KR101518056B1 - Boom position control system for construction machinery - Google Patents

Abstract

A boom position control system for a construction machine according to the present invention comprises a frame (10), a frame (10) provided rotatably in the up and down direction and connected to the frame (10) in accordance with an operation signal of the boom operation lever A first electromagnet (21) applied to a construction machine including a boom (11) rotating in a vertical direction, the boom operation lever (12) being maintained in a raised position; A second electromagnet 22 for maintaining the state in which the boom operation lever 12 is operated to the lowered position; The boom 11 is provided at one of the frame 10 and the boom 11 and has a first position for stopping the raising of the boom 11 and a second position for stopping the raising and lowering of the boom 11 First and second recognition units (31) and (32) for displaying each of them; One position detection sensor (40) provided on any one of the frame (10) and the boom (11) and sensing the first and second recognition units (31, 32); And the boom operation lever (12) is returned from a raised position or a lowered position to a neutral position when the position detection sensor (40) senses any one of the first and second recognition units (31, 32) And a control unit 50 for outputting control signals to the first and second electromagnets 21 and 22 to stop the raising and lowering operation of the boom 11.

Boom, automatic elevating and lowering, position detecting sensor, one, first and second recognizing parts, reduced number of parts

Description

[0001] BOOM POSITION CONTROL SYSTEM FOR CONSTRUCTION MACHINERY [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction machine such as a wheel loader or an excavator, and more particularly to a boom position control system of a construction machine for automatically controlling the lifting drive of a boom.

Construction machines, such as wheel loaders, are often used for transporting or transporting soil. More specifically, the wheel loader transports the gravel to a position close to a transportation means such as a truck, and then raises the bucket to dump the gravel to the transportation means. After the bucket is lowered again, the wheel loader moves to a place where the gravel is accumulated, . This work is repeated many times until the soil is filled in the vehicle. Therefore, the wheel loader driver must repeatedly perform the operation of raising and lowering the bucket to the vehicle.

In recent years, a boom position control system has been developed to automatically raise and lower the bucket so that the work repeatedly performed can be more easily performed. In the boom position control system, when the boom is raised to a certain position, the boom is stopped from being raised. On the other hand, when the boom is lowered to a predetermined position, the boom is stopped from being lowered. An example of such a boom position control system is shown in Fig.

Referring to Fig. 1, one end of a pair of booms 2 is mounted on a frame 1 so as to be rotatable. One of the pair of booms (2) is provided with a first recognition plate (3) for detecting the position of the rising limit of the boom (2), and one of the pair of booms (2) A second recognition plate 4 is provided for sensing a lowering limit position of the second recognition plate 2. In addition, the frame 1 is provided with first and second proximity sensors 5 and 6 for sensing the first and second recognition plates 3 and 4.

In such a boom position control system, when the boom operation lever is operated to the raised position, the boom operation lever is held at the raised position by the one-side electromagnet. Therefore, even if the operator does not pull the boom operation lever, the boom 2 continues to rise. At this time, when the first proximity sensor 5 senses the first recognition plate 3, the current supplied to the one electromagnet is cut off and the boom operation lever is returned to the neutral position, ) Stops the rising drive. On the contrary, when the operator operates the boom operation lever to the lowered position, the state operated by the other electromagnet is maintained, and the boom 2 continues to descend. When the boom (1) is positioned at a position for sensing the second recognition plate (4) by the second proximity sensor (6), the current supplied to the second electromagnet is cut off and the boom operation lever And the downward movement of the boom 2 is stopped.

However, since the convenient boom position control system as described above must necessarily use a pair of proximity sensors 5 and 6, there is a limit in reducing the number of parts, and a pair of proximity sensors 5 and 6, A circuit for transmitting a signal output from the electromagnet to a pair of electromagnets is complicated, which limits the system to a simple one.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a boom position control system for a construction machine which can simplify a system and reduce a cost by reducing the number of parts.

