KR20100056110A - Hydraulic circuit for construction machinery - Google Patents

Abstract

PURPOSE: A hydraulic circuit for construction equipment is provided to minimize power loss of construction equipment by independently supplying hydraulic fluid to equipment, and to precisely control the position of the equipment. CONSTITUTION: A hydraulic circuit for construction equipment comprises a first control valve(130) for a first work, a first control valve(150) for a second work, a second control valve(140) for the first work, a second control valve(160) for the second work, and a separation unit(170). The first control valve for the first work and the second control valve for the second work control the flowing direction of hydraulic fluid supplied to a first working machine(110). The first control valve for the second work and the second control valve of the first work control the flowing direction of hydraulic fluid supplied to a second working machine(120). The separation unit switches the second control valves to neutral positions(141,161) or transfer positions(142,162,163).

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 the like, and relates to a hydraulic circuit of construction machinery that can be efficiently used for a job requiring fine position control of a work device such as ground leveling work or crane work.

In general, construction machinery such as excavators perform a variety of tasks, such as excavation, transport, loading. Most of these tasks have to deal with large workloads or require fast work speeds. Therefore, the hydraulic oil discharged from the plurality of pumps is joined and supplied to the boom cylinder and the arm cylinder.

As an example, the boom first speed control valve controls the flow direction of the hydraulic oil discharged from the first pump and supplies it to the boom cylinder, and the boom second speed control valve controls the flow direction of the hydraulic oil discharged from the second pump to the boom cylinder. Supply. The arm 1 speed control valve controls the flow direction of the hydraulic oil discharged from the second pump and supplies it to the arm cylinder, and the arm 2 speed control valve controls the flow direction of the hydraulic oil discharged from the first pump and supplies it to the arm cylinder. do.

That is, the hydraulic oil discharged from the first pump is supplied to the boom cylinder and the arm cylinder through the boom 1 speed control valve and the arm 2 speed control valve, respectively, and the hydraulic oil discharged from the second pump is the arm 1 speed control valve and the boom 2. It is supplied to each of the arm cylinder and the boom cylinder through each speed control valve.

However, the hydraulic circuit as described above is a structure in which the boom cylinder and the arm cylinder are divided by the hydraulic oil discharged from one pump, and the flow rate of the hydraulic oil supplied to the boom cylinder and the arm cylinder varies according to the load applied to the boom and the arm. For example, when a large load is applied to the boom, the flow rate of the hydraulic oil supplied to the arm cylinder is increased while the flow rate of the hydraulic oil supplied to the boom cylinder is vice versa and vice versa.

As such, the conventional hydraulic circuit may vary the flow rate or pressure of the hydraulic oil supplied to the other work machine according to the load of one work machine, and thus is useful for a job requiring high driving speed of the boom and the arm, but the flattening work or the crane work As such, it is difficult to control the fine position of the boom and the arm.

In addition, since the pressure of the hydraulic oil discharged from the pump is formed based on the pressure of the cylinder of the heavy work machine among the boom and the arm, the hydraulic oil of the pressure of the lower load is supplied to the cylinder of the lower load, thereby causing a throttle loss. This will occur. This throttle loss eventually leads to power loss of the construction machine, thereby lowering fuel economy.

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 not only reduce power loss of the construction machine but also facilitate the precise position control of a work device. .

Hydraulic circuit of the construction machine according to the present invention for achieving the object as described above, the first speed control for the first operation to control the flow direction of the hydraulic oil discharged from the first pump (P1) to supply to the first work machine 110 Valve 130; A first speed control valve 150 for a second operation that controls a flow direction of the hydraulic oil discharged from the second pump P2 and supplies the same to the second work machine 120; In the conversion position 142 and the first working device 110, the hydraulic oil discharged from the second pump P2 is discharged from the first pump P1 and joined with the hydraulic oil supplied to the first working device 110. A second speed control valve 140 for a first operation having a neutral position 141 for supplying only hydraulic oil discharged from the first pump P1; Conversion positions 162 and 163 and the second work machine for joining the hydraulic oil discharged from the first pump P1 to the hydraulic oil discharged from the second pump P2 and supplied to the second work machine 120. 120, a second operation control valve 160 having a neutral position (161) for supplying only the hydraulic oil discharged from the second pump (P2); And separating units 170 and 270 for switching the first and second work speed control valves 140 and 160 to the neutral positions 141 and 161 or the conversion positions 142 and 162. 370 and 470.

