DE8027421U1 - PRESSURE CONTROL VALVE - Google Patents

Description

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A 14 430 Herion-Werke KG

description

The invention relates to a pressure control valve for pneumatic and hydraulic pressure medium, with a valve piston, a Promäranschluss, a secondary connection and a pressure relief connection, a valve part between the primary connection and the secondary connection, as well a valve part between the secondary connection and relief connection.

Pressure regulating valves or pressure reducing valves have the task of providing a to regulate the high secondary pressure to a lower secondary pressure. In the event of an increase in the secondary pressure due to external influences the excess amount of pressure medium (e.g. air or hydraulic fluid) must be vented or discharged to a tank.

There are now known pressure reducing valves which are designed as slide valves are. However, these valves have the disadvantage that between the primary side and the secondary side, and between the secondary side and Tank connection leak oil occurs, which is disadvantageous in storage operation, especially when several valves are connected in parallel is because the memories can empty quickly.

In contrast, the invention is based on the object of developing a valve of the type mentioned at the outset in such a way that, if it is avoided this disadvantage a perfect, reliable function of the valve is achieved.

According to the invention this is achieved in that the valve parts are designed as seat valves.

The seat valves are here expediently when using a pneumatic pressure medium in the form of poppet valves with soft

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seals, with a hydraulic pressure medium in the form of a cone seat valve en trained.

For the purpose of pressure relief, the valve seat and bellows resp. Pistons have the same effective diameter.

To relieve the soft seals, the stroke of the Valve head of the seat valve between the secondary connection and the relief connection in its closing direction by a stop fixed to the housing limited.

The valve disk of the seat valve between the promare connection and the secondary connection can be designed to be axially adjustable, whereby the stroke and the control point of the magnet actuating the valve are fixed can.

In order to avoid seal friction, it can be provided that the valve to connect the piston to the valve housing via a bellows.

The valve disk of the seat valve can also advantageously be provided with a damping piston between the secondary connection and the relief connection in order to prevent the system from oscillating.

Exemplary embodiments of the invention are based on the following the drawing explained in which the

Fig. 1 - 3 in section a pressure control valve in different switching positions show for pneumatic pressure medium.

Fig. 4 shows in section a pressure control valve for hydraulic pressure medium

The pressure control valve 10 according to FIG. 1 has a housing 12 with a primary connection 14 for a pressure medium with high primary pressure, in this case

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e.g. air, a secondary connection 16, in which the pressure depends on the setting of the control magnet 34 of the valve is regulated to a lower pressure than the primary pressure, and a relief connection 18, which in this case, i.e. when using a pneumatic pressure medium, e.g. ventilates to the atmosphere.

In the housing 12, a valve piston 20 is axially displaceable. The valve piston is provided at its lower end in the drawing with a valve disk 24, which together with a valve seat 22 in the housing 12 forms a seat valve. A soft seal can be used as the seal 26. The valve disk 24 is in the illustrated embodiment screwed onto the valve piston 20 so that it can be adjusted in the axial direction. The thread is suitable, not shown in detail Sealed way, and there may also be provided means to the To lock the valve plate 24 on the valve piston 20 in the set position.

At the upper end in the drawing, the valve piston 20 is marked with a ^. Valve seat 28 is provided, which together with a valve disk 30, which is suitably guided in the housing, also forms a seat valve. A soft seal 32 can also be used here as a seal.

The valve disk 30 is on the side facing away from the valve seat 28 acted upon by a magnetic plunger 36 of the regulating magnet 34.

The seat valve 22, 24 is between the primary connection 14 and the Secondary connections 16, while the seat valve 28, 30 lies between the secondary connection 16 and the vent connection 18.

A stop 38 is formed in the housing, on which the valve disk 30 is seated in the position according to FIG. 2, as will be explained in detail below. In the embodiment shown here, the valve piston 20 is connected to the housing 12 via a bellows 40. A printing

spring 42, located on one side on the housing and on the other supported on the valve piston, acts on the latter against the direction of force of the control magnet 34.

The valve of FIGS. I to 3 operates as follows.

