CN214945371U - Pneumatic control composite hydraulic reversing valve - Google Patents

Abstract

The utility model belongs to the technical field of hydraulic systems of dump trucks, in particular to a pneumatic control composite hydraulic reversing valve, wherein the pneumatic control composite hydraulic reversing valve (1) comprises an integral hydraulic reversing valve set, an oil inlet (28), an oil return port (34) and a pneumatic control component; the integral hydraulic reversing valve group comprises three hydraulic reversing valves which are transversely connected, wherein the three hydraulic reversing valves which are transversely connected are respectively a primary reversing valve, a secondary reversing valve and a tertiary reversing valve; compared with the prior art, the pneumatic control composite hydraulic reversing valve of the utility model can control three oil paths with different pressures and flows which alternately run only by using a quantitative oil pump for oil supply, and can replace the original oil path in the third structural scheme of the background technology controlled by three valves only by using a pneumatic control composite hydraulic reversing valve; the pneumatic control composite hydraulic reversing valve is not only used for a dumper, but also can be widely used for similar hydraulic loops.

Description

Pneumatic control composite hydraulic reversing valve

Technical Field

The utility model discloses a belong to tipper hydraulic system technical field, concretely relates to compound hydraulic reversing valve of gas accuse.

Background

At present, most of the transportation of a large amount of bulk materials such as sand, stones, mineral products, coal and muck in the society is preferably finished by a dumper. In the transportation process of the vehicles, the carried goods can scatter and fall in different degrees, and the dust is blown by wind and is scattered all over the day, so that the environmental protection requirement is seriously endangered. In recent years, with the development and progress of society and the improvement of environmental protection, the above vehicles need to be provided with automatic or semi-automatic closing devices, such as currently adopted push-pull tarpaulin covers, double butterfly covers, integral environmental protection covers, and the like. These vehicles are also required to be equipped with a tailgate automatic hydraulic latch device for the purpose of improving the degree of automation and loading and unloading efficiency.

Although the dump trucks have various varieties and series, the hydraulic lifting and dumping devices are basically adopted to carry out manual automatic unloading. Although different hydraulic lifting self-discharging devices of various self-discharging vehicles are provided, the working principles of various hydraulic lifting systems are approximately equivalent, and the working pressure of the hydraulic lifting systems is generally in the range of 18-24 MPa.

The opening and closing of the environmental protection cover (the sealing device) are roughly divided into three types, the first type is to drive a speed reducer by a motor to drive the opening and closing of the environmental protection cover, and the environmental protection cover is mainly used for a tarpaulin cover structure; the second is to use the motor to drive the oil pump to establish the independent hydraulic system to control the opening and closing of the environmental protection cover, which is mostly used for the butterfly cover structure, and the system working pressure is generally in the range of 12-16 Mpa; the third is to drive a duplex oil pump by the gearbox and the power takeoff of the vehicle through a universal transmission shaft to an oil pump support, one duplex oil is used for connecting a lifting valve for controlling unloading, and the working pressure of the duplex oil pump is generally in the range of 18-24 MPa; the other oil outlet is connected with a hydraulic reversing valve → a two-way balance valve → an environment-friendly cover oil cylinder which controls the environment-friendly cover, and the other oil outlet is mainly used for the integral environment-friendly cover and double-part butterfly cover structure, and the working pressure of the system is generally within the range of 12-16 MPa. The hydraulic reversing valve → two-way oil motor is also used for connecting a control environmental protection cover to drive the tarpaulin cover structure, and the working pressure is in the range of 10-12 Mpa. If a vehicle with a tailgate hydraulic coupler lock device is required, a duplex pump is changed into a triple pump, and a hydraulic reversing valve for controlling a hydraulic coupler is additionally connected to the triple pump, wherein the working pressure of the hydraulic reversing valve is generally within the range of 8-1 OMa.

The practice proves that the first method overcomes the defects of small overload potential, easy motor burning and high failure rate due to irregular goods loading, blocked opening and closing of the tarpaulin cover and the like. And the other hydraulic system is an independent hydraulic station driven by a motor and specially used for opening and closing the environment-friendly cover. The scheme has the advantages of complex structure, large occupied space, high cost, easy motor burning and the like. The two structures have the motor which is arranged on the outer surface of the vehicle body, so that the temperature rise and the humidity are difficult to avoid being exposed to the sun and the rain, the insulation is damaged, and the motor is easy to burn. In view of the above two defects and shortcomings, the existing individual manufacturer is changed into the third structure, and the structure has the defects of high cost, complex structure, large dead weight, inconvenience in installation, disordered and complex pipelines, large installation space, high failure rate, inconvenience in maintenance and the like.

SUMMERY OF THE UTILITY MODEL

The utility model provides a compound hydraulic reversing valve of gas accuse to the above-mentioned hydraulic system structure is complicated, occupation space is big, with high costs scheduling problem.

In order to achieve the above object, the utility model discloses a technical scheme be: a pneumatic control composite hydraulic reversing valve comprises an integral hydraulic reversing valve group, an oil inlet, an oil return port and a pneumatic control assembly;

the integral hydraulic reversing valve group comprises three hydraulic reversing valves which are transversely connected, wherein the three hydraulic reversing valves which are transversely connected are respectively a primary reversing valve, a secondary reversing valve and a tertiary reversing valve;

the primary reversing valve comprises a first valve body and a first valve core, the first valve core is arranged in a cavity of the first valve body, and the length direction of the first valve core is parallel to the longitudinal direction of the first valve body; the two-stage reversing valve comprises a second valve body and a second valve core, the second valve core is arranged in a cavity of the second valve body, and the length direction of the second valve core is parallel to the longitudinal direction of the second valve body; the three-stage reversing valve comprises a third valve body and a third valve core, the third valve core is arranged in a cavity of the third valve body, and the length direction of the third valve core is parallel to the longitudinal direction of the third valve body;

the first valve core, the second valve core and the third valve core respectively comprise a plurality of middle shoulders, two end shoulders and a plurality of undercut grooves; the plurality of undercut grooves are respectively positioned between the adjacent shoulders;

the first valve body, the second valve body and the third valve body are transversely aligned and sequentially and transversely arranged to form a main valve body of the integral pneumatic control composite hydraulic reversing valve, and two oil inlet passages are formed in the longitudinal middle parts of the first valve body, the second valve body and the third valve body;

the oil inlet is formed in the two sides, far away from the valve body, of the first valve body, and is communicated with two oil inlet passages in the first valve body, the second valve body and the third valve body;

