KR100680928B1 - Prime mover controller of construction machine - Google Patents

Abstract

 According to the present invention, the hydraulic pump 24 driven by the prime mover 10, the actuator 5 driven by the hydraulic oil discharged from the hydraulic pump 24, and the first hydraulic member 22a are operated. In the prime mover control device of a construction machine having a control valve 25 for controlling the flow of pressure oil from the pump 24 to the actuator 5, the first of the prime mover 10 in accordance with the operation of the first operating member 22a. First setting means 41 for setting the set speed Nt, second setting means 43 for setting the second set speed Nx of the prime mover 10 in accordance with the operation of the second operating member 34, When the first member is selected by the selection member 35 that selects the first mode or the second mode, and the first member is selected by the selection member 35, the prime mover is set to a larger value between the first set rotational speed Nt and the second set rotational speed Nx. If the second mode is selected by the selection member 35, the motor speed is controlled by the second set speed Nx. It includes a speed control means (30, 13).

Prime mover, hydraulic pump, actuator, selection member, setting means.

Description

Mover control device for construction machinery {PRIME MOVER CONTROLLER OF CONSTRUCTION MACHINE}

 The present invention relates to a prime mover control device for a construction machine that can change the prime mover rotation speed in accordance with the operation amount.

 Conventionally, what is disclosed in Japanese Patent No. 2634330 is known as a control device of this kind.

In the apparatus described in this publication, the rotation speed according to the operation amount of the rotation speed setting device (fuel lever) and the rotation speed according to the operation amount of the traveling pedal are set, respectively, and the larger value is selected as the target rotation speed. As a result, the lower limit value of the target rotational speed is limited to the rotational speed according to the operation amount of the rotational speed setter. Therefore, if the set rotational speed is set to a value suitable for work (excavation, etc.) by the rotational speed setter, the engine speed Can be reduced, and workability is good. In addition, if the set rotation speed of the rotation speed setter is set to the idle rotation speed at the time of traveling, since the prime mover rotation speed changes according to the operation amount of the traveling pedal, it is possible to achieve fuel efficiency and noise reduction.

In the apparatus described in the above publication, in order to adjust the vehicle travel speed by adjusting the operation amount of the travel pedal, for example, when the vehicle is traveling at a constant speed, it is necessary to maintain the travel pedal at a predetermined half pedal position. have. However, it is a burden for a driver to keep a fixed speed running state by the half pedal.

 An object of the present invention is to provide a prime mover control device for a construction machine that is easy to adjust speed.

The present invention has a hydraulic pump driven by a prime mover, an actuator driven by pressure oil discharged from the hydraulic pump, and a control valve for controlling the flow of pressure oil from the hydraulic pump to the actuator in accordance with the operation of the first operating member. Applied to construction machinery. The prime mover control device includes first setting means for setting the first set rotational speed of the prime mover in accordance with the operation of the first operating member, and a second setting rotation speed for the prime mover in accordance with the operation of the second operating member. 2 setting means, the selection member which selects a 1st mode or a 2nd mode, and when a 1st mode is selected by a selection member, the prime mover rotation speed is set to the larger value of a 1st set rotation speed and a 2nd set rotation speed. And rotation speed control means for controlling the prime mover speed at the second set rotation speed when the second mode is selected by the selection member.

Moreover, the prime mover control apparatus of the construction machine which concerns on this invention is the 1st setting means which sets the 1st set rotation speed of a prime mover according to operation of a 1st operating member, and 2nd setting of a prime mover according to operation of a 2nd operating member. The second setting means for setting the rotation speed, the selection member for selecting the first mode or the second mode, and the prime mover rotation speed at the first set rotation speed when the first mode is selected by the selection member, And rotational speed control means for controlling the prime mover speed at the second set rotation speed when the second mode is selected.

Accordingly, in the second mode, the driving speed of the actuator can be changed in accordance with the operation amount of the second operating member in the state where the first operating member is operated at the maximum, and the speed of the actuator can be easily adjusted.