At the primary connection 14 is the pressure medium with high primary pressure. Both seat valves 22, 24 on the one hand and 28, 30 on the other hand, are closed, i.e. the control valve is located in the one controlled by the control magnet 34 specified pressure range. The effective area of the seat valve 22, 24 and the effective area of the bellows 40 are the same size, with which the valve piston 20 is relieved of pressure in itself. Furthermore, the effective area of the seat valve 28, 30 is equal to effective area of the seat valve 22, 24.

The valve disk set at the control magnet 34 acts on the valve disk 30 from above Force. The force of the control spring 40 and a force that results from the product of Secondary pressure times the effective area of the seat valve 28, 30 results. The valve piston 20 is for this purpose with a continuous axial bore 48 is provided, which is constantly in communication with the secondary connection 16, so that the secondary pressure on the valve disk 30 counter to the force of the rule magnet 34 acts.

In the switching position of the pressure control valve shown in Fig. 1, these forces are balanced, that is, both seat valves 22 _S 24 and 28, 30 are closed, that is, the connection from the primary connection 14 to the secondary connection 16 is blocked, as is the connection from the secondary connection to the vent connection 18 .

If a higher secondary pressure is now required, the force of the Control magnet 34 against the force of the compression spring 42 increased. Since with this increase in the force of the control magnet, the system is no longer

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is in equilibrium, the valve disk 30 is driven by the magnet The plunger 36 in FIG. 2 is moved downwards and thereby the valve disk 2 < lifted from the valve seat 22 and thus this valve is opened. The valve disk 30 moves downwards until it hits the stop 38 of the housing 12 is seated, as shown in FIG. The load on the soft seal 32, which is usually only spring by the force 42 is acted upon, is thereby limited and an overload avoided.

It should be added here that the soft seal 26 only is loaded by the force of the control spring 42, since the system is pressure-balanced in itself. (Figures 1 and 3).

After the seat valve 22, 24 has opened, pressure medium flows from the Primary connection 14 to the secondary connection 16 until the through the Control magnet 34 predetermined secondary pressure is reached. As soon as this is the case, the forces and the seat valve are balanced again 22, 24 closes again and the pressure control valve assumes the position shown in FIG. 1.

If a lower secondary pressure is desired, the force of the control magnet 34 acting on the valve disk 30 is correspondingly decreased. By the secondary pressure, which acts against the force of the control magnet on the valve disk 30, the latter is from Valve seat 28 lifted and the seat valve 28, 30 opened, as shown in FIG. 3, whereby a connection from the secondary connection 16 to the Vent connection 18 is made. The pressure medium can then flow off from the secondary connection 16 to the ventilation connection 18 as long as until the balance of forces is reached again, i.e. until the force of the control spring 42 plus the force from the secondary pressure is times more effective Area of the valve seat 28 is equal to the force of the rule magnet 34.

If these forces are balanced, the control valve again takes the

position shown in Fig. 1 a.

The valve disk 30 is, as shown in the drawing, with a Damping piston 44 provided, which is in an enlarged bore 46 of the Valve piston 20 protrudes. The bore 46 is in communication with of bore 48. The diameters of damping piston 44 and bore are now chosen so that the area of the bore 48 is larger than the area of the annular gap between the damping piston 44 and the bore 46, so that the resulting differential force on the lower end face of the damping piston 44 against the direction of force of the Control magnet acts. This prevents the system from oscillating.

Since both soft seals 26, 32 only by the force of the control spring are acted upon, and also the movement of the valve plate 30 is limited by the stop 38, an overload of the soft seals is avoided. Due to the axial adjustability of the valve disk 24 on the valve piston 20, the stroke and the control point of the magnet can be adjusted and fixed. As a control magnet .can a proportional magnet can be used that is force-controlled or can be stroke regulated. As a result of the use of a bellows, the otherwise required seals can be dispensed with, which also eliminates the seal friction.

It is also advantageous that as a result of the use of seat valves no leakage occurs.

It has been stated above that the effective diameters of the valve seats 28 and 22 are the same. If, on the other hand, the valve seat 28 is designed with a smaller diameter than the valve seat 22, this results a difference between opening pressure and closing pressure, which in some Cases may be of interest.

