CN1356481A

CN1356481A - Balancing valve

Info

Publication number: CN1356481A
Application number: CN 01139273
Authority: CN
Inventors: 刘富良; 卢永松
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-12-27
Filing date: 2001-12-27
Publication date: 2002-07-03
Anticipated expiration: 2021-12-27
Also published as: CN1133821C

Abstract

A balancing valve for the engineering machine with 8-50 tons of lifting weight is composed of main valve and pilot valve. The said main valve consists of cylindrical valve body and main valve core. The said pilot valve is positioned in the main valve core. The core of pilot valve is linked to main valve core via springs. The main valve core is linked to valve body via more springs with different spriral directions and rigidities. Its advantages include correct, sensitive and reliable control, and preventing the burble dropping down of load.

Description

A kind of equilibrium valve

Technical field

The present invention relates to a kind of valve, especially refer to a kind of hydraulically balanced valve technical field in flexible and the luffing cylinder circuit in 8 tons to the 50 tons engineering machinery that play liter weights that is applicable to.

Background technique

Engineering machinery in the modern times, in the machinery such as building machinery, widely applied the hydraulic pressure load bearing system, wherein equilibrium valve is the crucial hydraulic element of this type systematic, the quality of its performance directly affects machine performance, and existing hydraulically balanced valve mainly is made of control valve and main valve, common have two kinds of single-stage and leading types, single-stage main valve and control valve are for to connect side by side, the leading type main valve is nested the connection with control valve, the hydraulically balanced valve of above-mentioned two kinds of forms forms owing to adopting outer closed assembly to join, complex structure, volume is bigger, be not easy to be directly installed on the filler opening place of oil cylinder, if adopt oil pipe to connect, make and to allow system more complicated, and the easy leakage of oil of pipe and breaking, influenced the functional reliability of equilibrium valve, for this reason, a kind of new equilibrium valve is devised, as application number is 87202245U " cartridge balanced valve ", this scheme adopts main valve plug to be inserted in the valve support chamber, guide's spool is inserted in the simple chamber of main valve plug, because adopt simple plug-in mounting mode structure, thereby compact structure, volume is little in light weight, can be directly installed on the filler opening place of oil cylinder or motor, but this equilibrium valve still is positioned at the outside of oil cylinder or motor, must make the whole system volume bigger, moreover, this equilibrium valve adopts the hydraulic coupling feedback principle, though improved working stability to a certain extent, sensitivity descends, and insufficient sensitivity also can influence its proper functioning; Also have its control spool work to control according to a control mouthful oil-feed, a mouthful inlet is provided with damping in control, have one-way valve in the damping, bring unsafe factor for like this braking and locking function of valve body, when control valve is positioned at the neutral position, because the closure of pilot valve is subjected to the control of its spring and control spool, if the one-way valve in the damping is closed at once, certain hydraulic oil is locked in the control spool chamber, make the control valve closure that can not normally reset, also certainly will influence the pilot valve closure, make the hydraulic oil of filler opening enter oil outlet, make the braking and locking functional failure of valve body by pilot valve.Control the direct control orifice aperture of spool size in addition, because the spring rate that matches is certain, when the operation sudden change, because sensitivity is not high, its dynamic and static state property is still undesirable.

Summary of the invention

Technical problem to be solved by this invention is to overcome above-mentioned defective, provides that a kind of more reasonable structure, sensitivity are moderate, good reliability, can directly insert the equilibrium valve in the oil hydraulic cylinder.

The present invention solves the problems of the technologies described above the technological scheme that is adopted: equilibrium valve comprises main valve, pilot valve, wherein main valve comprises valve pocket, main valve plug, on the outer side surface of valve body, be provided with main hydraulic fluid port A and B, described pilot valve is positioned at main valve plug, guide's spool is connected with spring, above-mentioned each valve all comprises two chambeies that are positioned at the spool front and back, and it is characterized in that: (1) described valve pocket is cylindrical shell; (2) a plurality of springs that main spool spring is respectively left-handed and dextrorotation, mutually nested and rigidity differs are formed, and main valve plug links to each other with valve pocket by a plurality of springs; (3) in an end face of valve pocket, be provided with control valve plug, this control valve plug and main valve plug offset and can move vertically in valve pocket, damping hole b2 and the back cavity of hydraulic fluid port c1 connection pilot valve and the ante-chamber of main valve of mutual perforation axially and radially located to be provided with respectively in the control valve plug middle part, and control valve plug end and pilot valve spring offset; (4) described main valve plug upper forepart radially, radially be respectively equipped with back cavity and main hydraulic fluid port B that hydraulic fluid port a1 and b4 are communicated with pilot valve on guide's spool; (5) on main valve plug, be parallel to and be axially arranged with back cavity and the main hydraulic fluid port B that damping hole b5 is communicated with main valve plug; (6) rear portion radially is provided with ante-chamber and the main hydraulic fluid port A that a hydraulic fluid port a6 is communicated with pilot valve on described main valve plug.

