DE2308456C3 - Pilot operated four-way seat valve - Google Patents

Description

g ^ ™ ~ ^ _n J * be. The actuation _{makea the ^ the entire} ^, ^

gnet _{the at the lock bait}

; ^ersc "'" ° / sfeuerflüssigkeit force acting i of, Druckder Me ^g _{ßet3ti force}

Closing movement of the pilot valve of the

■ »<* - ■

^ after A, v

Claim 1, characterized in that the control fluid of the VorLuerventils controls the two seat elements (1, U) for one work connection (B) and one site element (IV) of the other work connection ^ simultaneously, the other seat element (111) des last-mentioned work connection (A) from the working fluid of the first

called working connection (B) is to be controlled and the closing body (26) of this working connection

(B), whose one seat element (I) is in operative connection via the valve tappet (12) with the valve seat body (7) of the pilot valve, associated other seat element (U) controlling the connection to the tank (T ) via a control pressure z; u acting piston element is to be moved out of the closed position in the opening direction.

3. Pilot operated four-way seat valve according to claim 2, characterized in that the piston element which actuates the closing body (2b) of the seat element (U) controlling the connection to the tank (T) is formed by a ball (25) which in the open position of this closing body ( 26) sits on a housing seat (2d) to prevent control fluid from flowing over to the tank.

The invention relates to one of a solenoid actuating <*> Seat valve pilot-operated four-way seat valve with ei switching positions according to the generic term des Proverbs 1.

Such four-way seat valves are known. The control

ig of the two pairs of seat elements in these bekanri four-way seat valves takes place through control fluid

t. Should these four-way seat valves be used as a pilot control, for example, for one on the same construction «- _gro6CT

pole

KÄng also * ^

Actuating magnet is required.

The object of the invention is darm to design _a pilot operated V.erweg-Siteventil of the type mentioned in such a way that it can be controlled with a single Voisteuerventil through a simple structure, namely without additional seals, requires as little actuation force as possible, so that the actuating magnet used can be kept correspondingly small. ...

According to the invention, this is done with the characteristic Features of claim 1 achieved.

By designing the pilot valve as a two-way valve to control the control fluid to the tank is only in the closed switching position of the closure body against the control pressure on the To print the housing seat. As a result, the required magnetic force remains at a proportionate small power stroke limited so that the actuating magnet can be dimensioned accordingly small. This small force stroke of the actuating magnet is sufficient also to move the closing body of one seat element out of its closed position, in that of the pump pressure is acted upon to move out by the touch pulse of the valve tappet.

Refinements of the invention emerge from the subclaims.

An embodiment of the invention is described below with reference to the drawing.

1 and 2 show the schematic structure of a four-way seat valve according to the invention, wherein Fig. 1 the one switching position and Fig.2 the represents another switch position. Fig.3 shows the constructive Formation of a seat element, which when a control pressure is applied through the pilot valve assumes its open switch position

In the F i g. 1 and 2 are with 1 the actuating magnet, with /, // those assigned to the working connection B.

". _tze | emente and with ///, / V the seat elements assigned to the work connection A 'are designated. The control rooms ¹ e Xa ? A ^{and 4a £} ' ^{he concerns} ff ^{enclen seat} elements /, //, IV stand' via a common control line 5 in connection. Depending on the switching position of the pilot valve formed by the valve seat body V and the housing seat surface 8 as well as the closing body Ib of the seat element / and the housing seat surface Xd either according to FIG 9 with the tank Toder according to FIG. 2 via the control chamber 1 a of the support element /, the guide gap Xf between the closing body Ib and guide recess Ie and via the valve chamber Ic and the channels 13 and 14 with the pressure medium connection PV 10 through the recess 11 of the valve housing C, connected to the valve seat body 7, the valve tappet 12 interacts with the closing body 1b of the seat element /.

G in the switching position shown by F i. 1 the actuating magnet 1 is de-energized. The closing body Ib is pressed against the seat surface Xd by the pump pressure prevailing in the space Ic of the seat element / as a result of the connection of this space by means of the channels 13 and 14 with the pressure medium connection PV. In this switching position of the closing body Ib, a connection between the space Ic and the control space la, which is connected to the tank in this switching position, is interrupted and, at the same time, the transfer of the pressurized working medium into the now pressureless control line 5 is effectively prevented. In this switching position of the closing body Ib, the working connection B is connected to the pressure medium connection PV.

