JP7420677B2 - construction machinery - Google Patents

Description

The present invention relates to a construction machine equipped with means for controlling two actuators with one directional control valve.

As a typical example of construction machinery, a hydraulic excavator has a self-propelled lower traveling body, an upper rotating body rotatably supported on the lower traveling body, and a working machine rotatably supported in front of the upper rotating body. An earth removal device for removing earth and sand is installed in front of the center frame of the lower traveling body.

The earth removal device consists of an arm that is swingably supported with respect to a center frame, a blade attached to the tip of the arm, a lift cylinder that performs a lifting operation that swings the arm vertically, and a long blade. A tilt cylinder that performs a tilt operation that swings one end of the blade upward and the other end downward, and an angle action that swings one end of the blade lengthwise forward and the other end backwards. It is composed of an angle cylinder that performs this.

On the other hand, the upper revolving body consists of a turning frame, an engine that rotates a hydraulic pump and sends oil to an actuator, a control valve that is an assembly of directional valves that control the direction and amount of oil flowing to the actuator, and a control valve that controls the direction and amount of oil flowing to the actuator. The valve is equipped with a driver's seat that has an operating lever that sends pilot pressure to the valve and operates each actuator.

Here, in the conventional soil removal device, the blade is caused to lift by the swinging operation of the dozer lever, and the changeover switch installed on the operating knob of the dozer lever is used to switch to tilt or angle operation. Then, perform the tilt operation or angle operation selected by the operation switch installed near the changeover switch. (Patent Document 1)

At that time, the tilt cylinder and angle cylinder are switched via an oil passage and a selector valve that extend from a directional switching valve that is controlled by pilot pressure that is sent from an electric remote control valve that is controlled by a current that is sent from an operation switch. They are freely connected.

Referring to FIG. 13, switching of a selector valve using a conventional changeover switch and control of an angle cylinder and a tilt cylinder using an operation switch will be explained.

The pilot pressure input port of the selector valve is connected to the oil passage extending from the pilot pump via the solenoid valve 800. By pressing the changeover switch 810, the solenoid valve 800 is energized, and the pilot pressure of the selector valve is input. Pilot pressure is input to the port, and the selector valve communicates the angle cylinder and the directional control valve.

By pressing the operation switches 811 and 812, the pilot pressure output from the electric remote control valves 820 and 821 is input to the pilot pressure input port of the directional control valve, the angle cylinder operates, and the blade performs the angle operation. conduct.

Further, when the press of the changeover switch 810 is interrupted, the current input to the solenoid valve 800 is cut off, pilot pressure is not input to the pilot pressure input port of the selector valve, and the selector valve communicates the tilt cylinder and the directional control valve. .

By pressing the operation switches 811 and 812, pilot pressure is inputted from the electric remote control valves 820 and 821 to the pilot pressure input port of the directional control valve, the tilt cylinder is driven, and the blade performs a tilt operation.

JP2005-207195

In a construction machine equipped with an earth removal device, when performing an angle operation after performing a tilt operation, the operator must press a changeover switch and then an operation switch each time, resulting in a problem of lack of smooth operation. there were.

As a means of solving this problem, we eliminated the changeover switch from the conventional technology, provided a tilt operation switch and an angle operation switch separately, and created an electric circuit that switches the flow path of the selector valve from the tilt cylinder to the angle cylinder when the angle operation switch is pressed. It is possible to configure

In the above configuration, when the angle operation switch is released after being pressed, the flow path of the selector valve returns from the angle cylinder to the tilt cylinder, and the pressure at the pilot pressure input port of the directional control valve is The pressure is reduced, and the spool of the directional control valve tries to return to the neutral position by the force of the spring, and the opening of the spool closes.

However, the speed at which the spool of the directional control valve is moved from the switching position to the neutral position is slower than the speed at which the selector valve switches, and pressure builds up between the selector valve and the directional control valve, causing the tilt cylinder to close when not operated. There is a problem that there is a possibility that it may move.

The present invention has been made in view of the above-mentioned problems of the prior art, and aims to provide a construction machine that controls two actuators with one directional control valve and has both operability and responsiveness.

