CN205276344U - Hydraulic control system and excavator - Google Patents

Abstract

The utility model discloses a hydraulic control system and excavator. Hydraulic control system includes the main valve, the main valve includes pressure oil oil inlet, oil drain port and being used for for the first work oil circuit of an execute component's first working chamber fuel feeding and oil return with for the second work oil circuit of an execute component's second working chamber fuel feeding and oil return, hydraulic control system is still including the oil return control valve that is used for controlling second working chamber oil return, the oil return control valve includes back pressure regulating valve, back pressure regulating valve has throttling arrangement, first hydraulic fluid port and second hydraulic fluid port, first hydraulic fluid port is connected with second work oil circuit, the second hydraulic fluid port is connected through connection work oil circuit and second working chamber, back pressure regulating valve has first work position, pass through the throttling arrangement intercommunication at its first hydraulic fluid port of back pressure regulating valve's first work position and second hydraulic fluid port. The utility model discloses the return oil pressure of an execute component's second working chamber can be increased when needing, the pressure oil regeneration of second working chamber can be promoted.

Description

Hydraulic control system and excavator

Technical field

The utility model relates to engineering machinery field, in particular to a kind of hydraulic control system and excavator.

Background technology

Excavator mainly comprise get off, turning device and equipment. The equipment of excavator comprises swing arm, bucket bar, scraper bowl. Excavator also comprises the hydraulic control system for controlling each equipment. Hydraulic control system is realized the control of swing arm, the bucket equipment such as bar, scraper bowl by control swing arm oil cylinder, the bucket power element such as rod oil cylinder and scraper bowl oil cylinder. In the hydraulic control system of excavator, the pressure oil that main pump exports respectively works through main valve to join and acts on compound action or the action separately that each power element realizes each equipment.

Excavator has the operating modes such as continuous excavation, grading operation, and the performance of digger operating device is had different requirement by different operating mode.

Wherein, excavator boom has refresh function in the interior time receiving, and in order to promote that regeneration can arrange bucket bar regeneration back pressure valve after bucket bar main valve, by increasing, bucket bar oil return loop back pressure improves bucket bar regenerative power to this bucket bar regeneration back pressure valve. Excavator is when excavating operation, and the bucket big cavity pressure of rod oil cylinder is greater than the bucket little cavity pressure of rod oil cylinder, and bucket bar loses regenerative power. Now, the rods circuit that struggles against just does not need oil return back pressure. Excavator grading operation operating mode is the compound action that bucket bar adduction and swing arm rise. Due to the effect of gravity, bucket bar adduction load pressure is less than swing arm rising load pressure. Now main pump to different load fuel feeding, and will throttle in hydraulic efficiency system at excavator, pressure oil can preferential flow to the low equipment of load pressure, thus reduce the action Harmony of excavator.

Fig. 1 be excavator in prior art hydraulic control system in the principle schematic of main valve. As shown in Figure 1, main valve comprises the first bucket bar control valve 1' and the 2nd bucket bar control valve 11', arranges back pressure valve 10' and promotes bucket bar regeneration, and carry out the load pressure divergence between balanced bucket bar and swing arm by fixing damper hole 3' after the 2nd bucket bar control valve 11'. In Fig. 1, P1, P2 and T represent the first pressure oil oil-in of main valve, the 2nd pressure oil oil-in and oil discharge outlet T respectively.

Realizing in process of the present utility model, designer finds, the hydraulic control system of the prior art has following weak point:

1, the bar regeneration back pressure valve 10' that struggles against is only for improving bucket bar regeneration back pressure, it does not have other effect, and utilization ratio is lower, adds main valve structure complicacy;

2, when excavator excavates operation, when the bucket big cavity pressure of bar is greater than bucket bar little cavity pressure, bucket bar can not regenerate, and now back pressure valve 10' does not play regeneration, can increase the bucket bar oil return pressure-losses on the contrary;

3, when excavator excavates operation, back pressure valve 10' increases bucket bar oil return back pressure, bucket bar digging force is reduced, affects digging efficiency;

4, owing to damper hole 3' size is fixed, the type of different tonnage being needed the damper hole choosing different size, versatility is poor;

5, the determination of the size of damper hole 3' needs the damper hole 3' by changing different size to carry out machine debugging checking, extends the R&D cycle of complete machine, and increases R&D costs;

6, when non-grading operation, damper hole 3' can increase the back pressure of main pump oil circuit, cause the first main pump to the first fuel feeding mouth P1 fuel feeding and inconsistent to the top hole pressure of the 2nd main pump of the 2nd fuel feeding mouth P2 fuel feeding, cause two pump horsepower Imbalance, increase system power and regulate difficulty;

7, when excavator operation, damper hole 3' can increase the system circuit pressure-losses, increases system radiating, causes power dissipation, and when especially excavating operation, power dissipation is the most serious.

Practical novel content

The purpose of this utility model is to provide a kind of hydraulic control system and excavator, it is intended to increase the oil return back pressure of the 2nd working chamber of the first power element when needed, it is possible to promote the pressure oil regeneration of the 2nd working chamber. Excavator is applied this hydraulic control system, it is intended to improve excavator power utilization rate, reduce oil consumption.

The utility model first aspect provides a kind of hydraulic control system, comprise main valve, described main valve comprises pressure oil oil-in, oil discharge outlet and for for the first working chamber fuel feeding of the first power element and the first working oil path of oil return be the 2nd working chamber fuel feeding of described first power element and the 2nd working oil path of oil return, selectively control in described first working oil path and described 2nd working oil path one is connected and another is connected with described oil discharge outlet described main valve with described pressure oil oil-in, described hydraulic control system also comprises the oil return control valve for controlling described 2nd working chamber oil return, described oil return control valve comprises back pressure regulating valve, described back pressure regulating valve has throttling set, first oil mouth and the 2nd oil mouth, first oil mouth of described back pressure regulating valve is connected with described 2nd working oil path, by connecting, working oil path is connected 2nd oil mouth of described back pressure regulating valve with described 2nd working chamber, described back pressure regulating valve has the first working position, its the first oil mouth of the first working position at described back pressure regulating valve is connected by described throttling set with the 2nd oil mouth.

Further, the aperture of described throttling set can regulate continuously.

Further, described throttling set is ratio throttling mouth.

Further, described back pressure regulating valve also has the 2nd working position, and its first oil mouth of the 2nd working position at described back pressure regulating valve is directly connected with the 2nd oil mouth.

Further, described back pressure regulating valve comprise control its first working position and the 2nd working position switching the first control end and the 2nd control end, wherein, the first control end of described back pressure regulating valve comprises pilot control opening, and described 2nd control end of described back pressure regulating valve comprises the first spring.