In the switching position shown in FIG. 2 of the valve tappet 12, the seat body Ib was lifted from the valve tappet 12 by a contact pulse from its seat surface Xd and a connection between the control line 5 and the pressure medium connection PV was established. Since in this switching position of the valve tappet 12, in which the actuating magnet 1 is excited, the seat body 7, which is directly in frictional connection with the actuating magnet 1, rests on the housing seat surface 8 and thus the connection between the control line 5 and the line 9 leading to the tank T. interrupts, a control pressure corresponding to the pressure in the pressure medium connection PV builds up in the control line 5. This control pressure acts on the closing body Ib of the seat element / and the closing body 4b of the seat element c IVm in the direction of the housing seat surfaces Im, 4m. When the closing bodies Ib, 4b are seated on the housing seating surfaces Im, 4m, the connection of the working connection A to the tank T and of the working connection B its connection to the pressure medium connection PV connected to the pressure medium source is effectively interrupted. At the same time with the closing body 2b standing in frictional engagement via the actuating tappet 21 ball 25 acts as a power piston, is acted on by this pressure of this pilot pressure, the ball moves 25 in the direction of the spring chamber 2g of the closing body 2b and lifts the latter on the actuating plunger 21 from its Genäüsesito .achc: "" whereby the ball 25 closes the valve seat 2d. The valve chamber 2c and thus the work connection B are now connected to the tank T via the connecting line 26. Since the control line 27 leading to the control chamber 3a of the seat element /// is connected to the line 20 leading to the working connection B , when the seat element is open, the - 'control chamber 3a of the seat element /// is also connected to the tank, so that the Closing body 36 is lifted from its housing seat surface 3m by the pressure-effective annular surface 3r and sits tightly on the housing seat surface 3d. Thus, the working connection A "o is in connection with the pressure medium connection PV as shown in FIG. 2. The closing body Ib was only repelled from its upper valve seat by the plunger 12 when the reversing process just described was initiated and only a few hundredths of a millimeter from lifted from its housing seat Xd , with which the mechanical actuation process is already completed and the hydrodynamic actuation process takes place without any further external influence. This has the particular advantage that of the small magnetic stroke required anyway, only the end stroke area that produces the greater magnetic force serves as the actual working stroke the valve seat member 7 closed its associated valve seat by the magnetic force. the closing body Ib passes through the remainder of its stroke in the direction of the valve seat Xm purely hydrodynamically characterized in that on the still open valve seat due to the meantime via the opened Sitzel ement // the connection between the working port B and the tank T results in a pressure loss and thus the effective force in the closing direction is greater than in the opening direction.

If, by de-energizing the actuating magnet 1, the seat body 7 is returned to the position shown in FIG. 1 shifted the switching position shown in which the control line 5 is connected to the tank, the closing body Ib of the seat element / shifts due to the application of its pressure-effective surface Ir by the pressure medium from its in F i g. 2 into the switching position shown in FIG. 1 switching position shown, in which the connection of the control line 5 to the pressure medium connection PV is prevented. In this switching position, the working connection B is connected to the pressure medium connection at the same time. Since the ball 25 acting as a piston 45 is also relieved by the control pressure relief in the control line 5, the closing body 2b is moved into its switching position separating the connection between the working connection B and the tank T by the differential force acting on it from below and the auxiliary spring 24 according to FIG. 1 postponed. Likewise, 50 is lifted from its housing seat surface 4m by the still pressurized pressure-active surface 4r of the closing body 4b, and the connection of the working connection A to the tank is thus established. Due to the pressure acting in the control room 3a of the seat element /// as a result of the connection of this room 3a via the line 27 to the working connection B , the closing body 3a is displaced by the now effective differential forces onto the housing seat surface 3m, so that a connection of the 60 Arbeus connection A with the pressure medium connection PV again according to FIG. 1 effectively prevented

is.

