CN219672959U - Hydraulic system of working device of excavator and excavator - Google Patents

Abstract

The utility model belongs to the technical field of engineering machinery, and discloses a hydraulic system of an excavator working device and an excavator. According to the hydraulic system of the excavator working device, hydraulic oil in the oil tank is conveyed to the rodless cavity of the bucket rod oil cylinder through the oil distribution assembly to push the piston rod of the bucket rod oil cylinder to extend outwards, the oil distribution assembly can conduct oil pipe on-off control to convey the hydraulic oil output through the rod cavity of the bucket rod oil cylinder into the rodless cavity of the bucket rod oil cylinder again, so that the extending speed of the piston rod is increased, and further the working efficiency of the excavator is improved.

Description

Hydraulic system of working device of excavator and excavator

Technical Field

The utility model relates to the technical field of engineering machinery, in particular to a hydraulic system of an excavator working device and an excavator.

Background

In the construction of large underground shops, subways and underground parking lots, an excavator is one of main construction equipment, and mainly completes hard ground crushing and earthwork excavation. At present, small and medium-sized excavators are commonly used for construction work in some scenes with smaller construction space. The small and medium-sized excavator is small in self structural size, small in engine power and small in auxiliary bucket capacity, and the lifting speed of the bucket rod cannot be adaptively adjusted according to the operation requirement of actual construction, so that the working efficiency of the small and medium-sized excavator is limited, and the small and medium-sized excavator cannot meet the requirement in some occasions with short construction period.

Disclosure of Invention

The utility model aims to provide a hydraulic system of an excavator working device and an excavator, which can improve the lifting speed of a bucket rod according to the requirement of a use scene and improve the working efficiency.

To achieve the purpose, the utility model adopts the following technical scheme:

the hydraulic system of the working device of the excavator comprises an oil tank, an oil pump, an oil delivery reversing valve and a bucket rod oil cylinder, wherein the oil tank is communicated with an oil inlet of the oil pump, an oil outlet of the oil pump is communicated with an oil inlet of the oil delivery reversing valve, the hydraulic system of the working device of the excavator also comprises an oil distribution assembly, one working oil port of the oil delivery reversing valve is communicated with a rodless cavity of the bucket rod oil cylinder through the oil distribution assembly, and the other working oil port of the oil delivery reversing valve is communicated with a rod cavity of the bucket rod oil cylinder through the oil distribution assembly;

hydraulic oil in the oil tank can be sequentially conveyed to the rodless cavity of the bucket rod oil cylinder through the oil pump, the oil conveying reversing valve and the oil distribution assembly to push the piston rod of the bucket rod oil cylinder to extend outwards, and the oil distribution assembly can conduct oil pipe on-off control to convey the hydraulic oil output through the rod cavity of the bucket rod oil cylinder into the rodless cavity of the bucket rod oil cylinder again to increase the extending speed of the piston rod.

Optionally, the oil distributing assembly comprises a first cartridge valve, a second cartridge valve, a differential reversing valve and a shuttle valve; wherein,,

the two working oil ports of the oil transportation reversing valve are respectively communicated with an a1 oil port of the first cartridge valve and a b1 oil port of the second cartridge valve through a first oil pipe and a second oil pipe, an a2 oil port of the first cartridge valve is communicated with a b2 oil port of the second cartridge valve through a third oil pipe, a rod cavity of the bucket rod oil cylinder is communicated with the third oil pipe through a fourth oil pipe, a rodless cavity of the bucket rod oil cylinder is communicated with the first oil pipe through a fifth oil pipe, the fifth oil pipe and the second oil pipe are respectively communicated with a c1 oil inlet and a c2 oil inlet of the shuttle valve, an oil outlet of the shuttle valve is communicated with an oil inlet of the differential reversing valve, and two working oil ports of the differential reversing valve are respectively communicated with an a3 oil port of the first cartridge valve and a3 oil port of the second cartridge valve.

Optionally, the differential reversing valve is set as a two-position four-way electromagnetic reversing valve; the oil delivery reversing valve is arranged as a two-position four-way electromagnetic reversing valve.

An excavator comprising the excavator work device hydraulic system of any one of the preceding claims, further comprising:

a body;

the arm support assembly comprises a movable arm and an arm support, wherein the first end of the movable arm is hinged to the machine body, the second end of the movable arm is hinged to the first end of the arm support, an auxiliary tool is hinged to the second end of the arm support, the first cartridge valve, the second cartridge valve, the differential reversing valve and the shuttle valve are all arranged on the movable arm, a cylinder body and a piston rod of the arm cylinder are hinged to the movable arm and the arm respectively, and the arm cylinder is arranged below the movable arm.

