JPH02261907A - Swivel control device of hydraulic shovel or the like - Google Patents

Abstract

PURPOSE:To stop an inertia body smoothly by keeping a directional changeover valve at a minute contact position by means of an output from a controller for a specified period from the time when an output from an operation detector becomes a specified value or lower to the time when the inertia body steps. CONSTITUTION:When a joy stick 7a is operated in the direction of Ra, a directional control valve 2 is switched to the side of a position 2a by an operation control part 25 and an inertial body 6 is driven in a direction of an arrow by means of a hydraulic motor 5. When the joy stick 7a is reset in a neutral position, the directional changeover valve 2 is also reset in a neutral position 2c. The hydraulic motor 4 is, however, a pumping-operated by inertia force of the inertial body 6, hydraulic pressure of a main circuit 3b is increased to actuate a brake valve 8b. When deceleration begins, a signal from an operation detector 21 is input to a stopping control part 26. The rotational speed of the hydraulic motor 5 is then a specified value or lower, and a signal is applied to a solenoid operation part 22b through a contact point S so that the directional changeover valve 2 is kept in a minute contact position for a period long enough to stop the inertia body 6. It is therefore possible to stop the inertia body smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a swing control device for a construction machine such as a hydraulic excavator.

[Prior art] Conventionally, this type of technology is as shown in Fig. 3 (Japanese Unexamined Patent Publication No. 58-1
No. 38837].

This conventional technique will be explained below. In FIG. 5, the directional control valve 2 has one side connected to the discharge side of the hydraulic pump 1 and the tank 4, and the other side connected to the main circuit a
Via the main circuit 3b, a rotating body 6 [a rotating body such as a rotating base of a hydraulic excavator, hereinafter referred to as an inertial body. ] is connected to the hydraulic motor 5 that drives the.

The directional control valve 2 has a neutral position 2C1 switching position 2a switching position 2b, a pilot operating section 2pa, and a pilot operating section 2p.
This pilot operating section 2p a % pilot operating section 2ρb has an output port 7a of the pilot valve 7.
, the output port 7b is connected.

The pilot valve 7 has an operating lever 7e, and when the operating lever 7e is operated to the right, pilot oil pressure corresponding to the operating amount acts on the pilot operating portion 2ρa, and when operating to the left, the operating amount is increased. The configuration is such that a pilot hydraulic pressure corresponding to the amount of pressure is applied to the pilot operating portion 2pb.

The directional control valve 2 is in a switching position 2a or a switching position 2b.
When switching from to neutral position 2C, the meter-in side (
The relationship between the meter-out side (the side that supplies pressure oil to the hydraulic motor) and the meter-out side (the side from which pressure oil is discharged from the hydraulic motor) shows a characteristic curve of the relationship between the stroke of the spool of the directional control valve 2 and the opening area. As shown in the meter-in side curve A and the meter-out side curve B in Fig. 6, the minute connection position 2 is where the meter-out side is minutely connected to the tank 4 after the meter-in side is closed.
It has e. In addition, 88.8b in FIG. 5 is a brake valve, and 9 is a main relief valve.

In the conventional device having the above configuration, when the operating lever 7e of the pilot valve 7 is operated in the right direction, the output port 7a is opened.
Since the pilot oil pressure from 2000 to 2000 is applied to the pilot operating portion 2pa and the directional control valve 2 is switched to the switching position 12a, the hydraulic motor 1 drives the inertial body 6 in the direction of the arrow 6a.

In this driving state, the operating lever 7 of the pilot valve 7
e to hold the spool of the directional control valve 2 at position Bl (fine connection position 2e) in FIG. Then, the supply of hydraulic pressure from the meter-in side main circuit 3a side of the hydraulic motor 5 is cut off, but the meter-out side main circuit 3b side receives a minute amount of pressure oil from the main circuit 3b via the minute connection position 2e. is connected to tank 4. However, since the hydraulic motor 5 is driven by the inertia force of the inertial body 6, the hydraulic pressure of the main circuit 3b is changed to the brake valve 8 as shown in part C1 of the characteristic curve C in FIG.
b is increased to 210 Mgf Cn'', which is the set value of b, and a braking force is applied to the hydraulic motor 5.

During this time, the inertial body 6 is operating in the direction of the operating arrow 6a, as shown in the characteristic curve portion D1.

