Ladder / boom mounted vehicle

Abstract

To shorten an overhang time of an outrigger, and to enhance operability and safety in ladder operation, in a ladder / boom-mounted vehicle.SOLUTION: A plurality of outriggers 8 provided on a vehicle body 2, an outrigger cylinder 12 having an extension-side oil chamber 121 and a contraction-side oil chamber 122, an oil tank 13, a hydraulic pump 14, and an outrigger speed-up switching valve 23 are provided, and when an operation of moving one of the outriggers 8 provided on the left side or one of the outriggers 8 provided on the right side to the overhang side is selected, a controller turns off the outrigger speed-up switching valve 23 to set a destination of oil discharged from the contraction-side oil chamber 122 to the oil tank 13. When an operation of simultaneously moving two or more of the outriggers 8 provided on the left side or two or more of the outriggers 8 provided on the right side to the overhang side is selected, the destination of the oil discharged from the contraction-side oil chamber 122 is set to the extension-side oil chamber 121 by turning on the outrigger acceleration switching valve 23.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a ladder / boom-mounted vehicle, such as a fire ladder truck or aerial work vehicle, that is equipped with a ladder or a boom and outriggers. [Background technology]

[0002] In a ladder / boom-equipped vehicle such as a fire ladder truck equipped with a ladder or boom that can be extended, raised, or rotated, the ladder or boom is extended, rotated, raised, and rotated while the outriggers are extended and the vehicle is jacked up. For example, Patent Document 1 discloses an outrigger device for a work machine that has a plurality of outriggers driven by a plurality of slide cylinders and jack cylinders connected to a variable displacement pump via an extension / retraction direction change valve and a control valve, and in which a control unit changes the capacity of the variable displacement pump via a capacity change valve depending on the operation mode. Patent Document 2 also discloses a speed control device for an outrigger jack on a work vehicle, which includes a differential circuit in the hydraulic circuit of the outrigger jack that allows the jack cylinder to be extended at high speed or at normal speed depending on the amount of oil discharged from the jack cylinder retraction side oil chamber when the jack cylinder is extended, a jack reaction force detection means that detects the reaction force of the outrigger jack, and a control means that maintains the differential circuit in a state where the jack cylinder is extended at high speed when the jack reaction force detection means detects a low jack reaction force, and maintains the differential circuit in a state where the jack cylinder is extended at normal speed when the jack reaction force detection means detects a high jack reaction force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-001097 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-156312 Summary of the Invention [Problem to be solved by the invention]

[0004] Firefighting ladder trucks, which are used for firefighting and rescue operations, are particularly in urgent need of assistance, and it is necessary to extend the ladder as quickly as possible after arriving at the disaster site. However, the outriggers, which are extended before the ladder is extended, are hydraulically operated and require a certain amount of time to fully extend, so there is a need to shorten the time it takes for the outriggers to be extended. Furthermore, further improvements in operability and safety when extending the ladder are also important issues. One way to shorten the extension time of the outriggers is to increase the operating speed by increasing the amount of oil and hydraulic pressure, but this is difficult to achieve due to the constraints of the entire device. Furthermore, Patent Document 1 aims to improve operability by keeping the operating speed of the outriggers constant whether multiple outriggers are operated simultaneously or individually, but does not attempt to shorten the time required to complete extension. Furthermore, Patent Document 2 aims to shorten the time required for jacking up in the vertical direction, but does not aim to shorten the time required for extending the outriggers in the vehicle width direction. Therefore, an object of the present invention is to shorten the time it takes for outriggers to be extended in the vehicle width direction in a ladder / boom-equipped vehicle, and to improve operability and safety when operating a ladder. [Means for solving the problem]

