JP2000161305A - Revolution controlling method for hydraulic working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a revolution controlling method capable of performing an emergency stop at the time of revolution by boosting relief set pressure of a relief valve only when an operating lever for revolution is operated in the direction that an upper revolving body is revolved in the other direction. SOLUTION: When a revolution stop is performed, a reverse lever operation is performed. In the case, a command signal is outputted to a solenoid 40 of an electromagnetic switch valve 39 based on each of a revolving motor rotation detection signal and a lever angle detection signal from potentiometers 41, 42 in a controller 43. Because the solenoid 40 is energized, the electromagnetic switch valve 39 is switched from a cutoff oil path locating G to an opening oil path location H. Pilot pressure from a pilot pressure source 38 acts on each of pressure intensifying operating parts 36, 37 via a pipeline 44, the H location of the electromagnetic switch valve 39 and a pipeline 45. Therefore, relief set pressure of the relief valves 34, 35 is boosted, sudden braking force works on a revolving motor 3 and sudden stop of revolution in an emergency can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling turning of a hydraulic working machine in a construction machine, a working vehicle or the like.

[0002]

2. Description of the Related Art FIG. 2 is a side view of a hydraulic excavator in an upper swing type construction machine. In the figure, 1 is a lower traveling body of a hydraulic shovel, 2 is an upper rotating body, 3 is an upper rotating body 2
The work attachment YY ′ mounted on the front part of the upper revolving unit 2 is a center of rotation. In the case of a hydraulic excavator, work may be performed by attaching a swing type crusher having a swing motor, a swing type grapple, etc. (not shown) to a work attachment.
FIG. 3 is a circuit diagram of a conventional swing motor of a hydraulic excavator. In the figure, 3 is a swing motor, 5 and 6 are anti-cavity check valves for preventing cavitation, respectively, and relief valves 7 and 8 connected to the forward and reverse rotation ports 1 and 2 of the swing motor 3, respectively. Pilot switching valves 10 and 11 for controlling the rotation direction of the motor are holding check valves for preventing high-pressure oil backflow from the rotary motor 3, 12 and 13 are main pumps, 14 is a pilot pump, and 15 and 16 are pilot pumps. Is a directional control valve for other various hydraulic actuators (not shown), 17
Is a center bypass return oil passage, 18 is a center bypass return oil passage, 19 is a turning remote control valve, 20 is an operation lever of the remote control valve 19, 21 is a shuttle valve for selecting a turning pilot pressure, and 22 is an oil tank.

Next, a conventional swing motor circuit will be described with reference to FIG. Relief valves 5 and 6 are connected to the forward and reverse rotation ports I and B of the swing motor 3, respectively. Here, when the operation lever 20 of the remote control valve 19 is operated from the neutral position to the position C or the position D, the pilot pressure from the pilot pump 14 passes through the remote control valve 19 and the pilot pressure receiving portion 2 of the turning pilot switching valve 9.
Acts on 4 or 25. At the same time, shuttle valve 21
The swirling pilot pressure derived from the above acts on the pilot pressure receiving portion 27 of the on-off valve 18. Then, while the turning pilot switching valve 9 is switched to the E position or the F position,
The on-off valve 18 is switched to the oil path shutoff position. Accordingly, the pressure oil from the main pump 12 passes through the oil passages 28 and 29, the check valve 30, the oil passages 31, 32, and 33, the holding check valve 10 or 11, and the turning pilot switching valve 9 in the E position or the F position. It is supplied to the swing motor 3. Therefore, since the turning motor 3 rotates forward or backward,
The upper swing body (2) of the hydraulic excavator performs a swing operation.

[0004]

The operating pressure of the swing motor is limited by the relief setting pressure set in the relief valve, and the brake can be operated by the relief valve when the swing motor is stopped.