Even if the inertial body 6 reaches the point D2 (the position where the inertial body stops because the brake valve stops operating and the main circuits are both closed), the main circuit 3b on the meter-out side has 17
5Mgf/Cm” (7) Oil pressure remains.

Since the directional control valve 2 is held at the minute connection position 2e, the oil pressure in the main circuit 3b on the meter-out side is at a portion C.
It descends rapidly as shown in 3. For this reason, the inertial body 6
is not driven in the opposite direction as shown in section D4;
Stop as shown in 3.

(Note that if there is no minute connection position 2e of the directional control valve 2, the oil pressure in the main circuit 3b on the meter-out side will be a high oil pressure as shown in part C4, so the inertial body 6 will be in the opposite position as shown in part D4. It is driven to the side (1 meter back).

) When the inertial body 6 stops in this way, the operating lever 7e
to the neutral position, and move the directional control valve 2 to the minute connection position 1f2.
The inertial body 6 is stopped by operating from e to the neutral position 2c.

[Problem to be solved by the invention]

In the conventional technology described above, when stopping the inertial body 6 from the driving state, it is necessary to operate the directional control valve 2 to hold it at the minute connection position 2e using the operation lever 7e of the pilot valve 7, and then operate it again to the stop position. There is. This operation
Since the time required to hold the minute connection position 2e is short and the operation is achieved by minute operation of the operating lever 7e of the pilot valve 7, skill is required for operation.

Therefore, an object of the present invention is to enable a smooth stopping operation of an inertial body without requiring any skill in the operation.

(Means for Solving the Problems) A first means of the present invention for solving the above problems is to connect the discharge side of the hydraulic pump to a hydraulic motor that drives an inertial body through a directional control valve and a main circuit. and a configuration in which the directional control valve has a minute connection position that connects the hydraulic pressure of the main circuit on the meter-out side to a low pressure side and a neutral position that closes the main circuit when the hydraulic motor is stopped from operating. In a swing control device for a hydraulic excavator or the like, the hydraulic motor or the inertial body is provided with an operation detector for detecting its operation, and the directional control valve is configured to have an electromagnetic operation section, and the electromagnetic operation section and the operation detector A controller is provided between the controller and the controller, and the controller has an output that maintains the directional control valve in the minute connection position for a certain period of time from when the value of the output of the actuation detector becomes below a certain value until the inertial body stops. It is configured to transmit a signal.

A second means connects the discharge side of the hydraulic pump to a hydraulic motor that drives an inertial body via a directional control valve and a main circuit, and connects the directional control valve when the hydraulic motor is stopped from operating. A swing control device for a hydraulic excavator or the like configured to have a minute connection position that connects the hydraulic pressure of the main circuit on the meter-out side to the low pressure side and a neutral position that closes the main circuit,
The hydraulic motor or the inertial body is provided with an operation detector for detecting its operation, the directional control valve is configured to have an electromagnetic operation section, and a controller is provided between the electromagnetic operation section and the operation detector, When the output of the actuation detector becomes less than a certain value, the controller outputs an output signal that maintains the directional control valve in the minute connection position at a constant value corresponding to the differential coefficient of the reduced output of the actuation detector. The structure includes a deceleration detector that transmits time.

The third means is a swing control device such as a hydraulic cylinder, in which the discharge side of a hydraulic pump is connected to a hydraulic motor that drives an inertial body through a direction control valve and a main circuit, and in which the hydraulic motor or the inertial body is controlled to operate. An operation detector is provided for detection, and the main circuit connected to the hydraulic motor is connected by a circuit having a solenoid valve that is switched from a closed position to a minute connection position by the operation of an electromagnetic operation part,
A controller is provided between the electromagnetic operation part of the solenoid valve and the operation detector, and the controller controls the direction for a certain period of time since the inertial body stops after the output of the operation detector becomes less than a certain value. The valve is configured to generate an output signal that maintains the valve in the micro-connected position.