The boom position control system includes a frame (10), a frame (10) rotatably mounted on the frame (10), and a boom operation lever (12) And a boom (11) rotating in a vertical direction with respect to the frame (10) in accordance with an operation signal generated by operating the boom operation lever (12) from an up position or a down position, characterized in that the boom operation lever A position holding unit (21) (22) for selectively holding the operated state to the up position or the down position; The boom 11 is provided at one of the frame 10 and the boom 11 and the first position of the boom 11 for stopping the raising and lowering of the boom 11 is stopped First and second recognition units 31 and 32 for respectively indicating a second position of the boom 11 for making the boom 11; One position detection sensor (40) provided on any one of the frame (10) and the boom (11) and sensing the first and second recognition units (31, 32); And the boom operation lever (12) is returned from a raised position or a lowered position to a neutral position when the position detection sensor (40) senses any one of the first and second recognition units (31, 32) And a control unit 50 for outputting a control signal to the position maintaining units 21 and 22 to stop the raising and lowering operation of the boom 11.

According to an embodiment of the present invention, the position holding units 21 and 22 include a first electromagnet 21 for selectively holding a state in which the boom operation lever 12 is operated to the raised position; And a second electromagnet (22) for selectively holding the state in which the boom operation lever (12) is operated to the lowered position.

If the position sensing sensor 40 does not sense the first recognition unit 31, the controller 50 is switched to supply current to the first electromagnet 21, A first switch (51) which is switched to cut off a current supplied to the first electromagnet (21) when the first recognition unit (31) is sensed; And the position sensing sensor 40 is adapted to supply current to the second electromagnet 22 when the position sensing sensor 40 does not sense the second recognition portion 32, And a second switch (52) that is switched to shut off the current supplied to the second electromagnet (22) when it senses the second electromagnet (32).

The position sensing sensor 40 is installed in the frame 10 and the first and second recognition units 31 and 32 are installed in the boom 11 to be adjustable in position.

According to a preferred embodiment of the present invention, the first and second recognition units are configured to be sensed by a single position sensor, and the up and down movement of the boom is controlled by a control signal output by the one position sensor. So that the number of components can be reduced, thereby reducing the cost of the construction machine.

In addition, the circuit for controlling the first and second electromagnets can be simplified by a signal output from the one position sensor, thereby simplifying the system and further reducing the cost of the construction machine .

Particularly, by using the first and second switches as the control unit, a more simplified system can be realized.

Hereinafter, a boom position control system for a construction machine according to an embodiment of the present invention will be described in detail.

2 to 3B, a boom position control system for a construction machine according to an embodiment of the present invention includes a frame 10, a frame 10 mounted on the frame 10 so as to be rotatable up and down, And a boom 11 that rotates in the vertical direction with respect to the frame 10 in accordance with an operation signal generated by operating the boom 11 from a neutral position to a raised position or a lowered position. The boom position control system includes the position maintaining units 21 and 22, the first and second recognizing units 31 and 32, the position sensing sensor 40 and the control unit 50.

The boom 11 is driven by a boom cylinder (not shown). The boom cylinder is supplied with operating oil that has passed through a boom control valve, and the boom control valve is converted according to an applied signal to supply operating oil discharged from the main pump to the boom cylinder. Whereby the boom cylinder is elongated and contracted. On the other hand, a signal for converting the boom control valve is generated by the boom operation lever 12. [ When the boom operation lever 12 is in the neutral position, the boom operation lever 12 does not output any signal to the boom control valve. Therefore, the operating oil is not supplied to the boom cylinder, and thereby the boom 11 is stopped. On the other hand, when the boom operation lever 12 is operated to the raised position, the boom control valve is changed so that the boom cylinder is extended so that the boom 11 is driven upward. On the contrary, when the boom operation lever 12 is operated to the lowered position, the boom control valve is switched so that the boom cylinder is contracted, and thereby the boom 11 is driven to descend.

The position holding units 21 and 22 are for holding the boom operation lever 12 in an operated state in a raised or lowered position and include first and second electromagnets 21 and 22. More specifically, the boom operation lever 12 is provided with a magnetic body, so that the boom operation lever 12 can be moved upward or downward in a state where current is supplied to the first and second electromagnets 21 and 22 The boom operation lever 12 is attached to the first electromagnet 21 or the second electromagnet 22 at the operated position and fixed to the operated position.

