JPH0645980U - Work vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] A work vehicle in which a hydraulic drive from a hydraulic pump driven by an engine mounted on the vehicle drives a vehicle to drive and a working machine provided on the vehicle. A hydraulic cylinder for operating the accelerator of the engine, an engine rotation adjusting means for outputting an engine rotation adjustment signal, an operation position detector for detecting an operation position of the hydraulic cylinder and outputting a feedback signal, the adjustment signal and the feedback In a work vehicle provided with an engine rotation control means for receiving a signal and outputting a signal for controlling driving of the hydraulic cylinder, there is provided a work vehicle capable of controlling the engine rotation so that the work vehicle can travel and move even if the engine rotation control means fails. The purpose is to provide. A second engine rotation adjusting means is provided for detecting that the working vehicle is in a running state by a running state detecting means, and directly controlling the hydraulic cylinder at this time so as to rotate the work vehicle to an engine speed capable of traveling. thing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is configured such that a hydraulic motor is driven by a hydraulic power source from a hydraulic pump driven by an engine mounted on a vehicle so that the vehicle can be driven to travel, and a working machine is provided on the vehicle to provide a hydraulic power source from the hydraulic pump. The present invention relates to a work vehicle configured to drive the work machine according to

[0002]

[Prior art]

 As a work vehicle of this type, a conventional technique will be described by taking a crane vehicle as shown in FIG. 3 as an example. As shown in FIG. 2 and FIG. 3, the mobile crane drives the hydraulic motors 4, 4 by the hydraulic power source from the hydraulic pump 3 driven by the engine 2 mounted on the vehicle 1, and through the crawlers 5, 5. The vehicle 1 is configured such that it can be driven to run, and the vehicle 1 is provided with a retractable boom 6 which can be raised and retracted and extended by a hydraulic power source from the hydraulic pump 3.

That is, the telescopic boom 6 is provided with a post 7 which can be swiveled on the vehicle 1 and a first telescopic boom 8 whose base end is rotatably supported by the post 7 and the first telescopic boom 8. The boom 8 has a second telescopic boom 9 pivotally supported at its base end so that it can be undulated. A hoisting hydraulic cylinder 10 is arranged at an appropriate position between the first telescopic boom 8 and the post 7 so that the first telescopic boom 8 can be hoisted and driven with respect to the post 7. A bending hydraulic cylinder 11 via a link is arranged at an appropriate position between the first telescopic boom 8 and the second telescopic boom 9 so that the second telescopic boom 9 can be bent and driven with respect to the first telescopic boom 8. . The first telescopic boom 8 and the second telescopic boom 9 can be telescopically driven by inserting and retracting a plurality of booms and telescopically, and providing an appropriate telescopic drive means (not shown) such as a hydraulic cylinder for telescopic movement between the booms. I have to.

A winch 12 is arranged on the base end side boom of the first telescopic boom 8, and the wire rope 13 unwound from the winch 12 is moved along the first telescopic boom 8 and the second telescopic boom 9 to make a second telescopic boom. The hook 14 is connected to the tip of the boom 9, and the hook 14 is connected to the tip of the boom 9 to suspend the hook 14 from the tip of the second telescopic boom 9. When crane work is performed with the mobile crane configured as described above, the telescopic boom 6 is appropriately extended / retracted, raised / lowered, and swung, and the winch 12 is operated to position the hook 14 at an appropriate position and perform crane work. Is.

Further, in order to ensure the stability of the vehicle 1 during the crane work, the crane vehicle is equipped with an outrigger device. This outrigger device is composed of a slide beam 15 having its base end attached to the vehicle 1 and extending from the side of the vehicle 1 and a jack 16 attached to the tip of this slide beam 15, and is provided at the front, rear, left and right of the vehicle 1. Four units are installed. Here, the slide beam 15 is composed of an outer cylinder beam 15a and an inner cylinder beam 15b which is telescopically inserted into the outer cylinder beam 15a. A sliding hydraulic cylinder 17 is arranged between the outer cylinder beam 15a and the inner cylinder beam 15b. The inner cylinder beam 15b can be extended and retracted more than the outer cylinder beam 15a. Further, the jack 16 is composed of a hydraulic cylinder in the case of the present embodiment, and will be described below as the jack hydraulic cylinder 16.