[0005] The ladder / boom-equipped vehicle of the present invention described in claim 1 comprises a ladder 3 or boom mounted on the vehicle, a plurality of outriggers 8 provided on each of the left and right sides of the vehicle body 2, an extension-side oil chamber 121 to which oil is supplied when the outriggers 8 are extended, and a retraction-side oil chamber 122 to which oil is supplied when the outriggers 8 are retracted, and further comprises a hydraulic outrigger cylinder 12 used to extend the outriggers 8, an oil tank 13 in which oil to be supplied to the outrigger cylinder 12 is stored, and a hydraulic pump 14 for pressurizing the oil drawn up from the oil tank 13. ,oil Controller that controls the pressure circuit a hydraulic telescopic cylinder 9 used to extend or retract the ladder 3 or boom; a hydraulic derricking cylinder 10 used to raise or lower the ladder 3 or boom; a hydraulic bending cylinder 11 used to bend the bending stage provided at the tip of the ladder 3 or boom; a proportional valve 18 for controlling the amount of oil supplied to the telescopic cylinder 9, the derricking cylinder 10, or the bending cylinder 11; a manual operation lever 19 provided integrally with the proportional valve 18 and connected to an emergency circuit; and a counterbalance valve 26 used to maintain the position of the telescopic cylinder 9, the emergency circuit being provided with an orifice 24 for restricting the flow rate of oil, the telescopic cylinder 9 and the counterbalance valve 26 being connected by a flexible hose, and a check valve 27 provided between the telescopic cylinder 9 and the counterbalance valve 26. It is characterized by: Claim 2The present invention as described is Claim 1 In the ladder / boom-equipped vehicle described in the above, the hydraulic circuit comprises a low-pressure circuit and a high-pressure circuit, and the telescopic cylinder 9, the derricking cylinder 10, and the bending cylinder 11 are supplied with high-pressure oil of 22 MPa or more flowing through the high-pressure circuit, and the outrigger cylinder 12 is supplied with low-pressure oil of less than 22 MPa flowing through the low-pressure circuit, and the manifold block 16 in the high-pressure circuit is made of iron, and the manifold block 17 in the low-pressure circuit is made of aluminum. Claim 3 The present invention as described is Claim 1 or Claim 2 The ladder / boom-equipped vehicle described in the above is equipped with a swing hydraulic motor 15 used to swing the ladder 3 or the boom, and the controller is characterized in that when any one of the ladder 3 hoisting operation, swing operation, and bending operation, or swing operation and bending operation, is selected, the controller sets the rotation speed of the hydraulic pump 14 to a first rotation speed, when any one of the ladder 3 extension / retraction operation, ladder hoisting operation and swing operation, ladder hoisting operation and bending operation, or operation of the outriggers 8 is selected, the controller sets the rotation speed of the hydraulic pump 14 to a second rotation speed higher than the first rotation speed, and when at least one of the ladder hoisting operation, swing operation, bending operation, and operation of the outriggers 8 is selected in addition to the extension / retraction operation, the controller sets the rotation speed of the hydraulic pump 14 to a third rotation speed higher than the second rotation speed. [Effects of the Invention]

[0006] According to the present invention, in a ladder / boom-equipped vehicle, the time required for extending the outriggers can be shortened, allowing for early commencement of operations such as extending and retracting the ladder. In addition, the operability and safety of ladder operation can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 shows a ladder-equipped vehicle according to an embodiment of the present invention. [Figure 2] FIG. 1 shows a schematic configuration of the hydraulic system. [Figure 3] A diagram showing the speed-increasing circuit of the outrigger [Figure 4] Diagram showing the proportional valve circuit and emergency circuit [Figure 5]A diagram showing the circuit of the telescopic cylinder DETAILED DESCRIPTION OF THE INVENTION

