KR20110064420A - Hydraulic circuit for construction machinery - Google Patents

Abstract

PURPOSE: A hydraulic circuit of construction machinery is provided to prevent the meandering of construction machinery by controlling the flow rate of working fluid supplied to first and second traveling motors uniformly when making a straight drive, thereby operating first and second travel motors at the same speed of revolution. CONSTITUTION: A hydraulic circuit of construction machinery comprises: a pair of first hydraulic lines(41,42) connecting a first travel control valve(21) and a first travel motor(31); a pair of second hydraulic lines(51,52) connecting a second travel control valve(22) and a second travel motor(32); and a first flow rate control valve(61) installed between a pair of the first hydraulic lines to make a pair of the first hydraulic lines communicate with each other, and controlling the flow rate of working fluids flowing between a pair of the first hydraulic lines to control the flow rate of working fluids supplied to the first travel motor.

Description

HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINERY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to construction machinery such as excavators, and more particularly to a hydraulic circuit of construction machinery having a traveling motor that is rotationally driven by hydraulic fluid.

Referring to FIG. 1, a general construction machine travels through a pair of traveling motors consisting of a left driving motor 1 and a space running motor 2. The operating oil whose flow direction is controlled by the left traveling control valve 3 is supplied to the left traveling motor 1, and the operating oil whose flow direction is controlled by the space traveling control valve 4 is supplied to the space traveling motor 2. Supplied. At this time, the rotational speed of the left running motor 1 and the space running motor 2 varies depending on the flow rate of the hydraulic oil supplied. Therefore, in order for the construction machine to go straight by the traveling straight signal, the same flow rate must be supplied to the left driving motor 1 and the space running motor 2.

However, due to the processing error and assembly error of each running spool or the processing error of each flow path, despite the need to go straight, the actual construction machine is a meandering phenomenon that is running inclined to one side.

This meandering phenomenon not only makes traveling control of construction machinery difficult, but also causes a big accident in narrow roads and slopes.

The present invention has been made in view of the above-described point, and an object thereof is to provide a hydraulic circuit of a construction machine that can prevent meandering of the construction machine when driving straight.

Hydraulic circuit of the construction machine according to the present invention for achieving the object as described above is the first and second travel control valve 21, 22 for controlling the flow direction of the hydraulic oil discharged from the hydraulic pump 10, Applied to a construction machine including a first and a second travel motor 31, 32 which is driven and driven by the operating oil controlled in the flow direction by each of the first and second travel control valve (21) (22) A pair of first hydraulic lines (41) (42) connecting the first travel control valve (21) to the first travel motor (31); A pair of second hydraulic lines (51) (52) connecting said second travel control valve (22) and said second travel motor (32); And between the pair of first hydraulic lines 41 and 42 so that the pair of first hydraulic lines 41 and 42 communicate with each other, the pair of first hydraulic lines 41 and 42 ( And a first flow control valve (61) (161) for controlling the flow rate of the working oil supplied to the first driving motor (31) by adjusting the flow rate of the working oil flowing between the 42.

According to an embodiment of the present invention, the hydraulic circuit of the construction machine is between the pair of second hydraulic lines 51, 52 so that the pair of second hydraulic lines 51, 52 communicate. A second flow control valve 62 (162) for controlling a flow rate supplied to the second travel motor 32 by adjusting a flow rate flowing between the pair of second hydraulic lines 51 and 52; It may further include.

According to another embodiment of the present invention, the hydraulic circuit further includes an adjusting unit 170 for outputting an electrical signal for adjusting the opening amount of the first flow control valve 161.

According to the problem solving means as described above, the flow rate of the hydraulic oil supplied to the first traveling motor by the first flow control valve can be adjusted, so that the flow rate of the hydraulic oil supplied to the first and second traveling motor at the same time as driving straight It can be adjusted so that it is possible to drive the first and second traveling motor at the same rotational speed to prevent meandering of the construction machine.

As such, by preventing the meandering of the construction machine, it is possible to easily control the running of the construction machine, as well as to prevent the safety accident that may occur in narrow lengths or slopes at the source.

Meanwhile, by adjusting the flow rate of the hydraulic oil supplied to the second travel motor by the second flow control valve together with the flow rate of the hydraulic oil supplied to the first travel motor, the flow rate of the hydraulic oil supplied to the first and second travel motors is adjusted. It can be precisely adjusted, and can effectively prevent meandering when the construction machine moves forward and backwards.