when the pneumatic control composite hydraulic reversing valve is in a non-working state, the two oil inlet passages are respectively communicated with the undercut grooves among the shoulders of the first valve core, the second valve core and the third valve core;

a main valve body of the pneumatic control composite hydraulic reversing valve is internally provided with a transverse front oil return channel and a transverse rear oil return channel; when the pneumatic control composite hydraulic reversing valve is in a non-working state, two end part circular beads of the first valve core, the second valve core and the third valve core respectively longitudinally penetrate through the front oil return channel and the rear oil return channel and can block the front oil return channel and the rear oil return channel;

the oil return port is formed in the two sides, far away from the valve body, of the valve body III, an oil return passage L is arranged between the valve body III and the valve body II, and the oil return passage L is respectively communicated with the front oil return passage and the oil return port, and the rear oil return passage and the oil return port; the two oil inlet passages are far away from the oil inlet end and communicated with the oil return port;

the pneumatic control assembly comprises three cylinders, the three cylinders are respectively a cylinder I, a cylinder II and a cylinder III, piston rods of the cylinder I, the cylinder II and the cylinder III are respectively designed at the end parts of the valve core I, the valve core II and the valve core III in the length direction and are integrated with the valve core, and the piston rods can drive the valve core I, the valve core II and the valve core III to longitudinally move;

the first valve body, the second valve body and the third valve body are respectively provided with oil ports, and the oil ports are respectively connected with oil ports of an external oil cylinder through pipelines; and when the pneumatic control composite hydraulic reversing valve is in a non-working state, oil ports of the first valve body, the second valve body and the third valve body respectively correspond to the undercut grooves adjacent to the end shoulders of the first valve core, the second valve core and the third valve core.

Preferably, the pneumatic control composite hydraulic reversing valve is mounted on a dump truck, two oil ports of the first valve body, the second valve body and the third valve body are respectively connected with a lifting oil cylinder, an environment-friendly cover opening and closing oil cylinder and a tail plate opening and closing oil cylinder, the oil inlet (28) is connected with an oil pump outlet of a hydraulic system, and the oil return port (34) is communicated with a hydraulic oil tank (5) of the dump truck for oil return.

Preferably, the first valve body is provided with a lifting oil port, the lifting oil cylinder is a single-acting oil cylinder with only one oil port, and the lifting oil port is communicated with the oil port of the lifting oil cylinder; the second valve body is provided with a cover closing oil port and a cover opening oil port which are respectively communicated with a front oil port and a rear oil port of the environment-friendly cover opening and closing oil cylinder; the valve body three opening is provided with a tail plate closing oil port and a tail plate opening oil port, and the tail plate closing oil port and the tail plate opening oil port are respectively communicated with the front oil port and the rear oil port of the tail plate opening and closing oil cylinder.

Preferably, the cylinder III also comprises a cylinder barrel III and a movable piston III; the two longitudinal ends of the cylinder barrel III are respectively provided with a fixed piston III and a cylinder III rear cover, the movable piston III is arranged at one end, far away from the valve core III, of a piston rod of the cylinder III, and the movable piston III is positioned in the cylinder barrel III and matched with the cylinder barrel III; a related tail plate air port and a related tail plate air port are respectively formed at the position of the cylinder barrel III, which is close to the fixed piston III and the rear cover of the cylinder barrel III;

the second cylinder further comprises a second cylinder barrel and a second movable piston; the two longitudinal ends of the second cylinder barrel are respectively provided with a fixed piston II and a second cylinder rear cover, the second movable piston is arranged at one end, far away from the second valve core, of a piston rod of the second cylinder, and the second movable piston is positioned in the second cylinder barrel and matched with the second cylinder barrel; a cover closing air port and a cover opening air port are respectively formed in the cylinder barrel II close to the fixed piston II and the rear cover of the cylinder barrel II;

the first cylinder further comprises a first cylinder barrel and a first movable piston; the two longitudinal ends of the first cylinder barrel are respectively provided with a first fixed piston and a first air cylinder rear cover, the first movable piston is arranged at one end, far away from the first valve core, of a piston rod of the first air cylinder, and the first movable piston is located in the first cylinder barrel and matched with the first cylinder barrel; and a descending air port and a lifting air port are respectively formed at the positions of the cylinder barrel I, which are close to the fixed piston I and the cylinder I and the rear cover.

Preferably, a slow-lowering piston is further installed between the lifting air port of the first air cylinder and the rear cover of the first air cylinder, the slow-lowering piston is matched with the first cylinder barrel of the first air cylinder, an adjusting rod is vertically and fixedly connected to the center of the end, close to the rear cover of the first air cylinder, of the slow-lowering piston, the end, far away from the slow-lowering piston, of the adjusting rod penetrates through the rear cover of the first air cylinder, and the adjusting rod can move longitudinally along the first cylinder barrel under the driving of the slow-lowering piston; a slow-down air port is formed in the first rear cover of the air cylinder.

Preferably, the first valve core comprises two middle shoulders, two end shoulders and three undercut grooves, the two middle shoulders are a first shoulder and a second shoulder respectively, the two end shoulders are a third shoulder and a fourth shoulder respectively, and the three undercut grooves are a first undercut groove, a second undercut groove and a third undercut groove respectively; a slow-down notch H is formed at the end, close to the three ends of the undercut groove, of the shoulder four; the second valve core comprises three middle shoulders, two end shoulders and four undercut grooves, wherein the three middle shoulders are a fifth shoulder, a sixth shoulder and a seventh shoulder respectively, the two end shoulders are an eighth shoulder and a ninth shoulder respectively, and the four undercut grooves are a fourth undercut groove, a fifth undercut groove, a sixth undercut groove and a seventh undercut groove respectively; the third valve core comprises three middle shoulders, two end shoulders and four undercut grooves, the three middle shoulders are respectively a tenth shoulder, a eleventh shoulder and a twelfth shoulder, the two end shoulders are respectively a thirteenth shoulder and a fourteen shoulder, and the four undercut grooves are respectively an eighth undercut groove, a ninth undercut groove, a tenth undercut groove and an eleventh undercut groove.

Preferably, the pneumatic control composite hydraulic reversing valve further comprises a plurality of overflow valves, and the overflow valves are respectively a primary overflow valve, a secondary overflow valve and a tertiary overflow valve; the first-level overflow valve is installed on an oil inlet passage of the first valve body, the second-level overflow valve is installed on an oil inlet passage K between the first valve body and the second valve body, and the third-level overflow valve is installed on an oil inlet passage K2 between the third valve body and the second valve body.

