CN207583714U - A kind of multi-cylinder linkage hydraulic system of hydraulic machine - Google Patents

Abstract

The utility model discloses a kind of multi-cylinder linkage hydraulic system of hydraulic machine, belong to hydraulic press technical field.It include for control master cylinder action master cylinder control section；Master cylinder control section includes inserted valve III, inserted valve IV, two-position four-way solenoid valve II, shuttle valve I, two-position four-way solenoid valve III, inserted valve V, overflow valve IV, overflow valve V, two-position four-way solenoid valve IV, inserted valve VII, two-position three way magnetic valve I, inserted valve Ⅸ and two-position three way magnetic valve II, two-position four-way solenoid valve II controls inserted valve III, two-position four-way solenoid valve III controls inserted valve IV, two-position four-way solenoid valve IV controls inserted valve V, two-position three way magnetic valve I controls inserted valve VII, and two-position three way magnetic valve II controls inserted valve Ⅸ.The utility model can cause hydraulic press, and when large-scale workpiece suppresses bending, system pressure is reliable and stable, and line shock load is relatively small, is conducive to extend the service life of the hydraulic units such as oil cylinder, pipeline.

Description

A kind of multi-cylinder linkage hydraulic system of hydraulic machine

Technical field

The utility model belongs to hydraulic press technical field, is related to a kind of hydraulic control system of the hydraulic press of thousands of tonnages, More specifically to a kind of multi-cylinder linkage hydraulic system of hydraulic machine.

Background technology

Hydraulic press is a kind of important molding equipment, generates highly pressurised liquid by motor drive hydraulic pump, passes through hydraulic cylinder Generate linear motion work, since hydraulic press flexibility (adaptability) of operation is wide, be therefore widely used in metal and it is nonmetallic into Type processes occasion.

According to the number of column, hydraulic press can be divided into：Open side type (c-type), queen post, four-column type etc..Wherein, four column liquid Press is more common, it is a kind of static pressure using oil pump conveying hydraulic oil to process metal, plastics, rubber, timber, powder Wait the mechanical equipment of products.It is usually used in pressing process and block pressing forming process, such as：Forging and stamping, punching press, cold-extruded, alignment, bending, Flange, process of sheet drawing, powder metallurgy, press fitting etc..Specifically include upper beam, pedestal, the work between upper beam and pedestal Dynamic crossbeam and the four columns for connecting upper beam and pedestal, four-column hydraulic press are treated rapidoprint by moved cross beam and are pressed System, in compacting, moved cross beam is slided along four columns.With the development of technology, for the workpiece using hydraulic press compacting Also increasingly tend to integration and enlargement, such as the pressing operation of crossbeams many on automobile, this requires hydraulic press to have bigger Working diameter and higher press power.

Designed before this for above-mentioned requirements the applicant and applied one it is entitled：A kind of large-tonnage long span multi-cylinder connection Electrical automobile longeron compression moulding hydraulic press, application No. is：201720545948.4 utility model patent, meet large parts Bending pressing operation.This mainly includes workbench, upper beam and sliding block；The sliding block is arranged between workbench and upper beam Column on, pass through the hydraulic oil cylinder driving being mounted on upper beam；The column has 10, five groups is divided into, along workbench Length direction is arranged at intervals, and every group of two root posts are separately positioned on the both ends of workbench width direction；The workbench is equipped with It through the ejection hole of its upper and lower surface, ejects and liftout tank is installed in hole, liftout tank is connected with angled slide block.The program is vertical by increasing Column number and improving driving force mode so that hydraulic press disclosure satisfy that large-scale workpiece, and tonnage has reached 1650 tons or so, and And the hydraulic press also further solves the problems, such as that pressed molded part is not easy to remove.But have the problem of new again thereupon, Namely so huge hydraulic press, the volume of operating cylinder are also very huge, it is desirable that hydraulic coupling it is also quite big, so to whole The design requirement of a hydraulic system is very high, the hydraulic system on existing general small hydraulic machine is used before applicant, only It is simple to improve operating oil pressure, although bending work can be completed reluctantly, in operating process, often occur system pressure fluctuation compared with Greatly, a series of problems, such as equipment abnormal sound, pipeline shake is big, and the component lifes such as frequent oil leak and oil cylinder, pipeline are short, and to whole The control of a bending operation is not easy, and increases the difficulty of large-scale workpiece bending operation, and safety is not also high.

Also there are other similar hydraulic presses in the prior art, for example, Chinese Patent Application No. is：201210038872.8 Publication date is：The patent document on December 17th, 2014 discloses a kind of four column hydraulic forging presses, and by column, upper, middle and lower are horizontal Beam, operating cylinder and backhaul oil cylinder are formed；Guide pillar structure is equipped between middle cross beam and column, its main feature is that：Guide pillar Structure includes four groups of guidance sets being made of guide plate and wedge, and wedge is by pressing plate pressing in middle cross beam；Guide plate is close to upper The position at end is equipped with support plate, and adjusting pad is equipped between support plate and pressing plate；The lower end of operating cylinder plunger rod is formed with cylinder Chamber, is equipped with the first ball ring and spherical surface column in cylindrical cavity, and spherical surface column outer cover is equipped with supporting sleeve, on the lower end lug boss of supporting sleeve It is rack-mounted to have supporting structure, cushion is equipped between supporting structure and lug boss；Second spherical surface is installed inside the lower end of supporting sleeve Pad.Although the hydraulic press volume of this scheme is also huge, kiloton is not exceeded generally, usually reaches six or more just in column It is possible that therefore its use general hydraulic system that can meet operational requirements, and it does not provide corresponding hydraulic system yet.

In conclusion for being more than requirements at the higher level of the hydraulic press more than kiloton to hydraulic system, it is necessary to which design is a kind of The hydraulic system of hydraulic machine of such high pressure working environment is can adapt to, this is also purpose of the present invention place.

Utility model content

1st, it to solve the problems, such as

The utility model provides a kind of multi-cylinder linkage hydraulic system of hydraulic machine, and its object is to solve existing hydraulic system not The problem of being well positioned to meet the bending operation more than kiloton more than hydraulic press.The hydraulic system is directed to more than kiloton tonnage liquid Press specially designs, and optimizes the connection relation of each hydraulic unit so that when large-scale workpiece suppresses bending, system pressure is stablized Reliably, line shock load is relatively small, is conducive to extend the service life of the hydraulic units such as oil cylinder, pipeline；It can adapt to Tonnage is in 1650 tons and the bending operation of above hydraulic press.

