cylinder 11 is contracted, the sub-ladder 10 is supported by the main ladder 3. When the slide drive cylinder 11 is extended, it protrudes (extends) toward the tip end side of the main ladder 3 as shown by the solid line K in FIG. Handrails 3a and 10a are provided so as to be undulating at positions along the side surface side of the vehicle 1 of the main ladder 3 and the sub ladder 10.

As shown in FIGS. 3 and 4, the auxiliary step 20 is rotatably connected to the tip of each sub-ladder 10. That is, the bracket 21 is fixed to the tip end portion (tip surface) of the auxiliary ladder 10, while the mounting small arm 22 as a mounting member is fixed to the rear end portion of the auxiliary step 20, and the bracket 21 and the mounting small arm 22 both are attached. It is connected by a connecting pin 23 that penetrates. The connecting pin 23 is a pivot that is fixed to the mounting small arm 22, is rotatable with respect to the bracket 21, and rotates integrally with the auxiliary step 20. As shown in FIG. 1, handrails 20a are provided at positions along the side surface side of the vehicle 1 in the auxiliary step 20 so as to be undulating.

The rotation drive mechanism 30 is a chain stretched between a rotation drive sprocket 31 fixed to a connecting pin 23 that rotates integrally with the auxiliary step 20 and a driven sprocket 32, 33, 34 provided on the auxiliary ladder 10. It has a 35 and a rotation drive cylinder 36 for moving the chain 35. The rotary drive cylinder 36 is provided on the lower side of the auxiliary ladder 10. In the rotary drive cylinder 36, the piston rod 36a, which serves as the drive rod, penetrates the main body 36b and projects to both sides of the main body 36b. Then, one end of the chain 35 is connected to one end of the piston rod 36a via the length adjusting metal fitting 37, and the other end of the chain 35 is connected to the other end of the piston rod 36a. The length adjusting metal fitting 37 is adjustable so as to eliminate the slack of the chain 35 and to obtain the optimum tension of the chain 35.

The auxiliary step 20 is in a posture of overlapping on the secondary ladder 10 in an inverted state as shown in FIG. 3 virtual line U as the piston rod (drive rod) 36a of the rotation drive cylinder 36 in the rotation drive mechanism 30 moves. Includes the posture in which the auxiliary step 20 is deployed horizontally as shown by the solid line V in FIG. 3, and the range in which the auxiliary step 20 can be horizontal even if the main ladder 3 is tilted as shown in the solid line K in FIG. It is driven to rotate so as to. At this time, since the rotation amount of the rotation drive sprocket 31 is directly proportional to the movement amount of the piston rod 36a, the unfolding operation of the auxiliary step 20 can be executed extremely smoothly.

The tip ladder 40 can be manually attached to the tip of the auxiliary step 20 as needed. Further, a plate-shaped bullet repellent member 48 is provided undulatingly near the mounting base of the main ladder 3.

In the embodiment, one set of the main ladder 3, the sub-ladder 10 and the auxiliary step 20 is provided on the left side (passenger seat side) and the right side (driver's seat side) of the vehicle 1. A tilt cylinder 6, a slide drive cylinder 11, and a pair of rotary drive cylinders 36 are provided corresponding to each set, and the sets of the left and right main ladder 3, the sub ladder 10, and the auxiliary step 20 are independent. You can move. The tilt cylinder 6, the slide drive cylinder 11, and the rotation drive cylinder 36 are double-acting hydraulic cylinders.

As shown in FIG. 5, a left hydraulic device 50A is provided to drive the left set of tilt cylinder 6, slide drive cylinder 11, and rotary drive cylinder 36. The left hydraulic device 50A selectively supplies the hydraulic oil from the left power unit 51A, which is the hydraulic oil supply source, and the hydraulic oil from the left power unit 51A to any of the tilt cylinder 6, the slide drive cylinder 11, and the rotary drive cylinder 36. It has a circuit 60A and a left accumulator 70A. The left accumulator 70A is connected to the hydraulic oil inlet side port P of the left hydraulic circuit 60A (connected to the hydraulic oil discharge side of the pump P1 of the left power unit 51A) and stores the hydraulic oil at a predetermined accumulator.