It is preferable to make a 1st operation member and a 2nd operation member into a pedal type operation member and a manual operation member, respectively.

It is preferable to provide the selection member in the vicinity of the second operation member. The actuator may be a travel motor.

It is judged whether it is a running state or a working state, and when a running state is determined, a 1st set rotation speed can be set to a larger value than when a working state is detected. In this case, when the brake non-operation and the neutral operation are detected, it can be determined as the running state.

It is preferable to apply this invention to a wheel type hydraulic excavator.

1 is a view showing the appearance of a wheel-type hydraulic excavator to which the present invention is applied.

2 is a hydraulic circuit diagram for driving the wheel-type hydraulic excavator of FIG. 1.

3 is a hydraulic circuit diagram for the work of the wheel-type hydraulic shovel of FIG.

4 is a block diagram of a prime mover control device according to an embodiment of the present invention.

5 is a diagram illustrating details of a control circuit of FIG. 4.

6 is a flowchart illustrating a control procedure of the engine speed.

7 is a diagram illustrating an example of a setting dial and a changeover switch arrangement.

8 is a diagram illustrating a modification of FIG. 5.

Hereinafter, an embodiment in which the prime mover control device according to the present invention is applied to a wheel type hydraulic excavator will be described with reference to FIGS. 1 to 6.

As shown in FIG. 1, the wheel type hydraulic excavator has a traveling body 1 and a swinging body 2 rotatably mounted on the upper side of the traveling body 1. The swinging structure 2 is provided with the work front attachment 4 which consists of the cab 3, the boom 4a, the arm 4b, and the bucket 4c. The boom 4a is undulated by the drive of the boom cylinder 4d, the arm 4b is undulated by the drive of the arm cylinder 4e, and the bucket 4c is driven by the drive of the bucket cylinder 4f. By cloud or by dump. The traveling body 1 is provided with the traveling motor 5 by hydraulic drive, and the rotation of the traveling motor 5 is transmitted to the wheel 6 (tire) via a propeller shaft and an axle.

FIG. 2 is a hydraulic circuit diagram for driving the wheel type hydraulic excavator shown in FIG. 1. FIG. The hydraulic circuit includes the main pump 24 driven by the prime mover 10, the travel motor 5 driven by the hydraulic oil from the main pump 24, and the main pump 24 from the main pump 24 to the travel motor 5. Advance by operation of the control valve 25 which controls the flow of hydraulic oil, the pilot pump 21, the pilot valve 22 driven by the pedal-type traveling pedal 22a, and the forward / backward switching switch which is not shown in figure. And a forward and backward conversion valve 23 converted to a position, a reverse position, and a neutral position.

When the forward / backward switching valve 23 is switched to the forward position or the backward position by the switch operation, and the traveling pedal 22a is operated, the pilot pressure from the pilot pump 2l acts on the control valve 25. As a result, the hydraulic oil from the main pump 24 is supplied to the travel motor 5 through the control valve 25, and the vehicle can be advanced or retracted by the rotation of the travel motor 5. The pressure sensor 31 is connected to the pilot valve 22, and the pilot pressure Pt as the travel command is detected by the pressure sensor 31.

As an example of a working hydraulic circuit, the hydraulic circuit of a boom cylinder is shown in FIG. This hydraulic circuit controls the flow of the hydraulic oil from the main pump 26, the boom cylinder 4d which is expanded and contracted by the hydraulic oil from the main pump 26, and the boom cylinder 4d from the main pump 26. The control valve 27, the pilot pump 21, and the pilot valve 28 driven by the operation lever 28a are provided. Although not shown, the hydraulic circuits of the other actuators for driving the front attachment are also the same.

