JP6170801B2 - Control device for work vehicle - Google Patents

Description

  The present invention relates to a control device for a working vehicle, which includes a working device that receives a supply of hydraulic oil to perform a predetermined work, a working pump that supplies the working device with the working oil, and an engine that rotationally drives the working pump. About.

  As an example of such a working vehicle, a boom provided on a traveling body so as to be freely raised, retracted (or bent) and swiveled, a workbench provided at the tip of the boom, a boom provided on the workbench There is an aerial work vehicle equipped with a boom operating device for operating the hoisting motion, telescopic motion and turning motion. In such an aerial work vehicle, a hydraulic pump (working pump) is driven using engine power, and the hydraulic oil discharged from the hydraulic pump is supplied in an amount and direction according to the operation of the boom operating device. The hoisting cylinder, the telescopic cylinder, and the swing motor (hereinafter collectively referred to as “boom actuator”) provided in the hoisting cylinder are moved up and down, telescopically moved, and swung to move the work platform to a desired height. Those configured to be moved to a certain position are known.

  In an aerial work vehicle that performs work using engine power in this way, the engine drive noise may become noise and become a problem. Therefore, in consideration of the working environment, the engine rotation speed is always low, regardless of the amount of operation of the boom operating device so that the engine drive noise is reduced, and the engine rotation speed is emphasized. There is known one configured so that any one of automatic modes in which a number is always rotated at a high rotation number can be selected. In addition, by controlling the amount of hydraulic oil supplied to the boom actuator and the engine speed in response to changes in the amount of operation of the boom operating device, the boom actuator can be operated in accordance with the amount of operation of the boom operating device. There is also known one configured to be able to optimize the amount of oil supplied and to suppress waste of energy consumed by the engine (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2002-47000

  By the way, in an aerial work vehicle such as the above, horizontal / vertical movement control that moves the work table horizontally or vertically by simultaneously moving the work table up and down, and moving the work table by moving the boom up and down, for example. If the work platform is about to exceed the allowable movement range (the work range set so that the work vehicle can be safely operated without being unstable), the boom is reduced. Non-stop control for moving the work table so that the work table does not exceed the allowable movement range, for example, when the work table is moved by extending the boom, the work table is moved to the end of the allowable movement range. A deceleration / stop system that decelerates the moving speed of the workbench (boom extension speed) as it approaches the section, and stops the movement of the workbench (boom elongating movement) when the workbench approaches the allowable movement range. There is a configuration to perform. Such horizontal / vertical movement control, non-stop control, deceleration / stop control, etc. are controls that automatically operate the boom by controlling the supply of hydraulic oil and controlling the engine speed without corresponding to the operation of the boom operating device. Is to do. As described above, since the engine speed changes without corresponding to the operation of the boom operating device, there is a problem that the operator may feel uncomfortable or may be mistaken for a failure.

  The present invention has been made in view of such problems, and a control device for a working vehicle that can prevent a worker from feeling uncomfortable or misidentified as a failure in automatic operation control of the working device. The purpose is to provide.

  In order to solve the above-mentioned problems, the present invention operates a traveling body, a working device that receives a supply of hydraulic oil and performs a predetermined work (for example, the boom 30 and the work table 40 in the embodiment), and the working device. A control device for a work vehicle including a work pump that supplies oil (for example, the first hydraulic pump P1 in the embodiment) and an engine that drives the work pump, and operates the work device. Work operation means (for example, the raising / lowering operation lever 51 and the telescopic operation lever 52 in the embodiment) and proportional supply for supplying hydraulic oil from the work pump to the work device according to the operation of the work operation means Control means for operating the work device by performing stepless control for controlling the engine speed and continuously changing the rotational speed of the engine (for example, an embodiment) Comprising a worktable movement control unit 71) and in. The work control means is configured to perform automatic operation control of the work device by performing automatic supply control for supplying hydraulic oil different from the proportional supply control under a predetermined condition. The automatic operation control is configured to control the rotational speed of the engine by multi-stage control that changes the rotational speed of the engine in multiple stages instead of the stepless control.

  As the automatic operation control described above, for example, in a boom-type aerial work vehicle, horizontal / vertical movement control for moving the work table horizontally or vertically by simultaneously raising and lowering the boom and extending and retracting, for example, a boom is used. When moving the work table by moving up and down, the work table exceeds the allowable movement range (the work range set so that the work vehicle can be safely operated without being unstable) Then, non-stop control to move the work table so that the work table does not exceed the allowable movement range by reducing the boom, and when the work table is moved by extending the boom, for example, When the platform approaches the end of the allowable movement range, the moving speed of the work table (boom extension speed) is decelerated. For example, a deceleration / stop control for stopping the long movement), an automatic storage control for storing the boom and the workbench in a predetermined storage position on the vehicle body by simultaneously performing the raising / lowering movement, the expansion / contraction movement and the turning movement of the boom. it can.

  In the control device for a work vehicle having the above-described configuration, the work control means controls the engine speed by the stepless control for a predetermined time from the start of the automatic operation control in the automatic operation control. It is preferable that the engine speed be controlled by the multi-stage control instead of the stepless control after the predetermined time has elapsed. Further, it is preferable that the engine speed is controlled by the stepless control instead of the multistage control for a predetermined time immediately before the stop of the automatic operation control.

  Further, in the control device for a work vehicle having the above-described configuration, the work control unit is configured to perform the multi-stage control by changing a change rate when changing the engine speed in the multi-stage control. It is preferred that

  Further, in the control device for a work vehicle having the above-described configuration, the work control means gradually increases the engine speed over a predetermined time when the work operation means is stopped by the work operation means. It is preferable that the control is performed to reduce the idling speed. Alternatively, it is preferable that the engine speed be maintained at a predetermined speed greater than the idling speed for a predetermined time, and then controlled so as to decrease to the idling speed.

