KR100240081B1 - A relief pressure variable control device of revolutionary motor for heavy equipment - Google Patents

Abstract

The present invention relates to a hydraulic control device for a swing motor for heavy equipment, and in particular, by varying the relief pressure of the swing motor in a variety of hydraulic construction heavy equipment, including excavators, the response of the work device and the swing can be improved and first of all A device is provided so that a function can be secured. The apparatus according to the present invention includes a flow path provided between the pilot pump and the back pressure side of the relief valve of the swing motor, a solenoid flow path opening and closing valve installed in the flow path to open / close the flow path according to a predetermined electrical signal; A control unit for receiving a pressure signal value of the pressure switch and applying a predetermined electrical signal to the flow path opening and closing valve by a predetermined control operation is provided.

Description

Variable relief pressure control device of heavy duty swing motor

1 is a hydraulic circuit diagram of a conventional heavy equipment.

2 is a hydraulic circuit diagram of heavy equipment to which a variable relief pressure control device for a swing motor according to an embodiment of the present invention is applied.

* Explanation of symbols for main parts of the drawings

P1, P2: first and second hydraulic pump P3: pilot pump

1, 3, 5: Actuator 7: Main control valve

7a, 7b, 7c: Control valves 11, 13, 15: Pilot flow path

21a, 21b: Slewing motor relief valve 31, 33, 35: Pressure switch

37: flow path 39: flow path opening and closing valve

41: control unit

The present invention relates to a hydraulic control device for a swing motor for heavy equipment, and in particular, by varying the relief pressure of the swing motor in various hydraulic construction heavy equipment including an excavator, the response of the work device and the swing can be improved and first of all A device is provided so that a function can be secured.

1 shows a hydraulic circuit of a conventional heavy equipment.

As shown, the hydraulic circuit of the heavy equipment is operated by the first and second hydraulic pumps P1 and P2 driven by the engine E / G and the discharge flow rates of the hydraulic pumps P1 and P2. It is installed between the plurality of actuators (101, 103, 105) and the hydraulic pump (P1, P2) and the actuators (101, 103, 105) to selectively apply the discharge flow rate of the hydraulic pump (P1, P2) to the actuators (101, 103, 105) and their operation and It consists of main control valve (107: MCV) that controls the operation direction.

The plurality of actuators described above may include left and right traveling motors, swing motors, boom cylinders, arm cylinders, bucket cylinders, and the like, among which only the swing motor 101, the arm cylinder 103, and the boom cylinder 105 are illustrated. I will explain.

On the swing motor 101 side, two relief valves 109a and 109b are provided for setting the operating pressure of the swing motor.

By the way, in the conventional hydraulic circuit as described above, in the case of various operations of the excavator related to the swinging operation, that is, the loading operation and the swinging operation and the arm-outing operation combined with the turning operation and the buoy-up operation, There were problems in flow rate distribution and workability.

That is, in the case of the loading operation, when the set pressure of the relief valves 109a and 109b of the swing motor 101 is set high, a large torque is generated in the swing motor 101 and the swing speed is increased compared to the pour-up speed. Is so fast that workability and safety are significantly reduced. Therefore, in consideration of the loading operation such as the turning operation and the boolean up operation, the above-mentioned setting pressures of the relief valves 109a and 109b should be set low. In this case, the turning operation and the arm out operation are combined. When performing work, the two actuators (swinging motor 101 and the arm cylinder 103) are operated by the same pump (second hydraulic pump P2), and the load pressure of the arm out is applied to the turning motor 101. Since the flow rate is much larger than that, most of the flow rate flows only to the turning motor 101 side, and the flow rate hardly flows to the arm cylinder 103 side, thereby significantly reducing workability.

As a result, in various operations involving the combined operation of the swing motor 101 and the other actuators, the requirements for each operation are different, so that the relief valves 109a and 109b of the fixed swing motor 101 are set. In the case of the conventional pressure, it was impossible to find the optimum relief set pressure according to various operations, thereby reducing the workability and safety of the excavator as a whole.

Accordingly, it is an object of the present invention that the set pressure of the relief valve of the swing motor is variably controlled to an optimum state according to the work type and the work requirements, thereby improving the responsiveness of the actuator and the operability at the time of combined operation. It is an object of the present invention to provide an apparatus for obtaining improved workability and safety in an excavator.

The object of the present invention described above is to control at least one pump, a plurality of actuators including a swing motor actuated by the pump, and a flow path switching connection by operating the actuator and the direction of operation of each of the actuators. It is applied to the hydraulic device of heavy equipment having a plurality of control valves; A plurality of pressure switches installed in a pilot pump between the pilot pump for supplying a signal pressure for moving the spring of the control valve and each of the control valves and detecting a pressure change in the pilot flow path; A flow path provided between the pilot pump and the back pressure side of the relief valve of the swing motor; A solenoid flow path opening and closing valve installed in the flow path to open / close the flow path according to a predetermined electrical signal; And a control unit for receiving the pressure signal value of the pressure switch and applying the predetermined electrical signal to the flow path opening and closing valve by a predetermined control operation. do.