According to an embodiment of the present invention, the separation unit 170 may include: a separation switch 174 for generating the separation signal; And first and second operation units 101 and 102 for generating signal pressure for driving the first and second work machines 110 and 120 and the second speed control valve 140 for the first and second work. Each signal line is installed in each signal line 101a, 102a, 102b connecting each of the hydraulic pressure units 140a, 160a, 160b of the 160 to the signal lines generated by the separation switch 174. Signal blocking valves 171, 172, and 173 for selectively applying the signal pressures of 101a, 102a, and 102b to the hydraulic pressure units 140a, 160a, and 160b.

According to another embodiment of the present invention, the separation unit 270 includes: a separation switch 274 for generating the separation signal; And a signal transmission unit is connected to each of the signal applying units 240a, 260a, and 260b of the first and second work speed control valves 140 and 160 for the first and second operations. When generated, a blocking signal is applied to each of the signal applying units 240a, 260a, and 260b so that each of the first and second work speed control valves 140 and 160 is converted into a neutral position 141 and 161. The control unit 271 is applied.

According to another embodiment of the present invention, the separation unit 370, 470 is a work pattern signal generator 372 for generating a signal for the work pattern of the first and second work machines 110, 120 472; And signal transmission parts 240a, 260a, and 260b of the first and second work speed controller valves 140 and 160 for signal transmission, and the work pattern signal generator 372 ( A current work pattern is calculated from the signal generated from the signal 472, and the first work and the second work are compared with the calculated current work pattern and the preset reference work pattern. Control parts 371 and 471 for applying a signal to each of the signal applying parts 240a, 260a and 260b so that each of the working 2-speed control valves 140 and 160 is converted into the neutral positions 141 and 161. It includes.

Here, the work pattern signal generator 372 may include first and second manipulators 372a and 372b for generating signals for driving the first and second work machines 110 and 120. The controller 371 may calculate the current work pattern from signals generated from the first and second manipulation units 372a and 372b.

In addition, the first work machine 110 is a boom cylinder 110 for driving the boom 103, the second work machine 120 is an arm cylinder 120 for driving the arm 104, the work The pattern signal generator 472 may include a first sensor 472a for detecting a position of the boom 103; And a second sensor 472b for detecting the position of the arm 104, wherein the controller 471 is configured to present a current job from information about the position of the boom 103 and the arm 104. FIG. The pattern can be calculated.

According to the problem solving means as described above, the hydraulic oil discharged from the first and the second pump (P1) (P2) by the separation unit converts the second-speed control valve for the first and second operation to the neutral position is the first And by blocking the supply to each work machine through the second working two-speed control valve, the hydraulic oil discharged from each pump can be supplied to each work machine independently, thereby enabling precise position control of each work machine.

In addition, by independently supplying hydraulic oil discharged from each pump by the separating unit to each work machine, it is possible to prevent unnecessary high pressure hydraulic oil from being supplied to the work machine, thereby minimizing power loss of the construction machine. .

In addition, the convenience of operation of the construction machine is greatly increased by the control unit of the separation unit automatically calculating and controlling whether the current work pattern is calculated and whether the circuit is to be separated or joined.

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

1, the hydraulic circuit of the construction machine according to the first embodiment of the present invention is the first speed control valve 130 for the first work, the first speed control valve 150 for the second work, the second speed for the first work The control valve 140, the 2nd speed control valve 160 for a 2nd operation, and the isolation unit 170 are included.

The first work speed control valve 130 and the first work speed control valve 140 are converted by a signal generated by the first operation unit 101 and supplied to the first work machine 110. Control the flow direction.

The first speed control valve 150 for the second work and the second speed control valve 160 for the second work are converted by a signal generated by the second operation unit 102 and supplied to the second work machine 120. Control the flow direction.

In this embodiment, in order to help the understanding of the spirit of the present invention, the first cylinder 110 to the boom cylinder 110, the second cylinder 120 to the arm cylinder 120, the first speed control for the first operation The valve 130 and the second speed control valve 140 for the first operation are used to control the boom first speed control valve 130 and the boom second speed control valve 140, and the first speed control valve 150 for the second operation and the second operation two. As the speed control valve 160, the arm 1 speed control valve 150 and the arm 2 speed control valve 160 are illustrated and demonstrated. However, the idea of the present invention is not specifically applied to the boom cylinder and the arm cylinder, but may be applied to other work machines.