The utility model also provides the application method of above-mentioned multi-cylinder linkage hydraulic system of hydraulic machine, and the realization that can stablize is fast Under, it is slow under, pressurize, the actions such as release and backhaul, and workpiece after processing can be ejected, so as to which workpiece be facilitated to remove.

2nd, technical solution

To solve the above problems, the utility model adopts the following technical scheme.

A kind of multi-cylinder linkage hydraulic system of hydraulic machine, including oil-feeding control part and master cylinder control section, oil-feeding control For providing hydraulic oil needed for system work, the master cylinder control section is used to control the action of master cylinder for part；

The master cylinder control section includes inserted valve III, inserted valve IV, two-position four-way solenoid valve II, shuttle valve I, two four Three-way electromagnetic valve III, inserted valve V, overflow valve IV, overflow valve V, two-position four-way solenoid valve IV, inserted valve VII, two-position three-way electromagnetic Valve I, inserted valve Ⅸ and two-position three way magnetic valve II；

The oil inlet of the inserted valve III and inserted valve IV is all connected with the pressure oil of oil-feeding control part, and inserted valve III goes out Hydraulic fluid port connects the epicoele of master cylinder, and the oil outlet of inserted valve IV connects the oil inlet of inserted valve V and inserted valve VII, and inserted valve V goes out Hydraulic fluid port connected tank, the oil outlet of inserted valve VII connect the cavity of resorption of master cylinder；

The two-position four-way solenoid valve II, the P mouths of two-position four-way solenoid valve III and the T mouthfuls of pressures for connecing oil-feeding control part respectively Power oil and fuel tank, the A mouths of two-position four-way solenoid valve II connect the control port of inserted valve III, and the A mouths of two-position four-way solenoid valve III connect The B mouths of one oil inlet of shuttle valve I, two-position four-way solenoid valve II and two-position four-way solenoid valve III are turned off, shuttle valve I another Oil inlet connects the oil outlet of inserted valve IV, and the oil outlet of shuttle valve I connects the control port of inserted valve IV；

The T mouths of the oil inlet of the overflow valve IV, the oil inlet of overflow valve V and two-position four-way solenoid valve IV patch dress The control port of valve V, the oil outlet connected tank of overflow valve V, the oil outlet of overflow valve IV meet the B of two-position four-way solenoid valve IV Mouthful, the P mouth connected tanks of two-position four-way solenoid valve IV, the A mouths cut-off of two-position four-way solenoid valve IV；

The A mouths of the two-position three way magnetic valve I connect the control port of inserted valve VII, and the P mouths of two-position three way magnetic valve I patch Fill the oil outlet of valve VII, the T mouth connected tanks of two-position three way magnetic valve I；

The oil inlet of the inserted valve Ⅸ connects the epicoele of master cylinder, the oil outlet connected tank of inserted valve Ⅸ；Described two three The P mouths of three-way electromagnetic valve II connect the oil inlet of inserted valve Ⅸ, the T mouth connected tanks of two-position three way magnetic valve II, two-position three way magnetic valve II A mouths connect the control port of inserted valve Ⅸ.

As a further improvement, the master cylinder control section further includes inserted valve VI and two-position four-way solenoid valve V；Institute The oil inlet for stating inserted valve VI connects the oil outlet of inserted valve IV, the oil outlet connected tank of inserted valve VI, the control oil of inserted valve VI Mouth connects the A mouths of the two-position four-way solenoid valve V, and the P mouths of two-position four-way solenoid valve V connect the oil inlet of inserted valve VI, two four The T mouth connected tanks of three-way electromagnetic valve V, the B mouths cut-off of two-position four-way solenoid valve V.

As a further improvement, it is connected to overflow valve VI between the cavity of resorption and fuel tank of the master cylinder.

As a further improvement, the master cylinder control section further includes inserted valve VIII, inserted valve Ⅹ and overflow valve VII；Institute It states inserted valve VIII to be connected between the oil outlet of inserted valve III and the epicoele of master cylinder, the oil inlet of inserted valve VIII connects inserted valve III Oil outlet, the oil outlet of inserted valve VIII are connected with control port, and connect the epicoele of master cylinder；Ⅹ oil inlet of inserted valve connects The oil outlet of inserted valve III, the oil outlet connected tank of inserted valve Ⅹ, overflow valve VII are connected on control port and the fuel tank of inserted valve Ⅹ Between, the also external control oil of control port of inserted valve Ⅹ.

As a further improvement, the master cylinder control section further includes two-position four-way solenoid valve VI and hydraulic control one-way valve, The P mouths of two-position four-way solenoid valve VI connect the pressure oil of oil-feeding control part, the T mouth connected tanks of two-position four-way solenoid valve VI, two The A mouths cut-off of four way solenoid valve VI, the B mouths of two-position four-way solenoid valve VI connect the control port of the hydraulic control one-way valve, hydraulic control list To the oil inlet connected tank of valve, the oil outlet of hydraulic control one-way valve connects the epicoele of master cylinder.

As a further improvement, further include liftout tank control section；The liftout tank control section includes inserted valve Ⅺ, three Position four-way solenoid valve II, inserted valve Ⅻ, shuttle valve II, inserted valve A, inserted valve B, check valve I, check valve II and check valve III；

The oil inlet of the inserted valve Ⅺ and inserted valve Ⅻ connects the pressure oil of oil-feeding control part, inserted valve Ⅺ it is fuel-displaced Mouth connects the epicoele of liftout tank, and the oil outlet of inserted valve Ⅻ connects the cavity of resorption of liftout tank；

The P mouths of the three position four-way electromagnetic valve II connect the pressure oil of oil-feeding control part, the T mouths of three position four-way electromagnetic valve II Connected tank, the A mouths of three position four-way electromagnetic valve II connect the control port of inserted valve Ⅺ, and the B mouths of three position four-way electromagnetic valve II connect shuttle valve II 1 oil inlets and check valve II export, another oil inlet of shuttle valve II connects Ⅻ oil outlet of inserted valve, and II oil outlet of shuttle valve connects The control port of inserted valve Ⅻ；

The oil inlet of the inserted valve B and the oil outlet of check valve I connect the epicoele of liftout tank, the oil outlet of inserted valve B With the equal connected tank of oil inlet of check valve I, the control port of inserted valve B connects the oil inlet of check valve II；

The oil inlet of the inserted valve A connects the cavity of resorption of liftout tank, the oil outlet connected tank of inserted valve A, the control of inserted valve A Hydraulic fluid port connects the oil inlet of check valve III, and the oil outlet of check valve III connects the control port of inserted valve Ⅺ.