  Further, in the control device for a working vehicle having the above-described configuration, the traveling body includes a traveling device (for example, the traveling motor 14 in the embodiment) that travels by receiving the supply of hydraulic oil, and supplies the operating oil to the traveling device. A traveling pump to be supplied (for example, the second hydraulic pump P2 in the embodiment) is provided, and the engine is configured to drive the working pump and the traveling pump. A travel operation means (for example, travel operation lever 55 in the embodiment) for operating the travel apparatus and supply of hydraulic oil from the travel pump to the travel apparatus in accordance with the operation of the travel operation means. And travel control means (for example, travel control unit 72 in the embodiment) for operating the travel device by performing control to change the engine speed, and by the travel control means When the operation control of the travel device is performed, the operation control means restricts control for changing the engine speed, and the travel control means changes the engine speed in accordance with the operation of the travel operation means. It is preferable that the control is prioritized.

  Further, in the control device for a work vehicle having the above-described configuration, the work control means performs the proportional supply control of hydraulic oil and the stepless control of the engine speed to operate a predetermined actuator in the work device. And controlling the flow rate of hydraulic fluid supplied to the predetermined actuator to ensure the flow rate of hydraulic fluid supplied to the other actuator when operating another actuator in the work device It is preferable that the control is performed to operate the other actuator and to perform control to maintain the rotational speed before operating the other actuator without changing the rotational speed of the engine.

  In the control device for a work vehicle according to the present invention, in the automatic operation control of the work device, in place of the stepless control for changing the engine speed continuously, the multistage for changing the engine speed in multiple steps. The engine speed is configured to be controlled by the control. Therefore, in the automatic operation control of the work device, the frequency with which the engine speed changes can be suppressed as compared with the conventional configuration in which the engine speed is changed by stepless control. Therefore, it is possible to prevent the worker from feeling uncomfortable or being mistaken for a failure.

  Further, the engine speed is controlled by the stepless control for a predetermined time from the start of the automatic operation control of the working device, and the engine is controlled by the multistage control instead of the stepless control after the predetermined time has elapsed. Preferably, the engine speed is controlled by the stepless control instead of the multistage control for a predetermined time immediately before the stop of the automatic operation control. Preferably, it is configured. When the operation is started and stopped by the automatic operation control of the work device, the change width of the engine speed increases. When the engine speed is controlled by the multistage control at the start and stop of the operation, the engine speed may change in multiple stages in a short time, resulting in an unpleasant engine drive sound. Therefore, according to the above configuration, since the engine speed is changed continuously (smoothly), it is possible to prevent the driving sound of the engine from becoming an annoying sound.

  Further, if the multi-stage control can be performed by changing the rate of change when changing the engine speed in the multi-stage control, the change in the engine speed in the multi-stage control is smoothed. The engine drive sound can be smoothly changed.

  Further, it is preferable that when the operation stop operation of the work device is performed by the work operation means, control is performed to gradually reduce the engine speed to the idling speed over a predetermined time, or It is preferable that the engine speed be maintained at a predetermined speed greater than the idling speed for a predetermined time, and then controlled to decrease to the idling speed. The allowable torque of the engine also changes at the same time due to the change in the engine speed when the operation of the work device is stopped. Therefore, according to the above configuration, even when the engine has a small allowable torque at the idling speed, it is possible to prevent the engine from stalling when the operation apparatus is stopped.

  In addition, when the travel control means performs the operation control of the travel device, the work control means restricts the control for changing the engine speed, and the travel control means changes the engine speed according to the operation of the travel operation means. It is preferable that the control is prioritized. With this configuration, for example, when the working device is to be operated during traveling, the engine speed increases due to the operation, and the traveling speed increases due to the increase in the engine speed. This can be prevented.

  Further, when operating another actuator in the work device, control is performed to ensure a flow rate of the hydraulic oil supplied to the other actuator by limiting a supply amount of the hydraulic oil to the operating actuator, and to perform the control. It is preferable that the control is performed so as to perform the control to maintain the rotational speed before operating the other actuator without changing the rotational speed of the engine. In the conventional control, control for reducing the engine speed is performed in response to limiting the amount of hydraulic oil supplied to the operating actuator. Therefore, an operation for operating another actuator is performed and an operation input is performed. Despite the increase, the engine speed decreased, causing the operator to feel uncomfortable. However, according to the above configuration, the engine speed is maintained even if the amount of hydraulic oil supplied to the operating actuator is limited, so that it is possible to prevent the operator from feeling uncomfortable as described above.

It is a side view of an aerial work vehicle which is an example of a work vehicle provided with a control device according to the present invention. It is a block diagram which shows the structure of the drive part which drive | works an aerial work vehicle, and the structure of the drive part which drives an aerial work apparatus. It is a graph which shows the relationship between the total supply amount of hydraulic fluid at the time of normal operation control, and an engine speed. It is a graph which shows the relationship between the total supply amount of hydraulic fluid at the time of automatic operation control, and an engine speed. It is a graph which shows an example of the state of the operation input at the time of performing automatic operation control by the control apparatus which concerns on this invention, target speed (operation speed), required flow volume (total supply amount), and engine speed. It is a graph which shows an example of the state of the operation input at the time of performing interlock control by the control apparatus which concerns on this invention, target speed (operation speed), required flow volume (total supply amount), and engine speed.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. First, as an example of a working vehicle provided with a control device according to the present invention, an overall configuration of an aerial work vehicle 1 in which an aerial work device is mounted on a traveling body will be described with reference to FIG.

