Method for controlling cooling fan-brake of construction equipment

Abstract

The present disclosure provides a method for controlling a cooling fan-brake of construction equipment, including: generating a brake charging signal of a brake unit; charging hydraulic oil with a high flow rate in the brake unit and completing the charging of hydraulic oil; turning a loading valve of a cooling fan unit off and turning an unloading valve of the cooling fan unit on when the hydraulic oil is charged; and turning the loading valve of the cooling fan unit on and turning the unloading valve of the cooling fan unit off after the charging of hydraulic oil is completed and a predetermined time elapses.

Claims

1. A method for controlling a cooling fan-brake of construction equipment, comprising: generating a brake charging signal of a brake unit in a normally controlled state; wherein the normally controlled state includes a loading valve of a cooling fan unit in an on state and an unloading valve of the cooling fan unit in an off state; making, by a controller, when a brake priority valve and a brake charging valve of the brake unit operate so that a hydraulic oil with a high flow rate is charged in the brake unit, the loading valve of the cooling fan unit to turn off and the unloading valve of the cooling fan unit to turn on when charging of the hydraulic oil; and turning the loading valve of the cooling fan unit on and turning the unloading valve of the cooling fan unit off after the charging of hydraulic oil is completed and a predetermined time elapses.

2. The method of claim 1, wherein the brake charging valve of the brake unit is turned off when the hydraulic oil is completely charged.

3. The method of claim 1, wherein the predetermined time after the charging completion of the hydraulic oil is 0.5 second.

4. The method of claim 1, wherein the controller detects a pressure of the brake charging valve and determines whether the hydraulic oil is in a charged state based on the pressure.

5. The method of claim 4, wherein when the pressure of the brake charging valve detected is equal to or lower than 120 bar, the controller makes the hydraulic oil to be first charged in the brake charging valve.

6. The method of claim 4, wherein the controller makes the brake charging valve to continue to charge until the pressure of the hydraulic oil is equal to or greater than about 140 bar.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagram illustrating a cooling fan-brake control system of construction equipment.

(2) FIG. 2 is a graph illustrating overspeed of the cooling fan after a brake is charged in the cooling fan-brake control system of the construction equipment of FIG. 1.

(3) FIG. 3 is a circuit diagram illustrating a cooling fan-brake control system of construction equipment according to an exemplary embodiment of the present disclosure.

(4) FIG. 4 is a control flowchart illustrating a cooling fan-brake control method of construction equipment according to an exemplary embodiment of the present disclosure.

(5) FIG. 5 is a graph illustrating a change in speed of a cooling fan controlled by the cooling fan-brake control method of the construction equipment of FIG. 4.

DETAILED DESCRIPTION

(6) Hereinafter, a cooling fan-brake control method of construction equipment according to an exemplary embodiment of the present disclosure will be described in detail.

(7) As illustrated in FIGS. 1, and 3 to 5, in a cooling fan-brake control method of construction equipment according to an exemplary embodiment of the present disclosure, a controller 6 detects a pressure of a brake charging valve 4a of a brake unit 4 through a pressure detection unit 1 in a state where construction equipment starts (S100).

(8) In this case, a cooling fan 3 of the construction equipment is in a normally controlled state, and more preferably, hydraulic oil is charged from a brake priority valve 4b until the brake charging valve 4a of the brake unit 4 has a pressure of 120 bar or greater, and then hydraulic oil is loaded into a motor 3b of the cooling fan unit 3. Here, a loading valve 3c is in an on state, and an unloading valve 3d is in an off state so that the hydraulic oil is loaded into the motor 3b through the brake priority valve 4b.

(9) When the pressure of the brake charging valve 4a detected in operation S100 is equal to or lower than 120 bar (S110), the controller 6 makes the brake unit 4 to operate the brake priority valve 4b and the brake charging valve 4a so that the hydraulic oil is first charged in the braking charging valve 4a from the main control valve 7 (S120).