Further, described oil return control valve also comprises fast unloading valve, described fast unloading valve has the first oil mouth and the 2nd oil mouth, first oil mouth of described fast unloading valve connects with the described working oil path that is connected, 2nd oil mouth of described fast unloading valve is connected with described oil discharge outlet, and described fast unloading valve can control its first oil mouth and the break-make of the 2nd oil mouth.

Further, described fast unloading valve ratio can control the aperture of valve port when its first oil mouth is connected with the 2nd oil mouth.

Further, described hydraulic control system also comprises the first pressure transmitter and the 2nd pressure transmitter, described first pressure transmitter is for measuring the first pressure of described first working oil path, described 2nd pressure transmitter is for measuring the 2nd pressure of described connection working oil path, described fast unloading valve is further, a control end of described fast unloading valve comprises solenoid, described hydraulic control system also comprises control device, described first pressure transmitter, the solenoid of described 2nd pressure transmitter and described fast unloading valve is connected with described control device respectively, described control device is greater than solenoid described in described first pressure control at described 2nd pressure makes the first oil mouth of described fast unloading valve and the 2nd oil mouth disconnect, described control device is less than at described 2nd pressure or equals solenoid described in described first pressure control makes the first oil mouth of described fast unloading valve be connected with the 2nd oil mouth.

Further, the loculus of described bucket rod oil cylinder is by means of only described oil return control valve oil return.

Further, described first power element is the bucket rod oil cylinder of excavator, and described first working chamber is the big chamber of described bucket rod oil cylinder, and described 2nd working chamber is the loculus of described bucket rod oil cylinder.

Further, described main valve comprises the first bucket bar control valve and the 2nd bucket bar control valve, described pressure oil oil-in comprises the first pressure oil oil-in and the 2nd pressure oil oil-in, described first bucket bar control valve selectively controls described first working oil path and is connected and another is connected with described oil discharge outlet with described first pressure oil oil-in with in described 2nd working oil path, described 2nd bucket bar control valve selectively controls in described first working oil path and described 2nd working oil path and described 2nd pressure oil oil-in, it is connected and another is connected with described oil discharge outlet.

Further, described first bucket bar control valve and described first pressure oil oil-in between oil circuit on solid damper hole is not set.

Further, enter oil in the big chamber of described bucket rod oil cylinder and during the loculus oil return of the rod oil cylinder that struggles against, disconnecting and the oily mouth connection for being connected with the big chamber of described bucket rod oil cylinder of the bar control valve that struggled against with the described 2nd by check valve with described oil discharge outlet for the oily mouth being connected with the loculus of described bucket rod oil cylinder of described 2nd bucket bar control valve.

Further, described main valve also comprises for for the first working chamber fuel feeding of the 2nd power element and the 3rd working oil path of oil return with for being the 2nd working chamber fuel feeding of described 2nd power element and the 4th working oil path of oil return, described main valve selectively controls described 3rd working oil path and is connected and another is connected with described oil discharge outlet with described pressure oil oil-in with in described 4th working oil path.

Further, described main valve also comprises for the first working chamber fuel feeding of the 2nd power element and the 3rd working oil path of oil return with for being the 2nd working chamber fuel feeding of described 2nd power element and the 4th working oil path of oil return, described 2nd power element is the swing arm oil cylinder of described excavator, described main valve also comprises the first swing arm control valve and the 2nd swing arm control valve, described first swing arm control valve selectively controls described 3rd working oil path and is connected and another is connected with described oil discharge outlet with described first pressure oil oil-in with in described 4th working oil path, described 2nd swing arm control valve is for controlling described 3rd working oil path and the break-make of described 2nd pressure oil oil-in.

Further, described main valve and described oil return control valve become one.

The utility model second aspect provides a kind of excavator, comprises the hydraulic control system according to any one of the utility model first aspect.

Based on the hydraulic control system that the utility model provides, comprise main valve and oil return control valve, main valve comprises pressure oil oil-in, oil discharge outlet and for the first working chamber fuel feeding of the first power element and the first working oil path of oil return be the 2nd working chamber fuel feeding of the first power element and the 2nd working oil path of oil return, oil return control valve comprises back pressure regulating valve, back pressure regulating valve has throttling set, first oil mouth and the 2nd oil mouth, first oil mouth of back pressure regulating valve is connected with the 2nd working oil path, by connecting, working oil path is connected 2nd oil mouth of back pressure regulating valve with the 2nd working chamber, back pressure regulating valve has the first working position, its the first oil mouth of the first working position at back pressure regulating valve is connected by throttling set with the 2nd oil mouth. there is the throttling set of the oil return back pressure of the 2nd working chamber for controlling the first power element due to back pressure regulating valve, it is possible to increase the oil return back pressure of the 2nd working chamber of the first power element when needed, it is possible to promote the pressure oil regeneration of the 2nd working chamber. when the bucket rod oil cylinder that the first power element is excavator, it is possible to increase bucket rod oil cylinder loculus oil return back pressure, promote bucket rod oil cylinder loculus pressure oil regeneration, it is to increase excavator power utilization rate, reduce oil consumption. excavator is applied this hydraulic control system, then can improve excavator power utilization rate, reduce oil consumption.

By the detailed description of exemplary embodiment of the present utility model, further feature of the present utility model and advantage thereof being become clear referring to accompanying drawing.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide to of the present utility model it is further understood that the part of formation the application, and schematic description and description of the present utility model, for explaining the utility model, is not formed improper restriction of the present utility model. In the accompanying drawings:

Fig. 1 is the principle schematic of the main valve of the hydraulic control system of the excavator of prior art.

Fig. 2 is the main valve of the hydraulic control system of the excavator of the utility model specific embodiment and the principle schematic of oil return control valve.

Fig. 3 is the electric control principle schematic diagram of the fast unloading valve shown in Fig. 2.

Fig. 4 is the control schema of the fast unloading valve shown in Fig. 2.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that described embodiment is only the utility model part embodiment, instead of whole embodiments. It is explanation property to the description only actually of at least one exemplary embodiment below, never as to any restriction of the utility model and application or use. Based on the embodiment in the utility model, those of ordinary skill in the art are not making other embodiments all obtained under creative work prerequisite, all belong to the scope of the utility model protection.

Unless specifically stated otherwise, otherwise positioned opposite, the numerical expression of the parts set forth in these embodiments and step and numerical value do not limit scope of the present utility model. Simultaneously, it should be appreciated that for convenience of description, the size of each part shown in accompanying drawing is not draw according to the proportionlity of reality. Detailed discussion may not be done, but in the appropriate case, described technology, method and equipment should be regarded as authorizing a part for specification sheets for the known technology of person of ordinary skill in the relevant, method and equipment. In all examples with discussing shown here, any concrete value should be interpreted as being only exemplary, instead of as restriction. Therefore, other example of exemplary embodiment can have different values. It should be noted that: similar label and letter accompanying drawing below represents similar item, therefore, once a certain Xiang Yi accompanying drawing is defined, then does not need it to be further discussed in accompanying drawing subsequently.