In order to solve the above-mentioned problems, the present invention provides an actuator driven by pressure oil fed from a hydraulic pump, a directional switching valve that controls the actuator by switching the flow rate and direction of the pressure oil, and a directional switching valve that controls the actuator by switching the flow rate and direction of the pressure oil. a flow path switching means for freely switching a flow path that is located between a flow path connecting the valve and the actuator and communicates with the directional control valve from a first state in which the flow path is in communication with the actuator to a second state in which the flow path is in communication with another actuator; a flow path holding means that maintains the second state inside and maintains the first state when stopped; a first operating means that operates the actuator; and a second operating means that operates the other actuator; In the construction machine, the construction machine includes a first control means that starts the flow path holding means while the second operation means is operated, and a first control means that starts the flow path holding means when the second operation means is stopped. Applied to a construction machine characterized by comprising a second control means for stopping the road holding means after starting the road holding means for a specified time.

According to the present invention, when two actuators are controlled by one directional valve via the flow path switching means, both operability and responsiveness can be achieved at low cost.

A perspective view of a construction machine according to an embodiment of the present invention A perspective view of a driver's seat of a construction machine according to an embodiment of the present invention A front view of a grip part of a dozer lever of a construction machine according to an embodiment of the present invention Hydraulic circuit diagram for controlling tilt and angle operations of a construction machine according to an embodiment of the present invention Electric circuit diagram for controlling tilt operation and angle operation according to an embodiment of the present invention A control flow diagram of an electric circuit and a hydraulic circuit that control tilt and angle operations of a construction machine according to an embodiment of the present invention. A control flow diagram of an electric circuit and a hydraulic circuit that control tilt and angle operations of a construction machine according to an embodiment of the present invention. A control flow diagram of an electric circuit and a hydraulic circuit that control tilt and angle operations of a construction machine according to an embodiment of the present invention. Control block diagram of tilt and angle operations of a construction machine according to a modification of the embodiment of the present invention A flow diagram of electronic control of a hydraulic circuit that controls tilt and angle operations of a construction machine according to a modification of the embodiment of the present invention. A flow diagram of electronic control of a hydraulic circuit that controls tilt and angle operations of a construction machine according to a modification of the embodiment of the present invention. A flow diagram of electronic control of a hydraulic circuit that controls tilt and angle operations of a construction machine according to a modification of the embodiment of the present invention. Electrical circuit diagram for controlling tilt and angle movements of construction machinery according to conventional technology

Hereinafter, an embodiment of a construction machine according to the present invention will be described in detail using a hydraulic excavator 100 as an example with reference to FIG.

As a typical example of a construction machine, a hydraulic excavator 100 includes a self-propelled lower traveling body 200, an upper rotating body 300 rotatably supported on the lower traveling body 200, and a rotating upper body 300 that is rotatable in front of the upper rotating body 300. The working device 400 is supported by a working device 400.

The upper rotating body 300 is rotated by a rotation motor (not shown) via a rotation bearing (not shown), and controls the direction and amount of oil flowing to actuators that move the working device 400 and the earth removal device 500. The hydraulic excavator is equipped with a control valve (not shown) which is a collection of directional valves, and a driver's seat 320 having an operating lever 310 for sending pilot pressure to the control valve and operating the hydraulic excavator.

The working device 400 includes a swing bracket 410 that is horizontally rotated and supported by a swing cylinder (not shown) installed on the upper revolving body 300 on a swing post 330 provided at the tip of the upper revolving body 300; A boom 420 is supported by a swing bracket 410 so as to be rotatable up and down, an arm 430 is attached to the tip of the boom 420 so as to be pivotable up and down, and a bucket 440 is attached to the tip of the arm 430 so as to be pivotable. It consists of a boom cylinder 421 installed below the boom 420 to move the boom 420, an arm cylinder 431 installed above the boom 420 to move the arm 430, and an arm cylinder 431 installed above the arm 430 to move the bucket 440. A moving bucket cylinder 441 is provided.

The lower traveling body 200 has a center frame (not shown) and side frames 210 and 220 that are symmetrically paired with the center frame (not shown) and extend in the front and back direction, and the side frame has one rear end side. A drive wheel 221 (only the left side is shown) driven by a traveling motor is installed at the front end, and a plurality of idle wheels 222 (only the left side is shown) are installed toward one front end. Crawler belts 223 and 224 are wound around the drive wheel 221 and the idler wheel 222, and an earth removal device 500, which will be described later, is attached to the front of the center frame.