The jack hydraulic cylinder 16 and the slide hydraulic cylinder 17 are configured to be operable by operating the selection valve 18 and the outrigger operation switching valve 19. That is, the selection valve 18 is composed of a four-port three-position type switching valve, one of the ports of which is connected to the hydraulic pump 3 via the outrigger operation switching valve 19 and the other of which is a tank. Connected to 20. The other two have their ports connected to the extension side oil chambers of the jack hydraulic cylinder 16 and the sliding hydraulic cylinder 17, respectively. The outrigger operation switching valve 19 is composed of a six-port three-position switching valve, two of the ports are connected to the carryover oil passage 21, and the other three are the hydraulic pump 3, the tank 20, and the above-mentioned. Each of them is connected to a selection valve 18, and the other one is connected to the reduction-side oil chambers of the jack hydraulic cylinder 16 and the sliding hydraulic cylinder 17, respectively. Although only one jack hydraulic cylinder 16, one slide hydraulic cylinder 17 and one selection valve 18 are shown in FIG. 2, the remaining three hydraulic cylinders are similarly connected to the oil passage 22.

Next, a swing operation switching valve 23 that controls and operates a swing hydraulic motor 25 that drives the post 7 to swing, and a lift operation that lifts the first telescopic boom 8 by controlling and operating the lift hydraulic cylinder 10. A switching valve for bending operation (which is arranged after the oil passage 21a and is not shown) for controlling the switching valve 24 and the hydraulic cylinder 11 for bending to raise and lower the second expansion boom 9, and the first telescopic boom 8 is expanded and contracted. A first telescopic operation switching valve (which is arranged after the oil passage 21a and is not shown) for controlling and operating the telescopic hydraulic cylinder to be driven, and a second telescopic hydraulic cylinder for controlling the second telescopic boom 9 to telescopically drive. A switching valve for expansion and contraction operation (which is arranged after the oil passage 21a and is not shown) and a switching valve for winches (which is arranged after the oil passage 21a and is not shown) for controlling the winch 12 are arranged. By appropriately operating the switching valve, the telescopic boom 6 is appropriately turned, raised, and retracted, and the winch 12 is operated to perform the crane operation.

Further, travel switching valves 26, 26 for controlling and operating the hydraulic motors 4, 4 when the mobile crane is moved are arranged. That is, the traveling switching valves 26, 26 are composed of four-port three-position switching valves, one of which is connected to the hydraulic power source from the hydraulic pump 3 and the other is connected to the tank 20. . The remaining two ports are connected to the supply / discharge ports of the hydraulic motors 4, 4. By operating the traveling switching valves 26, 26, the hydraulic motors 4, 4 are drive-controlled, and the vehicle 1 can be driven to travel through the crawlers 5, 5.

A work mode switching valve 27 selectively selects a supply destination of a hydraulic pressure source from the hydraulic pump 3 driven by the engine 2 for traveling the crane vehicle and for performing a crane operation. I am trying to switch to. This work mode switching valve 27 is a three-port two-position solenoid switching valve, one of which is connected to the oil passage from the hydraulic pump 3 and the other is connected to the carry-over oil passage 21. The other one is connected to the switching valve 26 for traveling operation. The operation of the traveling operation switching valve 26 can be operated by operating the work mode switching switch 29.