In addition, by providing a control unit for adjusting the opening amount of the first and second flow control valve, it is possible to easily correct the meandering phenomenon of the construction machine in the driver's seat.

Hereinafter, the hydraulic circuit of the construction machine according to an embodiment of the present invention will be described in detail.

2, the hydraulic circuit of the construction machine according to an embodiment of the present invention and the first and second travel control valve 21 and 22 for controlling the flow direction of the hydraulic oil discharged from the hydraulic pump 10 and And a first and second travel motors 31 and 32 that are supplied with hydraulic oil whose flow direction is controlled by the first and second travel control valves 21 and 22, respectively, and is driven to rotate. As applied, a pair of first hydraulic lines 41 and 42 connecting the first travel control valve 21 and the first travel motor 31, the second travel control valve 22 and And a pair of second hydraulic lines 51 and 52 connecting the second travel motor 32 and first and second flow control valves 61 and 62.

The hydraulic oil discharged from the hydraulic pump 10 is controlled by the first and second travel control valves 21 and 22 to control the flow direction of the first and second travel motors 31 and 32. Supplied to each. The first and second travel control valves 21 and 22 are converted according to a signal input from a travel operation unit such as a travel lever or a travel pedal to control the flow direction of the hydraulic oil discharged from the hydraulic pump 10. Therefore, the flow direction and the flow rate of the hydraulic oil supplied to the first and second travel motors 31 and 32 are controlled according to the operation signal generated by the travel operation unit.

When a driving straight signal is input through the driving operation unit, the first and second driving control valves 21 and 22 are converted in the same manner to each of the first and second driving motors 31 and 32. It is designed to supply the same flow rate. However, even if a driving straight signal is generated from the travel operation unit due to various reasons such as processing errors and assembly errors of the first and second travel control valves 21 and 22 or processing errors and assembly errors of the travel operation unit, Flow rates supplied to the first and second driving motors 31 and 32 are different from each other, and thus, a meandering phenomenon occurs in which the construction machine is driven to one side without traveling straight.

In order to prevent such a meandering phenomenon, the flow rates supplied to the first and second traveling motors 31 and 32 should be equally adjusted. Such a function may be performed by the first and second flow control valves 61 and 62. Is implemented by Details of the first and second flow control valves 61 and 62 will be described later.

The pair of first hydraulic lines 41 and 42 are connected to the first hydraulic line 41 connected to one side of the first driving motor 31 and the other side of the first driving motor 31. And a second hydraulic line 42. When the first travel control valve 21 is converted to one side, hydraulic oil is supplied to the first travel motor 31 through the 1-1 hydraulic line 41 so that the first travel motor 31 is in one direction. And the hydraulic fluid driving the first travel motor 31 are drained to the tank through the 1-2 hydraulic line 42 and the first travel control valve 21. On the other hand, when the first travel control valve 21 is converted to the other side, the hydraulic oil is supplied to the first travel motor 31 through the 1-2 hydraulic line 42, the first travel motor 31 Is rotationally driven in the other direction, and the hydraulic oil driving the first travel motor 31 is drained to the tank through the first-first hydraulic line 41 and the first travel control valve 21.

The pair of second hydraulic lines 51 and 52 are connected to the second hydraulic line 51 connected to one side of the second driving motor 32 and the other side of the second driving motor 32. And a second hydraulic line 52. Since the 2-1 hydraulic line 51 and the 2-2 hydraulic line 52 have the same function as the 1-1 and 1-2 hydraulic lines 41 and 42, detailed description thereof will be omitted.

The first flow control valve 61 communicates between the first-first hydraulic line 41 and the first-second hydraulic line 42 so that the first-first and 1-2 hydraulic lines 41 are in communication with each other. The hydraulic fluid of the supply line for supplying the hydraulic fluid to the first travel motor 31 is discharged to the drain line. Accordingly, the flow rate at which the operating oil of the supply line is discharged to the drain line is varied according to the opening amount of the first flow control valve 61, thereby adjusting the flow rate supplied to the first travel motor 31 through the supply line. It becomes possible.

For example, the first travel control valve 21 is converted to one side so that hydraulic oil is supplied to the first travel motor 31 through the 1-1 hydraulic line 41 and the 1-2 hydraulic line 42. If it is drained through, a part of the flow rate of the hydraulic oil supplied to the first driving motor 31 through the 1-1 hydraulic line 41 is the first through the first flow control valve 61 1-2 Drained to the hydraulic line 42 and drained to the tank. As such, the first flow control valve 61 adjusts the flow rate of the hydraulic oil supplied to the first travel motor 31, and thus the flow rate adjusted in this way is used to supply the hydraulic fluid supplied to the second travel motor 32. When the flow rate is the same, the first and second travel motors 31 and 32 are driven at the same rotational speed, whereby the construction machine can travel straight.

