JPH041334A - Slewing controller for oil-pressure operation machine - Google Patents

Abstract

PURPOSE:To raise the safety of slewing operation by a method in which during the operation of a slewing motor, the operating direction of a slewing operation lever for the slewing direction of a slewing motor is interlocked with command signals from a controller to a solenoid switch valve. CONSTITUTION:When an operating lever 20' is operated to actuate a slewing motor 3', slewing motor rotation detected signals from a potensiometer 41 and lever angle detected signals from a potensiometer 42 are put in a controller 43. Also, when the operating lever 20' is operated from neutral position to (a) position side, the slewing motor 3' turns normally. When the lever 20' is operated from neutral position (b) side, the motor 3' turns reversely by setting it up. Also, when the motor 3' is abruptly stopped during normal rotation, the lever 20' is operated toward neutral position (b) side, the setting pressures of relief valves 34 and 35 are raised.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a swing control device for a hydraulic working machine in a construction machine, work vehicle, or the like.

BACKGROUND OF THE INVENTION FIG. 2 is a side view of a hydraulic excavator among upper swing type construction machines. In the figure, 1 is a lower traveling body of a hydraulic excavator, 2 is an upper rotating body, 3 is a swing motor disposed on the upper rotating body 2, and 4 is a work attachment Y-Y' attached to the front part of the upper rotating body 2. is the center of rotation. In addition, in the hydraulic excavator, work may be carried out by attaching a rotating crusher having a rotating motor, a rotating grapple, etc. (not shown) to the work attachment. FIG. 3 is a circuit diagram of a conventional swing motor for a hydraulic excavator. In the figure, 3 is a swing motor, 5 and 6 are relief valves 7 connected to the forward rotation and reverse rotation side ports, and ports of the swing motor 3, respectively.
8 are anti-cavity check valves for preventing cavitation, 9 are swing pilot switching valves for controlling the rotation direction of the swing motor 3, and 10 and 11 are holding check valves for preventing high-pressure oil backflow from the swing motor 3, respectively. , 12.13 are the main pumps, 14 are the pilot pumps, 15.16 are directional control valves for other various hydraulic actuators (not shown), 17 is the center bypass return oil passage, and 18 is the center bypass return oil passage 1.
7.19 is a remote control valve for swing; 20 is a control lever 21 of the remote control valve 19; a shuttle valve for selecting the swing pilot pressure; and 22 is an oil tank.

Next, a prior art swing motor circuit will be described with reference to FIG. Relief valves 5 and 6 are connected to the forward and reverse rotation ports and mouth of the swing motor 3, respectively. When the operating lever 20 of the remote control valve 19 is operated from the neutral position to the C position or the third position, the pilot pressure from the pilot pump 14 is transferred to the pilot pressure receiving part 24 of the swing pilot switching valve 9 through the remote control valve 19. or 25. At the same time, the swing pilot pressure derived from the shuttle valve 21 is transferred to the pilot pressure receiving portion 2 of the on-off valve 18.
7. Then, the swing pilot switching valve 9 is switched to the water position or the forward position, and the on-off valve 18 is switched to the oil passage blocking position.

Thereby, the pressure oil from the main pump 12 is transferred to the oil passage 28.
29, check valve 30, oil passage 31, 32, 33, holding check valve 10 or 11, and the water position or backward position of the swing pilot switching valve 9, and are supplied to the swing motor 3. Therefore, since the swing motor 3 rotates forward or backward, the upper rotating body (2) of the hydraulic excavator performs a swing operation.

Problems to be Solved by the Invention The operating pressure of the swing motor is limited by the relief setting pressure set in the relief valve, and when the swing motor is stopped, the brake can be applied by the relief valve.

However, since the weight of the upper revolving body for construction machinery is large, its inertial force is also large. If the relief setting pressure of the above-mentioned relief valve is set to a high pressure, the braking force will be applied suddenly against the inertia of the upper rotating body when turning stops, making the driver's turning operation feel uncomfortable. At the same time, a swing reducer (not shown) connected to the swing motor
This shortens the service life of the inner gear. For this reason, the relief setting pressure of the relief valve is set to a relatively low pressure. Therefore, stopping when turning can be done smoothly, but when a dangerous emergency occurs during turning, even if a so-called reverse lever operation is performed to reverse the turning motor, it is not possible to bring the turning to a sudden stop.