That is, when the work mode changeover switch 29 is turned on and the power from the battery 28 is supplied to the solenoid coil 27a of the work mode changeover valve 27 via the work mode changeover switch 29, the work mode changeover valve 27 is turned on. Switching The hydraulic pressure source from the hydraulic pump 3 is supplied to the traveling operation switching valves 26, 26. On the contrary, when the work mode changeover switch 29 is turned off and the power from the battery 28 is not supplied to the solenoid coil 27a of the work mode changeover valve 27 through the work mode changeover switch 29, the work mode changeover valve 27 is operated. Is arranged in the inside thereof so that the hydraulic source from the hydraulic pump 3 is switched to be supplied to the carry-over oil passage 21 by a spring action.

On the other hand, the accelerator lever 30 of the engine 2 is connected to one end of a swing lever 32 via an operation wire 31. Further, one end 34a of the rod 34 of a hydraulic cylinder 35 having a rod 34 which is constantly urged to one side by a return spring 33 is connected to the middle part of the swing lever 32.

This hydraulic cylinder 35 has two oil chambers, a first oil chamber 35a and a second oil chamber 35b, and the first oil chamber 35a has a first control valve 37 through a first oil passage 36a. However, a second control valve 38 is connected to the second oil chamber 35b via a second oil passage 36b. Each of the control valves 37 and 38 is a three-port two-position type switching valve having solenoid coils 39 and 40, respectively, and operates in response to a signal from an engine rotation control means 41 described later. The first oil chamber 36a and the second oil chamber 36b can be selectively connected to the hydraulic pump 3 side via a pressure reducing valve 42.

Specifically, in a state where the first oil chamber 35 a side is connected to the hydraulic pump 3 side and the second oil chamber 35 b is connected to the tank 20 side, the rod 34 causes the return spring 33 to be urged by the urging force. Against this, the swing lever 32 rotates in the direction of arrow C, and the accelerator lever 30 is operated in the direction of arrow E for increasing the engine speed. On the other hand, when the first oil chamber 35a is connected to the tank 20 side and the second oil chamber 35b is connected to the hydraulic pump 3 side, the rod 34 moves in the direction of arrow B, and the swing lever 32 moves in the direction of arrow. The accelerator lever 30 is operated in the arrow F direction in which the engine speed is reduced by the spring force of the spring 43 by rotating in the D direction and releasing the tensile force on the operation wire 31.

The engine rotation control means 41 detects a signal from the engine rotation adjustment means 44, which outputs an engine rotation adjustment signal by a manual adjustment operation, and an operating position of the hydraulic cylinder 35, and outputs a feedback signal. In response to a signal from the operating position detector 52, a control signal is output to the solenoid coils 39 and 40 to control the operation of the hydraulic cylinder 35. Specifically, whether or not the hydraulic cylinder 35 is positioned at a position corresponding to the signal from the engine rotation adjusting means 44 is received by a feedback signal from the operating position detector 52, and if not, a response is made. Appropriate control signals are output to the solenoid coils 39 and 40 to operate the hydraulic cylinder 35 to the corresponding position. When the corresponding position is reached, a control signal is output to the solenoid coils 39 and 40 and the hydraulic cylinder 35 is stopped at that position. As a result, the accelerator rotation control means 41 is adapted to perform a control operation. That is, the operator manually adjusts the engine rotation adjusting means 44 as appropriate to operate the hydraulic cylinder 35 in response to the adjustment signal output from the engine rotation adjusting means 44 to adjust the rotation of the engine 2. Is what you are doing.

In the mobile crane constructed as described above, when the mobile crane travels, the work mode selector switch 29 is set to 0N to switch the work mode selector valve 27, and the hydraulic pump 3 driven by the engine 2 is operated. A hydraulic power source is supplied to the traveling operation switching valve 26. The traveling operation switching valve 26 is appropriately switched, the hydraulic motors 4, 4 are rotated, and the crawlers 5, 5 move the crane vehicle forward or backward at an appropriate speed. At this time, the engine rotation adjusting means 44 is manually operated to appropriately adjust the rotation of the engine 2 to adjust the amount of oil discharged from the hydraulic pump 3 and the amount of oil supplied to the hydraulic motors 4 and 4. It is necessary to adjust the speed.