One side of the boom 1 speed control valve 130 is connected to the first pump (P1), the other side is connected to the boom cylinder 110, by controlling the flow direction of the hydraulic oil discharged from the first pump (P1) Supply to the boom cylinder (110). The boom first speed control valve 130 is applied to the signal pressure generated from the first operation unit 101 is applied to each of the first and second hydraulic pressure unit (130a, 130b) is converted, such a boom first speed control valve ( By the conversion of 130, the flow direction of the hydraulic oil supplied to the boom cylinder 110 is controlled.

The first arm control valve 150 is connected to one side of the second pump (P2), the other side is connected to the arm cylinder 120, by controlling the flow direction of the hydraulic oil discharged from the second pump (P2) Supply to the arm cylinder 120. The arm 1 speed control valve 150 is applied to any one of the first and second hydraulic pressure unit (150a, 150b) is converted from the signal pressure generated from the second operation unit 102, such arm 1 speed control By the change of the valve 150, the flow direction of the hydraulic oil supplied to the arm cylinder 120 is controlled.

One side of the boom 2 speed control valve 140 is connected to the second pump (P2), the other side is connected to the rising side (110a) of the boom cylinder 110 to the hydraulic fluid discharged from the second pump (P2) Optionally supplied to the rising side (110a) of the boom cylinder (110). More specifically, the boom 2 speed control valve 140 is a neutral position 141 and the hydraulic oil of the second pump (P2) to block the supply of the hydraulic oil of the second pump (P2) to the boom cylinder (110) It is converted to any one of the conversion positions 142 which allow the cylinder 110 to be supplied to selectively supply the hydraulic oil of the second pump P2 to the boom cylinder 110.

In addition, the boom 2-speed control valve 140 includes a hydraulic pressure unit 140a connected to the rising signal line 101b of the first operation unit 101. If the rising signal pressure from the first operation unit 101 is not applied to the hydraulic unit 140a, the boom 2-speed control valve 140 maintains the neutral position 141, and the first operation unit 101 When the rising signal pressure generated by the rising signal line 101b is applied to the hydraulic pressure unit 140a, the boom 2-speed control valve 140 is converted to the change position 142 to the second pump P2. The hydraulic oil discharged from the gas is supplied to the rising side 110a of the boom cylinder 110. In this state, the hydraulic oil discharged from the first and second pumps P1 and P2 are all supplied to the rising side 110a of the boom cylinder 110.

The arm 2 speed control valve 160 has one side connected to the first pump (P1), the other side is connected to the arm cylinder 120 to selectively discharge the hydraulic oil discharged from the first pump (P1) the arm cylinder ( 120). More specifically, the arm 2 speed control valve 160 is the neutral position 161 and the hydraulic oil of the first pump (P1) to block the supply of the hydraulic oil of the first pump (P1) to the arm cylinder 120 It is converted to any one of the conversion positions 162 and 163 allowing the supply to the cylinder 120 to selectively supply the hydraulic oil of the first pump P1 to the arm cylinder 120.

In addition, the arm 2 speed control valve 160 is the first and second hydraulic pressure unit (160a) (160b) connected to each of the rising signal line (102a) and the falling signal line (102b) of the second operation unit (102) It is provided. When the rising and falling signal pressure from the second operation unit 102 is not applied to the hydraulic units 160a and 160b, the arm 2 speed control valve 160 maintains the neutral position 161. 2 When the rising or falling signal pressure generated from the operation unit 102 is applied to any one of the pressure receiving units 160a and 160b through the rising signal line 101b or the falling signal line 102b, the arm 2 speed control is performed. The valve 160 is converted to any one of the conversion positions 162 and 163 to supply the hydraulic oil discharged from the first pump P1 to the arm cylinder 120. In this state, all of the hydraulic oil discharged from the first and second pumps P1 and P2 is supplied to the arm cylinder 120.