The object of the present invention is to solve the above-mentioned problems and provide a turning control device that can perform an emergency stop when turning.

Means for Solving the Problems The means of the present invention taken to solve the above problems are as follows: (a) A pressure increase is applied to the relief valve disposed to apply a braking force when the swing motor is stopped. An actuating part is provided, and the pressure increasing actuating part and the pilot pressure source are connected via an electromagnetic switching valve, c. A swing motor rotation detection means for detecting the swing direction of the swing motor, and a swing operation lever. A lever angle detecting means for detecting the tilting direction is provided, and two, signals from the swing motor rotation detecting means and the lever angle detecting means are input to the controller, and a command signal is outputted from the controller to the electromagnetic switching valve. , E. When the swing operation lever is operated in a predetermined direction with respect to the swing direction of the swing motor while the swing motor is operating, do not change the relief setting pressure of the relief valve. When the swing control lever is operated in the direction opposite to the neutral position of the control lever in the swing direction, the relief setting pressure of the relief valve is increased by applying pilot pressure to the pressure increase operation part of the relief valve. It was configured to boost the pressure.

Operation A. 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 to the electromagnetic switching valve. Since the electromagnetic switching valve remains in the shutoff oil path position, the pilot pressure from the pilot pressure source does not act on the pressure increase operation section of the relief valve. That is, the relief set pressure does not change in the above case.

During operation of the swing motor, if the swing operation lever is operated in the direction opposite to the neutral position of the control lever in the direction of rotation of the swing motor, a command signal is output from the controller to the electromagnetic switching valve. Ru. Since the electromagnetic switching valve is switched to the open oil passage position, pilot pressure from the pilot pressure source acts on the pressure increasing operation portion of the relief valve via the electromagnetic switching valve. Therefore, since the relief set pressure of the relief valve is increased, the relief operation is not performed until the pressure in the return line of the swing motor increases to the increased pressure when the swing is stopped.

In other words, a sudden braking force acts on the swing motor, making it possible to suddenly stop the swing in an emergency.

Embodiments Hereinafter, embodiments of the present invention will be described 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 the same components as in the prior art. 34, 35 are relief valves, 36, 37 are pressure increasing operation parts of the relief valves 34, 35, 38 are pilot pressure sources, 3.9
4 is a solenoid switching valve, 40 is a solenoid of the electromagnetic switching valve 39,
1 is a potentiometer provided on the swing motor 3', 42 is a potentiometer provided on the operating lever 20' of one remote control valve, and 43 is a controller.

Next, the configuration of the swing control device according to the present invention will be described with reference to FIG. Each of the relief valves 34 and 35 was provided with a pressure increase operation section 36 and 37, and the pressure increase operation section 36 and 37 were connected to a pilot pressure source 38 via an electromagnetic switching valve 39. Further, a potentiometer 41 is used as a rotation motor rotation detection means for detecting the rotation direction of the rotation motor 3', and a potentiometer 42 is used as a lever angle detection means for detecting the tilting direction of the operating lever 20' of the rotation remote control valve 19'.
Each was equipped with the following. Also, potentiometer 41.
42 are input to the controller 43, and from the controller 43 the above-mentioned electromagnetic switching valve 3 is inputted.
A command signal is now output for 9. When the operating lever 20' is operated in a predetermined direction with respect to the rotating direction of the rotating motor 3' during operation of the rotating motor 3', the relief setting pressure of the relief valves 34 and 35 is not changed; Furthermore, when the operating lever 20° is operated in a direction opposite to the neutral position of the operating lever 20° with respect to the rotating direction of the swing motor 3', the pilot pressure is The relief set pressure of the relief valves 34 and 35 is increased by acting on the relief valves 34 and 35.

Next, the functions of the swing control device according to this invention will be described. Operate the operating lever 20' to turn the swing motor 3'.
When the controller 43 is operating, a rotation motor rotation detection signal from the potentiometer 41 and a lever angle detection signal from the potentiometer 42 are input to the controller 43.