A fourth means is a swing control device such as a hydraulic sysibel in which the discharge side of a hydraulic pump is connected to a hydraulic motor that drives an inertial body through a direction control Ti valve and a main circuit, and the hydraulic motor or the inertial body is operated by the hydraulic motor or the inertial body. an operation detector for detecting the hydraulic motor, and a main circuit connected to the hydraulic motor is connected by a circuit having an electromagnetic valve that is switched from a closed position to a minute connection position by the operation of an electromagnetic operation part,
A controller is provided between the electromagnetic operating section of this electromagnetic valve and the operation detector, and 20tt4? When the output of the actuation detector falls below a certain value, the output signal for holding the directional control valve in the minute connection position is transmitted for a certain period of time according to the differential coefficient of the reduced output of the actuation detector. This configuration includes a deceleration detector that transmits a signal.

[Effect]

According to the present invention having the above configuration, when the output value of the operation detector provided on the hydraulic motor or the inertial body becomes below a certain level,
Since the deceleration detector of the controller holds the directional control valve or solenoid valve in the minute connection position for a certain period of time until the inertial body stops, the inertial body can be swung back without the operator being consciously aware of it. It can be stopped without any problem.

Furthermore, when the output of the actuation detector provided on the hydraulic motor or inertial body falls below a certain value, the deceleration detector of the controller maintains the directional control valve or solenoid valve in the minute connection position. Since the output signal is transmitted for a time corresponding to the differential coefficient of the decreased output of the operation detector, the inertial body can be stopped without swinging back even if the operator is not particularly aware of changes in the inertial force of the inertial body. I can do it.

[Explanation of Examples]

Below, Fig. 1 shows the first embodiment, and Fig. 2 shows the second embodiment.
The present invention will be explained in detail with reference to the figures.

In addition, in the description, the same numbers are given to the same components as those in the conventional technology, and the description thereof will be omitted.

In FIG. 1 showing the first embodiment, the directional control valve 2 includes an electromagnetic operating section 22a that is operated by a signal from a controller 20.
, 22b.

The controller 20 is connected to the output side of the joystick 7a, and outputs an operation control section 25 that sends an operation signal to the electromagnetic operation sections 22a and 22b of the directional control valve 2, and an operation detector 21 that detects the rotation speed of the hydraulic motor 5. This configuration includes a stop operation control section 26 that generates a signal when the power decreases.

The operation control section 25 includes an amplifier 25a that amplifies the command value from the joystick 7a, a switch 25b that outputs a switching signal for the switch 25d based on the output (+) (-) of the amplifier 25a, and an output of the amplifier 25a. It is comprised of an adder 27 that adds the output of the stop operation II control section 26, and a function converter 25c that converts the output of the adder 27 into a predetermined function.

The stop operation control unit 2G detects that the output signal of the operation detector 21 starts to decrease and the rotation speed of the brake valve 8a,
8b When the rotational speed reaches a certain value when activated, the deceleration detector 26 activates and transmits an output signal TO, and holds this output signal To at L1 for a sufficient period of time for the inertial body to stop.
a and when this output signal TO is applied, the operation control unit 2
The adder 27 of No. 5 has a regulator 26c that outputs an actuation signal (3) that maintains the directional control valve 2 at the minute connection position 2e.

The operation of this embodiment will be described below.

When the handle 7b of the joystick 7a is moved in the left direction Ra, the amplifier 25a of the operation control unit 25 sends the output of -Vl to the function converter 25c via the switch 25b and the adder 27 in accordance with the amount of raking. Apply. The switch 25b is
A signal is applied to switch 25d to switch the output side of function converter 25c to contact Sa. For this reason, the direction control valve 2
The electromagnetic operation section 22a has a function -■ of the function converter 25c.
2 is applied. This signal to the electromagnetic operating section 22a causes the directional control valve 2 to move to the switching position 2.
The hydraulic motor 5 drives the inertial body 6 in the direction of the arrow 6a.

In this way, when the handle 7b of the joystick 7a is returned to the neutral position while the inertial body 6 is being driven in the direction of the arrow 6a, the signal from the joystick 7a disappears, so the directional control valve 2 returns to the neutral position 2c. . However, although the hydraulic motor 5 attempts to continue rotating in the direction of the arrow 6a due to the inertia of the inertial body 6, the directional control valve 2 returns to the neutral position 2c, and both the main circuits 3a and 3b are closed. Therefore, the hydraulic motor 5 is pumped by the inertial force of the inertial body, and the pressure oil discharged from the hydraulic motor 5 is sent to the main circuit 3b on the meter-out side, and the oil pressure in the main circuit 3b increases.