  The aerial work vehicle 1 is attached to a traveling body 10 including a pair of left and right front wheels 11 and a rear wheel 12, a revolving body 20 provided on the traveling body 10, and a foot pin 21 on the revolving body 20 so as to be raised and lowered. The boom 30 and a work board 40 for boarding a worker attached to the tip of the boom 30 are configured.

  The traveling body 10 is provided with a traveling motor 14, and the traveling motor 10 is configured to be able to travel by rotating the left and right rear wheels 12 by the traveling motor 14. Further, the traveling body 10 is provided with a steering cylinder 15 (hydraulic cylinder). The steering cylinder 15 steers the traveling body 10 by changing the direction of the left and right front wheels 11 via a link mechanism and a rod (not shown). It is configured to be able to do.

  The swivel body 20 is attached to the traveling body 10 so as to be able to swivel around a vertical axis by 360 degrees, and is configured to be able to swivel the swiveling body 20 in a horizontal plane by a swiveling motor 13 provided in the traveling body 10. . The boom 30 is configured by combining a plurality of boom members in a nested manner, and is configured to be extendable and contractable by an extendable cylinder 31 provided in the boom 30. Further, a hoisting cylinder 22 is provided between the swing body 20 and the boom 30, and the hoisting cylinder 22 is configured to be able to hoist the boom 30 in the upper and lower surfaces.

  A vertical post 32 is attached to the tip of the boom 30 so as to be swingable within the undulating surface of the boom 30. The vertical post 32 swings so as to be always extended and positioned in a substantially vertical direction regardless of the undulation angle of the boom 30 by a leveling cylinder (not shown) straddling the tip of the boom 30. It is controlled (leveling control). The work table 40 is attached to the vertical post 32 via a work table support bracket 41 so as to be horizontally swivelable, and is swung horizontally with respect to the vertical post 32 by a swing motor 41 provided in the work table support bracket 41. (Swinging operation) is possible.

  An operation box 50 is provided on the work table 40. As shown in FIG. 2, the operation box 50 includes a raising / lowering operation lever 51 for performing the raising / lowering operation of the boom 30, an expansion / contraction operation lever 52 for performing the expansion / contraction operation of the boom 30, and the boom 30 (swivel body 20). Are provided with a turning operation lever 53 for performing a turning operation of the work table 40 and a swinging operation lever 54 for performing a swing operation of the work table 40. When the hoisting operation lever 51 is tilted forward or backward, an operation command signal for raising or lowering the boom 30 by extending or retracting the hoisting cylinder 22 at an operating speed corresponding to the operation amount is output. When the telescopic operation lever 52 is tilted forward or backward, an operation command signal for contracting or extending the telescopic cylinder 31 at an operating speed corresponding to the operation amount to contract or extend the boom 30 is output. When the turning operation lever 53 is tilted leftward or rightward, the boom motor 30 is turned leftward or rightward by rotating the turning motor 13 forward or backward at an operation speed corresponding to the operation amount. A command signal is output. When the swing operation lever 54 is tilted leftward or rightward, the swing motor 42 is rotated forward or backward at an operation speed corresponding to the operation amount to move the work table 40 leftward or rightward. An operation command signal for swinging (turning) is output. These operation command signals are input to the work table movement control unit 71 of the controller 70. Further, the operation box 50 is provided with a horizontal / vertical operation switch 59 for moving the work table 40 horizontally or vertically by simultaneously raising and lowering the boom 30 and operating signals of the switch 59 are also operated. It is input to the table movement control unit 71.

  The operation box 50 includes a traveling operation lever 55 for performing a traveling operation (starting, stopping, and speed adjusting operation during traveling) of the traveling body 10 and a steering operation lever 56 for performing a steering operation of the traveling body 10. And are provided. When the traveling operation lever 55 is tilted forward or backward, an operation command signal for rotating the traveling motor 14 forward or backward at a traveling speed corresponding to the operation amount to advance or reverse the traveling body 10 is output. The When the steering operation lever 56 is tilted to the left or right, the steering cylinder 15 is extended or contracted at an operating speed corresponding to the operation amount, and the direction of the left and right front wheels 11 is changed to the left or right. An operation command signal for steering the body 10 is output. Each of these operation command signals is input to the travel control unit 72 of the controller 70. Further, the operation box 50 is provided with an engine start switch 57 for starting the engine E and an engine stop switch 58 for stopping the engine E. The operation signals of these switches 57 and 58 are supplied from the controller 70. The engine control unit 73 is input.

  The controller 70 includes a work table movement control unit 71, a travel control unit 72, an engine control unit 73, a position calculation unit 74, and a storage unit 75. The engine control unit 73 performs control to start the engine E when the engine start switch 57 is pushed and to stop the engine E when the engine stop switch 58 is pushed. When the engine E is started, the first and second hydraulic pumps P1 and P2 are driven by the engine E, and hydraulic oil is discharged from the hydraulic pumps P1 and P2. The hydraulic oil discharged from the first hydraulic pump P1 into the first pump oil passage L1 passes through the hoisting control valve 61, the telescopic control valve 62, the swing control valve 63, and the swing control valve 64, and the hoisting cylinder 22 and the telescopic cylinder. 31, the swing motor 13, and the swing motor 42. The hydraulic oil discharged from the second hydraulic pump P2 into the second pump oil passage L11 is supplied to the travel motor 14 and the steering cylinder 15 via the travel control valve 65 and the steering control valve 66, respectively.