For convenience of description, here can usage space relative terms, as " ... on ", " in ... top ", " at ... upper surface ", " above " etc., be used for the spatial relation described such as a device shown in the figure or feature and other devices or feature. Should be understood that, space relative terms is intended to the different azimuth in use or operation comprised except the orientation that device is described in the drawings. Such as, " in other devices or structure lower section " or " under other devices or structure " will be positioned as after if the device in accompanying drawing is squeezed, being then described as the device of " above other devices or structure " or " on other devices or structure ". Thus, exemplary term " in ... top " can comprise " in ... top " and " in ... lower section " two kinds of orientation. This device can also other different modes position rotating 90 degree or be in other orientation, and the space used here is described relatively and makes respective explanations.

The hydraulic control system that the utility model provides comprises main valve a and oil return control valve b. main valve a comprises pressure oil oil-in, oil discharge outlet T and for the first working chamber fuel feeding of the first power element and the first working oil path 433 of oil return be the 2nd working chamber fuel feeding of the first power element and the 2nd working oil path 435 of oil return. selectively control in the first working oil path 433 and the 2nd working oil path 435 one of main valve a is connected and another is connected with oil discharge outlet T with pressure oil oil-in. hydraulic control system also comprises the oil return control valve b for controlling the 2nd working chamber oil return, oil return control valve b comprises back pressure regulating valve 10, back pressure regulating valve 10 has throttling set, first oil mouth 1001 and the 2nd oil mouth 1002, first oil mouth 1001 of back pressure regulating valve 10 is connected with the 2nd working oil path 435, by connecting, working oil path 434 is connected 2nd oil mouth 1002 of back pressure regulating valve 10 with the 2nd working chamber, back pressure regulating valve 10 has the first working position, its the first oil mouth 1001 of the first working position at back pressure regulating valve 10 is connected by throttling set with the 2nd oil mouth 1002.

Owing to introducing back pressure regulating valve 10 in hydraulic control system, back pressure regulating valve 10 has the throttling set of the oil return back pressure of the 2nd working chamber for controlling the first power element, the oil return back pressure of the 2nd working chamber of the first power element can be increased when needed, it is possible to promote the pressure oil regeneration of the 2nd working chamber.

When the bucket rod oil cylinder that the first power element is excavator, it is possible to increase bucket rod oil cylinder loculus oil return back pressure, promote bucket rod oil cylinder loculus pressure oil regeneration, it is to increase excavator power utilization rate, reduce oil consumption. Excavator is applied this hydraulic control system, then can improve excavator power utilization rate, reduce oil consumption.

In addition, oil return control valve b also comprises fast unloading valve 12, and fast unloading valve 12 can be such as 2/2-way magnetic valve. Fast unloading valve 12 has the first oil mouth 1203 and the 2nd oil mouth 1204, working oil path 434 connects first oil mouth 1203 of fast unloading valve 12 with being connected, 2nd oil mouth 1204 of fast unloading valve 12 is connected with oil discharge outlet T, and this fast unloading valve 12 can control its first oil mouth 1203 and the break-make of the 2nd oil mouth 1204.

First power element can be the bucket rod oil cylinder of excavator, and the first working oil path 433 is connected with the big chamber of bucket rod oil cylinder, connects working oil path 434 and is connected with the loculus of bucket rod oil cylinder. And main valve a can comprise the first bucket bar control valve 1 and the 2nd bucket bar control valve 11, pressure oil oil-in comprises the first pressure oil oil inlet P 1 and the 2nd pressure oil oil inlet P 2, first bucket bar control valve 1 selectively controls the first working oil path 433 and is connected and another is connected with oil discharge outlet T with the first pressure oil oil inlet P 1 with in the 2nd working oil path 435, and the 2nd bucket bar control valve 11 selectively controls the first working oil path 433 and is connected and another is connected with oil discharge outlet T with the 2nd pressure oil oil inlet P 2 with in the 2nd working oil path 435.

More preferably, the loculus of bucket rod oil cylinder is only by oil return control valve b oil return. It is also preferred that first bucket bar control valve 1 and the first pressure oil oil-in between oil circuit on solid damper hole is not set.

Main valve a can also comprise for the first working chamber fuel feeding of the 2nd power element and the 3rd working oil path 408 of oil return with for the 2nd working chamber fuel feeding of the 2nd power element and the 4th working oil path 409 of oil return, and main valve a selectively controls the 3rd working oil path 408 and is connected and another is connected with oil discharge outlet T with pressure oil oil-in with in the 4th working oil path 409. More preferably, 2nd power element is the swing arm oil cylinder of excavator, main valve a also comprises the first swing arm control valve 5 and the 2nd swing arm control valve 7, first swing arm control valve 5 selectively controls the 3rd working oil path 408 and is connected and another is connected with oil discharge outlet T with the first pressure oil oil inlet P 1 with in the 4th working oil path 409, and the 2nd swing arm control valve 5 is for controlling the 3rd working oil path 408 and the break-make of the 2nd pressure oil oil-in.

Below with reference to Fig. 2 to Fig. 4, the hydraulic control system of the utility model specific embodiment is illustrated in greater detail. In the following description, the hydraulic control system of this embodiment is the bucket bar of control excavator and the hydraulic control system of swing arm. The rod oil cylinder that struggles against in the present embodiment is first working oil path of main valve a and the 2nd working oil path is the first power element of its fuel feeding and oil return, and swing arm oil cylinder is the 3rd working oil path of main valve a and the 4th working oil path is the 2nd power element of its fuel feeding and oil return. Therefore, the present embodiment additionally provides a kind of excavator comprising the hydraulic control system wherein described.

Certainly, hydraulic control system of the present utility model can also be other hydraulic control system needing power element to regenerate.

As shown in Figures 2 to 4, the hydraulic control system of the present embodiment comprises main valve a and oil return control valve b.

Main valve a comprises the first bucket bar control valve the 1, the 2nd bucket bar control valve 11, first swing arm control valve 5, the 2nd swing arm control valve 7, first check valve 2, the 2nd check valve 3, the 3rd check valve 6, the 4th check valve 8 and the 5th check valve 9.

As shown in Figure 2, main valve a also comprises the first pressure oil oil inlet P 1, the 2nd pressure oil oil inlet P 2, oil discharge outlet T and for for the first working oil path 433 of the struggle against big chamber fuel feeding of rod oil cylinder and oil return with for being the loculus fuel feeding of bucket rod oil cylinder and the 2nd working oil path 435 of oil return and other oil circuit.

Oil return control valve b comprises back pressure regulating valve 10 and fast unloading valve 12.