Similarly, a right hydraulic device 50B is provided to drive the right set of tilt cylinders 6, slide drive cylinders 11, and rotary drive cylinders 36. The right hydraulic device 50B selectively supplies the hydraulic oil from the right power unit 51B, which is the hydraulic oil supply source, and the hydraulic oil from the right power unit 51B to any of the tilt cylinder 6, the slide drive cylinder 11, and the rotary drive cylinder 36. It has a circuit 60B and a right accumulator 70B. The right accumulator 70B is connected to the hydraulic oil inlet side port P of the right hydraulic circuit 60B (connected to the hydraulic oil discharge side of the pump P2 of the right power unit 51B) and stores the hydraulic oil at a predetermined accumulator.

The left power unit 51A has a motor M1 connected to the battery of the vehicle 1 via the main switch S1, a pump P1 rotationally driven by the motor M1, and an oil tank 90 common to the right power unit 51B. When the motor M1 is energized, the pump P1 is rotationally driven by the motor M1 to discharge hydraulic oil to the hydraulic oil inlet side port P of the left hydraulic circuit 60A.

Similarly, the right power unit 51B has a motor M2 connected to the battery of the vehicle 1 via the main switch S2, and a pump P2 rotationally driven by the motor M2. When the motor M2 is energized, the pump P2 is rotationally driven by the motor M2 to discharge the hydraulic oil to the hydraulic oil inlet side port P of the right hydraulic circuit 60B. The hydraulic oil return port T of each of the hydraulic circuits 60A and 60B is connected to a common oil tank 90 with a pipe for returning hydraulic oil.

The left hydraulic circuit 60A has a function of selectively supplying the hydraulic oil from the left power unit 51A to any of the left tilt cylinder 6, the slide drive cylinder 10, and the rotary drive cylinder 36. That is, the left hydraulic circuit 60A expands and contracts the electromagnetic switching valve 81 for switching the vertical drive of the tilt cylinder 6 that rotates the left main ladder 3 and the slide drive cylinder 11 that slides the left auxiliary ladder 10. It has an electromagnetic switching valve 82 for switching and an electromagnetic switching valve 83 for switching the rotation direction of the auxiliary step 20 on the left side. The left accumulator 70A is connected to the hydraulic oil inlet side port P of the left hydraulic circuit 60A via a parallel connection of the check valve and the solenoid valve 72A and a manual on-off valve 73A (usually in the open state). A pressure switch S2A is provided in the hydraulic oil supply pipe to the left accumulator 70A, detects the accumulated pressure of the hydraulic oil of the left accumulator 70A, and stops the energization of the motor M1 when the accumulated pressure reaches a predetermined value.

Similarly, the right hydraulic circuit 60B has a function of selectively supplying the hydraulic oil from the right power unit 51B to any of the right tilt cylinder 6, the slide drive cylinder 10, and the rotary drive cylinder 36. That is, the right hydraulic circuit 60B expands and contracts the electromagnetic switching valve 81 for switching the vertical drive of the tilt cylinder 6 that rotates the right main ladder 3 and the slide drive cylinder 11 that slides the right auxiliary ladder 10. It has an electromagnetic switching valve 82 for switching and an electromagnetic switching valve 83 for switching the rotation direction of the auxiliary step 20 on the right side. The right accumulator 70B is connected to the hydraulic oil inlet side port P of the right hydraulic circuit 60B via a parallel connection of the check valve and the solenoid valve 72B and a manual on-off valve 73B (usually in the open state). A pressure switch S2B is provided in the hydraulic oil supply pipe to the right accumulator 70B, detects the accumulated pressure of the hydraulic oil in the right accumulator 70B, and stops the energization of the motor M2 when the accumulated pressure reaches a predetermined value. The electromagnetic switching valves 81 to 83 are stopped (shut off) in the non-excited state and maintain the immediately preceding state. The solenoid valves 72A and 72B are shut off in the non-excited state and do not supply hydraulic oil to the left and right hydraulic circuits 60A and 60B (the hydraulic oil can be supplied from the pump via the check valve).

The left hydraulic circuit 60A and the right hydraulic circuit 60B are connected by a manual on-off valve 75. The manual on-off valve 75 is normally closed, but when either the left hydraulic device 50A or the right hydraulic device 50B becomes inoperable, the manual on-off valve 75 is opened so that the other device can drive the valve 75. ing.