More specifically, the first electromagnet 21 is for maintaining the state where the boom operation lever 12 is operated to the raised position, and when the boom operation lever 12 is in the neutral position, The magnetic body of the first electromagnet 21 is not attached by the magnetic force of the first electromagnet 21. However, when the boom operation lever 12 is operated to the raised position, the magnetic body of the boom operation lever 12 is attached to the first electromagnet 21 by the magnetic force of the first electromagnet 21. Therefore, when a current is supplied to the first electromagnet 21 and the boom operation lever 12 is operated to the raised position, the boom operation lever 12 is kept operated in the raised position. In this state, when the current supplied to the first electromagnet 21 is cut off, the boom operation lever 12 moves away from the first electromagnet 21 and returns to the neutral position.

The second electromagnet 22 is for holding the boom operation lever 12 in the operated state in the lowered position and is configured to move the boom operation lever 12 to the lowered position Is maintained. Therefore, detailed description of the action of the second electromagnet 22 will be omitted.

The first and second recognition units 31 and 32 are installed at a specific position of the boom 11 so as to allow the position detection sensor 40 to selectively sense the boom 11 as it ascends and descends. will be. More specifically, the first recognizing unit 31 is for displaying a first position for restricting the elevation position of the boom 11, and the second recognizing unit 32 is for detecting a descending position of the boom 11 And to indicate the second position for limiting. The first and second recognition units 31 and 32 are installed in the boom 11. Hereinafter, a structure in which the first and second recognition units 31 and 32 are installed on the boom 11 will be described.

The first and second recognition units 31 and 32 are installed in a bracket 33 provided on the boom 11. The bracket 33 is formed with an arc-shaped slot 34 around the rotation axis AB of the boom 11. The first recognition unit 31 is installed on the lower side of the long hole 34 with bolts 35 and the second recognition unit 32 is installed on the upper side of the long hole 34 with bolts 35. [ do. When the bolt 35 is released, the first and second recognition units 31 and 32 can change their positions. Accordingly, the operator can adjust the positions of the first and second recognition units 31 and 32 according to the height of the transportation means. Here, the positions of the first and second recognition units 31 and 32 are the positions where the driving of the boom 11 is stopped as described above.

The position sensing sensor 40 senses the first and second recognition units 31 and 32 and outputs the sensed result to the control unit 50. In this embodiment, Various sensors may be used as long as they can detect the first and second recognition units 31 and 32 such as an optical sensor. The position sensing sensor 40 is installed in the frame 10 so as to face the first and second recognition units 31 and 32. The position sensing sensor 40 may be installed on the boom 11 and the first and second recognition units 31 and 32 may be installed on the boom 11, unlike the present embodiment.

The control unit 50 outputs control signals to the first and second electromagnets 21 and 22 based on the information about the position of the boom 11 transmitted from the position sensor 40. More specifically, when the position sensing sensor 40 does not sense the first and second recognition units 31 and 32, the control unit 50 controls the first and second electromagnets 21 and 22 So that the boom operation lever 12 is maintained in the raised or lowered position and the position detection sensor 40 detects the position of any one of the first and second recognition units 31 and 32 The electric current supplied to the first and second electromagnets 21 and 22 is cut off to return the boom operation lever 12 from the raised position or the lowered position to the neutral position. As a result, the raising or lowering drive of the boom 11 is stopped.

The controller 50 includes a first switch 51 for selectively interrupting a current supplied to the first electromagnet 21 according to a signal from the position sensor 40, And a second switch (52) for selectively interrupting the current supplied to the second electromagnet (22). Although the first and second switches 51 and 52 are configured as a relay switch in the present embodiment, various switches may be used, and a microprocessor or the like may be used as the control unit 50 It is possible.

Hereinafter, the operation of the boom position control system having the above-described configuration will be described.

3A shows a state in which current is supplied to the first and second electromagnets 21 and 22. When the boom operation lever 12 is operated to the raised position or the lowered position in the state as shown in Fig. The lever 12 is attached to any one of the first and second electromagnets 21 and 22 to maintain the operated state. Therefore, the boom 11 continuously ascends or descends continuously. In this state, when the position sensing sensor 40 senses any one of the first and second recognition units 31 and 32, the state shown in FIG. 3B is obtained.