Preferably, flow control valves are arranged in the front oil return channel between the first valve body and the second valve body and in the front oil return channel between the third valve body and the second valve body.

Preferably, the ends of the first valve core, the second valve core and the third valve core, which are far away from the cylinder assembly, are provided with vent covers.

Compared with the prior art, the utility model discloses an advantage lies in with positive effect:

compared with the prior art, the utility model discloses a compound hydraulic reversing valve of gas accuse, (1) only use a quantitative oil pump fuel feeding, steerable three oil circuit of the different pressures of operation in turn and flow to only use compound hydraulic reversing valve of gas accuse just can replace the original oil circuit in the third kind of structural scheme of background art who controls with three valves. The pneumatic control composite hydraulic reversing valve is not only used for a dumper, but also can be widely used for similar hydraulic loops;

(2) the primary overflow valve is arranged on the oil inlet passage of the first valve body, the secondary overflow valve is arranged on the oil inlet passage K between the first valve body and the second valve body, the tertiary overflow valve is arranged on the oil inlet passage K2 between the third valve body and the second valve body, and the set pressures of the primary overflow valve, the secondary overflow valve and the tertiary overflow valve can be different, so that one air-controlled composite hydraulic reversing valve controls three oil passages with different pressures;

(3) and flow control valves are arranged in the front oil return channel between the first valve body and the second valve body and in the front oil return channel between the third valve body and the second valve body, so that one air control composite hydraulic reversing valve controls three oil ways with different flows.

Drawings

In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings required to be used in the description of the embodiment will be briefly introduced below, and fig. 1 is an application schematic diagram of the pneumatic control composite hydraulic directional valve provided in embodiment 1;

FIG. 2 is a front view of a pneumatically controlled compound hydraulic directional valve;

FIG. 3 is a schematic view of the pneumatic control composite hydraulic directional valve in a non-working state (the valve core is in a neutral position);

FIG. 4 is a cross-sectional view of a pneumatic control compound hydraulic directional valve A-A;

FIG. 5 is a schematic view of the pneumatic control composite hydraulic directional control valve when the valve core III moves to the left end tail plate and is opened;

FIG. 6 is a schematic view of the pneumatic control composite hydraulic directional control valve when the valve core III moves to the right end tail plate and is closed;

FIG. 7 is a schematic diagram of the pneumatic control composite hydraulic directional control valve when the valve core II moves to the left end and the protective cover is opened;

FIG. 8 is a schematic diagram of the pneumatic control composite hydraulic directional control valve when the second valve core moves to the right environmental protection cover;

FIG. 9 is a schematic view of the pneumatic control composite hydraulic directional control valve when the first valve core moves to the left end to lift the oil cylinder;

FIG. 10 is a schematic view of the pneumatic control composite hydraulic directional control valve when the piston rod of the lifting cylinder descends when the valve core moves to the right end;

FIG. 11 is a schematic view of a pneumatic control compound hydraulic directional control valve when the cargo box is slowly lowered;

fig. 12 is an application schematic diagram of the pneumatic control composite hydraulic directional valve provided in embodiment 2;

FIG. 13 is a right side view of the pneumatically controlled compound hydraulic directional valve;

FIG. 14 is a left side view of the pneumatically controlled compound hydraulic directional valve;

FIG. 15 is a schematic structural view of a valve core II;

FIG. 16 is a schematic view of a valve cartridge with three structures;

FIG. 17 is a schematic view of a valve cartridge configuration;

FIG. 18 is a rear view of a pneumatically controlled compound hydraulic directional valve.

Description of the drawings:

1-a pneumatic control composite hydraulic reversing valve, 2-a tail plate switch oil cylinder, 3-an environment-friendly cover opening and closing oil cylinder, 4-a lifting oil cylinder and 5-a hydraulic oil tank;

6, a first valve core, 61, a first shoulder, 62, a second shoulder, 63, a third shoulder, 64, a fourth shoulder, 65, a first undercut groove, 66, a second undercut groove and 67, a third undercut groove;

7-a ventilation cover and 8-a secondary overflow valve;

9-valve core two, 91-shoulder five, 92-shoulder seven, 93-shoulder eight, 94-shoulder nine, 95-shoulder six, 96-undercut groove four, 97-undercut groove five, 98-undercut groove six, 99-undercut groove seven;

10-three-level overflow valve;

11-three valve core, 111-ten shoulder, 112-twelve shoulder, 113-thirteen shoulder, 114-fourteen shoulder, 115-eleven shoulder, 116-eight undercut groove, 117-nine undercut groove, 118-ten undercut groove, 119-eleven undercut groove;

12-cylinder three, 121-opening tail plate air port, 122-closing tail plate air port;

13-a third return spring, 14-a third fixed piston, 15-a third movable piston, 16-a third cylinder rear cover, 17-a second return spring, 18-a second fixed piston, 19-a second movable piston;

20-cylinder two, 201-cover opening air port, 202-cover closing air port;

21-cylinder one, 211-lift port, 212-lower port;

22-fixed piston I, 23-movable piston I, 24-adjusting rod, 25-slow-lowering piston, 26-cylinder-rear cover, 27-return spring I, 28-oil inlet, 29-primary overflow valve, 30-cover closing oil port, 31-cover opening oil port, 32-tail plate opening oil port, 33-tail plate closing oil port, 34-oil return port, 35-front oil return channel, 36-rear oil return channel, 37-mounting screw hole, 38-flow control valve and 39-lifting oil port.

Detailed Description

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be further described with reference to the accompanying drawings and examples.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the present invention is not limited to the limitations of the specific embodiments of the present disclosure.

Example 1

The present invention will be further described with reference to fig. 1-17, and an air-controlled composite hydraulic directional control valve, as shown in fig. 3-10, 13 and 14, the air-controlled composite hydraulic directional control valve 1 includes an integral hydraulic directional control valve set, an oil inlet 28, an oil return 34 and an air-controlled assembly.

As shown in fig. 3-10, 13 and 14, the integral hydraulic directional valve set comprises three transversely arranged integral hydraulic directional valves, wherein the three transversely arranged hydraulic directional valves are a primary directional valve, a secondary directional valve and a tertiary directional valve respectively; the primary reversing valve comprises a first valve body and a first valve core 6, the first valve core 6 is arranged in a cavity of the first valve body, and the length direction of the first valve core 6 is parallel to the longitudinal direction of the first valve body; the two-stage reversing valve comprises a second valve body and a second valve core 9, the second valve core 9 is arranged in a cavity of the second valve body, and the length direction of the second valve core 9 is parallel to the longitudinal direction of the second valve body; the three-stage reversing valve comprises a third valve body and a third valve core 11, wherein the third valve core 11 is arranged in a cavity of the third valve body, and the length direction of the third valve core 11 is parallel to the longitudinal direction of the third valve body.