In the present embodiment, back pressure regulating valve 10 is a Hydraulic guide control formula 2/2-way proportional reversing valve, and bucket bar adduction guide's pressure is its control pressure, and its throttling function can regulate continuously.

As shown in Figure 2, back pressure regulating valve 10 has the first oil mouth 1001 and the 2nd oil mouth 1002, first oil mouth 1001 of back pressure regulating valve 10 is connected with the 2nd working oil path 435, working oil path 434 connects 2nd oil mouth 1002 of back pressure regulating valve 10 with being connected, and connects working oil path 434 and is connected with the loculus of bucket rod oil cylinder. Back pressure regulating valve 10 has the first working position and the 2nd working position, its the first oil mouth 1001 of the first working position at back pressure regulating valve 10 is connected with the 2nd oil mouth 1002 passing ratio throttling mouth 1008, and its first oil mouth 1001 of the 2nd working position at back pressure regulating valve 10 is directly connected with the 2nd oil mouth 1002. In the present embodiment, the natural working position working order of back pressure regulating valve 10 is for often to open, and namely nature working position is the 2nd working position, is also the lower working position in Fig. 2.

Switch between its first working position and the 2nd working position to control back pressure regulating valve 10, back pressure regulating valve 10 comprise control its first working position and the 2nd working position switching the first control end and the 2nd control end, wherein, first control end comprises pilot control opening 1006, and the 2nd control end comprises the first spring 1005.

The principle of work of back pressure regulating valve 10 is: bucket bar adduction guide's pressure oil enters the pilot control opening 1006 of back pressure regulating valve 10 from oil mouth PAa3 through oil circuit 439, makes back pressure regulating valve 10 be operated in working position, now ratio throttling mouth 1008 throttling actions.

The fast unloading valve 12 of oil return control valve b has the first oil mouth 1203 and the 2nd oil mouth 1204, working oil path 434 connects first oil mouth 1203 of fast unloading valve 12 with being connected, 2nd oil mouth 1204 of fast unloading valve 12 is connected with oil discharge outlet T, and fast unloading valve 12 can control its first oil mouth 1203 and the break-make of the 2nd oil mouth 1204. Specifically, fast unloading valve 12 is 2/2-way magnetic valve. Fast unloading valve 12 has the first working position (the left position shown in Fig. 2) and the 2nd working position (the right position shown in Fig. 2), its first oil mouth 1203 of the first working position and the 2nd oil mouth 1204 at fast unloading valve 12 disconnect, and its first oil mouth 1203 of the 2nd working position at fast unloading valve 12 is connected with the 2nd oil mouth 1204.

And, in the present embodiment, fast unloading valve 12 ratio can control valve port opening when its first oil mouth 1203 is connected with the 2nd oil mouth 1204.

Concrete mode of connection between each valve in main valve a, the oil return control valve b of the hydraulic control system of the present embodiment, oil mouth or oil circuit is described below in conjunction with Fig. 2.

As shown in Figure 2, the first pressure oil oil inlet P 1 is connected through the oil-in of oil circuit 417 with the 2nd check valve 3, and the oil outlet of the 2nd check valve 3 is connected through the oily mouth 108 of oil circuit 403 with the first bucket bar control valve 1. First pressure oil oil inlet P 1 is connected through the oily mouth 507 of oil circuit 416 with the first swing arm control valve 5. First pressure oil oil inlet P 1 is connected through the oil-in of oil circuit 415 with the 3rd check valve 6, and the 3rd check valve 6 oil outlet is connected through the oily mouth 508 of oil circuit 414 with the first swing arm control valve 5.

The rising control mouth 505 of the first swing arm control valve 5 is connected with oil mouth PAb through oil circuit 412. The decline control mouth 510 of the first swing arm control valve 5 is connected with oil mouth PBb through oil circuit 411. The working hole 502 of the first swing arm control valve 5 is connected with oil mouth Ab through oil circuit 410 and the first working oil path 408. Oil mouth Ab is connected the big chamber of swing arm oil cylinder. The working hole 501 of the first swing arm control valve 5 is connected with oil mouth Bb through the 4th working oil path 409. Oil mouth Bb is connected the loculus of swing arm oil cylinder. The oily mouth 503 of the first swing arm control valve 5 is connected through the oily mouth 107 of oil circuit 404 with the first bucket bar control valve 1. The oily mouth 504 of the first swing arm control valve 5 is connected through the oily mouth 106 of oil circuit 405 with the first bucket bar control valve 1. The oily mouth 509 of the first swing arm control valve 5 is connected with oil discharge outlet T through oil circuit 413.

The oil-in of the first check valve 2 is connected through the oily mouth 107 of oil circuit 404 with the first bucket bar control valve 1, and the oil outlet of the first check valve 2 is connected through the oil outlet of oil circuit 407 with the 2nd check valve 3. The outer pendulum control mouth 105 of the first bucket bar control valve 1 is connected with oil mouth PBa2 through oil circuit 402. The adduction control mouth 110 of the first bucket bar control valve 1 is connected with oil mouth PAa2 through oil circuit 401. The working hole 101 of the first bucket bar control valve 1 is connected with oil mouth Aa through the first working oil path 433. Oil mouth Aa is connected the big chamber of bucket rod oil cylinder. The oily mouth 109 of the first bucket bar control valve 1 is connected with oil discharge outlet T through oil circuit 406 and oil circuit 418.

The working hole 102 of the first bucket bar control valve 1 is connected with the first oil mouth 1001 of back pressure regulating valve 10 through the 2nd working oil path 435. Through connecting, working oil path 434 is connected 2nd oil mouth 1002 of back pressure regulating valve 10 with oil mouth Ba. Oil mouth Ba is connected the loculus of bucket rod oil cylinder. The pilot control opening 1006 of back pressure regulating valve 10 is connected with oil mouth PAa3 through oil circuit 439. During the logical oil of the pilot control opening 1006 of back pressure control valve, it is possible to control back pressure regulating valve 10 is in the upper working position shown in the first working position and Fig. 2, and passing ratio throttling mouth 1008 between the first oil mouth 1001 and the 2nd oil mouth 1002 is connected. Lower working position shown in 2nd working position of back pressure regulating valve 10 and Fig. 3 is then controlled by the first spring 1005. When back pressure regulating valve 10 is in the 2nd working position, the first oil mouth 1001 of back pressure regulating valve 10 is directly connected with the 2nd oil mouth 1002. Back pressure regulating valve 10 is in the first working position or the 2nd working position, and its first oil mouth 1001 and the 2nd oil mouth 1002 all can be two-way through-flow.

Control characteristic between guide's pressure of back pressure regulating valve 10 and return spring, i.e. guide's pressure control characteristic, it is possible to set according to different excavator types, add the versatility of back pressure regulating valve 10. The return spring of back pressure regulating valve 10 can carry out Secondary Control, it is possible to regulating spring pre compressed magnitude sets a pressure regulation power of load balancing as required.