The earth removal device 500 performs a lifting operation on an arm 510 that is swingably supported with respect to a center frame, a blade 520 that is attached to the tip of the arm 510, and a blade 520 that swings the arm 510 in the vertical direction. a lift cylinder 530 that tilts the blade 520 by swinging one longitudinal end of the blade 520 upward and the other end downward; An angle cylinder 550 (shown only on the left side) that swings one end forward and the other end backward to cause the blade 520 to perform an angular motion, and an inner proximal end of one of the pair of vertical plates making up the arm 510. is equipped with a selector valve (not shown).

The selector valve 630 connects one directional switching valve 620 of the control valve, the tilt cylinder 540, and the angle cylinder 550 in a freely switchable manner, and the directional switching valve is connected to the tilt cylinder 540 or the angle cylinder 550 which is switched by the selector valve 630. Change the flow rate and direction of oil flowing to the

The configuration of the driver's seat 320 will be further described with reference to FIG. 2. The driver's seat 320 is arranged above the upper revolving structure 300, stands upright from the middle of the driver's seat floor 321, and a seat 323 is installed on a seat mount 322 extending rearward, and on one side in front of the seat 323, A boarding gate 324 is installed, and a console 326 with a monitor 325 attached to the front is placed on the other side. In front of the seat 323, operating levers 311 and 312 for operating left and right travel motors (not shown) are provided upright, and on the left and right sides of the seat 323, a boom 420, an arm 430, a bucket 440, and a rotating motor are provided. A pair of left and right side levers 313 and 314 are attached to operate a motor (not shown). A dozer lever 315 for operating the earth removal device 500 is provided upright on the console 326 .

The configuration of the dozer lever 315 will be described with reference to FIGS. 2 and 3. The dozer lever 315 includes a grip portion 315a and a lever body 315b.

Angle operation switches 316 and 317 for performing angle operation are arranged above the grip part 315a and in front as seen from the driver sitting on the seat 323. When one of the angle operation switches 316 and 317 is pressed, One end of the blade 520 performs an angle operation in which it rotates forward, and when the other of the angle operation switches 316 and 317 is pressed down, the other end of the blade 520 performs an angle operation in which it rotates forward. Further, tilt operation switches 318 and 319 for performing a tilt operation are arranged below the angle operation switches 316 and 317, and when the tilt operation switches 318 and 319 are pressed, one end of the blade 520 rotates upward. When the blade 520 is operated and the other of the tilt operation switches 318 and 319 is pressed down, the other end of the blade 520 rotates upward to perform a tilt operation.

A hydraulic circuit that controls the tilt operation and the angle operation will be described with reference to FIG. 4. An oil passage extending from the pump 600 forms a center bypass to an oil tank 610, and a directional control valve 620 is installed between the oil tank 610 and the pump 600.

A tilt cylinder 540 and an angle cylinder 550 are arranged in the oil passage downstream of the directional switching valve 620, and a selector valve 630 is arranged between the directional switching valve 620 and the tilt cylinder 540 and the angle cylinder 550.

An oil passage extending from the directional switching valve 620 is switchably connected to a tilt cylinder 540 or an angle cylinder 550 via a selector valve 630.

In the neutral position 630a, the selector valve 630 connects the directional control valve 620 to the oil passage of the tilt cylinder 540, and when the tilt operation switches 318, 319 are operated, the electric remote control valves 640, 641 switch to the pilot pump. The pilot pressure sent from 601 is outputted to the input ports 620a, 620b of the directional switching valve 620, and the tilt cylinder 540 is driven to perform a tilt operation.

Next, when the angle operation switches 316 and 317 are operated, the solenoid valve 650 inputs the pilot pressure sent from the pilot pump 601 to the pilot port 630c of the selector valve 630. As a result, the selector valve 630 switches from the neutral position 630a to the switching position 630b, and the oil passage extending from the directional switching valve 620 is connected to the oil passage extending from the angle cylinder 550.

The electric remote control valves 640, 641 can input the pilot pressure fed from the pilot pump 601 into the input ports 620a, 620b of the directional switching valve 620, drive the angle cylinder 550, and perform an angle operation.