(10) Here, in the pump 5, a flow controller (not illustrated) is controlled so that a discharge rate of the hydraulic oil has a maximum value under the control of the controller 6, and the brake charging valve 4a may continue charging until the pressure of the hydraulic oil is equal to or greater than about 140 bar.

(11) In the meantime, in order to prevent the hydraulic oil with a high-pressure/high flow rate from being temporarily supplied to the motor 3b driving the cooling fan 3a of the cooling fan unit 3 through the brake priority valve 4b when the hydraulic oil is first charged to the brake charging valve 4a of the brake unit 4, the controller 6 makes the cooling fan unit 3 turn the unloading valve 3d on and turn the loading valve 3c off as illustrated in FIGS. 5B and 5C from a start time of the charging of the brake, so that loading of the hydraulic oil with a high flow rate loaded to the motor 3b is blocked (S130).

(12) After operations S120 and S130, the controller 6 subsequently detects whether the hydraulic oil is in a charged state by receiving a signal from a brake charging sensor 4c through the pressure detection unit 1, and then when the pressure of the braking charging valve 4a is equal to or greater than 140 bar (S140), the controller 6 makes the brake unit 4 operate the brake priority valve 4b and the brake charging valve 4a so that the brake charging valve 4a is prevented from being charged with the hydraulic oil from the main control valve 7 (S150).

(13) Here, in the pump 5, the flow controller (not illustrated) may be controlled so that a discharge rate of the hydraulic oil is in a normal state under the control of the controller 6.

(14) In the meantime, when the pressure of the brake charging valve 4a detected in operation S140 is equal to or greater than 140 bar, the controller 6 makes the cooling fan unit 3 to determine whether a predetermined time b, that is, 0.5 second, elapses from a time at which the charging of the brake is blocked (completed) (S160), and makes the cooling fan unit 3 to turn the unloading valve 3d off and turn the loading valve 3c on when the predetermined time b elapses as illustrated in FIGS. 5B and 5C, thereby allowing the normal amount of hydraulic oil to be loaded to the motor 3b (S170).

(15) Here, 0.5 second that is the predetermined time b represents a minimum time for which the discharged hydraulic oil at a moment of completion of the charging of the brake is drained to a tank so as to have the same flow rate as that of the discharged hydraulic oil before generating charging of the brake. That is, the hydraulic oil is prevented from being loaded to the motor 3b for about 0.5 second after the start and the completion of the charging of the brake, so that even though the charging of the brake is completed, it is possible to prevent overspeed of the motor 3b generated by the hydraulic oil with a high flow rate existing in a hydraulic oil supply line.

(16) Accordingly, the cooling fan-brake control method of the construction equipment, as illustrated in FIG. 5D, revolutions per minute of the cooling fan 3a are decreased from the start time of the charging of the brake to the charging completion time (a) and the predetermined time (b) after the charging completion time (a), thereby preventing overspeed of the cooling fan 3a.

(17) Although the exemplary embodiments of the present disclosure have been described with reference to accompanying drawings, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope of the technical spirit or the essential feature of the disclosure, so that the exemplary embodiments may be implemented to other particular forms. Therefore, it shall be understood that the aforementioned exemplary embodiments are all illustrative and are not restrictive.

(18) According to the cooling fan-brake control method of construction equipment according to the present disclosure, when a charging signal of the brake is generated from the brake unit, hydraulic oil of a high flow rate, which is loaded to the cooling fan unit, is unloaded from a start time of charging of the brake to a completion time of the charging of the brake and a predetermined time, so that revolutions per minute of the cooling fan are decreased for a section of the unloading, thereby preventing overspeed of the cooling fan, which exceeds the limit of the existing technology, and in this respect, there is a possibility in that the relevant technology is used, a device, to which the present disclosure is applied, sufficiently comes into the market or is on sale, and the present disclosure may be clearly realistically implemented, so that the present disclosure is an industrially applicable disclosure.