WO2013051740A1

WO2013051740A1 - Control system for operating work device for construction machine

Info

Publication number: WO2013051740A1
Application number: PCT/KR2011/007439
Authority: WO
Inventors: 정해균; 송영복
Original assignee: 볼보 컨스트럭션 이큅먼트 에이비
Priority date: 2011-10-07
Filing date: 2011-10-07
Publication date: 2013-04-11
Also published as: JP5802338B2; EP2772653A1; EP2772653A4; CN103842663A; JP2014534386A; US20140238010A1; KR20140074306A

Abstract

Disclosed is a control system for controlling flow so as to allow simultaneous usage of a parallel flow path and a tandem flow path thereby reducing loss of pressure inside a control valve, when simultaneously operating work devices having different operating pressures. A control system for operating the work device, according to the present invention, provides the control system for operating the work device for a construction machine, comprising: first and second hydraulic pumps that are connected to an engine; a revolution control valve, an arm control valve, and a left driving control valve, which are installed on a first center bypass path of the first hydraulic pump, and each of which is connected via the parallel flow path; a boom control valve, a bucket control valve, and a right driving valve, which are installed on a second center bypass path of the second hydraulic pump, and each of which is connected via the parallel flow path; a pressure generation device; a bleed flow path, which is formed on a control spool at a lower side of a boom of the boom control valve, for maintaining an open state of the second center bypass path without closing same, when the boom control valve is switched so as to lower the boom; and a center bypass switch valve, which is installed on the lowermost side of the second center bypass path and is switched by means of a control signal for switching the boom control valve.

Description

Working device drive control system for construction machinery

The present invention relates to a work machine drive control system for a construction machine, and more particularly, when operating a work device having a different operating pressure at the same time (for example, to drive a work device such as a boom down operation of an excavator and a bucket, etc. simultaneously. The present invention relates to a drive system control system for a construction machine that reduces pressure loss inside a control valve by controlling a flow rate so that a parallel passage and a tandem passage can be used at the same time.

The construction machine boom drive control system according to the prior art shown in Figure 1,

The engine 1,

A variable displacement first and second hydraulic pumps 2 and 3 (hereinafter referred to as "first and second hydraulic pumps") and a pilot pump 4 connected to the engine 1,

A swing control valve (7) installed in the first center bypass passage (5) of the first hydraulic pump (2) and connected to a parallel channel (5a), respectively, to control the driving of the swing motor (6); An arm control valve 9 for controlling the drive of the arm cylinder 8, a travel control valve 11 for controlling the drive of the left traveling motor 10,

A boom control valve 14 and a bucket cylinder, which are installed in the second center bypass passage 12 of the second hydraulic pump 3 and connected to the parallel passage 12a, respectively, and control the driving of the boom cylinder 13; 15) a bucket control valve 16 for controlling the drive, a travel control valve 18 for controlling the drive of the right traveling motor 17,

And

pressure generators

19 and 20 for outputting a control signal corresponding to the manipulated variable.

When the above-described pressure generating device 19 is placed in the neutral position, the hydraulic oil discharged from the second hydraulic pump 3 passes through the second center bypass passage 12 and the return passage 21 to provide a hydraulic tank ( Return to T).

When operating the pressure generator 19 to raise the boom, the pilot signal pressure from the pilot pump 4 is supplied to the boom control valve 14 via the pressure generator 19. As a result, since the boom control valve 14 is switched to the boom up position (switched to the left in the drawing), the hydraulic oil discharged from the second hydraulic pump 3 is loaded with the load check valve 22 and the boom control valve 14. It is supplied to the large chamber of the boom cylinder 13 via). At the same time, the hydraulic oil flowing out of the small chamber of the boom cylinder 13 is returned to the hydraulic tank T via the boom control valve 14. Therefore, the boom cylinder 13 is extended and driven so that the boom can be raised.

On the other hand, when operating the pressure generator 19 in the boom down position to lower the boom, the pilot signal pressure from the pilot pump 4 is shown through the pressure generator 19 to the boom control valve 14. Switch to up or right direction. Therefore, the hydraulic oil discharged from the second hydraulic pump 3 is supplied to the small chamber of the boom cylinder 13 via the boom control valve 14. At the same time, the hydraulic oil flowing out of the large chamber of the boom cylinder 13 is returned to the hydraulic tank T via the boom control valve 14 and the back pressure check valve 23. Therefore, the boom cylinder 13 is contracted and driven so that the boom can be lowered.

At this time, when the flow rate passes as the valve spring is mounted on the above-described back pressure check valve 23, a constant pressure is formed. In addition, as the regeneration line is installed in the boom control valve 14, the flow rate flowing out of the large chamber of the boom cylinder 13 when the boom is down may be regenerated into a small chamber.

As described above, when the boom is down, the boom is down by its own weight, thereby causing a low pressure. On the other hand, when operating a boom down operation and a work device requiring a relatively high pressure (for example, a bucket) at the same time, the boom lower side control spool (boom control valve 14) to maintain simultaneous operation of the boom and the bucket By installing the throttling device on the flow inlet side of the flow rate can be maintained at the same time.