This oil pressure in the main circuit 3b is controlled by the brake valve 8b as shown in section C1 in FIG. 7, so that a braking force acts on the hydraulic motor 5. When a brake force is applied to the hydraulic motor 5, the rotation speed of the hydraulic motor 5 starts to decrease from 0 rotation speed as shown in FIG.
is detected and applied to the stop operation control section 26 of the controller 20. When the rotation speed of the hydraulic motor 5 decreases below a certain value, the stop operation control unit 26 applies one output signal to the regulator 26c for a sufficient period of time for the inertial body 6 to stop. This regulator 26c output signal v3 is applied to the function converter 25c via the adder 27, and changes the value of the output V3' that holds the directional control valve 2 at the minute connection position W, 2e to the switch 25d.
The voltage is applied to the electromagnetic operating portion 22a of the directional control valve 2 through the contact Sa. For this reason, the directional control valve 2 has a spool in the sixth position.
It is operated to the B1 position shown in the figure.

[It is operated to the minute connection position 2e. ] When the directional control valve 2 is operated to the minute connection position 2e,
Since the main circuit 3b is connected to the tank 4 through the minute throttle, at point C2 in FIG. 7, where the brake valve 8b stops operating, the oil pressure in the main circuit 3b on the meter-out side is As shown in part C3 of the figure, the inertia body 6 stops without swinging back because it rapidly decreases and is not accumulated in the main circuit 3b.

When the output signal of the deceleration detector 26a of the stop operation control section 26 is generated for t1 time, the transmission of the output signal TO is stopped, so all signals to the electromagnetic operation section 22 are cut off, and the directional control valve 2 is , neutral position! Return to 2c and main circuit 3a,
Block 3b.

Therefore, the inertial body 6 is held at the stop position.

In the above-mentioned embodiment, as shown in FIG. 4(A), the deceleration detector 26a detects a period of time L1'' during which the hydraulic motor 5 stops from Tl immediately after the hydraulic motor 5 starts decelerating.
It applies an actuation signal to the electromagnetic operation section 22. However, as shown in FIG. 4 CB), the deceleration detector 26a detects that the rotational speed of the hydraulic motor 5 has reached a point near T3 (the value of T3 is, for example, when the brake valve stops operating). A structure may also be adopted in which the output signal To is transmitted at the time, and the time tl' required for the hydraulic motor 5 to stop is transmitted from that time.

Furthermore, as another embodiment, a differentiation function is added to the deceleration detector 26a to differentiate the decrease in the rotation speed of the hydraulic motor 5,
According to this differential value, the output signal T of the deceleration detector 20a is
The length of the output time tl of O may be determined. This output time t1 will be explained below.

In FIG. 3, the value of the rotation speed of the hydraulic motor 5 that can be measured by the operation detector 21 is set as NO, and the time from when the hydraulic motor 5 reaches this rotation speed No. until it stops is set as Δt1. Further, assuming that the rate of deceleration of the hydraulic motor 5 is approximately constant, it becomes No/At 1-dN/d t□■ [N is the number of rotations of the hydraulic motor].

From the formula ■, ΔL1 is Therefore, the output time B length is Ll-Δt1+α□■ (α is the sufficient time for the hydraulic motor 5 to stop and ΔL
IX(2-3).

According to this means of determining the rotational speed NO or the output time t1, as the inertial load increases, the value of the differential coefficient decreases, so the output time t1 increases by that amount, and the output time tl corresponding to the inertial force of the inertial body increases. Since it can be set, the inertial body can be stopped without swinging back regardless of fluctuations in inertial force.

Next, a second embodiment of the present invention will be described with reference to FIG.

The difference between the first embodiment and the second embodiment described above is that the first embodiment provides a small connection value r112e for the directional control valve 2, whereas the second embodiment provides a small connection value r112e for the directional control valve 2. A circuit 3 equipped with a small electromagnetic valve 30 configured to have, between the main circuit 3b, a closing position 31b that closes the electromagnetic operation part 32 and the circuit 31, and a minute connection position 3La that connects the circuit 31 with a minute restriction.
1, and the direction 1tlIII valve 2 is a normal direction vfAm valve without the minute connection position 2C.