As a further improvement, overflow valve Ⅸ is connected between the control port of the inserted valve A and fuel tank, inserted valve A's The also external control oil of control port.

As a further improvement, overflow valve Ⅹ is connected between the control port of the inserted valve B and fuel tank.

As a further improvement, the oil-feeding control part have it is one or more groups of, every group include oil pump, I and of inserted valve Inserted valve II；

The oil inlet connected tank of one or more groups of middle oil pumps, the oil outlet of oil pump connect I oil inlet of inserted valve；It is described to insert The oil outlet of dress valve I is connected with control port, provides pressure oil；The oil inlet of the inserted valve II connects the oil outlet of oil pump, inserts The oil outlet connected tank of valve II is filled, the control port of inserted valve II connects the B mouths of two-position four-way solenoid valve I, two-position four-way solenoid valve I P mouths and A mouthful end, the T mouth connected tanks of two-position four-way solenoid valve I；The overflow valve I be connected on the control port of inserted valve II with Between fuel tank.

As a further improvement, the control port for wherein having the inserted valve II of one group of oil-feeding control part connects overflow valve II The P mouths of oil inlet, the oil inlet of overflow valve III and three position four-way electromagnetic valve I, the oil outlet of overflow valve II connect 3-position 4-way electromagnetism The B mouths of valve I, the oil outlet of overflow valve III and the equal connected tank of T mouths of three position four-way electromagnetic valve I, the A mouths of three position four-way electromagnetic valve I Cut-off.3rd, advantageous effect

Compared with the prior art, the beneficial effects of the utility model are：

(1) the utility model multi-cylinder linkage hydraulic system of hydraulic machine is to be directed to specially to set more than kiloton tonnage hydraulic Meter, mainly by using the combination of inserted valve and solenoid valve, reaches the orderly reliable control to master cylinder and liftout tank so that liquid For press when large-scale workpiece suppresses bending, system pressure is reliable and stable, and line shock load is relatively small, is conducive to extend oil The service life of the hydraulic units such as cylinder, pipeline；Especially it can adapt to tonnage in 1650 tons and the compacting folding of above hydraulic press Curved operation can provide reference standard for the hydraulic control of six column more than large hydraulic press.

(2) the utility model multi-cylinder linkage hydraulic system of hydraulic machine, mainly by oil-feeding control part, master cylinder control section It is formed with liftout tank control section three parts, it is a variety of that oil-feeding control part can provide high pressure, low pressure and pressure release etc. according to action Pressure demand；Then mainly the sliding block of control master cylinder driving hydraulic press moves up and down for master cylinder control section, completes compacting bending Operation, can reliablely and stablely realize it is fast under, it is slow under, pressurize, the operation acts such as release and backhaul, meet bending demand；Ejection Then mainly to processing aftershaping workpiece ejection die, conveniently remove large-scale workpiece in cylinder control section.

(3) the utility model multi-cylinder linkage hydraulic system of hydraulic machine, master cylinder and liftout tank are respectively provided with safety valve, prevent work It overloads, plays a protective role to oil cylinder；Meanwhile master cylinder and liftout tank also set up charging loop, prevent pipe-line system It vacuumizes, plays a protective role to system pipeline and valve, be also beneficial to reduce vibrations and noise.

(4) the utility model multi-cylinder linkage hydraulic system of hydraulic machine, the utility model multi-cylinder linkage hydraulic system of hydraulic machine Application method, under the realization that can stablize is fast, it is slow under, pressurize, some row action such as release and backhaul, and also be able to process Workpiece ejects afterwards, so as to which workpiece be facilitated to remove.

Description of the drawings

Fig. 1 is the structure diagram of multi-cylinder linkage hydraulic press；

Fig. 2 is the hydraulic schematic diagram of the utility model multi-cylinder linkage hydraulic system of hydraulic machine；

Fig. 3 is the hydraulic schematic diagram of oil-feeding control part in Fig. 2；

Fig. 4 is the hydraulic schematic diagram of master cylinder control section in Fig. 2；

Fig. 5 is the hydraulic schematic diagram of liftout tank control section in Fig. 2.

Label in attached drawing is expressed as：

100th, oil-feeding control part；101st, oil pump；102nd, inserted valve I；103rd, inserted valve II；104th, overflow valve I；105th, two Position four-way solenoid valve I；106th, overflow valve II；107th, overflow valve III；108th, three position four-way electromagnetic valve I；

200th, master cylinder control section；201st, inserted valve III；202nd, inserted valve IV；203rd, two-position four-way solenoid valve II； 204th, shuttle valve I；205th, two-position four-way solenoid valve III；206th, inserted valve V；207th, overflow valve IV；208th, overflow valve V；209th, two Position four-way solenoid valve IV；210th, inserted valve VI；211st, two-position four-way solenoid valve V；212nd, inserted valve VII；213rd, two-position three way electricity Magnet valve I；214th, overflow valve VI；215th, master cylinder；216th, inserted valve VIII；217th, inserted valve Ⅸ；218th, two-position three way magnetic valve II； 219th, inserted valve Ⅹ；220th, overflow valve VII；221st, two-position four-way solenoid valve VI；222nd, hydraulic control one-way valve；

300th, liftout tank control section；301st, inserted valve Ⅺ；302nd, three position four-way electromagnetic valve II；303rd, inserted valve Ⅻ； 304th, shuttle valve II；305th, inserted valve A；306th, overflow valve Ⅸ；307th, liftout tank；308th, inserted valve B；309th, check valve I；310th, it is single To valve II；311st, overflow valve Ⅹ；312nd, check valve III.

Specific embodiment

The utility model is further described below with reference to specific embodiments and the drawings.