On the other hand, when the crane is operated, the work mode selector switch 29 is set to 0FF, and the hydraulic source from the hydraulic pump 3 driven by the engine 2 is supplied to the carry-over oil passage 21 without switching the work mode selector valve 27. I will let you. Before the crane work, first, the selection valve 18 is selected to operate the slide hydraulic cylinder 17, and the outrigger operation switching valve 19 is appropriately operated to extend the slide beam 15. Next, the selection valve 18 is selected to operate the jack hydraulic cylinder 16, and the outrigger operation switching valve 19 is appropriately operated to extend the jack hydraulic cylinder 16 to extend the outrigger device and support the crane vehicle on the ground. Excuse me. Also at this time, the engine rotation adjusting means 44 is manually operated to appropriately adjust the rotation of the engine 2 to adjust the amount of oil discharged from the hydraulic pump 3, and the slide hydraulic cylinder 17 and the jack hydraulic cylinder 16 are adjusted. It adjusts the amount of oil supplied and adjusts its speed. When the outrigger device is stored, the reverse operation described above may be performed.

When the outrigger operation switching valve 19 is set to the neutral position, the oil discharged from the hydraulic pump 3 is swirling operation switching valve 23, undulating operation switching valve 24, and bending operation switching valve (oil passage). 21a and subsequent elements (not shown), a first expansion / contraction operation switching valve (which is disposed after the oil passage 21a and is not shown), and a second expansion / contraction hydraulic cylinder for expanding / contracting the second expansion / contraction boom 9. 2 The expansion / contraction operation switching valve (which is arranged after the oil passage 21a and is not shown) and the winch switching valve (which is arranged after the oil passage 21a and is not shown) are supplied appropriately. By operating the valve, the expansion / contraction boom 6 is appropriately expanded / contracted, raised / lowered, bent, or swung, and the winch 12 is operated to position the hook 14 at an appropriate position for crane work. Then, similarly to the above, the engine rotation adjusting means 44 is manually operated to appropriately adjust the rotation of the engine 2 to adjust the amount of oil discharged from the hydraulic pump 3, the turning hydraulic motor 25, and the undulating hydraulic cylinder 10. Adjust the amount of oil supplied to each of the bending hydraulic cylinder 11, the telescopic cylinders (not shown) that extend and retract the telescopic boom 6, and the hydraulic motor (not shown) that drives the winch. The speed is adjusted.

[0018]

[Problems to be solved by the device]

 However, the conventional work vehicle thus configured has the following problems. That is, as described above, the rotation control of the engine 2 is controlled by the engine rotation control means 41 on the basis of the manual adjustment from the engine rotation adjustment means 44 in both the traveling movement of the mobile crane and the crane work. Is operated by operating the accelerator lever 30 via the hydraulic cylinder 35. Therefore, when the engine rotation control means 41 fails, the rotation control of the engine 2 becomes impossible, and the crane work as well as the traveling of the crane vehicle becomes impossible. Therefore, in order to repair the breakdown, it is necessary to send service personnel to the breakdown site to repair it, or to take a crane vehicle on another vehicle and transport it to a service factory for repair. Met. It is an object of the present invention to provide a work vehicle which focuses on the above problems and is capable of moving and moving the vehicle by itself even if the engine rotation control means 41 fails.