Next, an electric circuit for controlling the tilt operation and the angle operation will be explained based on FIG. Electrical circuits extending from the angle operation switches 316, 317 and the tilt operation switches 318, 319 extend to electric remote control valves 640, 641, and when the angle operation switches 316, 317 or the tilt operation switches 318, 319 are closed, the electric remote control valve 640 is closed. , 641 are energized.

Electric remote control valves 640, 641 from angle operation switches 316, 317
The electric path extending to the first relay 700 branches to form an electric path extending to the first relay 700.

When the angle operation switches 316 and 317 are pressed down, the first relay 700 is operated, the contact AC is opened, the contact AB is closed, and the solenoid valve 650 is energized.

When the depression of the angle operation switches 316 and 317 is stopped, the first relay 700 is stopped, the contact AB is opened, the contact AC is closed, and the current to the solenoid valve 650 is cut off.

At the same time, timer relay 710 operates to energize second relay 720 for a specified time, contact DF opens, and contact DE closes to energize solenoid valve 650.

After the specified time has elapsed, the contact DE is opened and the contact DF is closed to cut off the energization of the solenoid valve 650.

The timer relay 710 is a relay that allows current to flow for a set time in a circuit when the current supply for operating the relay transitions from a cutoff state to a conduction state.

The time to be set should be around the time required for the spool of the directional control valve 620 to slide from the open position to the neutral position, and by setting it to a degree that slightly exceeds this time, the time can be changed from angle operation to tilt operation. switching becomes smoother. The set time is appropriately set depending on the size and type of the directional switching valve 620.

Electrical paths extending from the tilt operation switches 318 and 319 to the electric remote control valves 640 and 641 branch to form an electric path extending to the relay 730.

When the tilt operation switches 318, 319 are pressed while the contact DE is closed, the third relay 730 operates, the contact GI opens, the contact GH closes, the second relay 720 stops, and the energization of the solenoid valve 650 is cut off. be done.

Next, referring to FIGS. 6 to 8, by operating the tilt operation switches 318 and 319 and the angle operation switches 316 and 317, the electric circuit that controls the tilt operation and the angle operation is changed to the hydraulic circuit that controls the tilt operation and the angle operation. We will explain step by step how to control.

In step S1, when the tilt operation switches 318 and 319 are pressed, the process moves to step S8, where the electric remote control valves 640 and 641 are energized and input pilot pressure to the input ports 620a and 620b of the directional control valve 620, The spool of the directional control valve 620 slides from the neutral position to the open position, and the tilt cylinder 540 is driven by pressure oil fed from the pump 600 to perform a tilt operation.

When the tilt operation switches 318, 319 are stopped being pressed in step S9, the electric remote control valves 640, 641 are de-energized in step S10, and the spool of the directional control valve 620 slides from the open position to the neutral position. The pressure oil fed from the pump 600 is cut off, the tilt cylinder 540 is stopped, and the tilt operation is stopped.

If the angle operation switch is pressed in step S2 without pressing the tilt operation switches 318, 319 in step S1, the electric remote control valve is energized in step S3.

At the same time, an electric line branching from the electric line extending from the angle operation switches 316, 317 to the electric remote control valves 640, 641 and extending to the first relay 700 is also energized, and the first relay 700 is operated.

When the first relay 700 operates, the contact AC opens, the contact AB closes and the solenoid valve 650 is energized, and the solenoid valve 650 inputs pilot pressure to the pilot port 630c of the selector valve 630. As a result, the selector valve 630 switches from the neutral position 630a to the switching position 630b, and the oil passage extending from the angle cylinder 550 and the oil passage extending from the directional switching valve 620 are connected.

In step S4, the solenoid valves 640 and 641 input pilot pressure to the input ports 620a and 620b of the directional control valve 620, and the spool of the directional control valve 620 slides from the neutral position to the open position, and the pump 600 pumps the pilot pressure. The angle cylinder 550 is driven by the pressurized oil and performs an angle operation.

Through these controls, the flow path is switched from the tilt cylinder to the angle cylinder and the flow path is maintained in accordance with the operation of the angle operation switch, so that operability and responsiveness can be improved.