When the operation lever 28a is operated, the pilot valve 28 is driven according to the operation amount, and the pilot pressure from the pilot pump 21 acts on the control valve 27. As a result, the hydraulic oil from the main pump 26 is led to the boom cylinder 4d through the control valve 27, and the boom 4a is lifted by the expansion and contraction of the boom cylinder 4d. The main pump 26 may be omitted, and the cylinder 4d may be driven by the hydraulic oil from the main pump 24 shown in FIG. 2.

In this embodiment, the engine speed is controlled by the pedal mode (first mode) or dial mode (second mode) described later to adjust the pump discharge amount and to adjust the speed of the vehicle.

4 is a block diagram of a control circuit for controlling the rotation speed of the engine. The governor lever 11 of the engine 10 is connected to the pulse motor 13 via the link mechanism 12, and the engine speed is changed by the rotation of the pulse motor 13. In other words, the engine speed increases due to the electrostatic discharge of the pulse motor 13, and decreases in reverse. A potentiometer 14 is connected to the governor lever 11 via the link mechanism 12, and the potentiometer 14 detects the governor lever angle according to the rotation speed of the engine 10, and rotates the engine control. It is input to the control circuit 30 as the number Nθ.

The control circuit 30 includes a pressure sensor 31 that detects a pilot pressure Pt according to the amount of operation of the travel pedal 22a, a position switch that detects a switching position of the brake switch 32 and the forward and backward conversion valve 23. (33), a manual setting dial 34 which outputs a signal corresponding to the dial operation amount X and instructs the engine speed, and a conversion switch 35 which selectively switches the pedal mode and the dial mode are connected.

The brake switch 32 is converted into driving, working and parking positions to output work / driving signals. When the vehicle is switched to the driving position, the parking brake is released, and the brake pedal allows the operation of the service brake. When shifted to the working position, activate the parking brake and service brake. When the vehicle is switched to the parking position, the parking brake is activated. The brake switch 32 outputs an off signal when converted to the travel position, and outputs an on signal when converted to the work and parking position.

The setting dial 34 is provided in an operation panel near the driver's seat so as to be operable at the time of driving. The changeover switch 35 is provided adjacent to the setting dial 34 to enable operation without releasing the hand from the setting dial 34. An example of the arrangement of the setting dial 34 and the conversion switch 35 is shown in FIG.

The rotation speed control circuit 30 performs the following calculation and outputs a control signal to the pulse motor 13.

5 is a conceptual diagram illustrating the details of the rotation speed control circuit 30. As shown in the figure, the relationship between the detected value Pt by the pressure sensor 3l and the target rotational speeds Nt, Nd is stored in advance in the rotational speed calculating sections 41 and 42, respectively. The target rotational speeds Nt and Nd are respectively calculated. In addition, the characteristic of the rotation speed calculating part 41 is a characteristic suitable for running, and the characteristic of the target rotation speed calculating part 42 is a characteristic suitable when carrying out work using the attachment 4 for work. According to these characteristics, the target rotation speeds Nt and Nd increase linearly from the idle rotation speed Ni as the pedal operation amount increases. The increase inclination of the target rotational speed Nt is greater than the increase inclination of the target rotational speed Nd, and the maximum value Ntmax of the target rotational speed Nt is larger than the maximum value Ndmax of the target rotational speed Nd.

As shown in the figure, the relationship between the manipulation amount X of the setting dial 34 and the target rotation speed (setting rotation speed) Nx is stored in advance in the rotation speed calculating section 43, and from this characteristic, the target rotation speed Nx according to the dial manipulation amount X is calculated. Calculate The maximum value Nxmax of the target rotational speed Nx is set equal to the maximum value Ndmax of the rotational speed calculating section 42 (Nxmax = Ndmax).

The selector 44 selects any one of target rotational speeds Nt and Nd of the rotational speed calculating sections 41 and 42 in accordance with signals from the brake switch 32, the position sensor 33 and the pressure sensor 31. In this case, the brake switch 32 is switched to the travel position (off signal output), the forward and backward conversion valve 23 is outside the neutral position, and the pilot pressure Pt by the operation of the travel pedal 22a is a predetermined value. In the above case, that is, the target rotational speed Nt is selected at the time of running, and in other conditions, that is, the target rotational speed Nd is selected at the time of non-driving.