In addition, since the directional control valve 2 is a hydraulic pilot operated type, the controller 20 is configured with only the stop operation control section 26, and the output side of the deceleration detector 26a is connected to the electromagnetic operation of the small electromagnetic valve 30. It is connected to the section 32.

The second embodiment having the above configuration is shown in FIG.
Operate the operating lever 7e of the pilot valve 7 to operate the directional control valve 2 to the switching position 2a, and when the hydraulic motor 5 drives the inertial body 6 in the direction of the arrow 6a, return the operating lever 7e to the center position,
Assume that the directional control valve 2 returns to the neutral position W2c. Then, both the main circuits 3a and 3b are closed at the neutral position 2C, so the oil pressure in the main circuit 3b on the meter-out side rises to the set value of the brake valve 8b, as shown in part C1 of FIG. A brake is applied to the hydraulic motor 5.

When the brake is applied to the hydraulic motor 5, its rotational speed decreases, and when the inertial body 6 begins to decelerate, the deceleration detector 26
Since the output signal To is applied to the small electromagnetic valve 30 from a, the small electromagnetic valve 30 is switched to the minute connection position 31a and held for a time t1. Therefore, the main circuits 3a and 3b are connected via the circuit 31. For this reason,
The hydraulic pressure in the main circuit 3b just before the rotation of the hydraulic motor 5 decreases and the inertial body 6 is about to stop is released to the low pressure side through the small throttle of the small solenoid valve 30, so that the inertial body 6 shakes. Stops without any return.

When the time L1 ends, the activation signal to the electromagnetic operation section 22 of the small electromagnetic valve 30 stops. Therefore, the small solenoid valve 30 is switched to the closed position 31b, and the main circuits 3a, 3
Close the space between b.

Note that the above embodiment also includes a differentiator in the deceleration detector 26a, and the differentiator differentiates the decrease in the rotational speed of the hydraulic motor 5, and the output time L of the output signal TO is determined according to the differential coefficient.
1 may be changed.

[Effects of the Invention] The present invention provides a hydraulic motor or an inertial body with an operation detector for detecting its operation, and also configures a control valve to act as an electromagnetic operation section, and the electromagnetic operation section and the operation detector are connected to each other. A controller B is installed in between, and when the output value of the actuation detector falls below a certain value, the controller B outputs an output signal that maintains the control valve in the minute connection position until the inertial body stops. Since it is configured with a deceleration detector that transmits time, delicate operations to prevent back-spreading when the inertial body is stopped can be performed easily.
This is done automatically by the III controller.

Therefore, even if the operation of the construction machine is inexperienced, the inertial body can be stopped smoothly.

In addition, when the output of the actuation detector becomes below a certain level, the fiill device is configured to transmit an output signal for holding the control valve in a minute connection position for a certain period of time corresponding to the differential coefficient of the decrease in the output of the actuation detector. Since it has a configuration with a speed detector,
Changes in the inertial force of an inertial body (When a construction machine is stopped on a slope and works, the inertial force differs depending on whether the rotating body turns upward or downward. and when the boom is extended, when it is retracted, or
It also changes when the packet is filled with soil and when it is empty. ), the controller automatically performs delicate operations to prevent the inertial body from swinging back when it is stopped. In addition, since the output time is set to a constant time according to the differential coefficient, the output time is determined according to changes in the inertial force, so the main circuit is closed almost at the same time as the hydraulic motor stops, so the inertial body can be stopped accurately. . Therefore, even if the operator of the construction machine is inexperienced, the inertial body can be stopped smoothly.

Furthermore, the electromagnetic control valve having the minute connection position may be a solenoid valve that allows a minute amount of oil to pass through, so it can be configured to be extremely compact. Therefore, existing construction machinery can be easily improved.

It also has the advantage of being easy to incorporate into a hydraulic motor.