2nd pressure oil oil inlet P 2 is connected through the oily mouth 706 of oil circuit 422 with the 2nd swing arm control valve 7. 2nd pressure oil oil inlet P 2 is connected with oil mouth 705 through oil circuit 420. 2nd pressure oil oil inlet P 2 is connected with the 5th check valve 9 oil-in through oil circuit 419. 5th check valve 9 oil outlet is connected with oil mouth 1109 through oil circuit 428. The oily mouth 707 of the 2nd swing arm control valve 7 is connected with oil mouth 506 through oil circuit 421. The pilot control opening 704 of the 2nd swing arm control valve 7 is connected with oil mouth PAb2 through oil circuit 423. The oily mouth 703 of the 2nd swing arm control valve 7 is connected through the oil-in of oil circuit 424 with the 4th check valve 8, and the oil outlet of the 4th check valve 8 is connected with oil mouth Ab through the first working oil path 408. The oily mouth 702 of the 2nd swing arm control valve 7 is connected through the oily mouth 1110 of oil circuit 426 with the 2nd bucket bar control valve 11. The oily mouth 701 of the 2nd swing arm control valve 7 is connected with oil mouth 1111 through oil circuit 425.

The outer pendulum pilot control opening 1113 of the 2nd bucket bar control valve 11 is connected with oil mouth PBa through oil circuit 429. The adduction pilot control opening 1105 of the 2nd bucket bar control valve 11 is connected with oil mouth PAa through oil circuit 430. The oily mouth 1104 of the 2nd bucket bar control valve 11 is connected with oil mouth Aa through oil circuit 437 and 433. The oily mouth 1107 of the 2nd bucket bar control valve 11 is connected with oil discharge outlet T through oil circuit 427.

The oily mouth 1103 of the 2nd bucket bar control valve 11 is connected with the first oil mouth 1203 of fast unloading valve 12 with being connected after working oil path 434 connects through oil circuit 436 again. 2nd oil mouth 1204 of fast unloading valve 12 connects through oil circuit 438 oil discharge outlet T. Namely fast unloading valve 12 be serially connected with back pressure regulating valve 10 the 2nd oil mouth 1002 to be connected bucket rod oil cylinder loculus oil mouth Ba between connection working oil path 434 a bypass oil circuit on. In the present embodiment, fast unloading valve 12 is automatically controlled 2/2-way proportional reversing valve, and its first oil mouth 1203 is oil-in, is connected the loculus of bucket rod oil cylinder, and the 2nd oil mouth 1204 is oil outlet, is directly connected oil return road and the oil discharge outlet T of main valve a. The natural working position working order of fast unloading valve 12 is normal closing.

As shown in Figure 2, in the present embodiment, hydraulic control system also comprises the first pressure transmitter 14 and the 2nd pressure transmitter 13. Wherein the first pressure transmitter 14 is for measuring the first pressure of the first working oil path 433, and the first pressure transmitter 14 is arranged on oil mouth Aa place, and in the present embodiment, namely the first pressure struggle against the pressure P Aa in the big chamber of rod oil cylinder. 2nd pressure transmitter 13 connects the 2nd pressure of working oil path 434 for measuring, and the 2nd pressure transmitter 13 is arranged on oil mouth Ba place. In the present embodiment, namely the 2nd pressure struggle against the pressure P Ba of rod oil cylinder loculus.

In the present embodiment, fast unloading valve 12 is according to the break-make of the first pressure and its first oil mouth 1203 of the 2nd pressure-controlling and the 2nd oil mouth 1204.

Specifically, fast unloading valve 12 has the first control end and the 2nd control end. First control end of fast unloading valve 12 is provided with the 2nd spring 1202. 2nd control end of fast unloading valve 12 is provided with solenoid 1201, according to solenoid 1201 whether be energized control fast unloading valve 12 carry out disconnecting or opening operation. As shown in Figure 2, when fast unloading valve 12 is in left working position, its first oil mouth 1203 and the 2nd oil mouth 1204 disconnect, fast unloading valve 12 is closed, and when fast unloading valve 12 is in right working position, its first oil mouth 1203 is connected with the 2nd oil mouth 1204, and fast unloading valve 12 is opened. Can according to the opening degree of the strong and weak control fast unloading valve 12 to the energy that solenoid 1201 applies when fast unloading valve 12 is opened.

Preferably, as shown in Figure 3 and Figure 4, hydraulic control system also comprises control device, first pressure transmitter 14, the solenoid 1201 of the 2nd pressure transmitter 13 and fast unloading valve 12 is connected with control device respectively, control device is greater than the first pressure control solenoid 1201 action at the 2nd pressure makes the first oil mouth 1203 of fast unloading valve 12 and the 2nd oil mouth 1204 disconnect, fast unloading valve 12 is closed, control device is less than at the 2nd pressure or equals the first pressure control solenoid 1201 action makes the first oil mouth 1203 of fast unloading valve 12 be connected with the 2nd oil mouth 1204, fast unloading valve 12 is opened.

In the present embodiment, control device is controller for excavators, i.e. excavator ECU. The control signal of fast unloading valve 12 comes from excavator ECU.

The control principle of the fast unloading valve 12 of the present embodiment is: the first pressure transmitter 14 detects the first pressure in real time and namely struggles against the pressure P Aa in the big chamber of rod oil cylinder, and is transferred to excavator ECU; Pressure transmitter 13 detects the 2nd pressure in real time and namely struggles against the pressure P Ba of rod oil cylinder loculus, and is transferred to excavator ECU. Pressure P Ba and pressure P Aa size are carried out Logic judgment by excavator ECU, send corresponding pwm signal according to judged result to solenoid 1201, thus control the unlatching of fast unloading valve 12 and close. Concrete control program is as follows:

If 1 PBa > PAa, controller ECU not output pwm signal, solenoid 1201 does not work, and fast unloading valve 12 is in left working position under the effect of spring 1202, and fast unloading valve 12 is closed;

If 2 PBa��PAa, controller ECU output pwm signal, solenoid 1201 works, and fast unloading valve 12 is in right working position under the effect of electromagnetic force, and fast unloading valve 12 is opened.

The aperture of fast unloading valve 12 is jointly controlled by the big cavity pressure of the rod oil cylinder that struggles against and the bucket little cavity pressure of rod oil cylinder so that it is can adapt to different operating modes; And fast unloading valve 12 aperture ratio changes, and makes bucket bar oil return economy steady.

In the present embodiment, back pressure regulating valve 10 and fast unloading valve 12 are interrelated, and the oil return control valve b in the common bucket bar oil return loop forming excavator, becomes one with the main valve a of excavator.