FIG. 6 is an example of the push button arrangement of the remote control switch 100 with a cord (the cord is not shown). On the left side (passenger seat side), the power lamp L1 of the left hydraulic device 50A and the deployment instruction of the auxiliary step 20 are in order from the top. Supplementary button B1L for auxiliary step 20, auxiliary button B2L for storage instruction of auxiliary step 20, extension button B3L for extension instruction of sub-ladder 10, contraction button B4L for contraction instruction of sub-ladder 10, main The main upper button B5L for ascending instruction of the ladder 3 and the main lower button B6L for ascending instruction of the main ladder 3 are arranged. Similarly, on the right side (driver's seat side), in order from the top, the power lamp L2 of the right hydraulic device 50B, the supplement button B1R for the deployment instruction of the auxiliary step 20, and the supplement button for the storage instruction of the auxiliary step 20. B2R, extension button B3R for extension instruction of sub-ladder 10, contraction button B4R for contraction instruction of sub-ladder 10, main upper button B5R for ascent instruction of main bridge 3, lowering of main bridge 3. The main and lower buttons B6R for instructions are arranged. As shown in FIG. 1, the left and right hydraulic devices 50A and 50B controllers 55 are installed in the vehicle body frame 2, and metal outlets 56 for connecting the corded remote controller switch 100 to the controller 55 are located in the front and rear of the vehicle 1. It is located in. The remote control switch 100 with a cord is used in a state of being connected to the metal outlet 56. The accumulators 70A and 70B are installed on the back side of the stairs 9 in the vehicle body frame 2.

FIG. 7 will describe a procedure for driving the main ladder 3, the sub-ladder 10 and the auxiliary step 20 toward an object such as an aircraft or a low-rise building after the ladder vehicle has stopped. In order to enable the operation of the remote control switch 100, the switchboard of the controller 55 in FIG. 1 is operated to turn on the power of the left and right hydraulic devices 50A and 50B, and the power lamps L1 and L2 of the remote control switch 100 are turned on (normally). The left and right hydraulic systems can be operated). As a result, the main switches S1 and S2 of the left and right power units 51A and 51B are turned on, and hydraulic oil is stored in the left and right accumulators 70A and 70B so as to have a predetermined accumulator.

Here, in order to simplify the description, a case will be described in which the pushbutton group on the left side of FIG. 6 is operated to drive the main ladder 3, the sub-ladder 10 and the auxiliary step 20 on the left side. First, when the supplement button B1L is pressed to excite the solenoid 83b of the electromagnetic switching valve 83 of the left hydraulic circuit 60A in FIG. 5, the electromagnetic switching valve 83 is opened and operates from the cylinder connection port B3 through one path of the electromagnetic switching valve 83. The oil is delivered, the piston rod 36a of the rotary drive cylinder 36 moves, and the auxiliary step 20 is expanded to the horizontal position as shown in FIG. 7 (A) (the supplement button B1L is released at the horizontal position), and FIG. 7 ( Bring to the state of B). From the state of FIG. 7 (B), the state of FIG. 7 (C) in which all the handrails 3a, 10a, and 20a are erected.

Next, when the main upper button B5L of FIG. 6 is pressed to excite the solenoid 81b of the electromagnetic switching valve 81, the electromagnetic switching valve 81 is opened and hydraulic oil is discharged from the cylinder connection port B1 through one path of the electromagnetic switching valve 81. Then, the tilt cylinder 6 is extended to raise the tip of the main ladder 3 as shown in FIG. 7 (D) (release the main upper button B5L at a desired raising position).

After that, when the extension button B3L is pressed to excite the solenoid 82b of the electromagnetic switching valve 82, the electromagnetic switching valve 82 is opened, hydraulic oil is sent from the cylinder connection port B2 through one path of the electromagnetic switching valve 82, and the slide drive cylinder. When 11 is extended, the sub-ladder 10 is extended by a predetermined length as shown in FIG. 7 (E) (the extension button B3L is released at a desired length). Further, the supplement button B1L is pressed to develop the posture of the auxiliary step 20 substantially horizontally as shown in FIG. 7 (F).

As a result, personnel can be sent to the aircraft or building by the route of the stairs 9, the main ladder 3, the sub-ladder 10 and the auxiliary step 20 (and the tip ladder 40 if necessary), or in the reverse route for rescue etc. It is possible to evacuate personnel.