The above-described plurality of actuators include a swing motor, a boom cylinder, and an arm cylinder, the swing motor and the arm cylinder are operated by the same pump, and the plurality of pressure switches described above operate the swing motor in the pilot flow path. Preferably, the pilot channel for obtaining, the pilot channel for obtaining the up operation of the boom cylinder, and the pilot channel for obtaining the out operation of the arm cylinder are preferably installed.

In addition, the above-described control unit, when the pressure change is detected in the pressure switch installed in the pilot flow path for obtaining the operation of the swing motor and at the same time the pressure change is detected in the pressure switch installed in the pilot flow path for obtaining the arm-out operation. A predetermined electrical signal is applied to the valve to open the aforementioned flow path.

Hereinafter, preferred embodiments of the present invention will be described based on the accompanying drawings.

2 shows a hydraulic circuit of a heavy equipment to which a relief pressure variable control device for a swing motor according to an embodiment of the present invention is applied.

As shown, the first and second hydraulic pumps P1 and P2 driven by the engine E / G and the pilot pumps P3 for supplying the signal pressure are provided, and the first and second hydraulic pressures are provided. A plurality of actuators 1, 3, 5 operated by the discharge flow rates of the pumps P1, P2 are provided. Of the plurality of actuators 1, 3, and 5 described above, reference numeral 1 denotes a swing motor, 3 denotes an arm cylinder, and 5 denotes a Boolean cylinder. Other actuators are not shown.

Between the first and second hydraulic pumps P1 and P2 and the actuators 1, 3 and 5, the discharge flow rates of the first and second hydraulic pumps P1 and P2 are transferred to the actuators 1, 3 and 5, respectively. The main control valve 7 is installed to selectively apply and control their operation and direction of operation. The main control valve 7 is a plurality of control valves (7a, 7b, 7c) and the control valves (7a, 7b, 7c) for controlling the operation and the direction of operation of the actuators (1, 3, 5) It consists of a flow path to connect. The switching connection of the internal flow paths of the control valves 7a, 7b, and 7c is made by the movement of the sprue in each of the control valves 7a, 7b, and 7c. By the signal pressure supply of the above-described pilot pump P3 through (15). An operation step for controlling the control valves 7a, 7b, and 7c by operating by the driver to flow or block the signal pressure of the pilot pump P3 to the pilot flow paths 11, 13, and 15 is omitted.

In the flow path between the control valve 7a of the swing motor 1 and the swing motor 1, two relief valves 21a and 21b for setting the operating pressure of the swing motor 1 are provided.

In the swing motor relief pressure variable control device of the present embodiment, the pressure switches 31, 33, 35 are provided as means for detecting the pressure change in the pilot flow paths 11, 13, and 15 described above. A flow path 37 connecting between the back pressure side of the valves 21a and 21b and the pilot pump P3 and a solenoid provided in the flow path 37 to open / close the flow path 37 by a predetermined electrical signal. The flow path opening and closing valve 39 is provided. In addition, the controller 41 is provided with the pressure signal detected by the pressure switches 31, 33, and 35 described above, and applies the predetermined electrical signal to the flow path opening / closing valve 39 described above. Increasing the pressure in the pilot flow paths 11, 13, and 15 means that the sprues of the corresponding control valves 7a, 7b, and 7c are moved, and the corresponding actuators 1, 3, and 5 are operating. This means that the sprues of the control valves 7a, 7b and 7c are in neutral and the corresponding actuators 1, 3 and 5 are not operating.

Preferably, as in this embodiment, the pilot flow path 11 is a pilot flow path that is applied to both the movement of the spring of the control valve 1 in both directions, and the input switch 31 installed in the pilot flow path 11 is the swing motor. Regardless of the direction of rotation of (1), it is configured to detect whether the swing motor 1 is operated unconditionally and apply an electrical signal corresponding to the control unit 41, while the pilot flow paths 13 and 15 are respectively controlled by a control valve ( The pilot flow paths applied only when the springs are moved in the one-way direction of the springs 3 and 5, and each of the input switches 33 and 35 installed in the pilot flow paths 13 and 15 has an out action of the arm cylinder 3 and the boolean cylinder 5, respectively. It is configured to detect only the up operation and apply an electrical signal corresponding thereto to the controller 41.

The controller 41 analyzes the applied electrical signal by a predetermined control operation, and then applies an electrical signal for driving the above-described flow path opening / closing valve 39 in some cases.

When the above-described electrical signal is applied to the flow path opening and closing valve 39 from the control unit 41, the flow path opening and closing valve 39 switches the flow path 37 to an open state, and the pilot pump ( As hydraulic pressure is supplied from P3 to the back pressure side of the two relief valves 21a and 21b, the set pressure of the relief valves 21a and 21b becomes high. On the other hand, when the electrical signal for driving the flow path opening and closing valve 39 from the control unit 41 is released, the flow path opening and closing valve 39 blocks the flow path 37 by the restoring force, thereby releasing from the pilot pump P3. The hydraulic force acting on the back pressure side of the relief valves 21a and 21b is released, and the set pressure of the relief valves 21a and 21b is lowered.