However, since the weight of the upper swing body for construction machines is large, its inertia force is also large. Here, if the relief setting pressure of the relief valve is set to a high pressure, the braking force will suddenly act against the inertia force of the upper revolving unit when the turning is stopped, so that the driver's feeling of turning operation becomes uncomfortable. At the same time, the useful life of an internal gear of a rotation speed reducer (not shown) connected to the rotation motor is shortened. Therefore, the relief set pressure of the relief valve is set to a relatively low pressure. Therefore, the turning can be stopped smoothly, but when an emergency involving danger occurs during the turning, the turning cannot be stopped suddenly even if a so-called reverse lever operation is performed to reverse the turning motor.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a turning control method capable of performing an emergency stop during turning.

[0007]

A revolving body, a revolving motor for revolving the upper revolving body, a revolving motor circuit having a relief valve for releasing high-pressure oil when the revolving motor is stopped, and A hydraulic operating machine having a turning operation lever for instructing a turning direction of the revolving unit, wherein the turning operation lever turns the upper revolving unit in the other direction when the upper revolving unit is turning in one direction. The relief set pressure of the relief valve is increased only when operated in the direction in which the relief valve is operated.

The operation of the present invention is as follows. During operation of the swing motor, when the swing operation lever is operated in a predetermined direction with respect to the swing direction of the swing motor, no command signal is output from the controller, and the relief set pressure does not change. B. When the swing operation lever is operated in the direction in which the upper swing body turns in the opposite direction to the swing direction of the upper swing body during operation of the swing motor, a command signal is output from the controller, and the relief setting of the relief valve is performed. Since the pressure is increased, the relief operation is not performed until the pressure in the return pipe of the swing motor rises to the boosted pressure when the swing is stopped. That is, a sudden braking force is applied to the turning motor, and the turning can be stopped suddenly in an emergency.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a circuit diagram showing a turning control device according to the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology. Reference numerals 34 and 35 denote relief valves, reference numerals 36 and 37 denote pressure-increasing operating portions of the relief valves 34 and 35, 38 a pilot pressure source, 39 an electromagnetic switching valve, and 40 an electromagnetic switching valve 3.
9 is a solenoid, 41 is a potentiometer provided on the swing motor 3 ', 42 is an operation lever 20' of the remote control valve 19 '.
Is a potentiometer, and 43 is a controller.

Next, the configuration of the turning control device according to the present invention will be described with reference to FIG. Relief valves 34, 35 are provided with pressure-increasing operating portions 36, 37, respectively.
6, 37 and a pilot pressure source 38 were connected via an electromagnetic switching valve 39. A potentiometer 4 is used as a turning motor rotation detecting means for detecting the turning direction of the turning motor 3 '.
1 and a potentiometer 42 as lever angle detecting means for detecting the tilt direction of the operation lever 20 'of the turning remote control valve 19'. Signals from the potentiometers 41 and 42 are transmitted to the controller 43, respectively.
And the controller 43 outputs a command signal to the electromagnetic switching valve 39.
When the operation lever 20 'is operated in a predetermined direction with respect to the turning direction of the swing motor 3' during the operation of the swing motor 3 ', the relief set pressure of the relief valves 34 and 35 is not changed, When the operating lever 20 'is operated in a direction opposite to the neutral position of the operating lever 20' with respect to the turning direction of the turning motor 3 ', the relief valve 34,
By applying a pilot pressure to the pressure-increasing operation portions 36 and 37 of the respective 35, the relief set pressure of the relief valves 34 and 35 is increased.

Next, the function and function of the turning control device according to the present invention will be described. When the swing lever 3 ′ is operated by operating the operation lever 20 ′, a swing motor rotation detection signal from the potentiometer 41 and a lever angle detection signal from the potentiometer 42 are input to the controller 43. Here, for the sake of explanation, when the operation lever 20 'is operated in the direction C' from the neutral position, the swing motor 3 'rotates forward and the operation lever 20' is rotated in the direction D 'in the neutral position. It is set that the turning motor 3 'performs reverse rotation when the operation is performed. If the operation lever 20 'is operated in the range of the position C' from the neutral position while the swing motor 3 'is rotating forward, a command signal is output from the controller 43 to the solenoid 40 of the electromagnetic switching valve 39. Not done. Since the electromagnetic switching valve 39 remains in the shutoff oil passage position G, the pilot pressure from the pilot pressure source 38 does not act on the pressure-increasing operation sections 36 and 37 of the relief valves 34 and 35. That is, in the above case, the relief set pressure of the relief valves 34 and 35 does not change.