The storage procedure of the main ladder 3, the sub-ladder 10 and the auxiliary step 20 for enabling the vehicle 1 to travel will be described with reference to FIG. First, when the auxiliary button B2L is pressed to excite the solenoid 83a of the electromagnetic switching valve 83 of the left hydraulic circuit 60A in FIG. 5, the electromagnetic switching valve 83 is opened and operates from the cylinder connection port A3 through the other path of the electromagnetic switching valve 83. Oil is delivered, and the piston rod 36a of the rotary drive cylinder 36 moves in the opposite direction to position the auxiliary step 20 parallel to the sub-ladder 10 as shown in FIG. 8A (the auxiliary button B2L is pressed at the parallel position). (Release) to the state shown in FIG. 8 (B).

Next, when the contraction button B4L is pressed to excite the solenoid 82a of the electromagnetic switching valve 82, the electromagnetic switching valve 82 is opened, hydraulic oil is sent from the cylinder connection port A2 through the other path of the electromagnetic switching valve 82, and slide drive is performed. As the cylinder 11 contracts, it is stored up to a position where the sub-ladder 10 overlaps with the main ladder 3 in which the amount of protrusion is minimized, as shown in FIG. 8C.

Further, when the main lower button B6L of FIG. 6 is pressed from the retracted state of the sub-ladder 10 of FIG. 8C to excite the solenoid 81a of the electromagnetic switching valve 81, the electromagnetic switching valve 81 is opened and the electromagnetic switching valve 81 is opened. Hydraulic oil is delivered from the cylinder connection port A1 through the other path, the tilt cylinder 6 is contracted, and the main ladder 10 is stored parallel to the upper side portion 2a of the vehicle body frame 2 as shown in FIG. 8 (D). Cylinder.

From the state shown in FIG. 8D, all the handrails 3a, 10a, and 20a are tilted to obtain the state shown in FIG. 8E. After that, the auxiliary step B2L is pressed to store the auxiliary step 20 in a state of being overlapped with the main ladder 3 so that the vehicle 1 of FIG. 8 (G) can travel (remove the bollard or the like if necessary).

By operating the pushbutton group on the right side of FIG. 6, the main ladder 3, the sub-ladder 10 and the auxiliary step 20 on the right side can be driven in the same manner.

The drive speeds of the main ladder 3, the sub-ladder 10 and the auxiliary step 20 in FIGS. 7 and 8 are per unit time of the pumps P1 and P2 of the left and right hydraulic devices 50A and 50B when the accumulators 70A and 70B are not used. It is proportional to the amount of hydraulic oil discharged. Therefore, in conjunction with the pressing operation of the push button of the remote control switch 100, that is, by opening the solenoid valves 72A or 72B at the same time that the solenoid switching valves 81 to 83 are opened, the hydraulic oil is also supplied from the accumulator 70A or 70B. Is supplied to the left and right hydraulic circuits 60A or 60B to increase the driving speed of the main ladder 3, the sub-ladder 10 and the auxiliary step 20, and the ladder 3, the sub-ladder 10 and the auxiliary step 20 are deployed to the object, and It is possible to store them quickly.

The accumulators 70A and 70B store hydraulic oil so that at least 1.5 reciprocations can be performed when the operations from FIGS. 7 (A) to 8 (G) are reciprocated. Therefore, when the power units 51A and 51B of the left and right hydraulic devices 50A and 50B become inoperable due to a failure or the like, hydraulic oil is supplied from the accumulators 70A and 70B to the hydraulic devices 50A and 50B to supply the hydraulic oils to the hydraulic devices 50A and 50B. It is possible to perform the operations of FIGS. 7 and 8 of the ladder 10 and the auxiliary step 20.

Further, since the left hydraulic circuit 60A and the right hydraulic circuit 60B are connected by a manual on-off valve 75 (normally closed), the left hydraulic device 50A and the right hydraulic device 50B can be opened by manually opening the manual on-off valve 75. When either one of the power units 51A or 51B becomes inoperable, both hydraulic devices 50A and 50B can be driven by the normally operating power unit.

According to this embodiment, the following effects can be achieved.