  When the operation levers 51 to 54 are operated by the worker M who has boarded the work table 40, the work table movement control unit 71 electromagnetically drives the control valves 61 to 64 according to the operation command signal, Control is performed to supply hydraulic oil from the first hydraulic pump P <b> 1 to the telescopic cylinder 31, the swing motor 13, and the swing motor 42. And it is comprised so that each actuator may be operated with the operation direction and operation speed according to the operation direction and operation amount of the operation levers 51-54, and the work table 40 may be moved. Further, when the telescopic operation lever 52 is operated in a state where the horizontal / vertical operation switch 59 is turned on, the work table movement control unit 71 electromagnetically drives the hoisting control valve 61 and the hoisting control valve 62 to raise and lower. The cylinder 22 and the telescopic cylinder 31 are actuated at the same time, and horizontal movement control is performed to horizontally move the work table 40 at an operating direction and an operating speed according to the operating direction and operating amount of the telescopic operating lever 52. Further, the work table movement control unit 71 electromagnetically drives the hoisting control valve 61 and the telescopic control valve 62 when the hoisting operation lever 51 is operated while the horizontal / vertical operation switch 59 is turned on. The cylinder 22 and the telescopic cylinder 31 are operated simultaneously, and vertical movement control is performed to vertically move the work table 40 at an operation direction and operation speed according to the operation direction and operation amount of the hoisting operation lever 51.

  When the operating levers 55 and 56 are operated by the operator M, the traveling control unit 72 electromagnetically drives the control valves 65 and 66 according to the operation command signal, and the second hydraulic pump is supplied to the traveling motor 14 and the steering cylinder 15. Control for supplying hydraulic oil from P2 is performed, and control is performed to drive the traveling body 10 by operating the respective motors 14 and 15 at the operation direction and the operation speed according to the operation direction and operation amount of the operation levers 55 to 56. Configured to do.

  Further, a boom angle detector 81 that detects the boom angle of the boom 30 and a length detector 82 that detects the length of the boom 30 are provided in the boom 30. In the traveling body 10, a turning angle detector 83 that detects a turning angle of the boom 30 (the turning body 20) with respect to the traveling body 10 is provided. Information on the undulation angle, length, and turning angle of the boom 30 detected by the detectors 81 to 83 is input to the position calculation unit 74 of the controller 70.

  The position calculation unit 74 calculates the position of the work table 40 with respect to the traveling body 10 based on the information on the hoisting angle, the length, and the turning angle of the boom 30 input from the detectors 81 to 84, and is the calculation result. The position information of the work table 40 is configured to be output to the work table movement control unit 71. The storage unit 75 stores in advance information on an allowable movement range of the work table 40 (a work range that is set so that the work vehicle 1 can be safely operated without being unstable). Yes. The work table movement control unit 71 compares the position information of the work table 40 calculated by the position calculation unit 74 with the information on the allowable movement range stored in the storage unit 75, and extends the boom 30, for example. When the work table 40 approaches the end of the movement allowable range while moving the movement 40, the movement speed of the work table 40 (extension speed of the boom 30) is reduced, and the work table 40 further reduces the movement allowable range. When it is about to exceed, deceleration / stop control is performed to stop the movement of the work table 40 (extension of the boom 30). Further, the work table movement control unit 71 compares the position information of the work table 40 calculated by the position calculation unit 74 with the information on the allowable movement range stored in the storage unit 75, and for example, raises and lowers the boom 30. When the work table 40 is being moved, if the work table 40 is about to exceed the allowable movement range, the boom 30 is contracted to move the work table 40 so that the work table 40 does not exceed the allowable movement range. It is configured to perform non-stop control.

  The work table movement control unit 71 and the travel control unit 72 perform the movement control of the work table 40 and the travel control of the traveling body 10 as described above, and correspond to the operation amount of the operation levers 51 to 56 and the hoisting cylinder 22. The amount of hydraulic oil supplied to drive each of the telescopic cylinder 31, the turning motor 13, the swinging motor 42, the traveling motor 14, and the steering cylinder 15 (hereinafter collectively referred to as "actuator AC"). It is configured to control the rotational speed of the engine E that drives the first and second hydraulic pumps P1 and P2 so as to be secured. Hereinafter, control of the rotation speed of the engine E will be described.

  First, the storage unit 75 stores in advance information on the supply amount of hydraulic oil necessary to drive each of the actuators AC in accordance with the operation amounts of the operation levers 51 to 56. Further, in the storage unit 75, the rotation speed (throttle opening) of the engine E with respect to the total supply amount of hydraulic oil is ensured so that the total supply amount of hydraulic oil necessary for driving the actuators AC can be secured. Is stored in advance. Note that the amount of hydraulic oil actually supplied to the actuator (total supply amount) is determined by the operation of the control valve in accordance with the operation of the operation lever. At this time, since the actuator cannot perform a desired operation if the amount of hydraulic oil (pump discharge amount) supplied to the control valve is insufficient, the pump discharge amount is determined by the amount of hydraulic oil supplied to the actuator by the control valve ( A discharge amount larger than the total supply amount) is required. For this reason, the engine speed is set so as to have a margin so that a pump discharge amount somewhat larger than the total supply amount can be obtained so that the necessary total supply amount can be secured. However, if the pump discharge amount becomes excessively large, energy loss occurs. Therefore, the engine speed is set so that a pump discharge amount having a slight margin with respect to the required total supply amount can be obtained.

The storage unit 75 stores two control maps, a normal operation control map M1 and an automatic operation control map M2, as information on the rotational speed of the engine E with respect to the total supply amount of hydraulic oil. As shown in FIG. 3, in the normal operation control map M1, the engine speed becomes the idling speed when the total supply amount of hydraulic oil is zero, and the engine speed becomes stepless (linear) as the total supply amount increases. To a proportional relationship that increases. On the other hand, in the automatic operation control map M2, as shown in FIG. 4, when the total supply amount of hydraulic oil is zero, the engine rotation speed becomes the idling rotation speed, and the engine rotation speed increases in five stages as the total supply volume increases. It is set to be large. That is, when the total supply amount is from zero to less than S ₁ , the engine speed is set to the idling rotation number, and when the total supply amount is greater than or equal to S ₁ and less than S ₂ , the engine speed is constant R ₁ ( is set to R _1> idling speed), the total supply amount is set to R ₂ engine speed is constant rotational speed when less than _{S 3 (R 2> R 1} ) in S ₂ or more, the total supply amount S ₃ or S-engine speed is constant rotational speed when less than _{4 R 3 (R 3> R} 2) is set to a total supply amount S ₄ than the maximum rotational speed is the engine speed when the (maximum Rotational speed> R ₃ ). As described above, in the automatic operation control map M2, the engine speed corresponding to the total supply amount belonging to one of the groups is set in five stages by grouping the total supply amount.

