JPH02261132A - Fine operation control for construction machine - Google Patents

Abstract

PURPOSE:To eliminate any influence of another load due to switching of a circuit, and also improve a fine operation property by driving left and right travel motors and a working machine actuator by switching a circuit. CONSTITUTION:Left and right travel motors 4 and 5 are driven with an independent circuit by discharge oil pressure of hydraulic pumps 2 and 3 at the time of travel operation only. The left and right travel motors 4 and 5 are driven by discharge oil pressure of one side hydraulic pump 2, and a working machine actuator 6 is driven by discharge oil pressure of the other side hydraulic pump 3 respectively at the time of concurrent operation of the travel and a working machine. On the other hand, when a fine operation command is given from a sub-controller 23, the left and right travel motors 4 and 5 are driven with a discharge circuit of the hydraulic pump 2 open, a discharge circuit of the hydraulic pump 3 becomes close, and also the working machine actuator 6 is operated. This enables the working machine to be driven without receiving any influence of speed variation at the time of fine operation.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a construction machine in which a plurality of actuators are switched and controlled by an input signal from a controller using the discharge hydraulic pressure of two hydraulic pumps, and in particular a hydraulic power plant. This invention relates to a control method for construction machinery that improves fine control of excavators.

(Conventional technology) Conventionally, in hydraulic power excavators, the traveling, working equipment,
Normally, multiple hydraulic pumps are installed to distribute power when hydraulically driving swings, etc. Of these, two hydraulic pump systems are often used to drive the left and right travel motors, work equipment, actuators for swings, etc. An example of the control circuit will be explained with reference to FIG. The left and right travel motors 4 and 5 and the work equipment actuator 6 are installed in the discharge circuits of the two pumps 2 and 3 driven by the engine I. and pilot check valve 7 on the meter-out side,
8 is opened and driven by an input signal from a pilot valve 9, and the left running motor 5 is connected to pilot check valves on the meter-in side and meter-out side provided in the 3-side pump circuit and the 2-side pump circuit. 10,11.
12 are opened and driven by input signals from pilot valves 13 and 14, respectively. Further, the work implement actuator 6 is provided in the third side pump circuit, and a meter-out side pilot check valve 15 is opened and operated by an input signal from a pilot valve 16. Commands to these actuators are sent to the pilot valve from an output signal controller 19 by operating a travel control lever 17 and a work equipment control lever 18, which are electric levers, and when traveling alone, both pumps are 2.3, the respective hydraulic pumps drive the left and right travel motors by independent circuits for the left and right travel motors 4 and 5.

For this purpose, the pilot check valves 7, 8 to the right-hand drive motor 4 and the pilot check valves 10, 12 to the left-hand drive motor 5 from the third-side pump circuit are opened, and the pilot check valves 10, 12 to the right-hand drive motor 4 from the third-side pump circuit are opened. The pilot check valve j1 to the work machine actuator and the pilot check valve J5 to the work machine actuator are closed.

Furthermore, when traveling and operating the work equipment at the same time, the hydraulic pressure discharged from one hydraulic pump 2 is used to drive the left and right travel motors 45, and the hydraulic pressure discharged from the other hydraulic pump 3 is used to operate the work equipment Actiecro. It has become. For this purpose, pilot check valves 7, 8, 1 for left and right travel motors 4, 5 are installed.
1. ], 2 and the pilot valve of the work equipment actiekro 1
5 is opened, and the pilot check valve 10 of the left travel motor 5 is closed.

In such a hydraulic pump system, the fine operation switch 2 is used during fine operation of the work equipment such as lifting work.
By turning on 0, the output signal is sent from the controller 19 to the work equipment actuator 6 and the left and right travel motors 4 and 5.
The command is given to each pilot valve to control the opening degree of each pilot check valve, so that the discharge flow rate can be reduced to, for example, half of that during normal operation, allowing fine operation at low speed. Ta.

(Problem to be Solved by the Invention) However, in the two hydraulic pump systems described above, even when the fine operation switch 20 is turned on, when switching from independent running to simultaneous operation with a working machine, Conversely, if you switch from simultaneous operation to independent travel, the speed of the operator operating first will decrease, and the switch will cause a shock, making it difficult to coordinate with auxiliary workers during lifting operations, and making it difficult for the operator to operate. There is a problem in that the actuator operates earlier or later than intended, creating a danger. Of course, such problems in fine control occur not only in operating the work machine but also in driving.

Moreover, the conventional fine operation merely reduces the maximum discharge flow rate, and the operating speed of the work machine and traveling speed relative to the amount of change in the operating lever is as shown in Fig. 2 (A). ), the fine control (n) was linear, and even when the operating lever moved slowly, these moved quickly, making it difficult to control and roll the fine control.