Optionally, the movable arm includes first straight section and second straight section, first straight section with connect through circular arc bending section between the second straight section, first straight section with the organism articulates mutually, the second straight section with the dipper is articulated mutually, the opposite both sides of circular arc bending section are provided with first reinforcing plate.

Optionally, second reinforcing plates are arranged on two opposite sides of the bucket rod.

Optionally, the hydraulic lifting device further comprises a movable arm oil cylinder, wherein a cylinder body and a piston rod of the movable arm oil cylinder are hinged with the machine body and the movable arm respectively, and the movable arm oil cylinder is arranged below the movable arm.

Optionally, the device further comprises an auxiliary oil cylinder, wherein a cylinder body and a piston rod of the auxiliary oil cylinder are hinged with the bucket rod and the auxiliary tool respectively.

Optionally, a cab is further arranged on the machine body, and a bottom plate of the cab sinks into the frame of the machine body.

Optionally, the movable arm is further provided with a plurality of pedals, and the pedals are arranged at intervals along the length direction of the movable arm.

The beneficial effects are that:

according to the hydraulic system of the working device of the excavator, when the bucket rod of the excavator is normally lifted, hydraulic oil in the oil tank can be sequentially conveyed to the rodless cavity of the bucket rod oil cylinder through the oil pump, the oil conveying reversing valve and the oil liquid distribution assembly to push the piston rod of the bucket rod oil cylinder to extend outwards at a normal speed; when the excavator needs to lift the working speed of the bucket rod, the oil distribution assembly can conduct oil pipe on-off control to convey hydraulic oil output through the rod cavity of the bucket rod oil cylinder into the rod-free cavity of the bucket rod oil cylinder again, so that the speed of extending the piston rod is increased, the lifting speed of the bucket rod of the excavator is effectively improved, and the working efficiency is further improved.

Drawings

FIG. 1 is a schematic diagram of a hydraulic system of an excavator work apparatus provided by the present utility model;

FIG. 2 is a schematic view of an excavator provided by the present utility model;

FIG. 3 is a schematic view of a cab portion provided by the present utility model;

FIG. 4 is a schematic view of the structure of the boom provided by the present utility model;

FIG. 5 is a schematic view of the structure of the stick provided by the present utility model;

fig. 6 is a schematic structural diagram of the accessory provided by the utility model.

In the figure:

110. an oil tank; 120. an oil pump; 130. an oil delivery reversing valve; 140. a bucket rod oil cylinder; 150. a first cartridge valve; 160. a second cartridge valve; 170. a differential reversing valve; 180. a shuttle valve; 191. a first oil pipe; 192. a second oil pipe; 193. a third oil pipe; 194. a fourth oil pipe; 195. a fifth oil pipe;

200. a body; 210. a cab; 211. a bottom plate;

310. a movable arm; 311. a first straight section; 3111. a first hinge hole; 312. a second straight section; 3121. a second hinge hole; 3122. a fourth hinge hole; 313. a circular arc bending section; 3131. a third hinge hole; 314. a first reinforcing plate; 320. a bucket rod; 3201. a fifth hinge hole; 3202. a sixth hinge hole; 3203. a seventh hinge hole; 3204. an eighth hinge hole; 3205. a ninth hinge hole; 321. a second reinforcing plate; 330. an auxiliary tool; 331. a tenth hinge hole; 332. an eleventh hinge hole; 340. a foot pedal;

400. a boom cylinder;

500. an auxiliary oil cylinder; 510. a protective sleeve;

610. a first link; 620. and a second link.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present utility model are shown in the drawings.

In the description of the present utility model, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

The present embodiment provides a hydraulic system for an excavator working device, as shown with reference to fig. 1. The hydraulic system of the excavator working device comprises an oil tank 110, an oil pump 120, an oil delivery reversing valve 130, a bucket rod oil cylinder 140 and an oil distribution assembly, wherein the oil tank 110 is communicated with an oil inlet of the oil pump 120, an oil outlet of the oil pump 120 is communicated with an oil inlet of the oil delivery reversing valve 130, one working oil port of the oil delivery reversing valve 130 is communicated with a rodless cavity of the bucket rod oil cylinder 140 through the oil distribution assembly, and the other working oil port of the oil delivery reversing valve 130 is communicated with a rod cavity of the bucket rod oil cylinder 140 through the oil distribution assembly.