The work table movement control unit 71 and the travel control unit 72 read the supply amount of hydraulic oil supplied to each of the actuators AC according to the operation amount of the operation levers 51 to 56 from the storage unit 75, and supply those read out The total amount (total supply amount) is calculated. For example, let x ₁ , x ₂ , and x ₃ be the supply amounts of hydraulic oil required to drive the hoisting cylinder 22, the telescopic cylinder 31, and the swing motor 13 in accordance with the operation amounts of the operation levers 51 to 53. The total supply amount X is calculated as X = x ₁ + x ₂ + x ₃ . Then, the work table movement control unit 71 and the travel control unit 72 use the normal operation control map M1 or the automatic operation control map stored in the storage unit 75 for the engine speed corresponding to the calculated total supply amount X of hydraulic oil. It reads from M2, and it is comprised so that the rotation speed of the engine E may be controlled via the engine control part 73 so that it may become the read engine rotation speed.

  In the work table movement control unit 71 and the travel control unit 72, the work table movement control unit 71 determines which of the normal operation control map M1 and the automatic operation control map M2 is used to control the rotational speed of the engine E. It is determined by whether or not the movement control of the work table 40 is based on automatic operation control. This automatic operation control means that the boom 30 and the like are automatically controlled by performing hydraulic oil supply control without corresponding to the operation of the operation lever, such as the above-described horizontal / vertical movement control, deceleration / stop control, and non-stop control. It is the control to operate.

  The work table movement control unit 71 and the travel control unit 72 are operated by operating the operation levers 51 to 56, respectively, and operate the actuator AC with the operation direction and the operation speed according to the operation direction and the operation amount, respectively. When the normal operation control for moving the vehicle or traveling the traveling body 10 is performed, the total supply amount of necessary hydraulic oil is calculated as described above according to the operation amount of the operated operation lever, and the calculation is performed. The engine rotational speed corresponding to the total supply amount of hydraulic oil is obtained using the normal operation control map M1, and control is performed to change the rotational speed of the engine E steplessly (linearly) via the engine control unit 73. Has been. That is, when operating the operating table 40 by moving any one of the actuators AC according to the respective operations of the operation levers 51 to 56 or moving the traveling body 10, the normal operation control map M1 is used. Thus, control is performed to change the rotational speed of the engine E steplessly (linearly).

  On the other hand, the work table movement control unit 71 operates the telescopic operation lever 52 or the hoisting operation lever 51 in a state where the horizontal / vertical operation switch 59 is turned on, and the operation direction corresponding to the operation direction and the operation amount. In the case of performing horizontal / vertical movement control in which the hoisting cylinder 22 and the telescopic cylinder 31 are simultaneously operated at the operating speed to perform horizontal movement or vertical movement of the work table 40, according to the operation amount of the telescopic operation lever 52 or the hoisting operation lever 51. Thus, the total supply amount of hydraulic oil necessary for operating the hoisting cylinder 22 and the telescopic cylinder 31 in the horizontal / vertical movement control is calculated. Then, the engine rotational speed corresponding to the calculated total supply amount of hydraulic oil is obtained using the automatic operation control map M2, and control is performed to change the rotational speed of the engine E in multiple stages via the engine control unit 73. It is configured.

  In addition, the work table movement control unit 71 calculates the total supply amount of hydraulic oil necessary for the deceleration / stop control or non-stop control even when performing the above-described deceleration / stop control and non-stop control, and calculates the calculated operation The engine rotational speed corresponding to the total supply amount of oil is obtained using the automatic operation control map M2, and control is performed to change the rotational speed of the engine E in multiple stages via the engine control unit 73. That is, the work table movement control unit 71 performs hydraulic oil supply control without corresponding to the operation of the operation lever as in the above-described horizontal / vertical operation control, deceleration / stop control, and non-stop control, and performs a plurality of actuator operations. Are operated simultaneously, or when the automatic operation control for moving the work table 40 by changing the operation speed of the actuator is performed, the control for changing the rotational speed of the engine E in multiple stages is performed using the automatic operation control map M2. Configured to do.

  Further, the work table movement control unit 71 performs the normal operation control map M1 for a predetermined time from the start of the automatic operation control in the automatic operation control such as the above-described horizontal / vertical operation control, deceleration / stop control, and non-stop control. Is used to change the rotational speed of the engine E steplessly, and after the predetermined time has elapsed, the automatic operation control map M2 is used instead of the normal operation control map M1, and the rotational speed of the engine E is multistaged. It is comprised so that the control which changes may be performed. In addition, the work table movement control unit 71 performs control to change the rotation speed of the engine E steplessly using a normal operation control map M1 instead of the automatic operation control map M2 for a predetermined time immediately before the stop of the automatic operation control. It is configured as follows.

  In addition, the work table movement control unit 71 uses the automatic operation control map M2 to change the engine speed in multiple stages. As shown by the chain line A, it can be changed and controlled. In addition, the work table movement control unit 71 and the travel control unit 72 are configured so that the operation levers 51 to 56 are returned to the neutral position, and the operation stop operation of the work table 40 or the travel stop operation of the traveling body 10 is performed. Rather than immediately reducing the rotational speed of E to the idling rotational speed, the engine rotational speed is controlled to gradually decrease to the idling rotational speed over a predetermined time.