As shown in fig. 15-17, the first valve core 6, the second valve core 9 and the third valve core 11 each include a plurality of intermediate lands, two end lands and a plurality of undercut grooves; the plurality of undercut grooves are respectively located between adjacent shoulders.

As shown in fig. 3-10, the first valve body, the second valve body and the third valve body are transversely aligned and sequentially transversely arranged to form a main valve body of the pneumatic control composite hydraulic reversing valve 1, namely, the pneumatic control composite hydraulic reversing valve of the utility model is of an integral structure, and two oil inlet passages are arranged at the longitudinal middle parts of the first valve body, the second valve body and the third valve body.

As shown in fig. 3, 10 and 11, two oil inlet passages from the oil inlet 28 to the oil return port 34 include oil inlet passages K, K1 and K2, a first valve body undercut groove e, second valve body undercut grooves c and d, and third valve body undercut grooves a and b.

As shown in fig. 3-10, the oil inlet 28 is opened at the two sides of the first valve body far from the first valve body, and the oil inlet 28 is communicated with two oil inlet passages in the first valve body, the second valve body and the third valve body.

When the pneumatic control composite hydraulic directional valve 1 is in a non-working state (as shown in fig. 3), the two oil inlet passages are respectively communicated with the undercut grooves among the shoulders of the first valve core 6, the second valve core 9 and the third valve core 11.

As shown in fig. 3 and 4, a front transverse oil return passage 35 and a rear transverse oil return passage 36 are formed in the main valve body of the pneumatic control compound hydraulic directional valve 1; the front oil return passage 35 and the rear oil return passage 36 are separated from the oil inlet passages (K, K1 and K2).

As shown in fig. 3, when the pneumatic control compound hydraulic directional valve 1 is in a non-operating state, two end lands of the first valve element 6, the second valve element 9 and the third valve element 11 respectively longitudinally penetrate through the front oil return passage 35 and the rear oil return passage 36, and can block the front oil return passage 35 and the rear oil return passage 36.

As shown in fig. 3-10, the oil return port 34 is formed on two sides of the third valve body, which are far away from the second valve body, an oil return passage L is formed between the third valve body and the second valve body, and the oil return passage L is respectively communicated with the front oil return passage 35 and the oil return port 34, and the rear oil return passage 36 and the oil return port 34; the ends of the two oil inlet passages away from the oil inlet 28 communicate with the oil return port 34; the front oil return passage 35 and the rear oil return passage 36 are respectively communicated with the oil return passage L, and communicated with the oil return port 34 through the oil return passage L; the oil return passage L and the oil inlet passage are not on the same plane and are mutually separated.

As shown in fig. 3-10, the pneumatic control assembly includes three cylinders, the three cylinders are respectively a first cylinder 21, a second cylinder 20 and a third cylinder 12, piston rod portions of the first cylinder 21, the second cylinder 20 and the third cylinder 12 are respectively designed at one end portion of the first valve core 6, the second valve core 9 and the third valve core 11 in the length direction, and are of an integrated structure, and the first valve core 6, the second valve core 9 and the third valve core 11 can be driven to move longitudinally.

As shown in fig. 2-10, the first valve body, the second valve body and the third valve body are respectively provided with oil ports, and the oil ports are respectively connected with oil ports of an external oil cylinder through pipelines; when the pneumatic control composite hydraulic reversing valve 1 is in a non-working state, oil ports of the first valve body, the second valve body and the third valve body respectively correspond to the undercut grooves adjacent to the end shoulders of the first valve core 6, the second valve core 9 and the third valve core 11.

As shown in fig. 1 and 2, the pneumatic control composite hydraulic directional control valve 1 is installed on a dump truck, two oil ports of a first valve body, a second valve body and a third valve body are respectively connected with a lifting oil cylinder 4, an environmental protection cover opening and closing oil cylinder 3 and a tail plate opening and closing oil cylinder 2, an oil return port 34 is respectively communicated with a hydraulic oil tank 5 of the dump truck, and a hydraulic oil pump is arranged between an oil inlet 28 and the hydraulic oil tank 5.

As shown in fig. 1, 2 and 9, a lifting oil port 39 is formed in the first valve body, the lifting oil cylinder 4 is a single-acting cylinder with only one oil port, and the lifting oil port 39 is communicated with the oil port of the lifting oil cylinder 4.

As shown in fig. 2 to 10, the second valve body is provided with a cover closing oil port 30 and a cover opening oil port 31, and the cover closing oil port 30 and the cover opening oil port 31 are respectively communicated with the front oil port and the rear oil port of the environment-friendly cover opening and closing oil cylinder 3.

As shown in fig. 2-10, the third valve body is provided with a tail plate oil port 33 and a tail plate oil port 32, and the tail plate oil port 33 and the tail plate oil port 32 are respectively communicated with the front oil port and the rear oil port of the tail plate switch oil cylinder 2.

As shown in fig. 3, the cylinder three 12 further includes a cylinder barrel three and a movable piston three 15; the two longitudinal ends of the cylinder barrel III are respectively provided with a fixed piston III 14 and a cylinder III rear cover 16, a movable piston III 15 is arranged at one end, far away from the valve core III 11, of a piston rod of the cylinder III 12, and the movable piston III 15 is positioned in the cylinder barrel III and matched with the cylinder barrel III; and the cylinder barrel III is provided with a tail plate air port 122 and a tail plate air port 121 respectively close to the fixed piston III 14 and the cylinder III rear cover 16.

As shown in fig. 3, the second cylinder 20 further includes a second cylinder barrel and a second movable piston 19; a fixed piston II 18 and a cylinder II rear cover are respectively arranged at the two longitudinal ends of the cylinder II, a movable piston II 19 is arranged at one end, far away from the valve core II 9, of a piston rod of the cylinder II 20, and the movable piston II 19 is positioned in the cylinder II and matched with the cylinder II; and a cover closing air port 202 and a cover opening air port 201 are respectively formed in the cylinder barrel II close to the fixed piston II 18 and the rear cover of the cylinder barrel II.