Next, an example of the control operation performed by the controller 41 described above will be described.

The pressure change (pressure increase) of the independent pilot flow paths 11, 13, and 15 is detected by the pressure switches 31, 33, and 35 so as to apply a corresponding electrical signal to the controller 41 (actuator 1, 3). (5) alone), the pressure change (pressure increase) at the same time of the two pilot flow paths (11, 15) is detected by the pressure switch (31, 35) to apply a corresponding electrical signal to the controller 41 (actuator (1,5 combined operation), the control unit 41 does not apply any electric signal to the above-described flow path opening and closing valve 39. That is, in this case, the flow path opening and closing valve 39 maintains the initial state of blocking the flow path 37. On the other hand, if the pressure change (pressure increase) at the same time of the two pilot flow paths 11 and 13 is detected by the pressure switches 31 and 33 and a corresponding electrical signal is applied to the controller 41 (the actuators 1 and 3), Combined operation), the control section 41 applies an electrical signal to the above-described flow path opening and closing valve 39. The flow path opening and closing valve 39 is switched to open the flow path 37, and as the hydraulic force of the pilot pump P3 is provided to the back pressure sides of the two relief valves 21a and 21b through the open flow path 37. The set pressure of the relief valves 21a and 21b becomes high.

The operation of this embodiment according to the type of work will be described below.

In the case of the loading operation in which the swing operation and the boom-up operation are combined, the pressure switch 11 and 15 detects a pressure change and applies an electrical signal to the control unit 41. However, the control unit 41 transmits an electric signal to the flow path opening and closing valve 39. Since no electrical signal is applied, the flow path 37 is cut off, and the set pressure of the relief valves 21a and 21b maintains a low pressure state. That is, it may have a buoyancy up effect during the loading operation, and thus the workability and safety are improved as the turning speed and the buoy-up speed are balanced in comparison with the related art.

In the case where the swing operation and the arm out operation are combined, for example, when the flattening operation is performed while turning, the pressure switch 11 and 13 detects a pressure change and applies an electrical signal to the control unit 41 and the control unit 41. ), The flow path 37 is opened by applying an electrical signal to the flow path open / close valve 39. Therefore, the set pressure of the relief valves 21a and 21b becomes high. Accordingly, as sufficient flow rate is supplied to the arm cylinder 3 side, responsiveness and workability in such an operation are remarkably improved.

As described above, according to the present invention, since the set pressure of the relief valve of the swing motor can be variably controlled to the optimum state according to the work type and the work requirements, the actuator responsiveness and operability at the time of combined operation This is promoted, and eventually improved workability and stability in the excavator can be obtained.

Claims (4)

At least one pump, a plurality of actuators including a swing motor actuated by the pumps, and a plurality of control valves for controlling the operation and the direction of operation of each of the actuators by a flow path switching connection by a spring movement. Applied to hydraulic equipment of heavy equipment; A plurality of pressure switches installed in a pilot pump between the pilot pump for supplying a signal pressure for moving the springs of the control valves and the respective pilot valves, and detecting a pressure change in the pilot channel; A flow path provided between the pilot pump and the back pressure side of the relief valve of the swing motor; A solenoid flow path opening and closing valve installed in the flow path to open / close the flow path according to a predetermined electrical signal; And a control unit which receives the pressure signal value of the pressure switch and applies the predetermined electrical signal to the flow path opening and closing valve by a predetermined control operation. The swing actuator of claim 1, wherein the plurality of actuators include a swing motor, a pour cylinder, and an arm cylinder, and the swing motor and the arm cylinder are operated by the same pump; The plurality of pressure switches are installed in each of the pilot flow passage, the pilot flow passage for obtaining the operation of the swing motor, the pilot flow passage for obtaining the boom cylinder operation and the pilot flow passage for obtaining the operation of the arm cylinder, respectively. Relief pressure variable control device for heavy duty swing motor. The swing actuator of claim 1, wherein the plurality of actuators include a swing motor, a pour cylinder, and an arm cylinder, and the swing motor and the arm cylinder are operated by the same pump; The plurality of pressure switches are respectively installed in the pilot flow passage, the pilot flow passage for obtaining the operation of the swing motor, the pilot flow passage for obtaining the up operation of the boom cylinder, and the pilot flow passage for obtaining the out operation of the arm cylinder, respectively. Relief pressure variable control device of the swing motor for heavy equipment, characterized in that. 4. The control unit according to claim 3, wherein the control unit detects a pressure change in a pressure switch installed in the pilot flow path for obtaining the operation of the swing motor, and at the same time, changes in pressure in the pressure switch installed in the pilot flow path for obtaining the arm out operation. Relief pressure variable control device for a swing motor for heavy equipment, characterized in that for opening the flow path by applying the predetermined electrical signal to the flow path opening and closing valve when detected.