Embodiment 1

A kind of multi-cylinder linkage hydraulic system of hydraulic machine of the present embodiment is mainly used for the large hydraulic press more than kiloton tonnage Control, that is, apply in general to hydraulic presses more than six columns.For example, one applied before the applicant is entitled：One Kind large-tonnage long span multi-cylinder linkage automobile longitudinal girder compression moulding hydraulic press, application No. is：201720545948.4 practicality it is new Type patent, for structure as shown in Figure 1, with 10 columns, tonnage reaches 1650 tons, and so huge hydraulic press needs 4 masters Oil cylinder 215 drive sliding block drive mold move up and down along column, complete to the workpiece in lower mold fixed on workbench into Row bending operation, the requirement to hydraulic system are relatively high；And the hydraulic system structure on existing general hydraulic press is used, only It is simple raising operating oil pressure, although compression moulding work can be completed reluctantly, in operating process, system pressure wave often occurs A series of problems, such as dynamic larger, equipment abnormal sound, pipeline shake is big, and the component lifes such as frequent oil leak and oil cylinder, pipeline are short, and The control of entire pressing operation is not easy, increases the difficulty of large-scale workpiece pressing operation, safety is not also high.In addition, large-scale work Part also is difficult to remove from mold after pressing, and liftout tank 307 is increased in the lower part of workbench in said program, to solve this Problem, thus also will be according to the action of pressing operation demand control liftout tank 307.Therefore, on the basis of said program, this reality It applies example and devises hydraulic system suitable for such great tonnage hydraulic machine, the structure composition of the hydraulic system is carried out below detailed Explanation.

As shown in Fig. 2, the multi-cylinder linkage hydraulic system of hydraulic machine is mainly by oil-feeding control part 100, master cylinder control unit Divide 200 and 300 three parts of liftout tank control section composition.Wherein, oil-feeding control part 100 is power section, provides system Hydraulic oil needed for work meets the pressure demand of master cylinder control section 200 and liftout tank control section 300；Master cylinder controls Part 200 is used to control the action of master cylinder 215, realize it is fast under, it is slow under, pressurize, the action controls such as release and backhaul；And it ejects Cylinder control section 300 is then the action for controlling liftout tank 307, completes ejection and the retraction operation of liftout tank 307.

With reference to shown in Fig. 2 and Fig. 3, oil-feeding control part 100 uses multigroup use arranged side by side, that is, using multiple oil pumps 101 carry out fuel feeding, three groups are used in the present embodiment, every group includes oil pump 101, inserted valve I 102 and inserted valve II 103.Its In, there is the oil inlet connected tank of two groups of oil pump 101 in oil-feeding control part 100, the oil outlet of oil pump 101 connects inserted valve I 102 Oil inlet；The oil outlet of the inserted valve I 102 of later group is connected with control port, and connects the oil inlet of previous group inserted valve I 102, Pressure oil is provided.And the oil inlet of inserted valve II 103 connects the oil outlet of oil pump 101, the oil outlet connected tank of inserted valve II 103, The control port of inserted valve II 103 connects the B mouths of two-position four-way solenoid valve I 105, and the P mouths of two-position four-way solenoid valve I 105 and A mouthfuls are cut Only, the T mouth connected tanks of two-position four-way solenoid valve I 105；Overflow valve I 104 be connected on the control port of inserted valve II 103 and fuel tank it Between.

In addition also have one group of oil-feeding control part 100, equally, the oil inlet connected tank of oil pump 101, oil pump 101 it is fuel-displaced Mouthful connect I 102 oil inlet of inserted valve, behind two groups of the oil outlet of oil outlet and this group of inserted valve I 102 of inserted valve I 102 connect It is logical, and the oil outlet of this group of inserted valve I 102 is connected to by pipeline, master cylinder control section 200 and liftout tank control section 300, provide pressure oil for them.However, the control port of inserted valve II 103 connects the oil inlet of overflow valve II 106, overflows in the group The oil inlet of valve III 107 and the P mouths of three position four-way electromagnetic valve I 108 are flowed, the oil outlet of overflow valve II 106 connects 3-position 4-way electromagnetism The B mouths of valve I 108, the oil outlet of overflow valve III 107 and the equal connected tank of T mouths of three position four-way electromagnetic valve I 108,3-position 4-way electromagnetism The A mouths cut-off of valve I 108.The Median Function of three position four-way electromagnetic valve I 108 is H-type, during in middle position, each hydraulic fluid port intercommunication；Overflow The oil pressure relief of valve III 107 is more than the oil pressure relief of overflow valve II 106, so as to control three position four-way electromagnetic valve I 108 available not Same charge oil pressure plays a significant role in the pressure release control of master cylinder 215.

With reference to shown in Fig. 2 and Fig. 5, master cylinder control section 200 includes inserted valve III 201, inserted valve IV 202, two four Three-way electromagnetic valve II 203, shuttle valve I 204, two-position four-way solenoid valve III 205, inserted valve V 206, overflow valve IV 207, overflow valve V 208th, two-position four-way solenoid valve IV 209, inserted valve VI 210, two-position four-way solenoid valve V 211, inserted valve VII 212, two-position three way Solenoid valve I 213, inserted valve VIII 216, inserted valve Ⅸ 217, two-position three way magnetic valve II 218, inserted valve Ⅹ 219, overflow valve VII 220th, two-position four-way solenoid valve VI 221 and hydraulic control one-way valve 222.

Wherein, the oil inlet of inserted valve III 201 and inserted valve IV 202 is all connected with the pressure oil of oil-feeding control part 100, inserts The oil outlet of dress valve III 201 connects the epicoele of master cylinder 215, and the oil outlet of inserted valve IV 202 connects inserted valve V 206 and inserted valve VII 212 oil inlet, the oil outlet connected tank of inserted valve V 206, the oil outlet of inserted valve VII 212 connect the cavity of resorption of master cylinder 215；It is main Overflow valve VI 214 is connected between the cavity of resorption and fuel tank of oil cylinder 215, the pressure overload of master cylinder 215 can be prevented, protection is played and makees With.

Two-position four-way solenoid valve II 203, the P mouths of two-position four-way solenoid valve III 205 and T mouthfuls connect oil-feeding control part respectively 100 pressure oil and fuel tank, the A mouths of two-position four-way solenoid valve II 203 connect the control port of inserted valve III 201, two-position four-way electricity The A mouths of magnet valve III 205 connect an oil inlet of shuttle valve I 204, two-position four-way solenoid valve II 203 and two-position four-way solenoid valve III 205 B mouths be turned off, another oil inlet of shuttle valve I 204 connects the oil outlet of inserted valve IV 202, and the oil outlet of shuttle valve I 204 patches Fill the control port of valve IV 202.