[0019]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the work vehicle of the present invention is configured such that the hydraulic motor is driven by a hydraulic power source from a hydraulic pump driven by an engine mounted on the vehicle so that the vehicle can be driven and driven. A working vehicle comprising a working machine and capable of driving the working machine by a hydraulic pressure source from the hydraulic pump, the hydraulic cylinder being connected to the accelerator of the engine to operate the accelerator of the engine, and by manually adjusting the hydraulic cylinder. Engine rotation adjusting means for outputting an engine rotation adjustment signal, an operation position detector for detecting an operation position of the hydraulic cylinder and outputting a feedback signal, and the hydraulic cylinder driven by receiving the adjustment signal and the feedback signal. In a work vehicle equipped with engine rotation control means for outputting a control signal, the work vehicle is not in a running state. And a second running state detecting means for detecting the fact that the working vehicle is in a running state, and directly controls the hydraulic cylinder to set the working vehicle to rotate the engine so that the working vehicle can travel. It is characterized by including an engine rotation adjusting means.

[0020]

[Action]

 In the work vehicle of the present invention configured as described above, when the running state detecting means detects that the working vehicle is in the running state, the second engine rotation adjusting means directly controls the hydraulic cylinder to allow the working vehicle to move. Therefore, when the work vehicle is driven, the engine rotation adjusting means is not used and the second engine rotation adjusting means can control the rotation of the engine to move the vehicle. Therefore, even if the engine rotation control means breaks down, the work vehicle can be moved without any hindrance.

[0021]

【Example】

 An embodiment of the work vehicle of the present invention will be described below with reference to FIG. 1 by taking a crane truck as an example. It should be noted that the reference numerals other than the reference numeral 41 shown in FIGS. 2 and 3 and described in the related art will be used in the following description as the same reference numerals. Therefore, detailed description of these reference numerals is omitted.

First, in explaining the embodiment according to the present invention, it is explained that the rotation of the engine 2 is generally set as follows. In other words, the rotation of the engine required to move the work vehicle requires a torque as compared with the rotation of the engine required for crane work, and thus requires a high rotation. In other words, when determining the capacity of the engine mounted on the work vehicle, it is determined from the torque required when the work vehicle travels. Therefore, the hydraulic cylinder 35 is adjusted so that the rotation of the engine 2 becomes substantially the maximum rotation (for example, 3000 rpm) when it is operated in the direction of arrow A to the stroke end. The engine 35 is operated up to the stroke end so that the engine 2 is rotated so as to reach the maximum speed.

Reference numeral 45 denotes an outrigger operation detecting means which is composed of a potentiometer, a limit switch and the like, and detects that the outrigger operation switching valve 19 is operated. Reference numeral 46 denotes a turning operation detecting means which includes a potentiometer, a limit switch and the like, and detects that the turning operation switching valve 23 is operated. Reference numeral 47 denotes an undulation operation detecting means which is composed of a potentiometer, a limit switch, and the like, and detects that the undulation operation switching valve 24 is operated. Similarly, although not shown, detection means for detecting the operation is also arranged in each of the folding operation switching valve, the first expansion / contraction operation switching valve, the second expansion / compression operation switching valve, and the winch switching valve. is doing.

Reference numeral 48 denotes an engine rotation control means, which has the following functions added to those described in the related art. That is, when the operation signal from the outrigger operation detecting means 45 is received, the signal output from the engine rotation control means 48 to the solenoid coils 39, 40 indicates that the maximum rotation of the engine 2 is a predetermined rotation value (eg, 2500 rpm). ) It is designed to control so that it is output only below. Further, when an operation signal is received from the detecting means for detecting the operation of each switching valve such as the turning operation detecting means 46, the undulating operation detecting means 47, etc., the engine rotation adjusting means 48 causes the solenoid coil 39, The signal output to 40 is controlled so that the maximum rotation of the engine 2 is output only below a predetermined rotation value (for example, 2000 rpm). Therefore, even if the engine rotation adjusting means 44 is manually adjusted to maximize the engine rotation, when the above operation is performed, the operation can be performed only at a predetermined value or less.