  Further, the controller 70 restricts the control of changing the rotational speed of the engine E via the engine control unit 73 by the work table movement control unit 71 when the travel control unit 72 performs the travel operation control to travel the traveling body 10. Thus, priority is given to control for changing the rotational speed of the engine E via the engine control unit 73 by the travel operation control unit 72 in accordance with the operation of the travel operation lever 55 and the steering operation lever 56.

In the aerial work vehicle 1 configured as described above, for example, as shown in FIG. 5, the horizontal / vertical operation switch 59 is turned on and the telescopic operation lever 52 is tilted to the maximum at time t ₁ . When the operation is performed (the operation input is set to 100%) and the horizontal movement control for horizontally moving the work table 40 is started, the work table movement control unit 71 performs, for example, the hoisting cylinder 22 and the telescopic cylinder from time t ₁ to t _2. Until the operation speed of 31 reaches the target speed corresponding to the operation input 100%, the normal operation control map M1 shown in FIG. 3 is used to perform control to change the rotation speed of the engine E steplessly (linearly). . Then, the total supply amount (required flow rate) of hydraulic oil supplied to the hoisting cylinder 22 and the telescopic cylinder 31 and the rotational speed of the engine E rise as shown in FIG. 5, and the operating speeds of the hoisting cylinder 22 and the telescopic cylinder 31 are increased. The target speed corresponds to 100% of the operation input, and the hoisting cylinder 22 and the telescopic cylinder 31 are operated. The worktable movement control unit 71, the operating speed of the time t ₂ becomes derricking cylinder 22 and telescopic cylinder 31 becomes equal to the target speed, automatic operation control shown in FIG. 4 in place of the normal operation control map M1 which has been used until then Control for changing the rotational speed of the engine E in multiple stages is performed by the map M2. Then, the total supply amount of hydraulic oil and the rotational speed of the engine E rise as shown in FIG. 5, and the rotational speed of the engine E becomes the maximum rotational speed corresponding to the operation input 100%.

Then, between when 50% of the operation input performed an operation for returning the operation amount of the telescopic operation lever 52 a half at time t _3, the worktable movement control unit 71, from the time t ₃ to t _4, for example derricking cylinder 22 Until the operating speed of the telescopic cylinder 31 reaches the target speed corresponding to the operation input of 50%, the normal operation control map M1 is used instead of the automatic operation control map M2 used so far, and the rotational speed of the engine E is used. Control to change the steplessly. Then, the total amount of hydraulic oil supplied to the hoisting cylinder 22 and the telescopic cylinder 31 and the rotational speed of the engine E are reduced as shown in FIG. 5, and the operating speed of the hoisting cylinder 22 and the telescopic cylinder 31 is 50% of the operation input. The undulation cylinder 22 and the telescopic cylinder 31 are operated. Then, the work table movement control unit 71, the operating speed of the time t ₄ becomes derricking cylinder 22 and telescopic cylinder 31 becomes equal to the target speed, the automatic operation control map M2 in place of the normal operation control map M1 which has been used until then engine Control is performed to change the rotation speed of E in multiple stages. If it does so, the total supply amount of hydraulic fluid and the rotation speed of the engine E will decrease as shown in FIG. 5, and the rotation speed of the engine E will become a rotation speed corresponding to 50% of operation inputs.

Further, when the operation input is set to 0% by performing the operation of returning the telescopic operation lever 52 to the neutral position at time t ₅ and the horizontal movement control of the work table 40 is stopped, the work table movement control unit 71 starts from time t _5. Until t ₆ , for example, until the operating speeds of the hoisting cylinder 22 and the telescopic cylinder 31 become zero, the normal operation control map M 1 is used instead of the automatic operation control map M 2 used so far, and the engine E Control to change the rotation speed steplessly. Then, the total supply amount of hydraulic oil and the rotational speed of the engine E decrease as shown in FIG. 5, and the rotational speed of the engine E becomes an idling rotational speed corresponding to 0% of the operation input. When thus operated to stop the horizontal movement control of the work table 40 is performed, instead of lowering the idling speed immediately the speed of the engine E, t and engine speed from a predetermined time (time t _{5 6} ) until the idling speed is gradually reduced.

  In addition, the work table movement control unit 71 performs control to change the engine speed steplessly using the normal operation control map M1 according to the operation of any of the operation levers 51 to 54, and In the state where the control for operating the actuator AC is performed, when the other operating levers of the operating levers 51 to 54 are operated to operate the other actuators AC (two or more actuators are linked), The flow rate of hydraulic oil supplied to the actuator AC is limited, and control is performed to ensure the flow rate of hydraulic oil supplied to another actuator AC (actuator AC to be operated) to operate the other actuator AC. To control. And it is comprised so that the rotation speed of the engine E may be controlled to hold | maintain at the engine speed before operating other actuator AC, without changing.

For example, as shown in FIG. 6, at time t ₁ ′, the operation of tilting the telescopic operation lever 52 to the maximum is performed (the operation input is 100%), and the telescopic cylinder 31 is expanded and contracted to move the work table 40. When the control is started, the work table movement control unit 71 changes the rotation speed of the engine E steplessly using the normal operation control map M1 shown in FIG. 3 according to the operation input 100% of the telescopic operation lever 52. Take control. Then, the supply amount (required flow rate) of the hydraulic oil supplied to the expansion / contraction cylinder 31 and the rotational speed of the engine E increase as shown in FIG. 6, and the operation speed of the expansion / contraction cylinder 31 corresponds to the target speed corresponding to 100% of the operation input. Thus, the telescopic cylinder 31 operates.