The T mouths of the oil inlet of overflow valve IV 207, the oil inlet of overflow valve V 208 and two-position four-way solenoid valve IV 209 connect The control port of inserted valve V 206, the oil outlet connected tank of overflow valve V 208, the oil outlet of overflow valve IV 207 connect two-position four-way The B mouths of solenoid valve IV 209, the P mouth connected tanks of two-position four-way solenoid valve IV 209, the A mouths cut-off of two-position four-way solenoid valve IV 209. Herein, inserted valve V 206 is controlled by V 208 two overflow valves of overflow valve IV 207 and overflow valve, passes through two-position four-way solenoid valve IV 209 switch over, and overflow valve IV 207 is different with the Opening pressure of overflow valve V 208, and the Opening pressure of overflow valve IV 207 is small In the Opening pressure of overflow valve V 208, so as to obtain different V 206 Opening pressures of inserted valve, different master cylinders 215 is controlled Downstream rate.

The A mouths of two-position three way magnetic valve I 213 meet the control port of inserted valve VII 212, the P of two-position three way magnetic valve I 213 Mouth connects the oil outlet of inserted valve VII 212, the T mouth connected tanks of two-position three way magnetic valve I 213.

The oil inlet of inserted valve Ⅸ 217 connects the epicoele of master cylinder 215, the oil outlet connected tank of inserted valve Ⅸ 217；Described two The P mouths of position-3-way solenoid valve II 218 connect the oil inlet of inserted valve Ⅸ 217, the T mouth connected tanks of two-position three way magnetic valve II 218, and two The A mouths of position-3-way solenoid valve II 218 connect the control port of inserted valve Ⅸ 217.Two-position three way magnetic valve II 218 controls inserted valve Ⅸ The oil return of 215 epicoele of master cylinder is realized in 217 keying.

The oil inlet of inserted valve VI 210 connects the oil outlet of inserted valve IV 202, and the oil outlet connected tank of inserted valve VI 210 is inserted The control port of dress valve VI 210 connects the A mouths of the two-position four-way solenoid valve V 211, and the P mouths of two-position four-way solenoid valve V 211 connect The oil inlet of inserted valve VI 210, the T mouth connected tanks of two-position four-way solenoid valve V 211, the B mouths of two-position four-way solenoid valve V 211 are cut Only.Two-position four-way solenoid valve V 211 controls the keying of inserted valve VI 210, can realize the fast downlink of workpiece compacting front-slider, Shorten downgoing time, improve working efficiency.

Inserted valve VIII 216 is connected between the oil outlet of inserted valve III 201 and the epicoele of master cylinder 215, inserted valve VIII 216 Oil inlet connects the oil outlet of inserted valve III 201, and the oil outlet of inserted valve VIII 216 is connected with control port, and connects master cylinder 215 Epicoele；Ⅹ 219 oil inlet of inserted valve connects the oil outlet of inserted valve III 201, the oil outlet connected tank of inserted valve Ⅹ 219, Overflow valve VII 220 is connected between control port and the fuel tank of inserted valve Ⅹ 219, the also external control of control port of inserted valve Ⅹ 219 Liquefaction.Inserted valve VIII 216 is that can prevent 215 epicoele oil return of master cylinder in system pressurize, and inserted valve Ⅹ 219 coordinates overflow valve VII 220 can prevent in pressing process, 215 upper cavity pressure of master cylinder overload, and can far be controlled by external control oil.

The P mouths of two-position four-way solenoid valve VI 221 connect the pressure oil of oil-feeding control part 100, two-position four-way solenoid valve VI 221 T mouth connected tanks, the A mouths cut-off of two-position four-way solenoid valve VI 221, the B mouths of two-position four-way solenoid valve VI 221 connect the hydraulic control list Control port to valve 222, the oil inlet connected tank of hydraulic control one-way valve 222, the oil outlet of hydraulic control one-way valve 222 connect master cylinder 215 epicoele.The keying of VI 221 controllable hydraulic control one-way valve 222 of two-position four-way solenoid valve, as needed for master cylinder 215 Epicoele supplements fluid, prevents pipe-line system from vacuumizing, all plays a protective role to system pipeline, valve and oil cylinder, also favorably In reduction vibrations and noise.

With reference to shown in Fig. 2 and Fig. 4, liftout tank control section 300 includes inserted valve Ⅺ 301, three position four-way electromagnetic valve II 302nd, inserted valve Ⅻ 303, shuttle valve II 304, inserted valve A305, inserted valve B308, check valve I 309, check valve II 310 and unidirectional Valve III 312.

Wherein, the oil inlet of inserted valve Ⅺ 301 and inserted valve Ⅻ 303 connects the pressure oil of oil-feeding control part 100, inserting The oil outlet of valve Ⅺ 301 connects the epicoele of liftout tank 307, and the oil outlet of inserted valve Ⅻ 303 connects the cavity of resorption of liftout tank 307.Three four The P mouths of three-way electromagnetic valve II 302 connect the pressure oil of oil-feeding control part 100, the T mouth connected tanks of three position four-way electromagnetic valve II 302, and three The A mouths of position four-way solenoid valve II 302 connect the control port of inserted valve Ⅺ 301, and the B mouths of three position four-way electromagnetic valve II 302 connect shuttle valve II 304 1 oil inlets and check valve II 310 export, another oil inlet of shuttle valve II 304 connects Ⅻ 303 oil outlet of inserted valve, shuttle II 304 oil outlet of valve connects the control port of inserted valve Ⅻ 303.Herein, II 302 Median Function of three position four-way electromagnetic valve is Y types, is located When middle position, P mouthfuls, A mouthfuls connect with B mouthfuls, T mouthfuls of connected tanks；Meanwhile connect a list before the P mouths of three position four-way electromagnetic valve II 302 To valve Ⅸ, oil reflux in three position four-way electromagnetic valve II 302 is prevented.Three position four-way electromagnetic valve II 302 is used to control inserted valve Ⅺ 301 With the keying of inserted valve Ⅻ 303, so as to control the hydraulic oil direction into liftout tank 307, its upper and lower cavity is made to replace oil inlet.