When pressing the angle operation switches 316, 317 is stopped in step S5, the electric remote control valves 640, 641 are de-energized in step S6, and the spool of the directional control valve 620 slides from the open position to the neutral position. Then, the pressure oil fed from the pump 600 is cut off, the angle cylinder 550 is stopped, and the angle operation is stopped.

At the same time, in step S7, the first relay 700 is de-energized, the first relay 700 is stopped, the contacts AB are opened, and the contacts AC are closed.

In step S11, the timer relay 710 operates, and the second relay 720 operates, thereby opening the contact DF, closing the contact DE, and energizing the solenoid valve 650.

In step S12, the solenoid valve 650 inputs pilot pressure to the pilot port 630c of the selector valve 630, and as a result, the selector valve 630 maintains the switching position 630b, and connects the oil passage extending from the directional switching valve 620 to the angle cylinder 550. Maintain it connected to the extending oil path.

In step S13, when the time t seconds during which the timer relay 710 can pass the current has elapsed, the operation of the second relay 720 is stopped, the contact DE opens, and the contact DF closes.

In step S14, the electromagnetic valve 650 is de-energized, and the selector valve 630 switches from the switching position 630b to the neutral position 630a to connect the oil passage extending from the directional switching valve 620 to the oil passage extending from the tilt cylinder 540.

Through these controls, in response to the stoppage of the angle operation switches 316 and 317, the spool of the directional control valve 620 changes from the switching position to the neutral position while maintaining the flow path of the directional control valve 620 and the flow path of the angle cylinder 550 for a certain period of time. Therefore, no pressure is built up between the directional control valve 620 and the selector valve 630, and as a result, the tilt cylinder 540 does not move even when the tilt operation switches 318 and 319 are not pressed. Improved operability and responsiveness can be achieved at low cost.

In step S13, before the time t seconds during which the timer relay 710 can pass the current has elapsed, in step S14, the tilt operation switches 318 and 319 are pressed.

In step S15, the electric path extending from the electric path extending from the tilt operation switches 318, 319 to the electromagnetic valves 640, 641 to the relay 730 branched off is also energized, and the relay 730 is operated. When the third relay 730 operates, the contact GI opens and the contact GH closes.

In step S16, the operation of the timer relay 710 is stopped, and thereby the operation of the second relay 720 is stopped, and the contact DE is opened and the contact DF is closed.

In step S17, the electromagnetic valve 650 is de-energized, and the selector valve 630 switches from the switching position 630b to the neutral position 630a to connect the oil passage extending from the directional switching valve 620 to the oil passage extending from the tilt cylinder 540.

Simultaneously with step S15, the process moves to step S8, where the electromagnetic valves 640 and 641 are energized, pilot pressure is input to the input port of the directional control valve 620, and the spool of the directional control valve 620 is slid from the neutral position to the open position. The tilt cylinder 540 is driven by pressure oil fed from the pump 600 to perform a tilt operation.

When the tilt operation switches 318 and 319 are stopped being pressed in step S9, the electromagnetic valves 640 and 641 are de-energized in step S10, and the spool of the directional control valve 620 slides from the open position to the neutral position, and the pump 600 The pressure oil fed from the cylinder 540 is cut off, the tilt cylinder 540 is stopped, and the tilt operation is stopped.

With these controls, even if the tilt operation switches 318 and 319 are pressed immediately after the angle operation switches 316 and 317 are stopped, the flow path is quickly switched from the angle cylinder 550 to the tilt cylinder 540, improving operability and response. You can increase your sexuality.

A modification of the embodiment will be described based on FIG. 9. FIG. 9 is a block diagram showing control of tilt operation and angle operation. Operation signals of tilt operation switches 318, 319 and angle operation switches 316, 317 are input to ECU 800 (electronic control unit) and transmitted from ECU 800. The signal is output to the solenoid valve 650 and the electric remote control valves 640 and 641.

The ECU 800 is connected to the 12-volt battery installed in this machine, and has a power supply that supplies stable voltage to each block in the ECU 800, an input buffer that converts digital input signals to a signal level that can be input to the microcontroller, and an analog signal. An AD converter that converts the data into digital values that can be input to a microcontroller, a microcontroller that calculates and outputs control amounts from various input signals, and an EEPROM (Electronically Erasable and (Programmable Read Only Memory), an output driver that converts the output signal of the microcontroller into a signal format that can be driven by an actuator or amplifies the voltage, and communication that converts the output data of the microcontroller into a communication signal that conforms to the communication standard. It consists of a driver and a communication receiver that converts signals sent by other ECUs to a level that can be input to the microcomputer.