Referring to the hydraulic circuit as described above with reference to the pump, the hydraulic oil discharged from the first pump (P1) is the boom cylinder 110 through each of the boom 1 speed control valve 130 and the arm 2 speed control valve 160. And the hydraulic fluid distributed to the arm cylinder 120 and discharged from the second pump P2, the arm cylinder 120 and the arm first speed control valve 150 and the boom second speed control valve 140 respectively. It is distributed and supplied to the boom cylinder 110.

For this reason, when the loads applied to the boom 103 and the arm 104 are different, variations in the flow rate of the hydraulic oil supplied to the boom cylinder 110 and the arm cylinder 120 occur. Therefore, precise position control of the boom 103 and the arm 104 is difficult, and operations requiring detailed position control such as a flattening operation or a crane operation are inefficiently performed.

In addition, when a large workload is applied to either the boom 103 or the arm 104, a small workload is applied because the pressure of the hydraulic oil discharged from the pump is formed corresponding to the working machine side to which the large workload is applied. Loss of work occurs in the losing work machine, which causes power loss of the construction machine. For this reason, the hydraulic oil discharged from each of the pumps (P1) (P2) through the separation unit 170 to be independently supplied to two or more working machines. Hereinafter, the separation unit 170 will be described in detail.

The separation unit 170 may include a separation switch 174 that selectively generates a separation signal, and the boom 2-speed control valve 140 and the arm 2-speed control valve 160 according to a signal generated from the separation switch 174. Signal blocking valves 171, 172 and 173 for controlling the conversion of the "

The separation switch 174 may be provided inside the cab for easy operation by the driver, and various known on / off switches may be used.

The signal blocking valves 171, 172, and 173 include first to third signal blocking valves 171, 172, and 173.

The first signal blocking valve 171 is installed on the rising signal line 101b of the first operation unit 101 to apply the rising signal pressure to the hydraulic pressure unit 140a of the boom 2 speed control valve 140. Selectively block The first signal blocking valve 171 is connected to the separation switch 174 so that when the separation switch 174 is ON, that is, when a separation signal is generated from the separation switch 174, current is supplied. The rising signal line 101b of the first operation unit 101 is blocked, whereby the signal pressure of the rising signal line 101b is not applied to the hydraulic pressure unit 140a of the boom 2-speed control valve 140. Will not. Therefore, the boom 2-speed control valve 140 blocks the hydraulic oil discharged from the second pump P2 from being supplied to the boom cylinder 110, whereby the hydraulic oil discharged from the second pump P2 is an arm. Only the cylinder 120 can be supplied. On the contrary, when the separation switch 174 is turned off, the hydraulic pressure unit 140a of the boom 2 speed control valve 140 is connected to the rising signal line 101b. Therefore, when the rising signal pressure is applied to the hydraulic pressure unit 140a from the first operation unit 101 via the rising signal line 101b, the hydraulic oil discharged from the second pump P2 rises in the boom cylinder 110. It can be supplied to the side (110a).

The second signal blocking valve 172 is installed on the rising signal line 102a of the second operation part 102 to raise the signal pressure to the first hydraulic pressure part 160a of the arm 2 speed control valve 160. It selectively blocks the application. The second signal blocking valve 172 is connected to the separation switch 174 so that when the separation switch 174 is ON, that is, when a separation signal is generated from the separation switch 174, a current is supplied. The rising signal line 102a of the second operation unit 102 is blocked, whereby the signal pressure of the rising signal line 101b is applied to the first hydraulic pressure unit 160a of the arm second speed control valve 160. It is not authorized.

The third signal blocking valve 173 is installed on the lower signal line 102b of the second operation part 102 to lower the signal pressure to the second hydraulic pressure part 160b of the arm 2 speed control valve 160. It selectively blocks the application. The third signal blocking valve 173 is connected to the separation switch 174 so that when the separation switch 174 is turned ON, that is, when a separation signal is generated from the separation switch 174, a current is supplied. The rising signal line 102a of the second operation unit 102 is blocked, whereby the signal pressure of the falling signal line 102b is applied to the second pressure receiving unit 160b of the arm 2 speed control valve 160. It is not authorized.

As such, when the second and third signal blocking valves 172 and 173 block each of the rising signal line 102a and the falling signal line 102b of the second operation part 102, the arm 2 speed The control valve 160 blocks the hydraulic oil discharged from the first pump P1 from being supplied to the arm cylinder 120, whereby the hydraulic oil discharged from the first pump P1 is controlled by the boom first speed control valve 130. It can be supplied only to the boom cylinder (110) through.