[Brief explanation of drawings]

Figure 1 is a hydraulic circuit diagram of the first embodiment of the present invention, Figure 2 is a hydraulic circuit diagram of the second embodiment of the present invention, and Figure 3 is the hydraulic pressure when applying the brake to the hydraulic motor. A characteristic curve diagram showing changes in the rotation speed of a motor. 4(A) and 4(B) are explanatory diagrams of the operating status of the control valve, and FIG. 5 is a hydraulic circuit diagram of the prior art.
Figure 6 is a characteristic curve diagram showing the relationship between the spool operation amount and opening area, and Figure 7 is a characteristic curve diagram showing changes in the oil pressure on the meter-out side with respect to time and a characteristic curve diagram of the displacement of the inertial body. be. 1...Hydraulic pump 2...Direction $ control valve 2e, 31a...Minute connection position 3a, 3b = Main circuit 4...Tank 5...Hydraulic motor 6...Inertia body 8a, 8b" - Brake valve 20... Controller 21a, 21b = Pressure detector 22a, 22b, 32 - Electromagnetic operation section 26... Stop operation control section 26a... Deceleration detector TO-... Deceleration detector 2 (ia output signal LL-・
Output time of output signal TO 30...Small solenoid valve 31...Circuit 31 a = minute connection position 3 l b-...closed position. Patent applicant: Japan Air Brake Co., Ltd. Kobe Steel, Ltd.

Claims (4)

[Claims] (1) Connect the discharge side of the hydraulic pump to the hydraulic motor that drives the inertial body through the directional control valve and the main circuit, and connect the directional control valve to the meter-out side when the hydraulic motor is stopped from operating. In a swing control device for a hydraulic excavator or the like configured to have a minute connection position that connects the hydraulic pressure of the main circuit to the low pressure side and a neutral position that closes the main circuit, the operation of the hydraulic motor or the inertial body is detected. In addition to providing an operation detector, the directional control valve is configured to have an electromagnetic operation section, a controller is provided between the electromagnetic operation section and the operation detector, and the controller is configured to adjust the value of the output of the operation detector. A swing control device for a hydraulic excavator, etc., configured to transmit an output signal to hold the directional control valve in a micro-connection position for a certain period of time after the inertial body stops after the inertial body becomes less than a certain value. (2) Connect the discharge side of the hydraulic pump to the hydraulic motor that drives the inertial body via the directional control valve and the main circuit, and connect the directional control valve to the meter-out side when the hydraulic motor is stopped from operating. In a swing control device for a hydraulic excavator or the like configured to have a minute connection position that connects the hydraulic pressure of the main circuit to the low pressure side and a neutral position that closes the main circuit, an operation that detects the operation of the hydraulic motor or an inertial body is provided. In addition to providing a detector, the directional control valve is configured to have an electromagnetic operation section, a controller is provided between the electromagnetic operation section and the operation detector, and the controller is configured to prevent a decrease in the output of the operation detector. Swing control for a hydraulic excavator, etc., configured to transmit an output signal for holding the directional control valve in a minute connection position for a certain period of time according to the differential coefficient of the output of the operation detector when the value falls below a certain value. Device. (3) In a swing control device for a hydraulic excavator, etc., in which the discharge side of a hydraulic pump is connected to a hydraulic motor that drives an inertial body via a directional control valve and a main circuit, the operation of the hydraulic motor or the inertial body is detected. An operation detector is provided, and the main circuit connected to the hydraulic motor is connected by a circuit having an electromagnetic valve that is switched from a closed position to a minute connection position by the operation of an electromagnetic operating section, and the electromagnetic operating section of the electromagnetic valve and A controller is provided between the actuation detector, and the controller controls the directional control valve to a minute connection position for a certain period of time from when the output value of the actuation detector becomes less than a certain value until the inertial body stops. A swing control device for a hydraulic excavator, etc., configured to send out an output signal that is maintained at the same time. (4) In a swing control device for a hydraulic excavator or the like in which the discharge side of a hydraulic pump is connected to a hydraulic motor that drives an inertial body through a direction control valve and a main circuit, an operation that detects the operation of the hydraulic motor or the inertial body. A detector is provided, and a main circuit connected to the hydraulic motor is connected by a circuit having an electromagnetic valve that is switched from a closed position to a minute connection position by the operation of an electromagnetic operating section, and the electromagnetic operating section of this electromagnetic valve and the above-mentioned A controller is provided between the actuation detector, and when the output of the actuation detector becomes less than a certain value, the actuation detector outputs an output signal that holds the directional control valve in the minute connection position. A swing control device for a hydraulic excavator, etc., configured to transmit a signal for a certain period of time according to the differential coefficient of the output of the excavator.