The maximum value selector 45 selects, as Nmax, the larger value of the target rotational speed Nt or Nd selected by the selection unit 44 and the target rotational speed Nx calculated by the rotational speed calculator 43.

The mode conversion unit 46 selects either the target rotational speed Nmax selected by the maximum value selecting section 45 or the target rotational speed Nx calculated by the rotational speed calculating section 43 according to the signal from the conversion switch 35. . In this case, the target rotational speed Nmax is selected when the changeover switch 35 is switched to the pedal mode, and the target rotational speed Nx is selected when the conversion switch 35 is switched to the dial mode.

The servo controller 47 compares the rotation speed (rotation command value Nin) selected by the mode converter 46 with the control rotation speed Nθ corresponding to the displacement amount of the governor lever 11 detected by the potentiometer 14. do. And the pulse motor 13 is controlled so that both may correspond according to the procedure shown in FIG.

In FIG. 6, the rotation speed command value Nin and the control rotation speed N (theta) are respectively read in step S21, and it progresses to step S22. In step S22, the result of N (theta) -Nin is stored in memory as rotation speed difference A, and it is determined in step S23 whether | A | ≥K using the predetermined reference speed difference K. If affirmative, the process proceeds to step S24, and it is determined whether the rotation speed difference A> 0, and if A> 0, the engine rotation because the control rotation speed Nθ is larger than the rotation speed command value Nin, that is, the control rotation speed is higher than the target rotation speed. In order to lower the number, a signal for commanding motor reversal is output to the pulse motor 13 in step S25. As a result, the pulse motor 13 is reversed to lower the engine speed.

On the other hand, when A? 0, since the control rotation speed Nθ is smaller than the rotation speed command value Nin, that is, the control rotation speed is lower than the target rotation speed, a signal for commanding the motor power failure is output in step S26 to increase the engine speed. As a result, the pulse motor 13 is out of power and the engine speed is increased. If step S23 is negative, the process proceeds to step S27 to output a motor stop signal, whereby the engine speed is maintained at a constant value. Execution of steps S25 to S27 returns to the start.

Next, the characteristic operation of the prime mover control device which concerns on a present Example is demonstrated.

(1) pedal mode

First, the case where the pedal mode is selected by the changeover switch 35 will be described. With the pedal mode, it is possible to set the engine speed by the operation of the travel pedal 22a. For example, the pedal mode is suitable for normal driving that generates maximum torque during driving.

At the time of traveling, the brake switch 32 is operated to a traveling position, the forward / backward switching switch is operated to the forward position or the reverse position, and the setting dial 34 is operated to the idle position. When the traveling pedal 22a is operated in this state, the control valve 25 is switched in accordance with the operation amount, and the traveling motor 5 is rotated by the oil pressure from the main pump 24.

At this time, the target rotational speed Nt is selected by the selector 44 by the calculation in the control circuit 30, and the target rotational speed Nt is also selected by the maximum value selector 45. Thereby, target rotation speed Nt is set as rotation speed command value Nin, and engine speed is controlled by target rotation speed Nt by the signal output to the pulse motor 13 by servo control. In this case, the engine speed is changed according to the characteristics of the speed calculating part 41 suitable for travel. Therefore, good acceleration can be obtained, and fuel efficiency and noise can be reduced.

When performing work (excavation, etc.) in a vehicle stop state, the brake switch 32 is operated to a working position, and the forward and backward conversion switch is operated to a neutral position. When operating the operation lever 28a in this state, the control valve 27 is changed according to the operation amount, and the boom cylinder 4d is driven.