Can be provided with a plurality of boss on the tube inwall of described valve pocket; The outer middle side part of main valve plug is a plurality of coniform, and circular cone side and above-mentioned boss match;

The outside, described main valve plug middle part wherein can be provided with a plurality of skewed slots on the circular cone side;

Be provided with the damping plug that fixes with it in the end face that described control valve plug and main valve plug offset, the spring of this damping plug and pilot valve offsets and is axially arranged with above-mentioned damping hole b2 within it;

The outer ring of described valve pocket is provided with a plurality of grooves around the circumference side;

Also be provided with the control cylinder between control valve plug and valve pocket in the described valve body end face that is provided with control valve plug.

Compared with prior art, the invention has the advantages that: because valve pocket adopts tube structure, so can directly insert the oil hydraulic cylinder head, again because a plurality of spring structures that main spool spring adopts rigidity to differ, mix the skewed slot on the main valve plug circular cone side, feasible control is more accurate, sensitive, reliably, also have under the situation of the damaged decompression of flexible pipe, guide's spool in the main valve plug can be closed the oil circuit between main hydraulic fluid port B and A automatically rapidly, can prevent that load stall from descending, play the effect of a hydraulic lock, lock function is also more safe and effective when braking in addition, avoids some unsafe factors.

Description of drawings

Fig. 1 is that embodiment of the invention structure is cutd open and shown schematic representation;

Fig. 2 is the main valve plug structural representation;

Fig. 3 is the hydraulic schematic diagram of present embodiment.

Embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

Referring to Fig. 1, equilibrium valve comprises main valve and pilot valve, above-mentioned each valve all comprises two chambeies that are positioned at the spool front and back, wherein main valve comprises valve pocket 7 and main valve plug 6, described valve pocket 7 is cylindrical tube, on the outer side surface of valve pocket 7, be provided with two main hydraulic fluid port A and B, the outer ring of valve pocket 7 is provided with three each and every one grooves 11 around the circumference side, in order to inlay seal ring, seal after making equilibrium valve insert oil hydraulic cylinder, the tube inwall of valve pocket 7 is provided with two

boss

12 and 12,13 of 13, two boss form an oil pocket a4; The outer middle side part profile of main valve plug 6 is two circular cone side a2 and a5 separated by a distance, two circular cone side a2 and a5 respectively with valve pocket 7 inwalls on two

boss

13,12 match, wherein a circular cone side a2 is provided with upper and lower totally two skewed slots 15, referring to Fig. 2, make main valve plug 6 when valve pocket 7 moves, the main valve plug 6 at this place and 13 of valve pocket 7 boss become a settable orifice, and another circular cone side a5 forms line with valve pocket boss 12 and contacts, to guarantee intact sealing;

In valve pocket 7, front end at main valve plug 6 has a control valve plug 1 mutually with it, this control valve plug 1 Cheng “ Shang " the shape cylinder; concentric and be positioned on control valve plug 1 shoulder control cylinder 2 is arranged with control valve plug 1; that this control cylinder 2 is threaded with valve pocket 7; be provided with 4 circular holes 14 of concentric distribution in control cylinder 2, the gripping when assembling in order to equilibrium valve; Control valve plug 1 is tightly connected with control cylinder 2, and can in control cylinder 2, move vertically, be fixed with a damping plug 3 with screw thread on the face that control valve plug 1 and main valve plug 6 offset, be axially arranged with damping hole b2 in this damping plug 3, control valve plug 1 middle part is radially located to be provided with the hydraulic fluid port c1 that connects with damping hole b2 and is communicated with the back cavity b3 of pilot valve and the ante-chamber b1 of main valve, a main spool spring that offsets with the rear end of main valve plug 6, this main spool spring is respectively by left-handed and dextrorotation, mutually nested and

dual spring

8 and 10 that rigidity differs is formed, one end of dual spring is positioned on the main valve plug 6, the other end and spring seat 9 offset, spring seat 9 respectively with valve pocket 7, main valve plug 6 is tightly connected;

In the inner chamber of main valve plug 6, be inserted with guide's spool 5, this guide's spool 5 links to each other with control valve plug 1 by pilot valve spring 4, described main valve plug 6 upper foreparts radially, radially be respectively equipped with back cavity b3 and main hydraulic fluid port B that hydraulic fluid port a1 and b4 are communicated with pilot valve on guide's spool, on main valve plug 6, be parallel to and be axially arranged with back cavity b6 and the main hydraulic fluid port B that damping hole b5 is communicated with main valve, the rear portion radially is provided with ante-chamber a3 and the main hydraulic fluid port A that a hydraulic fluid port a6 is communicated with pilot valve on described main valve plug 6.