(1) A tilt cylinder 6 for raising and lowering the main ladder 3 with respect to the vehicle body frame 2, a slide drive cylinder 11 for driving the sub-ladder 10 in a direction protruding from the main ladder 3, and an auxiliary connected to the tip of the sub-ladder 10. In the configuration having the rotation drive cylinder 36 for rotating the step 20, since the accumulators 70A and 70B are provided in the hydraulic devices 50A and 50B (because the accumulator is added to the hydraulic circuit), the hydraulic oil from the power units 51A and 51B By supplying the hydraulic oil from the accumulators 70A and 70B to the hydraulic circuit in addition to the supply to the hydraulic circuit, it is possible to speed up the operation of the main ladder 3, the sub-ladder 10 and the auxiliary step 20.

(2) When the power units 51A and 51B of the hydraulic devices 50A and 50B become inoperable due to a failure, the tilt cylinder 6, the slide drive cylinder 11 and the rotation drive cylinder 36 are operated by the hydraulic oil stored in the accumulators 70A and 70B. The main ladder 3, the sub-ladder 10, and the auxiliary step 20 can be made to perform the required operation.

(3) For the set of the main ladder 3, the sub-ladder 10 and the auxiliary step 20 on the left side, the left hydraulic device 50A is for the set of the main ladder 3, the sub-ladder 10 and the auxiliary step 20 on the right side. 50B is provided, and when one of the power units 51A and 51B of the hydraulic devices 50A and 50B becomes inoperable, a manual on-off valve 75 that connects the left hydraulic circuit 60A and the right hydraulic circuit 60B. By opening, the hydraulic oil can be supplied to the left and right hydraulic devices 50A and 50B by the power unit that operates normally. Therefore, the main ladder 3, the sub-ladder 10, and the auxiliary step 20 can be made to perform the necessary operations. For example, it is possible to return to a state in which the vehicle can run.

(4) By providing the two hydraulic devices 50A and 50B and the accumulators 70A and 70B, even if the power unit becomes inoperable, the main ladder 3, the sub-ladder 10 and the auxiliary step 20 can be driven and operated. It is possible to improve the reliability of the.

Although the present invention has been described above by taking the embodiment as an example, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, a modification will be described.

In the above embodiment, the main ladder 3 and the sub-ladder 10 may each have a structure having a continuous slope or a structure in which scaffolds are arranged at equal intervals.

The hydraulic circuits included in the hydraulic devices 50A and 50B can be appropriately changed as long as the required object can be achieved. Further, although the case where the hydraulic devices 50A and 50B are operated by the remote controller switch 100 with a cord is illustrated, a cordless remote controller switch can also be adopted.

1 Vehicle 2 Body frame 3 Main ladder 5 Cabin 6 Tilt cylinder 10 Sub ladder 11 Slide drive cylinder 20 Auxiliary step 30 Rotation drive mechanism 31 Rotation drive sprocket 35 Chain 36 Rotation drive cylinder 40 Tip ladder 50A, 50B Hydraulic device 51A , 51B Power unit 60A, 60B Hydraulic circuit 70A, 70B Accumulator 100 Remote control switch with cord

Claims (4)

A main ladder whose ends are undulating freely on the car body,
A sub-ladder that is slidably attached along the main ladder and can project toward the tip of the main ladder,
An auxiliary step pivotally attached to the tip of the secondary ladder,
A tilt cylinder that raises and lowers the main ladder with respect to the vehicle body,
A slide drive cylinder that drives the sub-ladder in a direction protruding from the main ladder,
A rotation drive cylinder that rotates the auxiliary step,
The power unit that serves as the hydraulic oil supply source and
A hydraulic circuit that selectively supplies hydraulic oil from the power unit to any of the tilt cylinder, the slide drive cylinder, and the rotation drive cylinder is provided.
An accumulator that stores hydraulic oil at a predetermined accumulator is connected to the hydraulic circuit, and hydraulic oil from the accumulator can be selectively supplied to any of the tilt cylinder, the slide drive cylinder, and the rotation drive cylinder. , Ladder car. The ladder wheel according to claim 1, wherein one or both of the hydraulic oil from the power unit and the hydraulic oil stored in the accumulator is supplied to the hydraulic circuit. There are a plurality of sets of the main ladder, the sub-ladder, and the auxiliary step.
The ladder wheel according to claim 1 or 2, wherein the tilt cylinder, the slide drive cylinder, the rotation drive cylinder, the power unit, the hydraulic circuit, and the accumulator are provided corresponding to each set. The ladder wheel according to claim 3, wherein when any set of power units becomes inoperable, hydraulic oil is supplied from another set of power units or accumulators.