In this embodiment, when the boom of the excavator is normally lifted, hydraulic oil in the oil tank 110 can be sequentially delivered to the rodless cavity of the boom cylinder 140 through the oil pump 120, the oil delivery reversing valve 130 and the oil distribution assembly to push the piston rod of the boom cylinder 140 to extend outwards at a normal speed; when the excavator needs to lift the working speed of the bucket rod, the oil distribution assembly can conduct oil pipe on-off control to convey hydraulic oil output through the rod cavity of the bucket rod oil cylinder 140 into the rod-free cavity of the bucket rod oil cylinder 140 again, so that the speed of extending the piston rod is increased, the lifting speed of the bucket rod of the excavator is effectively improved, and the working efficiency is further improved.

Specifically, with continued reference to fig. 1, the oil distribution assembly includes a first cartridge valve 150, a second cartridge valve 160, a differential directional valve 170, and a shuttle valve 180, wherein two working ports of the oil delivery directional valve 130 are respectively communicated with an a1 port of the first cartridge valve 150 and a b1 port of the second cartridge valve 160 through a first oil pipe 191 and a second oil pipe 192, an a2 port of the first cartridge valve 150 is communicated with a b2 port of the second cartridge valve 160 through a third oil pipe 193, a rod cavity of the arm cylinder 140 is communicated with the third oil pipe 193 through a fourth oil pipe 194, a rod-free cavity of the arm cylinder 140 is communicated with the first oil pipe 191 through a fifth oil pipe 195 and a second oil pipe 192 are respectively communicated with a c1 oil inlet and a c2 oil inlet of the shuttle valve 180, an oil outlet of the shuttle valve 180 is communicated with an oil inlet of the differential directional valve 170, and two working ports of the differential directional valve 170 are respectively communicated with an a3 port of the first cartridge valve 150 and a3 port of the second cartridge valve 160.

In this embodiment, when the excavator bucket rod works at a normal speed, the differential reversing valve 170 does not work, and the right position thereof is the working position, that is, the oil inlet of the differential reversing valve 170 is communicated with the d1 working oil port to communicate the oil path between the oil outlet and the a3 oil port of the shuttle valve 180, at this time, hydraulic oil of the oil tank 110 is pumped into the first oil pipe 191 by the oil pump 120, a part of hydraulic oil entering the first oil pipe 191 enters the rodless cavity of the bucket rod cylinder 140 through the fifth oil pipe 195 to push the piston rod of the bucket rod cylinder 140 to extend outwards so as to control the excavator bucket rod to lift, another part of hydraulic oil flows into the shuttle valve 180 through the c1 oil port, the c2 oil inlet of the shuttle valve 180 is blocked and sequentially enters the first oil pipe 150 through the oil outlet of the shuttle valve 180, the d1 working oil port of the differential reversing valve 170, and the a3 oil port of the first cartridge valve 150, that is blocked from being communicated with the a1 oil port of the first cartridge valve 150, that is blocked from being communicated with the third oil pipe 193, that is, the hydraulic oil entering the fourth oil pipe 194 in the sequential cavity of the bucket rod cylinder 140 is blocked from being sequentially communicated with the third oil pipe 193 b through the fourth oil pipe 193, that is sequentially communicated with the third oil pipe 192 b2 oil pipe 2 b, and the hydraulic oil port is sequentially opened through the third oil pipe 192 b2 oil pipe 2 b and the third oil pipe 192.

When the excavator needs to raise the working speed of the bucket rod, the differential directional valve 170 works, the left position of the differential directional valve is converted into a working position, namely, the oil inlet of the differential directional valve 170 is communicated with the d2 working oil port, at this time, a part of hydraulic oil entering the first oil pipe 191 enters the rodless cavity of the bucket rod cylinder 140 through the fifth oil pipe 195, another part of hydraulic oil flows into the shuttle valve 180 through the c1 oil inlet, blocks the c2 oil inlet of the shuttle valve 180 and sequentially enters the second cartridge valve 160 through the oil outlet of the shuttle valve 180, the oil inlet of the differential directional valve 170, the d2 working oil port of the differential directional valve 170 and the b3 oil port of the second cartridge valve 160, so that the second cartridge valve 160 blocks the conduction between the b1 oil port and the b2 oil port, namely, the conduction between the second oil pipe 192 and the third oil pipe 193, hydraulic oil in the rod cavity of the bucket rod cylinder 140 sequentially enters the third oil pipe 193 through the fourth oil pipe 194, and because the conduction between the second oil pipe 192 and the third oil pipe 193 is blocked, the hydraulic oil flows towards the a2 oil port and enables the first cartridge valve 150 to be opened to conduct an oil path between the a2 oil port and the a1 oil port, namely, the third oil pipe 193 is conducted with the fifth oil pipe 195, at the moment, the hydraulic oil flows into the fifth oil pipe 195 sequentially through the a2 oil port and the a1 oil port, and is combined with the hydraulic oil directly entering the fifth oil pipe 195 from the first oil pipe 191 and jointly enters the rod-free cavity of the bucket rod cylinder 140, so that the piston rod of the bucket rod cylinder 140 is jointly pushed to extend outwards, the lifting speed of the excavator bucket rod is effectively improved, and the working efficiency is further improved.