Reference numeral 49 denotes a second engine rotation adjusting means, which is composed of a switch 50 and a relay 51. The relay 51 is connected to the battery 28 via a series circuit of a switch 50 and the work mode changeover switch 29. Therefore, the relay 51 is operated by turning on the work mode changeover switch 29 and turning on the switch 50. Here, the work mode changeover switch 29 is a switch that is turned on when the work vehicle is moved to travel as described above, and is a running state detecting means for detecting that the work vehicle is in the running state (utility model registration claim range). The traveling state detecting means) described in (1). (In the following description, the work mode selector switch 29 will be described.)

Reference numeral 51 b 1 is a normally closed contact of the relay 51, and is inserted in the middle of an electric circuit for transmitting an output signal from the engine rotation control means 48 to the solenoid coil 39. 51 Ra is a normally open contact of the relay 51, and has one end connected to the solenoid coil 39 and the other end connected to the battery 28. 51Rb2 is a normally closed contact of the relay 51, and is inserted in the middle of an electric circuit for transmitting the output signal from the engine rotation control means 48 to the solenoid coil 40.

The work vehicle of the present invention thus constructed operates as follows. First, when the mobile crane is moved, the work mode selector switch 29 is turned on. Then, the working mode switching valve 27 is switched, and the oil discharged from the hydraulic pump 3 is supplied to the traveling operation switching valves 26, 26, and the hydraulic motors 4, 4 are driven by operating the traveling operation switching valves 26, 26. The mobile crane is moved via the crawlers 5 and 5. At this time, the rotation of the engine 2 can be maximized by turning on the switch 50.

That is, when the switch 50 is turned on, the relay 51 is actuated to open the relay contacts 51Rb1 and 51Rb2 and to close 51Ra, so that the power of the battery 28 is supplied to the solenoid 39, The output signal from the engine rotation control means 48 is not transmitted to the solenoid 38. Therefore, the first control valve 37 is switched to supply the hydraulic pressure source from the hydraulic pump 3 to the first hydraulic chamber 35a of the hydraulic cylinder 35 via the first hydraulic passage 36a. Since the second control valve 38 does not switch, the oil in the second oil chamber 35b of the hydraulic cylinder 35 escapes to the tank 20 via the second oil passage 36b, and the rod 34 of the hydraulic cylinder 35 is closed by the arrow A. Move in the direction. As a result, the swing lever 32 is swung in the direction of arrow C, and the accelerator lever 30 is swung in the direction of arrow E through the operation wire 31 to raise the rotation of the engine 2.

Since the switch 50 is kept in the ON state when the work vehicle is moved, the hydraulic cylinder 35 continues to be moved only in the direction of arrow A, and the hydraulic cylinder 35 moves in the direction of arrow A. It will move and will eventually maintain the stroke end state. That is, the engine 2 is set to a state in which the engine 2 is rotated at the maximum speed. In this way, when the work vehicle travels, the second engine rotation adjusting means 49 adjusts the rotation of the engine 2 to travel.

Next, a case of performing a crane operation will be described. In this case, since the work mode switching switch 29 is turned off and the work mode switching valve 27 is not switched, the discharge pressure from the hydraulic pump 3 is supplied to the carryover oil passage 21. Then, the switching valve 19 for operating the outrigger is operated to extend and retract the outrigger device. Further, the turning operation switching valve 23, the up-and-down operation switching valve 24, the bending operation switching valve (which is arranged after the oil passage 25 and is not shown), and the first telescopic operation switching valve (which is arranged after the oil passage 25). (Not shown), a second telescopic operation switching valve (not shown in the drawings that is arranged after the oil passage 25) for controlling and operating the telescopic hydraulic cylinder that drives the second telescopic boom 9 to extend and retract, and a winch switch. Crane work is performed by appropriately operating a valve (which is arranged after the oil passage 25 and is not shown).

