DE2013590A1 - Hydraulic pressure reducing valve - Google Patents

Description

201359Ö

WERNER & PFLEIDERER '■ Stgt.-Feuerbach,

■ '-J3 · March I97o Pat.-Eg / Hl PE 6929

Hydraulic pressure reducing valve

The invention relates to a hydraulic pressure reducing valve with arranged in a housing upper part and by one pneumatic pressure pad actuated compensating piston and a between the upper part of the housing and a housing * valve seat inserted in the lower part.

To the one specified by the pressure generator or pressure accumulator to reduce variable hydraulic pressure / and to keep the working pressure on hydraulic presses constant To keep up, there are pressure reducing valves in the pressure supply line used between pressure generator and work equipment.

The mode of operation and thus the structural design of the Pressure reducing valve is primarily dependent on whether the hydraulic working pressure is regulated under constant or variable hydraulic fluid volume got to.

In the case of hydraulic work equipment such as extrusion presses, Sinterpressan and the like «must the working pressure · -

109841/0902

BATH ORIGINAL

with verändcdicheia hydraulic fluid volume over the whole Duration of the pressing process can be kept constant. However, this requires regulating devices that operate continuously according to the principle of quantity regulation the working pressure of the respective press.

The stepless regulation of the working pressure, however, requires that the pressure reducing valve effective as a regulating device can be continuously adjusted. Up to now, however, additional safety devices have been used to secure the working pressure to be provided. Known comparative valve devices are not for hydraulic systems suitable for working with high pressures and have no safety devices.

The invention is based on the object of creating a pressure reducing valve which, with stepless regulation of the working pressure an undesired increase of the same prevents the predetermined amount.

This is achieved according to the invention in that the compensating piston on the front side facing the regulator piston one with the outflow side of the pressure reducing valve includes pressure chamber connected by a throttle gap, which is exposed to the atmosphere through the interaction of the regulator piston and compensating piston is lockable.

BAD ORiGINAb-10984 1/0902 -

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A further embodiment of the invention provides that the regulator piston to discharge the hydraulic fluid the pressure chamber has a through-hole running along its longitudinal axis.

This makes it possible in a simple manner that the pressure reducing valve at the same time without additional auxiliary devices is effective as a safety valve.

This measure also ensures at the same time that one for each arbitrary adjustable working pressure automatic overpressure protection prevents uncontrolled increase in working pressure.

In a further embodiment of the invention, the pressure chamber of the pressure cushion is optionally connected to the inflow side by means of shut-off valves of the pressure reducer or connected to a compressed air reservoir. Here are advantageous the shut-off valves are arranged in the housing cover. .

This means that either compressed air or hydraulic fluid can be used in reach the pneumatic accumulator, depending on whether the working pressure to be set is maintained or varies more often shall be.

In the drawing is an embodiment of the invention shown in section.

The pressure reducing valve consists of the upper housing part 1, the middle housing part 2 and the lower housing part 3. The The upper housing part 1 is closed in a pressure-tight manner by a housing cover 15. Between the housing middle part 2 and the lower housing part 3, and thus between the hydraulic fluid connections 4 and 5, is the valve seat 6 of the pressure reducing valve clamped and sealed by sealing rings 7.

The regulator piston 8 of the pressure reducing valve is guided in the upper housing part 1 and lower housing part 3 and in his The lower end is equipped with a valve cone 9 which interacts with the valve seat 6. One in the lower part of the housing 3 The arranged compression spring Io causes the regulator piston to close when the working pressure is exceeded at connection 5.

The compensating piston 11 of the pressure reducing valve is located in the upper housing part 1, which is connected to the regulator piston 8 facing end face has a pressure chamber 12. The regulator piston plunges into this pressure chamber under normal pressure conditions 8 with its closing cone 13 until it rests on the valve seat 13 'and thus blocks the entire pressure chamber 12 depending on the position of the regulator piston 8 and the Compensating piston 11 against the effective as Absfcrömleitung Through hole 14 from the atmosphere. If there is overpressure at connection 5., hydraulic fluid can be released after lifting

8AD ORIGINAL 109841/0902

of the compensating piston 11 via the through hole 14 and flow off the outlet connection 17 to the outside.

