DE8017273U1 - Adjustable throttle valve - Google Patents

Description

Bag. 1196 -A-

A well-known throttle valve with hydraulic sequence control from Towler weisi; a throttle piston on which on its side facing away from the passage side on the one hand through an inlet channel with the oil inlet and on the other hand is connected to the oil drain by an axial drain channel, with a follower piston, which is connected to the axial bore is guided in alignment, forms an edge control with this and the follower piston as a function of an actuating piston is hydraulically positioned by a pilot pressure specified by means of a pilot control stage. To this point the well-known throttle valve on a spring which mechanically connects the control piston with the control piston and through this type of mechanical return of the position of the actuating piston to the position of the pilot stage is a regulation of the pilot pressure.

The object of the invention is to provide such a throttle valve to be trained in such a way that the complex pilot control and regulation of the pilot pressure are dispensed with and the area of application of the valve can be expanded without impairing the function and functionality.

This is done according to the invention in that the setting piston and follower piston are mechanically independent of one another be guided by the follower piston penetrating the setting piston and only connected to it by a stop is. As a result, the follower piston can, in the opening direction, be independent of the setting piston and the setting piston move in the closing direction independently of the follower piston, and it becomes possible to use the control piston and follower piston supported by independent springs. Thus, the spring supporting the actuating piston can be used

Pilot pressure can be adjusted without the function of the follower piston to affect.

A dead path is preferably provided for the upward movement of the actuating piston. This ensures that the Follower piston with its entire spring force in the oil drain opening of the throttle piston is closing if none Pilot pressure is applied.

If - as is also proposed - the throttle valve is designed with regard to the flow direction so that the system pressure with reverse flow direction the throttle piston Adjusted against the spring force of the follower piston, the valve acts as a combined throttle and check valve.

The scope of the throttle valve according to the invention can also be expanded by increasing the pilot pressure by means of a pressure relief valve connected in parallel, preferably an electromagnetically proportionally controlled pressure relief valve is pilot controlled.

In the following an embodiment of the invention is described with reference to the drawing.

The valve shown in the drawing acts as a throttle valve in the direction of flow indicated by arrows 4 and 5 and as a check valve in the opposite direction of flow. The valve has in the housing 1 the Throttle piston 6, which closes sealingly on seat 32 and with its differential piston surface 33 of the Pressure P 1 in the oil duct 2 coming from the pump is loaded. In the illustration, the drainage channel 3 is closed,

dader the pump pressure P 1 via the oil inlet channel 7 also in that Lock cylinder 9 is applied. The cylinder space 9 is with the Drain side connected via the drain channel 8. This is however, in the rest position of the follower piston 10, it is closed in the seat 11. The follower piston 10 is in the guide 12 linearly guided and penetrates the concentrically arranged actuating piston 13 in such a way that both are movable relative to one another are. The actuating piston 13 is guided in a sealing manner in the actuating cylinder 14 and can be operated via the pilot control pressure line 21 are pressurized. Its rest position is predetermined by the collar 15. The adjusting piston 13 and the follower piston 10 act with one another through the stop 16 of the follower piston 10, with the actuating piston 13 having a certain degree to this Dead path 34 has to cover. The follower piston is on stop 16 by the spring supported in the spring plate 18 against the Throttle piston 6 or seat 11 pressed. The actuating piston is supported on the collar 15 by a spring 19 against the spring plate 20 and placed against the collar 15 on the housing.

The combined throttle and check valve shown up to this point works in the direction of flow Arrows 4 and 5 as follows:

On the differential piston surface 33 of the throttle piston 6 the pump pressure is applied. However, since the oil drain channel 8 is closed by the follower piston 10 in the seat 11, predominates the closing force and the throttle piston 6 closes the oil inlet in the consumer channel 3. If now over the If a certain pilot pressure is given into the actuating cylinder 14, the actuating piston moves against the force of the spring 19 upwards. After overcoming the dead path 34, the follower piston also becomes with this movement 10 taken by means of stop 16 and moved against the spring force 17 upwards. There is now a Equilibrium position of the actuating piston 13, which by

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dan pilot pressure on the one hand and predetermined by the travel-dependent spring forces of springs 17 and 19 on the other hand is. Because the follower piston 10 lifts off the seat 11, the oil in the lock cylinder 9 can flow through the oil drainage channel 8 escape, so that the closing pressure in the cylinder 9 and the pressure on the differential piston surface 33 drops Pump pressure causes the throttle piston 6 to lift off. In this case, the throttle piston 6 again approaches that through seat 11 formed edge control with the follower piston 10, until the closing pressure in the cylinder 9 increases again is that the throttle piston 6 is in a state of equilibrium.

The oil flow from the pump to the consumer is throttled in a defined manner depending on the pilot pressure.

Here it is still possible to control the pilot pressure by adding a pressure relief valve and in particular a proportional pressure relief valve to control defined. The pressure relief valve consists of the housing 23 with the pilot pressure channel 24, the seat 25 and the pilot piston 26. By means of the plunger 27 and the pilot magnet 28 the pilot piston is placed on the seat 25 with a defined force and thereby the pressure in the cylinder chamber of the Pressure relief valve limited to a predetermined value. Since the pressure relief valve 23 is parallel to the actuating cylinder is switched, there is also the pre-set pilot pressure PS there. The magnet 28 is more well known per se Proportional solenoid executed. This means that the actuating force of the punch 27 is proportional to that entered at 29 Electricity is. This makes it possible, by setting a specific electrical current at 29, a defined, dem Stream to achieve essentially proportional throttling of the oil flow.

REFERENCE SIGNS LISTING

1 housing

2 oil inlet

3 oil drain

4 inlet direction

5 direction of flow

6 throttle pistons

7 oil inlet duct

8 oil drain channel

9 Cylinder space for throttle piston, lock cylinder

10 follower pistons

11 control edge

12 leadership

13 actuating pistons

14 actuating cylinders

15 federal government

16 Stop on follower piston

17 Spring for follower piston

18 spring plates

19 Spring for setting piston

20 spring plates

21 pilot pressure channel

22 tank channel

23 Pressure relief valve

24 Control pressure channel to the pressure relief valve

25 valve seat

26 pistons

27 stamps

28 Rope magnet? 9 Input

30 tank channel

31 spring space

32 Seat of the throttle valve

33 Differential piston area of the throttle valve

34 dead path

Claims (3)

Bag. 1196 -ft- ^ fe- claims. Adjustable throttle valve consisting of: 1.1 A 2-way valve as a throttle valve, whose hydraulically operated throttle piston hydraulically applied on its remote from the throttle side Side through an inlet channel with the oil inlet and through an outlet channel with the Oil drain is connected, and on the throttle side with the pressure of the oil flow is acted upon; 1.2 a follower piston, which is connected to the drainage channel is guided in alignment and forms an edge control with this; 1.3 an adjusting piston, which is mechanically connected to the follower piston and in the opening direction of the follower piston is acted upon by the control pressure against a spring. License plate ; 1.4 The follower piston (10) penetrates the setting piston (12) and is used for mechanical purposes Connection to this at its end is a mechanical stop (16); 1.5 the follower piston (10) is spring-loaded in the closing direction independently of the setting piston (Spring 17). File number G 8C 17 273.2 Bag. 1196 2. Throttle valve according to claim 1, characteristic: Between the stop surface of the setting piston (13) and the stop (16) of the follower piston (10) there is a dead path (34). 3. Throttle valve according to claim 1 or 2, characteristics: The oil inlet channel (2) opens radially and the oil outlet channel (3) opens axially into the displacement of the throttle piston (6).