[0008] A ladder / boom-equipped vehicle according to a first embodiment of the present invention comprises a ladder or boom mounted on the vehicle, a plurality of outriggers provided on each of the left and right sides of the vehicle body, an extension-side oil chamber to which oil is supplied when the outriggers are extended, and a retraction-side oil chamber to which oil is supplied when the outriggers are retracted, and further comprises hydraulic outrigger cylinders used to extend the outriggers, an oil tank in which oil to be supplied to the outrigger cylinders is stored, and a hydraulic pump that pressurizes the oil drawn up from the oil tank. ,oil Controller that controls the pressure circuit a hydraulic telescopic cylinder used to extend or retract the ladder or boom; a hydraulic derricking cylinder used to raise or lower the ladder or boom; a hydraulic bending cylinder used to bend the bending stage provided at the tip of the ladder or boom; a proportional valve that controls the amount of oil supplied to the telescopic cylinder, the derricking cylinder, or the bending cylinder; a manual operation lever that is provided integrally with the proportional valve and connected to an emergency circuit; and a counterbalance valve that is used to maintain the position of the telescopic cylinder, the emergency circuit being provided with an orifice that throttles the oil flow rate, the telescopic cylinder and the counterbalance valve being connected by a flexible hose, and a check valve being provided between the telescopic cylinder and the counterbalance valve. It is something. According to this embodiment, This saves space compared to installing an emergency operation valve separate from the proportional valve. Furthermore, by using an orifice to restrict the flow rate of the emergency circuit, the ladder speed during manual operation can be suppressed, improving operability and safety. Furthermore, according to this embodiment, the connection is made with a flexible hose, preventing the connection between the telescopic cylinder and the counterbalance valve from being disconnected due to the cylinder's swing. Furthermore, by providing a check valve, the position of the telescopic cylinder can be maintained even if the flexible hose ruptures. Furthermore, by providing a check valve, the operating pressure in the retraction direction can be reduced.

[0009] The present invention No. 2 The embodiment of the present invention is No. 1 In the ladder / boom-equipped vehicle according to the embodiment, the hydraulic circuit comprises a low-pressure circuit and a high-pressure circuit, and the telescopic cylinder, the hoisting cylinder, and the bending cylinder are supplied with high-pressure oil of 22 MPa or more flowing through the high-pressure circuit, and the outrigger cylinders are supplied with low-pressure oil of less than 22 MPa flowing through the low-pressure circuit, and the manifold block in the high-pressure circuit is made of iron, and the manifold block in the low-pressure circuit is made of aluminum. This embodiment allows the diameters of the telescopic cylinder, hoisting cylinder, and articulating cylinder to be reduced while increasing their operating speed. Furthermore, by supplying low-pressure oil to the outriggers whose speeds can be increased using the outrigger speed increase switching valve and constructing the low-pressure circuit manifold block from aluminum, the weight can be reduced.

[0010] The present invention Third The embodiment of the present invention is 1st or 2ndIn the embodiment of the ladder / boom-equipped vehicle, a swing hydraulic motor is provided for swinging the ladder or boom, and the controller sets the rotation speed of the hydraulic pump to a first rotation speed when any one of the ladder hoisting operation, swing operation, and bending operation, or swing operation and bending operation, is selected, sets the rotation speed of the hydraulic pump to a second rotation speed higher than the first rotation speed when any one of the ladder extension / retraction operation, hoisting operation and swing operation, hoisting operation and bending operation, or outrigger operation, is selected, and sets the rotation speed of the hydraulic pump to a third rotation speed higher than the second rotation speed when at least one of the ladder hoisting operation, swing operation, bending operation, and outrigger operation, in addition to the extension / retraction operation, is selected. According to this embodiment, by changing the rotation speed of the hydraulic pump depending on the load, it is possible to save energy and reduce costs compared to when the hydraulic pump is always operated at the maximum rotation speed. [Example]