At this time, the target rotational speed Nd is selected by the selection part 44 by the calculation by the control circuit 30, and the target rotational speed Nd by the setting dial 34 and the target rotational speed Nx by the setting dial 34 are carried out by the selection part 44. FIG. The larger value of is selected. Therefore, if the target rotational speed Nx by the setting dial 34 is set to a value suitable for work, the fluctuation of the engine rotational speed can be suppressed irrespective of the operation of the travel pedal 22a, and good workability can be obtained. have.

(2) dial mode

Next, the case where the dial mode is selected by the conversion switch 35 will be described. In the dial mode, the engine speed is set by the operation of the setting dial 34, not by the operation of the travel pedal 22a. According to FIG. 5, the rotation speed is not selected by the selection units 44 and 45. The engine speed is controlled to the value set by the setting dial 34. In this mode, since the engine speed is set by the setting dial 34, the engine speed does not change even when the traveling pedal 22a is operated, and only the conversion amount of the control valve 25 is changed and the speed is controlled. . Therefore, if the engine speed is set to a predetermined low speed by the setting dial 34, for example, the speed corresponding to the maximum discharge flow rate of the main pump 24 corresponding to the engine speed can be set as the maximum speed. Therefore, it is suitable for the case where it is desired to limit the traveling speed to a predetermined speed or less, or to drive the vehicle at a constant speed.

In the dial mode, the target rotation speed Nx by the setting dial 34 is selected by the mode converting section 46, and the target rotation speed Nx is set as the rotation speed command value Nin. As a result, the engine speed is controlled at the target speed Nx regardless of the operation of the travel pedal 22a. That is, the pump discharge amount changes according to the dial operation amount.

Therefore, when the driving pedal 22a is operated to the maximum, the hydraulic oil according to the target rotational speed Nx is supplied to the traveling motor 5, and the maximum speed of the vehicle can be adjusted by the operation of the setting dial 34. In this case, increasing the dial operation amount increases the engine speed to increase the maximum running speed, and decreasing the dial operation amount decreases the engine speed to lower the maximum running speed. As a result, the vehicle can be driven at a constant speed at a predetermined speed while the travel pedal 22a is fully depressed. As a result, it is not necessary to adjust the pedal operation amount, which reduces the burden on the driver.

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

(1) The pedal mode or the dial mode is selected in accordance with the changeover of the changeover switch 35, and in the pedal mode, the larger value of the target rotation speed Nt, Nd by the pedal operation and the target rotation speed Nx by the dial operation is selected. In the dial mode, the target rotational speed Nx by dial operation is selected. As a result, the vehicle travel speed when the travel pedal 22a is operated to the maximum in the dial mode is a value corresponding to the dial operation amount X. FIG. As a result, the speed adjustment of the vehicle becomes easy, and constant speed travel can be performed easily. In pedal mode, driving torque can be generated to the maximum, making it easy to drive at high speeds.

(2) Since the changeover switch 35 is provided in the vicinity of the setting dial 34, the changeover switch 35 can be operated without removing the hand from the setting dial 34. As a result, constant speed travel and normal travel can be switched immediately.

(3) Running target rotational speed Nt and working target rotational speed so that the increase inclination and maximum rotational speed Ntmax of the target rotational speed Nt at the time of driving become larger than the increase inclination of the target rotational speed Nd and the maximum rotational speed Ndmax at the time of operation, respectively. The characteristics of Nd are set separately. Accordingly, in the pedal mode, good running acceleration can be obtained, and the inclination of the target target rotation speed Nd is small, so that the engine speed can be easily adjusted during the operation.

(4) Since the travel switch and the job are detected by the brake switch 32 and the position sensor 33, and the target rotation speed Nt or Nd is selected according to the detection result, it is necessary to separately perform an operation for selecting the target rotation speed. none.