As shown in fig. 3, the first cylinder 21 further comprises a first cylinder barrel and a first movable piston 23; a fixed piston I22 and a cylinder I rear cover 26 are respectively arranged at the two longitudinal ends of the cylinder I, a movable piston I23 is arranged at one end, far away from the valve core I6, of a piston rod of the cylinder I21, and the movable piston I23 is positioned in the cylinder I and matched with the cylinder I; the cylinder barrel I is provided with a descending air port 212 and a lifting air port 211 respectively close to the fixed piston I22 and the cylinder I rear cover 26.

As shown in fig. 3 and 11, a slow-down piston 25 is further installed between the lift gas port 211 of the first cylinder 21 and the first cylinder rear cover 26, the slow-down piston 25 is matched with the first cylinder barrel of the first cylinder 21, the center of the slow-down piston 25, which is close to the first cylinder rear cover 26 end, is vertically and fixedly connected with an adjusting rod 24, the end of the adjusting rod 24, which is far away from the slow-down piston 25, penetrates through the first cylinder rear cover 26, and the adjusting rod 24 can move longitudinally along the first cylinder barrel under the driving of the slow-down piston 25; the cylinder-rear cover 26 is provided with a slow-down air port 213.

As shown in fig. 17, the first valve core 6 includes two middle lands, two end lands and three undercut grooves, the two middle lands are a first land 61 and a second land 62 respectively, the two end lands are a third land 63 and a fourth land 64 respectively, and the three undercut grooves are an undercut groove 65, an undercut groove 66 and an undercut groove 67 respectively; the end of the shoulder four 64 close to the undercut groove three 67 is provided with a slow-down gap H.

As shown in fig. 15, the second valve element 9 includes three intermediate lands, namely a fifth land 91, a sixth land 95 and a seventh land 92, two end lands, namely an eighth land 93 and a ninth land 94, and four undercut grooves, namely an undercut groove four 96, an undercut groove five 97, an undercut groove six 98 and an undercut groove seven 99.

As shown in fig. 16, the valve element three 11 includes three intermediate lands, i.e., a land ten 111, a land eleven 115, and a land twelve 112, two end lands, i.e., a land thirteen 113 and a land fourteen 114, and four undercut grooves, i.e., an undercut groove eight 116, an undercut groove nine 117, an undercut groove ten 118, and an undercut groove eleven 119.

As shown in fig. 3 to 11, the pneumatic control composite hydraulic directional valve 1 further includes a plurality of overflow valves, which are a primary overflow valve 29, a secondary overflow valve 8, and a tertiary overflow valve 10, respectively.

As shown in fig. 3 to 11, the primary overflow valve 29 is installed on the oil inlet passage of the first valve body, the secondary overflow valve 8 is installed on the oil inlet passage K between the first valve body and the second valve body, and the tertiary overflow valve 10 is installed on the oil inlet passage K2 between the third valve body and the second valve body.

As shown in fig. 4, a flow control valve 38 is disposed in the front oil return passage 35 between the first valve body and the second valve body, and in the front oil return passage 35 between the third valve body and the second valve body.

As shown in fig. 3-10, the ends of the first valve core 6, the second valve core 9 and the third valve core 11 far away from the cylinder assembly are all provided with a ventilation cover 7.

The pneumatic control composite hydraulic directional valve 1 is provided with four mounting screw holes 37.

The utility model discloses a compound hydraulic pressure switching-over valve 1 theory of operation of gas accuse:

(1) and (3) non-working state: as shown in fig. 3, when the right cylinder one 21, the cylinder two 20 and the cylinder three 12 are not operated, the valve core one 6, the valve core two 9 and the valve core three 11 are in a balanced state under the action of the pre-pressures of the return spring one 27, the return spring two 17 and the return spring three 13, respectively, as shown in fig. 3. At this time, the lifting oil port 39 is completely closed by the first valve core 6, and the lifting oil cylinder 4 is in a static state, namely, the cargo box is in a static state. The cover closing oil port 30 and the cover opening oil port 31 are both closed by the second valve core 9, and the environment-friendly cover opening and closing oil cylinder 3 of the environment-friendly cover is driven to be in a static state, namely the environment-friendly cover is in a static state. The switch tail plate oil port 32 and the switch tail plate oil port 33 are both closed by the valve core III 11, and the tail plate switch oil cylinder 2 is in a static closed state.

When oil fed by the oil feed pump enters the main valve body through the oil inlet 28, enters the two undercut grooves (undercut groove four 96 and undercut groove five 97) in the middle of the valve core two 9 through the oil inlet passage K (marked by dotted lines) through the undercut groove two 66 in the middle of the valve core one 6, is respectively communicated with the valve body undercut grooves d and c of the valve body two 9 and then passes through the oil inlet passage KI, k2 (dotted line marks) enters two undercut grooves (undercut groove eight 116 and undercut groove nine 117) in the middle of the valve core three 11, the two undercut grooves (undercut groove eight 116 and undercut groove nine 117) in the middle of the valve core three 11 are respectively communicated with two valve body undercut grooves b and a in the middle of the valve body three, the two valve body undercut grooves a and b in the middle of the valve body three are communicated with the oil return port 34, oil return is carried out through the oil return port 34, at the moment, the hydraulic system is in a non-pressure unloading state, and the matched power loss is very small.

(2) Switch of tail plate

And (3) opening the tail plate: as shown in FIG. 5, when the air is exhausted from the closing plate air port 122 and the air is introduced from the opening plate air port 121, the movable piston III 15 drives the valve core III 11 to overcome the axial thrust of the return spring III 13 and move to the left until the left dead center under the action of the air pressure. The pressure oil enters the main valve body through the oil inlet 28, enters two undercut grooves (an undercut groove four 96 and an undercut groove five 97) in the middle of the valve core two 9 through an oil inlet passage K through an undercut groove (an undercut groove two 66) in the middle of the valve core one 6, enters a undercut groove ten 118 in the right end of the valve core three 11 through an oil inlet passage K1 (a shoulder twelve 112 prevents the hydraulic oil from entering a valve body undercut groove b of the valve body three, a shoulder eleven 115 prevents the hydraulic oil from entering a valve body undercut groove a of the valve body three, and a shoulder ten 111 prevents the hydraulic oil from communicating with the tail plate oil port 33), and is directly supplied to the tail plate opening end of the tail plate switch oil cylinder 2 through the tail plate opening oil port 32; the oil returned from the other end of the tail plate switch oil cylinder 2 to the tail plate oil port 33 passes through the rear oil return channel 36, the oil return passage L and returns to the hydraulic oil tank 5 through the oil return port 34 via the left undercut groove eleven 119 of the valve core III 11; and carrying out tail opening plate operation. If overload occurs during operation, the three-stage overflow valve 10 is automatically opened to return oil through the rear oil return channel 36, the oil return passage L and the oil return port 34.