Next, electronic control of the hydraulic circuit that controls the tilt operation and the angle operation will be explained with reference to FIGS. 10 to 12.

When the tilt operation switch is pressed in step S18, ON signals of the tilt operation switches 318 and 319 are input to the ECU 800.

In step S24, a signal is output from the ECU 800 to the electric remote control valves 640, 641, and the electric remote control valves 640, 641 are energized to input pilot pressure to the input port of the directional control valve 620, and the spool of the directional control valve 620 The tilt cylinder 540 slides from the neutral position to the open position, and the tilt cylinder 540 is driven by pressure oil fed from the pump 600 to perform a tilt operation.

When the depression of the tilt operation switches 318, 319 is stopped in step S25, an off signal of the tilt operation switches 318, 319 is input to the ECU 800.

The signal outputted from the ECU 800 to the electric remote control valves 640, 641 in step S26 is stopped, the electricity to the electric remote control valves 640, 641 is cut off, and the spool of the directional control valve 620 is moved from the open position. When it slides to the neutral position, the pressure oil fed from the pump 600 is cut off, the tilt cylinder 540 stops, and the tilt operation is stopped.

If the angle operation switches 316, 317 are pressed in step S19 without pressing the tilt operation switches 318, 319 in step S18, ON signals of the angle operation switches 316, 317 are input to the ECU 800.

In step S20, a signal is output from ECU 800 to solenoid valve 650, and pilot pressure is input to pilot port 630c of selector valve 630. As a result, the selector valve 630 switches from the neutral position 630a to the switching position 630b, and the oil passage extending from the angle cylinder 550 and the oil passage extending from the directional switching valve are connected.

Step S21 A signal is output from the ECU 800 to the electric remote control valves 640 and 641, and the electric remote control valves 640 and 641 are energized and input pilot pressure to the input ports 620a and 620b of the directional control valve 620. The spool slides from the neutral position to the open position, and the angle cylinder 550 is driven by pressure oil fed from the pump 600 to perform an angle operation.

When the depression of the angle operation switches 316, 317 is stopped in step S22, an off signal of the angle operation switches 316, 317 is input to the ECU 800.

In step S23, the signal output from the ECU to the electric remote control valves 640, 641 is stopped, the electricity to the electric remote control valves 640, 641 is cut off, and the spool of the directional control valve 620 is moved from the open position to the neutral position. The pressure oil fed from the pump 600 is cut off, the angle cylinder 550 is stopped, and the angle operation is stopped.

If the ECU 800 determines that t seconds have elapsed since the off signal of the angle operation switches 316, 317 was input to the ECU 800 in step S27, the signal outputted from the ECU 800 to the solenoid valve 650 in step S28 is stopped, and The energization of the valve 650 is cut off, and the selector valve 630 switches from the switching position 630b to the neutral position 630a to connect the oil passage extending from the directional switching valve 620 to the oil passage extending from the tilt cylinder 540.

Through these controls, in response to the stoppage of the angle operation switches 316 and 317, the spool of the directional control valve 620 changes from the switching position to the neutral position while maintaining the flow path of the directional control valve 620 and the flow path of the angle cylinder 550 for a certain period of time. Therefore, no pressure is built up between the directional control valve and the 620 selector valve 630, and as a result, the tilt cylinder 540 does not move even when the tilt operation switches 318 and 319 are not pressed. Improved operability and responsiveness can be achieved at low cost.

When the tilt operation switch is pressed in step S29 when t seconds have not elapsed since the OFF signal of the angle operation switches 316 and 317 was input to the ECU 800 in step S27, the ON signal of the tilt operation switches 318 and 319 was input to the ECU 800. Once input, the process moves to step S30.

The signal outputted from the ECU 800 to the solenoid valve 650 in step S30 is stopped, the energization of the solenoid valve 650 is cut off, and the selector valve 630 is switched from the switching position 630b to the neutral position 630a, and the directional switching valve 620 is switched from the switching position 630b to the neutral position 630a. The extending oil passage is connected to an oil passage extending from the tilt cylinder 540.