In addition, when the bucket rod of the excavator is controlled to fall back, the differential directional valve 170 does not work, the right position of the differential directional valve 170 is a working position, that is, the oil inlet of the differential directional valve 170 is communicated with the d1 working oil port to communicate the oil path between the oil outlet and the a3 oil port of the shuttle valve 180, at this moment, the oil transfer directional valve 130 is switched over, so that the hydraulic oil in the oil tank 110 flows into the second oil pipe 192 after passing through the oil pump 120, a part of the hydraulic oil entering the second oil pipe 192 flows into the shuttle valve 180 through the c2 oil inlet, the c1 oil inlet of the shuttle valve 180 is blocked, and sequentially enters the first cartridge valve 150 through the oil outlet of the shuttle valve 180, the d1 working oil port of the differential directional valve 170 and the a3 oil port of the first cartridge valve 150, so as to block the conduction between the a1 oil port and the a2 oil port of the first cartridge valve 150, that is blocked, at this moment, another part of the hydraulic oil entering the second oil pipe 192 flows towards the b1 oil port and opens the oil path between the b1 oil port and the b2 oil port, and this part of the hydraulic oil flows back to the fifth oil pipe 140 through the fourth oil pipe 194 and the bucket rod 140, and thus the fifth oil pipe 140 is realized.

In this embodiment, the specific structures of the first cartridge valve 150, the second cartridge valve 160, and the shuttle valve 180 are all the prior art, and will not be described herein in detail.

In the present embodiment, the differential directional valve 170 is a two-position four-way electromagnetic directional valve, and the oil delivery directional valve 130 is a two-position four-way electromagnetic directional valve.

The embodiment also provides an excavator, which comprises the excavator working device hydraulic system. Referring to fig. 2 to 6, the excavator further includes a body 200 and a boom assembly, wherein the boom assembly includes a boom 310 and an arm 320, a first end of the boom 310 is hinged to the body 200, a second end of the boom 310 is hinged to a first end of the arm 320, an auxiliary tool 330 is hinged to a second end of the arm 320, the first cartridge valve 150, the second cartridge valve 160, the differential directional valve 170 and the shuttle valve 180 are all disposed on the boom 310, a cylinder body and a piston rod of the arm cylinder 140 are respectively hinged to the boom 310 and the arm 320, and the arm cylinder 140 is disposed below the boom 310.

In this embodiment, the excavator working device hydraulic system is applied to the excavator, so that all the beneficial effects of the excavator working device hydraulic system can be achieved, and the lifting speed of the excavator bucket rod can be effectively improved according to working conditions, so that the working efficiency is further improved.

In addition, the bucket rod cylinder 140 of the excavator provided by the embodiment is arranged below the movable arm 310, namely, a turning type operation mode is adopted, so that the height dimension of a knot component above the movable arm 310 can be further liberated, the excavator can be further adapted to the operation environment of a low-space place, the height of the excavator is reduced, and the trafficability of the excavator is improved.

Further, referring to fig. 2 and 3, a cab 210 is further disposed on the machine body 200, and a bottom plate 211 of the cab 210 is sunk into the frame of the machine body 200, that is, the cab 210 of the excavator adopts a sunk structure, so that the height of the whole machine is further reduced, and the trafficability of the whole machine is improved. In addition, the sinking structure of the cab 210 can further secure a sufficient riding space, ensuring the comfort of operation.

Further, as shown in fig. 2, the excavator further includes a boom cylinder 400 and an auxiliary cylinder 500, wherein a cylinder body and a piston rod of the boom cylinder 400 are respectively hinged with the machine body 200 and the boom 310, and a cylinder body and a piston rod of the auxiliary cylinder 500 are respectively hinged with the arm 320 and the auxiliary 330.