Then, at time t ₂ ′, the undulation operation lever 51 is gradually tilted to the maximum extent (over a predetermined time until time t ₃ ′), and the undulation cylinder 22 is also undulated to move the work table 40. When the control is started, the work table movement control unit 71 performs control to restrict the supply amount of the hydraulic oil supplied to the telescopic cylinder 31 and secure the supply amount of the hydraulic oil supplied to the hoisting cylinder 22. Further, the work table movement control unit 71 performs control (control as indicated by a one-dot chain line in FIG. 6) to reduce the rotational speed of the engine E in response to limiting the amount of hydraulic oil supplied to the telescopic cylinder 31. Instead, control is performed to maintain the engine speed before operating the hoisting cylinder 22. As a result, the total amount of hydraulic oil supplied to the telescopic cylinder 31 and the hoisting cylinder 22 decreases at the start of operation of the hoisting operation lever 51 as shown in FIG. Rises accordingly. Then, the operating speed of the telescopic cylinder 31 becomes a target speed corresponding to the amount of hydraulic oil supplied, and the telescopic cylinder 31 operates. Further, the operating speed of the hoisting cylinder 22 becomes a target speed corresponding to the operation input 100%, and the hoisting cylinder 22 is operated.

  In the example of FIG. 6, the case where the operation of gradually tilting the hoisting operation lever 51 is shown, but even when the operation of tilting the hoisting operation lever 51 at once is performed, Control to maintain the engine speed before operating the hoisting cylinder 22 is performed. In FIG. 6, the amount of hydraulic oil supplied is limited so that the operating speed of the telescopic cylinder 31 is about 50%. However, this is an example, and how much the hydraulic oil is limited depends on the interlocking of the actuator and the like. The setting can be changed as appropriate in consideration. Further, the amount that limits the operating speed (extension output) of the telescopic cylinder 31 is a variable amount that changes according to the operation input amount of the hoisting operation lever 51, and the hoisting cylinder 22 is limited by the amount that the operating speed of the telescopic cylinder 31 is limited. It is good also as a structure which controls so that the operating speed (undulation output) of this may increase. Even with this configuration, the engine speed can be maintained.

  Thus, in the aerial work vehicle 1, the work table movement control unit 71 performs the normal operation control shown in FIG. 3 in the automatic operation control such as the horizontal / vertical operation control, the deceleration / stop control, and the non-stop control described above. Instead of the control for changing the rotation speed of the engine E steplessly using the map M1, the automatic operation control map M2 shown in FIG. 4 is used to perform the control for changing the rotation speed of the engine E in multiple steps. Has been. Therefore, in the automatic operation control of the work device, it is possible to suppress the frequency at which the engine speed changes, compared to the conventional configuration in which the engine speed is changed by stepless control. Therefore, it is possible to prevent the worker from feeling uncomfortable or being mistaken for a failure.

  Further, in the automatic operation control such as the horizontal / vertical operation control, the deceleration / stop control, and the non-stop control described above, the work table movement control unit 71 performs the normal operation control map M1 for a predetermined time from the start of the automatic operation control. Is used to change the rotational speed of the engine E steplessly, and after the predetermined time has elapsed, the automatic operation control map M2 is used instead of the normal operation control map M1, and the rotational speed of the engine E is multistaged. It is comprised so that the control which changes may be performed. Further, the work table movement control unit 71 performs control to change the rotation speed of the engine E steplessly using a normal operation control map M1 instead of the automatic operation control map M2 for a predetermined time immediately before the stop of the automatic operation control. It is configured as follows. When the operation is started and stopped by the automatic operation control, the change range of the engine speed increases. When control is performed to change the engine speed in multiple stages using the automatic operation control map M2 at the time of starting and stopping the operation, the engine speed changes in multiple stages in a short time, and an unpleasant engine drive sound. It may become. Therefore, according to the above configuration, when the change width of the engine speed increases at the start and stop of the automatic operation control, the engine E is continuously changed using the normal operation control map M1. By performing the control, the engine speed is changed continuously (smoothly), so that the driving sound of the engine can be prevented from becoming an annoying sound.

  In addition, in the control in which the work table movement control unit 71 changes the engine speed in multiple stages using the automatic operation control map M2, the rate of change when the engine speed of the engine E is changed is shown in FIG. It is configured to be able to perform control as shown in FIG. Therefore, the change in the engine speed in the multi-stage control can be smoothed, and the change in engine driving sound can be smoothed.

  Further, when the operation levers 51 to 54 are returned to the neutral position and the operation stop operation of the work table 40 is performed, the work table movement control unit 71 immediately reduces the rotation speed of the engine E to the idling rotation speed. Instead, the engine speed is controlled to gradually decrease to the idling speed over a predetermined time. The allowable torque of the engine also changes at the same time due to the change in the engine speed when the operation of the work device is stopped. Therefore, according to the above configuration, even when the engine has a small allowable torque at the idling speed, it is possible to prevent the engine from stalling when the operation apparatus is stopped.

  Further, when the travel control of the controller 70 is performed by the travel controller 72 so that the traveling body 10 travels, the control of changing the rotational speed of the engine E via the engine controller 73 by the worktable movement controller 71 is restricted. Thus, priority is given to control for changing the rotational speed of the engine E via the engine control unit 73 by the travel operation control unit 72 in accordance with the operation of the travel operation lever 55 and the steering operation lever 56. For this reason, for example, when an attempt is made to operate the work device while traveling, it is possible to prevent a situation in which the engine speed increases due to the work operation and the traveling speed increases due to the increase in the engine speed. Can do.