Closing the tail plate: as shown in FIG. 6, when the exhaust port 121 of the open end plate exhausts air and the exhaust port 122 of the close end plate admits air, the movable piston III 15 drives the valve core III 11 to move rightwards to the right dead center against the axial thrust of the return spring III 13 under the action of air pressure. The pressure oil enters the main valve body through the oil inlet 28, enters two undercut grooves (an undercut groove four 96 and an undercut groove five 97) in the middle of the valve core two 9 through an oil inlet passage K through an undercut groove (an undercut groove two 66) in the middle of the valve core one 6, enters an undercut groove eleven 119 at the left end of the valve core three 11 through an oil inlet passage K2 (a shoulder ten 111 prevents the hydraulic oil from entering a valve body undercut groove a of the valve body three, a shoulder eleven 115 prevents the hydraulic oil from entering a valve body undercut groove b of the valve body three, and a shoulder twelve 112 prevents the hydraulic oil from communicating with the tail opening plate oil port 32), and is directly communicated with the tail closing plate oil port 33 to supply oil to the tail closing plate end of the tail plate switch oil cylinder 2; the other end of the tail plate switch oil cylinder 2 returns to the tail plate opening 32, passes through the front oil return channel 35, the oil return passage L and returns to the hydraulic oil tank 5 through the oil return opening 34 via the undercut groove 118 on the right side of the valve core III 11.

(3) Switch environmental protection cover

Opening the environment-friendly cover: as shown in fig. 7, when the cover closing air port 202 exhausts air, the cover opening air port 201 admits air, the movable piston two 19 drives the valve core two 9 and overcomes the axial thrust of the return spring two 17 to move to the left until the left end dead point under the action of air pressure. The pressure oil enters the main valve body through the oil inlet 28, enters the undercut groove six 98 at the right end of the valve core two 9 through the oil inlet passage K through the undercut groove (undercut groove two 66) at the middle part of the valve core one 6 (the land six 95 prevents the hydraulic oil from entering the valve body undercut groove c of the valve body two, the land seven 92 prevents the hydraulic oil from entering the valve body undercut groove d of the valve body two, and the land five 91 prevents the hydraulic oil from communicating with the cover opening/closing oil port 30), is directly communicated with the cover opening oil port 31 to supply the oil to the cover opening end of the environmental protection cover opening/closing oil cylinder 3, returns to the cover closing oil port 30 through the undercut groove seven 99 at the left side of the valve core two 9, passes through the rear oil return channel 36, the oil return passage L and returns to the hydraulic oil tank 5 through the oil return port 34 to perform the cover opening operation. If overload occurs during work, the secondary overflow valve 8 is automatically opened to return oil through the rear oil return channel 36 and the oil return passage L.

Closing the environment-friendly cover: as shown in fig. 8, when the cover opening port 201 exhausts air, the cover closing port 202 admits air, and the movable piston two 19 drives the valve core two 9 to move rightwards to the right dead center against the axial thrust of the return spring two 17 under the action of air pressure. The pressure oil enters the main valve body through the oil inlet 28, passes through the oil inlet passage K through the undercut groove (undercut groove II 66) in the middle of the valve core I6, enters the undercut groove seventh 99 at the left end of the valve core II 9 (hydraulic oil is prevented from entering the valve body undercut groove d of the valve body II by shoulder six 95, hydraulic oil is prevented from entering the valve body undercut groove c of the valve body II by shoulder five 91, hydraulic oil is prevented from communicating with the cover opening port 31 by shoulder seven 92), and is directly fed to the cover closing port 30 to be fed to the cover closing end of the environmental protection cover opening and closing oil cylinder 3; the other end of the environment-friendly cover opening and closing oil cylinder 3 returns oil to the cover opening oil port 31, passes through the front oil return channel 35 and the oil return passage L through the sinking and cutting groove six 98 on the right side of the valve core II 9 and returns to the hydraulic oil tank 5 through the oil return port 34; and (5) closing the cover. If overload occurs during work, the secondary overflow valve 8 is automatically opened to return oil through the rear oil return channel 36 and the oil return passage L.

(4) Container lifting and lowering

Lifting the container: as shown in FIG. 9, when the descending air port 212 exhausts air, the lifting air port 211 intakes air, the slow descending air port 213 exhausts air, the movable piston I23 drives the valve core I6 under the action of air pressure, overcomes the axial thrust of the return spring I27, moves leftwards to the left end dead center, and moves rightwards to the dead center by the slow descending piston 25. At the moment, the pressure oil flows to the main valve body through the oil inlet 28, passes through the undercut groove III 67 (the shoulder II 62 prevents the hydraulic oil from entering the valve body undercut groove e of the valve body I) at the right end of the valve core I6, and is directly communicated with the lifting oil port 39 to supply the oil to the lifting oil cylinder 4; and carrying out lifting and unloading work. When the lifting system is overloaded during working, the primary overflow valve 29 is automatically opened to return oil through the rear oil return channel 36 and the oil return passage L, so that the overload safety protection effect of the lifting system is achieved.

The cargo box descends: as shown in fig. 10, when the descending gas port 212 admits gas, the lifting gas port 211 exhausts gas, the slow descending gas port 213 exhausts gas, the first movable piston 23 drives the first valve core 6 under the action of air pressure, overcomes the axial thrust of the first return spring 27, and moves right to the right dead center, the slow descending piston 25 is in a free state without external force, the oil pump supplies oil to enter the main valve body through the oil inlet 28, to enter the two undercut grooves (undercut groove four 96 and undercut groove five 97) in the middle of the second valve core 9 through the two undercut grooves (undercut groove one 65 and undercut groove two 66) at the left end of the first valve core 6, to enter the two undercut grooves (undercut groove four 96 and undercut groove five 97) in the middle of the second valve core 9 through the oil inlet passage K1 and K2, to unload and return oil to the oil return port 34 through the two undercut grooves (undercut groove eight 116 and undercut groove nine 117) in the middle of the third valve core 11. The hydraulic oil in the lifting oil cylinder 4 is pressed back to the lifting oil port 39 under the action of the gravity of the cargo box, and then returns to the hydraulic oil tank 5 through the first valve core 6, the third undercut groove 67 at the right end, the front oil return channel 35 and the oil return passage L through the oil return port 34. As seen from the above, the cargo box descends by means of self gravity, and even if the oil pump stops working, the cargo box does not have any influence.