Incidentally, in the above embodiment, three target rotational speed calculating sections 41 to 43 are formed, but the target rotational speed calculating section 42 may be omitted. Although the selection member was comprised by the changeover switch 35, you may comprise with operation members (for example, a dial) other than a switch. Although the 2nd setting member was comprised by the setting dial 34, you may comprise with operation parts other than a dial (for example, a pushbutton switch, a linear slide switch, etc.). Although the running state was determined by the signals from the brake switch 32 and the position sensor 33 as the determination means, the running state may be determined by the vehicle speed sensor or the like.

In the above embodiment, the maximum value selector 45 selects the larger value of the target rotational speed Nt or Nd and the target rotational speed Nx, but omits the maximum value selector 45 as shown in FIG. 8. You may also Accordingly, regardless of the operation amount of the setting dial 34, the engine speed is set by the operation of the travel pedal 22a in the pedal mode, and the engine speed is adjusted by the operation of the setting dial 34 in the dial mode. Can be set. That is, independent engine control by the running pedal 22a and the setting dial 34 is possible.

As mentioned above, although the example which made speed adjustment of the traveling hydraulic motor 5 easy was shown, it is not limited to this, For example, you may apply to the turning hydraulic motor which turns the upper swing body of a vehicle. Therefore, the 1st operation member is not limited to the traveling pedal 22a, either.

As mentioned above, although the wheel type hydraulic excavator was demonstrated as an example as a construction machine, this invention is applicable also to construction machines other than a wheel type.

Claims (8)

Construction having a hydraulic pump driven by a prime mover, an actuator driven by pressure oil discharged from the hydraulic pump, and a control valve for controlling the flow of pressure oil from the hydraulic pump to the actuator in accordance with an operation of a first operation member In the prime mover control device of the machine, First setting means for setting a first set rotational speed of the prime mover in accordance with an operation of the first operating member; Second setting means for setting a second set rotation speed of the prime mover in accordance with an operation of a second operating member; A selection member for selecting the first mode or the second mode, When the first mode is selected by the selection member, the prime mover rotation speed is controlled by a larger value of the first set rotation speed and the second set rotation speed, and when the second mode is selected by the selection member, Speed control means for controlling prime mover speed by 2 set speed A prime mover control device for a construction machine, comprising: a. Construction having a hydraulic pump driven by a prime mover, an actuator driven by pressure oil discharged from the hydraulic pump, and a control valve for controlling the flow of pressure oil from the hydraulic pump to the actuator in accordance with an operation of a first operation member In the prime mover control device of the machine, First setting means for setting a first set rotational speed of the prime mover in accordance with an operation of the first operating member; Second setting means for setting a second set rotation speed of the prime mover in accordance with an operation of a second operating member; A selection member for selecting the first mode or the second mode, Rotation to control the prime mover speed at the first set speed when the first mode is selected by the selection member, and to control the prime mover speed at the second set speed when the second mode is selected by the selection member. Can control means A prime mover control device for a construction machine, comprising: a. The method according to claim 1 or 2, And said first operating member is a pedal type operating member, and said second operating member is a manual operating member. The method according to claim 1 or 2, The selection member is installed in the vicinity of the second operation member, prime mover control device for a construction machine. The method according to claim 1 or 2, The actuator is a prime mover control device for a construction machine, characterized in that the traveling motor. The prime mover control device for a construction machine according to claim 5, further comprising determining means for determining whether the vehicle is in a running state or a working state, And the first setting means sets the first set rotation speed to a larger value than when a working state is detected, when the running state is determined by the determining means. The method of claim 6, The determining means has brake detecting means for detecting brake non-operation, and neutral detecting means for detecting neutral operation of the first operating member, and it is determined that the vehicle is in a running state when brake non-operation and neutral operation are detected. Prime mover control device of construction machinery. Hydraulic pump driven by prime mover, An actuator driven by the pressurized oil discharged from the hydraulic pump, A control valve for controlling the flow of pressure oil from the hydraulic pump to the actuator in accordance with the operation of the first operating member; The prime mover control apparatus of the construction machine of Claim 1 or 2. Wheeled hydraulic excavator provided with.

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