For convenience of explanation, the swing motor 3'' rotates forward when the operating lever 20' is operated from the neutral position toward the high position, and the operating lever 20' is moved toward the neutral position 2' position. The swing motor 3' is set to rotate in reverse during operation.When the swing motor 3' is rotating forward, operate the operating lever 20' within the range from the neutral position to the C position. If so, no command signal is output from the controller 43 to the solenoid 40 of the electromagnetic switching valve 39.Since the electromagnetic switching valve 39 remains in the shutoff oil path position 1, the pilot pressure from the pilot pressure source 38 does not act on the pressure increase actuator 36.37 of the relief valve 34.35.That is, in the above case, the relief valve 34.
35's relief setting pressure remains unchanged.

However, if you want to make a sudden stop while the swing motor 3' is rotating in the forward direction, operate the operating lever 20'' from the neutral position to the 2' position. The lever is operated. In this case, the controller 43 outputs a command signal to the solenoid 40 of the electromagnetic switching valve 39 based on the swing motor rotation detection signal and lever angle detection signal from the potentiometers 41 and 42, respectively.The solenoid 40 is energized. Therefore, the electromagnetic switching valve 39 switches from the cut-off oil passage position G to the open oil passage position H. The pilot pressure from the pilot pressure source 38 is
Via the pipe 44, the position of the electromagnetic switching valve 39, and the pipe 45,
They act on pressure increase actuators 36 and 37, respectively. Therefore, since the relief set pressure of the relief valves 34 and 35 is increased, the relief operation is not performed until the pressure in the return line of the swing motor 3' increases to the above-mentioned increased pressure when the swing is stopped. Sudden braking force is applied and it is possible to perform a sudden turning stop in an emergency.4 As mentioned above, when the reverse lever is operated to make a sudden turning stop while the swing motor 3' is operating, the relief valve 34.35
The relief set pressure of the rotation motor 3 is increased, and the braking force of the swing motor 3 is increased. This effect can be achieved even when the swing motor 3' is operating in either the forward or reverse direction of rotation.

Note that in the above embodiment, the potentiometer 41. .

The swing motor rotation detection signal and lever angle detection signal from 42 are input to the controller 43, but instead, they are input to the operating circuit (supply/discharge circuit) of the swing motor 3'' and the pilot circuit of the remote control valve 19°. It is also possible to provide each with a pressure sensor (not shown) and set the pressure signal from each pressure sensor to be input to the controller 43.

Effects of the Invention In the swing control device according to the present invention, when the swing operation lever is operated in a predetermined direction with respect to the swing direction of the swing motor while the swing motor is in operation, the relief setting pressure of the relief valve is changed. Therefore, there is no problem with the turning operation of the construction machine during normal work. However, if a dangerous emergency occurs when the construction machine turns, the driver operates the reverse lever. At the same time, the relief setting pressure of the relief valve of the swing motor circuit is increased, so that a sudden braking force can be applied to the swing motor. This makes it possible to turn and stop suddenly in an emergency, thereby preventing disasters and collisions.

Therefore, in a construction machine 1 work vehicle or the like equipped with the swing control device according to the present invention, safety during a swing operation is improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a swing control device according to the present invention;
FIG. 2 is a side view of the hydraulic excavator, and FIG. 3 is a circuit diagram of a conventional swing motor of the hydraulic excavator. 3.3' Swing motor 5.6, 34.35------Relief valve 19,
19' 20, 20' 36, 37 Three pilot switching valves for swing Pilot pump --- Remote control valve 1 --- Operation lever Pressure increase actuation section Pilot pressure source Solenoid switching valve Potentiometer controller that's all

Claims (1)

[Claims] (1) In a swing motor circuit equipped with a relief valve that releases high-pressure oil when the swing motor is stopped, the relief valve is provided with a pressure increase operation section, and the pressure increase operation section and the pilot pressure source are electromagnetically switched. A swing motor rotation detection means is connected via a valve and is provided with a swing motor rotation detection means for detecting the swing direction of the swing motor and a lever angle detection means for detecting the tilting direction of the swing operation lever. A signal from the means is input to the controller, and a command signal is output from the controller to the electromagnetic switching valve, and the swing operation lever is moved in a predetermined direction with respect to the swing direction of the swing motor while the swing motor is in operation. When operating the relief valve, the relief setting pressure of the relief valve is not changed, and when the swing operating lever is operated in the opposite direction from the neutral position of the operating lever with respect to the swing direction of the swing motor, the relief valve is 1. A swing control device for a hydraulic working machine, characterized in that the relief setting pressure of a relief valve is increased by applying pilot pressure to a pressure increasing operation section of the hydraulic working machine.