Accordingly, in the present embodiment, two first and second flow control valves 61 and 62 are used. However, unlike the present embodiment, one of the first and second flow control valves 61 and 62 is different. Using only one can achieve the object of the present invention. When only one flow control valve is used, the flow rate of the hydraulic oil supplied to the traveling motor using the flow control valve is measured by measuring the flow rate or the pressure of the hydraulic oil supplied to the traveling motor without the flow control valve. It is possible to adjust the flow rate of the working oil supplied to the same.

The second flow control valve 62 is for controlling the flow rate of the hydraulic oil supplied to the second travel motor 32, and only has a different function of the flow rate adjustment, so that the second flow control valve 62 functions the same as the first flow control valve 61. , Detailed description is omitted.

In this way, by using the two flow control valves 61 and 62, the first and second traveling motors 31 and 32 are rotated in one direction (when going straight) as well as rotating in the other direction. Even in the case of driving (backward), the flow rate supplied to the first and second traveling motors 31 and 32 can be adjusted in the same manner, thereby preventing the meandering of construction machinery.

3 is a view schematically showing a hydraulic circuit of a construction machine according to another embodiment of the present invention.

Referring to FIG. 3, according to another embodiment of the present invention, the first and second flow control valves 161 and 162 include an electronic valve whose opening amount is adjusted by an electric signal. The control unit 170 for transmitting an electric signal to the two flow control valves (161, 162) is provided in the driver's seat. The adjusting unit 170 may include a first adjusting unit 171 for adjusting the opening amount of the first flow control valve 161 and a second opening for adjusting the opening amount of the second flow control valve 162. And an adjusting unit 172.

By such a configuration, when the driver travels a construction machine and a meandering phenomenon occurs, the first and second flow control valves 161 are provided through the first and second adjusting units 171 and 172 provided in the driver's seat. By adjusting the opening amount of 162, it is possible to easily correct the meandering phenomenon of construction machinery.

1 is a hydraulic circuit diagram schematically showing a hydraulic circuit of a conventional construction machine,

2 is a hydraulic circuit diagram schematically showing a hydraulic circuit of a construction machine according to an embodiment of the present invention;

3 is a hydraulic circuit diagram schematically showing a hydraulic circuit of a construction machine according to another embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS

10; Hydraulic pumps 21 and 22; First and second travel control valve

31, 32; First and second travel motors 41 and 42; 1st hydraulic line

51, 52; Second hydraulic lines 61 and 161; 1st flow control valve

62, 162; A second flow control valve 170; Control

171, 172; 1st and 2nd control part

Claims (3)

The first and second travel control valves 21 and 22 for controlling the flow direction of the hydraulic oil discharged from the hydraulic pump 10 and the first and second travel control valves 21 and 22 respectively flow. In the hydraulic circuit of a construction machine comprising the first and second travel motors 31 and 32 driven and supplied with hydraulic oil controlled in a direction, A pair of first hydraulic lines (41) (42) connecting the first travel control valve (21) and the first travel motor (31); A pair of second hydraulic lines (51) (52) connecting said second travel control valve (22) and said second travel motor (32); And It is installed between the pair of first hydraulic lines 41 and 42 so that the pair of first hydraulic lines 41 and 42 communicate with each other, and the pair of first hydraulic lines 41 and 42 communicate with each other. Hydraulic circuit of the construction machine, characterized in that it comprises a first flow control valve (61, 161) for controlling the flow rate of the operating oil supplied to the first driving motor 31 by adjusting the flow rate of the operating oil flowing between) . The method of claim 1, Installed between the pair of second hydraulic lines 51 and 52 such that the pair of second hydraulic lines 51 and 52 communicate with each other, the pair of second hydraulic lines 51 and 52 communicate with each other. And a second flow rate control valve (62) (162) for adjusting the flow rate supplied to the second travel motor (32) by adjusting the flow rate between the two. The method of claim 1, Hydraulic circuit of a construction machine, characterized in that it further comprises an adjustment unit 170 for outputting an electrical signal for adjusting the opening amount of the first flow control valve (161).

Images