The control pressure chamber 16 is arranged in the housing cover 15 Shut-off valves 18 and 19 either with the hydraulic fluid connection 4 through the pressure line 2o or with a pneumatic pressure accumulator, not shown connected via terminal 21. The pneumatic pressure prevailing in the control pressure chamber 16 corresponds to that at the hydraulic fluid connection 5 exiting liquid pressure, which can be read on the pressure gauge 22. That in the hole 23 of the compensating piston 11 immersed pipe 24 is intended to prevent that when the pressure is reduced from the S -.euerdruckraum Compressed air emerges, but only the hydraulic fluid that has accumulated in the bore 23.

The mode of operation of the pressure reducing valve is as follows: via the connection 21 and the shut-off valve 19, the control pressure chamber 16 is charged up to the pressure value desired at connection 5. The compensating piston 11 and thereby also the regulator piston 8 move downwards so that the valve cone 9 opens.If the pressure is equalized between the pressure value set on the manometer and the pressure value at connection 5, there is also a delay in pressure equalization via the throttle gap 25 with the pressure chamber 12 The compression spring now slowly presses the valve cone 9 back onto the valve seat 6 via the regulator piston 8. - ^J '

1098A1 / 0902

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The particular advantage of the pressure reducing valve is that the regulator piston 8 and compensating piston 11 are separate are executed and act as a safety valve in the training described.

In the event of an unintentional increase in the pressure value in the inflow line The compensating piston becomes the working device and thus at connection 5 due to the higher pressure in the pressure chamber 12 raised.

The excess pressure energy, which is the one set on the manometer Exceeds the pressure value, flows through the through hole 14 into the open, until the pressure equalization of the compensating piston 11 drops and the valve cone 13 closes.

To achieve a higher or lower outlet pressure at connection 5, only the air pressure in the control pressure chamber is required 16 can be increased or decreased.

If the pressure ratios have to be varied frequently, hydraulic fluid can be used with a fixed air pressure via the shut-off valve 18 and the pressure supply line 2o be turned on or on. The hydraulic fluid then compresses or relieves the compressed air up to the desired pressure value

- Patent claims 109841/0902 _ßA D ORIGINAL

Claims (3)

WERBER -4 PFLEIDERER 'Stgt. ~ Feuerbach, March 18, 197o PE 6929 Paterite claims. 1. Hydraulic pressure reducing valve with a compensating piston arranged in an upper housing part and actuated by a pneumatic pressure pad and a valve seat inserted between the upper housing part and a lower housing part, characterized in that the compensating piston (IX) on the end face facing the regulator piston (8) has an offset side (5) of the pressure reducing valve by a Dx'osselspalfc {25} includes Druckraura (12) which. can be shut off from the atmosphere by the interaction of the regulator piston and compensating piston . ;. ■ .- ■ '- ■ ■. ; - ■. .. - ■ '.' ■. 2. Hydraulic pressure reducing valve according to claim 1 _#, characterized in that the cone piston (8) for discharging the pressure fluid from the pressure chamber (12) has a through bore (14) extending in its longitudinal axis. 3. Hydraulic pressure reducing valve according to claims 1 to 2, characterized in that the pressure chamber (16) is optional '' with shut-off valves ₍ (18 and 19) to the inflow side (4) of the pressure reducing valve or with a compressed air reservoir - ■. "■■ ·
is bound. 109B41 / 0902 4, hydraulic pressure reducing valve according to claims 1 to 3, characterized in that the shut-off valves (18 and 19) are arranged in the housing cover (15). 10984 1/0902 bad OfliQlNAL