On the other hand, in preparation for the pressure to raise the boom, by installing the throttling device in the parallel flow path of each work device operating at a relatively low pressure, it is possible to realize the simultaneous operation of the boom raising and other work devices.

In addition, a tandem passage is formed in the bucket control valve 16 and the traveling control valve 18 connected in parallel with the above-described boom control valve 14 through the second center bypass passage 12. That is, when controlling the operation of the bucket cylinder 15 alone, the hydraulic oil from the second hydraulic pump 3 is introduced through the parallel passage 12a and the tandem passage, so that the excessively generated when passing only through the parallel passage 12a. Pressure loss can be reduced.

On the other hand, when simultaneously operating the boom lowering operation and other work devices such as a bucket, the second center bypass passage 12 is closed by the boom lowering control spool to supply hydraulic oil to the bucket cylinder 15. The passage is provided only through the parallel passage 12a. In this case, a sufficient flow path cannot be secured by the wired control valve installed in the parallel flow path 12a, causing excessive pressure loss, thereby causing energy loss.

In addition, although the variable control valve (refer FIG. 2) may be provided as the throttling device 24 of the parallel flow path 12a mentioned above, such a throttling device also has a limitation in ensuring sufficient flow path.

According to an embodiment of the present invention, when operating a work device having a different operating pressure at the same time as in a boom-down operation and a bucket drive, the operating oil is introduced into the bucket control valve through the parallel flow path and the tandem flow path to be generated inside the control valve. It is associated with a work machine drive control system for construction machinery that reduces energy loss by reducing unnecessary pressure losses, thereby increasing hydraulic system efficiency.

Work device drive control system for construction machinery according to an embodiment of the present invention,

Engine,

Variable displacement first and second hydraulic pumps and pilot pumps connected to the engine,

A swing control valve installed in the first center bypass passage of the first hydraulic pump and connected to the parallel flow path, respectively, to control the swing motor, an arm control valve to control the arm cylinder, and a travel control valve to control the left travel motor. Wow,

A boom control valve for controlling the boom cylinder, a bucket control valve for controlling the bucket cylinder, and a traveling control valve for controlling the right traveling motor, respectively installed in the second center bypass passage of the second hydraulic pump and connected to the parallel flow path. Wow,

A pressure generator for outputting a control signal corresponding to the manipulated variable;

A bleed flow path formed in the boom lower side control spool of the boom control valve and maintaining the open state without blocking the second center bypass passage even when the boom control valve is switched to lower the boom by operating the pressure generator;

A center bypass switching valve installed at the downstreammost side of the second center bypass passage and switched by a control signal pressure for switching the boom control valve;

When operating a boom down operation and a work device having a different operating pressure at the same time, the working oil from the second hydraulic pump is introduced into the control valve through the parallel channel and the tandem channel connected to the second center bypass passage.

According to a preferred embodiment, the work device described above is a bucket and the control valve controlling the work device is a bucket control valve.

Construction device work control device drive control system according to an embodiment of the present invention configured as described above has the following advantages.

When operating work tools with different operating pressures simultaneously, such as in boom-down operation and bucket operation, the hydraulic fluid is introduced into the bucket control valve through the parallel and tandem flow paths (the flow rate as the flow rate passes along the tandem flow path). The energy loss can be reduced by reducing the pressure loss generated inside the control valve.

1 is a hydraulic circuit diagram of a control device driving control system for a construction machine according to the prior art,

Figure 2 is an enlarged view of the main portion extract of the priority control valve applied to the work machine drive control system for construction machinery according to the prior art,

3 is a hydraulic circuit diagram of a control system for driving a work device for a construction machine according to an embodiment of the present invention;

Figure 4 is an enlarged view of the main portion of the priority control valve in the construction machine work device drive control system according to an embodiment of the present invention.

One; engine

2; 1st hydraulic pump

3; 2nd hydraulic pump

4; Pilot pump

5; Center 1 bypass passage

6; Turning motor

7,9,11,14,16,18; Control valve

8; Arm cylinder

10,17; Driving motor

13; Boom cylinder

15; Bucket cylinder

19,20; Pressure generator

25; Bleed euro

26; Center bypass switching valve

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to explain in detail enough to enable those skilled in the art to easily carry out the invention, and thus the present invention. It is not intended that the technical spirit and scope of the invention be limited.

3 to 4 is a work machine driving control system for a construction machine according to an embodiment of the present invention,

The engine 1,

Variable displacement first and second hydraulic pumps (hereinafter referred to as " first and second hydraulic pumps " and pilot pumps 4) connected to the engine 1,

A swing control valve 7 installed in the first center bypass passage 5 of the first hydraulic pump 2 and connected to the parallel flow passage 5a to control the driving of the swing motor 6, and an arm cylinder ( 8) an arm control valve 9 for controlling driving, a travel control valve 11 for controlling driving of the left traveling motor 10,

A boom control valve 14a installed in the second center bypass passage 12 of the second hydraulic pump 3 and connected to the parallel passage 12a to control the boom cylinder 13 driving, and a bucket cylinder ( 15) a bucket control valve 16 for controlling the drive, a travel control valve 18 for controlling the drive of the right traveling motor 17,

Pressure generators

19 and 20 for outputting a control signal corresponding to the manipulated variable;

The second center bypass passage 12 is formed in the boom lower side control spool of the boom control valve 14a and also when the boom control valve 14a is switched so that the boom is turned down by the operation of the pressure generator 19. A bleed flow path 25 which is kept open without blocking;

A center bypass switching valve 26 is provided on the downstream side of the second center bypass passage 12 and is switched by a control signal pressure for switching the boom control valve 14a.