[0011] The ladder / boom-equipped vehicle according to one embodiment of the present invention will be described below. Note that while this embodiment will be described as a ladder-equipped vehicle equipped with a ladder, the same principle applies to a boom-equipped vehicle equipped with a boom. FIG. 1 shows a ladder-equipped vehicle according to this embodiment, and FIG. 2 shows a schematic configuration of a hydraulic system. As shown in Figure 1, a ladder-equipped vehicle (fire ladder truck) is equipped with a cabin 1 located at the front of the vehicle and having a driver's seat, a vehicle body 2 located behind the cabin 1, a ladder 3 having multiple ladder sections and stored in a prone position above the cabin 1 and vehicle body 2, a gyro turntable 4 located at the rear of the vehicle body 2 and used to correct the inclination of the ladder 3, a support frame 5 located on top of the gyro turntable 4 and supporting the rear end of the ladder 3, a support device 6 located close to the rear of the cabin 1 and supporting the ladder 3 from below, a basket 7 attached to the tip of the ladder 3, and two outriggers 8 provided on each of the left and right sides of the vehicle body 2. The ladder 3 is provided with a hydraulic telescopic cylinder 9 used for extension and retraction, a hydraulic elevation cylinder 10 used for elevation, and a hydraulic bending cylinder 11 used for adjusting the bending angle of the bending step.

[0012] 2, the ladder-equipped vehicle also includes hydraulic outrigger cylinders 12 used to extend the outriggers 8, an oil tank 13 that stores oil to be supplied to the outrigger cylinders 12, a hydraulic pump 14 that pressurizes and discharges oil drawn from the oil tank 13, a swing hydraulic motor 15 used to swing the ladder 3, a high-pressure module 16 that is a manifold block in the high-pressure circuit, a low-pressure module 17 that is a manifold block in the low-pressure circuit, a proportional valve 18 that controls the amount of oil supplied to the telescopic cylinder 9, the hoisting cylinder 10, the bending cylinder 11, and the swing hydraulic motor 15, a manual operation lever 19 attached to the proportional valve 18, an oil cooler 20 installed in the piping through which oil returns to the oil tank 13, and an automatic stop valve 21 that cuts off the supply of oil to each cylinder. Although not shown in the figure, a controller is also provided to control the hydraulic circuit.

[0013] In a ladder-equipped vehicle, one hydraulic system drives both the ladder 3 and the outriggers 8. The hydraulic circuit is provided with a low-pressure circuit and a high-pressure circuit, and high-pressure oil of 22 MPa or more that flows through the high-pressure circuit is supplied to the telescopic cylinder 9, the elevation cylinder 10, and the articulation cylinder 11, while low-pressure oil of less than 22 MPa that flows through the low-pressure circuit is supplied to the outrigger cylinder 12. In addition, the high-pressure module 16 in the high-pressure circuit is made of iron material such as steel, and the low-pressure module 17 in the low-pressure circuit is made of aluminum material such as aluminum alloy. By supplying high-pressure oil to the telescopic cylinder 9, the hoisting cylinder 10, and the articulating cylinder 11, it is possible to increase the operating speed while reducing the diameter of these hydraulic cylinders. Also, aluminum cannot handle high-pressure oil, and if the entire manifold block were made of iron, which can handle high pressure, it would be heavy. Therefore, as described below, by supplying low-pressure oil to the outriggers 8, which can be accelerated by the outrigger acceleration switching valve 23, and by constructing the manifold block of the low-pressure circuit (low-pressure module 17) from aluminum, it is possible to reduce weight.

[0014] In addition, since the amount of heat generated increases when the oil is pressurized, an oil cooler 20 is provided in the middle of the piping through which the oil returns to the oil tank 13. The oil cooler 20 is preferably disposed in a location that is least susceptible to the influence of engine exhaust heat, and is therefore disposed, for example, between the sub-frames and in the vicinity of the front of the gyro turntable 4.