PX oil mouth in Fig. 2 is a guide oil mouth, and its pressure oil is from pioneer pump; The oil circuit being connected with PX is logic control oil circuit, makes excavator straight line moving in order to control the straight travel valve of excavator.

Hereinafter the principle of work of the hydraulic control system of the present embodiment is described in detail by divided working status.

One, excavator grading operation operating mode

The compound action carried out during excavator grading operation operating mode comprises: bucket bar adduction and swing arm rise; Pendulum and swing arm decline outside bucket bar.

1, rising for execution compound action bucket bar adduction and swing arm, embodiment of the present utility model is:

Bucket bar adduction guide's pressure oil enters the adduction pilot control opening 1105 of the 2nd bucket bar control valve 11 from oil mouth PAa through oil circuit 430 respectively, enters the adduction pilot control opening 110 of the first bucket bar control valve 1 from oil mouth PAa2 through oil circuit 401, enters the pilot control opening 1006 of back pressure regulating valve 10 from oil mouth PAa3 through oil circuit 439, the 2nd bucket bar control valve 11 is made to be in left working position, first bucket bar control valve 1 is in right working position, back pressure regulating valve 10 is in the upper working position of the first working position and Fig. 2, it is achieved bucket bar adduction and ratio throttling mouth 1008 throttling actions. The upward leader that swing arm upward leader pressure oil enters the first swing arm control valve 5 from oil mouth PAb through oil circuit 412 respectively simultaneously controls mouth 505, enters the pilot control opening 704 of the 2nd swing arm control valve 7 from oil mouth PAb2 through oil circuit 423, it is achieved swing arm rises. Time receiving in bucket bar, from oil mouth Aa to bucket rod oil cylinder big chamber fuel feeding, bucket rod oil cylinder loculus pressure oil from oil mouth Ba through oil circuit 434 oil return.

As shown in Figure 2, when the 2nd bucket bar control valve 11 is in left working position, its oil mouth 1104 is connected with oil mouth 1109, and oil mouth 1103 is connected with oil mouth 1108, but oil mouth 1108 ends. Therefore, being entered the big chamber of bucket rod oil cylinder by the 2nd bucket bar control valve 11 from the pressure oil of the 2nd pressure oil oil inlet P 2, the oil extraction of the rod oil cylinder loculus that struggles against then cannot be discharged by 1108.

In the time receiving in bucket bar, due to the effect of gravity, pressure P Ba > PAa, fast unloading valve 12 does not work. As previously mentioned, bucket bar loculus pressure oil is PBa��PAa through the right working position oil return of fast unloading valve 12 to the prerequisite of oil discharge outlet T, makes fast unloading valve 12 be operated in right position. But in the time receiving in grading operation bucket bar, due to PBa PAa, fast unloading valve 12 is operated in left position, being also exactly that fast unloading valve 12 is closed, bucket rod oil cylinder loculus just can not be connected with oil discharge outlet T through fast unloading valve 12, can only pass through back pressure regulating valve 10 oil return.

When the first bucket bar control valve 1 is in right working position, its oil mouth 101 is connected and oil mouth 102 is connected with oil mouth 109 with oil mouth 108, therefore, the pressure oil of the first pressure oil oil inlet P 1 can enter the big chamber of bucket rod oil cylinder by the first bucket bar control valve 1, and the oil return of the loculus of bucket rod oil cylinder then can be discharged by back pressure regulating valve 10, oil mouth 102 and oil mouth 109. Meanwhile, back pressure regulating valve 10 is under the effect of bucket bar adduction guide's pressure, and ratio throttling mouth 1008 throttling actions, for bucket bar adduction oil return provides an oil return back pressure, indirectly increase the adduction load of bucket bar. And along with the bucket raising of bar adduction guide's pressure proportional small orifices 1008 aperture that subtracts, increase bucket bar adduction oil return back pressure gradually, thus the load deviation of balanced bucket bar and swing arm.

And as shown in Figure 2, when the 2nd bucket bar control valve 11 is in left working position, it is connected by a check valve 1120 between oil mouth 1103 with oil mouth 1104, the oil-in of this check valve 1120 is connected with oil mouth 1103, oil outlet is connected with oil mouth 1104, therefore, time receiving in grading operation bucket bar, the loculus pressure P Ba being in left working position and bucket rod oil cylinder due to the 2nd bucket bar control valve 11 is greater than big cavity pressure PAa, the oil return of bucket rod oil cylinder loculus will flow to the big chamber of bucket rod oil cylinder by oil mouth 1103, check valve 1120 and oil mouth 1104, thus realizes regeneration.

Known according to above description, in bucket bar, time receiving oil return is not by the 2nd bucket bar control valve 11 and fast unloading valve 12 oil return, but by the first bucket bar control valve 1 oil return, and under the regulating effect of back pressure regulating valve 10, increase bucket rod oil cylinder loculus oil return pressure, be more conducive to promoting regeneration.

Back pressure regulating valve 10 can regulate the adduction load pressure of bucket bar continuously by bucket bar adduction guide, and solving fixing damping 3 can not regulate continuously, it is necessary to the problem of dismounting and change, improves operation efficiency effectively, reduces debugging intensity.

Under grading operation operating mode, when bucket bar adduction and swing arm rise, by back pressure regulating valve 10 can simultaneously to first bucket bar control valve 1 and the 2nd bucket bar control valve 11 import load pressure regulate, thus when realizing grading operation swing arm and bucket bar load pressure equilibrium. In the time receiving in bucket bar, as shown in Figure 2, guide oil mouth PAa2 enters oil, and the first bucket bar control valve 1 right position work, the pressure oil of bucket rod oil cylinder loculus is through oil circuit 434, back pressure regulating valve 10, oil circuit 435 oil return. Meanwhile, guide oil mouth PAa enters oil, and the 2nd bucket bar control valve 11 left position work, the loculus pressure oil of bucket rod oil cylinder is also through oil circuit 434, back pressure regulating valve 10, oil circuit 435 oil return. Therefore, back pressure regulating valve 10 can regulate the oil return back pressure of bucket bar loculus, and then regulated the pressure in the big chamber of bucket rod oil cylinder by check valve 1120, namely controls the import load pressure of the first bucket bar control valve 1 and the 2nd bucket bar control valve 11.

2, for pendulum outside bucket bar and swing arm decline, embodiment of the present utility model is:

Put guide's pressure oil outside bucket bar to enter the outer pendulum pilot control opening 1113 of the 2nd bucket bar control valve 11 from oil mouth PBa through oil circuit 429 respectively, enter the outer pendulum pilot control opening 105 of the first bucket bar control valve 1 from oil mouth PBa2 through oil circuit 402, the 2nd bucket bar control valve 11 is made to be in right working position, first bucket bar control valve 1 is in left working position, it is achieved pendulum outside bucket bar.