In step S31, a signal is output from the ECU 800 to the solenoid valves 640, 641, and the solenoid valves 640, 641 are energized to input pilot pressure to the input ports 620a, 620b of the directional valve 620, and the spool of the directional valve 620 is The tilt cylinder 540 slides from the neutral position to the open position and is driven by pressure oil fed from the pump 600 to perform a tilt operation.

When the depression of the tilt operation switches 318, 319 is stopped in step S32, an off signal of the tilt operation switches 318, 319 is input to the ECU 800.

The signal outputted from the ECU 800 to the electric remote control valves 640, 641 in step S33 is stopped, the electricity to the electric remote control valves 640, 641 is cut off, and the spool of the directional control valve 620 is moved from the open position. When it slides to the neutral position, the pressure oil fed from the pump 600 is cut off, the tilt cylinder 540 stops, and the tilt operation is stopped.

With these controls, even if the tilt operation switches 318 and 319 are pressed immediately after the angle operation switches 316 and 317 are stopped, the flow path is quickly switched from the angle cylinder 550 to the tilt cylinder 540, improving operability and response. You can increase your sexuality.

As described above, as the present embodiment, the hydraulic excavator 100 including the earth removal device 500 having a control mechanism for tilting operation and angle operation using the selector valve 630 has been described, but the present invention is not limited thereto.

For example, the present invention can also be applied to a hydraulic excavator with an offset boom. Specifically, the present invention can be applied to a case where a boom cylinder that rotates the boom up and down and an offset cylinder that offsets the offset boom are controlled by a one-way switching valve via a flow path switching means.

The present invention can also be applied to an attachment mounted on an excavator working machine that is driven by a plurality of actuators and controlled by a one-way switching valve via a flow path switching means.

Furthermore, the flow path switching means may be not only a selector valve provided outside the control valve, but also a directional switching valve that constitutes the control valve, and in that case, it is arranged downstream of the directional switching valve that controls the actuator.

The present invention is not limited to hydraulic excavators, but can also be applied to bulldozers, wheel loaders, compact track loaders, etc., and the present invention is not limited to the above-described embodiments. Changes may be made as appropriate without departing from the gist.

INDUSTRIAL APPLICATION This invention relates to a construction machine and its operation control, and has industrial applicability.

316, 317 Angle operation switch (second operation means)
318, 319 Tilt operation switch (first operation means)
540 Tilt cylinder 550 Angle cylinder 620 Directional switching valve 630 Selector valve (flow path switching means) 640, 641 Electric remote control valve 650 Solenoid valve (flow path holding means) 700 First relay (first control means)
710 Timer relay (second control means)
720 Second relay 730 Third relay (third control means)

Claims (5)

an actuator driven by pressure oil fed from a hydraulic pump;
a directional control valve that controls the actuator by switching the flow rate and direction of the pressure oil;
A flow path switch that is located between a flow path connecting the directional switching valve and the actuator and that freely switches the flow path communicating with the directional switching valve from a first state in which it communicates with the actuator to a second state in which it communicates with another actuator. means and
flow path holding means that holds the second state during startup and holds the first state when stopped;
A construction machine comprising a first operating means for operating the actuator and a second operating means for operating the other actuator,
The construction machine includes first control means for activating the flow path holding means while operating the second operation means;
A construction machine comprising: a second control means for starting the flow path holding means for a specified time and then stopping the flow path holding means when the operation of the second operation means is stopped. 2. The construction machine according to claim 1, further comprising a third control means that stops the flow path holding means when the first operation means is operated within the specified time . The first control means is a first relay activated by an operation signal from the second operation means, and the second control means is a second relay, and the construction machine is operated when the first relay is stopped. 3. The construction machine according to claim 2, further comprising a timer relay that outputs a current to the second relay for a specified time . 4. The construction according to claim 3, wherein the third control means is a third relay that is activated by an operation signal from the first operation means and interrupts the flow of current between the second relay and the timer relay. machine . Any one of claims 1 to 4, wherein the specified time is longer than the time required for the directional control valve to transition from the switching position to the neutral position by stopping the operation of the second operating means. or the construction machine described in paragraph 1 .

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