The foregoing description is owing to adopt cylindrical tube, all elements are installed on the same axis, then can directly insert the head of oil hydraulic cylinder, but also can outside the foregoing description, be with valve body 16, see Fig. 3, then can be installed in the oil hydraulic cylinder outside to this equilibrium valve, link to each other with oil hydraulic cylinder, to satisfy the needs of different occasions by pipeline.

Fig. 4 is that the present invention is applied in the hydraulic schematic diagram on the winch, and the main hydraulic fluid port A on this valve pocket 7 links to each other with the hydraulic fluid port A1 of 3-position 4-way control valve H, main hydraulic fluid port B and oil hydraulic cylinder G rodless cavity B ₁Mouthful link to each other, the hydraulic fluid port B3 of 3-position 4-way control valve H respectively with the rod chamber B of oil hydraulic cylinder G ₂, control valve plug 1 outside control mouth Pp link to each other, other two hydraulic fluid port P and the O of control valve H connect pressure oil-source and oil sump tank respectively.

The work control procedure of this valve is as follows: (1) normally hoists load: H gets to the left side the 3-position 4-way control valve, pressure oil-source communicates with the hydraulic fluid port A1 of control valve H, pressure oil enters the main hydraulic fluid port A on this valve pocket 7, hydraulic fluid port a6 radially on main valve plug 6, the ante-chamber a3 of pilot valve, overcome the pretightening force of pilot valve spring 4, guide's spool is moved to left, pressure oil is again through the space of sealing cone a7 and main valve plug 6, hydraulic fluid port a1 in the main valve plug 6, main hydraulic fluid port B on the valve pocket 7 enters the rodless cavity B1 of oil hydraulic cylinder, promoting load W rises, the oil return of the rod chamber B2 of oil hydraulic cylinder G is through pilot line B2-B3, the hydraulic fluid port B3 of control valve H gets back to oil sump tank, fluid among this valve master hydraulic fluid port B flow to the back cavity b6 of main valve by damping hole b5 simultaneously, by the hydraulic fluid port b4 on guide's spool 5, the back cavity b3 of pilot valve, damping hole b2, hydraulic fluid port c1 flow to the ante-chamber b1 of main valve, pressure and main valve dual spring 8 in main valve ante-chamber b1 and the generation of back cavity b6 area difference, 10 effects down, the conical surface a5 of main valve plug 6 is close to the boss 12 on the valve pocket 7, cut off the path of main hydraulic fluid port B to main hydraulic fluid port A, fluid among the main hydraulic fluid port B can not flowed backward on the main hydraulic fluid port A, and this moment, equilibrium valve only played the effect of an one-way valve.(2) load W speed limit is transferred: 3-position 4-way control valve H is got to the right, this moment, pressure oil-source linked to each other with hydraulic fluid port B3 among the control valve H, and oil sump tank links to each other with hydraulic fluid port A1, pressure oil enters the rod chamber B2 of oil hydraulic cylinder through pilot line B2-B3, pressure among the pilot line B2-B3 acts on control valve plug 1 by the outside control mouth Pp of control valve plug 1, when oil pressure hour, control valve plug 1 overcomes the pretightening force of the less spring 10 of the rigidity of main valve, when if oil pressure is big, control valve plug 1 overcomes the dual spring 8 of main valve, 10 pretightening force, main valve plug 6 is moved to right, open the sealing of 12 of conical surface a5 and valve pocket boss, make the main hydraulic fluid port B of fluid on valve pocket 7 among the oil hydraulic cylinder rodless cavity B1, restriction a2, oil pocket a4, the space that conical surface a5 and valve pocket boss are 12 flow to the main hydraulic fluid port A of this valve, and the hydraulic fluid port A1 in control valve H flows back to oil sump tank again; And the fluid among the main simultaneously hydraulic fluid port B flow to the back cavity a3 of pilot valve through hydraulic fluid port a1 on the main valve plug 6 and the hydraulic fluid port b4 on guide's spool 5, under the effect of the restoring force of this pressure oil and pilot valve spring 4, guide's spool 5 is moved to right, sealing cone a7 is close to main valve plug 6, has cut off the path of main hydraulic fluid port A to main hydraulic fluid port B.If the control mouth pressure raises suddenly, because the drag effect at the restriction place on the conical surface a2, the speed that load is descended is not undergone mutation, main valve plug 6 moves to right simultaneously, because main valve plug 6 outer side surface places are provided with two skewed slots 15, it is big that the oilhole cross section of