(3) Container slowly falls

As shown in fig. 11, when the cargo box is normally lowered, the gravity acceleration acts on the cargo box, the cargo box is lowered faster, and the downward impact force is applied to the chassis of the frame at the moment of lowering to the bottom, so that the chassis of the frame is damaged correspondingly. To avoid this, the slow descent mode may be switched to when the descent approaches the bottom, as shown in fig. 11, in which the slow descent port 213 is switched from the exhaust state to the intake state in the normal descent mode. The thrust of the slow-falling piston 25 is greater than the thrust of the first movable piston 23, and the acting force of the first return spring 27 is added, so that the slow-falling piston 25 moves leftwards to the dead point of the reducing step of the cylinder, the adjusting rod 24 is driven to push the first movable piston 23, the first valve core 6 moves leftwards to the position shown in the figure, and the first return spring 27 releases and pushes the spring seat to move leftwards to the corresponding shaft shoulder of the first valve core 6. At the moment, oil supplied by the oil pump enters the main valve body through the oil inlet 28, enters the two undercut grooves (the undercut groove I65 and the undercut groove II 66) at the left end of the valve core I6, enters the two undercut grooves (the undercut groove IV 96 and the undercut groove V97) in the middle of the valve core II 9 through the oil inlet passage K, passes through the oil inlet passages K1 and K2, and returns oil to the oil return port 34 for unloading through the two undercut grooves (the undercut groove eight 116 and the undercut groove nine 117) in the middle of the valve core III 11. The hydraulic oil in the lifting oil cylinder 4 is pressed back to the lifting oil port 39 under the action of the gravity of the cargo box, and then returns to the hydraulic oil tank 5 through the first valve core 6, the third undercut groove 67 at the right end, the slow-down notch H, the front oil return channel 35 and the oil return passage L through the oil return port 34. The descending speed is related to the opening size of the slow descending gap H, the opening size of the slow descending gap H can be adjusted through the adjusting rod 24, the smaller the opening is, the slower the descending speed is, and the larger the opening is, the vice versa. The ideal slow-down speed can be realized by adjusting according to the actual situation, and the impact caused by the rapid slow-down to the bottom is avoided. In the normal descending process, the descending speed is faster, and the descending speed can be controlled by slowly descending at any time point.

Example 2

The difference between this example and example 1 is: the lifting of the cargo box can also adopt the structure form shown in the following figure 12, the cargo box is controlled to descend by using manual proportional slow descending, namely, the axial thrust of the movable piston 23 is controlled by manually controlling the air input quantity of the descending air port 212 of the manual proportional air valve to the first air cylinder 21 so as to change the axial position of the first valve core 6, the opening size of the slow descending gap H (namely, the oil return speed of the lifting oil cylinder 4 is controlled), and therefore, the ideal descending speed is controlled and selected. The two structural forms for controlling the container to slowly fall can be adopted for the user to select.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms, and any person skilled in the art may use the above-mentioned technical contents to change or modify the equivalent embodiments into equivalent variations to apply to other fields, but all the modifications and equivalent variations that do not depart from the technical contents of the present invention are still within the scope of the present invention.

Claims (9)

1. The pneumatic control composite hydraulic reversing valve is characterized in that the pneumatic control composite hydraulic reversing valve (1) comprises an integral hydraulic reversing valve group, an oil inlet (28), an oil return port (34) and a pneumatic control assembly;

the integral hydraulic reversing valve group comprises three hydraulic reversing valves which are transversely arranged, wherein the three hydraulic reversing valves which are transversely arranged are respectively a primary reversing valve, a secondary reversing valve and a tertiary reversing valve;

the primary reversing valve comprises a first valve body and a first valve core (6), the first valve core (6) is arranged in a cavity of the first valve body, and the length direction of the first valve core (6) is parallel to the longitudinal direction of the first valve body; the two-stage reversing valve comprises a second valve body and a second valve core (9), the second valve core (9) is arranged in a cavity of the second valve body, and the length direction of the second valve core (9) is parallel to the longitudinal direction of the second valve body; the three-stage reversing valve comprises a third valve body and a third valve core (11), the third valve core (11) is arranged in a cavity of the third valve body, and the length direction of the third valve core (11) is parallel to the longitudinal direction of the third valve body;

the valve core I (6), the valve core II (9) and the valve core III (11) respectively comprise a plurality of middle shoulders, two end shoulders and a plurality of undercut grooves; the plurality of undercut grooves are respectively positioned between the adjacent shoulders;

the first valve body, the second valve body and the third valve body are transversely aligned and are sequentially transversely arranged into an integrated structure to form a main valve body of the pneumatic control composite hydraulic reversing valve (1), and two oil inlet passages are formed in the longitudinal middle parts of the first valve body, the second valve body and the third valve body;

the oil inlet (28) is formed in the two sides, far away from the valve body, of the first valve body, and the oil inlet (28) is communicated with two oil inlet passages in the first valve body, the second valve body and the third valve body;

when the pneumatic control composite hydraulic reversing valve (1) is in a non-working state, the two oil inlet passages are respectively communicated with the undercut grooves among the shoulders in the middle of the valve core I (6), the valve core II (9) and the valve core III (11);

a front transverse oil return passage (35) and a rear transverse oil return passage (36) are formed in a main valve body of the pneumatic control composite hydraulic reversing valve (1); when the pneumatic control composite hydraulic reversing valve (1) is in a non-working state, two end shoulders of the first valve core (6), the second valve core (9) and the third valve core (11) longitudinally penetrate through the front oil return channel (35) and the rear oil return channel (36) respectively, and can plug the front oil return channel (35) and the rear oil return channel (36);

the oil return port (34) is formed in the two sides, far away from the valve body, of the valve body III, an oil return passage L is formed between the valve body III and the valve body II, and the oil return passage L is communicated with the front oil return passage (35), the oil return port (34) and the rear oil return passage (36) respectively; the two oil inlet passages are communicated with an oil return opening (34) at the end away from the oil inlet (28);

the pneumatic control assembly comprises three cylinders, the three cylinders are respectively a cylinder I (21), a cylinder II (20) and a cylinder III (12), piston rods of the cylinder I (21), the cylinder II (20) and the cylinder III (12) are respectively and fixedly connected with the end parts of the valve core I (6), the valve core II (9) and the valve core III (11) in the length direction, and can drive the valve core I (6), the valve core II (9) and the valve core III (11) to move longitudinally;

the first valve body, the second valve body and the third valve body are respectively provided with oil ports, and the oil ports are respectively connected with oil ports of an external oil cylinder through pipelines; when the pneumatic control composite hydraulic reversing valve (1) is in a non-working state, oil ports of the first valve body, the second valve body and the third valve body respectively correspond to the undercut grooves adjacent to end shoulders of the first valve core (6), the second valve core (9) and the third valve core (11).