In this embodiment, the boom cylinder 400 is also disposed below the boom 310, so that the height of the boom 310 can be further reduced, and the overall machine trafficability can be further improved.

Specifically, referring to fig. 2 and 4, the movable arm 310 includes a first straight section 311 and a second straight section 312, the first straight section 311 and the second straight section 312 are connected by an arc bending section 313, the first straight section 311 is hinged with the machine body 200, the second straight section 312 is hinged with the arm 320, and two opposite sides of the arc bending section 313 are provided with a first reinforcing plate 314. Specifically, the first reinforcing plate 314 is welded on the movable arm 310, and the first reinforcing plate 314 can strengthen the whole strength of the movable arm 310, thereby improving the reliability. In this embodiment, the first straight section 311, the second straight section 312 and the arc bending section 313 of the movable arm 310 are all formed by welding high-strength steel plates, and the length of the second straight section 312 of the movable arm 310 is greater than the length of the first straight section 311.

Specifically, the end of the first straight section 311 is provided with a first hinge hole 3111, and the first hinge hole 3111 is adapted to hinge with the body 200 of the excavator. A second hinge hole 3121 and a fourth hinge hole 3122 are opened at an end of the second straight section 312, the second hinge hole 3121 is used to hinge with the stick 320 of the excavator, and the fourth hinge hole 3122 is used to hinge with the telescopic end of the piston rod of the boom cylinder 400. The arc bending section 313 is provided with a third hinge hole 3131, and the third hinge hole 3131 is used for being hinged with a fixed end of the cylinder body of the arm cylinder 140.

Further, a fifth hinge hole 3201, a seventh hinge hole 3203, and an eighth hinge hole 3204 are formed at an end of the arm 320 corresponding to the boom 310, wherein the fifth hinge hole 3201 is used for hinge-connecting with the second hinge hole 3121 on the boom 310, the seventh hinge hole 3203 is used for hinge-connecting with a telescopic end of a piston rod of the arm cylinder 140, and the eighth hinge hole 3204 is used for hinge-connecting with a fixed end of a cylinder body of the auxiliary cylinder 500.

Further, as shown in fig. 2 and 5, second reinforcing plates 321 are provided on opposite sides of the arm 320. The second reinforcing plate 321 is welded to the arm 320, and the second reinforcing plate 321 can further strengthen the overall strength of the arm 320, thereby improving the reliability of the arm 320.

Further, a sixth hinge hole 3202 is formed at an end of the arm 320 corresponding to the auxiliary tool 330, and a tenth hinge hole 331 for hinge-connecting with the sixth hinge hole 3202 is formed at the auxiliary tool 330.

In this embodiment, a link assembly is further disposed between the arm 320 and the auxiliary tool 330, and the link assembly includes a first link 610 and a second link 620. Specifically, a ninth hinge hole 3205 is formed at one end of the arm 320 corresponding to the auxiliary tool 330, an eleventh hinge hole 332 is formed in the auxiliary tool 330, a first end of the first link 610 is hinged to the ninth hinge hole 3205, a second end of the first link 610, a first end of the second link 620 and a telescopic end of a piston rod of the auxiliary tool cylinder 500 are hinged to one point, and a second end of the second link 620 is hinged to the eleventh hinge hole 332. Specifically, the piston rod of the auxiliary tool cylinder 500 extends out relative to the cylinder body to drive the first link 610 and the second link 620 to swing, so as to drive the auxiliary tool 330 to swing relative to the arm 320 about the hinge point connected between the sixth hinge hole 3202 and the tenth hinge hole 331, thereby realizing the hinge swing of the auxiliary tool 330.

It should be noted that the auxiliary tool at the end of the arm 320 may be a table, a fork, or other components, which are not limited herein.

Further, as shown in fig. 2, the auxiliary oil cylinder 500 is further provided with a protection sleeve 510, and the protection sleeve 510 is provided to effectively protect the piston rod of the auxiliary oil cylinder 500 from collision damage.

Further, a plurality of foot pedals 340 are further provided on the boom 310, and the plurality of foot pedals 340 are spaced apart along the length direction of the boom 310. The foot pedal 340 is provided to facilitate an operator to climb onto the boom 310 for routine maintenance of the boom 310 and to quickly ascend to the upper floor for evacuation in an emergency by ascending the foot pedal 340 to the top of the boom 310.