  Further, when the work table movement control unit 71 operates the other actuator AC, the flow rate of the hydraulic oil supplied to the operating actuator AC is limited, and the other actuator AC (the actuator to be operated) AC) is performed to control the flow rate of the hydraulic oil supplied to the other actuator AC, and the engine E is kept at the engine speed before the other actuator AC is operated without changing the engine E speed. It is configured to perform control. In the conventional control, control for reducing the engine speed is performed in response to limiting the amount of hydraulic oil supplied to the operating actuator. Therefore, an operation for operating another actuator is performed and an operation input is performed. Despite the increase, the engine speed decreased, causing the operator to feel uncomfortable. However, according to the above configuration, the engine speed is maintained even if the amount of hydraulic oil supplied to the operating actuator is limited, so that it is possible to prevent the operator from feeling uncomfortable as described above.

  Although the embodiment according to the present invention has been described so far, the scope of the present invention is not limited to that shown in the above-described embodiment. For example, in the above-described embodiment, when the movement stop operation of the work table 40 is performed, the engine E is configured to perform control to gradually reduce the engine speed to the idling speed over a predetermined time. However, when the movement stop operation of the work table 40 is performed, control is performed so that the rotation speed is decreased to a predetermined rotation speed larger than the idling rotation speed, held at the predetermined rotation speed for a predetermined time, and then decreased to the idling rotation speed. You may comprise. Even if comprised in this way, it can prevent that an engine stalls at the time of operation stop of a working device similarly to the said structure.

  In the above-described embodiment, as shown in FIG. 4, as an automatic operation control map M2, an example is shown in which the engine speed with respect to the total supply amount of hydraulic oil is set in five stages. However, the present invention is not limited to this. Instead, it may be set to any of 2, 3, 4, and 6 or more stages. In the above-described embodiment, the hydraulic drive mechanism that supplies hydraulic oil to the actuator is configured by an HST hydraulic closed circuit including a hydrostatic transmission (HST), and is a variable displacement hydraulic pump or variable displacement driven by an engine. The capacity may be controlled by changing the swash plate angle of the hydraulic motor. In the above-described embodiment, the self-propelled aerial work vehicle 1 has been described as an example of a working vehicle including the control device according to the present invention. However, the control device according to the present invention is, for example, a truck vehicle. The present invention can also be applied to various work vehicles such as an aerial work vehicle based on the above.

DESCRIPTION OF SYMBOLS 1 Aerial work vehicle 10 Traveling body 14 Traveling motor (traveling device)
30 Boom (Working device)
40 Working table (working equipment)
50 Operation box 51 Relief operation lever (work operation means)
52 Telescopic operation lever (work operation means)
53 Swing operation lever (work operation means)
55 Travel control lever (travel control means)
59 Horizontal / vertical operation switch 70 Controller 71 Work table movement control section (work control means)
72 Travel control unit (travel control means)
73 Engine control unit E Engine P1 First hydraulic pump (working pump)
P2 Second hydraulic pump (traveling pump)

Claims (8)

Control of a working vehicle comprising: a traveling body; a working device that receives a supply of hydraulic oil to perform a predetermined work; a working pump that supplies the working device with hydraulic oil; and an engine that drives the working pump. A device,
Work operation means for operating the work device;
Proportional supply control for supplying hydraulic oil from the work pump to the work device in accordance with the operation of the work operation means, and stepless control for continuously changing the engine speed. And a work control means for operating the work device,
The work control means is configured to automatically control the operation of the work device by performing automatic supply control for supplying hydraulic oil different from the proportional supply control under a predetermined condition, In automatic operation control, the engine speed is controlled by multistage control that changes the engine speed in multiple stages instead of the stepless control.   In the automatic operation control, the work control means controls the engine speed by the stepless control for a predetermined time from the start of the automatic operation control, and the stepless control after the predetermined time has elapsed. 2. The work vehicle control device according to claim 1, wherein the engine speed is controlled by the multi-stage control.   In the automatic operation control, the work control means controls the engine speed by the stepless control instead of the multistep control for a predetermined time immediately before the stop of the automatic operation control. The control device for a working vehicle according to claim 1 or 2.   The said work control means is comprised so that a change rate when changing the rotation speed of the said engine in the said multistage control can be changed, and the said multistage control can be performed. The control apparatus of the working vehicle in any one.   The work control means performs control to gradually lower the engine speed to an idling speed over a predetermined time when an operation stop operation of the work device is performed by the work operation means. The control device for a working vehicle according to any one of claims 1 to 4.   The work control means holds the engine speed at a predetermined speed greater than the idling speed for a predetermined time when the operation stop operation of the work device is performed by the work operation means, and thereafter The control device for a working vehicle according to any one of claims 1 to 4, wherein control is performed to reduce the idling speed. The traveling body has a traveling device that travels by receiving supply of hydraulic oil,
A traveling pump for supplying hydraulic oil to the traveling device;
The engine is configured to drive the working pump and the traveling pump,
Traveling operation means for operating the traveling device;
In accordance with the operation of the travel operation means, control is performed to supply hydraulic oil from the travel pump to the travel device, and control is performed to change the engine speed, thereby operating the travel device. Traveling control means for causing
When the operation control of the traveling device is performed by the traveling control unit, the control for changing the engine speed is regulated by the work control unit, and the engine speed is changed according to the operation of the traveling operation unit. 7. The work vehicle control apparatus according to claim 1, wherein priority is given to the control of the travel control means. The work control means performs the proportional supply control of hydraulic oil and the stepless control of the engine speed to operate other actuators in the work device in a state where a predetermined actuator in the work device is operated. When operating, the flow rate of hydraulic oil supplied to the predetermined actuator is limited to perform control to ensure the flow rate of hydraulic oil supplied to the other actuator to operate the other actuator, and The control device for a working vehicle according to any one of claims 1 to 7, wherein control is performed to maintain the rotational speed before operating the other actuator without changing the rotational speed of the engine.

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