The oil inlet of inserted valve B308 and the oil outlet of check valve I 309 meet the epicoele of liftout tank 307, inserted valve B308 Oil outlet and check valve I 309 the equal connected tank of oil inlet, the control port of inserted valve B308 connects the oil inlet of check valve II 310 Mouthful.The oil inlet of inserted valve A305 connects the cavity of resorption of liftout tank 307, the oil outlet connected tank of inserted valve A305, inserted valve A305's Control port connects the oil inlet of check valve III 312, and the oil outlet of check valve III 312 connects the control port of inserted valve Ⅺ 301.Separately Outside, overflow valve Ⅸ 306, the also external control of control port of inserted valve A305 are connected between the control port of inserted valve A305 and fuel tank Overflow valve Ⅹ 311 is connected between the control port of liquefaction and inserted valve B308 and fuel tank.Here, inserted valve A305 is used as the back of the body Pressure valve is opened when liftout tank 307 is retracted, cavity of resorption oil return, and is passed through overflow valve Ⅸ 306 and adjusted opening pressure；And inserted valve B308 is then opened when liftout tank 307 ejects, epicoele oil return, and is passed through overflow valve Ⅹ 311 and controlled Opening pressure；Check valve I 309 Epicoele hydraulic oil can be supplemented when liftout tank 307 is retracted, prevents from vacuumizing.

From the foregoing, it will be observed that oil-feeding control part 100 can be more according to action offer high pressure, low pressure and pressure release etc. in the hydraulic system Kind pressure demand；Then mainly control master cylinder 215 drives the sliding block of hydraulic press to move up and down for master cylinder control section 200, completes Pressing operation, can reliablely and stablely realize it is fast under, it is slow under, pressurize, the operation acts such as release and backhaul, meet bending demand； Then mainly to processing aftershaping workpiece ejection die, conveniently remove large-scale workpiece in liftout tank control section 300.

The hydraulic system is to be directed to specially to design more than kiloton tonnage hydraulic, mainly by using inserted valve and electromagnetism The combination of valve reaches the orderly reliable control to master cylinder 215 and liftout tank 307 so that hydraulic press when large-scale workpiece is suppressed, System pressure is reliable and stable, and line shock load is relatively small, and be conducive to the hydraulic units such as extension oil cylinder, pipeline uses the longevity Life；Especially it can adapt to tonnage in 1650 tons and the bending operation of above hydraulic press, can be six column more than large hydraulic press Hydraulic control provide reference standard.

Embodiment 2

The application method of a kind of multi-cylinder linkage hydraulic system of hydraulic machine of the present embodiment, by the hydraulic pressure for controlling embodiment 1 In system respectively pump, valve and oil cylinder realize master cylinder 215 it is fast under, it is slow under, release and the top of backhaul action and liftout tank 307 Go out and retract action.

In the present embodiment, the electromagnet of first two groups of two-position four-way solenoid valve I 105 is remembered respectively in oil-feeding control part 100 For YV1 and YV2, the electromagnet of I 108 left and right sides of three position four-way electromagnetic valve of later group is denoted as YV3 and YV4；Master cylinder controls Two-position four-way solenoid valve II 203, two-position four-way solenoid valve III 205, two-position three way magnetic valve I 213, two-position four-way in part 200 Solenoid valve V 211, two-position four-way solenoid valve IV 209, two-position three way magnetic valve II 218 and two-position four-way solenoid valve VI 221 electricity Magnet is denoted as YV5, YV6, YV7, YV8, YV9, YV10 and YV11 respectively；Three position four-way electromagnetic valve in liftout tank control section 300 The solenoid valve of II 302 left and right sides is denoted as YV13 and YV12, so as to the explanation to subsequent action.Each action is described in detail below Realize step.

First, under master cylinder is fast

Electromagnet YV1, YV2, YV3, YV5, YV7 and YV8 obtain it is electric, remaining electromagnet must not electricity, oil pump 101 export hydraulic pressure Oil enters master cylinder control section 200 through inserted valve I 102；Two-position four-way solenoid valve II 203 is controlled in master cylinder control section 200 Fuel tank is connected in the control port of inserted valve III 201 processed, and inserted valve III 201 is opened under pressure oil effect, two-position four-way solenoid valve III 205 control inserted valve IV 202 to close under pressure oil effect, and pressure oil enters the upper of master cylinder 215 through inserted valve VIII 216 Chamber；Two-position three way magnetic valve I 213 controls the control port connected tank of inserted valve VII 212, and two-position four-way solenoid valve V 211 controls The control port connected tank of inserted valve VI 210, under the hydraulic oil effect of 215 cavity of resorption of master cylinder, inserted valve VII 212 and inserted valve VI 210 open, and the hydraulic oil of 215 cavity of resorption of master cylinder flows back to fuel tank, realize the fast downlink action of master cylinder 215.

2nd, under master cylinder is slow

Electromagnet YV1, YV2, YV3, YV5, YV7 and YV9 obtain it is electric, remaining electromagnet must not electricity, oil pump 101 export hydraulic pressure Oil enters master cylinder control section 200 through inserted valve I 102, and system establishes pressure；In 215 epicoele of master cylinder pressure oil with it is above-mentioned Master cylinder flows to identical when acting down soon；And for the cavity of resorption of master cylinder 215, two-position three way magnetic valve I 213 controls inserted valve VII 212 control port connected tank, two-position four-way solenoid valve IV 209 control the control port for making inserted valve V 206 through overflow valve IV 207 access fuel tanks, the epicoele of master cylinder 215 generate certain back pressure, under the hydraulic oil effect of 215 cavity of resorption of master cylinder, inserting Valve VII 212 and inserted valve V 206 are opened, and the hydraulic oil of 215 cavity of resorption of master cylinder flows back to fuel tank through overflow valve IV 207, realizes main oil The action of downlink at a slow speed of cylinder 215, carries out pressing operation.

3rd, master cylinder pressurize

Whole electromagnet dead electricity, the control port connected tank of inserted valve II 103, the hydraulic oil that oil pump 101 exports drive slotting It fills valve II 103 to open, pressure oil flows back to fuel tank, and no pressure is oily in system；And inserted valve VII 212 in master cylinder control section 200 It is closed with inserted valve VIII 216, the upper and lower cavity oil circuit of master cylinder 215 disconnects, and position is locked, and realizes the pressurize of master cylinder 215 Action.