However, when performing a sudden stop while the rotation motor 3 'is rotating forward, the operation lever 20' is operated in a range from the neutral position to the position d '. That is, when performing a sudden turning stop, a so-called reverse lever operation is performed. In that case, the controller 43 uses the potentiometer 4
A command signal is output to the solenoid 40 of the electromagnetic switching valve 39 based on the rotation motor rotation detection signal and the lever angle detection signal from the solenoid valves 1 and 42, respectively. Since the solenoid 40 is energized, the electromagnetic switching valve 39 switches from the shutoff oil passage position G to the open oil passage position H. The pilot pressure from the pilot pressure source 38 acts on the pressure-increasing operation parts 36 and 37 via the pipe 44, the tie position of the electromagnetic switching valve 39, and the pipe 45. Therefore, since the relief set pressure of the relief valves 34 and 35 is increased, the relief operation is not performed until the pressure of the return line of the swing motor 3 ′ rises to the increased pressure when the swing is stopped. That is, a sharp braking force is applied to the turning motor 3 ', and the turning can be stopped suddenly in an emergency.

As described above, during the operation of the swing motor 3 ',
When the reverse lever operation is performed to stop the swing suddenly, the relief set pressure of the relief valves 34 and 35 is increased, and the braking force of the swing motor 3 'is increased. This function can be exerted regardless of whether the rotation motor 3 'is operating in the forward or reverse rotation direction.

In the above embodiment, the potentiometer 4
The rotation motor rotation detection signal and the lever angle detection signal from the rotation motors 1 and 42 are input to the controller 43. Instead, the operation circuit (supply / discharge circuit) of the rotation motor 3 'and the pilot of the remote control valve 19' are used instead. It is also possible to provide a pressure sensor (not shown) in each circuit, and to set the pressure signal from each pressure sensor to the controller 43.

[0015]

In the turning control device according to the present invention, when the turning operation lever is operated in a predetermined direction with respect to the turning direction of the turning motor during operation of the turning motor, the relief set pressure of the relief valve is set. Is not changed, so that there is no hindrance to the turning operation during normal operation of the construction machine. However, when an emergency involving danger occurs during the turning operation of the construction machine, the driver operates the reverse lever. At the same time, the relief set pressure of the relief valve of the swing motor circuit is increased, so that a sharp braking force can be applied to the swing motor. As a result, a sudden turning stop in an emergency can be performed, and a disaster or a collision accident can be prevented.

Therefore, in a construction machine, a work vehicle or the like provided with the turning control device according to the present invention, safety during turning operation is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a turning control device according to the present invention.

FIG. 2 is a side view of the hydraulic excavator.

FIG. 3 is a prior art swing motor circuit diagram of a hydraulic excavator.

[Explanation of symbols]

 ········· Swing motor 5,6,34,35 ··· Relief valve 9 ····· Swing pilot switching valve 14 ····· Pilot pump 19,19 ′ ..Remote control valves 20, 20 '.. Operating levers 36,37 ... Pressure increasing operating part 38 ... Pilot pressure source 39 ... Electromagnetic switching valves 41,42 ... Potentiometer 43 ······controller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Uchida Fukuoka Prefecture Chikushino City, Oaza 667-128 (72) Inventor Hiroshi Sato 2-34-11 Uenoyama, Taishiro-ku, Sendai City 2897 Iinuma, Gujogo-cho

Claims (1)

[Claims] A revolving body, a revolving motor for revolving the revolving superstructure, a revolving motor circuit including a relief valve for releasing high-pressure oil when the revolving motor is stopped, and revolving of the revolving superstructure. A swing operation lever for indicating a direction, wherein when the upper swing body is swinging in one direction, the swing operation lever is operated in a direction to swing the upper swing body in the other direction. A turning control method for a hydraulic working machine, wherein the relief set pressure of the relief valve is increased only when the pressure is set.