Since the switch 50 is turned off at this time, the relay 51 does not operate, the relay contacts 51Rb1 and 51Rb2 are closed, and the relay contact 51Ra is opened. Therefore, the rotation of the engine 2 is controlled by manually adjusting the rotation of the engine 2 by the engine rotation adjusting means 44 in the same manner as described in the related art so that a signal is output from the engine rotation control means 48 and the hydraulic cylinder sillider 35 is operated. . In this case, even if the switch 50 is forgotten to be turned off, the work mode switching switch 29 is always turned off when the crane is operated, so the relay 51 does not operate. In other words, the switch 50 is not always necessary, and the relay 51 may be operated in cooperation with the work mode changeover switch 29.

With the above-described operation and configuration, even if the engine rotation control means 48 fails and the engine rotation adjusting means 44 cannot adjust the rotation of the engine 2, the second engine rotation speed can be maintained during traveling. The rotation of the engine 2 can be adjusted by the adjusting means 49, and only traveling movement can be performed.

In the above embodiment, the work mode switching valve 27 is switched between the traveling operation and the crane operation so that the oil discharged from the hydraulic pump 3 is supplied to each operation switching valve. Instead of using the work mode switching valve 27, the traveling operation switching valve 26 may be interposed between the hydraulic pump 3 and the outrigger operation switching valve 19. In this case, at the neutral position of the traveling operation switching valve 26, a carryover circuit may be provided so that the oil discharged from the hydraulic pump 3 is supplied to the outrigger operation switching valve 19. Therefore, it has a hydraulic circuit that prioritizes traveling movement over crane work. The present invention can be implemented even with such a hydraulic circuit. That is, the fact that the traveling operation switching valve 26 has been operated is detected by a detector (a traveling state detecting means described in the utility model registration claim) composed of a switch or the like, and the relay 51 is operated based on the detection result. You can leave it as it is.

Further, in the above-described embodiment, the vehicle in which the crawler is driven by the hydraulic motor to move the vehicle has been described, but it goes without saying that it may be a vehicle in which the wheel is driven by the hydraulic motor to move the vehicle. Furthermore, in the above-mentioned embodiment, the crane vehicle having the crane as the working machine has been described as an example. It is needless to say that the same can be carried out even if there is a working machine such as.

[0034]

[Effect of device]

 The work vehicle of the present invention constructed and operated as described above can only travel by itself even if the engine rotation control means fails. Therefore, when repairing a failure, avoid the situation in which the service person must receive repairs at the failure site or the situation where the work vehicle is mounted on another vehicle and transported to a service factory for repair. it can.

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating a work vehicle of the present invention.

FIG. 2 is an explanatory diagram illustrating a conventional work vehicle.

FIG. 3 is an explanatory diagram illustrating a crane vehicle as an example of a work vehicle.

[Explanation of symbols]

 1 Vehicle 2 Engine 3 Hydraulic Pump 4 Hydraulic Motor 6 Telescopic Boom 29 Traveling State Detection Means 30 Accelerator 35 Hydraulic Cylinder 44 Engine Rotation Adjustment Means 52 Operating Position Detector 48 Engine Rotation Control Means 49 Second Engine Rotation Adjustment Means

Claims (1)

[Scope of utility model registration request] 1. A hydraulic motor is driven by a hydraulic power source from a hydraulic pump driven by an engine mounted on the vehicle so that the vehicle can be driven to travel, and a working machine is provided on the vehicle to provide hydraulic pressure from the hydraulic pump. A work vehicle configured to be able to drive the working machine by a power source, the hydraulic cylinder being connected to the accelerator of the engine to operate the accelerator of the engine, and the engine rotation adjustment that outputs an adjustment signal of the engine rotation by manual adjustment. Means, an operating position detector for detecting an operating position of the hydraulic cylinder and outputting a feedback signal, and an engine rotation control means for outputting a signal for driving and controlling the hydraulic cylinder in response to the adjustment signal and the feedback signal. In the working vehicle, a running state detecting means for detecting that the working vehicle is in a running state, and And a second engine rotation adjusting means for directly controlling the hydraulic cylinder to make the engine rotation of the work vehicle movable when the running state detection means detects that the work vehicle is in the running state. And a working vehicle.