3B, the '0' terminal of the position sensing sensor 40 is not grounded in the state of FIG. 3A, and the position sensing sensor 40 is connected to the first and second recognition units 31 32 is detected. When the '0' terminal of the position detection sensor 40 is grounded, a current flows to the relay 51a of the first switch 51, whereby the first switch 51 is connected to the '+' terminal and the first electromagnet 21 to be electrically isolated from each other. Therefore, the electric current supplied to the first electromagnet 21 is cut off. When the '0' terminal of the position sensor 40 is grounded, a current also flows to the relay 51b of the second switch 52, whereby the second switch 52 is connected to the '+' So that the electromagnets 22 are electrically disconnected from each other. As a result, the electric current supplied to the second electromagnet 22 is cut off.

The current flowing through the first and second electromagnets 21 and 22 is cut off so that the boom operation lever 12 is returned to the neutral position away from the first and second electromagnets 21 and 22, The elevation drive of the boom 11 is stopped.

In this way, the first and second recognition units 31 and 32 can be detected by the single position detection sensor 40, thereby stopping the upward movement and the downward movement of the boom 11, In addition, the system can be simplified.

1 is a perspective view schematically showing a mounting structure of a sensor for a general boom position control system,

FIG. 2 is a perspective view schematically illustrating a structure for mounting a position sensor of a boom position control system according to an embodiment of the present invention;

FIG. 3A and FIG. 3B are circuit diagrams schematically showing a boom position control system according to an embodiment of the present invention, and are views for explaining the operation of the boom position control system.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS

10; Frame 11; Boom

12; Boom operation levers 21, 22; The first and second electromagnets

31, 32; First and second recognition units 40; Position sensor

50; A control unit 51; The first switch

52; The second switch

Claims (4)

A frame 10 which is connected to the frame 10 and which is rotatably mounted in a vertical direction and is rotatably supported by the frame 10 in accordance with an operation signal generated by operating the boom operation lever 12 from a neutral position to a raised position or a lowered position, 10. A boom position control system for a construction machine, comprising a boom (11) rotating in a vertical direction with respect to a boom (10) A position holding unit (21) (22) for selectively holding the state in which the boom operation lever (12) is operated to the up position or the down position; The boom 11 is provided at one of the frame 10 and the boom 11 and the first position of the boom 11 for stopping the raising and lowering of the boom 11 is stopped First and second recognition units 31 and 32 for recognizing a second position of the boom 11, respectively; One position detection sensor (40) provided on any one of the frame (10) and the boom (11) and sensing the first and second recognition units (31, 32); And When the position detection sensor 40 senses any one of the first and second recognition units 31 and 32, the boom operation lever 12 is returned to the neutral position from the raised position or the lowered position, And a control unit (50) for outputting a control signal to the holding units (21) and (22) to stop the elevation driving of the boom (11) The position-maintaining units 21 and 22, A first electromagnet (21) for selectively holding the state in which the boom operation lever (12) is operated to the raised position; And And a second electromagnet (22) for selectively retaining the state in which the boom operation lever (12) is operated to the lowered position, The control unit (50) If the position sensing sensor 40 does not sense the first recognition unit 31, one of the terminals formed in the position sensing sensor 40 is not grounded and the first electromagnet 21 And when the position sensing sensor 40 senses the first recognition portion 31, one terminal of the position sensing sensor 40 is grounded and supplied to the first electromagnet 21 A first switch (51) which is switched to shut off the current; And If the position detecting sensor 40 does not detect the second recognizing part 32, one terminal of the position detecting sensor 40 is not grounded and supplies a current to the second electromagnet 22 And when the position sensing sensor 40 senses the second recognition unit 32, one terminal of the position sensing sensor 40 is grounded to cut off the current supplied to the second electromagnet 22 And a second switch (52) that is switched to the second switch (52). delete delete The method according to claim 1, The position sensor 40 is installed in the frame 10, Wherein the first and second recognition units (31, 32) are positionally adjustable to the boom (11).

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