[0015] FIG. 3 is a diagram showing the speed increasing circuit of the outrigger. The outrigger cylinder 12 is of a double-acting type and has an extension-side oil chamber 121 to which oil is supplied when the outrigger 8 is extended, and a retraction-side oil chamber 122 to which oil is supplied when the outrigger 8 is retracted. Relatively low-pressure oil is supplied to the outrigger cylinders 12 via outrigger selector valves 123 provided for each. Oil is also supplied via the outrigger selector valves 123 to the four hydraulic jack cylinders 22 used to jack up the outriggers 8. The outrigger selector valves 123 are also provided with an outrigger manual operation lever 123A for manually extending and retracting the outriggers 8 and operating the jacks when normal operation is not possible due to a malfunction, loss of power, etc. An outrigger acceleration switching valve 23 is provided in each pipe connecting the outrigger cylinder 12 and the outrigger switching valve 123. The outrigger acceleration switching valve 23 is used to switch the destination of oil discharged from the compression-side oil chamber 122 from the oil tank 13 to the extension-side oil chamber 121.

[0016] The controller that controls the hydraulic circuit turns off the outrigger acceleration switching valve 23 when an operation to move one of the two front and rear outriggers 8 provided on the left side of the vehicle or one of the two front and rear outriggers 8 provided on the right side toward the extension side is selected. As a result, oil discharged from the retraction-side oil chamber 122 of the outrigger cylinder 12 is returned to the oil tank 13. On the other hand, when an operation to simultaneously move both of the two front and rear outriggers 8 provided on the left side of the vehicle or both of the two outriggers 8 provided on the right side toward the extension side is selected, the outrigger acceleration switching valve 23 is turned on. As a result, oil discharged from the retraction-side oil chamber 122 of the outrigger cylinder 12 is supplied to the extension-side oil chamber 121 of the outrigger cylinder 12. Note that this control is performed when at least two outriggers on either the left or right side are extended simultaneously, and therefore this control also applies when an operation to simultaneously move all four outriggers 8 toward the extension side is selected. In this way, when extending two or all four outriggers 8 on one side at the same time, the oil discharged from the retraction-side oil chamber 122 of the outrigger cylinder 12 can be sent to the extension-side oil chamber 121 to increase the amount of oil and accelerate the extension speed of the outriggers 8. Also, when moving only one outrigger 8 on one side or one on each side, the oil discharged from the retraction-side oil chamber 122 of the outrigger cylinder 12 is returned to the oil tank 13 to prevent the extension speed from increasing, making it easier to fine-tune the extension amount of the outriggers 8. This shortens the time until the outriggers 8 are fully extended, allowing operations such as extending and retracting the ladder 3 to begin sooner.

[0017] Furthermore, the controller of the hydraulic circuit changes the rotation speed of the hydraulic pump 14 in response to the operation of the ladder 3 or the like input by the firefighter or the like. In this embodiment, the set rotation speed of the hydraulic pump 14 is set to three stages: a first rotation speed which is the lowest rotation speed, a third rotation speed which is the highest rotation speed, and a second rotation speed which is between them. The first rotation speed is set when any one of the operation of raising and lowering the ladder 3, the operation of turning, and the operation of bending is selected, or when the operation of turning and the operation of bending are selected. The second rotation speed is set when the extension / retraction operation of the ladder 3 is selected, when both the hoisting operation and the rotation operation are selected, when both the hoisting operation and the bending operation are selected, or when the extension or jacking up operation of the outrigger 8 is selected. The third rotation speed is set when at least one of the following operations is selected in addition to the telescoping operation: the hoisting operation, the turning operation, the bending operation, and the extension or jacking up of the outriggers 8. In this way, by changing the rotation speed of the hydraulic pump 14 depending on the load, energy can be saved and costs can be reduced compared to when the hydraulic pump 14 is always operated at the maximum rotation speed. The set rotation speed of the hydraulic pump 14 may be changeable in four or more stages or continuously.