On the contrary, when the disconnecting switch 174 is turned off, each of the pressure receiving portions 160a and 160b of the arm 2 speed control valve 160 may be respectively the rising signal line 102a and the falling signal line 102b. Is connected to. Therefore, when the signal pressure is input from the second operation unit 102 via the rising signal line 102a or the falling signal line 102b, the hydraulic oil discharged from the second pump P2 may be supplied to the arm cylinder 120. It becomes possible.

As described above, the hydraulic switch discharged from the first and second pumps P1 and P2 may be joined by turning off the separation switch 174 to supply the boom cylinder 110 and the arm cylinder 120. When the separation switch 174 is turned on to generate a separation signal while efficiently performing a work requiring a working speed, the hydraulic oil discharged from the first pump P1 is supplied only to the boom cylinder 110, and the second The hydraulic oil discharged from the pump P2 can be supplied only to the arm cylinder 120, so that not only the work requiring fine position control such as flattening work or crane work can be efficiently performed, but also throttle loss ) Can reduce power loss.

As an example, as shown in FIG. 2, in the case of a job of moving inward while keeping the bucket 105 horizontal, a large workload is applied to the arm cylinder 120, but a small workload is applied to the boom cylinder 110. All. In this case, as shown in FIG. 3, the hydraulic oil pressures of the first pump P1 and the second pump P2 rise almost equally in the related art. However, according to this embodiment, only the pressure (indicated by the solid line) of the second pump P2 for supplying the hydraulic oil to the arm cylinder 120 is raised, and the first pump for supplying the hydraulic oil to the boom cylinder 110. The pressure (indicated by the dashed line) of P1 is almost the same as that at no load. From this, it can be seen that according to the present embodiment, power loss can be minimized.

In addition, as shown in FIG. 4, a large load is applied to the arm cylinder 120 and a large flow rate of hydraulic oil is supplied to the boom cylinder 110. For this reason, in order to supply the required flow rate to the arm cylinder 120, the operation angle of the 2nd operation part 102 which is an arm operation part becomes large gradually. However, according to the present embodiment, each of the pumps P1 and P2 supplies hydraulic oil to the cylinders 110 and 120 independently, so that the operation angle of the second operation unit 102, which is the arm operation unit, is not increased. do. It can be seen that the position control of the boom and the arm can be precisely thereby.

The same components as those of the first embodiment of the components of the second to fourth embodiments described below are given the same reference numerals.

5 is a view schematically showing a hydraulic circuit according to a second embodiment of the present invention.

In the second embodiment of the present invention, each control valve 130, 140, 150, 160 has been illustrated a form that can be electronically controlled. Therefore, the signal applying unit 230a, 230b, 240a, 250a, 250b, 260a, 260b of each control valve 130, 140, 150, 160 is composed of an electromagnetic proportional pressure reducing valve. The control unit 271 is electrically connected to each of the signal applying units 230a, 230b, 240a, 250a, 250b, 260a, and 260b.

The separation unit 270 according to the second embodiment of the present invention includes a separation switch 274 and a controller 271.

The control unit 271 is connected to each of the signal applying unit 240a, 260a, 260b of the first and second work speed control valves 140 and 160 for signal transmission, and the separation switch 274. When the ON signal is turned on and the separation signal is input, each signal applying unit 240a converts each of the first and second work speed control valves 140 and 160 into the neutral positions 141 and 161. A signal is applied to (260a) and 260b.

On the other hand, when the separation switch 274 is turned off (OFF) and the joining signal is input, the controller 271 receives the first and second signals according to signals applied from the first and second manipulation units 101 and 102. The conversion signal is input to the signal applying units 240a, 260a, and 260b of the working 2-speed control valve 140 and 160.

As described above, even when the control valve 130, 140, 150, 160 is electronically controlled, the same operation and effect as the first embodiment of the present invention occurs, so a description thereof will be omitted.

6 and 7 are views schematically showing a hydraulic circuit of a construction machine according to a third embodiment of the present invention. 6 and 7, in the third embodiment of the present invention, the disconnect switch 274 of the second embodiment of the present invention is deleted and automatically determined by the controller 371.