2. The pneumatic control composite hydraulic reversing valve according to claim 1, wherein the pneumatic control composite hydraulic reversing valve (1) is mounted on a dumper, two oil ports of the first valve body, the second valve body and the third valve body are respectively connected with a lifting oil cylinder (4), an environment-friendly cover opening and closing oil cylinder (3) and a tail plate switching oil cylinder (2), an oil pump outlet of a hydraulic system is connected with the oil inlet (28), and an oil return port (34) is communicated with a hydraulic oil tank (5) of the dumper.

3. The pneumatic control composite hydraulic reversing valve according to claim 2, wherein a lifting oil port (39) is formed in the first valve body, the lifting oil cylinder (4) is a single-acting oil cylinder with only one oil port, and the lifting oil port (39) is communicated with the oil port of the lifting oil cylinder (4);

the second valve body is provided with a cover closing oil port (30) and a cover opening oil port (31), and the cover closing oil port (30) and the cover opening oil port (31) are respectively communicated with the front oil port and the rear oil port of the environment-friendly cover opening and closing oil cylinder (3);

and the third valve body is provided with a tail plate oil port (33) and a tail plate oil port (32), and the tail plate oil port (33) and the tail plate oil port (32) are respectively communicated with the front oil port and the rear oil port of the tail plate switch oil cylinder (2).

4. The pneumatic control compound hydraulic directional valve according to any one of claims 1 to 3, wherein the cylinder III (12) further comprises a cylinder barrel III and a movable piston III (15); the two longitudinal ends of the cylinder barrel III are respectively provided with a fixed piston III (14) and a cylinder III rear cover (16), the movable piston III (15) is arranged at one end, away from the valve core III (11), of a piston rod of the cylinder III (12), and the movable piston III (15) is positioned in the cylinder barrel III and is matched with the cylinder barrel III; a tail plate air port (122) and a tail plate air port (121) are respectively formed in the cylinder barrel III close to the fixed piston III (14) and the cylinder III rear cover (16);

the second cylinder (20) further comprises a second cylinder barrel and a second movable piston (19); a fixed piston II (18) and a cylinder II rear cover are respectively arranged at the two longitudinal ends of the cylinder II, the movable piston II (19) is arranged at one end, away from the valve core II (9), of a piston rod of the cylinder II (20), and the movable piston II (19) is positioned in the cylinder II and is matched with the cylinder II; a cover closing air port (202) and a cover opening air port (201) are respectively formed in the cylinder barrel II close to the fixed piston II (18) and the rear cover of the cylinder barrel II;

the first cylinder (21) further comprises a first cylinder barrel and a first movable piston (23); the two longitudinal ends of the first cylinder barrel are respectively provided with a fixed piston I (22) and a cylinder I rear cover (26), the movable piston I (23) is installed at one end, away from the first valve core (6), of a piston rod of the cylinder I (21), and the movable piston I (23) is located in the first cylinder barrel and matched with the first cylinder barrel; and a descending air port (212) and a lifting air port (211) are respectively formed on the first cylinder barrel close to the first fixed piston (22) and the first cylinder rear cover (26).

5. The pneumatic control composite hydraulic reversing valve according to claim 4, characterized in that a slow-lowering piston (25) is further installed between the lifting air port (211) of the first cylinder (21) and the first cylinder rear cover (26), the slow-lowering piston (25) is matched with the first cylinder barrel of the first cylinder (21), the center of the end, close to the first cylinder rear cover (26), of the slow-lowering piston (25) is vertically and fixedly connected with an adjusting rod (24), the end, far away from the slow-lowering piston (25), of the adjusting rod (24) penetrates through the first cylinder rear cover (26), and the adjusting rod (24) is driven by the slow-lowering piston (25) to synchronously and longitudinally move along the first cylinder barrel; a slow-down air port (213) is arranged on the first rear cover (26) of the air cylinder.

6. The pneumatic control compound hydraulic directional valve according to claim 5, wherein the valve core I (6) comprises two middle shoulders, two end shoulders and three undercut grooves, the two middle shoulders are respectively a shoulder I (61) and a shoulder II (62), the two end shoulders are respectively a shoulder III (63) and a shoulder IV (64), and the three undercut grooves are respectively an undercut groove I (65), an undercut groove II (66) and an undercut groove III (67); the end of the shoulder IV (64) close to the undercut groove III (67) is provided with a slow-down notch H;

the second valve core (9) comprises three middle shoulders, two end shoulders and four undercut grooves, the three middle shoulders are a fifth shoulder (91), a sixth shoulder (95) and a seventh shoulder (92), the two end shoulders are a eighth shoulder (93) and a ninth shoulder (94), and the four undercut grooves are a fourth undercut groove (96), a fifth undercut groove (97), a sixth undercut groove (98) and a seventh undercut groove (99);

the third valve core (11) comprises three middle shoulders, two end shoulders and four undercut grooves, the three middle shoulders are respectively a tenth shoulder (111), a eleventh shoulder (115) and a twelfth shoulder (112), the two end shoulders are respectively a thirteenth shoulder (113) and a fourteenth shoulder (114), and the four undercut grooves are respectively an eighth undercut groove (116), a ninth undercut groove (117), a tenth undercut groove (118) and an eleventh undercut groove (119).

7. The pneumatic control composite hydraulic reversing valve according to claim 6, wherein the pneumatic control composite hydraulic reversing valve (1) further comprises a plurality of overflow valves, and the overflow valves are respectively a primary overflow valve (29), a secondary overflow valve (8) and a tertiary overflow valve (10);

the primary overflow valve (29) is installed on an oil inlet passage of the first valve body, the secondary overflow valve (8) is installed on an oil inlet passage K between the first valve body and the second valve body, and the tertiary overflow valve (10) is installed on an oil inlet passage K2 between the third valve body and the second valve body.

8. The pneumatic control composite hydraulic reversing valve according to claim 6, wherein flow control valves (38) are arranged in the front oil return channel (35) between the first valve body and the second valve body and in the front oil return channel (35) between the third valve body and the second valve body.

9. The pneumatic control compound hydraulic directional valve according to claim 1, wherein the ends of the first valve core (6), the second valve core (9) and the third valve core (11) far away from the cylinder assembly are all provided with a ventilation cover (7).

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