[0018] Figure 4 shows the proportional valve circuit and emergency circuit. The proportional valve 18 used to supply oil to the telescopic cylinder 9, derrick cylinder 10, articulating cylinder 11, and swing hydraulic motor 15 is integrally provided with a manual operation lever 19 connected to an emergency circuit, and the emergency circuit is equipped with an orifice 24 that throttles the oil flow rate. A manual operation switch (not shown) is provided to prevent incorrect operation, and when the manual operation switch is turned on, the oil line switching valve unit 25 switches the oil line from the normal circuit to the emergency circuit (manual operation circuit), making it possible to manually operate the ladder 3 using the manual operation lever 19. In addition, automatic stop valves 21 are provided between the proportional valve 18 and the telescopic cylinder 9, the elevation cylinder 10, and the bending cylinder 11, and when a ladder monitoring device (not shown) detects that the movement of the ladder 3 in the extension or lowering direction exceeds a predetermined range, it controls the automatic stop valves 21 to stop the supply of oil to each cylinder. In this way, by integrating the proportional valve 18 used during normal operation with the manual operating lever 19 for manually operating the ladder 3 to store when normal operation is not possible due to a malfunction, loss of power, etc., into a proportional valve with a manual operating lever, space can be saved. Furthermore, if the emergency circuit and the proportional valve 18 are provided separately, a manually operated valve suitable for the flow rate of the emergency circuit can be used, but this is not possible if the proportional valve 18 and the manual operation lever 19 are integrated. Therefore, by providing an orifice 24 in the emergency circuit to restrict the flow rate as in this embodiment, the operating speed of the ladder 3 during manual operation can be suppressed, preventing the ladder 3 from moving at a speed greater than a predetermined speed. Furthermore, during normal operation, if the ladder 3 reaches a dangerous angle that could cause the vehicle to tip over, it is electronically controlled to automatically limit the movement of the ladder 3, but in addition to this, by integrating the proportional valve 18 and manual operation lever 19 and installing automatic stop valves 21 between each cylinder, the ladder monitoring device will automatically cut off the oil supply to each cylinder if the ladder 3 reaches a dangerous angle, not only during manual operation but also during normal operation. This double safety control further improves safety.

[0019] FIG. 5 is a diagram showing the circuit of the telescopic cylinder. The hydraulic circuit is provided with counterbalance valves 26 used to maintain the positions of the pair of left and right telescopic cylinders 9. In Figure 5, the counterbalance valve 26 on the left is for the retraction direction, and the counterbalance valve 26 on the right is for the extension direction. A flexible hydraulic hose is used to connect the telescopic cylinder 9 and the counterbalance valve 26, rather than a steel pipe, etc. This prevents the connection between the telescopic cylinder 9 and the counterbalance valve 26 from coming loose due to the cylinder swinging. A check valve 27 is also installed between the telescopic cylinder 9 and the counterbalance valve 26. This allows the check valve 27 to stop the flow of oil, even if the hydraulic hose were to burst due to aging or other reasons, thereby maintaining the position of the telescopic cylinder 9. The load on the telescopic cylinder 9 is greater in the extension direction than in the retraction direction. However, the counterbalance valve 26 maintains its own weight and the reaction force when water is released, so the telescopic cylinder cannot be retracted unless the counterbalance valve 26 is opened. This means that the operating pressure is higher in the retraction direction than in the extension direction. However, by installing the check valve 27, the check valve 27 can stop the oil until the cylinder starts to move in the retraction direction, so no load is placed on the counterbalance valve 26 and the operating pressure can be reduced. When the telescopic cylinder 9 retracts, the counterbalance valve 26 opens when the sum of the hydraulic pressure applied to the check valve of the counterbalance valve 26 on the right side in Figure 5 and the pressure at which the cylinder retracts reaches the set pressure. Furthermore, when hydraulic pressure is applied in the contraction direction, the check valve 27 opens, allowing oil to be discharged from the cylinder. [Explanation of symbols]

[0020] 2. Body 3 ladder 8 Outriggers 9 Telescopic Cylinder 10. Drilling cylinder 11 Refraction Cylinder 12 Outrigger cylinder 121 Extension side oil chamber 122 Contraction side oil chamber 123 Outrigger switching valve 13 Oil Tank 14 Hydraulic pump 15 Swing hydraulic motor 16 High pressure module (manifold block) 17 Low pressure module (manifold block) 18 Proportional valve 19 Manual operation lever 23 Outrigger speed increase switching valve 24 Orifice 26 Counterbalance valve 27 Check valve