The guide's pressure oil of swing arm decline simultaneously enters the decline pilot control opening 510 of the first swing arm control valve 5 from oil mouth PBb through oil circuit 411, it is achieved swing arm declines.

The problem of load imbalance is there is not when pendulum and swing arm decline outside bucket bar. Back pressure regulating valve 10 is in the 2nd working position under return spring 1005 acts on, and namely the lower working position shown in Fig. 2, does not have throttling action.

Visible, by accessing back pressure regulating valve 10 in bucket rods circuit oil circuit, both can realize bucket bar adduction, it is also possible to put outside realizing bucket bar.

Two, excavator excavates operation continuously

It is periodically repeat operation that excavator excavates continuously, and excavator excavates and mainly realizes the cutting to the earthwork, dress bucket by bucket bar adduction and scraper bowl adduction composite moving, has excavated laggard row boom arm lift, revolution entrucking. When excavating, due to the effect of earthwork resistance, there is not the unbalanced problem of load pressure in scraper bowl and bucket bar. Now, if in the hydraulic control system shown in Fig. 2, still prior art as shown in Figure 1 arranges the effect that fixing damper hole 3 ' just loses balanced load like that in the loop, and, main pump still will by fixing damper hole 3 ' to bucket bar fuel feeding, also can increase unnecessary throttling loss, increase system radiating, and reduce working efficiency. Therefore, the present embodiment in terms of existing technologies, eliminates fixing damper hole and can overcome the deficiency brought with fixing damper hole.

For continuous digging working condition, embodiment of the present utility model is: bucket bar adduction guide's pressure oil enters the adduction pilot control opening 1105 of the 2nd bucket bar control valve 11 respectively from oil mouth PAa through oil circuit 430, enter the adduction pilot control opening 110 of the first bucket bar control valve 1 through oil circuit 401 from oil mouth PAa2, from oil mouth PAa3 through oil circuit 439 enter back pressure regulating valve 10 pilot control opening 1006, the 2nd bucket bar control valve 11 is made to be in left working position, first bucket bar control valve 1 is in right working position, back pressure regulating valve 10 is in working position, realize bucket bar adduction and ratio throttling mouth 1008 throttling actions.

When carrying out bucket bar adduction and excavate, due to the dual function of earthwork resistance and back pressure regulating valve 10, the pressure P Aa in the bucket big chamber of rod oil cylinder is greater than the pressure P Ba of bucket rod oil cylinder loculus, and namely during PBa��PAa, now fast unloading valve 12 is under the effect of excavator ECU, commutate to right working position, bucket rod oil cylinder loculus and main valve a oil return road and oil discharge outlet T are directly connected, it is achieved back pressure off-load, oil return back pressure is down to minimum, now, back pressure regulating valve 10 can not regulate the back pressure of bucket rod oil cylinder loculus.

The hydraulic control system of the present embodiment is when controlling hydraulic excavator bucket oil return, it is possible to adapt to different operating mode, has the function of bucket bar adduction oil return back pressure quick relief when regulating bucket bar oil return back pressure continuously and realize excavating operation. Wherein, the loculus of bucket rod oil cylinder is by back pressure control valve 10 oil return or by fast unloading valve 12 oil return, thus the loculus of the rod oil cylinder that struggles against in the present embodiment is only by oil return control valve b oil return.

Describe it will be seen that the hydraulic control system of the above embodiment of the utility model is particularly useful for the bucket bar to excavator controls according to above. This hydraulic control system solves the inconsistent problem of excavator boom regeneration, bucket bar oil return back pressure quick relief and bucket bar, movable arm loop load pressure. Further, this hydraulic control system has been simplified main valve structure, has been increased the versatility of Hydraulic Elements, it is possible to adapts to various working, have continuous regulatory function to ensure the Harmony of excavator action and to reduce excavator oil consumption, it is achieved be energy-efficient. The advantage that this hydraulic control system and excavator have is as follows:

1, by introducing back pressure regulating valve 10, in excavator working process, according to different operating mode, the back pressure in bucket bar oil return loop is regulated, bucket rod oil cylinder loculus oil return back pressure can be increased when needing, promote bucket rod oil cylinder loculus pressure oil regeneration, it is to increase excavator power utilization rate, reduce unnecessary power loss, reduce oil consumption.

2, by introducing back pressure regulating valve 10, it is possible to bucket bar and swing arm load pressure inconsistent problem when solving excavator grading operation operating mode, ensure that the Harmony of excavator action.

3, by back pressure regulating valve 10 being changed the first spring 1005 of different elasticity rigidity, the relation between multiple guide's pressure and back pressure regulating valve 10 throttling action can be obtained, the i.e. control characteristic of back pressure regulating valve 10, it is to increase the versatility of back pressure regulating valve 10, and change convenient.

4, by introducing back pressure regulating valve 10, it is possible to regulating spring pre compressed magnitude sets rising of back pressure regulating valve 10 and adjusts point, convenience and the handiness of oil return control is added.

5, by introducing back pressure regulating valve 10, it is possible to do not arrange fixing damper hole, avoid fixing damper hole to the throttling action of oil circuit, reduce unnecessary power loss, it is to increase hydraulic work system efficiency also reduces complete machine oil consumption.

6, by introducing fast unloading valve 12, it is possible to reduce oil return back pressure when excavator excavates, it is to increase excavator digging force, reduce watt consumption.

7, by introducing fast unloading valve 12, when excavator excavates operation, it is possible to control bucket rod oil cylinder loculus directly connects fuel tank, increase bucket bar adduction oil return speed, make bucket rod oil cylinder loculus oil return pressure quick relief, reduce bucket bar oil return back pressure, it is to increase the working efficiency of excavator. 8, by fast unloading valve 12 is adopted automatically controlled mode, it is possible to according to the size of the big cavity pressure of bucket rod cylinder of excavator and little cavity pressure, bucket bar oil return back pressure is regulated in real time.

Finally should be noted that: above embodiment is only in order to illustrate that the technical solution of the utility model is not intended to limit; Although being described in detail by the utility model with reference to better embodiment, those of ordinary skill in the field are it is understood that still can modify to embodiment of the present utility model or part technology feature carries out equivalent replacement; And do not depart from the spirit of technical solutions of the utility model, in the middle of its technical scheme scope that all should be encompassed in the utility model request protection.