skewed slot

15 and 13 formation of valve pocket boss also becomes thereupon, thereby slowly improve rate of descent, improved dynamic stability.(3) load is still in midair: in the middle of 3-position 4-way control valve H is got to, the path of cut-out pressure source and control valve H hydraulic fluid port A1, guide's spool 5 is under the pressure effect of pilot valve spring 4 and load generation, and sealing cone a7 is close to main valve plug 6; And main valve plug 6 is under the pressure effect of main valve plug

dual spring

8,10 and main valve ante-chamber b1 and the generation of back cavity b6 area difference, sealing cone a5 is close to valve pocket boss 12, cut off the path between inner main hydraulic fluid port A of this valve and the B fully, oil hydraulic cylinder G rodless cavity internal pressure oil can not flow backward to control valve H oil sump tank through this valve, stops load to descend voluntarily.(4) the damaged Braking mode protection of flexible pipe: be connected with high pressure hose usually between control valve H and this valve master hydraulic fluid port A; when negative moment is transferred load; high pressure hose does not bear high pressure; but when normally promoting load; high pressure hose will bear and overcome the high pressure that load produces; when frequently bearing high pressure and long-term work ageing of rubber and cause that high pressure hose is damaged; this valve master hydraulic fluid port A instantaneous loss of pressure; under the pressure effect of pilot valve spring 4 and load generation; the sealing cone a7 of pilot valve closes rapidly; cut off the path between main hydraulic fluid port A and the hydraulic fluid port B, stop load to be fallen voluntarily.

Protection scope of the present invention is not subjected to the restriction of the structure of the foregoing description; even the structure to embodiment is done some change; be designed to four nested in twos springs as dual spring; change 3 or 4 etc. into as the skewed slot 15 on the main valve plug circular cone side a2, such scheme still belongs to protection scope of the present invention.

Claims

1. equilibrium valve, comprise main valve, pilot valve, wherein main valve comprises valve pocket (7), main valve plug (6), the outer side surface of described valve pocket (7) is provided with main hydraulic fluid port (A) and main hydraulic fluid port (B), described pilot valve is positioned at main valve plug (6), guide's spool (5) is connected with pilot valve spring (4), and above-mentioned each valve all comprises two chambeies that are positioned at the spool front and back, it is characterized in that:

(1) described valve pocket (7) is cylindrical shell;

(2) a plurality of springs that main spool spring is respectively left-handed and dextrorotation, mutually nested and rigidity differs are formed, and main valve plug (6) links to each other with valve pocket (7) by a plurality of springs;

(3) be provided with control valve plug (1) in the end face of described valve pocket (7), this control valve plug (1) offsets with main valve plug (6) and can move vertically in valve pocket (7), damping hole (b2) and hydraulic fluid port (c1) that mutual perforation axially and is radially located to be provided with respectively in control valve plug (1) middle part are communicated with the back cavity (b3) of pilot valve and the ante-chamber (b1) of main valve, and control valve plug (1) end and pilot valve spring (4) offset;

(4) described main valve plug (6) upper forepart radially, radially be respectively equipped with hydraulic fluid port (a1) on guide's spool (5) and (b4) be communicated with the back cavity (b3) and the main hydraulic fluid port (B) of pilot valve;

(5) go up, be parallel to the back cavity (b6) and the main hydraulic fluid port (B) that are axially arranged with damping hole (b5) connection main valve at main valve plug (6);

(6) go up the rear portion at described main valve plug (6) and radially be provided with ante-chamber (a3) and the main hydraulic fluid port (A) that a hydraulic fluid port (a6) is communicated with pilot valve.

2. equilibrium valve according to claim 1 is characterized in that described valve pocket (7) tube inwall is provided with a plurality of boss, and the outer middle side part of main valve plug (6) is a plurality of coniform sides, and circular cone side on the main valve plug (6) and above-mentioned valve pocket (7) boss match.

3. equilibrium valve according to claim 2 is characterized in that the outside, described main valve plug (6) middle part wherein is provided with a plurality of skewed slots (15) in a circular cone side.

4. equilibrium valve according to claim 1, it is characterized in that being provided with the damping plug (3) that fixes with control valve plug (1) in the end face that described control valve plug (1) and main valve plug (6) offset, this damping plug (3) offsets with pilot valve spring (4) and be axially arranged with above-mentioned damping hole (b2) in damping plug (3).

5. equilibrium valve according to claim 1 is characterized in that the outer ring of described valve pocket (7) is provided with a plurality of grooves (11) around the circumference side.

6. equilibrium valve according to claim 1 is characterized in that also being provided with the control cylinder (2) that is positioned between control valve plug (1) and valve pocket (7) in described valve pocket (7) end face that is provided with control valve plug (1).