4th, master cylinder release

Electromagnet YV4, YV10 and YV11 obtain it is electric, remaining electromagnet must not electricity, three position four-way electromagnetic valve I 108 control inserting The control port of valve II 103 is in smaller pressure duty through II 106 connected tank of overflow valve, system；Two-position three way magnetic valve The control port connected tank of II 218 control inserted valves Ⅸ 217；At this point, system pressure oil is controlled through two-position four-way solenoid valve VI 221 Hydraulic control one-way valve 222 is opened, and 215 epicoele of master cylinder is made to connect fuel tank, and master cylinder 215 obtains pressure release.

5th, master cylinder backhaul

Electromagnet YV1, YV2, YV3, YV6, YV10 and YV11 obtain it is electric, remaining electromagnet must not electricity, oil pump 101 export liquid Pressure oil enters master cylinder control section 200 through inserted valve I 102；The control oil of inserted valve III 201 in master cylinder control section 200 Mouth connects pressure oil, and in closed state, two-position four-way solenoid valve III 205 controls the control port connected tank of inserted valve IV 202, inserts Dress valve IV 202 and inserted valve VII 212 are opened under pressure oil effect, and pressure oil is passed through the cavity of resorption of master cylinder 215；Two-position three way electricity Magnet valve II 218 controls the control port connected tank of inserted valve Ⅸ 217, at this point, system pressure oil is through two-position four-way solenoid valve VI 221 Control hydraulic control one-way valve 222 is opened, and 215 epicoele of master cylinder is made to connect fuel tank, and 215 epicoele hydraulic oil of master cylinder flows back to fuel tank, real The backhaul action of existing master cylinder 215.

6th, liftout tank ejects

Electromagnet YV1, YV2, YV3 and YV12 obtain it is electric, oil pump 101 export hydraulic oil through inserted valve I 102 enter liftout tank Control section 300；Three position four-way electromagnetic valve II 302 is so that the control port of inserted valve Ⅺ 301 connects pressure oil and inserted valve The control port connected tank of B308, inserted valve Ⅺ 301 are closed, and inserted valve Ⅻ 303 is opened under pressure oil effect, and pressure oil enters The cavity of resorption of liftout tank 307；And the hydraulic oil of 307 epicoele of liftout tank flows back to fuel tank through check valve I 309, realizes the top of liftout tank 307 Go out action.

7th, liftout tank is retracted

Electromagnet YV1, YV2 and YV13 obtain electric, and system is in smaller operating pressure, and the hydraulic oil that oil pump 101 exports is through inserting It fills valve I 102 and enters liftout tank control section 300；Three position four-way electromagnetic valve II 302 is so that the control port of inserted valve Ⅻ 303 connects The control port connected tank of pressure oil and inserted valve Ⅺ 301, inserted valve Ⅻ 303 are closed, and inserted valve Ⅺ 301 is made in pressure oil With lower unlatching, pressure oil enters the epicoele of liftout tank 307；And the control port of inserted valve A305 is through III 312 connected tank of check valve, The hydraulic oil of 307 cavity of resorption of liftout tank opens inserted valve A305 cocurrent oil return boxes, and that realizes liftout tank 307 retracts action.

From the foregoing, it will be observed that the application method of the multi-cylinder linkage hydraulic system of hydraulic machine of the present embodiment, the realization master that can stablize Oil cylinder 215 it is fast under, it is slow under, pressurize, some row action such as release and backhaul, realize the pressing operation to workpiece；And it can also control Workpiece ejects after liftout tank 307 processed will be processed, so as to which pressing component be facilitated to remove.

Example described in the utility model is only that the preferred embodiment of the utility model is described, not to this reality It is defined with novel conception and scope, under the premise of the design concept of the utility model is not departed from, this field engineering technology people The various modifications and improvement that member makes the technical solution of the utility model, should all fall into the scope of protection of the utility model.

Claims (10)

1. a kind of multi-cylinder linkage hydraulic system of hydraulic machine, including oil-feeding control part (100) and master cylinder control section (200), Oil-feeding control part (100) is for providing hydraulic oil needed for system work, and the master cylinder control section (200) is for controlling master The action of oil cylinder (215), it is characterised in that：

The master cylinder control section (200) includes inserted valve III (201), inserted valve IV (202), two-position four-way solenoid valve II (203), shuttle valve I (204), two-position four-way solenoid valve III (205), inserted valve V (206), overflow valve IV (207), overflow valve V (208), two-position four-way solenoid valve IV (209), inserted valve VII (212), two-position three way magnetic valve I (213), inserted valve Ⅸ (217) With two-position three way magnetic valve II (218)；

The oil inlet of the inserted valve III (201) and inserted valve IV (202) is all connected with the pressure oil of oil-feeding control part (100), The oil outlet of inserted valve III (201) connects the epicoele of master cylinder (215), and the oil outlet of inserted valve IV (202) connects inserted valve V (206) With the oil inlet of inserted valve VII (212), the oil outlet connected tank of inserted valve V (206), the oil outlet of inserted valve VII (212) meets master The cavity of resorption of oil cylinder (215)；

The two-position four-way solenoid valve II (203), the P mouths of two-position four-way solenoid valve III (205) and T mouthfuls meet oil-feeding control portion respectively The pressure oil and fuel tank of point (100), the A mouths of two-position four-way solenoid valve II (203) connect the control port of inserted valve III (201), and two The A mouths of position four-way solenoid valve III (205) connect an oil inlet of shuttle valve I (204), two-position four-way solenoid valve II (203) and two The B mouths of four way solenoid valve III (205) are turned off, another oil inlet of shuttle valve I (204) connects the oil outlet of inserted valve IV (202), The oil outlet of shuttle valve I (204) connects the control port of inserted valve IV (202)；

Oil inlet, the oil inlet of overflow valve V (208) and the T of two-position four-way solenoid valve IV (209) of the overflow valve IV (207) Mouth connects the control port of inserted valve V (206), the oil outlet connected tank of overflow valve V (208), overflow valve IV (207) it is fuel-displaced Mouth connects the B mouths of two-position four-way solenoid valve IV (209), the P mouth connected tanks of two-position four-way solenoid valve IV (209), two-position four-way electromagnetism The A mouths cut-off of valve IV (209)；

The A mouths of the two-position three way magnetic valve I (213) connect the control port of inserted valve VII (212), two-position three way magnetic valve I (213) P mouths connect the oil outlet of inserted valve VII (212), the T mouth connected tanks of two-position three way magnetic valve I (213)；

The oil inlet of the inserted valve Ⅸ (217) connects the epicoele of master cylinder (215), the oil outlet connected tank of inserted valve Ⅸ (217)； The P mouths of the two-position three way magnetic valve II (218) connect the oil inlet of inserted valve Ⅸ (217), two-position three way magnetic valve II (218) T mouthfuls of connected tanks, the A mouths of two-position three way magnetic valve II (218) connect the control port of inserted valve Ⅸ (217).

2. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 1, it is characterised in that：The master cylinder control Partly (200) further include inserted valve VI (210) and two-position four-way solenoid valve V (211)；The oil inlet of the inserted valve VI (210) The oil outlet of inserted valve IV (202), the oil outlet connected tank of inserted valve VI (210) are connect, the control port of inserted valve VI (210) connects The A mouths of the two-position four-way solenoid valve V (211), the P mouths of two-position four-way solenoid valve V (211) connect inserted valve VI (210) into Hydraulic fluid port, the T mouth connected tanks of two-position four-way solenoid valve V (211), the B mouths cut-off of two-position four-way solenoid valve V (211).

3. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 1 or 2, it is characterised in that：The master cylinder (215) overflow valve VI (214) is connected between cavity of resorption and fuel tank.

4. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 1 or 2, it is characterised in that：The master cylinder Control section (200) further includes inserted valve VIII (216), inserted valve Ⅹ (219) and overflow valve VII (220)；The inserted valve VIII (216) it is connected between the oil outlet of inserted valve III (201) and the epicoele of master cylinder (215), the oil inlet of inserted valve VIII (216) connects The oil outlet of inserted valve III (201), the oil outlet of inserted valve VIII (216) are connected with control port, and connect master cylinder (215) Epicoele；Described Ⅹ (219) oil inlet of inserted valve connects the oil outlet of inserted valve III (201), and the oil outlet of inserted valve Ⅹ (219) connects oil Case, overflow valve VII (220) are connected between control port and the fuel tank of inserted valve Ⅹ (219), the control port of inserted valve Ⅹ (219) Also external control oil.

5. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 1 or 2, it is characterised in that：The master cylinder Control section (200) further includes two-position four-way solenoid valve VI (221) and hydraulic control one-way valve (222), two-position four-way solenoid valve VI (221) P mouths connect the pressure oil of oil-feeding control part (100), the T mouth connected tanks of two-position four-way solenoid valve VI (221), two four The A mouths cut-off of three-way electromagnetic valve VI (221), the B mouths of two-position four-way solenoid valve VI (221) connect the control of the hydraulic control one-way valve (222) Liquefaction mouth, the oil inlet connected tank of hydraulic control one-way valve (222), the oil outlet of hydraulic control one-way valve (222) connect the upper of master cylinder (215) Chamber.

6. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 1 or 2, it is characterised in that：Further include ejection Cylinder control section (300)；The liftout tank control section (300) includes inserted valve Ⅺ (301), three position four-way electromagnetic valve II (302), inserted valve Ⅻ (303), shuttle valve II (304), inserted valve A (305), inserted valve B (308), check valve I (309), check valve II (310) and check valve III (312)；

The oil inlet of the inserted valve Ⅺ (301) and inserted valve Ⅻ (303) connects the pressure oil of oil-feeding control part (100), inserts The oil outlet of dress valve Ⅺ (301) connects the epicoele of liftout tank (307), and the oil outlet of inserted valve Ⅻ (303) is connect under liftout tank (307) Chamber；

The P mouths of the three position four-way electromagnetic valve II (302) connect the pressure oil of oil-feeding control part (100), three position four-way electromagnetic valve The T mouth connected tanks of II (302), the A mouths of three position four-way electromagnetic valve II (302) connect the control port of inserted valve Ⅺ (301), three four The B mouths of three-way electromagnetic valve II (302) connect oil inlet of shuttle valve II (304) and check valve II (310) outlet, and shuttle valve II (304) is another One oil inlet connects inserted valve Ⅻ (303) oil outlet, and shuttle valve II (304) oil outlet connects the control port of inserted valve Ⅻ (303)；

The oil inlet of the inserted valve B (308) and the oil outlet of check valve I (309) connect the epicoele of liftout tank (307), inserting The equal connected tank of oil inlet of the oil outlet and check valve I (309) of valve B (308), the control port of inserted valve B (308) connect check valve The oil inlet of II (310)；

The oil inlet of the inserted valve A (305) connects the cavity of resorption of liftout tank (307), and the oil outlet connected tank of inserted valve A (305) is inserted The control port of dress valve A (305) connects the oil inlet of check valve III (312), and the oil outlet of check valve III (312) connects inserted valve Ⅺ (301) control port.

7. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 6, it is characterised in that：The inserted valve A (305) connection overflow valve Ⅸ (306), the also external control of control port of inserted valve A (305) between control port and fuel tank Oil.

8. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 6, it is characterised in that：The inserted valve B (308) connection overflow valve Ⅹ (311) between control port and fuel tank.

9. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 1 or 2, it is characterised in that：The fuel feeding control System part (100) have it is one or more groups of, every group include oil pump (101), inserted valve I (102) and inserted valve II (103)；

The oil inlet connected tank of one or more groups of middle oil pumps (101), the oil outlet of oil pump (101) connect inserted valve I (102) into Hydraulic fluid port；The oil outlet of the inserted valve I (102) is connected with control port, provides pressure oil；The inserted valve II (103) into Hydraulic fluid port connects the oil outlet of oil pump (101), the oil outlet connected tank of inserted valve II (103), and the control port of inserted valve II (103) connects The B mouths of two-position four-way solenoid valve I (105), the P mouths of two-position four-way solenoid valve I (105) and A mouthfuls of cut-offs, two-position four-way solenoid valve I (105) T mouth connected tanks；The overflow valve I (104) is connected between control port and the fuel tank of inserted valve II (103).

10. a kind of multi-cylinder linkage hydraulic system of hydraulic machine according to claim 9, it is characterised in that：Wherein there is one group of confession The control port of the inserted valve II (103) of oily control section (100) connects the oil inlet of overflow valve II (106), overflow valve III (107) Oil inlet and three position four-way electromagnetic valve I (108) P mouths, the oil outlet of overflow valve II (106) connects three position four-way electromagnetic valve I (108) B mouths, the oil outlet of overflow valve III (107) and the equal connected tank of T mouths of three position four-way electromagnetic valve I (108), 3-position 4-way The A mouths cut-off of solenoid valve I (108).