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In the embodiment according to FIG. 4, which works with a hydraulic pressure medium, for example pressure oil, the seat valves are designed as cone seat valves. The valve piston 20 is slidably guided in a valve bushing 56 and is provided with a valve cone 52 which, together with the valve seat 22 ′ formed on the valve bushing 56, forms a seat valve between the primary connection 14 and the secondary connection 16. At the upper end of the valve piston in the drawing, the valve piston is provided with a valve seat 28 which cooperates with a valve cone 54 and forms a seat valve. The valve cone 54 is suitably connected to the magnetic plunger 36.

The function of this valve is the same as that of the Ve.ntiles according to FIGS. 1 to 3.

In the position shown in Fig. 4, both seat valves are closed. The valve piston 20 is acted upon by the control spring in the closing direction of the two seat valves. In the illustrated Position, the forces are balanced. If the force of the regulating magnet is increased, the seat valve 22, 52 is opened and that Pressure medium flows from the primary connection 14 via an annular space 58, a transverse bore.60 and an annular space 62 through the open seat valve 22, 52 to the secondary connection 16. The secondary pressure increases accordingly, until the force of the rule spring and the force resulting from the secondary pressure on the valve cone 54 is equal the magnetic force, whereupon the seat valve 52, 22 closes again and the connection from the primary connection 14 to the secondary connection 16 is blocked.

If, on the other hand, the force of the regulating magnet is reduced or increases Pressure in the secondary connection 16 as a result of an external force or, for example, due to an increase in the temperature of the pressure medium, the sum of the Forces (spring force + force as a result of the secondary pressure) on the valve cone are greater than the oppositely directed force of the control magnet, whereupon

the valve seat 28, 54 opens and the pressure medium from the secondary connection can flow through the bore 48, the open seat valve 28, 54 and an intermediate chamber 64 to the tank connection 18 until the pressure at the secondary connection 16 has fallen again so far that the forces are balanced, whereby the system again assumes the position shown in FIG.

If the diameter of the valve seat 28 is smaller than that of the valve seat 22, so, as already stated, the closing pressure between the primary connection 14 and the secondary connection 16 is less than the opening pressure between the secondary connection 16 and the tank connection 18. The secondary pressure in connection 16 therefore fluctuates between these two values. the The control spring 42 has the same effect.

In most use cases, therefore, behave as a good rule To achieve the same seat diameter and the spring 42 will only be so strong that, when the pressure medium flows from the secondary connection 16 to the tank connection 18, the seat valve 22, 52 straight is still kept closed.

Claims (10)

IB I)) ff · I ■ I · till · ■■ · It Λ 9 · · A 14 430 Herion-Werke KG / isprliche 1. Pressure control valve for pneumatic and hydraulic pressure media, with a valve piston, a primary connection, a secondary connection and a pressure relief connection, a valve part between the primary connection and the secondary connection and a valve part between secondary connection and relief connection, thereby g e k e η η ζ e i c h η e t that the valve parts as seat valves are trained. 2. Pressure regulating valve na.cn claim 1, characterized in that the seat valves in the form of poppet valves (24, 30) are formed with soft seals (26, 32). 3. Pressure control valve according to claim 1, characterized in that that the seat valves are designed as cone seat valves (52, 54). 4. Pressure control valve according to one of the preceding claims, characterized characterized in that the valve parts (22, 28) the have the same effective diameter. 5. Pressure regulating valve according to claim 2, characterized in that that the stroke of the valve disk (30) in its closing direction is limited by a stop (38) fixed to the housing. 6. Pressure control valve according to claim 2, characterized in that that the valve plate (24) is arranged axially adjustable on the valve piston (20). 7. Pressure regulating valve according to claim 1, characterized in that ne t that the valve piston (20) is connected to the valve housing (12) via a bellows (40). 8. Pressure regulating valve according to claim 2, characterized in that the valve disk (30) with a damping piston (44) is provided. 9. Pressure control valve according to claim 7, characterized in that that the effective diameter of the bellows (40) is equal to the effective diameter of the valve parts (22, 28). (Fig. 1-3), 10. Pressure regulating valve according to claim 1, characterized in that that the diameter of the valve piston (20) is equal to the effective diameter of the valve parts (22, 28). (Fig. 4).