It is to be understood that the above examples of the present utility model are provided for clarity of illustration only and are not limiting of the embodiments of the present utility model. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the utility model. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are desired to be protected by the following claims.

Claims (10)

1. The hydraulic system of the working device of the excavator comprises an oil tank (110), an oil pump (120), an oil delivery reversing valve (130) and a bucket rod oil cylinder (140), wherein the oil tank (110) is communicated with an oil inlet of the oil pump (120), and an oil outlet of the oil pump (120) is communicated with an oil inlet of the oil delivery reversing valve (130);

hydraulic oil in the oil tank (110) can sequentially pass through the oil pump (120), the oil delivery reversing valve (130) and the oil distribution assembly and is conveyed to the rodless cavity of the bucket rod oil cylinder (140) so as to push the piston rod of the bucket rod oil cylinder (140) to extend outwards, and the oil distribution assembly can conduct oil pipe on-off control so as to convey the hydraulic oil output through the rod cavity of the bucket rod oil cylinder (140) into the rodless cavity of the bucket rod oil cylinder (140) again so as to increase the extending speed of the piston rod.

2. The excavator working device hydraulic system of claim 1 wherein the oil distribution assembly comprises a first cartridge valve (150), a second cartridge valve (160), a differential reversing valve (170) and a shuttle valve (180); wherein,,

two working oil ports of the oil delivery reversing valve (130) are respectively communicated with an a1 oil port of the first cartridge valve (150) and a b1 oil port of the second cartridge valve (160) through a first oil pipe (191) and a second oil pipe (192), an a2 oil port of the first cartridge valve (150) is communicated with a b2 oil port of the second cartridge valve (160) through a third oil pipe (193), a rod cavity of the bucket rod oil cylinder (140) is communicated with the third oil pipe (193) through a fourth oil pipe (194), a rod-free cavity of the bucket rod oil cylinder (140) is communicated with the first oil pipe (191) through a fifth oil pipe (195), the fifth oil pipe (195) and the second oil pipe (192) are respectively communicated with a c1 oil inlet and a c2 oil inlet of the shuttle valve (180), an oil outlet of the shuttle valve (180) is communicated with an oil inlet of the differential reversing valve (170), and two working oil ports of the differential reversing valve (170) are respectively communicated with the first oil port (150 a 3) and the cartridge valve (160 b).

3. The excavator working device hydraulic system according to claim 2, wherein the differential directional valve (170) is provided as a two-position four-way electromagnetic directional valve; the oil delivery reversing valve (130) is arranged as a two-position four-way electromagnetic reversing valve.

4. An excavator comprising the excavator work device hydraulic system of any one of claims 2 to 3, further comprising:

a body (200);

arm support subassembly, including movable arm (310) and arm (320), the first end of movable arm (310) with organism (200) are articulated, the second end of movable arm (310) with the first end of arm (320) is articulated, the second end of arm (320) is articulated to be provided with assist utensil (330), first cartridge valve (150), second cartridge valve (160) differential switching-over valve (170) and shuttle valve (180) all locate on movable arm (310), the cylinder body and the piston rod of arm hydro-cylinder (140) respectively with movable arm (310) with arm (320) are articulated, just arm hydro-cylinder (140) set up in the below of movable arm (310).

5. The excavator according to claim 4, wherein the boom (310) comprises a first straight section (311) and a second straight section (312), the first straight section (311) and the second straight section (312) are connected by an arc bending section (313), the first straight section (311) is hinged to the machine body (200), the second straight section (312) is hinged to the arm (320), and first reinforcing plates (314) are arranged on two opposite sides of the arc bending section (313).

6. The excavator according to claim 5, wherein the arm (320) is provided with second stiffening plates (321) on opposite sides.

7. The excavator of claim 4 further comprising a boom cylinder (400), the boom cylinder (400) cylinder and piston rod being hinged to the machine body (200) and the boom (310) respectively, the boom cylinder (400) being disposed below the boom (310).

8. The excavator of claim 4 further comprising an implement cylinder (500), the implement cylinder (500) cylinder and piston rod being hinged to the stick (320) and the implement (330), respectively.

9. The excavator according to claim 4, wherein the machine body (200) is further provided with a cab (210), and a floor (211) of the cab (210) is sunk into a frame of the machine body (200).

10. The excavator of claim 4 wherein the boom (310) is further provided with a plurality of foot pedals (340), the plurality of foot pedals (340) being spaced apart along the length of the boom (310).