Claims

1. a ladder or boom mounted on the vehicle; Multiple outriggers are provided on both the left and right sides of the vehicle body, a hydraulic outrigger cylinder used to extend the outrigger, the hydraulic outrigger cylinder having an extension-side oil chamber to which oil is supplied when the outrigger is extended and a retraction-side oil chamber to which oil is supplied when the outrigger is retracted; an oil tank in which the oil to be supplied to the outrigger cylinder is stored; a hydraulic pump that pressurizes the oil sucked up from the oil tank; an outrigger acceleration switching valve that is provided in a pipe connected to the outrigger cylinder and switches a destination of the oil discharged from the contraction-side oil chamber of the outrigger cylinder from the oil tank to the extension-side oil chamber; a controller for controlling the hydraulic circuit, when an operation to move one of the plurality of outriggers provided on the left side or one of the plurality of outriggers provided on the right side toward the extension side is selected, the controller turns off the outrigger acceleration switching valve to direct the destination of the oil discharged from the retraction-side oil chamber of the outrigger cylinder to the oil tank, A ladder / boom-equipped vehicle characterized in that, when an operation is selected to simultaneously move two or more of the multiple outriggers provided on the left side or two or more of the multiple outriggers provided on the right side toward the extension side, the outrigger acceleration switching valve is turned on so that the destination of the oil discharged from the retraction-side oil chamber of the outrigger cylinder is the extension-side oil chamber.

2. a hydraulic telescopic cylinder used to extend or retract the ladder or the boom; a hydraulic hoisting cylinder used to hoist the ladder or the boom; A hydraulic refraction cylinder used to refraction the refraction stage provided at the tip of the ladder or the boom; a proportional valve that controls the amount of oil supplied to the telescopic cylinder, the elevation cylinder, or the articulation cylinder; a manual operation lever that is integral with the proportional valve and is connected to an emergency circuit, 2. A ladder / boom-mounted vehicle according to claim 1, wherein the emergency circuit is provided with an orifice for throttling the flow rate of the oil.

3. a counterbalance valve used to maintain the position of the telescopic cylinder; The telescopic cylinder and the counterbalance valve are connected by a flexible hose, 3. The ladder / boom-equipped vehicle according to claim 2, wherein a check valve is provided between the telescopic cylinder and the counterbalance valve.

4. The hydraulic circuit includes a low-pressure circuit and a high-pressure circuit, The oil at a high pressure of 22 MPa or more flowing through the high-pressure circuit is supplied to the telescopic cylinder, the elevation cylinder, and the bending cylinder, The oil at a low pressure of less than 22 MPa flowing through the low-pressure circuit is supplied to the outrigger cylinder, The manifold block in the high-pressure circuit is made of iron, 4. A ladder / boom-equipped vehicle according to claim 2 or 3, wherein a manifold block in the low-pressure circuit is made of aluminum.

5. a hydraulic rotation motor used to rotate the ladder or the boom; The controller sets the rotation speed of the hydraulic pump to a first rotation speed when any one of the ladder hoisting operation, the swing operation, and the bending operation, or the swing operation and the bending operation, is selected; When any one of the operation of extending and retracting the ladder, the operation of raising and lowering the ladder and the rotation operation, the operation of raising and lowering the ladder and the bending operation, or the operation of the outrigger is selected, the rotation speed of the hydraulic pump is set to a second rotation speed that is higher than the first rotation speed; A ladder / boom-equipped vehicle as described in any one of claims 2 to 4, characterized in that when at least one of the hoisting operation, the swivel operation, the bending operation, and the outrigger operation is selected in addition to the telescopic operation, a third rotation speed higher than the second rotation speed is set.

Images