The seat element // controlling the connection between the working connection B and the tank T has a * 5 conical closing body 2b, which is connected to a piston-shaped guide body 2 / " via a cylindrical extension piece 2h . This special design of the closing body 2b is unnecessary for

the actuating plunger 21 a special guide. The spring chamber 2g enclosed by the guide body 2 / is connected to the valve chamber 2c via bores 2i, 2k in the piston-shaped guide body 2f and cylindrical extension piece 2Λ, so that the closing body 2b is pressure-balanced except for the cross-sectional area of the housing seat 2m.

This pressure-effective cross-sectional area of the closing body 2b is smaller than the cross-sectional area of the ball 25 acting as a power piston, so that when the latter is pressurized, the force resulting from the pressure and the cross-sectional area of the ball and acting in the opening direction of the closing body 2b is greater than that acting in the closing direction The pressure force resulting from the application of pressure and the pressure-effective cross-sectional area of the closing body 2b and the force of the auxiliary spring 24, which also loads this closing body in the closing direction and is arranged in the spring chamber 2g , when the ball 25 is pressurized, switching of the closing body 2b in its opening direction is ensured, while pressure is relieved the ball 25 the pressure force acting on the effective cross-sectional area of the closing body 2b and the auxiliary spring 24 switches the closing body 2b back into its closed position, in which the connection between the working connection collar tank T u is open.

According to FIG. 3, which shows a structural design of the seat element //, the closing body 26 is also formed by a ball. In this case, the actuating tappet 21 is designed as an independent component and is guided in a guide part 30, which forms a common component with the guide part 31 for the ball 25 forming the power piston. The closing body 2b , designed as a ball, is also pressure-compensated except for the cross-sectional area of the housing seat 2d , in that the valve chamber 2c is connected to the spring chamber 2g via bores 33, 34 in the housing parts 35, 36 and via the annular space 37. In the switching position of the ball 25, in which the closing body 2b assumes its open position, this sits on the housing seat 2m , so that a transfer of control fluid from the control chamber 2a to the tank is effectively prevented.

In the embodiment shown, the four-way seat valve serves as a pilot part for a three-way seat valve V, also formed by seat elements, with pump connection P, working connection A ' and tank connection T. The pump connection P has a branch line Pst which connects to the pressure medium connection PV of the four-way seat valve in Connection. The pressure medium source for the working fluid thus simultaneously supplies the control fluid for the four-way seat valve that forms the pilot control part.

In a departure from the exemplary embodiment described, the seat body 7 actuated by the magnet for example designed as a separate component and with additional guide and connecting links be connected to the actuating magnet.

For this purpose 3 sheets of drawings

Claims (1)

Patent claims: 1. From a solenoid operated poppet valve pilot operated four-way poppet valve with two. Switching positions, with two seat elements assigned to each working connection such that one seat element is the flow connection of the working connection assigned to it with the tank and the other seat element is the flow connection of the other working connection with the pressure m. telquelle controls, characterized in that the pilot valve (7, 8 \ b id) to influence the control fluid for the Sch .eßkörper (ib, 2b, 3b, Ab) of the seat elements (1,11 UIlV) -5 of the four-way valve. s as a two-way eve «,, for up-Z, control of the connection for the ^
designed to the tank, st and that the valve tekor per (7) of the pilot valve via a valve tappet (12) with the closing body (tb) a «a *> work connection (B) assigned seat element (I) nrinziD based four-way seat valve must be used with a view to economic use, a solution can be found that keeps the structural dimensions within limits. In the case of the known four-way '"" JfJ., _{Such a} requirement encounters considerable problems. _This is mainly due to the constructive weight _of the projection used ^ ¹¹ T _{n Dre} iwege valves with two switching positions * ^e ™ e _ufflhren order the closure body is de-energized from the zurulk actuating magnet ^{To move Sch} ^ 'tS ^ ^U _e "f' switch position must be at '"* ^{ε a} " _{actuation magnets} excite the closure body, learn a ^ b ^ _{control fluid VQn} ^ Geger _go äusesitzfläche lifted off and after ° ^et ™ * ™ ^e "of _the switching stroke on the other