The present invention eliminates speed changes and shocks caused by the influence of the load on the other machine, which are caused by mutual switching between solo running and simultaneous operation with a work machine, which are problems during the above-mentioned fine operation, and also eliminates fast movement that differs from the sense of fine operation. The purpose is to improve fine controllability by eliminating the operation pattern of

(Means and operations for solving the problem) In order to achieve the above object, the present invention supplies the discharge hydraulic pressure of two hydraulic pumps driven by an engine to the left and right traveling motors and the work equipment actuator. By switching the circuit, when traveling alone, both hydraulic pumps drive the left and right travel motors, and when traveling and operating the work equipment simultaneously, one hydraulic pump drives the left and right travel motors, and the other hydraulic pump drives the left and right travel motors. In addition to activating the work equipment actuator, at the same time as switching to the fine operation mode, both hydraulic pump circuits are separated and independent, so that the left and right travel motors are independently driven by one hydraulic pump, and the work equipment actuator is independently driven by the other hydraulic pump. In addition, in the fine operation mode, the speed of the operating system in response to the amount of change in the operating lever is initially slow and gradually increases in a curve-like manner, and the maximum speed is compared with that during normal operation. This purpose was achieved by making the operation pattern characteristics slower.As a result, the travel and work equipment circuits are separated and independent at the same time as the switching from normal work to fine operation, so that during fine operation, the load on the other actuator is reduced. unaffected. Furthermore, due to the fine operation pattern characteristics, smooth movement can be achieved at the time of startup.

(Example) Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a hydraulic circuit for a hydraulic power excavator, which is similar to the conventional circuit already described in FIG. 4 and 5 are left and right travel motors, 6
is a work equipment actuator that collectively refers to work equipment actuators such as booms, arms, packets, swing motors, etc., and these actuators transmit electrical signals to indicate the amount of change in operation of the travel control lever 17 and the work control lever 18, which are electric levers. The converted output is output to each pilot valve and pilot check valve group via the controller 21 for drive control.When traveling alone, both hydraulic pumps 2,
The left and right travel motors 4 and 5 are driven by independent circuits using the discharge oil pressure of one hydraulic pump 2, and when the travel and work equipment are operated simultaneously, the left and right travel motors 4 and 5 are driven by the discharge oil pressure of one hydraulic pump 2, and the other hydraulic pump 3. The working machine actuator 6 is driven by the discharge hydraulic pressure of the hydraulic pressure. In this control circuit, reference numeral 23 is a subcontroller into which a fine operation pattern is preset and input, and the operation pattern is a linear operation pattern (1 ), the fine operation pattern (III) is a curved operation pattern in which the operating speed of the work equipment actuator 6 is gradually increased and then gradually accelerated with respect to the stroke of the operating lever, as shown in the figure. With,
The maximum speed is also one-half slower than during normal work.

This is to gently drive the operation systems for the work equipment, travel, etc. in accordance with the operating sensation during fine operation.

22 is a switch for selecting a fine operation mode;
When a fine operation command is issued through the controller 19 from the sub-controller 23 to which the above-mentioned fine operation pattern is input by the N operation, one of the hydraulic pumps 2
Pilot check valves 7, 8, 11.12 on the meter-in side and meter-out side of the discharge hydraulic circuit are opened by pilot valves 9.14, respectively, to drive the left and right travel motors 4,5. Further, the pilot check valve 10 on the meter-in side to the left travel motor 5 of the discharge hydraulic circuit of the other hydraulic pump 3 is closed by the pilot valve 13, and the pilot check valve 15 on the meter-in side of the work machine actuator is closed as a pilot valve. 16 opens and the work equipment actuator 6 is opened by controlling the flow rate and speed using the fine operation pattern.
becomes operational.

While in fine control mode, both hydraulic pump circuits are completely separated and independent, regardless of whether the drive is operated alone or operated simultaneously with the work equipment. Since the machine is driven by the same amount of power, it starts slowly and runs at low speed when traveling alone with fine control, and even when traveling and operating the work equipment at the same time, each fine control is performed without being affected by the load of the other. It's my turn.

Then, by turning off the fine operation mode switch 22, the previous fine operation mode is canceled and normal work operation is resumed.

(Effects of the Invention) Since the present invention is configured as described above, during fine operation, there is no shock caused by switching between simultaneous operation and single operation, and there is no effect of speed changes, and the operation pattern that matches the sense of fine operation is used. Since the machine can travel and drive the working equipment, it is possible to perform work with accurate and safe fine operation, and as a result, work efficiency is improved and the work area can be expanded.

[Brief explanation of drawings]

Fig. 1 is a fine operation control circuit diagram for a hydraulic power excavator showing an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between the operating lever stroke and the speed of the operating system during fine operation, and Fig. 3
The figure is a circuit diagram showing an example of a fine operation control circuit of a conventional hydraulic power shovel. 2.3... Hydraulic pump, 4.5... Left and right travel motor, 6... Work equipment actuator, 17... Travel lever 19.21... Controller, 20.22... Fine operation switch , 23...Sub controller.

Claims (1)

[Scope of Claims] 1. In a device in which the discharge hydraulic pressure of two hydraulic pumps driven by an engine is supplied to the left and right travel motors and the work equipment actuator, when the vehicle is traveling alone by switching the circuit, both the hydraulic pressures are The left and right travel motors are driven by the pumps, and when the travel and work equipment are operated simultaneously, one hydraulic pump drives the left and right travel motors, and the other hydraulic pump operates the work equipment actuator, and at the same time when switching to fine operation mode. , both hydraulic pump circuits are separated and independent, the left and right travel motors are driven independently by one hydraulic pump, and the work equipment actuator is driven by the other hydraulic pump, so that during fine operation, there is no influence of the load on the other actuator. 1. A fine operation control method for construction machinery, characterized in that the fine operation control method for construction machinery is prevented from being affected. 2. The fine operation mode characteristic is an operation pattern in which the speed change of the operation system in response to the amount of change in the operation lever is slow at the beginning of the stroke and then gradually accelerates in a curved manner, and the maximum speed is lower than that in normal operation. A fine operation control method for construction machinery according to claim 1.