More specifically, the controller 371 calculates the current work pattern, compares the calculated current work pattern with a preset work pattern, and separates the circuit only when they match each other. That is, the separation unit 370 according to the third embodiment of the present invention includes a work pattern generating unit and a control unit 271.

The work pattern generator 372 includes first and second manipulation units 372a and 372b. That is, the controller 371 stores a signal input to the controller 371 from the first and second manipulation units 372a and 372b for a predetermined time, and stores the stored first and second manipulation units 372a and 372b. The current work pattern is calculated from the signals input from the step S10 and the step S20.

The controller 371 compares the current work pattern with a preset reference work pattern, and determines whether the current work pattern matches the reference work pattern as a result of the comparison (S30). As a result of the determination, when both working patterns match, the circuit is separated by maintaining each of the boom 2-speed control valve 140 and the arm 2-speed control valve 160 in the neutral positions 141 and 161 (S40). On the other hand, if the two working patterns do not match, each of the boom 2 speed control valve 140 and the arm 2 speed control valve 160 is converted according to the signals input from the first and second operation portions 372a, 372b. Joining the circuit (S50). Here, the term 'circuit separation' means that the hydraulic oil discharged from each of the pumps P1 and P2 is independently supplied to each of the cylinders 110 and 120, and the term “circuit joining” is discharged from one pump. It means that the hydraulic oil is supplied to the plurality of cylinders (110, 120).

The reference work pattern may mean a work pattern such as a planarization work or a crane work, and a plurality of reference work patterns may be set.

As such, the controller 371 automatically determines whether the circuit is separated or joined, so that the convenience of the construction machine can be further increased.

8 is a view schematically showing a hydraulic circuit of a construction machine according to a fourth embodiment of the present invention. Referring to FIG. 8, the fourth embodiment of the present invention differs from the third embodiment in the work pattern generator 472, and the rest of the configuration is the same.

The work pattern generator 472 according to the fourth embodiment of the present invention includes first to third sensors 472a and 472b for detecting positions of the boom 103, the arm 104, and the bucket 105. 472c. The plurality of sensors 472a, 472b, 472c may be angle sensors or gyro sensors for sensing angles of the boom 103, the arm 104 and the bucket 105, and may also be used for each cylinder 110 ( 120 and 121 may be configured as a displacement sensor for measuring the rod length. That is, a plurality of sensors 472a, 472b, 472c may be used as long as various types of sensors can sense the locations of the boom 103, the arm 104, and the bucket 105, and various places. Can detect variables

Information about the positions of the boom 103, the arm 104, and the bucket 105 output from the plurality of sensors 472a, 472b, 472c is input to the controller 471, and the controller 471 is After storing the information on each location for a certain time, the current work pattern is calculated therefrom.

Since the control process is the same as the third embodiment of the present invention, a detailed description thereof will be omitted. In the present exemplary embodiment, three sensors 472a, 472b, and 472c are illustrated. Unlike the present exemplary embodiment, the third sensor 472a, 472b, and 472c is used to detect the position of the boom 103 among the plurality of sensors 472a, 472b, and 472c. Only the second sensor 472b for sensing the position of the first sensor 472a and the arm 104 may be configured.

1 is a view schematically showing a hydraulic circuit of a construction machine according to a first embodiment of the present invention;

2 is a view schematically showing a process of the flattening operation of the bucket,

3 is a graph schematically showing a change in the hydraulic oil pressure of the first and second pumps occurring in the planarization operation process shown in FIG. 2 for comparing the conventional construction machinery hydraulic circuit with the hydraulic circuit of the first embodiment;

4 is a graph schematically showing the operating angles of the first and second operation units occurring in the planarization operation process shown in FIG. 2 to compare the conventional construction machinery hydraulic circuit with the hydraulic circuit of the first embodiment;

5 is a view schematically showing a hydraulic circuit of a construction machine according to a second embodiment of the present invention;

6 is a view schematically showing a hydraulic circuit of a construction machine according to a third embodiment of the present invention;

7 is a flow chart for explaining the operation of the hydraulic circuit of the construction machine shown in FIG.