When simultaneously operating a boom down operation and a work device having a different operating pressure (an bucket is referred to as an example), the parallelism in which the hydraulic oil from the second hydraulic pump 3 is connected to the second center bypass passage 12 It is made to flow into the bucket control valve 16 through the flow path (12a) and the tandem flow path.

At this time, it is formed in the boom lower side control spool of the boom control valve 14a described above, and even when the boom control valve 14a is switched to lower the boom, the second center bypass passage 12 is opened without being blocked. A bleed flow path 25 which maintains a state,

The configuration except for the center bypass switching valve 26 provided on the downstream side of the second center bypass passage 12 and switched by the control signal pressure for switching the boom control valve 14a is shown in FIG. Since the configuration of the work device drive control system is the same, detailed descriptions of their configuration and operation are omitted, and the reference numerals for the overlapping components are the same.

Hereinafter, with reference to the accompanying drawings, an example of the use of the drive control system for a work machine construction equipment according to an embodiment of the present invention will be described in detail.

3 to 4, when simultaneously operating the boom down operation and the bucket drive, the pilot signal pressure from the pilot pump 4 is reduced by the operation of the pressure generator 19 described above. The boom control valve 14a is switched to the right direction on the drawing via. Therefore, the hydraulic oil discharged from the second hydraulic pump 3 is supplied to the small chamber of the boom cylinder 13 via the rod check valve 22 and the boom control valve 14a. At the same time, the hydraulic oil flowing out of the large chamber of the boom cylinder 13 is returned to the hydraulic tank T via the boom control valve 14a and the back pressure check valve 23. Therefore, the boom cylinder 13 is contracted and driven so that the boom can be lowered.

At this time, a part of the flow rate flowing out of the large chamber of the boom cylinder 13 due to the pressure generated by the back pressure check valve 23 is a regeneration line formed in the boom lower side control spool (refer to the boom control valve 14a). Through the small chamber of the boom cylinder 13 is reproduced.

On the other hand, the hydraulic oil discharged from the second hydraulic pump 3 passes through the bleed flow path 25 formed in the boom lower side control spool of the second center bypass passage 12-boom control valve 14a, and passes through the bucket control valve. It is supplied to the inlet side of 16. Therefore, the rod check valve 27 of the bucket control valve 16 is connected to the spool passage of the bucket control valve 16. On the other hand, the flow rate via the priority control valve installed in the parallel flow path 12a joins with the flow rate through the load check valve 27 and flows into the spool of the bucket control valve 16.

Therefore, when simultaneously operating the boom and the bucket having different operating pressures, the flow rate from the second hydraulic pump 3 flows into the spool of the bucket control valve 16 through the parallel flow passage 12a. At the same time, the flow rate from the second hydraulic pump 3 flows into the spool of the bucket control valve 16 also through the second center bypass passage 12. As a result, the pressure loss is reduced by the flow rate flowing through the second center bypass passage 12 to the spool of the bucket control valve 16 (This pressure loss reduction may be equally applied to the travel control valve 18. ).

According to the control system for a work machine drive device according to an embodiment of the present invention as described above, when operating a work device having a different operating pressure at the same time, such as in the boom down operation and bucket drive, parallel and tandem flow path Through the hydraulic fluid flows into the bucket control valve through it can reduce the pressure loss generated in the control valve to increase the hydraulic system efficiency.

Claims

Engine,

A variable displacement first and second hydraulic pump and a pilot pump connected to the engine;

A swing control valve installed in a first center bypass passage of the first hydraulic pump and connected to a parallel flow path, respectively, for controlling a swing motor, an arm control valve for controlling an arm cylinder, and a travel control for controlling a left travel motor; With the valve,

A boom control valve installed in the second center bypass passage of the second hydraulic pump and connected to the parallel flow path, respectively, to control the boom cylinder, the bucket control valve to control the bucket cylinder, and the travel control to control the right driving motor. With the valve,

A pressure generator for outputting a control signal corresponding to the manipulated variable;

A bleed flow path formed in the boom lower side control spool of the boom control valve and maintaining an open state without blocking the second center bypass passage during switching of the boom control valve so as to lower the boom by manipulating a pressure generator;

A center bypass switching valve disposed at the downstreammost side of the second center bypass passage and switched by a control signal pressure for switching the boom control valve;

When operating a boom down operation and a work device having a different operating pressure at the same time, the hydraulic oil from the second hydraulic pump is introduced into the control valve through a parallel channel and a tandem channel connected to the second center bypass passage. Characterized in that the work machine drive control system for construction machinery.
The system of claim 1, wherein the work device is a bucket, and the control valve for controlling the work device is a bucket control valve.