Claims (18)

1. a hydraulic control system, comprise main valve (a), described main valve (a) comprises pressure oil oil-in, oil discharge outlet (T) and for for the first working chamber fuel feeding of the first power element and first working oil path (433) of oil return be the 2nd working chamber fuel feeding of described first power element and the 2nd working oil path (435) of oil return, selectively control in described first working oil path (433) and described 2nd working oil path (435) one is connected and another is connected with described oil discharge outlet (T) described main valve (a) with described pressure oil oil-in, it is characterized in that, described hydraulic control system also comprises oil return control valve (b) for controlling described 2nd working chamber oil return, described oil return control valve (b) comprises back pressure regulating valve (10), described back pressure regulating valve (10) has throttling set, first oil mouth (1001) and the 2nd oil mouth (1002), first oil mouth (1001) of described back pressure regulating valve (10) is connected with described 2nd working oil path (435), by connecting, working oil path (434) is connected 2nd oil mouth (1002) of described back pressure regulating valve (10) with described 2nd working chamber, described back pressure regulating valve (10) has the first working position, its first oil mouth (1001) of the first working position at described back pressure regulating valve (10) is connected by described throttling set with the 2nd oil mouth (1002).

2. hydraulic control system according to claim 1, it is characterised in that, the aperture of described throttling set can regulate continuously.

3. hydraulic control system according to claim 1, it is characterised in that, described throttling set is ratio throttling mouth (1008).

4. hydraulic control system according to claim 1, it is characterized in that, described back pressure regulating valve (10) also has the 2nd working position, and its first oil mouth (1001) of the 2nd working position at described back pressure regulating valve (10) is directly connected with the 2nd oil mouth (1002).

5. hydraulic control system according to claim 4, it is characterized in that, described back pressure regulating valve (10) comprise control its first working position and the 2nd working position switching the first control end and the 2nd control end, wherein, first control end of described back pressure regulating valve (10) comprises pilot control opening (1006), and described 2nd control end of described back pressure regulating valve (10) comprises the first spring (1005).

6. hydraulic control system according to claim 1, it is characterized in that, described oil return control valve (b) also comprises fast unloading valve (12), described fast unloading valve (12) has the first oil mouth (1203) and the 2nd oil mouth (1204), first oil mouth (1203) of described fast unloading valve (12) connects with the described working oil path (434) that is connected, 2nd oil mouth (1204) of described fast unloading valve (12) is connected with described oil discharge outlet (T), described fast unloading valve (12) can control the break-make of its first oil mouth (1203) with the 2nd oil mouth (1204).

7. hydraulic control system according to claim 6, it is characterised in that, described fast unloading valve (12) ratio can control the aperture of valve port when its first oil mouth (1203) is connected with the 2nd oil mouth (1204).

8. hydraulic control system according to claim 6, it is characterized in that, described hydraulic control system also comprises the first pressure transmitter (14) and the 2nd pressure transmitter (13), described first pressure transmitter (14) is for measuring the first pressure of described first working oil path (433), described 2nd pressure transmitter is for measuring the 2nd pressure of described connection working oil path (434), described fast unloading valve (12) is according to the break-make of described first pressure and its first oil mouth (1203) of described 2nd pressure-controlling and the 2nd oil mouth (1204).

9. hydraulic control system according to claim 8, it is characterized in that, a control end of described fast unloading valve (12) comprises solenoid (1201), described hydraulic control system also comprises control device, described first pressure transmitter (14), the solenoid (1201) of described 2nd pressure transmitter (13) and described fast unloading valve (12) is connected with described control device respectively, described control device is greater than solenoid (1201) described in described first pressure control at described 2nd pressure makes the first oil mouth (1203) of described fast unloading valve (12) disconnect with the 2nd oil mouth (1204), described control device is less than at described 2nd pressure or equals solenoid (1201) described in described first pressure control makes the first oil mouth (1203) of described fast unloading valve (12) be connected with the 2nd oil mouth (1204).

10. hydraulic control system according to claim 6, it is characterised in that, the 2nd working chamber of described first power element is by means of only described oil return control valve (b) oil return.

11. hydraulic control systems according to any one of claim 1 to 10, it is characterized in that, described first power element is the bucket rod oil cylinder of excavator, and described first working chamber is the big chamber of described bucket rod oil cylinder, and described 2nd working chamber is the loculus of described bucket rod oil cylinder.

12. hydraulic control systems according to claim 11, it is characterized in that, described main valve (a) comprises the first bucket bar control valve (1) and the 2nd bucket bar control valve (11), described pressure oil oil-in comprises the first pressure oil oil-in (P1) and the 2nd pressure oil oil-in (P2), described first bucket bar control valve (1) selectively controls described first working oil path (433) and is connected and another is connected with described oil discharge outlet (T) with described first pressure oil oil-in (P1) with in described 2nd working oil path (435), described 2nd bucket bar control valve (11) selectively controls in described first working oil path (433) and described 2nd working oil path (435) and described 2nd pressure oil oil-in (P2), it is connected and another is connected with described oil discharge outlet (T).

13. hydraulic control system according to claim 12, it is characterised in that, the oil circuit between described first bucket bar control valve (1) and described first pressure oil oil-in (P1) does not arrange solid damper hole.

14. hydraulic control systems according to claim 12, it is characterized in that, enter oil in the big chamber of described bucket rod oil cylinder and during the loculus oil return of the rod oil cylinder that struggles against, disconnecting and oily mouth (1104) connection for being connected with the big chamber of described bucket rod oil cylinder of the bar control valve (11) that struggled against with the described 2nd by check valve (1120) with described oil discharge outlet for the oily mouth (1103) being connected with the loculus of described bucket rod oil cylinder of described 2nd bucket bar control valve (11).

15. hydraulic control systems according to any one of claim 1 to 10, it is characterized in that, described main valve (a) also comprises for for the first working chamber fuel feeding of the 2nd power element and the 3rd working oil path (408) of oil return with for being the 2nd working chamber fuel feeding of described 2nd power element and the 4th working oil path (409) of oil return, described main valve (a) selectively controls described 3rd working oil path (408) and is connected and another is connected with described oil discharge outlet (T) with described pressure oil oil-in with in described 4th working oil path (409).

16. hydraulic control systems according to claim 12, it is characterized in that, described main valve (a) also comprises for the first working chamber fuel feeding of the 2nd power element and the 3rd working oil path (408) of oil return with for being the 2nd working chamber fuel feeding of described 2nd power element and the 4th working oil path (409) of oil return, described 2nd power element is the swing arm oil cylinder of described excavator, described main valve (a) also comprises the first swing arm control valve (5) and the 2nd swing arm control valve (7), described first swing arm control valve (5) selectively controls described 3rd working oil path (408) and is connected and another is connected with described oil discharge outlet (T) with described first pressure oil oil-in (P1) with in described 4th working oil path (409), described 2nd swing arm control valve (5) is for controlling described 3rd working oil path (408) and the break-make of described 2nd pressure oil oil-in (P2).

17. hydraulic control systems according to any one of claim 1 to 10, it is characterised in that, described main valve (a) and described oil return control valve (b) become one.

18. 1 kinds of excavators, it is characterised in that, comprise the hydraulic control system according to any one of claim 1 to 17.