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

<Description of Major Reference Marks in Drawings>

P1, P2; First and second pumps 110, 120; 1st and 2nd working machine

130; 1 speed control valve for 1st operation, boom 1 speed control valve

140; 2-speed control valve for 1st operation, boom 2-speed control valve

150; 1 speed control valve for 2nd operation, 1 speed control valve for arm

160; 2 speed control valve for 2nd operation, 2 speed control valve for arm

170, 270, 370, 470; Separation units 174, 274; Disconnect switch

171, 172, 173; 1st to 3rd signal blocking valve

271, 371, 471; Control units 372 and 472; Work pattern generator

Claims (6)

A first work speed control valve 130 for controlling the flow direction of the hydraulic oil discharged from the first pump P1 to supply the first work machine 110 to the first work machine 110; A first speed control valve 150 for a second operation that controls a flow direction of the hydraulic oil discharged from the second pump P2 and supplies the same to the second work machine 120; In the conversion position 142 and the first working device 110, the hydraulic oil discharged from the second pump P2 is discharged from the first pump P1 and joined with the hydraulic oil supplied to the first working device 110. A second speed control valve 140 for a first operation having a neutral position 141 for supplying only hydraulic oil discharged from the first pump P1; Conversion positions 162 and 163 and the second work machine for joining the hydraulic oil discharged from the first pump P1 to the hydraulic oil discharged from the second pump P2 and supplied to the second work machine 120. 120, a second operation control valve 160 having a neutral position (161) for supplying only the hydraulic oil discharged from the second pump (P2); And Separation units 170 and 270 for switching the first and second work speed control valves 140 and 160 to neutral positions 141, 161 or conversion positions 142, 162 and 163. Hydraulic circuit of a construction machine, characterized in that it comprises a (370) (470). The method of claim 1, wherein the separation unit 170, A disconnect switch (174) for generating the disconnect signal; And First and second operation units 101 and 102 for generating signal pressure for driving the first and second work machines 110 and 120 and second speed control valves 140 for the first and second work. Each signal line (101a) (102a) (102b) connecting each of the pressure receiving parts (140a) (160a) (160b) of the 160 is installed in accordance with the signal generated from the separation switch (174). And signal blocking valves 171, 172, and 173 for selectively applying or blocking the signal pressures of the 101a, 102a, and 102b to the hydraulic units 140a, 160a, and 160b. Hydraulic circuit of construction machinery. The method of claim 1, wherein the separation unit 270, A disconnect switch 274 for generating the disconnect signal; And It is connected to each of the signal applying unit 240a, 260a, 260b of the first and second working speed control valves 140 and 160 for signal transmission, and to a signal generated from the separation switch 274. The signal applying unit 240a so that each of the first and second working second speed control valves 140 and 160 is switched to a neutral position 141, 161 or a conversion position 142, 162, 163. Hydraulic circuit of a construction machine, characterized in that it comprises a control unit (271) for applying or blocking a signal to (260a) (260b). The method of claim 1, wherein the separation unit 370, 470, Work pattern signal generators 372 and 472 for generating signals for work patterns of the first and second work machines 110 and 120; And Signal transmission parts 240a, 260a and 260b of the first and second work speed control valves 140 and 160 for signal transmission are connected to each other, and the work pattern signal generators 372 and 472 are connected. Calculating a current work pattern from a signal generated from the control panel, and comparing the calculated current work pattern with a preset reference work pattern and matching the current work pattern with a preset reference work pattern, Controls 371 and 471 for applying signals to the respective signal applying units 240a, 260a and 260b so that each of the second speed control valves 140 and 160 are converted into neutral positions 141 and 161. Hydraulic circuit of a construction machine comprising a. The method of claim 4, wherein The work pattern signal generator 372 includes first and second manipulation units 372a and 372b for generating a signal for driving the first and second work machines 110 and 120. The control unit (371) calculates the current working pattern from the signals generated from the first and second operation unit (372a) (372b), the hydraulic circuit of the construction machine. The method of claim 4, wherein The first work machine 110 is a boom cylinder 110 for driving the boom 103, the second work machine 120 is an arm cylinder 120 for driving the arm 104, The work pattern signal generator 472, A first sensor 472a for detecting a position of the boom 103; And A second sensor 472b for sensing the position of the arm 104, The control unit (471) is a hydraulic circuit of a construction machine, characterized in that for calculating the current working pattern from the information on the position of the boom (103) and the arm (104).

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